Study On Typical Nonlinear Inverse Compensation Strategy Of Mechanical Transmission System

In the mechanical transmission system,there are a wide range of nonlinearities,such as backlash,dead-zone,friction and saturation,etc.,in which the backlash nonlinear and dead-zone nonlinearity are the most important and most common nonlinear.These non-linearities severely affect the performance of system control.Therefore,it is of great theoretical and engineering significance to conduct an in-depth study of these nonlinearities existing in mechanical systems.In this paper,typical backlash nonlinearity and dead-zone nonlinearity exist in mechanical system as the research object.Pointing at these nonlinear compensation control strategies,the control scheme is proposed: for the backlash nonlinearity,a fuzzy PID inverse compensation control scheme is proposed by establishing its inverse backlash model;for the dead-zone nonlinearity,by establishing the mathematical model between the nonlinear characteristic and the input signal frequency,the influence of nonlinearity is restrained by the method of inverse compensation.The main work of the dissertation is as follows:1.The linear description of the mathematical model of the backlash nonlinearity is studied.By introducing the switching function,the model mechanism is improved,and the system is described as linear.This provides a basis for the identification of the backlash nonlinear coupling to other dynamic systems,and simulates the backlash parameter identification experiment.2.For backlash coupling and linear systems such as Hammerstein systems with backlash,using the linearization method proposed in this paper,the entire system is modeled as a linear model,and the parameters of the system are identified using a recursive least squares algorithm,the Hammerstein system parameter identification with backlash is realized.3.For a class of Hammerstein systems with backlash,the effect of the gain ratio in the linear dynamic subsystem on the identification and control of the whole system is studied.And for such systems,a fuzzy nonlinear PID-based backlash compensation control method is proposed,designing simulation experiments proves the effectiveness of the scheme.4.The problem of identification and compensation of the dead-zone nonlinearity caused by the starting frequency is studied.To stepper motor-driven three-axis slide transmission system,for example,Through the method of system identification,the mathematical model between nonlinear characteristic and input signal frequency is established,The use of inverse compensation method to suppress the adverse effects of its nonlinear.