Design of a haptic display for interacting and sliding on deformable objects

We present a stable and robust point-based haptic rendering methods to interact with various types of deformable elastic object, from (soft) low-stiff to (rigid) high-stiff, using control algorithms. The proposed method offers a high-fidelity 3D force reflecting haptic model to guarantee a stable sliding and force (feedback) field over the surface of polygonal-based deformable bodies with different normal stiffness in each triangle mesh. Control algorithms are examined to maintain and to improve the stability margins and achievable performances for the haptic display with force continuity. Two classes of control strategies are investigated. The first is a lead-lag (L-L) compensator designed based on classical control and the second scheme is a linear-quadratic-Gaussian (LQG) controller designed from modern control theory. Detailed comparison and evaluation of the proposed methods are presented to illustrate the performance of the haptic display when applied for deformable objects.