Study on design of visual intelligent detection instrument for aviation cable fault

Aviation cable is used to transmit electric energy and signal, and its performance directly affects the safety of aircraft. It is difficult to locate cable faults on aircraft and there is a lack of suitable high-precision detection equipment. Based on the Time-Domain Reflectometry Technology (TDR), combining with the embedded systems such as Raspberry Pi and FPGA, an aviation cable fault detector is designed. Firstly, based on the frequency-doubling clock generated by the PLL, the detector emits a low-voltage pulse whose width is smaller than the cycle of the source clock. Then, based on the multiple ADC sampling method, the detector samples the reflected pulse. Finally, the detector uses the intelligent algorithm to automatically determine the fault type and fault location, and displays the sampling waveform and detection results on the LCD screen. Through experimental verification, the detector can basically meet the requirements of aviation cable fault detection. 航空电缆用于传输电能和信号，其性能直接影响飞机的运行安全。针对飞机上电缆故障难以定位，并且缺少合适的高精度检测设备的问题，基于时域反射技术（TDR），结合树莓派、FPGA等嵌入式系统，设计了一种航空电缆故障检测仪。检测仪通过PLL倍频时钟发射宽度小于时钟源周期的低压脉冲，基于多重ADC采样法对反射脉冲进行采样，应用智能化分析算法自动判断故障类型和故障位置，并在液晶显示屏上直观显示采样波形和检测结果。经过实验验证，该检测仪基本能够满足航空电缆的故障检测需求。