Research On Multichannel Signal Acquisition System Onboard

This subject is derived from the multi-channel signal test requirements of a certain type of UAV,which consist record various working parameters during the flight of the UAV,and read and analyze the test data after the flight,thus providing a reliable basis for new machine development,accident and troubleshooting.Based on the research status at home and abroad and the relevant technical indicators and the practical application environment,this paper designs an airborne multi-channel signal acquisition system.The system uses a modular and top-down design thought to make the overall plan,the work is mainly carried out from two aspects: Hardware Circuit and Control Logic.The hardware circuit part is composed of four parts: Analog Quantity Acquisition,Digital Quantity Transceiver,Core Control and Power Management.The sampling of 16 channels of analog signals is realized by multi-channel analog switch and single-chip A/D converter;The transmission and reception of the 8 digital signals are completed by a isolated RS422 conversion chip;The Spartan-6 series FPGA is used as the core control chip,and the NAND Flash is used as the memory,and the data transmission between the host computer is realized by the Gigabit Ethernet;All parts of the system are powered by a high-efficiency and low-power management module.The Control Logic mainly includes analog acquisition,digital transceiver,memory invalid block management,ECC checksum,and read,write,erase operation control and MAC layer drive control of Gigabit Ethernet communication interface.The multi-channel signal acquisition system designed has been tested and verified in the laboratory environment.The test results show that: the system works normally,and channel switch and A/D sampling timing are matched in the analog acquisition process,and the sampling accuracy is higher than 0.3%;The data transmission and reception of each digital channel is accurate,and there is no frame loss;The high-speed and high-reliability data transmission is realized through the Gigabit Ethernet interface and the host computer,and the transmission speed can reach 900 Mbps or more without error.The phenomenon meets the requirements of design indicators and has good use and promotion value.