Design Of Aviation Cable Fault Detector Based On Tdrand TDC

Aviation cable is the nervous system of an aircraft. It can transmit power, controlsignals and data for the electrical, avionics, communications and control systems of anaircraft. Accurately detecting aviation cable faults is very important for the aircraft flightsafety in aircraft maintenance. The aviation cable fault detector based on TDR and TDCcan detect the open circuit and short circuit fault and locate the fault place on the aviationcable.Firstly, this paper constructs a circuit model to study the electrical characteristics ofaviation cable and studies on the basic principle of detecting and locating cable fault byTime Domain Reflection. Secondly, this paper analyses the common technology of timeinterval measurement and improves the structure and measurement principle of traditionaltapped delay line method to make it meet the requirement of the time intervalmeasurement system in the aviation cable fault detection. Thirdly, each functional moduleof the aviation cable fault detector based on TDR and TDC is designed in detail. Thefunctional modules include pulse amplifying circuit and reflected pulse acquisition circuitof the signal processing circuit, and the modules which generated in FPGA, such astransmitted pulse producing, TDC time interval measurement system, measurement datacache and core processor. Finally, the feasibility of aviation cable fault detecting by timedomain reflection method is verified through experiment and the performance of aviationcable fault detector is tested.Experimental results show that the aviation cable fault detect based on TDR and TDCcan accurately identify open circuit and short circuit fault of the aviation cable. The errorof the aviation cable fault location is less than1cm. The performance of aviation cablefault detector meets the requirements for aircraft cable fault detection in aircraftmaintenance.