Research And Application Of GIMC Algorithm In Motion Control System

Keeping good performance in the event of model uncertainties or external disturbances is crucial in many industrial applications, especially if costly equipments are controlled. So a fundamental reason for using feedback control is to achieve desired performance in the presence of external disturbances and model uncertainties. It is well known that there is an intrinsic conflict between performance and robustness in the standard feedback framework. In other words, one must make a tradeoff between achievable performance and robustness against external disturbances and model uncertainties. H∞control, L1 control,μsynthesis, etc, have gained popularity in the last twenty years or so. Unfortunately, it is well recognized in the robust control community that a robust controller design is usually achieved at the expense of performance. This is not hard to understand since most robust control design techniques are based on the worst possible scenario which may never occur in a particular control system.In this thesis, we propose a new high performance, robust, and fault-tolerant feedback controller architecture—GIMC(Generalized Internal Model Control). The controller architecture includes two parts: one part for performance and the other part for robustness. The controller architecture works in such a way that the feedback control system will be solely controlled by the performance controller when there is no model uncertainties and external disturbances and the robustification controller will only be active when there is model uncertainties or external disturbances. It completely overcomes the conflict between performance and robustness in the traditional feedback framework.Totally speaking, the thesis includes the following parts:(1) The Youla parameterization is given in detail, which provides essential theory foundation for the GIMC controller architecture.(2) The GIMC controller architecture is given.(3) Using robust control theory, the stability of the GIMC controller is proved. Also some simulation results prove that.(4) The GIMC controller is implemented in motion control system. And numerical simulation results show its efficiency and feasibility.By concluding this dissertation, the next research works are given.