Research On Intelligent Modeling And Resonance Suppression Of Servo System

With the development of industry of mechanical and electrical manufacturing,modern computer technology,power electronics technology,microelectronics technology and modern control theory,servo system with AC motor as the driver developed greatly.Servo system usually needs mechanical transmission to carry the load.Mechanical transmission includes ball screw,linkage rod,pulley,etc.The mechanical transmission is generally considered as an ideal rigid body.Due to the existence of elastic deformation,there will be resonance phenomenon.Therefore,the mechanical transmission can not be equivalent to an ideal rigid body.To guarantee the closed-loop performance of the servo system while restraining the resonance phenomenon of the system is a worthy thorough research problem.In this paper,the permanent magnet synchronous motor(PMSM)servo system is introduced.PMSM is modeled and analyzed.For the convenience of calculations,the servo system is simplified into a motor-spring-load two-mass system.Then the two-mass system is modeled.The resonance phenomenon is analyzed from mechanism.Considering the effect of friction of the servo system,friction mechanism is analyzed.The friction model is identified by using the least square method and the fitting method based on the BP neural network respectively.The simulation shows that the effect of friction on the system can be effectively suppressed after compensation.The designed detection signal is used to test system.The resonant frequency of the system is obtained by using method of direct analysis and fitting method of the transfer function.The comparative analysis shows that a more accurate system model can be obtained by friction compensation.The traditional notch filter can deteriorate the dynamic response characteristic of the system at the point of resonant frequency in the case of suppression of resonance.In order to suppress resonance,the resonance suppression method based on an improved notch filter is proposed.Through comparison and analysis,it can be seen that the improved notch filter is effective in suppression of resonance.