Control methods for the reduction of limit cycle oscillations for haptic devices with displacement quantization

Abstract

Systems and methods for reducing limit cycle oscillations of a haptic device. A net force applied to the device is a combination of a primary force computed in a main haptic loop and a secondary force computed in a damping loop that cancels or minimizes the oscillations. Various algorithms for computing the secondary force are provided. In one algorithm, the secondary force is determined from the momentum error associated with crossing of a wall position by the manipulandum and is applied immediately after the crossing is detected. In another algorithm, a periodically varying secondary force with a phase shift relative to the phase of the oscillating manipulandum is computed.