Guide wire communication system and method

• US 4,791,570 A
• Filed: 06/11/1986
• Issued: 12/13/1988
• Est. Priority Date: 05/02/1985
• Status: Expired due to Fees

• Current Assignee: HK Systems Incorporated (KION GROUP AG)
• Original Assignee: Eaton-Kenway Incorporated
• Inventors: Madsen, David C., Sherman, Leigh E., Whatcott, Gary L., Dicks, Richard M.
• Primary Examiner(s): Chin, Gary
• Application Number:
  US06/873,032
• Time in Patent Office: 916 Days
• Field of Search: 364/424, 364/436, 180/167, 180/168, 180/169, 318/587
• US Class Current: 701/117
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: G05D 1/0297 by controlling means in a control room

Abstract

A guidance system for guiding a plurality of unmanned vehicles along guide wires. A plurality of data communication circuits are provided which form an extensive network. A traffic control computer composes a coded vehicle instruction for assigning tasks and allocates resources to said unmanned vehicles. The traffic control computer polls the status of each vehicle at varying time intervals and receives a response from said vehicle. The network connecting the computer and the communication circuits prevents reception of data transmissions from more than one vehicle at a time. Other messages are temporarily, stored. Data transmitters generate low frequency, low power signals which have a high data transmission rate. Digital data is converted at the transmitters into cosine waveforms of selected frequencies. The cosine waveforms are transposed into sine waveforms at receivers. Low impedance or high impedance characteristics are imposed upon the guide wires. A low frequency, high gain transmit antenna for each vehicle is prorated.

Claims

1. A communication system for controlling a plurality of unmanned task-performing vehicles which are respectively caused to selectively traverse guide wire means comprising;

a plurality of unmanned task-performing vehicles, each vehicle comprising a vehicle transmitter;

vehicle traffic control means comprising transmitter means and a plurality of control receivers, each said receiver being paired with an associated receiver control means in electrical communication therewith;

each receiver control means being in electrical communication with all other receiver control means;

guide wire means along which the vehicles selectively travel, the guide wire means receiving each output message from each vehicle transmitter of each vehicle traversing the guide wire means and communicating said message to one of the control receivers and receiving each control output message from the control transmitter means and communicating said received output message from the control transmitter means to one predetermined vehicle;

the vehicle traffic control means being in electrical communication with each control receiver whereby a message received by any control receiver is communicated to the vehicle traffic control means;

each receiver control means comprising means issuing a signal selectively disabling the associated receiver upon the receipt of a signal from another receiver control means by which the system is temporarily preempted for transmission of a single message between the vehicle traffic control means and one vehicle;

thereby avoiding mixing of message with resulting errors, whereby the system accommodates infinite expansion in terms of the number of vehicles and guide wires.

2. A communication system according to claim 1 wherein the vehicle traffic control means further comprises memory means for temporarily storing messages for sequential transmission between the vehicle traffic control means and predetermined control site receivers.

3. A communication system according to claim 1 wherein at least one of the control receivers further comprises memory means for temporarily storing messages communicated between the vehicle traffic control means and that at least one control site receiver, said memory means being in electrical communication with said vehicle traffic control means and said at least one control receiver.

4. A communication system according to claim 1 further comprising memory means for storing messages to be subsequently communicated between at least one of said unmanned task-performing vehicles and the vehicle traffic control means, said memory means being in electrical communication with said at least one unmanned task-performing vehicle and vehicle transmitter of said at least one unmanned task-performing vehicle.

5. A system for controlling a plurality of unmanned task-performing guide wire related vehicles by exclusive temporary allocation of guide wire length segments whereby the travel paths and tasks performed by the vehicles are strictly controlled and conflict between vehicles is avoided, the system comprising:

a plurality of unmanned task-performing vehicles, each vehicle comprising vehicle receiver means and vehicle control means;

traffic control means by which all vehicles are controlled located at at least one vehicle-remote control site, the traffic control means comprising control transmitter means;

guide wire means defining transportation paths along which the vehicles selectively travel, the guide wire means receiving messages from the control transmitter means and communicating the messages to the vehicle receiver means;

the traffic control means further comprising means which electronically identify guide wire length segments, means which electronically identify each transportation task to be performed by any vehicle, means which correlate the transportation task and guide wire length segments needed for carrying out each transportation task, means for reserving the guide wire length segments required for completion of a specific transportation task assigned to one of said vehicles, means causing the traffic control transmitter means to communicate the specific task to the vehicle receiver of said one vehicle and to allocate the reserved guide wire length segments to said one vehicle whereupon the traffic control means cause the one vehicle to perform the specific task using the reserved guide wire length segments, means preventing the specific task and reserved guide wire length segments from being performed and made available, respectively, to a second vehicle during the performance of the specific task and utilization of the reserved guide wire length segments by the said one vehicle.

