Motion control for linear motor feed drives in advanced machine tools

Minimum-time path optimization (MTPO) and minimum-time tracking control (MT TC) have previously been introduced as effective strategies for controlling high-speed machine tools [D. Renton, M.A. Elbestawi, High speed seruo cont rol of multi-axis machine tools, Int. J. Machine Tools Manuf. 40 (2000) 539 -559]. It has been argued that the effectiveness of these strategies is due to their ability to accommodate the dominating saturation effects in contr ol of high-speed machine tools. In this paper the application of MTPO and M TTC to linear-motor-driven machines is examined. It is found that the atten tion paid to saturation limits by MTPO and MTTC strategies provides signifi cant performance improvements for linear-motor-driven machines. Issues such as improved stiffness to periodic disturbances, improving holding torque t hrough heat-reducing commutation methods and improved sensor feedback are a lso examined. (C) 2001 Elsevier Science Ltd. All rights reserved.