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US-20260125109-A1 - METHOD AND ALGORITHM TO VIRTUALLY MEASURE AND ESTIMATE STEERING RACK FORCE AND VALIDATE SENSORY DATA

US20260125109A1US 20260125109 A1US20260125109 A1US 20260125109A1US-20260125109-A1

Abstract

A vehicle includes a system that performs a method of operating the vehicle. A steering rack is coupled to at least one of a left wheel and a right wheel. A sensor obtains a measurement of a dynamic parameter of the vehicle related to a force at the steering rack. A processor determines a first estimate of a rack force resulting from the force based on the measurement of the dynamic parameter, obtains a second estimate of the rack force based on a signal from a road wheel actuator coupled to the steering rack, selects an arbitrated rack force from the first estimate of the rack force and the second estimate of the rack force, and activates a hand wheel actuator coupled to a steering wheel of the vehicle based on the arbitrated rack force to generate a feedback torque at the steering wheel.

Inventors

  • Amin Habibnejad Korayem
  • Seyedeh Asal Nahidi
  • Mahdokht Ezati
  • SeyedAlireza Kasaiezadeh Mahabadi
  • Hojjat Izadi

Assignees

  • GM Global Technology Operations LLC

Dates

Publication Date
20260507
Application Date
20241101

Claims (20)

  1. 1 . A method of operating a vehicle, comprising: obtaining a measurement of a dynamic parameter of the vehicle related to a force at a steering rack of the vehicle, the steering rack coupled to at least one of a left wheel and a right wheel; determining a first estimate of a rack force resulting from the force based on the measurement of the dynamic parameter; obtaining a second estimate of the rack force based on a signal from a road wheel actuator coupled to the steering rack; selecting an arbitrated rack force from the first estimate of the rack force and the second estimate of the rack force; and activating a hand wheel actuator coupled to a steering wheel of the vehicle based on the arbitrated rack force to generate a feedback torque at the steering wheel.
  2. 2 . The method of claim 1 , wherein the dynamic parameter includes at least one of: (i) an externally applied force on a tire; (ii) an acceleration obtained at an inertial measurement unit (IMU); (iii) a road wheel angle; and (iv) a longitudinal velocity of the vehicle.
  3. 3 . The method of claim 1 , further comprising determining a right wheel estimate of the rack force using forces on a front right wheel of the vehicle, determining a left wheel estimate of the rack force using forces on a front left wheel of the vehicle, and determining the first estimate of the rack force based on the right wheel estimate and the left wheel estimate.
  4. 4 . The method of claim 1 , further comprising determining a fault in at least one of: (i) the measurement of the dynamic parameter used to calculate the first estimate; and (ii) the signal from the road wheel actuator used to calculate the second estimate.
  5. 5 . The method of claim 4 , further comprising selecting the second estimate as the arbitrated rack force when no fault is found in the signal from the road wheel actuator.
  6. 6 . The method of claim 1 , wherein at least one of the first estimate of the rack force and the second estimate of the rack force includes a temporal sequence of forces.
  7. 7 . The method of claim 1 , wherein the steering wheel and the steering rack are mechanically disconnected from each other and are each coupled to a steer-by-wire system.
  8. 8 . A system for operating a vehicle, comprising: a steering rack coupled to at least one of a left wheel and a right wheel; a sensor for obtain a measurement of a dynamic parameter of the vehicle related to a force at the steering rack; a processor configured to: determine a first estimate of a rack force resulting from the force based on the measurement of the dynamic parameter; obtain a second estimate of the rack force based on a signal from a road wheel actuator coupled to the steering rack; select an arbitrated rack force from the first estimate of the rack force and the second estimate of the rack force; and activate a hand wheel actuator coupled to a steering wheel of the vehicle based on the arbitrated rack force to generate a feedback torque at the steering wheel.
  9. 9 . The system of claim 8 , wherein the dynamic parameter includes at least one of: (i) an externally applied force on a tire; (ii) an acceleration obtained at an inertial measurement unit (IMU); (iii) a road wheel angle; and (iv) a longitudinal velocity of the vehicle.
  10. 10 . The system of claim 8 , wherein the processor is further configured to determine a right wheel estimate of the rack force using forces on a front right wheel of the vehicle, determine a left wheel estimate of the rack force using forces on a front left wheel of the vehicle, and determine the first estimate of the rack force based on the right wheel estimate and the left wheel estimate.
  11. 11 . The system of claim 8 , wherein the processor is further configured to determine a fault in at least one of: (i) the measurement of the dynamic parameter used to calculate the first estimate; and (ii) the signal from the road wheel actuator used to calculate the second estimate.
  12. 12 . The system of claim 11 , wherein the processor is further configured to select the second estimate as the arbitrated rack force when no fault is found in the signal from the road wheel actuator.
  13. 13 . The system of claim 8 , wherein at least one of the first estimate of the rack force and the second estimate of the rack force includes a temporal sequence of forces.
  14. 14 . The system of claim 8 , wherein the steering wheel and the steering rack are mechanically disconnected from each other and are each coupled to a steer-by-wire system.
  15. 15 . A vehicle, comprising: a steering wheel; a steering rack coupled to at least one of a left wheel and a right wheel; a sensor for obtain a measurement of a dynamic parameter of the vehicle related to a force at the steering rack; a steer-by-wire system coupled to the steering wheel and to the steering rack, the steer-by-wire system including a processor configured to: determine a first estimate of a rack force resulting from the force based on the measurement of the dynamic parameter; obtain a second estimate of the rack force based on a signal from a road wheel actuator coupled to the steering rack; select an arbitrated rack force from the first estimate of the rack force and the second estimate of the rack force; and activate a hand wheel actuator coupled to the steering wheel of the vehicle based on the arbitrated rack force to generate a feedback torque at the steering wheel.
  16. 16 . The vehicle of claim 15 , wherein the dynamic parameter includes at least one of: (i) an externally applied force on a tire; (ii) an acceleration obtained at an inertial measurement unit (IMU); (iii) a road wheel angle; and (iv) a longitudinal velocity of the vehicle.
  17. 17 . The vehicle of claim 15 , wherein the processor is further configured to determine a right wheel estimate of the rack force using forces on a front right wheel of the vehicle, determine a left wheel estimate of the rack force using forces on a front left wheel of the vehicle, and determine the first estimate of the rack force based on the right wheel estimate and the left wheel estimate.
  18. 18 . The vehicle of claim 15 , wherein the processor is further configured to determine a fault in at least one of: (i) the measurement of the dynamic parameter used to calculate the first estimate; and (ii) the signal from the road wheel actuator used to calculate the second estimate.
  19. 19 . The vehicle of claim 18 , wherein the processor is further configured to select the second estimate as the arbitrated rack force when no fault is found in the signal from the road wheel actuator.
  20. 20 . The vehicle of claim 15 , wherein at least one of the first estimate of the rack force and the second estimate of the rack force includes a temporal sequence of forces.

