Abstract: In order to improve the machining accuracy of cam grinding and solve the grinding accuracy problem of cam grinding system, the contour control strategy of cam grinding platform based on equivalent error method and B spline curve is put forward. By using B spline interpolation method, the motion command is given, and the lift data of the cam is processed by B spline inverse algorithm to obtain the control points of the generated sequence, to interpolate operation. Using the equivalent contour error as the object, the nonlinear equivalent error model of cam grinding system is established, such two axis tracking precision problems become equivalent error stabilization problems. And the control input value is calculated for compensation of contour error. In order to make the controller and the B spline curve design instruction compatible with Sylvester implicit method, B spline curve parameters are converted into algebraic form,
combined with the use of two methods to design the controller for high precision machining CNC cam grinding platform requirements. The proposed control strategy is demonstrated on the Sinulink simulation platform, It is proved that this method is feasible and effective, reduces the contour error and tracking error
of the system, and has good contour performance.

Key words: contour error compensation;Sylvester implicit, B spline curve, cam grinding, equivalent error method