Development of intelligent monitoring and optimization of cutting process for CNC turning

Abstract

In order to realize an intelligent machine tool, a system and procedures have been developed to optimize turning process for a CNC turning machine based on in-process tool wear monitoring and in-process chip breaking detection. A new quartz-type high-sensitive tool dynamometer is developed and implemented to the tool turret of CNC turning machine to monitor the turning process. In-process cutting force measurement is carried out to monitor the current amount of tool wear and the stability of the cutting process to check if broken chips or continuous chips are produced. Once the tool wear is estimated, the coefficients of the tool life equation are estimated or modified based on the estimated tool wear data by utilizing the least square method, and the cutting speed is optimized referring to the criterion of minimum production cost or maximum production rate.

The system developed is applied to actual turning of steel family with coated carbide tools, and it has been proved that the system runs satisfactorily. The method developed can be readily applied to unknown combinations of the work material and the tool as it searches the optimum cutting conditions automatically while the process is going on.

Keywords:

• Tool wear
• Tool life
• Cutting force
• CNC turning
• Optimization of cutting speed