A new linear interpolation method with lookahead for high speed machining

To deal with inharmony between response frequency of servo system and signal output frequency of control system in high speed machining, a novel approach for linear interpolation with look-ahead algorithm was proposed. This approach was composed of two parts: look-ahead and tool-path resampling. In look-ahead control, the dangerous points on tool-path were found, and those relevant optimal velocities were estimated based on the response frequency of servo system ahead of machining. The optimal velocities of dangerous points would be later used for velocity arrangement to guarantee velocity smooth changing in machining. In tool-path resampling, tool-path was resampled in real time under the sample period of servo system to make signal output more harmonious. This approach has been tested in an open numeric control system based on PC. The velocity profiles show that this approach makes servo system and control system more harmonious in high speed machining.