The Design And Implementation Of Real-Time Ethernet Image Transmission System Based On RTAI/RTnet

Nowadays, image transmission system has become an indispensable part in people's daily life with the rapid development of computer network and communication technology.The technology using real-time operating systems and real-time network protocols in network transmission is received more and more attention and application research to meet the demands of the growing amount of network transmission information and speed.At present,it is still at the starting stage in our country.Ethernet is got widely applied for its low-cost and high reliability.The mechanism that Ethernet used to resolve concurrent medium access confines its application in time-critical fields.With the growing requisitions of all kinds of high real-time application,many corporation and standard organizations put forward technological solutions to increase Ethernet real-time characteristic, which include many kinds of real-time Ethernet varieties.RTnet is one of them.It is an open source real-time network stack and provides deterministic networking based on Ethernet hardware and real-time operating system RTAI. Compared with classic network transmission,RTnet permits better time-critical, deterministic networking.In this paper,real-time image transmission system based on RTAI/RTnet is studied and realized.Firstly, the basic ideas and realization mechanism of RTAI are analyzed,and RTAI system based on Linux is implemented.The LXRT module is introduced in details.The method creating a real-time task in user space is also presented.Secondly,the RTDM and its application RTnet are discussed and RTnet based on RTAI is also implemented.Then video capturing and compression,image transmission and displaying are realized. The real-time image transmission system in client-server model based on RTAI and RTnet is implemented through repeated tests. In the paper,the security about RTAI and RTnet is further studied. With RT-DTE the security access control model in Real-time, the three major aspects confidentiality, integrity, and availability of RTnet are analyzed simply.In the eighth chapter,the test of image transmission system in the experimental environment are given,and the test results in experimental and Linux environments are compared.Finally,the works done in the thesis are summarized,while the deficiencies and improvements are also given.