电视导引头伺服系统传动齿隙是产生图像抖动的重要因素,为了分析齿隙大小与图像抖动幅度的关系,文中在某型电视导引头伺服系统模型基础上,采用描述函数法建立传动齿隙的非线性模型,根据推广的奈奎斯特稳定性判据分析缝隙大小对系统稳定性的影响,并用图解法推导计算系统自振频率和幅度,最后推导出齿隙大小与电视导引头图像抖动幅度关系,并通过Simulink建模仿真验证了计算方法有效性。

Transmission backlash of TV-seeker servo system was an import influence factor for image vibration. In order to analyze the relationship between transmission backlash width and image vibration amplitde, this paper used describing function method to construct nonlinear model of transmission backlash. According to Nyquist stability criterion, the effect of gapsize on the stability of the system was analyzed. And the natural frequency and amplitude of the system were deduced by graphic method. Finally we got the relationship between the TV-seeker's image vibration magnitude and the backlash size. Using Simulink we constructed a whole servo system model to test the effectiveness of the new analysis method.