Extended State Observer based robust control of electrically-driven modular manipulator

Based on Extended State Observer (ESO), a new robust control strategy with backstepping design for modular manipulators is brought forward in this paper. Firstly, considering the motor dynamics of the robot manipulator, the robot manipulator dynamics can be separated into two subsystems named as the robot joint subsystem and the motor subsystem. Then, a third-order and a second-order ESO are respectively designed for these two subsystems. With uncertainties in both subsystems approximated by the extended state, the virtual control force and the real control input voltage of the system can be designed based on Active Disturbance Rejection Control (ADRC) method. The proposed approach only rely joint position messages without velocity measurement. Further simulation results of joint space trajectory tracking on a modular manipulator are presented to validate the design.