Design of a Torque Controller with Application to a Single Degree of Freedom Haptic Device

The main aim of the work is to design a torque controller which is a critical element in a haptic device. Since, the torque is related to the current in a DC motor, the paper comes up with a current control circuit by which current can be controlled across a branch in the circuit. From experiments, an empirical current–torque relationship is obtained for the DC motor using a constant current power source. The DC motor is then integrated with the current control circuit so as to generate a theoretical relation between the voltage of the current control circuit and the torque of the DC motor. This theoretical voltage–torque relationship is also validated experimentally. The working of the entire set-up with reference to a single degree of freedom haptic device is also explained. The proposed work would draw the attention of more researchers for the development of affordable haptic devices.