Showing papers by "Xinkai Chen published in 1999"

Model reference robust control for non-minimum phase systems with disturbances

Abstract: In this paper, a new design technique of the model reference robust control is proposed for non-minimum phase (with respect to the relation between the disturbance and output ) continuous-time dynamical systems with disturbances. The designed controller requires only input and output measurements of the system. By using the estimate of a special signal generated by the disturbance, an intermediate control input is determined. Then, to assure the boundedness of the input and output, the model reference robust control input is designed to minimize the difference between the controlled system output and the desired output. Design example and simulation results are presented to show the practicality and effectiveness of the proposed algorithm.

Adaptive quasi-sliding mode control for discrete-time multivariable systems

Abstract: In this paper, the discrete-time adaptive quasi-sliding mode control for multivariable systems with perturbations and partial model uncertainties is studied. Even though no a priori knowledge of the perturbations is required, the dead-zone function is constructed based on the on-line estimates of the upper bound of the perturbations. By applying the adaptation algorithm with dead-zone, the unknown model parameters are estimated. Then, a discrete quasi-sliding mode adaptive controller with no chattering is synthesized to guarantee the global stability of the closed-loop systems in the sense that all signals remain bounded. If some information of the perturbations is known, the controller can be modified to improve the performance of the controlled systems. Examples and simulation results are presented to illustrate the proposed algorithms.

Vibration suppression control of flexible arms using sliding mode method

Abstract: The vibration motion of the flexible arm has an infinite number of modes. The higher order modes of the flexible arm are considered as the disturbances. Since the payload mass is usually unknown, the model uncertainties usually exist. The sliding surface is designed such that the dynamics on the surface are stable under the sliding mode control. The robustness of sliding mode control is effectively employed to compensate the model uncertainties and the disturbances. For different payloads, experimental results show that the robustness of the proposed method is superior to that of the traditional pole-placement methods.