A Position-Control Based Approach to Haptic Rendering of Stiff Objects

Conventional force rendering methods in haptic applications often suffer stability issues when simulating interactions with stiff objects such as a virtual wall. This paper argues that the emphasis in such scenarios is to minimize the penetration into the virtual wall instead of modeling the wall as a spring-damper system. Therefore, we propose an approach using a position controller to achieve better haptic rendering of the virtual wall. The proposed approach exploits model-based development tools to obtain the linear control system model without the need for an analytical model of the dynamics of the haptic device. A simulation-based performance comparison of two different controllers has been made for a 6-DOF parallel structure haptic device.