Mechanical Resonance Suppression Of AC Servo System With Flexible Load

In AC servo system,Mechanical transmission mechanism is often used as connection device.But transmission device has flexible in real system.The mechanical resonance phenomenon is generated because of importing of flexible load.In this paper,the status and existing problems of the mechanical resonance in the servo control system at home and abroad are described firstly.In order to analyze the cause of the mechanical resonance,the mathematic model of servo system with 2-mass is established.The relationships between the resonance characteristics of mechanical transmission part and servo system performance are discussed.Then,the effects of inertia ratio,stiffness and viscous damping coefficient of mechanical transmission on system performance are analyzed in detail.Secondly,in order to achieve accurate and fast detection of mechanical resonance frequency,the frequency detection method based on ANF algorithm is introduced,and the influence of different parameters on the detection results is analyzed.and compares it with traditional fast Fourier transform.Simulation and experiment of the two methods verify that the ANF is effective to detect resonance frequency.Next,aiming at the phase lag caused by traditional notch filter of the mechanical resonance suppression of servo system.The principle of mechanical resonance of the servo system and the phase characteristics of traditional second-order notch filter were studied.The influence of notch filter on the system was analyzed.In order to decrease the phaselag,an improved notch filter was proposed based on traditional notch filter.The resonance suppression of servo system based on improved notch filter was designed.The simulation and experimental results indicate that the improved notch filter get smaller phase lag,and the system bandwidth is expanded compare with the traditional notch filter.Finally,the experiment platform of servo system with mechanical resonance is set up,and we apply those methods to the servo system,and the experimental results sufficiently show that this proposed strategy is very feasible and effective.