6. A system according to claim 5 wherein the traffic control means further comprise control receiver means and wherein each vehicle further comprises vehicle transmitter means in communication with the control receiver means and wherein the vehicle transmitter means comprise means which (a) selectively signal the traffic control means through the control receiver means when a specific task assigned to the vehicle with which the transmitter means is associated has been completed and (b) release to the traffic control means at least substantially all of the reserved guide wire length segments for reallocation by the traffic control means.

7. A system according to claim 6 wherein the signal and release means release all of the reserved guide wire length segments except for the length segment of the guide wire means physically occupied by the vehicle at the time of the release.

8. A system according to claim 5 further comprising memory means for temporarily storing messages to be subsequently communicated between the traffic control means and at least one control receiver menas, said memory means being in electrical communication with said traffic control means and said at least one control receiver means.

9. A system according to claim 5 further comprises memory means in electrical communication with the traffic control means for temporarily storing all non-first-in-time messages to be communicated from the traffic control means.

10. A system according to claim 5 wherein at least one unmanned task-performing vehicle further comprises memory means for temporarily storing meassages to be communicated between the at least one vehicle and the traffic control means, said memory means being in electrical communication with said unmanned task-performing vehicle and vehicle transmitter means of said vehicle.

11. A polling communication system for controlling a plurality of unmanned task-performing vehicles which are respectively caused to selectively traverse at least one path defined by guide wire means comprising:

a plurality of unmanned task-performing vehicles, each vehicle comprising vehicle transmitter means, vehicle receiver means, and vehicle control means;

traffic control means comprising control receiver means and control transmitter means located at at least one control site remote from the vehicles;

guide wire means in electrical communication with the vehicle transmitter means and vehicle receiver means of each vehicle and the control receiver means and the control transmitter means, the guide wire means defining at least one path to be traversed in whole or in part by the vehicles;

the traffic control means further comprising means by which a given task and path enablements for performing said task are exclusively delegated to a single vehicle of the system, said path enablements comprising reservation of specific length segments of the path defined by said guide wire means to the single vehicle;

means by which a predetermined time to perform said task is set and means causing the single vehicle to be polled by the traffic control means at a point in time corresponding essentially to the predetermined time set.

12. A communication system according to claim 11 wherein the time setting means are in electrical communication, via the guide wire means, with the traffic control means but are vehicle-carried.

13. A communication system according to claim 11, wherein the traffic control means further comprises memory means for temporarily storing on a prioritized basis messages to be communicated between the traffic conrol means and any control receiver means, said memory means being in electrical communication with said traffic control means and said any control receiver means.

14. A communication system according to claim 11 wherein the control receiver means further comprises memory means for temporarily storing messages communicated between the traffic control means and said control receiver means, said memory means being in electrical communication with said vehicle traffic control means and said control receiver means.

15. A communication system according to claim 11 wherein at least one unmanned task-performing vehicle further comprises memory means for temporarily storing messages to be communicated between the at least one vehicle and the traffic control means, said memory means being in electrical communication with said unmanned task-performing vehicle and the vehicle transmitter means of said vehicle.

16. A method for controlling a plurality of unmanned task-performing vehicles which are respectively caused to selectively traverse guide wire means comprising the steps of:

electrically connecting control receivers and receiver control means in pairs at control sites;

electrically connecting each control receiver to guide wire means which define at least one path upon which unmanned task-performing vehicles travel;

electrically connecting the control receivers one to the others;

communicating, upon receipt at a selected control receiver of a message, to the receiver control means paired with said selected control receiver thereto and issuing a temporarily disabling signal from said selected paired receiver control means to all other receiver control means;

thereby temporarily disabling all other control receivers;

thereafter transmitting said message to a specific vehicle along the guide wire means;

whereby inclusion of an infinite number of vehicles and guide wires is accommodated and control reception is precluded during message transmissin to a vehicle.

