Robust joint-model-based control for constrained robots

Most existing approaches so far on position/force control of constrained robots always suffer from the complexity of the arm model that may cause difficulty in practical application. In this paper, a robust joint-model-based controller is proposed to deal with the problem of hybrid position/force control for constrained robots. The development of the controller is based on a novel formulation of the joint dynamic model and a combination of nonlinear state transformation and sliding mode method. The proposed controller possesses not only the sliding mode control like robustness but also the independent joint control like simplicity. In addition, it can be easily implemented. To evaluate the control performance, the proposed controller is applied to a two-link constrained robot through simulations. Comparing with some existing approaches based on arm model, the simulation results indicate that the proposed scheme can achieve similar and satisfactory control performance.