中文摘要：

伺服系统的频率特性能直观反映伺服系统的精度、平稳性和响应速度。通过测量伺服系统的频率特性对伺服参数进行调整，使其满足加工的动态特性要求，具有重要意义。以频率分段变化的正弦波作为被测伺服系统的激励信号，结合傅里叶变换，提出一种伺服系统频率特性测试方法——分段正弦单步法。并基于HNC-8型数控系统，利用该方法开发了伺服频率测试软件。实验结果表明，该方法能有效测量伺服系统频率特性。

英文摘要：

The frequency characteristic of servo system can directly reflect the performance of the servo system in aspects of accuracy, smooth and response etc. It＇s very important for servo system turning. After researching method of frequency characteristic test of servo system, a method called segment sine wave single-step method was developed based on HNC-8 system. In this method, a sine wave whose frequency changes segment by segment was used as the driving signal, and Fourier transform was used as the major data processing method. Experiments and applications indicate that the method is hiahly efficient and precise.