Robot Arm End-Effector Force Tracking Impedance Control with Sliding Perturbation Observer-Based Estimated Environment Force

Abstract

The design of a controller for a robotic manipulator is a crucial step in achieving system robustness, accuracy, and stability. When the robot manipulator comes into contact with the environment, it becomes vital to establish a controller structure that prevents damage to both the manipulator and the environment. This paper presents a robot manipulator end-effector force tracking impedance control, primarily relying on a non-linear observer called the sliding perturbation observer (SPO). The SPO estimates system perturbations and compensates for their effects on the system's response. By utilizing the SPO, the applied force on the environment is estimated. An impedance model based on a PID controller is employed for force tracking, resulting in the generation of a compliant end-effector trajectory aligned with the desired force. Subsequently, a joint trajectory is generated to achieve position control. To attain robust joint trajectory tracking, a PID controller is integrated with the SPO for position control. The control algorithm is implemented and designed in the MATLAB/Simulink environment. The simulation results effectively demonstrate the efficiency of both impedance and position control.