Friction modeling and compensation for haptic interfaces

Friction cancellation and high gain force feedback are studied for their relative benefits in mitigating the effects of friction in haptic interfaces. Although either technique alone is capable of significant improvements, we find that a combination of approximate cancellation coupled with variable-gain low-bandwidth force feedback provides excellent friction reduction and is more robust. This improves the feel of the haptic interface, and provides significant linearization of the interface dynamics for more accurate model-based control.