LPV modelling and identification of nonlinear temperature dependence for ultrasonic motor

This article deals with the linear parameter-varying (LPV) modelling methodology of the nonlinear temperature dependence of the ultrasonic motor. Prior to arriving at the LPV model, the temperature effect and subsequently the dynamic nonlinear model of the temperature dependence are deduced. Then the averaged pretreatment and the Jacobian linearization methodology are applied in sequence. The calculations, which are respectively obtained by the dynamic nonlinear model and the LPV model, demonstrated that the LPV model can be considered as an excellent alternative of the nonlinear model from the reconstitution of the dynamic behaviour viewpoint. The improvement of the widely-used frequency tracking scheme of the ultrasonic motor can be subsequently benefit from the proposed LPV, on the basis of which the stability analysis and the advanced model-based control algorithm design for the frequency tracking scheme will be realizable for the first time.