对复合材料结构的冲击事件进行机载在线监测具有迫切的应用需求。面向机载研制了一种基于两级判别逻辑的小型化冲击区域监测系统。首先,提出了一种基于两级判别逻辑的冲击区域定位算法,能够在大规模可编程逻辑门阵列(FPGA)中实现基于冲击数字序列的冲击事件在线记录,并提高了冲击区域定位的准确性。其次,研制了小型化冲击区域监测系统,采用无源滤波器和比较器,将压电传感器输出的冲击响应信号直接转换为冲击数字序列,采用FPGA替代数字电路并实现冲击监测,简化了常规冲击监测系统的电路,降低了系统的尺寸和功耗。系统具有体积小、重量轻、功耗低以及支持传感器数目多的特点。验证结果表明:该系统能够正确响应每次冲击事件并能准确定位冲击发生的区域。
It is highly necessary to monitor impact events occurring on composite structures on line and on board.In this paper,an airborne oriented miniaturized impact region monitoring system is developed based on a two-step decision logic.First,the two-step decision logic based impact region localization method is proposed,which is realized in a field programmable gate array(FPGA)and used to record impact events online.The accuracy of impact region localization is improved by using this method.Second,a miniaturized impact region monitoring system is developed.In this system,passive filters and comparators are used to replace the analog circuit and turn the impact response signals directly into digital sequences,and an FPGA is used to replace the digital circuit,which simplifies the circuit and greatly reduces the size and weight of the impact monitoring system.The system has the following characteristics:small size,light weight,low power consumption and numerous piezoelectric transducers supported.The experimental validation results obtained on a carbon fiber composite wing box structure with many stiffeners and bolts show that the impact region monitoring system can respond to impact events and localize them accurately.