Haptic controller for road vehicles

A power assisted steering system for a motor driven road vehicle, the system including assist torque signal generating means arranged to generate an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed and effective to reduce the driver's steering effort, and a means for generating a haptic torque based upon vehicle yaw rate error which is arranged to be added to the torque assist signal such that when the yaw rate error builds up, corresponding to increasing steering instability of the vehicle, the haptic torque added to the torque assist signal reduces the effective road reaction feedback sensed by the driver in advance of any actual vehicle stability loss whereby to allow the driver to correct appropriately in good time before terminal steering instability is reached.

A power assisted steering system for a motor driven road vehicle, the system including assist torque signal generating means arranged to generate an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed and effective to reduce the driver's steering effort, and a means for generating a haptic torque based upon vehicle lateral acceleration error which is arranged to be added to the torque assist signal such that when the lateral acceleration error builds up, corresponding to increasing steering instability of the vehicle, the haptic torque added to the torque assist signal reduces the effective road reaction feedback sensed by the driver in advance of any actual vehicle stability loss whereby to allow the driver to coirect appropriately in good time before terminal steering instability is reached.

A power assisted steering system for a motor driven vehicle, the system including assist torque signal generating means arranged to generate an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed and effective to decrease the driver's steering effort, and a means for generating a haptic torque based on vehicle lateral acceleration which is arranged to be subtracted from the torque assist signal such that when vehicle lateral acceleration builds up, corresponding to tighter cornering of the vehicle, the haptic torque subtracted from the torque assist signal increases the effective road reaction feedback sensed by the driver corresponding to the increase in cornering forces generated by the tyres of the vehicle.