Robust Control Of Dual Position Loops Linear Servo Synchronized System

The background of this dissertation is the gantry synchronous control problem of numerical control gantry-moving type milling machining center drived by two linear permanent magnet synchronous motors with the same parameters. Theory of dynamic precision synchronization traverse and research of realization methods for linear servo dual position loops system is researched. This paper presents robust control method for linear servo dual position loops system. The research of this problem has an important and pervasive significance for solving multitude motors high precision feed and synchronous control. The research of the paper is based on three aspects: standard H∞. control, H∞ self-tuning regulator conirol and robust H∞ control.Standard H∞ control: Because standard H∞ control has a strong restrain for loaded disturbance, it is applied for control of servo system. This paper will design an H∞ robust controller to be used acceleration state feedback, control, or, furthermore, both speed and acceleration state feedback control, which can rapidly restore synchronous state under the condition unbalanced loads or uncertain disturbances. The result of acceleration, speed and position dynamically synchronized control is achieved.H∞ self-tuning regulator control: Although standard H∞ control has a strong restrain for uncertainly loaded disturbance, it can not guarantee a good robustness for uncertain parameters therefore H∞ self-tuning regulator control is used in this system. When unknown and bounded disturbance, parametric uncertainties and unmodelled dynamics exit at the same time, the system will automatically tune regulator parameters so as to guarantee robustness of speed synchronized control system and achieve indirectly position synchronized control.Robust H∞ control: This paper presents robust H∞ control for linear servo system with uncertainty. First, the problems of design of robust H∞ controller for time-varying parameters system with uncertainty is converted into a standard H∞ control problems of linear time-invariant parameters system with an equivalent and not included anyparameters uncertainty. Then, a controller, for standard H∞ control problems, is obtained through solving an algebraic matrix Riccati equation with symmetrically positive solution, namely, robust H∞ controller for system with uncertainty. The linear servo system with robust H∞ controller not only can guarantee a good resistance for loaded disturbance but also can satisfy robustness for uncertain parameters.Both theory analysis and results of simulation test indicate that the proposed scheme has a satisfied control effect and strong robustness, and that meets demand of speed synchronized control as well as position synchronized control for boring-milling machining centers of gantry-moving type. Moreover, these aspects are also original works.