Description

The subject disclosure relates to the operation of a vehicle, and in particular, to a system and method for applying a feedback torque to a steering wheel of a steer-by-wire steering system of the vehicle to correspond to a force at a steering rack of the vehicle. Steer-by-wire systems have been developed to steer a vehicle. In a steer-by-wire system, there is no mechanical connection between a steering wheel and a road wheel actuator that steers the wheels of the vehicle. Instead, communication is between the steering wheel and a controller and between the controller and the road wheel actuator. Due to the lack of mechanical connection, external forces occurring at the steering rack, such as a sudden impulse when the vehicle encounters a pothole, are not translated to the steering wheel. Thus, the driver can be unaware of the driving conditions and external forces. Accordingly, it is desirable to provide a system and method for providing a feedback torque to the driver to better immerse the driver in the driving experience. SUMMARY In one exemplary embodiment, a method of operating a vehicle is disclosed. A measurement of a dynamic parameter of the vehicle related to a force at a steering rack of the vehicle is obtained. The steering rack is coupled to at least one of a left wheel and a right wheel. A first estimate of a rack force is determined, the first estimate resulting from the force based on the measurement of the dynamic parameter. A second estimate of the rack force is determined, the second estimated based on a signal from a road wheel actuator coupled to the steering rack. An arbitrated rack force is selected from the first estimate of the rack force and the second estimate of the rack force. A hand wheel actuator coupled to a steering wheel of the vehicle is activated based on the arbitrated rack force to generate a feedback torque at the steering wheel. In addition to one or more of the features described herein, the dynamic parameter includes at least one of an externally applied force on a tire, an acceleration obtained at an inertial measurement unit (IMU), a road wheel angle, and a longitudinal velocity of the vehicle. In addition to one or more of the features described herein, the method further includes determining a right wheel estimate of the rack force using forces on a front right wheel of the vehicle, determining a left wheel estimate of the rack force using forces on a front left wheel of the vehicle, and determining the first estimate of the rack force based on the right wheel estimate and the left wheel estimate. In addition to one or more of the features described herein, the method further comprising determining a fault in at least one of the measurement of the dynamic parameter used to calculate the first estimate and the signal from the road wheel actuator used to calculate the second estimate. In addition to one or more of the features described herein, the method further includes selecting the second estimate as the arbitrated rack force when no fault is found in the signal from the road wheel actuator. In addition to one or more of the features described herein, at least one of the first estimate of the rack force and the second estimate of the rack force includes a temporal sequence of forces. In addition to one or more of the features described herein, the steering wheel and the steering rack are mechanically disconnected from each other and are each coupled to a steer-by-wire system. In another exemplary embodiment, a system for operating a vehicle is disclosed. The system includes a steering rack coupled to at least one of a left wheel and a right wheel, a sensor for obtain a measurement of a dynamic parameter of the vehicle related to a force at the steering rack, and a processor. The processor is configured to determine a first estimate of a rack force resulting from the force based on the measurement of the dynamic parameter, obtain a second estimate of the rack force based on a signal from a road wheel actuator coupled to the steering rack, select an arbitrated rack force from the first estimate of the rack force and the second estimate of the rack force, and activate a hand wheel actuator coupled to a steering wheel of the vehicle based on the arbitrated rack force to generate a feedback torque at the steering wheel. In addition to one or more of the features described herein, the dynamic parameter includes at least one of an externally applied force on a tire, an acceleration obtained at an inertial measurement unit (IMU), a road wheel angle, and (iv) a longitudinal velocity of the vehicle. In addition to one or more of the features described herein, the processor is further configured to determine a right wheel estimate of the rack force using forces on a front right wheel of the vehicle, determine a left wheel estimate of the rack force using forces on a front left wheel of the vehicle, and determine the first estimate of the rack force based on the right whee