PATENTS

Dies sind die US-Patente von Dipl.- Ing. Hans- Joachim Wendt.

Sie sind jetzt abgelaufen und somit als Stand der Technik frei nutzbar.

This are the US-Patents from Dipl.- Ing. Hans- Joachim Wendt.

They are expired and can be used free as state of the art.

Computerized dispatching system

Abstract

A passenger buys his ticket at a station from a device which registers his destination and transmits the information to a central computer using the destination data to plot a travel path for a fleet of buses or other mass-transit vehicles. The arrival time of the next vehicle is indicated at each station; as the user boards such vehicle his destination is entered in a register therein. The central computer reads the vehicular memories by radio communication to modify, if necessary, the instructions given to the driver. Traffic density, average vehicular speed and the rhythm of traffic lights are also read into the central computer by way of supplemental information.

References Cited [Referenced By]

U.S. Patent Documents

Primary Examiner: Wise; Edward J.
Attorney, Agent or Firm: Ross; Karl F.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 453,545, filed Mar. 21, 1974, now abandoned, as a continuation-in-part of application Ser. No. 307,554 filed Nov. 17, 1972 and now abandoned.

Claims

I claim:

1. An automatic dispatching system for a fleet of independently driver-operated vehicles serving a predetermined area with a multiplicity of potential stops for said vehicles at fixed locations, comprising:

centralized computer means;

station equipment at each of said locations linked by a telecommunication channel with said computer means, said equipment including a destination selector operable by prospective passengers; and

information means aboard each vehicle in communication with said computer means, said information means including a register for the entry of stop identifications representing the destinations of passengers boarding the vehicle and station-indicating means for giving routing instructions to the driver of the vehicle, said computer means including logical circuitry and decision stages of a general-purpose computer programmed to evaluate data from the destination selectors at all said locations and from the registers aboard all said vehicles for operating said station-indicating means to route each vehicle to stops requiring service, while skipping stops not entered in the register thereof unless the destination selector at such stop is operated to report a prospective passenger, by the steps of

(a) determining whether any passenger aboard a given vehicle has the next stop as a destination,

(b) determining whether passengers are waiting at said next stop with destinations along the route traveled by said given vehicle,

(c) determining, upon a positive determination in step (b), whether said next stop is being served by another vehicle traveling the same route and having available space for said waiting passengers,

(d) upon a negative determination in step (a), and either a negative determination in step (b) or a positive determination in step (c), instructing the driver of said given vehicle to bypass said next stop.

2. A system as defined in claim 1 wherein said destination selector includes a ticket dispenser, said information means comprising a ticket reader connected to said register.

3. A system as defined in claim 1 wherein said station-indicating means is provided with driver-operated cancellation means.

4. A system as defined in claim 1, further comprising speed-sensing means aboard each vehicle communicating with said computer means, said equipment including display means controlled by said computer means in response to information from said speed sensing means to indicate the estimated arrival time of a vehicle headed for the respective stop.

5. A system as defined in claim 4, further comprising control means for traffic signals in the path of at least one vehicle, said computer means communicating with said control means for including the setting of said traffic signals in the calculation of said estimated arrival time.

6. A system as defined in claim 4, further comprising traffic-monitoring means along the path of said vehicles communicating with said computer means for the inclusion of traffic density in the calculation of said estimated arrival time.

7. A system as defined in claim 6 wherein said traffic-monitoring means comprises a vehicle counter at each of said locations.

8. A system as defined in claim 1 wherein said vehicles and said centralized computer means are provided with two-way communication means for handling inquiries from passengers.

9. A system as defined in claim 1 wherein said destination selector includes a panoramic map of the area served by said fleet and markings on said map representing the locations of said potential stops.

10. A system as defined in claim 9 wherein said markings are constituted by switches generating a selection signal for transmission to said computer means.

Description

FIELD OF THE INVENTION

My present invention relates to a dispatching system for a fleet of preferably trackless vehicles such as buses, limousines or taxicabs.

BACKGROUND OF THE INVENTION

Mass transit is becoming ever more difficult to organize efficiently in modern urbanized society. The use of private cars in city traffic has proven to be an impractical solution to the problem of moving vast numbers of persons to and from their jobs and about their business within the urban area. On the other hand, the transportation of large numbers of people in a limited area by public conveyances constitutes a problem which has to date never been solved satisfactorily since traffic patterns have been found to be unpredictable beyond any sort of coarse planning for heavy circulation during rush hours and light circulation during weekends and at night. Attempted solutions have all required the building of entirely new and extremely expensive overhead or underground systems out of the financial reach of many municipalities.

OBJECTS OF THE INVENTION

It is, therefore, an object of my present invention to provide an automated dispatching system of sufficient flexibility to adapt itself to widely varying traffic conditions.

Another object is the provision of such a system which can be applied to any existing fleet of preferably trackless vehicles.

SUMMARY OF THE INVENTION

These objects are attained, according to my present invention, by means of a dispatching system wherein a central computer is linked by telecommunication to each vehicle of a fleet and to a multiplicity of stations served thereby. The stations have ticket dispensers or other passenger-operated devices which supply the central computer with data on the number of persons waiting at each stop and on their destinations. This information is then compared with routing and loading information received from each vehicle and a tentative course is plotted for each vehicle which will take it in the most efficient manner through a complete run. The would-be riders at each station are informed of the arrival time of the next vehicle. When they board the vehicle, their target stations are reported to the computer by further passenger-operated means such as, for example, a ticket reader also serving as a cancellation device. This gives the computer a count on the load of each vehicle as well as a compilation of the destinations of its occupants, enabling it to modify the tentative course by skipping any stop not desired by an actual occupant of the vehicle if the persons waiting at such stop can be conveniently served by other vehicles traveling the same general route.

Advantageously, each station has a panoramic destination selector whereby the rider need merely actuate a corresponding switch or a pair of co-ordinated switches in order to receive his ticket upon payment of the requisite fare, if any, or the insertion of a token or a valid pass. An indicator at the station shows the prospective arrival time of the next vehicle bound for one or more stations along different routes.

The office of the automated dispatcher comprising the central computer may, according to another feature of my invention, also be provided with a display indicating the various routes with their stations and the instantaneous locations of all vehicles operating at the time. Advantageously, this central office includes a controller for the city's traffic lights responsive to signals from traffic sensors at the stations, these signals as well as the settings of the traffic lights being communicated to the computer which can therefore be programmed to let the vehicles bypass any traffic jams in their normal path.

In accordance with a further feature of the present invention, the central computer periodically samples the register aboard each vehicle into which the destination of every entering passenger is read. Associated with this register may be a display indicator controlled by the central computer in order to identify the next stop, or several stops, along with any incidental routing directions necessary (e.g. to detour a construction site). A cancellation button is actuated by the driver each time he arrives at the closest station shown on his indicator to enter this information in his register so that the next time this register is read by the central computer the various arrival times can be updated. A speed sensor on each vehicle may be in constant or intermittent communication with the central computer so as to aid in the calculation of arrival times.

According to another feature of the invention, the vehicles may be equipped with code transmitters and receivers to enable a passenger to check with the central computer about availability of transfer to other lines. This is achieved by feeding to the central computer a pair of multidigit code groups, one corresponding to the intended transfer point and the other representing the ultimate destination. The coded response from the central computer can be decoded and translated, for example, into an audible signal, or a central operator may reply by voice. The frequency of such inquiries may be evaluated by the computer to initiate possible route changes.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages of my invention will now be described in detail with reference to the accompanying drawing in which:

FIG. 1 is a schematic view of a central office and vehicular stations in a computerized dispatching system embodying my invention;

FIGS. 2 and 3 are block diagrams of the equipment at a station and aboard a vehicle, respectively, in the system of FIG. 1;

FIG. 4 is a flow chart for the program of a central computer in the system of FIG. 1;

FIG. 5 is a diagrammatic representation of a logic network forming part of the computer;

FIG. 6 is a diagrammatic representation of another logic network included in the central computer; and

FIG. 7 is a block diagram illustrating a further logic network.

SPECIFIC DESCRIPTION

As shown in FIG. 1, a transit system according to the invention includes a multiplicity of stations 25, individually designated A through H, all connected via communication channels 3 (radio links or transmission lines) to a central office 26. Several vehicles 30 are shown in an area monitored by the computer and are individually designated I, II, III. Traffic lights 31 in the area served by the system are connected to a controller 28 at the central office by lines 4. All stations 25 may be laid out so that they are only 200 to 400 meters away from any given point in the community.

The central station 26 has at its heart a computer 1 connected through a coder/decoder 2 to the communication channels 3 and to the traffic-light controller 28. This computer 1 is also connected through a further coder/decoder 7 to a transmitter 8 and a receiver 9 for radio communication with the vehicles 30 as will be described below. An input/output device 5 is connected to this computer 1 for programming it and reading out information while a traffic display 6 also controlled by the computer allows an operator at office 26 to see at a glance just how the transit system is functioning.

