High speed contouring control strategy for five-axis machine tools

Accurate contouring of five-axis tool-paths with CNC machine tools is important in high speed machining of dies, molds and aerospace parts having sculptured surfaces. This paper presents a new control approach where all five drives of the machine tool are controlled simultaneously with an objective of minimizing contouring errors. Contouring errors are estimated analytically from differential path geometry and the kinematics of the machine. A multi-input multi-output (MIMO) sliding mode controller is designed to control three Cartesian and two rotary drives simultaneously with kinematic coupling. Experimental results show that contouring errors o are reduced significantly by controlling all five drives simultaneously.