Systems and methods for adaptive braking using brake wear data

• US 10,328,802 B2
• Filed: 11/11/2016
• Issued: 06/25/2019
• Est. Priority Date: 11/11/2016
• Status: Active Grant

• Current Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Gaither, Geoffrey David, Payne, Joshua D.
• Primary Examiner(s): Wiltey, Nicholas K
• Application Number:
  US15/349,676
• Publication Number:
  US 20180134161A1
• Time in Patent Office: 956 Days
• Field of Search: None
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 3/0076 relating to braking
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 2210/36 Global Positioning System [GPS]
• CPC Class Codes: B60T 2270/406 Test-mode; Self-diagnosis
• CPC Class Codes: B60T 2270/604 Merging friction therewith; Adjusting their repartition
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: Y10S 903/947 Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

System, methods, and other embodiments described herein relate to adapting a manner of braking according to brake wear of friction brakes of a vehicle. In one embodiment, a method includes identifying whether brake wear of at least one of the friction brakes satisfies a threshold for modifying a deceleration pattern of the vehicle. The deceleration pattern indicates how regenerative brakes and the friction brakes are engaged to decelerate the vehicle individually for each wheel of the vehicle. The method includes adjusting the deceleration pattern according to at least the brake wear of the at least one of the friction brakes to transition braking from the at least one of the friction brakes to the regenerative brakes. The method includes controlling the vehicle to decelerate according to the deceleration pattern upon receiving a control input.

Claims

1. An adaptive control system of a vehicle that includes both regenerative brakes and friction brakes, comprising:

one or more processors;

a memory communicably coupled to the one or more processors and storing;

a brake wear module including instructions that when executed by the one or more processors cause the one or more processors to identify whether brake wear of at least one of the friction brakes satisfies a threshold for modifying a deceleration pattern of the vehicle, wherein the deceleration pattern indicates how the regenerative brakes and the friction brakes are engaged to decelerate the vehicle individually for each wheel of the vehicle, and

wherein the deceleration pattern indicates at least an amount of simultaneous blending between using the friction brakes and using the regenerative brakes to decelerate the vehicle; and

a deceleration module including instructions that when executed by the one or more processors cause the one or more processors to adjust, prior to receiving a control input to activate braking in the vehicle, the deceleration pattern according to at least the brake wear of the at least one of the friction brakes to transition braking from the at least one of the friction brakes to the regenerative brakes, and

wherein the deceleration module includes instructions to control the vehicle to decelerate according to the deceleration pattern upon receiving a control input.

2. The adaptive control system of claim 1, wherein the brake wear module further includes instructions to determine the brake wear associated with the friction brakes of the vehicle including instructions to compute a degree of wear for at least brakes pads of the friction brakes after each braking event in the vehicle,

wherein the deceleration module includes instructions to adjust the deceleration pattern to cause at least one of the regenerative brakes to be activated at least partially in place of the at least one of the friction brakes to compensate for the brake wear, and

wherein the control input is a signal generated from depressing a brake pedal or from releasing an accelerator pedal of the vehicle.

3. The adaptive control system of claim 2, wherein the brake wear module includes instructions to determine the brake wear for the at least one friction brake including instructions to:

in response to detecting a braking event where the friction brakes are engaged to decelerate the vehicle, collect braking data that includes at least a brake stroke applied to the brake pedal of the vehicle,

analyze the braking event as a function of at least the braking data to generate an intermediate brake wear that identifies wear caused by the braking event for each of the friction brakes, and

generate the degree of wear by accumulating the intermediate brake wear with a previous degree of wear that is from prior to the braking event for each of the friction brakes.

4. The adaptive control system of claim 3, wherein the brake wear module includes instructions to collect the braking data including instructions to receive a control signal from a brake wear sensor that indicates a thickness of a brake pad for each of the friction brakes, receive a signal identifying an ambient air temperature, receiving a signal identifying the brake stroke and a duration of the brake stroke, and retrieving an age of the friction brakes from a register, and

wherein the brake wear module includes instructions to analyze the braking event including instructions to input the braking data to a lookup table to retrieve an estimated value for the intermediate brake wear for the braking event.

5. The adaptive control system of claim 3, wherein the brake wear module includes instructions to provide an indication according to the intermediate brake wear that identifies to a driver an effect of the braking event on brake life of the friction brakes.

