Haptic Rendering and Control

Abstract

Haptic algorithms compute forces from a virtual scene that are displayed via haptic interfaces to humans. This chapter focuses on suited algorithms and on control approaches for stable haptic interaction and highly transparent haptic rendering.<p> In haptic control systems, a fixed update rate is crucial for stability of the control loop. Thus, haptic rendering has to fulfil the requirement of deterministic computation time. Furthermore, high transparency requires high spatial resolution of the device's sensors and of the haptic algorithm. Haptic rendering based on the Voxmap-PointShell approach has the advantage of guaranteed update rates for collision detection and high resolution models, and is therefore suitable for haptic interaction.</p><p> Stability of haptic interaction limits the displayable stiffness of contacts in a virtual scene. Thus, a non-conservative stability condition is essential for high-transparent haptic interaction. The presented method is based on exact calculation of stability boundaries, which is in contrast to the widespread but conservative passivity-based approaches for haptic rendering.</p>