The real-time error compensation technique for CNC machining systems

One of the important trends in precision machining is the development of real-time error compensation technique. This paper presents the research work under the authors and their team in this area. The technique has been applied to more than 10 different kinds of machines including: turning centers and machining centers; small, medium and large machines; new products and retrofitted machines. The accuracy improvement is in the range of 3-10 times. The error sources being compensated for include machine geometric and thermal errors, cutting force-induced errors, and workpiece thermal errors. The paper discusses some important aspects of the technique: the general approach for developing real-time error compensation system; the formulation of the error synthesis model; the mapping of the machine errors; optimal modeling; thermal error mode analysis; the optimization of the sensor locations; cutting force-induced error compensation; compensation control implementation; and other critical problems in the real-time error compensation technique. (C) 1998 Elsevier Science Ltd. All rights reserved.