Modeling and robust control of two-link planar nonlinear robotic systems

The paper first develops a new detail modeling of twolink planar nonlinear robotic systems for model-based manipulator control systems. The new model is practical by considering not only the robot arm joint mass, but also the robot arms distributed mass. By a special case of the new model, it also corrects an error of the common model with the joint mass only in the literature. Furthermore, in view of numerous uncertainties, the paper presents a robust control with pole clustering for the robotic systems with this new detail modeling. The designed robust control law provides an H∞ disturbance rejection by a prescribed attenuation index δ. Moreover, the designed robust control law guarantees designed closed-loop system poles robustly located in a vertical strip on the left-half complex plane in face of the parameter errors and state-dependent perturbations. Thus, the designed robust control system has robust stability and robust pole clustering. Two examples demonstrate the results. The new results may be used in practice.