Granted Patent B2

US 12,735,094 · App. 18/928,896 · Granted Sep 15, 2026

Inventors: Mahdokht Ezati (Pickering, CA); Amin Habibnejad Korayem (Markham, CA); SeyedAlireza Kasaiezadeh Mahabadi (Novi, MI); Seyedeh Asal Nahidi (North York, CA); Douglas James Spry (Clarkston, MI); Hojjat Izadi (Richmond Hill, CA)

Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC

B62D5/0487B62D5/0484B62D5/006

Abstract

Claims (79)

1 . A method comprising:

obtaining, via one or more steering sensors of a vehicle, steering sensor data pertaining to a steering system of the vehicle, the steering system comprising a motor and a rack;

determining, via a processor of the vehicle, an estimated electric current of the motor based on the steering sensor data;

comparing, via the processor, the estimated electric current with a predetermined electric current threshold; and

determining, via the processor, a condition of the steering system of the vehicle, including whether movement of the vehicle is inhibited and whether the rack has a failure, based on whether the estimated electric current is greater than or equal to the predetermined electric current threshold;

wherein the determining of the estimated electric current of the motor is performed by the processor using an observer to estimate an angle of a road wheel actuator (RWA) motor and current by integrating a prediction model for the RWA motor and a measurement model for observations, along with use of a Kalman filter; and

wherein the determining of the estimated electric current of the motor is performed by the processor also by modeling the motor as a direct current (DC) permanent magnet motor, and by modeling electrical properties of the motor as a series connection of a resistor, an inductor, and a voltage source that represents back-EMF produced by the motor, and further including a relationship between a hand wheel actuator (HWA) requested rack displacement and a resulting RWA road wheel angle.

2 . The method of claim 1 , wherein:

the steering system comprises a steer-by-wire steering system having a feedback motor coupled to a steering wheel of the vehicle and a road wheel actuator (RWA) motor coupled to a road wheel of the vehicle; and

the estimated electric current pertains to the RWA motor that is coupled to the road wheel of the vehicle.

3 . The method of claim 1 , further comprising:

taking a vehicle control action, in accordance with instructions provided by the processor, based on the condition that is determined via the processor.

4 . The method of claim 1 , further comprising:

providing a notification for a driver of the vehicle based on the condition, including instructions for an action for the driver to take to remedy the condition, via a display screen of the vehicle in accordance with the instructions provided thereto via the processor.

5 . The method of claim 1 , further comprising:

obtaining, via one or more cameras of the vehicle, camera data as to one or more external objects that are in proximity to the vehicle;

determining that the condition comprises an operational condition in which the steering system is operating correctly, when the estimated electric current is less than the predetermined electric current threshold;

determining that the condition comprises a rack failure condition in which a mechanical failure is present for the rack, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera data does not show any external objects that are deemed to be inhibiting movement of the vehicle; and

determining that the condition comprises a rack stuck condition in which the rack is deemed to be stuck by the one or more external objects, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera shows an external object that is deemed to be inhibiting movement of the vehicle.

6 . The method of claim 5 , further comprising:

providing a service instruction for a driver of the vehicle, via instructions provide by the processor, to obtain repair of the steering system when the condition comprises the rack failure condition; and

providing a steering action instruction for the driver of the vehicle, via the instructions provide by the processor, when the condition comprises the rack stuck condition.

7 . The method of claim 1 , wherein the determining of the estimated electric current of the motor is performed by the processor also by utilizing pinion angle sensor measurements and rack force estimations received from an actuator and determining the current based on the rack force using a mathematical model that represents an interaction between the rack and pinion, along with an electrical model that represents the interaction between motor torque and the current.

8 . The method of claim 1 , wherein the Kalman filter is utilized by the processor in estimating an angle of the motor along with the current of the motor utilizing a requested disk replacement (d r ag ), a motor voltage (V m ), a pinion angle (P), and rack force (F r ), and utilizing multiple predictions of the current at different points in time and using a motion model as well as measurements of the current using an observation model, along with a time delay for the Kalman filter.

9 . A system comprising:

one or more steering sensors of a vehicle configured to obtain steering sensor data pertaining to a steering system of the vehicle, the steering system comprising a motor and a rack; and

a processor that is coupled to the one or more steering sensors and that is configured to at least facilitate:

determining an estimated electric current of the motor based on the steering sensor data;

comparing the estimated electric current with a predetermined electric current threshold; and

determining a condition of the steering system of the vehicle, including whether movement of the vehicle is inhibited and whether the rack has a failure, based on whether the estimated electric current is greater than or equal to the predetermined electric current threshold;

wherein the processor is further configured to determine the estimated electric current of the motor by:

using an observer to estimate a motor angle for a road wheel actuator (RWA) motor and current by integrating a prediction model for the RWA motor and a measurement model for observations, along with use of a Kalman filter;

modeling the motor as a direct current (DC) permanent magnet motor, and by modeling electrical properties of the motor as a series connection of a resistor, an inductor, and a voltage source that represents back-EMF produced by the motor, and further including a relationship between a hand wheel actuator (HWA) requested rack displacement and a resulting RWA road wheel angle; and

utilizing pinion angle sensor measurements and rack force estimations received from an actuator and determining the current based on the rack force using a mathematical model that represents an interaction between the rack and pinion, along with an electrical model that represents the interaction between motor torque and current.