6. The adaptive control system of claim 1, wherein the deceleration pattern further indicates a lower threshold speed of the vehicle at which the regenerative brakes are disengaged and the friction brakes are used to decelerate the vehicle, and an extent to which the regenerative brakes are engaged when coasting, and

wherein the deceleration module includes instructions to adjust the deceleration pattern including instructions to adjust a coaching system of the vehicle according to the deceleration pattern to provide indications to a driver to permit the vehicle to coast and use the regenerative brakes in place of applying the friction brakes.

7. The adaptive control system of claim 1, wherein the deceleration module includes instructions to adjust the deceleration pattern including instructions to engage the regenerative brakes according to an amount that correlates with the brake wear and a decrease in an effectiveness of the friction brakes caused by the brake wear to slow the vehicle using the regenerative brakes instead of the friction brakes,

wherein the deceleration module includes instructions to adjust the deceleration pattern including instructions to modify one or more of (i) an amount by which the regenerative brakes are engaged during coasting of the vehicle, (ii) an amount by which the regenerative brakes are applied during the blending, and (iii) an amount by which the friction brakes are applied separately from the regenerative brakes, and

wherein the deceleration module includes the instructions to control the vehicle to brake according to the deceleration pattern including instructions to engage the regenerative brakes for a duration and a degree specified by the deceleration pattern.

8. The adaptive control system of claim 1, wherein the brake wear of the at least one of the friction brakes satisfies the threshold when the brake wear affects an ability of the at least one of the friction brakes to decelerate the vehicle,

wherein the brake wear module includes the instructions to determine the brake wear including instructions to individually identify the brake wear separately for each of the friction brakes, and

wherein the deceleration module includes instructions to adjust the deceleration pattern individually for each of the friction brakes and the regenerative brakes.

9. The adaptive control system of claim 1, wherein the vehicle is a hybrid electric vehicle, and wherein the friction brakes are disc brakes each comprising a brake pad in contact with a brake rotor when actuated to decelerate the vehicle.

10. A non-transitory computer-readable medium storing instructions that when executed by one or more processors cause the one or more processors to:

identify, for a vehicle that includes both friction brakes and regenerative brakes, whether brake wear of at least one of the friction brakes satisfies a threshold for modifying a deceleration pattern of the vehicle, wherein the deceleration pattern indicates how the regenerative brakes and the friction brakes are engaged to decelerate the vehicle individually for each wheel of the vehicle, and wherein the deceleration pattern indicates at least an amount of simultaneous blending between using the friction brakes and using the regenerative brakes to decelerate the vehicle;

adjust, prior to receiving a control input to activate braking in the vehicle, the deceleration pattern according to at least the brake wear of the at least one of the friction brakes to transition braking from the at least one of the friction brakes to the regenerative brakes; and

control the vehicle to decelerate according to the deceleration pattern upon receiving a control input.

11. The non-transitory computer-readable medium of claim 10, further comprising instructions to determine the brake wear associated with the friction brakes of the vehicle including instructions to compute a degree of wear for at least brakes pads of the friction brakes after each braking event in the vehicle including instructions to:

in response to detecting a braking event where the friction brakes are engaged to decelerate the vehicle, collect braking data that includes at least a brake stroke applied to a brake pedal of the vehicle,

analyze the braking event as a function of at least the braking data to generate an intermediate brake wear that identifies wear caused by the braking event for each of the friction brakes, and

generate the degree of brake wear by accumulating the intermediate brake wear with a previous degree of brake wear that is from prior to the braking event for each of the friction brakes.

12. The non-transitory computer-readable medium of claim 10, wherein the instructions to adjust the deceleration pattern include instructions to cause at least one of the regenerative brakes to be activated at least partially in place of the at least one of the friction brakes to compensate for the brake wear, wherein the control input is a signal generated from depressing a brake pedal or from releasing an accelerator pedal of the vehicle,

wherein the deceleration pattern indicates an amount of blending between using the friction brakes and using the regenerative brakes to decelerate the vehicle, a lower threshold speed of the vehicle at which the regenerative brakes are disengaged, and the friction brakes are used to decelerate the vehicle, and an extent to which the regenerative brakes are engaged when coasting, and

wherein the instructions to adjust the deceleration pattern include instructions to adjust a coaching system of the vehicle according to the deceleration pattern to provide indications to a driver to permit the vehicle to coast and use the regenerative brakes in place of applying the friction brakes.

