Abstract
Deformation of a machining system due to machining force is a major cause of decrease in product preciseness. Generally, to increase the preciseness, rigidity of frame, chuck and tool of the machining system is to be reinforced. This induces increase of size, mass and complexity of the system. The authors propose an another approach. By employing a negative compliance device, it is possible to compensate deformation of the machining system caused by machining force. In this paper, a machining system with the negative compliance device is analyzed. Control conditions for stabilization and compensation are shown. A 3-axis negative compliance system is realized by using a ring-shaped active force sensor. To confirm reduction of machining error, the negative compliance system is applied to a face grinding machine of silicon wafers. Through experiments of grinding wafers, it is confirmed that the error can be reduced from 0.9μm to less than 0.1μm with cutting depth of 10μm.
