| With the rapid development of aerospace technology,aerospace experiments put forward more and more diversified functional requirements for data measurement systems.In the flight test preparation state,because the data measurement system aircraft is completely separated from the ground communication interface,it is unable to complete the issuance of the start recording command,and the data measurement system needs to complete the real-time storage of the data collected during the test by receiving the command,so as to realize the subsequent data download and analysis.To solve the above problems,a data measurement system is designed to realize data acquisition,transmission and power control.Firstly,the technical indicators of the data measurement system are analyzed.Combined with the research status at home and abroad,a data measurement system composed of data acquisition and editing recorder,power manager and ground measurement and control platform is designed.Secondly,the key technologies of each part of the data measurement system are studied and designed: Based on the working principle of temperature sensor,heat flow sensor and flow rate sensor,the filter circuit and compensation circuit are designed to make the acquisition accuracy of each channel meet the requirements of technical indicators,and the storage of acquisition data is controlled by FPGA;A power control circuit composed of linear optocoupler,charge management chip and low-power STM32 chip is designed to realize the switching from ground power supply of the data measurement system to the power supply on the aircraft and the delay start function.The logic design of single-chip microcomputer is carried out to control the delay error within 3S;According to the requirements of accurate instruction distribution and fast data return,the RS-422 interface circuit and communication protocol are discussed in detail,and the LVDS transceiver circuit and data transmission logic are designed.Through the configuration and logic design of fmql chip,the data communication between Gigabit Ethernet PL and PS is realized.Finally,a test platform is built to comprehensively test the acquisition accuracy,functional integrity and data transmission of the data measurement system.Many tests have proved that the data measurement system has an accuracy of 0.4% for the temperature,flow rate and heat flow compensation resistance,2% for the heat flow small voltage signal,and 32.25mb/s for the return rate of stored data.It meets the design functional requirements and various performance indicators,and the working state is stable. |