13. The non-transitory computer-readable medium of claim 10, wherein the instructions to adjust the deceleration pattern include instructions to engage the regenerative brakes according to an amount that correlates with the brake wear and a decrease in an effectiveness of the friction brakes caused by the brake wear to slow the vehicle using the regenerative brakes instead of the friction brakes, wherein the instructions to control the vehicle to brake according to the deceleration pattern include instructions to engage the regenerative brakes for a duration and a degree specified by the deceleration pattern,

wherein the instructions to adjust the deceleration pattern include instructions to modify one or more of (i) an amount by which the regenerative brakes are engaged during coasting of the vehicle, (ii) an amount by which the regenerative brakes are applied during the blending, and (iii) an amount by which the friction brakes are applied separately from the regenerative brakes, and

wherein the brake wear of the at least one of the friction brakes satisfies the threshold when the brake wear affects an ability of the at least one of the friction brakes to decelerate the vehicle.

14. A method of adapting braking in a vehicle that includes both regenerative brakes and friction brakes, comprising:

identifying whether brake wear of at least one of the friction brakes satisfies a threshold for modifying a deceleration pattern of the vehicle, wherein the deceleration pattern indicates how the regenerative brakes and the friction brakes are engaged to decelerate the vehicle individually for each wheel of the vehicle, and wherein the deceleration pattern indicates at least an amount of simultaneous blending between using the friction brakes and using the regenerative brakes to decelerate the vehicle;

adjusting, prior to receiving a control input to activate braking in the vehicle, the deceleration pattern according to at least the brake wear of the at least one of the friction brakes to transition braking from the at least one of the friction brakes to the regenerative brakes; and

controlling the vehicle to decelerate according to the deceleration pattern upon receiving a control input.

15. The method of claim 14, further comprising:

determining the brake wear associated with the friction brakes of the vehicle by computing a degree of wear for at least brakes pads of the friction brakes after each braking event in the vehicle,

wherein adjusting the deceleration pattern causes at least one of the regenerative brakes to be activated at least partially in place of the at least one of the friction brakes to compensate for the brake wear, wherein the control input is a signal generated from depressing a brake pedal or from releasing an accelerator pedal of the vehicle.

16. The method of claim 15, wherein determining the brake wear for the friction brakes includes:

in response to detecting a braking event where the friction brakes are engaged to decelerate the vehicle, collecting braking data that includes at least a brake stroke applied to the brake pedal of the vehicle,

analyzing the braking event as a function of at least the braking data to generate an intermediate brake wear that identifies wear caused by the braking event for each of the friction brakes, and

generating the degree of wear by accumulating the intermediate brake wear with a previous degree of wear that is from prior to the braking event for each of the friction brakes.

17. The method of claim 16, further comprising:

providing an indication according to the intermediate brake wear that identifies to a driver an effect of the braking event on brake life of the friction brakes,

wherein collecting the braking data includes receiving a control signal from a brake wear sensor that indicates a thickness of a brake pad for each of the friction brakes, receiving a signal identifying an ambient air temperature, and retrieving an age of the friction brakes from a register, and

wherein analyzing includes using the braking data as an input to a lookup to retrieve an estimate of the brake wear for the braking event.

18. The method of claim 14, wherein the deceleration pattern further indicates a lower threshold speed of the vehicle at which the regenerative brakes are disengaged and the friction brakes are used to decelerate the vehicle, and an extent to which the regenerative brakes are engaged when coasting, and

wherein adjusting the deceleration pattern includes adjusting a coaching system of the vehicle according to the deceleration pattern to provide indications to a driver to permit the vehicle to coast and use the regenerative brakes in place of applying the friction brakes.

19. The method of claim 14, wherein adjusting the deceleration pattern includes engaging the regenerative brakes according to an amount that correlates with the brake wear and a decrease in an effectiveness of the friction brakes caused by the brake wear to slow the vehicle using the regenerative brakes instead of the friction brakes,

wherein adjusting the deceleration pattern includes modifying one or more of (i) an amount by which the regenerative brakes are engaged during coasting of the vehicle, (ii) an amount by which the regenerative brakes are applied during the blending, and (iii) an amount by which the friction brakes are applied separately from the regenerative brakes, and

wherein controlling the vehicle to brake according to the deceleration pattern includes engaging the regenerative brake for a duration and a degree specified by the deceleration pattern.

20. The method of claim 14, wherein the brake wear of the at least one of the friction brakes satisfies the threshold when the brake wear affects an ability of the at least one of the friction brakes to decelerate the vehicle,

wherein determining the brake wear includes individually identifying the brake wear separately for each of the friction brakes, and

wherein adjusting the deceleration pattern includes individually adjusting the deceleration pattern for each of the friction brakes and the regenerative brakes.