10 . The system of claim 9 , wherein:

the steering system comprises a steer-by-wire steering system having a feedback motor coupled to a steering wheel of the vehicle and a road wheel actuator (RWA) motor coupled to a road wheel of the vehicle; and

the estimated electric current pertains to the RWA motor that is coupled to the road wheel of the vehicle.

11 . The system of claim 9 , further comprising:

one or more cameras of the vehicle configured to obtain camera data as to one or more external objects that are in proximity to the vehicle;

wherein the processor is coupled to the one or more cameras and is further configured to at least facilitate:

determining that the condition comprises an operational condition in which the steering system is operating correctly, when the estimated electric current is less than the predetermined electric current threshold;

determining that the condition comprises a rack failure condition in which a mechanical failure is present for the rack, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera data does not show any external objects that are deemed to be inhibiting movement of the vehicle; and

determining that the condition comprises a rack stuck condition in which the rack is deemed to be stuck by the one or more external objects, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera shows an external object that is deemed to be inhibiting movement of the vehicle.

12 . The system of claim 11 , wherein the processor is further configured to at least facilitate:

providing a service instruction for a driver of the vehicle, via instructions provide by the processor, to obtain repair of the steering system when the condition comprises the rack failure condition; and

providing a steering action instruction for the driver of the vehicle, via the instructions provide by the processor, when the condition comprises the rack stuck condition.

13 . The system of claim 11 , wherein the processor is further configured to utilize the Kalman filter in estimating an angle of the motor along with the current of the motor utilizing a requested disk replacement (d r ag ), a motor voltage (V m ), a pinion angle (P), and rack force (F r ), and utilizing multiple predictions of the current at different points in time and using a motion model as well as measurements of the current using an observation model, along with a time delay for the Kalman filter.

14 . A vehicle comprising:

a steering system comprising a steer-by-wire steering system having a rack as well as a feedback motor coupled to a steering wheel of the vehicle and a road wheel actuator (RWA) motor coupled to a road wheel of the vehicle; and

one or more steering sensors of the vehicle configured to obtain steering sensor data pertaining to the steering system of the vehicle;

one or more cameras of the vehicle configured to obtain camera data as to one or more external objects that are in proximity to the vehicle; and

a processor that is coupled to the one or more steering sensors and to the one or more cameras and that is configured to at least facilitate:

determining an estimated electric current of the RWA motor based on the steering sensor data;

comparing the estimated electric current with a predetermined electric current threshold; and

determining a condition of the steering system of the vehicle, including whether movement of the vehicle is inhibited and whether the rack has a failure, based on whether the estimated electric current is greater than or equal to the predetermined electric current threshold;

wherein the processor is coupled to the one or more cameras and is further configured to at least facilitate:

determining that the condition comprises an operational condition in which the steering system is operating correctly, when the estimated electric current is less than the predetermined electric current threshold;

determining that the condition comprises a rack failure condition in which a mechanical failure is present for the rack, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera data does not show any external objects that are deemed to be inhibiting movement of the vehicle; and

determining that the condition comprises a rack stuck condition in which the rack is deemed to be stuck by the one or more external objects, when both of the following conditions are satisfied:

the estimated electric current is greater than or equal to the predetermined electric current threshold; and

the camera shows an external object that is deemed to be inhibiting movement of the vehicle;

wherein the processor is further configured to at least facilitate:

providing a service instruction for a driver of the vehicle, via instructions provide by the processor, to obtain repair of the steering system when the condition comprises the rack failure condition; and

providing a steering action instruction for the driver of the vehicle, via the instructions provide by the processor, when the condition comprises the rack stuck condition; and

wherein the processor is further configured to determine the estimated electric current of the motor by:

using an observer to estimate a motor angle for the RWA motor and current by integrating a prediction model for the RWA motor and a measurement model for observations, along with use of a Kalman filter;

modeling the motor as a direct current (DC) permanent magnet motor, and by modeling electrical properties of the motor as a series connection of a resistor, an inductor, and a voltage source that represents back-EMF produced by the motor, and further including a relationship between a hand wheel actuator (HWA) requested rack displacement and a resulting RWA road wheel angle;

utilizing pinion angle sensor measurements and rack force estimations received from an actuator and determining the current based on the rack force using a mathematical model that represents an interaction between the rack and pinion, along with an electrical model that represents the interaction between motor torque and current; and

utilizing the Kalman filter in estimating an angle of the motor along with the current of the motor utilizing a requested disk replacement (d r ag ), a motor voltage (V m ), a pinion angle (P), and rack force (F r ), and utilizing multiple predictions of the current at different points in time and using a motion model as well as measurements of the current using an observation model, along with a time delay for the Kalman filter.

Assignments (1)

Continuity (1)

References Cited (16)