Internet random time delay constitutes a major challenge for Internet-based teleoperation systems. Since the uncertain time delay may degrade the system performance, and even lead to instability. Although large-scale research works have been conducted on the understanding, testing, and analysis of Internet round trip time delay (RTT), it is not appropriate to use RTT in control methods design. It is well known that control commands arrive at the slave site in an aperiodic manner as a result of Internet random time delay. The subsequent control command will terminate the execution of the current command. Consequently, we will get precise information for slave system once the time delay jitter can be known in advance. This paper proposes a novel research idea for Internet-based teleoperation system from the point of view of delay jitter prediction. Statistical properties of the time delay jitter are investigated. Furthermore, the sparse multivariate linear regression method is used to give prediction on Internet time delay jitter. Simulation results demonstrate that sparse multivariate linear regressive method gives a precise prediction, which indicates that the proposed control method based on Internet time delay jitter has a broad prospect in teleoperation systems.

Prior researches of generalized predictive control (GPC) in teleoperation systems have mainly considered short transmitted time delays or single degree of freedom (DOF) manipulators of master and slave. This paper presents a GPC strategy for space teleoperation systems in which the master and slave manipulators are both multi-DOF and the communication network brings long time-varying delays. The nonlinear dynamics of the multi-DOF slave manipulator is linearized and described by a linear state-space equation. Meanwhile, a nonlinear compensator is used to compensate the nonlinear parts of the slave. Then, based on the equation, a state-space model based GPC controller is designed on the master side to stabilize the system and make the slave manipulator track the master position and velocity no matter whether the manipulator contacts with the environment or not. Finally, a simulation example is given to illustrate the effectiveness of the proposed method.

Robotic teleoperation constitutes a key technique for networked manufacturing system. Since Internet is noisy and performance of telerobotic systems strongly depends on communication conditions, control strategies which could be used to distribute computation and communication resource properly and require less data transmission are required. Motion description language (MDL) is an appropriate solution. In this paper, comparison study between MDL-based and the traditional direct control method under randomly varying time-delay condition has been pursued which show that the MDL-based method has the ability to guarantee the stability of the whole telerobotic system under randomly varying time-delay condition. Furthermore, MDL-based method provides an uniform mathematical description on discrete control on the master site and continuous execution on the slave site. Simulation results indicate that the proposed method is promising for Networked Manufacturing development.

A MDL-based control method for tele-robotic systems over internet is presented in this paper. Internet-based tele-robotic systems are characterized by the fact that the operator and the remote robotic system are connected by Internet. Since limited bandwidth, random time delay and other transmission problems deteriorate performance of tele-robotic systems severely, control strategies which can be used to settle transmission problems are expected. The obvious characteristic of the new method introduced in this paper is that control commands have a linguistic flavor, data transferred between operator and remote robot can be reduced accordingly. The framework presented in this paper has the potential of reducing operator's working pressure and enhancing the performance of the system. Furthermore, the existing motion description language modal is expanded to deal with the packet loss and disorder problem. The main contribution of this paper is the development of a novel framework for tele-robotics and its implementation in a real tele-manipulator system.