Robust neural force control with robot dynamic uncertainties under totally unknown environment

In this paper, a robust robot force tracking impedance control scheme that uses a neural network as a compensator is proposed. The proposed neural compensator has the capability of making the robot track a specified desired force as well as of compensating for uncertainties in environment location and stiffness, and the uncertainties in robot dynamics. The neural compensator is trained separately for free space motion and contact space motion control using two different training signals. The proposed training signal for force control can be used regardless of the environment profile in order to achieve desired force tracking. Simulation studies with three link rotary robot manipulator are carried out to demonstrate the robustness of the proposed scheme under uncertainties in robot dynamics, environment position and environment stiffness. The results show that excellent force tracking is achieved by the neural network.