Patent ID: 7750593

Claim:
An active human-machine interface system, comprising: a user interface configured to receive user input and, upon receipt thereof, to move to a position; a position sensor coupled to the user interface, the position sensor operable to sense user interface position and supply a position signal representative thereof; a motor coupled to the user interface, the motor further coupled to receive motor current and operable, upon receipt thereof, to supply a feedback force to the user interface at a magnitude proportional to the motor current; and a control circuit configured to control the motor current supplied to the motor, the control circuit comprising: a counter coupled to receive the position signal and operable, in response thereto, to supply an absolute position signal representative of user interface absolute position, a force versus position determination function coupled to receive the absolute position signal and operable, in response thereto, to supply a force feedback signal representative of the feedback force, a differentiator coupled to receive the absolute position signal and operable, in response thereto, to supply a velocity signal representative of a rate of change of the absolute position, a damping factor function coupled to receive the velocity signal and operable, in response thereto, to supply a damping factor signal representative of a damping factor, a motor current command function coupled to receive the force feedback signal and the damping factor signal and operable, in response thereto, to supply a motor current command signal, and a commutation control function coupled to receive (i) the position signal, (ii) the signal representative of the motor current, and (iii) the motor current command signal and operable, in response thereto, to supply the motor current to the motor.