| Based on a certain high precision rate servo system, the effects to the precision and smoothness induced with electromagnetic moment fluctuation of the motor is emphasized and analyzed in this paper. The static performance of the system is improved by controller design.Firstly, the mechanism model of permanent magnet synchronous motor with vector control is derived by completely decoupling; and so on the mathematics model of the plant. The nominal plant is given by the method of least squares in frequency domain. The principle of the motor moment fluctuation subjected to periodical disturbance in rate table servo system is analyzed. The quantity and mathematic expression of the moment fluctuation are presented by experimention. Secondly, The design problem of continuous repetitive control system is studied. the basic theory of the repetitive control is introduced.Thirdly, based on the detailed analysis and discussion of the controller structure, stability and other performances of the RC systems, the design index reflecting the trade-of of steady-state accuracy and transient response property is determined and a design method for plug-in systems is proposed. The above method provides a feasible control strategy for the further improvement of the performance of the system.At last, design the controller for the fact object. firstly, using the changed step methods to obtain the speed signal, then design the speed loop controller and position loop controller, at last design the plug-in repetitive controller, the result of the simulation the fluctuating moment is good restrained. |
