Tracking Control Performance of a 2-DOF Robotic Finger using PID and LQR Controller

This research focuses on the tracking control performances of two degrees of freedom (2-DOF) robotic finger mechanism in achieving precision motion control as initial research towards developing a multi-fingered robotic hand system. Behaviors such as instability, large steady-state error and poor transient performance often occurred in the robotic hand mechanism. In this research, the proposed controllers will depend on the angular position control of each motor joints, i.e. the position control of the 2-DOF robotic finger mechanism. Two control strategies namely (i) Proportional Integral Derivative (PID) controller and (ii) Linear Quadratic Regulator (LQR) controller were chosen to be compared via simulation and experimental works. The controller results were validated by tracking control with frequency from 0.1 Hz to 0.5 Hz at different reference amplitudes. From the analyze results, it was concluded that LQR controller exhibits the best tracking control performances. The LQR controller had demonstrated an improvement in steady-state error by 98.5 % (0.11 degrees) in a series of experimental tracking tests.