As shown in FIG. 2, each station 25 has a destination selector 10 exhibiting a map of the system and bearing pushbutton switches 32 at points on the map corresponding to the other stations. This selector 10 works in a coder/decoder and register 11 which is connected via the associated communication channel 3 to the central office 26. A fare collector 16 and a ticket dispenser 13 are controlled by selector 10, the dispenser issuing a ticket only upon insertion of one or more coins or tokens (in an amount displayed by the collector on instruction from the selector) or presentation of a pass to a scanner not shown. An answer-back unit 14 (e.g. an illuminated sign) reports the arrival, from the central office, of a signal confirming the processing of the destination selection by the computer 1; if this signal is not forthcoming, the prospective rider may press a button on selector 10 to cancel the booking made and to recover his fare, such cancellation being prevented by the reception of the answer-back signal in register 11. A signal from the computer, also stored in that register, operates an indicator 12 to display the expected time of arrival of the next vehicle headed for the selected destination or, possibly, for an intermediate transfer point.

A street intersection 33 adjacent the station 25 is kept under surveillance by a traffic monitor 17 comprising lamps 19 and electric eyes 18 that count the passing vehicles. Their count is averaged by a conventional integrator and fed through the coder/decoder and register 11 to the central office 26. Alternatively, I may use a traffic-density detector 17 as disclosed in U.S. Pat. No. 3,536,900 which translates its raw data into a measure of delay and sends this calculation to the central computer 1.

In each vehicle a further register 20 is provided as shown in FIG. 3. This register 20 is connected through a coder/decoder 22 to a transceiver 23 communicating through the associated two-way radio link with the central transmitter 8 and receiver 9. A ticket reader 21 feeds destination information into the register 20 so that the central computer 1, upon periodically sampling this register, may know how many passengers have boarded and whither they are bound. Register 20, on information from the central office, also sets a visual indicator 34 viewable by the operator of the vehicle 30 to show him the next-following stop or stops. This indicator is provided with a cancellation button 35 which the operator depresses each time he arrives at a station to delete the corresponding stop indication and to transmit to the central office 26 a signal from which the computer can determine the vehicle's subsequent course. A speed sensor 24 working into the register 20 may also furnish the central computer 1 with further information enabling it to calculate, on the basis of the vehicle's position and the traffic-light timing as well as the traffic density, the expected arrival time at its next stop or stops for transmission of this information to the station or stations concerned.

The coder/decoder 22 is also connected via an interface unit 38 to an inquiry input 36 (e.g. a keyboard or a dial) and a speaker 37 serving as information output. Inquiries about transfer connections, which may be initiated by dialing a number identifying the central office, are fed into the transceiver 23; the answers, delivered by the computer with or without the intervention of a human operator at the central office, are announced through the speaker 37.

I shall now describe, with reference to FIGS. 4-7, details of a program 39 for performing the more significant operations of my dispatching system by means of computer 1. Program 39, diagrammed in FIG. 4, makes use of an input register 40 containing information bits in data stages 41-45; decision stages 46, 47, 48, 51, 55 and 57; buffer stages 50, 52 and 59; a memory 54; logic steps 49, 58, 60, 61 and 63; and logic networks 56, 62 and 64. The data stored in register 40 may be updated by new information obtained on any run-through; the answers to the questions posed by the decision stages, either "yes" or "no", determine the subsequent course of that particular run-through by proceeding to different steps depending on the answer received on the basis of current data. The buffer stages call forth the required information from the vehicle and station inputs when addressed; the logic steps are conclusions which necessarily follow from the preceding sequence. The logic networks determine aspects of the program not answered by simply calling up information stored in binary form. Except for these logic networks, more fully described with reference to FIGS. 5-7, all the components of FIG. 4 are conventional components of a general-purpose computer.

The program 39 is activated each time a driver of one of the vehicles 30 has reached a stop and presses a cancellation button 35. The relevant information, delivered in coded form to the input register 40, includes the number V.sub.A of vehicles currently in service (41), the basic route plan of the day (42), points of departure and destinations of passengers aboard (43), its instant position P.sub.F (44), and its direction R.sub.F (45). The first program step 46 determines whether any passengers aboard the vehicle have the next stop H(P.sub.F+i) as a destination. If the answer to question 46 is "yes", the program advances to buffer stage 50 where the number of persons debarking at the next stop is determined from input data 43 and sent to memory 54 for storage until needed. If the answer to program step 46 is "no", step 47 determines if another vehicle is already serving stop H(P.sub.F+i), if so, step 48 determines whether that vehicle has free space. If this is also answered affirmatively, position P.sub.f is advanced to P.sub.f+l in step 49 and the program returns through logic network 62, which will be discussed subsequently, to input register 40 where it may be reactivated for the new position P.sub.F whenever the driver presses cancellation button 35 again. The stop from which button 35 is pressed to activate program 39 is referred to as H(P.sub.F+j).

If the answer to either step 47 or 48 is "no", the program advances to step 51 as it does after step 50. Step 51 determines from input data 43 whether any prospective passengers at the upcoming stop want to travel in the direction of the present vehicle; if so, step 52 specifies how many passengers wish to board and sends the information to logic network 62 as well as to memory 54. The information stored in that memory enables a determination in step 55 if the sum of the numbers of would-be riders and passengers remaining aboard is greater than the capacity of the vehicle. If the answer to step 55 is "yes", logic network 56 is activated and, utilizing the data collected from traffic-density monitors 17 (which may be of the type disclosed in U.S. Pat. No. 3,536,900) in conjunction with the data bits in stages 44 and 45 (which store the updated vehicle locations and directions, respectively), determines the waiting time for the overflow passengers until the next available vehicle arrives. This waiting time is compared with a preselected maximum waiting time in step 57. If a "yes" answer appears in step 57, i.e. if the present waiting time exceeds the preselected maximum, the signal is transmitted to step 58 where the command V.sub.A = V.sub.A+1 is given, adding another vehicle to the route at the overflowing stop H(P.sub.F+i) as this information is transmitted back to the input register 40 through logic network 62. If the answer to program step 51 is negative, i.e. if there are no passengers waiting at stop H(P.sub.F+i) for direction R.sub.F the program advances directly to step 61, where i becomes i+1, and the cycle is ready to be restarted with the new i value in register 40 (after the information passes through logic network 62). If step 51 is answered affirmatively but the number of persons waiting for the vehicle does not cause an overflow, the answer to step 55 is negative; this sends the program to step 60 where j = i, the upcoming stop becoming the present stop, subsequently augmenting the designation of the value of i by +1 and completing the program in the manner discussed. If a passenger overflow is brought about by those wishing to board ("yes" at step 55) but the projected waiting time calculated in logic network 56 is not great enough to warrant adding a vehicle to the route (the answer at step 57 being "no"), the projecting waiting-time increase is recorded in step 59 and the program advances through step 60 in a manner similar to that described above.

Logic network 62, as diagrammed in FIG. 5, is included in the program 39 in order to remove vehicles from service when the number and location of passengers no longer warrants the use of all vehicles in service at the time. Signals from program steps 49 (F=F+1), 58 (V.sub.A =V.sub.A+1) and 61 (i = i+1) are first fed to a counter 70 which clears itself and restarts after a count of x pulses from the three aforementioned stages. Counter 70 contains an accumulator 71 which stores pulses from step 49 and emits a signal setting a flip-flop 72 after accumulating a smaller number y of pulses, but the accumulation is restarted each time counter 70 is cleared. The signals from steps 49, 58 and 61 also bypass counter 70 and continue on to input register 40 where they inscribe their respective information changes and ready the program 39 for a new cycle. The signal from step 58, which adds a vehicle to the transit zone, sets flip-flop 72 in addition to returning to input register 40, as does the collection of y pulses from step 49 in accumulator 71. Flip-flop 72, when set, energizes one input of each of four AND gates 73, 74, 75, 76. The other inputs of AND gates 73 and 74 receive signals from steps 49 and 61, respectively, these gates working into an OR gate 77 also receiving pulses from step 58 which bypass the flip-flop 72 as well as serve to set it. Signals energizing the other inputs of AND gates 75 and 76 are derived from the decision stages of the program. A "no" answer from step 51 (no passengers wanting the approaching vehicle) energizes the second input of AND gate 75 while a "yes" answer causes the waiting passengers to be counted in step 52, the count being fed into a comparator 53 which produces an output (1) if the number waiting is less than a predetermined percentage p of the vehicle's capacity, as selected in a reference register 53a (FIG. 4), and no output (0) if the number waiting is greater than this percentage. An output (1) energizes the second input of AND gate 76. AND gates 75 and 76 work into an OR gate 78. OR gate 77 receives a signal pulse each time a program run is completed when flip-flop 72 is set, and transmits these pulses to a counter 79 which counts up to z pulses, at which point it emits a signal resetting the flip-flop 72 and clearing the counter 79. Another counter 80 is fed by signals from OR gate 78 and AND gate 73, and emits a signal pulse when the count reaches w pulses which, in addition to resetting the flip-flop 72 and clearing the counter 80, activates step 63 in the program to perform the operation V.sub.A =V.sub.A-1 which takes a vehicle out of service.

This circuit receives the results of every program run in its first counter 70 and reviews the need for the number of vehicles in use when the flip-flop 72 is set, which occurs either when a vehicle is added (at step 58) or when a significant percentage (greater than y/x, since y is reached before x) of vehicles may bypass a stop served by another vehicle (step 49). In such a case, the second counter 79 receives pulses for each program run while the third counter 80 receives an input for each case of apparent vehicular redundancy (including step 49, AND gate 75 conductive with no passengers waiting, and AND gate 76 conductive when those waiting constitute less than p percent of capacity). If the percentage of times a vehicle is considered redundant is greater than w/z (i.e. if w in counter 80 is reached before z appears in counter 79), an instruction to take a vehicle out of service will be given at step 63 as the counters are cleared and the flip-flop 72 is reset; if z is reached first, step 63 will not be activated as the cycle is restarted.

