Abstract: In order to increase the accuracy of grinding large and medium scales aspheric surfaces, and increase the efficiency of fabricating aspheric surfaces, the error model of grinding axisymmetric aspheric surfaces is developed and the errors are compensated. Based on first-order linear model, a unified error model of aspheric grinding is derived by the utilization of the theory of multi-body system, and the transfer function of each error to the shape error is given. Based on centrally compensating the errors whose transfer function characteristics are similar, all trend errors are compensated by transforming them to the setting error and the wheel radius error, and a practical compensation model is presented, thus solving and correcting the specific errors is avoided. The error model and the distinguish model are proved by the results of the experiments, and the shape error will converge to the expected range. Thus the problem of accuracy control in grinding symmetry aspheric surfaces is resolved.

Key words: Aspheric grinding, Error compensation, Multi-body system theory, Shape accuracy