Non-Linear muscle-like compliant controller

A compliant controller for an actuator that does not require the use of a force sensor comprising:

• a position sensor for sensing the position of the actuator to generate signals representing actuator position;
• a processor responsive to sensed actuator position and operating in accordance with a force determining algorithm that is a function of an initial actuator position, a subsequently sensed actuator position and a position calculated from a nonlinear damping function to determine an actuating force, the actuating force being nonzero in the presence of a disturbing force, the processor comparing the difference between an initial actuator position and a subsequently sensed actuator position to a value representing a predetermined amount of movement, the processor resetting the calculated position to a predetermined value if the difference is less than the predetermined amount of movement to reduce the actuating force in the presence of a disturbing force and the processor setting the initial actuator position to the subsequently sensed actuator position if the difference is greater than the predetermined amount of movement.