Sensorless Reaction Force Estimation of the End Effector of a Dual-arm Robot Manipulator Using Sliding Mode Control with a Sliding Perturbation Observer

We estimated the reaction force for assembly work with a three-link dual-arm robot manipulator using sliding mode control with a sliding perturbation observer (SMCSPO) without using a force sensor. The sliding perturbation observer (SPO) is used to estimate the reaction force of the end effector without using any sensor. The SPO estimates the perturbation, which consists of the parameter uncertainties, nonlinear terms, and disturbances such as the reaction force. During assembly, the most effective perturbation term is close to the reaction force, so we assumed that the estimated perturbation is the same as the reaction force. The estimated perturbation was compared with the reaction force from the dynamics of the manipulator using a simulation with the SimMechanics toolbox of MATLAB/SIMULINK. The simulation results show the performance of the SMCSPO and that the reaction force can be estimated using the SPO without any sensor. The method can improve the structural reduction of link manipulator robots and decrease costs.