FIG. 6 is a diagrammatic representation of the logic circuit 64 which replies to transfer inquiries to the central computer 1 from passengers on the vehicles. Transceiver 23 of vehicle register 20 communicates the transfer inquiry, including the stop number and the direction desired, to the central computer 1 where it is received by a register 81 which sends a coded signal, similar to the bits of stages 44 and 45, to program step 47 ["Is there a vehicle at stop H(P.sub.F+i) traveling in direction R.sub.F ?"] and also activates a monostable multivibrator or monoflop 82. This operation consists of evaluating first the location inquiry on the basis of the contents of stage 44 in a comparator 83 and then the direction inquiry on the basis of the contents of stage 45 in a comparator 84. The pair of responses are fed to the inputs of a NAND gate 85 and an AND gate 86 in parallel therewith, a "yes" answer causing an output from AND gate 86 (correlation in both comparisons) and a "no" answer causing an output from NAND gate 85. On "yes" the program proceeds to step 48 which, like step 47, comprises a NAND gate 87 and an AND gate 88 in parallel therewith. These gates have inputs energized by AND gate 86 on a "yes" response at step 47 and by input register 40. Depending on whether there is space in the vehicle, AND gate 88 or NAND gate 87 conducts to provide a "yes" or a "no" response. A "no" answer at step 48 joins the signal path of "no" at step 47, whereas a "yes" response would lead to restarting the program with F = F+1 at step 49; however, these responses must be cut off from the rest of the program 39, as a transfer inquiry does not constitute an actual program run-through. For this reason, NOR gates 89 and 90 have inverting inputs connected to the outputs of NAND gate 85 and AND gate 88, respectively, the other input of each NOR gate being connected to the output of monoflop 82. The signal from monoflop 82 in combination with either a "no" or a "yes" response to step 48 (taken before being inverted) unblocks an AND gate 93 or 94, respectively, both of which work into a flip-flop 95 to energize its "yes" output (1) or "no" output (0), respectively, sending the signal back to vehicle register 20 through transceiver 23.

Logic network 56, which determines waiting time for the next-arriving vehicle 30, has been shown in FIG. 7 as comprising a delay register 100 fed by the traffic-density monitors 17, e.g. in the manner disclosed in U.S. Pat. No. 3,536,900, located at each stop. The activation of register 100 sets a monoflop 101 which checks the location and direction of all vehicles in service by calling forth the information stored in data stages 44 and 45, respectively. The direction desired by delay register 100 and that of the first vehicle inscribed in input register 40 are fed into a comparator 102. If they differ, the negative comparator output summons information about the next vehicle inscribed in register 40 and the process begins again. If the desired direction and the vehicle direction agree, the comparator output energizes one input of a multistage comparison network 108. The locations of the station and vehicle in question, translated into binary codes indicating their distance from a predetermined, arbitrary point of origin along the basic route 42, are fed into respective inputs of a comparator 103 which gives a positive output if the numerical value of the stop code is greater than that of the vehicle code; otherwise, its output is negative. This output, of either polarity, reaches one input of a comparator 104 whose other input receives a code designating the direction desired at the stop in question as stored in register 100. An output from comparator 103 opens either of two gates 105 or 105a to enter the numerical value of the stop code or the vehicle code, whichever is larger, as the minuend and the other value as the subtrahend in a subtractor 106 which determines the distance between the stop and the vehicle by adding the binary complement of the subtrahend to the minuend, as is well known in the art. Comparator 104 concurrently determines if the calculated distance between these locations lies in the same direction as the vehicle is traveling, which is the case if its inputs agree as stated above. If they do not, as indicated by a negative output from comparator 104, the effective distance between stop and vehicle becomes the total route length less the calculated distance; thus, a negative output from comparator 104 opens a gate 113 leading to a subtractor 107, which calculates this new distance by adding the binary complement of the result obtained by subtractor 106 to the total route length c as stored in a source of reference voltage 107a; a positive output from comparator 104 opens a gate 113a to bypass the subtractor 107.

This calculated distance is supplied to the second input of the first stage 108a of comparison network 108 whose first input is energized by a positive output from comparator 102 consisting of a binary code a. If the calculated distance is less than or equal to the numerical value of code a, a zero output will result, energizing one input of a second-stage comparator 108b which consists of a binary code b; if the calculated distance is greater than a, one input of another second-stage comparator 108c will be energized in like manner. The calculated distance reaches the second inputs of all of the units of network 108. In a manner similar to that described, the positive and negative outputs of units 108b and 108c energize one input each of third-stage comparator units 108d, 108e, 108f and 108g, respectively. These four units have a total of eight outputs, ranging from the "0" output of unit 108d, which represents the smallest increment of distance as the result of three successive "less than or equal to" responses, to the "1" response of unit 108g, indicating the greatest distance increment by three "greater than" responses. The several distance increments may be represented by binary 1 through 8 for the eight possible outputs, i.e. 1000 (8) for the smallest increment through 0001 (1) for the largest. These results, in conjunction with a vehicle-identification code, are fed into a memory 109 wherefrom a selector 110 chooses the highest number after all vehicle codes have been entered. The selected distance increment is then fed to one input of an AND gate in a matrix of such gates forming part of a correlator 111, the delay determined by traffic-density monitor 17 and reported to register 100 being fed to the other gate input. The several AND gates of correlator 111 determine all possible combinations of distance increments and delays; based on statistics which can be periodically updated, the output of each AND gate representing a particular distance-increment/delay combination reads out a predetermined waiting time from an output register 112, this information being sent on to the next stage (step 57) of the program.

Let us assume, by way of example, that the vehicle I loading at station A has no passengers for stations B and C but is being boarded by a large number of passengers headed for stations D and H. A prospective rider is waiting at station C, intending to go to station E. Vehicle II, which at this instant is approaching station C, has five riders wishing to go to station E and one desiring to reach station F. The computer 1 thereupon determines that vehicles I should skip stations B and C and should proceed toward stations D-F-G-H, bypassing the out-of-the-way stop E, while vehicle II picks up the rider at station C. One of the passengers aboard vehicle I, ticketed for station E, then inquires about transfer possibilities at interchange D, dialing first the code of the central office 26 and thereafter successively the codes of stations D and E. He is then advised that vehicle II, now en route from station C to station D, will wait for him at station D to take him to his destination. The rider desiring to go to station F leaves vehicle II at station D and learns from the display indicator 12 thereof that the next vehicle headed his way will arrive shortly, this being vehicle I whose driver is now instructed by the computer to stop also at station F. In traveling toward his final stop H, the driver of vehicle I ignores a group of ticket holders at station G who want to go to station D and will be picked up by vehicle III moving in the opposite direction.

Apparatus for loading and unloading an aircraft and ascertaining the weight of the load

Abstract

The present apparatus is used for ascertaining the individual weight of any type of load including that of passengers and of hand baggage, that is added to the total payload of an aircraft. Each individual weight is ascertained and, if desired, displayed and added up to ascertain the total weight. For this purpose a weight sensing device such as a group of load cells or the like including a platform is arranged at the entrance to the freight or baggage compartment and, in a passenger aircraft at each passenger entrance door inside the aircraft. The weight sensing device provides an electrical signal for each weight unit that passes the platform into the aircraft. The weight representing electrical signal is supplied to an adder and to a display unit where the individual weights are displayed as well as the total weight. Further, control signals may be derived from the individual weight representing signals and control signals may be provided through a keyboard for energizing drive rollers or conveyors which transport a freight container or the like to a predetermined freight stall and for lashing the container down in its stall.

Foreign Application Priority Data

References Cited [Referenced By]

U.S. Patent Documents

Primary Examiner: Wise; Edward J.
Attorney, Agent or Firm: Fasse; W. G., Gould; D. F.

Claims

What is claimed is:

1. An apparatus for loading and unloading an aircraft and for ascertaining the weight of the load, comprising weighing station means arranged within the aircraft fuselage in such position that the weight of any item of payload to be added to the actual weight of the aircraft must operatively and individually pass said weighing station means for individually measuring the weight of each payload item entering the aircraft, load cell means in said weighing station means to provide individual weight representing electrical signals, electronic logic circuit means, and conductor means operatively connecting said electronic logic circuit means to said load cell means for producing from said individual weight representing electrical signals respective control signals.

2. The apparatus of claim 1, further comprising lashing means (17) for securing a weight in a fixed position in the aircraft, and circuit means operatively connecting said lashing means to said electronic, logic circuit means for automatically securing said lashing means when a weight is placed in proper position relative to said lashing means.

3. The apparatus of claim 1 or 2, further comprising weight position reporting means (20) operatively connected to said electronic, logic circuit means for supplying a position signal to said electronic, logic circuit for signifying the placing of a weight in a proper location relative to said weight position reporting means.

4. The apparatus of claim 3, wherein said weight position reporting means (20) comprise light source means (45), light sensing means (47), and optical means operatively arranged to supply the light from said light source means to said light sensing means to form a light barrier which provides said position signal when a weight is placed in proper position.

