Linear and Nonlinear Active Disturbance Rejection Controllers for Single - Link Flexible Joint Robot Manipulator based on PSO Tuner

Abstract

This work presents the design of active disturbance rejection control (ADRC) strategy to position control of a single-link flexible joint robot manipulator. Two schemes of ADRC are presented, Linear Active Disturbance Rejection Controller (LADRC) and Nonlinear Active Disturbance Rejection Controller (NADRC). A comparison study of transient performances, robustness characteristics and disturbance rejection capabilities has been made based on LADRC and NADRC. The robustness of both controllers is evaluated by measuring the amount of deviation is system performance due to uncertainty in system parameters, while the disturbance rejection capability of both controllers will be investigated under abrupt disturbance exertion. One issue with NADRC and LADRC is they include various parameters and unless they are properly tuned, will have an adverse effect on the estimation process and in turn, on the system performance. The particle swarm technique (PSO) has been selected as an optimal tuner to improve the estimation process and thereby, to enhance the system performance.