Design Of Model Free Flight Measurement And Control System Based On FPGA

In the modern aerospace vehicle development process,flight testing is required,and the traditional collectors are difficult to cooperate with the wind tunnel free-flight experiments due to the volume layout and transmission control,and the traditional cable transmission signal is also easily affected by the experimental environment.In this study,we designed a model free-flight measurement and control system that integrates multi-type data acquisition and wireless communication.The system is a trinity of data acquisition on the airborne side,signal control on the ground side,and real-time analysis on the upper computer side.The system adopts dual module mode for wireless communication and transmission to achieve full-duplex wireless communication;four 8-channel synchronous sampling ADCs for analog signal acquisition of PWM servos and wind sensors;17 UART serial ports for digital signal transmission of servos,IMU sensors and attitude sensors;FPGA is responsible for timing drive and logic control of the system,and real-time data interaction between all ends.The specific work of the full paper is as follows:1)The electronic interface standards of each type of sensor carried by the free-flying model are analyzed,and for each type of sensor,UART interfaces with different protocols are designed to receive sensor data;the interaction methods of each platform of the measurement and control system are analyzed,and the system communication link of dual-band wireless communication plus Ethernet communication with A7196+ESP32+W5500 is proposed;and the control characteristics of FPGA programming devices are studied to establish the overall design of the FPGA-based model free-flying measurement and control system.The board of the airborne side is restricted by the use of scenarios,and is designed in two boards,the top and bottom,and the boards are connected by FPC soft line to reduce the area of the board.2)Complete the software control logic design of the measurement and control system based on the business logic of the model free flight test.We design each hardware circuit according to the logic control module to realize the circuit function;according to the interaction logic between different platforms,we adapt the data frame of communication,which is convenient for each platform to parse and split the data;in order to synchronize the interaction data of each module in the system,we design the FIFO cache queue to ensure no data loss and save the controller resources;According to the business logic of model free flight test,we optimize the sensor data reception logic;According to the business logic of model free flight test,the sensor data reception logic and the rudder control logic are optimized to reduce the time delay of test completion,and the interaction logic of different platforms is optimized to prevent the conflict of business between platforms.After the experimental test,the measurement and control system can manipulate the flight model to complete the flight action,and can parse the received data,the delay from the upper computer to the parsed data is about 5ms,and the system transmission rate can reach4 Mbps.The whole system has the characteristics of stable transmission,flexible configuration and low latency,and has achieved the expected goal.