DESIGN AN OPTIMAL PID CONTROLLER WITH NONLINEAR FUNCTION USING BACTERIA FORAGING OPTIMIZATION FOR SINGLE FLEXIBLE LINK ROBOT MANIPULATOR

This paper presents an optimal design of a modified Proportional Integral Derivative (PID) controller with nonlinear signum function for vibration control of a single-link flexible manipulator system. This manipulator is a Single Input Multi Output (SIMO) system with applied torque as the input signal, and the hub angle and tip deflection as the outputs. The dynamic model of the flexible link system is represented by finite element method. The Bacteria Foraging Optimization (BFO) algorithm is used to tune the parameters of the PID controller. A nonlinear signum function is added to improve the performance of this controller. Different types of inputs are tested with different payloads to illustrate the robustness of the control scheme. The scheme successfully reduces the effect of the vibration and minimize it to zero at the tip-end, even with payload variation.