ROBUST CONTROLLER DEVELOPMENT FOR A 3DOF ARTICULATED ROBOTIC MANIPULATOR USING H-INFINITY SYNTHESIS

SOURCE:

Faculty: Engineering
Department: Electronic And Computer Engineering

CONTRIBUTORS:

Agbaraji, E. C.
Inyiama, H. C.
Okezie, C. C.

ABSTRACT:

This researchwork focuses on robust controller development for joint torque control of a 3DOF articulated robotic manipulator under uncertainties. The articulated robotic manipulator dynamic model was achieved with decentralized (or independent joint) control approach, and the robust controller was achieved using H-Infinity(H∞) synthesis technique. The H-Infinitycontroller was compared with PID controller. From the results, at joint I, the H-Infinity controller recorded higher performance and robustness with peak sensitivity of 0.817dB, gain margin of 43.6dB, phase margin of 75.1degrees, steady state error of zero and overshoot of 0.62%, compared to the PID controller that recorded peak sensitivity of 3dB, gain margin of 20.4dB, phase margin of 60.1degrees, steady state error of 0.117 and overshoot of 7.27%.At joint II, the H-Infinity controller achieved better performance and robustness with peak sensitivity of 1.79dB, gain margin of 41.1dB, phase margin of 69.8degrees, steady state error of zero and overshoot of 1.17%, compared to the PID controller that recorded peak sensitivity of 1.86dB, gain margin of 37.9dB, phase margin of 69degrees, steady state error of 0.061 and overshoot of 1.86%. Therefore, from the results, it was concluded that H∞ controller guarantees more robustness with better disturbance and noise rejection characteristics, good performance and provides robust stability compared to the PID controller.