5. The apparatus of claim 1, further comprising indicator means (15) comprising a plurality of display positions (53) corresponding to respective load receiving positions in the aircraft, means operatively connecting said indicator means to said electronic, logic circuit means whereby the weight of a load item placed in said load receiving position is displayed in the corresponding display position (53).

6. The apparatus of claim 5, wherein said indicator means further comprise total weight display means (54) and overload warning display means (53).

7. The apparatus of claim 1, wherein said weighing station means is arranged for weighing passengers.

8. The apparatus of claim 7, further comprising door threshold means, said weighing station means being incorporated into said door threshold means for weighing passengers.

9. The apparatus of claim 7, further comprising passenger seat means, said weighing station means being arranged for cooperation with said passenger seat means for weighing passengers.

10. The apparatus of claim 1, further comprising data input keyboard means operatively connected to said electronic, logic circuit means for supplying information data to said electronic, logic circuit means to determine the center of gravity for the aircraft in accordance with the weight ascertained from said loading.

11. The apparatus of claim 1, further comprising control input keyboard means and freight container transport means including drive means for said transport means, means operatively connecting said control input keyboard means to said drive means for operating the latter.

12. The apparatus of claim 11, wherein said control input keyboard means comprise pressure sensitive control keys including synthetic material elements having a pressure dependent electric conductance.

13. The apparatus of claim 1, wherein said conductor means comprise cable means capable of simultaneously constituting power supply means and digital signal transmitting means.

14. The apparatus of claim 13, wherein said conductor means comprise simple coaxial cable means suitable for signal transmission by carrier frequency techniques.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for loading and unloading an aircraft and for ascertaining the weight of the payload.

For an efficient operation of commercial aircraft such as passenger and/or freight aircraft, it is necessary for an optimal planning of any flight that the pilot receives a weight information that is as precise as possible with regard to the payload and also with regard to the load distribution within the aircraft. Such information makes it possible to determine the required fuel quantity for any particular flight much more precisely than is customary heretofore. If no exact data regarding the payload are available, it is necessary to load the aircraft with an additional fuel quantity for safety purposes. Under normal operating conditions such additional fuel quantity is not used up at the end of a flight. The carrying of additional fuel adds to the weight of the aircraft and hence, results in an increased fuel consumption which should be avoided.

It is customary to ascertain the total weight of the freight by weighing the individual freight containers and pallets by means of scales on the ground in an airport. However, such weighing on the ground has certain disadvantages. The weighing stations are not uniformly available at all airports. Further, the passenger weight is only approximated by multiplying an average passenger weight by the number of passengers on any particular flight. Such average weight is not very precise, especially where the average weight employed requires corrections. Besides, the total weight of hand baggage carried by the passengers may also be substantial.

Prior art freight loading and unloading systems have the advantage that they permit the conveying of the individual freight pieces such as containers, pallets, and so forth from the freight gate to the individual loading positions and in the reverse direction by means of roller drives or the like. However, such prior art power driven conveying devices do not provide the possibility of checking the weight of the freight that is being loaded into an aircraft or that has been removed from an aircraft. Thus, heretofore it has not been possible to avoid localized overloading of the freight space structure. It is, however, desirable, that the freight should be distributed substantially uniformly over the available loading space.

A known method of ascertaining the weight of the total payload in an aircraft measures the load that is effective on the landing gear, please see U.S. Pat. No. 3,584,503 issued June 15, 1971. In this method the load applied to each individual landing gear leg is ascertained by measuring a force and then determining the total weight of the aircraft from such measurements. The empty weight of the aircraft and the weight of the fuel is then deducted from the so ascertained total weight to obtain the payload. Such weight ascertaining systems are known as so-called weight and balance systems and are also capable of ascertaining the location of the center of gravity of the aircraft. However, the data representing the payloads are relatively not too precise because they have been ascertained through first measuring the total weight. Besides, such systems are not capable of providing any information regarding the weight of individual load items nor information regarding the weight distribution.

OBJECTS OF THE INVENTION

In view of the above it is the aim of the invention to achieve the following objects singly or in combination:

to provide an apparatus for the loading and unloading of an aircraft which is capable of ascertaining the weight of the load during the loading operation as precisely as possible including the total weight and the weight of individual load items as well as the weight distribution;

to increase the speed of the loading and unloading operation while simultaneously reducing the danger of accidents;

to indicate the position of the center of gravity of an aircraft as a result of the ascertained individual weights added to the payload of the aircraft;

to provide a warning signal showing if any local overloading of the freight space structure has occurred;

to provide precise data enabling the determination of the fuel quantity required for any particular flight; and

to move the individual freight items with a speed controllable in such a manner that the loading or unloading speed may be adapted to the instantaneously prevailing conditions whereby the maximum speed may be higher than the presently prevailing conveyor speeds in the prior art.

SUMMARY OF THE INVENTION

According to the invention there is provided an apparatus for loading and unloading an aircraft and for ascertaining the weight of the load comprising weighing station means arranged in such positions in the aircraft that any weight to be added to the payload of the aircraft must operatively pass said weighing station means, load cell means in said weighing station means to provide weight representing electrical signals, electronic, logic circuit means, and conductor means operatively connecting said electronic logic circuit means to said load cell means for evaluating said weight representing electrical signals to provide respective control signals. In addition, the apparatus comprises conveying or transporting devices for the freight, arranged for cooperation with the weighing station means. Further, freight lashing mechanisms are provided on board the aircraft.

The weighing results are displayed on a display showing the weights of individual freight items as well as the total weight. The display of the individual freight items is arranged in such a manner that a graphical illustration of the freight space is combined with the individual display windows. Stated differently, each display window designates a particular freight position or stall in the freight space of the aircraft. All operating instructions which, for example, may be supplied through a keyboard, and all measured results are processed through a control logic circuit arrangement such as a microprocessor which supplies the necessary signals to the further components of the apparatus such as the display devices, the speed control for the conveyor means and the like.

The signals are processed in the form of digital signals and are transmitted by at least one carrier frequency. Thus, it is possible to realize all information transmitting paths by means of coaxial cables which may be simultaneously utilized to provide the power supply for the active components of the system.

BRIEF FIGURE DESCRIPTION

In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective, yet somewhat schematic view of a freight space area inside an aircraft including means for loading and unloading the freight space in accordance with the invention;

FIG. 2 is a block circuit diagram of the control system according to FIG. 1;

FIG. 3 is a sectional view through a weight sensor forming a load cell for the weighing system;

FIG. 4 is a block circuit diagram of the electronic circuit arrangement of the weight sensor or load cell according to FIG. 3;

FIG. 5 illustrates in block form the components of the control logic circuit of FIG. 2;

FIG. 6 is a block circuit diagram of the components forming a light barrier for the freight position report means of FIG. 2;

FIG. 7 is a more detailed block circuit diagram of the display means of FIG. 2;

FIG. 8 is a sectional view similar to that of FIG. 3, however, showing a pressure sensor useful as a control button.

FIG. 9 shows a circuit diagram illustrating further details of the block diagram of FIG. 5;

FIG. 10 is a circuit diagram of a display unit, that may be used for the present purposes;

FIG. 11 illustrates the arrangement of an indicator and control panel also shown in block form in FIG. 2;

FIG. 12 shows an example of a suitable, conventional analog-to-digital converter;

FIG. 13 shows the wiring of an encoder decoder circuit also shown in block form in FIG. 5; and

FIG. 14 shows the wiring of a memory circuit shown in block form in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE OF THE INVENTION

FIG. 1 illustrates a somewhat schematic, perspective general view of the freight space in an aircraft incorporating an example embodiment of a system according to the invention for the loading and unloading of such aircraft. A door 9 lead into the freight compartment. Guide rails 1 near the gate or door 9 lead a freight container, not shown, onto a platform supported by weight sensors 5 to be described in more detail below. The platform with the weight sensors 5 may be covered by so-called ball bearing mats 2. Longitudinal drive rollers 3 extending across the width of the freight compartment are provided for transporting a freight container in the direction of the longitudinal axis of the freight compartment. Further, drive rollers 4 extending with their longitudinal axis in the direction of the longitudinal axis of the freight compartment are provided for moving a freight container or the like across the width of the freight compartment.

The freight compartment is divided into freight positions or stalls indicated as 7, 7a, 7b, 7c, through 7k. The just mentioned freight positions or stalls are located adjacent to longitudinal roller conveyors 10. Further longitudinal drive rollers 3 are located in the area of these freight positions. Each freight position is equipped with a freight lashing or latching mechanism 6 known as such and capable of securing, for example, a pallet or freight container to the loading floor of the freight compartment. Such lashing devices 6 may be installed recessed below the level of the freight floor or they may be installed on top of the freight floor as is well known in the art.

When loading, for example, a freight container into the freight compartment through the open door 9, the container is placed on the guide rails 1 and moved along such guide rails toward the ball bearing mat 2 until the rollers 4 contact the container and move it into the freight position 7k. When the container has taken up the position 7k the drive means are manually switched off by the operator and the weight of the container is ascertained by means of the weight sensors or load cells 5. Thereafter, again manually, the drive rollers 4 are switched on to move the container, for example into position 7e. Thereafter the longitudinal drive rollers 3 are switched on to move the container to position 7. Whereby the roller conveyor means 10 reduce the friction between the moving container and the freight floor. If the container has taken up its intended position, for example position 7, all drive means are switched off and the respective latching mechanism 6 is activated to secure the freight container in position. The latching mechanism may, for example, comprise magnetically operated hooks which engage respective recesses of the freight container as is well known in the art. When container positions 7 to 7e are fully occupied, the following containers will, in the same manner as described in the foregoing, be moved into their respective positions 7f to 7k. The last container is placed, for example, in position 7k and is latched in position in the same manner as all the other containers. The unloading takes place in the same manner only in the reverse, whereby the weighing step is omitted.

