Precision contouring control of machine tools

Computer numerical control (CNC) machines are now widely used in the manufacturing industry. There is an increasing need for lower-costing machines capable of high precision machining. To achieve high precision machining, the motions of the axes of these machine tools need to be controlled precisely so that they follow a desired path, or contour, accurately. This paper discusses some of the factors that can affect the accuracy of the contour generated. Also discussed are some compensation approaches to compensating the geometrical errors of these machines so as to achieve precision results even with not-so-accurately build machines. Also presented and discussed are the results of approaches taken in improving contouring accuracy through the design and tuning of the machine axis controllers as well as some contour path compensation approaches.