Research On UAV Intelligent Control System Based On Cloud Platform

With the rapid development of unmanned aerial vehicle(UAV)technology,its application has been extended from the initial military field to the field of civilian consumption,and the corresponding ground control station(GCS)technology is becoming more and more mature.Ground station is the abbreviation of ground control station,which includes software and hardware.It is the core of UAV control system and has the functions of track planning and real-time monitoring of UAV flight status.Different types of UAV and different scenarios will put forward different requirements on the performance of ground station,especially the computing power.At present,large ground station systems are mostly deployed on special computers,which have poor portability and high system maintenance cost.When the computing power can not meet the application requirements,it can only be solved by simply increasing the hardware cost.In addition,the common ground station equipment can only control one UAV at the same time,which is not convenient for the cooperative operation of multiple UAVs.With the development of cloud computing and internet technology,many applications with higher requirements on computing power have migrated to cloud platform,which not only effectively reduces the hardware cost of the system,but also meets the dynamic requirements of computing power in different task scenarios.In view of the above situation,this paper proposes an intelligent control system of UAV based on cloud platform,and puts forward the corresponding scheme in image transmission and flight control respectively.The main work of this paper includes the following aspects:(1)The video coding standard of H.264 is studied systematically.The functions of video coding layer and network abstract layer in H.264 standard are analyzed.The coding flow and code stream structure generated after coding are understood.The key techniques such as intra-frame and inter-frame prediction,integer transformation and quantization are analyzed.(2)The real-time messaging protocol(RTMP)is studied.The handshake flow between client and server and messages' structure are analyzed in detail when communicate with RTMP,and the blocking rules of RTMP messages are understood.(3)A scheme of UAV image transmission based on cloud platform is proposed.The UAV is connected to Internet through a WiFi or 4g module,video is encoded on the UAV,and the generated code stream is packaged and published to a streaming media server on a cloud platform in real time.Based on the development board of Qualcomm snapdragon flight,combined with the libopenh264 and librtmp open source library,the video coding and stream pushing module is designed and developed,and the scheme is verified.(4)A flight control scheme of UAV based on cloud platform is proposed.The traditional ground station software is migrated to the cloud platform to provide a web server-based user interface for operation and control of UAV flight.The flight principle and MAVLink communication protocol are analyzed for common quadrotor.Combined with the open source flight control software PX4 and the robot operating system ROS,the UAV application program is developed,which can control the UAV through the cloud platform.In conclusion,this paper designed UAV image transmission and flight control scheme based on cloud platform,and verified the feasibility of the scheme through experiments.