Internet Based Time Delay Model Research In Robot Teleoperation System

Internet technology brings a brighter future of extensive application for network-based tele-robotic systems.But the Internet time-delay and other transmission problems deteriorate the performance of tele-robotic systems. So, it has great significance to model time delay of Internet for teleoperation system based on Internet.Traditional model method, such as normal distribution, can not describe the time delay distribution of Internet. The normal distribution is a symmetrical distribution structure, but actually the time delay distribution is a dissymmetrical and excursion distribution structure.A suitable time delay model should have curve excursion, and there is a shifted gamma distribution close in upon time delay probability density distribution of Internet.According to these principles, we propose a time delay model method of Internet based on shifted gamma distribution, which fully considers the dissymmetrical characteristics of time delay, and lays the foundation for the tele-robotic system design. Then we establish the program framework of testing time delay, draw the chart of testing program, and implement recording and program of Internet communication. We propose and implement the program of testing time delay, and design four different location experiment to testing time delay based on TCP protocol and UDP protocol, and record the whole corresponding data. The results of experiments proved the validity of time delay model.Based on least two power method, we estimate the three parameters of time delay model of Internet based on shifted gamma distribution. Through the contrast between estimate curve and time delay probability density distribution, we proved the validity of time delay model method based on shifted gamma distribution.Time delay model method based on shifted gamma distribution overcomes shortcomings of traditional methods, which implement dissymmetrical structure of time delay distribution, and depict time delay distribution characteristic of Internet accurately. It has great significance to improve the performance of the tele-robotic systems.