Gain adaptive nonlinear feedback control of flexible SCARA/Cartesian robots

This paper presents a class of gain adaptive nonlinear feedback control for flexible SCARA/Cartesian robots. The controller is constructed by using vibration related nonlinear variables feedback and at the same time automatically tuning the feedback gains. Firstly, the closed-loop stability is proven for the original distributed-parameter system. Then, through explicitly solving the Partial Differential Equations (PDEs) of the system, asymptotic stability is obtained for the undamped truncated system, in which the distributed flexibility of the robot link is represented by an arbitrary finite number of flexible modes. Due to the non-model-based nature of the controller, some favorable features appear such as the elimination of control spillover and simplicity of actual implementation. Computer simulations are provided to illustrate the effectiveness of the approach.