Suppression of servo system mechanical resonance based on adaptive IIR notch filter

In actual servo system, the transmission mechanism is not an ideal rigid body, and mechanical resonance easily occurs. In this paper, the transmission mechanism of servo system is equivalent to a torsion spring, and the entire flexible connection servo system is simplified into a motor-spring-load two-mass system, then the mathematical model of the flexible connection servo system is established through theoretical analysis. Since the mechanical resonant frequency of the system will change with time and environment, the parameters of notch filter must be adjusted online with the resonant frequency. In this paper, according to the application requirements of mechanical resonance online suppressing, the mechanical resonance online suppressing algorithm based on adaptive IIR notch filter is proposed. Using a recursive least squares algorithm, resonant frequency of the system is online estimated, and then the frequency parameters of notch filter are adjusted online. The simulation results show the effectiveness of this method.