Determining control characteristics for an autonomous driving vehicle

Patent metadata

Field	Value
Publication number	US-10272924-B2
Application number	US-201615383843-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Dec 19, 2016
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

Described is a system and method that provides the ability for an autonomous driving vehicle (ADV) to determine (or estimate) one or more control characteristics for the ADV. In order to determine these control characteristics, the system may perform one or more driving maneuvers such as an acceleration or deceleration maneuver, and a constant velocity maneuver. By performing these maneuvers using various known forces, the system may then perform various calculations to obtain one or more unknown characteristics. For example, the system may determine as estimated mass of the ADV, and as a result, adjust (or tune) various controls of the ADV based on the estimated mass.

First claim

What is claimed is:

1. A computer-implemented method of determining characteristics of an autonomous driving vehicle (ADV), comprising:
initiating a first driving maneuver for the ADV, the first driving maneuver including accelerating the ADV to a predetermined velocity;
determining a first tractive force required by the ADV to achieve the acceleration during the first driving maneuver;
in response to reaching the predetermined velocity, initiating a second driving maneuver including maintaining a constant velocity for the ADV;
determining a second tractive force required by the ADV to maintain the constant velocity during the second driving maneuver;
calculating an estimated mass of the ADV based on the determined first tractive force, the determined second tractive force, and a rate of the acceleration during the first driving maneuver, wherein initiating the first and second driving maneuvers are performed during a first set of load characteristics for the ADV;
detecting a change from the first set of load characteristics to second set of load characteristics for the ADV; and
in response to detecting the change from the first set of load characteristics to the second set of load characteristics for the ADV, determining an updated estimated mass of the ADV for the second set of load characteristics different from the first set of load characteristics.

2. The method of claim 1 , wherein the estimated mass is determined for the first set of load characteristics of the ADV.

3. The method of claim 2 , wherein each of the first and second tractive forces correspond to a drive torque produced by an engine of the ADV.

4. The method of claim 3 , wherein initiating the first and second driving maneuvers are performed as part of an initialization process for a throttle control rate that controls an output of the drive torque produced by the engine.

5. The method of claim 4 , wherein the initialization process for the throttle control rate includes determining a throttle control ratio based on the estimated mass for the first set of load characteristics.

6. The method of claim 5 , further comprising:
adjusting the throttle control rate based on the determined throttle control ratio with the updated estimated mass during the second set of load characteristics.

7. The method of claim 6 , wherein the first or the second set of load characteristics include a number of passengers or a passenger load within the ADV.

8. The method of claim 1 , wherein accelerating the ADV to the predetermined velocity comprises a substantially constant acceleration.

9. The method of claim 1 , wherein the predetermined velocity or the acceleration is selected such that a drag force component of a resistance force is minimal or substantially constant during the first and second driving maneuvers.

10. The method of claim 1 , wherein the second tractive force is determined as being substantially equal to a resistance force during the second driving maneuver as a result of the ADV travelling at the predetermined velocity during the second driving maneuver.

11. The method of claim 1 , wherein at least one of the first driving maneuver and the second driving maneuver are performed autonomously by the ADV.

12. A non-transitory machine-readable medium having instructions stored therein, which when executed by a processor coupled to an autonomous driving vehicle (ADV), cause the processor to perform operations, the operations comprising:
initiating a first driving maneuver for the ADV, the first driving maneuver including accelerating or decelerating the ADV to a predetermined velocity;
determining a first tractive force required by the ADV to achieve the acceleration or deceleration during the first driving maneuver;
initiating a second driving maneuver including maintaining a constant velocity for the ADV;
determining a second tractive force required by the ADV to maintain the constant velocity during the second driving maneuver;
calculating an estimated mass of the ADV based on the determined first tractive force, the determined second tractive force, and a rate of the acceleration or deceleration during the first driving maneuver, wherein the estimated mass is determined for a first set of load characteristics of the ADV;
detecting a change from the first set of load characteristics to a second set of load characteristics for the ADV; and
in response to detecting the change from the first set of load characteristics to the second set of load characteristics for the ADV, determining an updated estimated mass of the ADV for the second set of load characteristics different from the first set of load characteristics.

13. The medium of claim 12 , the operations further comprising adjusting a throttle control rate based on the estimated mass, wherein the throttle control rate controls an output of a drive torque produced by an engine of the ADV.

14. The medium of claim 13 , wherein initiating the first and second driving maneuvers are performed as part of an initialization process for the throttle control rate.

15. The medium of claim 14 , wherein the initialization process for the throttle control rate includes determining a throttle control ratio with the estimated mass during the first set of load characteristics.

16. The medium of claim 15 , the operations further comprising:
adjusting the throttle control rate based on the determined throttle control ratio with the updated estimated mass during the second set of load characteristics.

17. A control system for an autonomous driving vehicle (ADV), comprising:
a processor; and
a memory coupled to the processor to store instructions, which when executed by the processor, cause the processor to perform operations, the operations including:
initiating a first driving maneuver for the ADV, the first driving maneuver including accelerating the ADV to a predetermined velocity,
determining a first tractive force required by the ADV to achieve the acceleration during the first driving maneuver,
initiating a second driving maneuver including maintaining a constant velocity for the ADV,
determining a second tractive force required by the ADV to maintain the constant velocity during the second driving maneuver,
calculating an estimated mass of the ADV based on the determined first tractive force, the determined second tractive force, and a rate of the acceleration during the first driving maneuver, wherein initiating the first and second driving maneuvers are performed during a first set of load characteristics for the ADV;
detecting a change from the first set of load characteristics to a second set of load characteristics for the ADV; and
in response to detecting the change from e first set of load characteristics to the second set of load characteristics for the ADV, determining an updated estimated mass of the ADV for the second set of load characteristics different from the first set of load characteristics.

18. The system of claim 17 , the operations further comprising adjusting a throttle control rate based on the estimated mass, wherein the throttle control rate controls an output of a drive torque produced by an engine of the ADV.

19. The system of claim 18 , wherein initiating the first and second driving maneuvers are performed as part of an initialization process for the throttle control rate.

20. The system of claim 19 , the operations further comprising:
readjusting the throttle control rate based on the updated estimated mass during the second set of load characteristics.

Assignees

• Baidu Usa Llc

Inventors

• Luo Qi
• Kong Qi
• Zhu Fan
• Hu Sen
• Yu Xiang
• Yang Guang
• Wang Jingao

Classifications

• B60W30/143

  Speed control (B60W30/16 takes precedence) · CPC title

• B60W40/13 Primary

  Load or weight · CPC title

• B60W2710/0666

  Engine torque · CPC title

• B60W2710/0672

  Torque change rate · CPC title

• B60W30/18 Primary

  Propelling the vehicle · CPC title