Parasitic effects of device coupling on haptic performance

The device dynamics of haptic systems play a crucial role in the performance of the human user. Typical operation of a haptic device during simulation requires the user to perform common tasks that constitute the bases for all user actions. These common tasks include manipulation, selection, and navigation. Navigation requires the user to transition the end-effector across regions of the device workspace moving to a new location of interest within the virtual scene. In this study we investigate the role that the inertia tensor coupling has on user performance during navigational tasks. We also adapt the operation and admissible-motion space representation for haptic systems in which forces causing deviations from a desired path can be thought of as parasitic forces that degrade a users performance. Dynamic simulations were carried out to gain insight into the effects of navigating along paths of varying coupling using a 2DOF five-bar mechanism and were experimentally validated with a Quansar 2DOF Pantograph device.