Real-time estimation of achievable angle, velocity, and acceleration capabilities of steering actuator

Patent metadata

Field	Value
Publication number	US-11827293-B2
Application number	US-202117171005-A
Country	US
Kind code	B2
Filing date	Feb 9, 2021
Priority date	Feb 9, 2021
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A system comprises a processor and a memory storing instructions which when executed by the processor configure the processor to estimate a rack force for a steering system of a vehicle based on current driving and environmental conditions and estimate a health of an actuator of the steering system of the vehicle. The instructions configure the processor to estimate maximum achievable angle, velocity, and acceleration for the actuator of the steering system based on the estimated rack force and the estimated health of the actuator. The instructions configure the processor to provide to the steering system a path planned for the vehicle based on the estimated maximum achievable angle, velocity, and acceleration for the actuator of the steering system.

First claim

What is claimed is:

1. A system comprising:
a processor; and
a memory storing instructions which when executed by the processor configure the processor to:
estimate a rack force for a steering system of a vehicle based on current driving and environmental conditions using a model;
estimate a health of an actuator of the steering system of the vehicle;
estimate maximum achievable angle, velocity, and acceleration for the actuator of the steering system based on the estimated rack force and the estimated health of the actuator;
provide to the steering system a path planned for the vehicle based on the estimated maximum achievable angle, velocity, and acceleration for the actuator of the steering system;
cause the steering system to execute the path in response to an angle, a velocity, and an acceleration for executing the path being within the estimated maximum achievable angle, velocity, and acceleration;
calculate, using a different method than that used by the model, a first rack force based on driving and environmental conditions used by the model to estimate the rack force;
calculate a second rack force based on actual measurements of parameters of the steering system of the vehicle;
verify accuracy of the estimated rack force based the first and second rack forces; and
update the model used to estimate the rack force based on the accuracy.

2. The system of claim 1 wherein the instructions configure the processor to provide the path to the steering system in response to an angle, a velocity, and an acceleration for executing the path being within the estimated maximum achievable angle, velocity, and acceleration.

3. The system of claim 1 wherein before providing the path to the steering system, the instructions configure the processor to modify the path to bring an angle, a velocity, and an acceleration for the actuator in conformity with the estimated maximum achievable angle, velocity, and acceleration.

4. The system of claim 1 wherein the instructions configure the processor to provide an indication based on the accuracy to check one or more sensors.

5. The system of claim 1 wherein the instructions configure the processor to:
obtain a first value for the rack force from a lookup table based on the nominal driving and environmental conditions;
obtain an adjustment factor from the model based on the current driving and environmental conditions; and
estimate the rack force by multiplying the first value for the rack force by the adjustment factor.

6. The system of claim 5 wherein the instructions configure the processor to:
calculate a first set of rack forces at a first set of vehicle speeds and a first set of steering data;
estimate a second set of rack forces for a second set of vehicle speeds and a second set of steering data by interpolating the first set of rack forces; and
generate the lookup table including the first and second sets of vehicle speeds.

7. The system of claim 5 wherein the instructions configure the processor to train the model to:
calculate rack forces at different driving and environmental conditions; and
generate the adjustment factor by comparing the first rack force calculated at the current driving and environmental conditions to a third rack force calculated at the nominal driving and environmental conditions.

8. A method comprising:
estimating a rack force for a steering system of a vehicle based on current driving and environmental conditions using a model;
estimating a health of an actuator of the steering system of the vehicle;
estimating maximum achievable angle, velocity, and acceleration for the actuator of the steering system based on the estimated rack force and the estimated health of the actuator;
providing to the steering system a path planned for the vehicle based on the estimated maximum achievable angle, velocity, and acceleration for the actuator of the steering system;
executing the path using the steering system in response to an angle, a velocity, and an acceleration for executing the path being within the estimated maximum achievable angle, velocity, and acceleration;
calculate, using a different method than that used by the model, a first rack force based on driving and environmental conditions used by the model to estimate the rack force;
calculate a second rack force based on actual measurements of parameters of the steering system of the vehicle;
verify accuracy of the estimated rack force based the first and second rack forces; and
update the model used to estimate the rack force based on the accuracy.

9. The method of claim 8 further comprising providing the path to the steering system in response to an angle, a velocity, and an acceleration for executing the path being within the estimated maximum achievable angle, velocity, and acceleration.

10. The method of claim 8 further comprising before providing the path to the steering system, modify the path to bring an angle, a velocity, and an acceleration for the actuator in conformity with the estimated maximum achievable angle, velocity, and acceleration.

11. The method of claim 8 further comprising providing an indication based on the accuracy to check one or more sensors.

12. The method of claim 8 further comprising:
obtaining a first value for the rack force from a lookup table based on nominal driving and environmental conditions;
obtaining an adjustment factor from the model based on the current driving and environmental conditions; and
estimating the rack force by multiplying the first value for the rack force by the adjustment factor.

13. The method of claim 12 further comprising:
calculating a first set of rack forces at a first set of vehicle speeds and a first set of steering data;
estimating a second set of rack forces for a second set of vehicle speeds and a second set of steering data by interpolating the first set of rack forces; and
generating the lookup table including the first and second sets of vehicle speeds.

14. The method of claim 12 further comprising training the model to:
calculate rack forces at different driving and environmental conditions; and
generate the adjustment factor by comparing the first rack force calculated at the current driving and environmental conditions to a third rack force calculated at the nominal driving and environmental conditions.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Lin Wen-Chiao
• Badiru Ibrahim A
• Allan Alexander M
• Yu Bo
• Zhang Qi
• Au Christopher C

Classifications

• B62D5/049 Primary

  detecting sensor failures · CPC title

• B62D3/126

  characterised by the rack · CPC title

• B62D5/0484

  for reaction to failures, e.g. limp home · CPC title

• B62D5/0487

  detecting motor faults (B62D5/0496 takes precedence) · CPC title

• B62D5/0457 Primary

  characterised by control features of the drive means as such · CPC title