Research on Contact Force Tracking of Robotic Manipulators Based on Active Disturbance Rejection Control

The research importance on the robot contact force tracking has been increasing recently due to a need for robots to interact more with the outside world. However, the traditional impedance control cannot avoid transient contact force overshoots and steady-state force tracking error, and take uncertain disturbance into account sufficiently. To address these problems, this paper proposes a strategy for contact force tracking of robotic manipulators based on active disturbance rejection control (ADRC). Firstly, the contact force dynamic between robotic manipulator and the surrounding environment is described as the (nonlinear) Hunt-Crossley (HC) model, rather than the classical (linear) Kelvin-Voigt (KV) model. Secondly, the transition process of contact force is designed for overcoming the defect of excessive instantaneous contact force. Finally, a compliance control based on ADRC is proposed to suppress disturbance forces and ensure the force tracking performance. The simulation results show the correctness and effectiveness of the presented scheme.