The activation and deactivation of the various drive means 3, 4 is accomplished by operating switches 8 for closing and opening respective drive energizing circuits for the motors 3', 4' shown in FIG. 2. The switches 8 are also shown in FIG. 2. The arrangement may be such that the respective motors are energized as long as an operator depresses the corresponding switch 8. These switches may be constructed as will be described in more detail below with reference to FIG. 8. By driving the motor 3', 4' only as long as the corresponding switch 8 is depressed and by locating the switches 8 at such a level, that only a standing operator can depress a switch 8, a safety feature is provided in that a container cannot roll over an operator who may have fallen by accident to the freight floor.

FIG. 2 illustrates a block circuit diagram of the electronic control apparatus according to the invention primarily comprising the above mentioned operating switch 8, corresponding high pass and low pass filter means shown in a common block 18, a main control panel 14, a control logic circuit 13 and a motor control 16 for activating the drive motor 3', 4', whereby the actuation of any of the switches 8 results in a control signal passed through the control logic circuit 13 and the motor control 16 of conventional construction. A display unit or indicator 15 is also connected to the control logic circuit 13 for indicating the ascertained weights of the individual freight items or of the individual passengers as well as for indicating the total weight as ascertained by the weight sensors 5 which are also operatively connected through respective high pass filter and low pass filter means 19 to the control logic circuit 13. A position or rather freight position report mechanism 20 is also connected to the logic circuit 13 for indicating which freight positions 7, 7a, 7b, 7c, through 7k have been filled. An automatic lashing mechanism 17 receives its control signal from the logic circuit 13 in response to respective input instructions from the operator through the main control panel 14 or in response to a signal received from the position report mechanism 20. A power supply unit 12 is connected to the logic circuit 13 and supplies all components of the system with the necessary power. For this purpose the main control panel 14, the weight sensors 5, the indicating unit 15, and the motor control unit 16 are operatively connected to the logic circuit 13 by means of coaxial cables which transmit the respective information or control signals by means of a modulated carrier frequency. These cables simultaneously supply the power necessary for operating the various active components of the system.

In operation, if a freight container is to be placed into the freight compartment of an aircraft, the operator first activates through a respective switch 8, the motors 4' for moving the container with the respective rollers 4 across the loading floor until the container takes up the desired position on the ball bearing mat 2 and/or platform 2' of the weight sensors 5 as shown in more detail in FIG. 3. In this position each container is weighed. In response to a corresponding initial instruction by the operator at the main control panel 14, the control logic circuit 13 interrogates each weight sensor 5 for transmission of any weight values ascertained by the sensors 5 through the logic circuit 13 to the indicator 15 to be described in more detail below with reference to FIG. 7. The indicator 15 permits reading off the individual container weight from a display field or position. Thereafter, the container is moved to a specific freight location 7, 7a, 7b, 7c, through 7k, as mentioned above. Each drive motor 3' corresponds to a respective operating switch 8 which may be numbered from l to "n" in the same manner as the corresponding motors. Each operating switch 8 may comprise a button for forward or reverse rotation of the respective drive roller and motor. In addition, each switch 8 comprises an address encoder which provides in addition to the forward or reverse rotation information, an address information of the motor to be energized. The address information corresponds to the respective location 7 to 7k and such address information is also supplied to the control logic circuit 13 through the respective filter means 18, whereby the control logic circuit 13 energizes the respective motor through the motor control circuit 16. When the container has reached the position which was designated by the actuation of the respective switch or button 8, the control circuit 13 switches the motor off and simultaneously the automatic lashing device 17 receives an instruction signal for lashing down the container in the position as designated by the initial actuation of the respective switch 8. Thus, the container remains lashed down by the respective lashing device 6 against any displacement during the flight and until loading.

Each loading position or stall 7, 7a and so forth comprises means for reporting the placement of a piece of freight in the respective position. These freight position report means 20 provide an occupied signal to the logic circuit 13, whereby the latter makes sure that a container which is presently being advanced cannot collide with a container already occupying a freight position or stall. The freight position report means will be described in more detail below with reference to FIG. 6.

FIGS. 3 and 4 illustrate an example embodiment of the weight sensors 5 and the respective circuit arrangement for such weight sensors as are used, for example, in FIG. 2. Each weight sensor comprises mainly a lower housing member 21 and a cover member 22 operatively secured to a platform 2' through threaded bolts 39. The platform 2' may be installed next to the freight loading door 9 or next to a passenger entrance door and will perform the same function in both instances. The load cell or pressure sensor 5 further comprise a pressure sensitive synthetic material conductor 23 operatively interposed between two metal plates 24 and two insulating plates 25 and electrically connected with its output terminals to electronic circuit means 26, such as an amplifier, by conductors 27. The lower housing member 21 is, for example, secured to the floor of the freight compartment, for example, by screws 28. The ball bearing mat 2 may be directly connected to the cover 22 of the pressure sensor 5, whereby the ball bearing mat 2 would take the place of the platform 2'. However, the ball bearing mat 2 may also rest on the platform 2'. Where the weighing device is installed adjacent to the entrance door of a passenger compartment, the platform 2' may form a door threshold which in turn may be covered by a floor mat or the like.

The cover 22 in any type of installation of the sensors 5 is movable in the "z" direction as indicated in FIG. 3, namely, vertically up and down relative to the lower housing member 21 whereby the synthetic material conductor 23 is exposed to the load exerted by a weight effective through the metal plates 24 and the insulating plates 25. The synthetic conductor material has such a characteristic that its electric conductance increases proportionally to the weight placed on the platform 2' or on the ball bearing mat 2, whereby a weight representing electrical signal is provided at the output terminal 29 which may be a coaxial cable plug secured to a housing wall 25' of the lower housing member 21.

FIG. 4 illustrates a circuit arrangement for processing the output signal of the weight sensors 5, whereby the synthetic material conductor 23 forms part of a bridge circuit 13, the output signal of which is supplied through an amplifier 32 to an analog-to-digital converter 33. The components shown in FIG. 4 may be integrated into the circuit 26 shown in block form in FIG. 3. The weight representing digital signal at the output of the A/D converter 33 is supplied to an input encoder 34 which adds to the particular weight representing signal a code word or flag which correlates the weight signal to the particular weight sensor. The code word or flag is a further digital signal and the complete signal comprising the weight information as well as the identification of the weight sensor is supplied to a modulator 35 only when the encoder 34 has received a release signal provided by an address decoder 38. The modulator 35 in turn is connected to a carrier frequency generator 36 which generates a carrier wave modulated by the above mentioned signals. The output of the carrier frequency generator 36 is connected to the high pass and low pass filter means 19 shown in FIG. 2 and the output of such filter means 19 is connected through a coaxial cable 29' to the control logic circuit 13 as shown in FIG. 2. The carrier wave passes through the high frequency filter portion of the filter means 19. The logic circuit 13 stores the received information for the various operations to be performed by the logic circuit 13 as will be described in more detail below. Referring further to FIG. 3 the weight sensor 23 supplies the measured value signal only then to the coaxial cable 29' when the sensor 23 has received an addressing or interrogating signal from the circuit 13. This interrogating signal is also a digital signal and is supplied by way of a correspondingly modulated carrier wave through the coaxial cable conductor 29' and the high pass portion of the filter means 19 to a carrier frequency receiver 37 which supplies the received interrogating signal to an address decoder 38. The address decoder 38 compares the address information forming part of the interrogating signal with the address of the particular pressure sensor. If the two addresses correspond, the address detector 38 supplies a respective release or gating signal to the address encoder 34 which thus supplies the weight and adress signal to the modulator 35. Thus, the signal passes through the circuit in the just described manner to the coaxial cable 29' and to the logic circuit 13.

The weight sensor electronic circuit 26 as just described is supplied through the coaxial cable 29 with a d.c. voltage passing through the low pass portion of the filter means 19 to a stabilizer circuit 31 which produces a sufficiently stable operating voltage for the bridge circuit 30 as well as for all active components of the circuit arrangement shown in FIG. 4. For this purpose an output 31' is connected to each of the active components of FIG. 4.

FIG. 5 shows a block diagram of the control logic circuit 13 of FIG. 2. The logic control circuit 13 comprises an input encoder and decoder 40 connected with its output to a memory 41 which in turn is connected to an output encoder and decoder 43 as well as to a distributor circuit 42 which is also connected to said input and output encoder/decoder circuit 40 and 43 as well as to a calculator 44. The distributor circuit 42 is actually a control unit which controls the information flow of the entire system by sending interrogation signals in a predetermined sequence through the input encoder/decoder 40 to the individual input components of the system such as the weight sensors 5, the operating switching 8, the main input control panel 14, and the position report element 20. The sequence control provides a sufficient time space between adjacent interrogation signals during which the response signals may be processed through the input encoder/decoder 40 in the control circuit 42, whereupon the logic results of such signal processing or rather the measured values are supplied to the output encoder/decoder 43 which in turn supplies the signals to the motor control 16, the automatic lashing devices 17, and the indicator unit 15.

