Design optimization of the Tau haptic device

The work presented in this paper is motivated by the use of haptics in medical simulation, particularly simulation of surgical procedures in hard tissue such as bone structures. In this context, characteristics such as motion, stiffness, workspace-to-footprint ratio, and low inertia are key factors in the design of a haptic device. This paper introduces a procedure for design optimization of haptic devices based on a hybrid mechanism. For design optimization, performance indices such as workspace volume, kinematic isotropy and static torque requirements indices are defined. A new multi-criteria objective optimization (MOO) function is introduced to define the optimization problem. Multi-objective algorithms are used to solve this optimization problem using the defined objective function. Furthermore sensitivity analysis of the performance indices against each design parameter is presented as a basis for selecting a final set of design parameters to develop a prototype. Finally, a CAD model and prototype of the device is developed based on the simulation results.