PID position control for 2-DOF robotic finger

This paper presents the evaluation of motor performance for different loads, PID tuning and evaluation of the new PID values for a two degree of freedom (DOF) robotic finger. The prototype 2-DOF finger which has been developed in a separate study has two joints and two links, and is made of prospective plastic material. The control system comprises of two DC-micromotors, magnetic encoders, a motion controller unit and a PC. Initially, an experiment to observe the effect of different loads to the motor is implemented. The observation is then used for the PID controller tuning to improve the position control performance in terms of the overshoot, rise time, peak time, settling time and the error. Next, the evaluation of the position control with the new PID parameters is implemented to the robotic finger for continuous motions of the motor at three different positions. Motion manager software provided by the Faulhaber Company is used to obtain the encoder measurement for the motor position and to execute command to run the motor. From the experimental data, it can be observed that with the new controller parameters the performance of motor has shown improvement for both robot joints. This proves that the efficiency of motor control is an important element for developing robotic finger for performing task at high precision standard.