叶尖定时传感器的定时精度直接关系到旋转叶片振动的测量精度。针对电容式传感器的定时精度问题,建立了双极性脉冲信号的数学模型及处理电路的控制论模型,分析了信号频谱及系统的冲击响应,选择合适的带宽并设计了电路系统,利用计算机对信号与冲击响应的卷积进行仿真得到足够小的信号过零点的延时。由此,设计了一套实验系统并给出了实验中测得的输出波形。
The measurement accuracy of rotating blade vibration is directly related with the tip-timing precision of the blade tip-timing sensor that is discussed. Mathematical model of bipolar pulse signal and cybernetics model are setup, and the signal's spectrum and impulse response of the circuit system are analyzed. Accordingly, appropriate bandwidth is chosen to design the circuit system. Then, by using computer to convolute the signal and impulse response, short enough zero-crossing time delay of the signal is obtained. Thereout, experimental system is designed and the output waveform tested during experiment is shown.