Closed-Loop Force Control for Haptic Simulation of Virtual Environments

Abstract

This paper investigates the use of force control for improving haptic force feedback used in virtual reality simulations. Advances in control system design will help increase the fidelity of the haptic feedback thus giving operators a more realistic interface for simulation and training. The classic haptic controller with model feedforward is first described along with its inherent limitations. Modified approaches which use force control are then investigated and the resulting improvement in haptic resolution discussed. An example using a four-bar linkage is used to illustrate the fidelity of the haptic interface obtained using the classic versus force-feedback approaches. The tradeoffs entailed in going to force feedback controllers for haptic applications are also discussed.