The main purpose of the memory 41 is to store the information regarding the pallet or container weights, regarding the operated actuating switches 8 and regarding the type of operation supplied through the main input control panel 14. The weight, for example, must be ascertained for any particular container from six individual weight sensors 5 located under the ball bearing mat 2. The individual weight components are then added to provide the weight information for each individual container or pallet. The control circuit 42 controls the logic sequence of the calculating operations. The calculator 44 performs the calculating operations in accordance with the sequence instructions from the control circuit 42. This calculation involves the adding of the partial weight components to ascertain the weight of a container or pallet and also the addition of the container or pallet weights to obtain the total weight. Further, the calculator 44 may compare the added up weight values with predetermined maximum values in order to provide a warning signal when such maximum values are exceeded, either for any particular weight position 7 or for the total weight.

FIG. 6 shows a block circuit diagram of a freight position report unit 20 also shown in FIG. 2 and comprising a light source 45, optical means 46, and a light sensitive member 47 such as a photocell, the output of which is connected to an encoder/decoder 48 which in turn is connected with its output to a low pass filter and high pass filter 49. A power supply 50 energizes the light sensor 47 as well as the encoder/decoder 48. The light source 45, optical means 46 and the photocell 47 constitute a light barrier which is interrupted when a container or the like is placed in position in any one of the respective freight positions or stalls 7. The signal resulting from the interruption of the light barrier is provided at the output of the encoder/decoder 48 and is interrogated by the control circuit 42 through the filter means 49. The encoder/decoder designates the respective freight position 7a, 7b and so forth. The low pass filter portion of the filter means 49 pass the operating voltage coming through the coaxial cable 51 to the power supply 50 which acts as a stabilizing member providing a stabilized operating voltage to the electronic components 47, 48. Rather than interrupting a light barrier, it is also possible to reflect a light signal when a container or the like occupies a freight position 7a, 7b, and so forth. The operation would be the same.

FIG. 7 illustrates in block form further details of the display unit 15 shown in FIG. 2. The display unit 15 comprises a display field 53 for each freight position or stall 7a, 7b and so forth. Thus, the display field shows the weight of the freight in each occupied freight position. The control logic circuit 13 provides the correlation of the weight information and the respective freight position. The display unit 15 further comprises a display field 54 for the total weight and an overload indicator 55 which may provide an optical and/or acoustical overloading warning signal. Thus, it is possible according to the invention to avoid overloading the floor structure of the freight compartment in an aircraft by more evenly distributing the freight containers rather than bunching many heavy containers in one area.

The just described indicator or display fields 53, 54, and 55 receive their control signals through a code converter 52 which in turn is connected to the control logic circuit 13. The individual display fields, preferably comprise light emitting diode components each having seven elements. The code converter 52 has two purposes. First, it correlates the signals coming from the control logic circuit 13 to the individual display fields in accordance with the corresponding addresses. Further, the code converter 52 processes the digital signals into a form suitable for display. The individual fields 53 are arranged in such a manner as to represent a floor plan of the freight space, whereby each individual display field 53 symbolizes the corresponding freight location or stall 7a, 7b, and so forth. The correlation of the weight values to the individual freight locations is accomplished by the control logic circuit 13 in accordance with the loading program as described above. Instead of the digital display of the weights, it is also possible to provide an analog display as is known in the art. The analog display could be combined with a fixed maximum value display whereby the approximation of the measured value relative to the predetermined maximum value could be shown in an especially graphic manner.

The above described system is also suitable for the ascertaining of the passenger weight, whereby the platform 2' would be installed, as mentioned, as a passenger door threshold. Again, the individual weight representing signals would be supplied to the control logic circuit 13 which would be adapted to handle the maximum number of individual weight components according to the number of passengers permitted for any particular type of airplane. In this system the hand luggage would also be subject to weighing and the total weight would also be added up by a calculator for display on a display field conveniently positioned for evaluation by the pilot, for example.

It would also be possible to arrange the weight sensors in each individual passenger seat. Due to the above described digital interrogation of the various weight sensors, it is possible to contact all weight sensors in parallel so that each seat requires merely a simple coaxial plug.

The present system may also be used for calculating or ascertaining the center of gravity of the aircraft on the basis of the weight values ascertained by the individual weight sensors. Additional data may be supplied through the main control panel 14. Such additional data would relate to the center of gravity of the empty aircraft and to information regarding the fuel content of the various fuel containers. Again, the display could be provided in such a position as to conveniently supply the information to the flight personnel.

FIG. 8 illustrates a possible embodiment for the control switches 8 shown in FIGS. 1 and 2. A pressure sensitive synthetic material conductor 56 is operatively positioned between two metal plates 57 and two insulating plates 58 in a housing 60 covered by a cover plate 59. The housing 60 includes a compartment in which the electronic circuit components 61 are arranged to receive the signal caused by pressure on the cover plate 59. The output of the electronic circuit 61 is connected to a coaxial plug 62. Thus, the structure of these switches is similar to that of the weight sensors described above with reference to FIG. 3. The sensor electronic circuit 61 is constructed in the same manner as described above with reference to FIG. 4. As in FIG. 4, the synthetic material conductor 56 forms part of a bridge circuit, the analog output signal of which is supplied to an analog-to-digital converter providing a digital signal corresponding to the finger pressure exerted by an operator on the plate 59. Thus, the control signal supplied to the logic circuit 13 is proportional to the pressure and the control signal supplied in turn to the motor control 16 is also pressure proportional, whereby the motors 3', 4' may be operated with an r.p.m. which is proportional to the finger pressure of the operator. Any conventional proportional control means for electric motors may be used for the present purpose. Due to the proportional control it is possible to adapt the loading and unloading to the instantaneously prevailing conditions, whereby the maximum r.p.m. would be above the fixed r.p.m. which was customary heretofore. This feature of the invention has the advantage that it helps reducing the danger of accidents because the operator has now control over the travelling speed of the freight containers or pallets and if the conditions permit, he may increase the loading speed. Another advantage of the control sensors illustrated in FIG. 8 is seen in that they may be constructed in an elongated strip form thereby facilitating their reachability as well as their operability.

The described transmission of the signals throughout the entire system by means of a digital interrogation and the simultaneous transmission of the power supply through the same conductor is also possible without the use of a carrier freqency. Thus, the digital signals may be superimposed on the supply voltage. The filter means for such superposition and the subsequent separation of the information carrying signals from the supply voltage are well known in the art.

Further advantages of the invention are seen in that the installation of the system in the aircraft itself makes the flight planning independent of the availability of scale equipment on the ground. Another advantage is seen in the fact that the individual and total weights may be ascertained with high accuracy and so may the determination of the center of gravity of the loaded aircraft. Further, the present system itself has a negligibly small weight which is particularly due to the fact that the electrical wiring for the present system may be minimized by utilizing the wiring for multiple purposes. As mentioned, the construction of the operating switches as shown in FIG. 8 simplifies the operation of the system and reduces accidents.

FIG. 9 shows a possible embodiment of the control logic circuit 13. According to FIG. 5 this circuit 13 comprises the memory 41, the control circuit 42, the calculator 44, as well as the encoders/decoders 40 and 43 at the input or output, respectively. So far as the internal circuit is concerned, the control circuit 42 and the calculator 44 are identical. The circuit of FIG. 9 is based upon the microprocessor module SAB 8085 and the eight bit input/output module SAB 8212, both produced by SIEMENS AG, Munich, Germany. The module SAB 8085, apart from the pure calculating logic, is also provided with means for the generation of the clock pulse. These means comprise a quartz-controlled clock generator as well as a driver stage and a system control and bus driver module for the data bus. The encoders/decoders 40 and 43 may be dispensed with when the coding employed within the control logic circuit is identical with the coding employed within the entire system. A possible embodiment of the encoders/decoders 40 and 43 is exemplified in the following.

FIG. 11 shows the main control panel 14 including a keyboard corresponding to the input and output functions. The keyboard used here operates e.g. on the basis of the ASC II coding. This is a conventional telegram code. Such keyboards are commonly known and are, by way of example, also produced by DATAMEGA, Germany.

The block circuit of the indicator device 15 is illustrated in FIG. 7 and further details are shown in FIG. 10. According to FIG. 7 the indicator unit comprises essentially the code converter 52 and the weight displays 53 to 55. The displays are formed, for instance, by 7-element liqht diode modules HA 1143, manufactured by said SIEMENS AG. By way of example, the module 9368, likewise produced by SIEMENS AG, may be employed as code converter 52.

The motor control 16 shown in FIG. 2 is based upon the employment of controllable semiconductors, e.g., thyristors supplying the motor with drive energy in the form of pulses having a constant frequency and a variable pulse duration. The set pulse duration then determines the number of revolutions of the motor. Motor controls of this kind are known in the art.

The pressure sensitive plastics conductors 23 in FIG. 3 and 56 in FIG. 8 does, by way of example, comprise the material "DYNACON", produced by DYNOCON INDUSTRIES, Leona, N.J., U.S.A. The electrical conductivity of this material changes within a wide range in linear dependence of a compressive force exerted thereupon.

