Design of Active Disturbance Rejection Control for Single-Link Flexible Joint Robot Manipulator

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 in terms 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 in system performance due to uncertainty in system parameters, 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.