Synthesis of Two Degrees-of-Freedom Haptic Device

Haptic devices are force-feedback devices that mediate communication between the user and the computer. Such devices allow users to touch, feel and manipulate threedimensional objects in virtual environments and teleoperated systems. In this paper, one such device is synthesized for the purpose of training medical students and professionals, specially those requiring force-feedback from the virtual needle inserted into the body. The device is designed to deliver high force. Kinematic analysis of a suitable mechanism is performed and singularities in its workspace were identified to form constraints for an optimization. Performance index based kinematic optimization of the mechanism was performed over the whole workspace. The performance was then checked and limitations were analyzed by means of the so called force manipulability ellipsoid. We found that the performance in terms of kinematic singularity was greatly improved for the optimized mechanism.