The Research On Video Processing And Remote Control Of Unmanned Aerial Vehicles Based On IOS Mobile Terminal

In recent years, Unmanned aerial vehicle was not only used in the military field, but also widely used in civil field. At present, the control of unmanned aerial vehicle is mainly based on manual control. With the popularity of mobile devices, the method of mobile terminal instead of traditional control handle has become more advanced solutions to small unmanned aerial vehicle.This article firstly carries out requirement analysis about video process and flight remote control, determines video processing performance involving resolution, delayed and caton,and makes an agreement on flight instruction transmission protocol and finishs the overall design of the system. The unmanned aerial vehicle system is divided into two parts of front-end and back-end mobile terminal. The flight front-end adopts the V4L2 interface to collect the raw video data, uses Interframe motion estimation method to encode original video data as h.264 format video data, sends encoded video data to the mobile control back-end according to the Real Time Streaming Protocol. Mobile terminal back-end receives the h.264 format the video data, obtains the YUV format video frame data by decoding these h.264 format video data using Entropy decoding algorithm, and then uses Image rendering technology of the iOS to real-time render the video data in the screen of mobile terminal.Meamwhile, video capture and record is realized in mobile terminal back-end.In terms of flight control, mobile terminal back-end makes authentication applications to flight front-end, and gets access codes by decrypting these return data which were encrypted with advanced encryption standard algorithm. Then, mobile terminal back-end gets the flight control instructions through the virtual joystick and accelerometer interface and sends these instructions and access codes to the front-end. Flight front-end control the flight of unmanned aerial vehicle after authentication passes.The function of system was tested in the laboratory and actual flight environment for a month. The test results showed that the average delay of video processing was 353 ms,average broken was 0.43 times and average mosaic was 0.008 times, and the flight of unmanned aerial vehicle can be control using mobile terminals virtual joystick and accelerometer, and the average delay was not higher than 152 ms.