5-axis polynomial spline interpolation in an open CNC system

Using the advantage of polynomial spline interpolation to represent spatial curves with good approximation effect and mature technology, an instruction format with polynomial spline curves, which is suitability for five axes coordinated real-time interpolation, is presented against the current five axes coordinated linear interpolation method with drawbacks of low-speed, low-accuracy and great NC files in sculptured surface machining. Structure of the controller of an open CNC system developed by ourselves is introduced. And the method to realize the interpolation in translator and interpolator is further discussed detailedly. Through the illustration, it has been indicated that the proposed method can avoid all the shortages of five-axis linear interpolation method. The preliminary application results show that the said technology has a better suitability.