基于系统辨识的宽频大尺寸振动台正弦扫频控制

Sine wave sweep control for wideband jumbo-size vibration system based on system identification

宽频大尺寸振动台在其频率范围内具有复杂的动态特性,一般的控制方法很难实现高精度的扫频控制。提出了基于系统辨识的正弦扫频控制方法,首先对振动台进行了系统辨识分析,求出了振动台在指定频率范围内的幅频响应函数,据此得出了系统在每个频率点的输入,然后进行了正弦扫频,按照一定的规律改变频率,保持振幅不变;扫频过程中结合分段PID算法,对控制中出现的误差进行了实时修正,从而保证了正弦扫频的精度。最后给出了运用该方法对宽频大尺寸振动台进行控制的实验结果。结果表明,这种控制方法可以实现宽频大尺寸振动台高精度的扫频控制。

The control system of the vibration system should realize precision control on complex dynamic situation, especially for wideband jumbo-size vibration system. The sine wave sweep control based on system identification was introduced. It could simply be described as analyzing the system identification, resolving the response in the appointed waveband and gain the input in each test point first, then the sweep control kept the magnitude fixed and changed the frequency according to regular pattern. PID arithmetic was adopted to increase the level of accuracy and anti-disturbance. At last the data gained in the experiment was presented. According to the result, the control method could properly be used for the wideband jumbo-size vibration system.