Design of a Compact 6-DOF Haptic Device to Use Parallel Mechanisms

We present design of a compact haptic device in which parallel mechanisms are utilized. The design realizes a large workspace of orientational motion in a compact volume of the device. The device is a parallel-serial mechanism consisting of a modified DELTA mechanism for translational motion and a spatial five-bar gimbal mechanism for orientational motion. We derive an analytical model of stiffness for the modified DELTA mechanism which we utilize for the design of a stiff platform for translational motion. The model shows that the compliance matrix is a function of kinematic parameters as well as elastic parameters of each mechanical element. Configuration dependency of the compliance matrix is therefore an important point to be noticed.