Systems and methods for adjusting a steering wheel of a vehicle during operating mode transitions

A system for a vehicle, comprising:

• a controller in operable communication with an automated driving system (ADS) configured for autonomous steering of the vehicle, a road wheel control system configured for controlling a road wheel angle of wheels of the vehicle in response to instructions received from the ADS or manual rotation of a steering wheel of the vehicle, and a steering wheel control system configured for adjusting a steering wheel angle and torque feedback of the steering wheel in response to autonomous steering of the vehicle by the ADS, wherein the controller is configured to, by one or more processors thereof:
• receive a hands-on request instructing a driver to grip the steering wheel prior to transitioning from a hands-off mode wherein steering of the vehicle is controlled by the ADS and the driver is not required to grip the steering wheel to a hands-on mode that requires the driver to grip the steering wheel;
• determine, in response to receiving the hands-on request, an expected steering ratio and an expected transition duration, wherein the expected steering ratio is a specific steering ratio corresponding to a current road wheel angle as designated by the hands-on mode, wherein the expected transition duration is a period of time for transition between a current steering ratio and the expected steering ratio;
• determine a steering ratio trajectory based on the current steering ratio, the expected steering ratio, and the expected transition duration, wherein the steering ratio trajectory includes a series of reference steering ratios at corresponding times during the expected transition duration;
• and
• transition from the current steering ratio to the expected steering ratio using the steering ratio trajectory.

A vehicle, comprising:

• a steering wheel configured for manual steering of the vehicle;
• an automated driving system (ADS) configured for autonomous steering of the vehicle;
• a road wheel control system configured for controlling a road wheel angle of wheels of the vehicle in response to instructions received from the ADS or manual rotation of the steering wheel;
• a steering wheel control system configured for adjusting a steering wheel angle and a torque feedback of the steering wheel in response to autonomous steering of the vehicle by the ADS;
• a controller configured to, by one or more processors thereof:
• receive a hands-on request instructing a driver to grip the steering wheel prior to transitioning from a hands-off mode wherein steering of the vehicle is controlled by the ADS and the driver is not required to grip the steering wheel to a hands-on mode that requires the driver to grip the steering wheel;
• determine, in response to receiving the hands-on request, an expected steering ratio and an expected transition duration, wherein the expected steering ratio is a specific steering ratio corresponding to a current road wheel angle as designated by the hands-on mode, wherein the expected transition duration is a period of time for transition between a current steering ratio and the expected steering ratio;
• determine a steering ratio trajectory based on the current steering ratio, the expected steering ratio, and the expected transition duration, wherein the steering ratio trajectory includes a series of reference steering ratios at corresponding times during the expected transition duration;
• and
• transition from the current steering ratio to the expected steering ratio using the steering ratio trajectory.