PLATOONING CONTROL VIA ACCURATE SYNCHRONIZATION

• US 20170227972A1
• Filed: 04/21/2017
• Published: 08/10/2017
• Est. Priority Date: 10/21/2014
• Status: Active Grant

• Current Assignee: Road Trains LLC
• Original Assignee: Road Trains LLC
• Inventors: Sabau, Serban
• Granted Patent: US 10,488,869 B2
• Time in Patent Office: Days
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G05D 1/0027 involving a plurality of vehicles, e.g. fleet or convoy travelling fleet control of land vehicles from a control room G05D1/0297; traffic control systems for road vehicles G08G1/00; for marine craft G08G3/00; for aircraft G08G5/00
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0291 Fleet control monitoring fleets in traffic control systems for road vehicles G08G1/127, G08G1/127
• CPC Class Codes: G05D 1/0293 Convoy travelling
• CPC Class Codes: G05D 1/0295 by at least one leading vehicle of the fleet
• CPC Class Codes: G08G 1/22 Platooning, i.e. convoy of communicating vehicles

Abstract

Various embodiments provide for platooning control via accurate synchronization that will not result in string instability. Some embodiments provide a distributed control scheme for platoon motion control that provides a decentralized implementation of the leader information controller. These control techniques are able to manage the performance of the string of vehicles by maintaining a desired spacing distance between any two successive vehicles in the presence of communications induced delays. In order to regulate the spacing between a vehicle and its predecessor in the string, every vehicle (with the exception of the leader vehicle) uses the relative distance from itself to its predecessor (e.g., as measured using a laser ranging sensor) and a control signal of the predecessor (e.g., received via a wireless link). Various embodiments are capable of dealing with non-homogeneous strings of vehicles and non identical controllers for each vehicle in the string.

Claims

1. A method for operating a vehicle within a string of platooning vehicles, the method comprising:

receiving, via a wireless communications link, a control signal of a predecessor vehicle,

wherein the predecessor vehicle immediately precedes the vehicle in the string of platooning vehicles;

wherein each vehicle in the string of platooning vehicles has access to a synchronized clock; and

wherein the control signal from the predecessor vehicle has been stamped with a first time base from the synchronized clock;

determining a distance between the vehicle and the predecessor vehicle,

wherein the distance between the vehicle and the predecessor vehicle is stamped with a second time base from the synchronized clock;

generating a synchronized distance and control signal based on first time stamp and the second time stamp; and

generating a control action to maintain a desired distance between the vehicle and the predecessor vehicle based at least in part on the synchronized distance and control signal.

2. The method of claim 1, wherein the distance is determined using lidar or radar.

3. The method of claim 1, wherein the wireless communication link includes an optical link or a personal area network.

4. The method of claim 1, wherein the desired distance between the vehicle and the predecessor vehicle is proportional to a speed of the vehicle.

5. The method of claim 1, further comprising:

identifying vehicle type of the predecessor vehicle; and

retrieving, from a memory store, a dynamical model of the predecessor vehicle,

wherein generating the control action for the vehicle is also based at least in part on the dynamical model of the predecessor vehicle.

6. The method of claim 1, further comprising:

associating a third time base from the synchronized clock with the control action for the vehicle;

transmitting, via a second wireless link, the control action for the vehicle to a follower vehicle in the string of platooning vehicles.

7. The method of claim 1, wherein the synchronized clock is part of a global positioning system.

8. A vehicle comprising:

a throttling and braking system;

a communications system with a receiver to receive communications from a predecessor vehicle and a transmitter to transmit signals to a follower vehicle,

wherein the communications from the predecessor vehicle include control signals from the predecessor vehicle that are each labeled with time stamps indicating the time of execution;

a distance measuring system to repeatedly measure distances between the vehicle and the predecessor vehicle over time,

wherein the distances measured by the distance measuring system are stored with time stamps indicating the time of measurement;

a synchronization module to synchronize the distances measured by the distance measuring system and the control signals based using the time stamps; and

a controller to generate a control action to be implemented by the throttling and braking system to maintain a desired distance behind the predecessor vehicle,

wherein the control action is based on the control signals and distances synchronized by the synchronization module.

9. The vehicle of claim 8, wherein the desired distance is proportional to a speed of the vehicle.

10. The vehicle of claim 8, wherein distance measurement system includes lidar or radar.

11. The vehicle of claim 8, wherein the communication system includes an optical link or a personal area network.

12. The vehicle of claim 8, further comprising a global positioning system with a synchronous clock

13. The vehicle of claim 8, wherein the communication system retrieves, from a remote server, a dynamical model of the predecessor vehicle, and

wherein the communications from the predecessor vehicle includes a vehicle identifier;

and

wherein generating the control action for the vehicle is also based at least in part on the dynamical model of the predecessor vehicle retrieved from the remote server using the vehicle identifier.

14. The vehicle of claim 8, further comprising:

a memory having stored thereon model dynamics for multiple vehicles;

wherein the controller retrieves, from the memory, a dynamical model of the predecessor vehicle,

wherein the communications from the predecessor vehicle includes an identification of the vehicle type of the predecessor vehicle; and

wherein generating the control action for the vehicle is also based at least in part on the dynamical model of the predecessor vehicle retrieved from the memory store using the identification.

