Design And Implementation Of Aircraft Power Ground Detection System Based On FPGA

In the aviation industry,the power supply system provides the necessary electric energy for the flight of the aircraft.The quality of the aircraft power supply has a great impact on the reliability and safety of the aircraft,so the requirements for its performance indicators must be quite strict.At the beginning of the design of the power supply system,it must be tested in strict accordance with the aircraft power supply standards.The steady-state parameters affecting the performance and quality of aircraft power supply detected by existing equipment are not comprehensive,the equipment is large in size and complex in operation,and the relative error and sampling rate only meet the basic conditions required by the standard.Therefore,how to make the test equipment more portable,higher sampling rate,further reduce the relative error is the urgent need of aircraft power ground detection equipment.Therefore,based on the national and international standards related to the performance and quality parameters of aircraft power supply,and relying on the airborne electronic equipment tester R&D project of Kairui Measurement and Control Technology Co.,LTD.,this paper designs the ground detection system of aircraft power supply that uses the combination of portable industrial computer and FPGA.The portable industrial computer is used as the hardware platform of the system.FPGA is used to realize the sequential logic control of the voltage data acquisition circuit and store the data.PCI9054 bridge chip is used to realize the high-speed data transmission between the data acquisition module and the computer bus.The system mainly collects the voltage signals of the constant frequency AC power supply system and the low voltage DC system in the aircraft power supply,supports the online live detection of the signals,carries on the electrostatic protection in the test environment,and designs the analog input protection circuit,which can realize the analysis of the steady-state parameters of the aircraft power supply.On the basis of summarizing the relevant research at home and abroad,this paper designs the ground detection system of aircraft power supply.In terms of hardware,the industrial computer is used as the hardware platform of system detection.In view of the electrical parameter requirements of the aircraft power supply to be measured,the main tasks are as follows:(1)In terms of hardware design,a multi-channel data acquisition module based on FPGA is designed,which has 32 channels parallel data acquisition function to achieve the acquisition of AC voltage and DC voltage;The second-order active low-pass filter is used to remove the interference of high frequency signal.ADS8568 chip is used to realize parallel acquisition.SDRAM data storage device is used to realize the function of multi-channel data cache.DMA data transmission is realized by PCI9054 bridge chip.(2)In the aspect of software design,using the modular design method,choose ISE software combined with Verilog language to realize the design of FPGA logic program.The ADC control module program,gain control module program,acquisition channel control module program,FIR digital filter module program,FIFO control module program,SDRAM controller module program,CPCI bus controller module program,etc.(3)Write the top-level application program with Labview,realize the operation system’s control of the multi-channel data acquisition module by calling the API function provided by PLX Company,and design the data acquisition interface and data analysis interface.The system test results show that the ground detection system of aircraft power supply meets the hardware requirements of users.The number of test equipment channels is not less than 16,the number of ADC bits is not less than 12,and the sampling frequency of AC/DC steady-state parameters is not less than 72 k Hz.In the hardware circuit design of the system,the second-order active low-pass filter is used to effectively filter the high-frequency noise interference.In software design,the least square method is used to carry out multi-point curve fitting to the measurement data,and the measurement error can reach the high precision requirement of ±0.01%.The measurement errors meet the standard requirements of steadystate characteristic parameters of AC(AC voltage,steady-state AC voltage,voltage imbalance,voltage modulation amplitude,voltage phase difference,AC distortion coefficient,peak coefficient,DC component of AC voltage,steady-state frequency)and steady-state characteristic parameters of DC(steady-state DC voltage,DC distortion coefficient,DC voltage fluctuation amplitude).According to the design scheme proposed in this paper,the product design is completed,the finished product is delivered,and the ground detection of the aircraft power supply is realized,which meets the market demand and has certain practical application value.