Machining, Measurement, and Control Laboratory

Disturbance Estimation on a Hexapod-type Parallel Kinematic Machine Tool by Using a Disturbance Observer
Toshihiro Okuda (Kyoto University)
Soichi Ibaraki (Kyoto University)
Yoshiaki Kakino (Kyoto University)
Masao Nakagawa (Okuma Corp.)
Tetsuya Matsushita (Okuma Corp.)

On a contour-parallel tool path that is often used in die/mold machining, there are many regions where the tool is subject to a significant variation of cutting forces. In a finishing process, such a variation of cutting forces easily causes the degradation of machining accuracy and surface finish. This paper proposes algorithms to generate offset tool paths that maintain a constant cutting engagement in a 2-1/2 dimensional end milling. By maintaining the cutting engagement angle constant, the cutting force can be regulated approximately constant, which significantly reduces the variation of tool deflection, and then improves the machining accuracy. The validity of the proposed tool path generation schemes is investigated by machining experiments on hardened steel.
Key Words:   End milling, tool path, offset, contour parallel paths, cutting engagement angle, cutting force.