15. The vehicle of claim 8, further comprising an optical target plate.

16. The vehicle of claim 8, wherein the communication system includes a cellular system that is capable of transferring data regarding the vehicle to a monitoring station.

17. A computer-readable storage medium, excluding transitory signals, having stored thereon a set of instructions that may be executed by one or more processors to a vehicle to:

receive a control signal of a predecessor vehicle that immediately precedes a current vehicle in a string of platooning vehicles;

wherein the control signal from the predecessor vehicle has been stamped with a first time base;

determine a distance between the current vehicle and the predecessor vehicle,

wherein the distance between the current vehicle and the predecessor vehicle is stamped with a second time base;

generate a synchronized distance and control signal based on first time stamp and the second time stamp; and

generate a control action for the current vehicle to maintain a desired distance from the predecessor vehicle based at least in part on the synchronized distance and control signal.

18. The computer-readable storage medium of claim 17, wherein the desired distance between the vehicle and the predecessor vehicle is proportional to a speed of the vehicle.

19. The computer-readable storage medium of claim 17, wherein the set of instruction when executed by the one or more processor further cause the vehicle to:

identify a vehicle type of the predecessor vehicle; and

retrieve, from a local or cloud-based memory store, a dynamical model of the predecessor vehicle,

wherein generating the control action for the vehicle is based at least in part on the dynamical model of the predecessor vehicle.

20. The computer-readable storage medium of claim 17, wherein the set of instruction when executed by the one or more processor further causes the vehicle to:

associate a third time base with the control action for the vehicle;

transmit, via a second wireless link, the control action for the vehicle to a follower vehicle in the string of platooning vehicles.

21. The computer-readable storage medium of claim 17, wherein the control signal is received via a personal area network.

22. A method for operating a vehicle within a string of platooning vehicles, the method comprising:

receiving, via a wireless communications link, a control signal of a predecessor vehicle,

wherein the predecessor vehicle immediately precedes the vehicle in the string of platooning vehicles;

determining a distance between the vehicle and the predecessor vehicle,

generating a control action to maintain a desired distance between the vehicle and the predecessor vehicle based at least in part on the distance, on the control signal and on the dynamical model of the predecessor vehicle.

23. The method of claim 22, wherein the distance is determined using lidar or radar.

24. The method of claim 22, wherein the wireless communication link includes an optical link or a personal area network.

25. The method of claim 22, wherein the dynamical model of the predecessor vehicle includes the mass of the predecessor vehicle.

26. The method of claim 22, wherein the dynamical model of the predecessor includes at least in part specifications of the drive train of the predecessor vehicle.

27. The method of claim 22, wherein an electronic filter based at least in part on the dynamical model of the predecessor is used for the control signal.

28. A vehicle comprising:

a throttling and braking system;

a communications system with a receiver to receive communications from a predecessor vehicle and a transmitter to transmit signals to a follower vehicle,

wherein the communications from the predecessor vehicle include control signals from the predecessor vehicle,

a distance measuring system to repeatedly measure distances between the vehicle and the predecessor vehicle over time,

a controller to generate a control action to be implemented by the throttling and braking system to maintain a desired distance behind the predecessor vehicle,

wherein the control action is based at least in part on the control signals, distance and on the dynamical model of the predecessor vehicle.

29. The vehicle of claim 28, wherein distance measurement system includes lidar or radar.

30. The vehicle of claim 28, wherein the communication system includes an optical link or a personal area network.

31. The vehicle of claim 28, wherein the dynamical model of the predecessor vehicle includes the mass of the predecessor vehicle.

32. The vehicle of claim 28, wherein the dynamical model of the predecessor includes at least in part specifications of the drive train of the predecessor vehicle.

33. The vehicle of claim 28, wherein an electronic filter based at least in part on the dynamical model of the predecessor is used for the control signals.

34. A computer-readable storage medium, excluding transitory signals, having stored thereon a set of instructions that may be executed by one or more processors to a vehicle to:

receive a control signal of a predecessor vehicle that immediately precedes a current vehicle in a string of platooning vehicles;

determine a distance between the current vehicle and the predecessor vehicle, and

generate a control action for the current vehicle to maintain a desired distance from the predecessor vehicle, based at least in part on the distance, control signal and on the dynamical model of the predecessor vehicle.

35. The computer-readable storage medium of claim 34, wherein the control signal is received via an optical link or personal area network.

36. The computer-readable storage medium of claim 34, wherein the determination of the distance is performed using lidar or radar.

37. The computer-readable storage medium of claim 34, wherein the dynamical model of the predecessor vehicle includes the mass of the predecessor vehicle.

38. The computer-readable storage medium of claim 34, wherein the dynamical model of the predecessor vehicle includes at least in part specifications of the drive train of the predecessor vehicle.

39. The computer-readable storage medium of claim 34, wherein an electronic filter based at least in part on the dynamical model of the predecessor is used for the control signals.