Applications of command shaping methods for reducing residual vibration in industrial servo systems

This paper presents an application of the command shaping method to industrial servo systems. The command shaping method, such as input shapers and bi-quad notch filters, is a well-known control technique for reducing residual vibrations. An input shaper cancels out the vibration using the convolution of a sequence of impulses with a reference command. A bi-quad notch filter places the filter zeros near the resonant poles of the closed-loop system and places highly damped filter poles. This paper compares the performance of three command shaping methods, which are zero vibration (ZV) input shaper, ZV and zero derivative (ZVD) input shaper, and a bi-quad notch filter. Numerical simulations are performed in various frequency ranges to measure the performance of the command shaping methods. Experiments are also performed using an industrial servo system to show that the command shaping methods successfully remove the residual vibration of the system, and have similar results for the various ratio of estimated frequency to actual frequency as in the numerical simulations.