DYNAMIC GAP CONTROL FOR AUTOMATED DRIVING

• US 20180050697A1
• Filed: 05/25/2017
• Published: 02/22/2018
• Est. Priority Date: 08/22/2016
• Status: Active Grant

• Current Assignee: Peloton Technology, Inc.
• Original Assignee: Peloton Technology, Inc.
• Inventors: KUSZMAUL, James B., SCHUH, Austin B., ERLIEN, Stephen M., SWITKES, Joshua P.
• Granted Patent: US 10,369,998 B2
• Time in Patent Office: Days
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2050/0075 Automatic parameter input, automatic initialising or calibrating means
• CPC Class Codes: B60W 2300/125 Heavy duty trucks
• CPC Class Codes: B60W 2420/408 Radar; Laser, e.g. lidar
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2556/65 Data transmitted between vehicles
• CPC Class Codes: B60W 2710/09 Other types of propulsion units, e.g. fluid motors, or type not specified
• CPC Class Codes: B60W 2710/18 Braking system
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 2756/10 Involving external transmission of data to or from the vehicle
• CPC Class Codes: B60W 30/165 : Automatically following the path of a preceding lead vehicle, e.g. "electronic tow-bar"
• CPC Class Codes: B60W 40/1005 : Driving resistance
• CPC Class Codes: G01S 13/93 : for anti-collision purposes
• CPC Class Codes: G01S 13/931 : of land vehicles
• CPC Class Codes: G01S 19/13 : Receivers
• CPC Class Codes: G01S 19/14 : specially adapted for specific applications
• CPC Class Codes: G01S 2013/9316 : combined with communication equipment with other vehicles or with base stations
• CPC Class Codes: G01S 2013/93185 : Controlling the brakes
• CPC Class Codes: G01S 2013/9319 : Controlling the accelerator
• CPC Class Codes: G01S 2013/9323 : Alternative operation using light waves
• CPC Class Codes: G01S 2013/9325 : for inter-vehicle distance regulation, e.g. navigating in platoons
• 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 1/161 : Decentralised systems, e.g. inter-vehicle communication
• CPC Class Codes: G08G 1/22 : Platooning, i.e. convoy of communicating vehicles

Abstract

A variety of methods, controllers and algorithms are described for controlling a vehicle to closely follow one another safely using automatic or partially automatic control. The described control schemes are well suited for use in vehicle platooning and/or vehicle convoying applications, including truck platooning and convoying controllers. In one aspect, a power plant (such as an engine) is controlled using a control scheme arranged to attain and maintain a first target gap between the vehicles. Brakes (such as wheel brakes) are controlled in a manner configured to attain and maintain a second (shorter) target gap. Such control allows a certain degree of encroachment on the targeted gap (sometimes referred to as a gap tolerance) before the brakes are actuated. The described approaches facilitate a safe and comfortable rider experience and reduce the likelihood of the brakes being actuated unnecessarily.

Claims

1. A method of controlling a first vehicle to at least partially automatically maintain separation from a second vehicle while driving, the first vehicle having a power plant and brakes, the method comprising:

automatically controlling an output of the power plant during driving in accordance with a power plant output control scheme arranged to attain and maintain a first target gap between the first and the second vehicles; and

automatically controlling the brakes during driving in accordance with a braking control scheme arranged to attain and maintain a second target gap during first selected operating conditions, the second target gap being shorter than the first target gap.

2. A method as recited in claim 1 wherein:

the difference between the first and second target gaps is a gap tolerance; and

automatically controlling the brakes to maintain the second gap during the first selected operating conditions causes braking requests to be generated during the first selected operating conditions only when the first vehicle has encroached upon the second vehicle by at least the gap tolerance relative to a targeted separation distance between the first and second vehicles dictated by the first control scheme at a current operational state.

3. A method as recited in claim 2 wherein the gap tolerance varies at least in part based on a current actual gap between the first and second vehicles.

4. A method as recited in claim 1 wherein in at least some circumstances, when the first vehicle receives an indication that the second vehicle is applying its brakes, the braking control is switched to automatically control the brakes in a manner arranged to attain and maintain the first gap rather than the second target gap.

5. A method as recited in claim 1 wherein in at least some circumstances, when the first vehicle receives an indication that the second vehicle is applying its brakes, the braking control is switched to automatically control the brakes for the trailing vehicle in a manner arranged to attain and maintain a current gap rather than the second target gap.

6. A method as recited in claim 1 wherein the power plant is an engine and the controlled brakes are wheel brakes.

7. A method as recited in claim 1 wherein the first and second gaps are longitudinal separations between the first and second vehicles.

8. A method as recited in claim 1 wherein:

the second vehicles is a truck that includes a retarder; and

the retarder is controlled at least in part based on a torque request generated by a torque request controller.

9. A method as recited in claim 8 wherein the brakes are wheel brakes and the retarder is also controlled in part by a brake controller that automatically controls the wheel brakes during driving.

