In recent manufacturing process, the increase of productivity is required by reducing machining time with the increase of cutting force. However, the excessive increase of cutting force results in the tool breakage, having a bad effect on both manufacturing machine and workpiece. Thus, it is necessary to estimate and control cutting force in real time during the process. In this study, disturbance observer is developed for the indirect cutting force estimation. The estimated cutting force is used for the real tine control of feedrate, making the actual cutting force follow the reference force. The suggested method has no need for the expensive sensor like a dynamometer, so practicality and common use are expected. By reducing the machining time resulting from making the actual cutting force follow the reference force, the increase of productivity are also expected. Besides, an actual constant cutting force guarantees the prevention of tool breakage. To show the effectiveness of the suggested cutting force control method, an experimental setup has been made without sensor, applied to several workpieces. Experiments show that the suggested method is superior to the conventional method operated by constant feedrate.
