Design And Implementation Of High-Precision Signal Acquisition Equipment For Power Equipment Structure

In the acceptance stage of aircraft power equipment,in order to monitor and analyze the stability of the power equipment structure,it is necessary to conduct precise tests on the changes of parameters such as gravity,pressure and vibration of its structure.The acquisition accuracy of traditional acquisition equipment is relatively low and cannot meet the signal acquisition requirements in specific application scenarios.Therefore,this paper designs a high-precision signal acquisition device based on the characteristics of parameter changes of power equipment structures in terms of equipment power supply,signal acquisition and data transmission.In the power supply part of the device,a monitorable power supply output card is designed to realize the output of low ripple voltage signal and real-time monitoring,which provides a guarantee for the high-precision acquisition of sensor signals.In the signal acquisition part,the signal conditioning circuit and sampling quantization circuit are optimized by analyzing the change characteristics of the measured sensor signal and the channel sampling mode,i.e.,the high-frequency signal and low-frequency signal are conditioned with low noise,a high-order FIR filter is added to the logic control of FPGA to weaken the switching noise and highfrequency interference introduced during signal conditioning and filtering,and oversampling technology and depolarization filtering are adopted to reduce the signal quantization noise and pulse noise generated during acquisition.Algorithms are used to reduce the quantization noise and pulse interference generated during signal acquisition,thus reducing the impact of noise on acquisition accuracy and realizing high-precision sampling of signals.In the data transmission part,data transmission and command interaction between the internal boards of the device are realized through a custom backplane bus;the acquisition device and the host computer use the Ethernet TCP protocol for data communication,and display,analyze and process data in real time at the host computer.By building a test platform to test and analyze the power output,signal acquisition and data transmission functions of the device.The results show that the output power ripple of the power supply board is stable within 0.2m V,the channel acquisition accuracy of the acquisition board is better than 0.05%,and the isolation degree between channels is less than-80 d B.After several experiments,the data transmission process has achieved high reliability of data transmission with continuous frame count and no frame loss.