17. A method according to claim 16 wherein the communicating step further comprises temporarily storing said message in memory.

18. A method for controlling a plurality of unmanned task-performing computer-controlled vehicles which traverse at least part of transportation paths defined by guide wire means, comprising the steps of:

identifying all length segments of guide wire means along which a plurality of unmanned task-performing vehicles selectively travel;

determining each task to be performed by any of said vehicles;

correlating said each task to be performed and the length segments available for accomplishment of said each task;

assigning to a selected single vehicle a specific task and the correlated length segments needed to accomplish the assigned specific task;

transmitting along the guide wire means to the selected single vehicle the assignment of the specific task and reserving the length segments to the selected single vehicle;

receiving said transmission from the guide wire means at receiver means carried by said single vehicle;

causing the vehicle to perform the specific assigned task using the assigned length segments on a short term basis, while preventing the assigned task from being accomplished by and the assigned length segments from being made available to a second vehicle during the performance of the assigned specific task and utilization of the assigned length segments by the selected single vehicle.

19. A method according to claim 18 further comprising notifying traffic control means through receiver means associated therewith when the task assigned to the selected vehicle has been completed;

and

releasing at least substantially all of the length segments for reallocation.

20. A method according to claim 19 wherein the releasing step comprises releasing all of the length segments except for the length segment physically occupied by the selected single vehicle at the time of the release.

21. A method according to claim 18 further comprising the step of temporarily storing in memory other control messages during the transmitting step.

22. A method for controlling a plurality of unmanned task-performing vehicles which are respectively caused to selectively transverse paths defined by guide wire means comprising the steps of:

exclusively electronically assigning, via a control center and guide wire means a specific task and exclusively allocating specific task-related length segments of guide wire means for performing said specific task to a selected single vehicle of the system;

electronically estimating the time required to perform said specific task; and

causing a task-related status of the selected single vehicle to be electronically polled essentially at a point in time corresponding to the length of the estimated time.

23. A method according to claim 22 wherein the electronically estimating step comprises electronically estimating the time expected to be required by the selected vehicle to perform said specific task and communicating said estimate to the control center.

24. A two-way communication system for controlling a plurality of unmanned task-performing vehicles comprising:

a computer control center comprising transmitter means, control means and receiver means;

a plurality of unmanned task-performing vehicles remote from the computer control center, each vehicle comprising transmitter means and receiver means;

guide wire means defining a plurality of paths which are selectively traversed by the vehicles, the guide wire means comprising means for transmitting messages to each vehicle and the computer control center;

means disabling all messages and signal transmissions and receptions from said vehicle to the computer control center when the computer control center transmitter means are transmitting a task-related message to a specific vehicle.

25. A two-way communication system according to claim 24 wherein the computer control center transmitter means transmits each message intended for a single vehicle globally to all vehicles and wherein each vehicle comprises means causing all vehicles to ignore said global message except for said single vehicle.

26. A two-way communication system according to claim 24 wherein each vehicle comprises means which inhibit the associated vehicle transmitter means except when vehicle transmission is responsive to computer control center polling of said specific vehicle.

27. A two-way communication system according to claim 26 wherein the computer control center comprises means which cause vehicles to be polled sequentially whereby the vehicles so polled to respond sequentially.

28. A two-way communication system according to claim 24 comprising disable/enable means by which the vehicle transmitter means of each vehicle are disabled when the associated vehicle receiver means are operating and by which the vehicle receiver means of each vehicle are disabled when the associated vehicle transmitter means are operating.

29. A two-way communication system according to claim 24 wherein the computer control center comprises time estimating means to estimate the length of time needed by the specific vehicle to perform each assigned task and further comprising means which poll the status of the specific vehicle at the end of said estimated length of time.

30. A two-way communication system according to claim 24 further comprising means which electronically define length segments of the guide wire means and which electronically identify and exclusively reserve to the specific vehicle all guide wire length segments needed to complete an assigned task until the assigned task is completed.

31. A two-way communication system according to claim 24 wherein said computer control center further comprises means which normally inhibit transmission of duplicate computer control center messages and means which cause a duplicate computer control center message to be transmitted only when the original message is not acknowledged by the vehicle for which it was intended.

32. A two-way communication system according to claim 29 further comprising computer control center message memory wherein messages to be transmitted to selected vehicles are stored for sequential delivery to the contrl transmitter means.