10. A method as recited in claim 1 wherein:

the power plant output control scheme has a target output control line that defines a relative velocity versus gap relationship desired for use in controlling the first vehicle to attain the first target gap;

the braking control scheme has a target braking control line that defines a relative velocity versus gap relationship desired for use in controlling braking of the first vehicle to attain the second target gap; and

identifying a circumstance in which (i) the second vehicle is or will imminently be applying its brakes, and (ii) an actual current relative velocity of the first vehicle relative to the second vehicle is less than or equal to a targeted relative velocity defined by the target output control line at an actual current gap between the first and second vehicles; and

changing the braking control scheme to automatically control the brakes in a manner arranged to attain and maintain the first target gap rather than the second target gap.

11. A method of controlling a trailing vehicle to at least partially automatically maintain separation from a leading vehicle, the trailing vehicle having an engine and wheel brakes, the method comprising:

automatically controlling an output of the engine during driving in accordance with an engine control scheme arranged to attain and maintain a first target gap between the leading and trailing vehicles, the engine output control scheme having a target engine output control line that defines a relative velocity versus gap relationship desired for use in controlling the trailing vehicle to attain the first target gap; and

automatically controlling the wheel brakes during driving in accordance with a braking control scheme during first selected operating conditions arranged to attain and maintain a second target gap between the leading and trailing vehicles, the braking control scheme having a target braking control line that defines a relative velocity versus gap relationship desired for use in controlling braking of the first vehicle to attain the second target gap, wherein the second target gap is shorter than the first target gap and wherein the difference between the first and second control lines is a gap tolerance; and

wherein automatically controlling the wheel brakes in a manner arranged to attain and maintain the second target gap during the first selected operating conditions causes wheel brake braking requests to be generated during the first selected operating conditions only when the trailing vehicle has encroached upon the leading vehicle by at least the gap tolerance relative to a desired gap defined by the target engine output control line at a current actual relative velocity of the trailing vehicle relative to the leading vehicle.

12. A method as recited in claim 11 further comprising:

identifying a first circumstance in which (i) the leading vehicle is or will imminently be applying its brakes, and (ii) an actual current relative velocity of the trailing vehicle relative to the leading vehicle is less than or equal to a targeted relative velocity defined by the target engine output control line at an actual current gap between the leading and trailing vehicles; and

changing the braking control scheme for the trailing vehicle in response to the identification of the first circumstance to automatically control the brakes for the trailing vehicle in a manner arranged to attain and maintain the first target gap rather than the second target gap.

13. A method as recited in claim 11 further comprising:

identifying a first circumstance in which (i) the leading vehicle is or will imminently be applying its brakes, and (ii) an actual current relative velocity of the trailing vehicle relative to the leading vehicle is between a first targeted relative velocity defined by the target engine output control line at an actual current gap between the leading and trailing vehicles and a second targeted relative velocity defined by the target braking control line at the actual current gap; and

changing the braking control scheme for the trailing vehicle in response to the identification of the first circumstance to automatically control the brakes for the trailing vehicle in a manner arranged to attain and maintain the third target gap rather than the second target gap, the third target gap being intermediary between the first and second target gaps.

14. A method as recited in claim 11 wherein:

the leading and trailing vehicles are trucks, and the trailing vehicle includes a retarder; and

the retarder is controlled at least in part based on a torque request generated by a torque request controller.

15. A platoon controller for at least partially automatically controlling a host vehicle to attain and maintain a first target gap separation between the host vehicle and a second vehicle while the host vehicle is driving, the platoon controller comprising:

a torque request controller configured to determine torque requests suitable for attaining and maintaining the first target gap between the host and second vehicles while the host vehicle is driving under first selected operating conditions;

a brake request controller configured to determine brake requests suitable for attaining and maintaining a second target gap between the host and second vehicles while the host vehicle is driving under the first selected operating conditions, the second target gap being shorter than the first target gap.

16. A platoon controller as recited in claim 15 wherein the torque request controller and the brake request controller are components of a sliding mode controller.

17. A platoon controller as recited in claim 15 wherein the brake request controller is further configured to determine a brake request suitable for attaining and maintaining the first target gap during second selected operating conditions.

18. A platoon controller as recited in claim 15 wherein the brake request controller is further configured to determine a brake request suitable for attaining and maintaining the third target gap during second selected operating conditions, the third target gap being intermediary between the first and second target gaps.

19. A platoon controller as recited in claim 15 configured for use on a truck having an engine, a retarder and wheel brakes, wherein:

the torque requests generated by the torque request controller are configured to be used in conjunction with control of the engine and retarder but not the wheel brakes; and

the brake requests generated by the brake request controller are configured to be used in conjunction with control of the wheel brakes.

20. A truck having an engine, a retarder and wheel brakes and a platoon controller as recited in claim 19.