The electronic sensor means 26, 61 as shown, for example, are modular elements well known in electronic engineering. It is the principal object of this circuit to convert the analog signal coming from the bridge circuit into a digital signal. This operation is carried out by the A/D converter 33 which may, for instance, be embodied by the module AD 363 produced by ANALOG DEVICES. This module supplies a 12 bit output signal and is shown in FIG. 12. FIG. 13 illustrates an input or output encoder/decoder. It is possible, by way of example, to construct these circuits by the appropriate interconnection of several SAB 8255 modules, produced by SIEMENS AG. The encoding and decoding processes are carried out by this circuit. The input or output routes are separated within this circuit.
FIG. 14 shows the wiring diagram of the memory 41 provided in the control logic circuit 13. The memory 41 may, by way of example, be constructed of the following modules produced by SIEMENS AG:

SAB 8708 REPROM modules;

SAB 8111 RAM modules and

5101 CMOS-RAM modules.

The REPROM modules serve, in this case, for the reception of the preset calculating program, e.g., for the weight determination, whereas the RAM modules serve as data memory.
Although the invention has been described with reference to specific example embodiments, it is to be understood, that it is intended to cover all modifications and equivalents within the scope of the appended claims.

Control signal transmitting apparatus, particularly for aircraft

Abstract

A control system for controlling, for example, the operation of an aircraft or any other system requiring a flow of data back and forth between controlling and controlled units of the system, comprises a passive, multiply intermeshed conductor network (20, 24) of light conductors (11, 12). This network transmits control signals in the form of digital light signals from a control signal source, such as a control stick (9) in the cockpit of an aircraft or spacecraft, to respective controlled servo-units (14). The transmission system includes signal processors (10) including mixers (15) and information devices (16, 17, 18) interposed between the control signal source and the network (24) which is connected to the addressable controlled units, e.g., servo-units. The system is powered by a power supply device comprising several energy sources which may be switched on selectively as required. Such energy sources include the propulsion plant, for example, of an aircraft, an auxiliary turbine (112), a slip wind turbine (120) and an electric battery (128). Each energy source is connected to a measuring and switching unit (106, 115, 124, 131) through redundant transmission units (110) three of which are connected in parallel to one another and to the network (24). The transmission units (110) are further connected through the network (24) to a testing device (135) for monitoring and controlling the connected units or components.

Foreign Application Priority Data

References Cited [Referenced By]

U.S. Patent Documents

Other References

Primary Examiner: Martin; John C.
Assistant Examiner: Coles; Edward L.
Attorney, Agent or Firm: Fasse; W. G., Kane, Jr.; D. H.

Claims

What is claimed is:

1. In a system for transmitting control signals from a control source providing controlling signals to controlled units through signal light conductor network means operatively interconnecting said control source and said controlled units, wherein a number of light conductors form redundant connection paths between said control source and said controlled units, the improvement comprising a first plurality of longitudinal light conductors and a further plurality of cross light conductors repeatedly intermeshing said longitudinal light conductors for forming said light conductor network means with a multitude of passive closed circuit paths intermeshed with one another so that controlling signals can pass from said control source to a controlled unit even if some of these circuit paths should fail, said control source comprising means for producing said controlling signals in the form of digital light signals, signal processor means (10) including signal mixing means (15) and information processing means (16, 17, 18) operatively connected to said light conductor network means for addressing and actuating said controlled units.

2. The system of claim 1, wherein said controlled units comprise controlled surfaces (1, 2, 3, 4, 5) and servo-units operatively connected to said controlled surfaces and to said signal conductor network means, said servo-units (14) comprising intelligent memories (87) and processing units (8) for controlling and actuating said controlled surfaces.

3. The system of claim 1, wherein said controlled units comprise servo-units including position sensing and transducing means (78), and addressing means operatively connected to said position sensing and transducing means for providing a positional signal representing an instantaneous position of a controlled member.

4. The system of claim 1, wherein said signal conductor network means comprise a first network (20) of multiply intermeshed light conductors operatively interposed between said control source (9) and said mixing means of said signal processor means (10), and a second network (24) of multiply intermeshed light conductors operatively interposed between said signal processor means (10) and said controlled units (14).

5. The system of claim 1, wherein said control source (9) comprise a movable component, optronic means for sensing an instantaneous position, said optronic means comprising a movable member (29) and a stationary member (25a) arranged relative to the movable member to form a gap between the members, light emitting means operatively arranged on one of said members (30) for emitting a light signal, and light sensing means (26) arranged on the other of said members and for receiving a light signal emitted by said light emitting means, whereby the produced light signal represents the instantaneous position of said movable component of said control source.

6. The system of claim 1, wherein said control source (9) comprises electrical simulator means (37) including an addressable force or power simulator (35) having an electric motor (38) with a stator and with a rotor including a shaft, said control source further comprising a movable control stick and stationary mounting means for mounting said control stick, and stator being rigidly connected to said control stick mounting means, said shaft being rigidly connected to said control stick.

7. The system of claim 1, further comprising at least one display and operating device (92) including an image display screen (95) and an operating keyboard (95a), said device (92) being operatively connected to said mixing means through said light conductor network.

8. The system of claim 7, further comprising dialog means (100) operatively connected to said display and operating device (92), said analog means comprising a first section (101) for analyzing speech and a second section (102) for synthesizing speech.

9. The system of claim 1, wherein each of said information processing means comprise at least one memory (56) for storing information data, processor means (53) for processing information data, encoder means for encoding information representing signals, modulator means for modulating said signals, demodulating means for demodulating modulated signals, decoder means for decoding encoded signals, and a receiver for receiving information bearing signals.

10. The system of claim 4, wherein said light conductors of said first network (20) and said light conductors of said second network are provided in triplicate sets operatively connected in parallel to one another, said signal processor means including said signal mixing means and said information processing means also being provided in triplicate and connected in parallel to one another.

11. The system of claim 1, further comprising redundant power supply means (8, 112, 120, 128) operatively connected to said conductor means, said power supply means comprising measuring and switching means (106, 115, 124, 131), triplicate transmission means (110) connected in parallel for operatively connecting said measuring and switching means (106, 115, 124, 131) to said network means, and testing means (135) operatively connected to said network means and thus to said measuring and switching means.

12. The system of claim 11, wherein said power supply means comprise an aircraft propulsion plant (8), an auxiliary turbine (112), a slip wind turbine (120) and an electric battery (128).

13. The system of claim 10 or 11, wherein each of said transmission means comprises an encoder (153), a decoder (156), means (160) interconnecting said encoder and decoder, transmitter means (154) connected to said encoder means, and receiver means connected to said decoder means.

14. the system of claim 11, wherein said measuring and switching means (106, 115, 124, 131) comprise sensor means (158) for sensing an operating status or condition of a controlled unit, analog-to-digital converter means (152) operatively connected to said sensor means for converting a status representing analog signal into a digital signal, said measuring and swithcing means further comprising switching members (157, 159) connected to said transmission means (110) and to a controlled unit for switching off such controlled unit in response to malfunction of the controlled unit, whereby the measuring and switching means cooperate with the transmission means (110).

15. the system of claim 11, wherein said testing means (135) comprise three optronic information handling or processing means (147, 148, 149) operatively connected to said network means for receiving and transmitting information from and to the network means, three data processors (137, 138, 139) operatively connected to the respective information processing means for receiving and transmitting data, each of said data processors having its own memory means (140, 141, 142) for storing data therein, and two micro-processor voter means (143, 144) operatively connected to each of said three data processors for monitoring and sequencing the operation of said three data processors.

16. The system of claim 15, wherein said testing means further comprise external memory means (150) for storing maintenance data, said external memory means being operatively connected to any one of said three data processors.

17. The system of claim 15, further comprising at least one network analysing means (163) operatively connectable to said testing means for analysing the operational status of said network means.

18. The system of claim 15, comprising three network analysing means (163) each of which is operatively connected to its respective data processor (137, 138, 139) of said testing means.

19. The system of claim 17 or 18, wherein said network analysing means comprise operating means capable of handling colored analysing light signals the color of which differs from that of any colored operating light signal.

20. The system of claim 11, wherein said testing unit (135) is operatively connected to the system for monitoring and controlling any component of the system.

21. The system of claims 1 or 4, wherein said light conductors comprise fiber optical conductors which are made of a colored material.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention relates to corresponding German Patent applications: No. P 30 32 918.1, filed on Sept. 2, l980 in the Federal Republic of Germany; and No. P 31 11 722.8, filed on Mar. 25, 1981 in the Federal Republic of Germany. The priority of said German filing dates is hereby expressly claimed.

BACKGROUND OF THE INVENTION

The invention relates to a control signal transmitting apparatus especially for aircraft. Such control signals are to be transmitted to the control surfaces, for example, the flaps of the elevator assembly, the rudder assembly, and so forth. The transmission is to be accomplished by a passive conductor system.

It is generally known that control signals in an aircraft are transmitted in response to control movements made by the pilot, for example to control the rudder, by mechanical means such as cable pulls, linking rods, rotational shafts, or combinations of such mechanical means. Depending on the type of application, these devices are supplemented by hydraulic or electrical drive means. It is further known in connection with large volume aircraft to employ servo-control systems. Due to the mechanical coupling means interposed between certain rudders in such control systems the operational patterns are positively or rigidly determined. For example, the following operational patterns are so determined: operation of the elevator assembly takes place always symmetrically, operation of the ailerons takes place always in a non-sysmmetrical manner, operation of the landing flaps or air brake flaps always takes place symmetrically.

