Mechanical Resonance Modeling and Forecasting in Servo Systems Based on Vector Fitting

The transmission mechanisms in servo systems have finite stiffness, therefore the elastic deformation and the rotary inertia would cause mechanical resonance in servo systems. Based on the theoretical analysis of the mechanical resonance, the quantitative relation between transfer function of the resonance and system parameters (including torsional elastic coefficient and load rotary inertia) is built. In this paper, the rational approximation of mechanical resonance amplitude frequency characteristics is calculated by vector fitting method in the presence of known system parameter. With different given system parameters, the nonlinear mapping between system parameters and the transfer function of mechanical resonance through sample training is established through sample training. Therefore, the effective prediction of the transfer function of mechanical resonance with regards to the variation of servos conditions can be realized.