Robotic Arm End-Effector Reaction Force Estimation for Part Assembling Process Using Sliding Perturbation Observer

This paper presents the end-effector reaction force estimation algorithm for dual robotic manipulators used for the parts assembling process. The Assembly process requires a robust tracking controller to operate precisely. And to avoid any possible damage while assembling process, the end-effector force should be considered. Due to the inherent limitations of the system, a force sensor cannot be used. Therefore, a non-linear estimator known as a sliding perturbation observer (SPO) is used. SPO estimates the perturbation (non-linearities, uncertainties, and disturbances) of the system even without correct information of system dynamics. The end-effector force was considered as an external disturbance to the system, which is then estimated based on the relation with perturbation from SPO. For position control of the robot, the sliding mode controller was integrated with SPO to make a robust controller (SMCSPO). The algorithm was implemented and validated on the virtual prototype of the existing dual 7-DOF robotics arms system in MATLAB/Simulink.