An interpolator is an essential component in CNC machines that generates commands for tool motion. Increasing demands on precision in machinihg of free-form contour have necessitated the tool to move not only with position error as small as possible, but also with smoothly varying feedrates.
In this research, a system which interpolates and machines of a contour consisted of line, arc and spline elements with reference-pulse interpolation technique was developed using personal computer. Through the comparing of previous method of interpolation, M_SAM and M_DSM which have advanced efficiency were developed. Using Ferguson curve fitting, spline interpolator was designed to follow the curve. To apply to real cutting process, constant feedrate compensation and acceleration-deceleration compensation were conceived. And using retrofitted milling machine, performance of interpolator was tested.
Results show that the interpolator is favourable in the machining of free-form geometry in terms of tight tolerancing.
