一、前言由于数控(NC)机床和工业机器人的性能的不断提高和价格的不断下降,依赖于过去的通用机床与专用机床的机械工厂,正在以迅猛的势头向着提高生产率和无人化进军。它们正在尽一切力量为了谋求飞速的提高生产率,从控制单台机床和生产线的一部 I. INTRODUCTION Due to the continuous improvement of the performance of CNC machine tools and industrial robots as well as the continuous price declines, the machinery factories relying on the past general-purpose and special-purpose machine tools are moving rapidly toward increasing productivity and unmanned business. They are doing everything in their power to speed up productivity, from controlling a single machine and a production line