位置检测单元是中、高档CNC机床闭环数字伺服系统的重要组成部分。其作用是检测位移并以数字量的形式送入控制计算机构成闭环数字控制。实践表明:一个设计完善的闭环数字伺服系统,其定位精度与加工精度主要由位置检测单元所决定。位置检测单元一般由测量元件加位置检测接口组成。若为模拟式测量元件,由其输出信号的幅值或相位来得到位移计数值就形成两种不同的检测系统,即幅值检测系统与相位检测系统。当前在各类CNC 机床上,由旋转变压器(以下简称“旋变”)构成的幅值检测系统和相位检测系统均获得广泛 Position detection unit is medium and high-end CNC machine tool closed-loop digital servo system is an important part. Its role is to detect displacement and digital form into the control computer to form closed-loop digital control. Practice shows that: a well-designed closed-loop digital servo system, its positioning accuracy and processing accuracy is mainly determined by the position detection unit. Position detection unit generally by the measuring element plus position detection interface. If the analog measuring element, the amplitude or phase of the output signal to get the displacement count value to form two different detection systems, namely amplitude detection system and phase detection system. Currently in all types of CNC machine tools, by the resolver (hereinafter referred to as “spin”) consisting of amplitude detection system and phase detection system are widely