Design And Implementation Of Multimode Uav Remote Control System

Safe flight is the premise of unmanned aerial vehicle(UAV)flight,the stable transmission of control signals and safe operation of operators play a crucial role.This paper designs and implements the multimode remote control system of UAV based on Long Range(LoRa),and combines the frequency hopping technology to fully demonstrate the characteristics of LoRa in anti-interference and anti-Doppler effect.In order to make up for LoRa’s disadvantage in data transmission rate,adaptive modulation and coding(AMC)technology is adopted to maximize data transmission rate while ensuring robust communication.In addition,the ranging function of the system not only provides judgment basis for AMC technology,but also allows users to obtain accurate real-time flight distance between ground station and UAV,which is conducive to improving users’ safety control awareness.The data transmission and distance measurement functions of the system run at the same time during normal operation.When the data transmission fails due to fault,the distance measurement function will timely change the working mode to save,providing effective guarantee for safe flight.The main work of the dissertation is as follows:(1)According to the application scene of UAV remote control system,the overall scheme of UAV multi-mode remote control system is designed.Based on the characteristics of UAV communication channel,LoRa technology and frequency hopping technology are used to resist multipath effect and doppler effect.According to the demand of high rate data transmission,adaptive modulation coding technique is adopted to maximize the data transmission rate when the frame error rate is satisfied.(2)The hardware platform of UAV remote control system is designed and realized,including microprocessor,memory,RF transceiver,RF front end and power supply.On the hardware platform,the hardware driver layer and the hardware abstraction layer are built.The hardware driver layer realizes the operation mode setting,wireless transmission configuration,communication status acquisition and interrupt response of the RF transceiver.As the bottom layer of the software architecture,the hardware abstraction layer hides the hardware details of the microprocessor and RF transceiver from the upper layer,making the upper layer software independent of the hardware platform.(3)According to the functional requirements of the system,the application software of the UAV multi-mode remote control system is designed and realized,including communication protocol,adaptive modulation and coding,frequency hopping communication,real-time distance measurement and double-node coordination.The application software is deployed to the ground side and the UAV side.(4)In this paper,the multimode remote control system of UAV is tested for functions and performance.The test results show that the functions of the system meet expectations and the performance meets the design requirements.