Vibration Rejection Scheme of Servo Drive System with Adaptive Notch Filter

The servo drive system using PMSM (Permanent Magnet Synchronous Motor) and ball-screw, gear, timing-belt are widely used in industrial applications such as NC machine, machine tools, robots and factory automation. These systems have torsional vibration in torque transmission from servo motor to mechanical load due to the mechanical couplings. This vibration makes it difficult to achieve quick speed responses and may result in damage to the mechanical plant. This paper presents adaptive notch filter with auto searching function of vibration frequency to reject the mechanical vibration of linear feeder system with PMSM. The proposed adaptive notch filter can suppress the torque command signal of PMSM in the resonant bandwidth to reject the mechanical torsional vibration. However, as the resonant frequency can vary with conditions of mechanical load and coupling devices, adaptive notch filter can auto search the vibration frequency and suppress the mechanical resonant vibration consequently. Experimental results show the verification of the proposed adaptive notch filter in linear feeder system.