Bio Inspired Modified Internal Model Control Approach for Improved Disturbance Rejection of Piezo Micro Manipulator

摘要

Classical Internal Model Control based approach for controller design has been used in different industrial control applications as it allows good set point tracking performance, especially for processes neglecting time delay. However, in many process control applications including nonlinear piezo electric actuation (PZA), disturbance rejection plays an important role compared to set point tracking. The present research firstly proposes an optimal filter design in series with a Modified Internal Model Control (M-IMC) based Proportional - Integral-Derivative (PID) controller for better set point tracking, improved disturbance rejection with reduced controller hardware resource requirement compared to classical IMC. Two efficient swarm intelligence based evolutionary soft computational techniques viz. Particle Swarm Optimization (PSO) and Bacterial Foraging Optimization (BFO) are then exploited towards optimizing a control evaluation index based fitness function to design the M-IMC control parameters, including filter time constant. The distillation of bio inspired principles in control is seen to exhibit exciting results when the optimized parameters are utilized in the piezo plant modeled using a Dahl based second order system. The performance of the controller has been evaluated by subjecting the plant to several perturbations as well as to external disturbances. The results illustrate the efficiency of the PSO based M-IMC over other controllers.