These fixed operational patterns have the disadvantage that, for example, upon failure of a certain rudder, the remaining still operational rudder might possibly not be available for use in re-establishing the maneuverability. If military considerations are taken into account the above mentioned mechanical control systems have a further disadvantage resulting from their vulnerability. Thus, for these purposes electrical servo-control systems have been used in which the transmission of control signals takes place through passive conductors such as coaxial cables. In such a system it is possible to provide the individual operational circuits including the cables leading to the individual adjustment members in a redundant manner, for example in quadruplicate. Thus, such an operational circuit remains, for example, still operational even if three of the respective cables have failed, for example, as a result of combat action. However, the provision of redundant signal transmitting circuit means has, among others, the following weak points. Such systems are sensitive to electro-magnetic disturbing fields such as lightning impact, short circuits and the like. An intermeshed cable network cannot be realized without active elements at the nodal points of the network due to transit time effects and reflection effects. Further, due to the just mentioned effects, the wiring may be carried out in practice only in the form of function related wiring strands. This means that, for example, in a quadruplicate redundancy systemn four cables are required for each adjustment member to be controlled. Additionally, this type of wiring results in a substantial cable weight if cables with a low damping coefficient are used.

According to the magazine "Electronik Praxis" (Electronic Practice), Vol. 11, pg. 34, 1979, it is known to use light conductors for the assembly of data bus systems, for example, on board ships or aircraft or for controlling industrial processes. In a narrower sense the term "data bus" means a conductor for transmitting or relaying of information to which all subscribers are connected. According to the above article, such systems may be constructed as so-called radial or star-bus or as a T-bus. In a radial or star-bus system all connecting conductors converge in a so-called star-coupling member. In a T-bus system each subscriber is connected to the data-bus by a T-coupling member. The light conductor technique has substantial advantages with regard to its use in the control systems of an aircraft, for example, with regard to the weight and reliability. Nevertheless, the radial or star-bus concept as well as the T-bus concept have the disadvantage that each subscriber or rather, each controlled member is connected to the remainder of the system through but one conductor. It follows, that upon failure of such single conductor the functions of the respective subscriber or controlled member must also fail. In connection with the control of an aircraft this would mean that upon failure of a corresponding conductor, for example, due to a localized damage as a result of the failure of other components, possibly a vital control function could be eliminated.

OBJECTS OF THE INVENTION

In view of the above it is the aim of the invention to achieve the following objects singly or in combination:

to provide an arrangement, especially suitable for the control of aircraft, for transmitting of control signals without any malfunctions due to transit time effects, reflections, and electro-magnetic disturbing fields;

to provide a control signal transmission system which operates passively as an intermeshed conductor network which makes it possible to perform new, preprogrammed control steps or control functions in response to the failure of control elements;

to provide a power supply system the reliability of which is compatible with the reliability of the other elements in the control system to be powered by the power supply system;

to provide a light conductor system for the control of an aircraft which has a high degree of freedom against interference from any possible extraneous light influences; and

to provide a control system especially suitable for the control of aircrafts which has a high reliability factor.

SUMMARY OF THE INVENTION

According to the invention there is provided a system for the transmission of control signals especially to the control surfaces in an aircraft by a passive conductor system which is characterized by a conductor system comprising a network including repeatedly intermeshed light conductors. The system further includes control members for producing of control instructions in the form of digital light signals. The control members are connected to the light conductor network for transmitting the control instruction signals through signal processors including signal mixers and information systems. Servo-mechanisms are connected to the outputs of the light conductor intermeshed network, whereby the servo-mechanisms are addressable and controllable for effecting the respective control function.

By means of the system according to the invention a substantially increased safety factor has been realized as compared to mechanical, hydraulical, or electrical systems or any combination of such prior art systems. Another advantage of the invention is seen in that it is now possible for the controlled surfaces to perform new types of combinations of excursions or deflections in certain dangerous situations. Thus, even if a rudder should fail, the maneuverability of the aircraft is retained.

According to the invention the present control system is provided with its own energy supply or power supply which comprises a measuring and switching unit which in turn is connected through three transmission units arranged in parallel to the intermeshed network and through the network with a testing unit. This feature of the invention has the advantage that the power supply to the control system has been greatlyimproved as far as the degree of reliability is concerned. Thus, the degree of reliability of the power supply system corresponds to the degree of reliability of the remainder of the system which is powered by the power supply according to the invention.

Further advantages are achieved by the features of the dependent claims according to the invention.

BRIEF FIGURE DESCRIPTION

In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein:

FIG. 1 is a somewhat schematic yet perspective overview of a system according to the invention as installed in an aircraft;

FIG. 2 illustrates a block circuit arrangement of a main control circuit;

FIG. 3 illustrates an optical system for sensing the instantaneous position of a control member such as the control stick in an aircraft;

FIG. 4 is a block cicuit diagram of a power simulator;

FIG. 5 is a circuit arrangement of a mixing unit;

FIG. 6 is block circuit arrangement of an optical-electronical (optronical) informatin system;

FIG. 7 illustrates a block circuit diagram of a servo-unit operating as a controlled unit;

FIG. 8 is a display and operating unit including a control keyboard;

FIG. 9 shows a block circuit diagram of a dialog device;

FIG. 10 is a circuit diagram of the power supply system according to the invention;

FIG. 11 shows a block circuit diagram of the internal components of a testing circuit employed in FIG. 10;

FIG. 12 is a block circuit diagram of the internal components of a measuring and switching unit and including a transmission unit employed in FIG. 10;

FIG. 13 illustrates a network analyzer including a portion of a network; and

FIG. 14 shows a block circuit diagram of the internal components of a network analyzer as illustrated in FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE OF THE INVENTION

FIG. 1 shows an over-view of the arrangement for transmitting of control signals in an aircraft F. The aicraft F comprises the conventional control surfaces including two elevator assemblies 1, 1', a rudder assembly 2, two slow speed ailerons or wing flaps 3, 3', two high speed ailerons or wing flaps 4, 4', landing flaps or air brakes 5, 5' leading edge flaps 6, 6' and a tail plane or horizontal stabilizer 7. The aircraft further comprises among other conventional components the propulsion plants or engines 8, 8', as well as the control organs 9, whereby the schematic illustration indicates the control sticks 9a', 9a" and the foot pedals not shown forming a control input source.

As also shown in FIG. 2, the conductor system for transmitting the control signals comprises primarily several signal processors 10 and repeatedly intermeshed networks 20, 24 comprising light conductors including longitudinal conductors 11 and cross conductors 12 forming a multitude of passive closed circuit paths intermeshed with one another so that controlling signals can pass from the control organs 9 to a controlled unit even if some of the circuit paths should fail. The light conductor network 20 is operatively connected between the control input source and the signal processors 10. The light conductor network 24 is operatively connected between the processors 10 and the addressable servo-units 14 forming controlled units. The nodal points 13 comprise branching means of conventional construction, for example, in the form of radial coupling members or T-coupling members for forming said repeatedly or multiply intermeshed network. The control members 9 are constructed in such a manner that they provide a digital light signal corresponding to the control instruction. The servo-units 14 connected to the periphery of the network 24 comprise means for converting the incoming light signals into a control motion. Additionally, the servo-units 14 comprise means for sensing the instantaneous position, for example, of a rudder, and for producing a corresponding light signal which is supplied to the longitudinal conductors 11.

The data transmission between the signal processors 10 and the peripheral devices such as the servo-units 14 connected to the longitudinal light conductors 11 is performed in a cyclic manner. Stated differently, the signal processors 10 supply information signals, for example to the servo-units 14 which signals are addressed in accordance with a fixed interrogation sequence. The servo-units 14 in turn respond to these signals in accordance with addressed information signals. The data traffic that takes place in this connection is defined in the form of so-called telegrams having a fixed word length.

These telegrams are modulated by means of a digital frequency modulation onto a carrier frequency, whereby the light signal exhibits an amplitude modulation corresponding to the carrier frequency. This feature assures a very large safety against malfunctions that may otherwise be caused by any possible extraneous stray light input. Due to the intermeshing it is assured that a signal may reach the addressed servo-units 14 from the signal processors 10 via numerous conductor connections whereby the reliability of the system is further increased. The illustrated system has a triple redundancy which is achieved by arranging the longitudinal conductors 3 and the respective cross conductors 12 in triplicate for each rudder, control surface or the like and by providing three servo-units 14 accordingly. Thus, three of these conductors 11, 12 are arranged in the fuselage, in each wing, and in the tail units. The signal processors 10 comprise the main control circuit for the entire arrangement. These signal processors 10 are also provided in triplicate for increasing the reliability.

FIG. 2 shows a circuit arrangement of one of the signal processors 10 comprising primarily or substantially a mixer 15 and three information handling means 16, 17, 18. The mixer 15 is connected by means of triple light conductors 19 to an intermeshed input network 20 comprising light conductors. Each of the triple ouputs of the mixers 15 is connected with its respective information unit 16, 17, or 18. Each unit 16 to 18 comprises further three connecting light conductors 16a, 17a, and 18a. These connecting light conductors are respectively connected to the network 24 comprising the longitudinal conductors 11 and the cross conductors 12.

The mixer 15 serves for t