Two-degree-of-freedom robust control with applicantion in the non-circular turning

A method combining zero phase error tracking based feed forward control with two-degrees-of-freedom H∞ robust control is proposed for the linearization control of piezoelectric translator (PZT) and used in the control process of piezoelectric translator during the non-circular turning. Large phase error of input and output produced by its non-linear feature is reduced and system dynamic performance is improved when the influences of the uncertainties of parameters perturbation and load disturbance is overcame. As the precise mathematic model of PZT is hard to get, the linear model is used for the control convenience. The performance of accurate tracking and disturbance rejection is manifested through zero phase error tracking based feed forward controller and H∞ robust controller. Analysis of sensitivity function of the system, simulation and experiments show that the control structure can achieve good tracking accuracy and robustness.