The Design Of The UAV Data Link

As the electronic technology, communication technology and automatic control technology and the increasing maturity of the application scope of small unmanned aircraft is becoming more and more widely, especially in the field of civil got rapid development. Data link system as an important part of uav system, is mainly responsible for data transmission between plane and ground station, under the premise that guarantee the reliability of the transmission, how to ask communication protocol interoperability has become the key issues in the data link system design. This subject is to build a set of low cost, high efficiency, strong commonality, flexible and reliable small uav data link system, provide reference for standardization of uav data link in the field of civil.At first, this paper deeply studied the uav data link system function structure, and puts forward a based on wireless digital radio Si4432 single link space data transmission system design; And technical performance of the system of the key module, the hardware design and the interface problem has made an analysis, identify the basic architecture of data link system.Next is the overall design of the uav data link system, then designs and realizes a small unmanned aerial vehicle(uav) communication protocol, the content of the agreement of the flight control data in detail, and gives more machine communication protocol, the protocol implementation in the field of information and node extensibility. According to the agreement completed each node in different development environment data message packaging, analytical general software development. For general serial port and so realize the data message in each node to send and receive processing, introduces in detail the design and implementation of a flight control data link, the main contents include point-to-point link communication protocol, and to ensure the antilock congestion control.In the wireless communication environment, inevitably there will be a similar foreign same frequency or frequency interference, wireless communication system in this paper, do work in the 433 MHZ band, when the same frequency or frequency interference similar to the band, lead to errors of each node to receive data. In order to solve this problem, in a point to multi-point wireless communication system, joined the frequency hopping mechanism, carrier frequency by changing the si4432, replace a new channel. Workflow master node will check before sending data channel, if the check to the channel is interference, the random retreat for a period of time, to check the channel, within the prescribed number of times, the channel has been busy, the master node randomly change the channel.In improving the stability of the data link at the same time, also make the link transmission speed is improved, and completed the course study, the requirements of the relevant finally is to design test for instance data link system, further verify the reliability and practicability of the system.In this paper,the independent design of small uav data link system compared with the conventional solution, greatly reduces the communication cost and complexity of the system, adopts single link wireless transmission method, in the case of a guaranteed transmission rate, and the data transmission efficiency, etc have greater improvement at the same time, the standardization of link protocol also provides a specification to the further development of the project work.