In the context of using virtual environments (VEs) in Internet-based teleoperation, this paper addresses the issue of parameter acquisition for single-image-based modeling of VEs. By studying the properties of basic three-dimensional features such as point sets and edge corners, a parameter-searching method was developed that employs virtual objects as feature-matching templates. This approach is particularly valuable if the environment is subject to unpredictable change.

For pt.I. see ibid., p.383-8. This paper addresses the issue of path planning in a virtual environment (VE) for the control of an Internet-based robot manipulator. A hybrid method is proposed in which the dimension of the path-planning problem is reduced by separating the problem of planning the position of the gripper from that of planning the pose of the gripper. A global configuration-space technique is used for the former and a local operational-space technique is used for the latter. Particular attention is paid to fundamental issues such as mapping the graphical model into configuration space, on-line collision detection and obstacle avoidance in the VE.

Virtual environment (VE) techniques provide a powerful tool for the visualisation of the 3D environment of a teleoperation work site, particularly when "live" video display is inadequate for the task's operation or when its transmission is constrained, for example by limited bandwidth. However, the ability of a VE to cope with the dynamic phenomena of typical teleoperation work sites is severely limited by its pre-defined model-based nature. Thus, an online composing mechanism is needed to make it environment-compliant. This paper describes a method for this purpose, based on workspace analysis, in which objects are constructed from simple 2D images and VEs are modelled interactively. Experiments have shown that the method is convenient and effective for online VE editing.

A system for WWW-based remote robot tele-operation is presented. It addresses important problems of Internet telerobotics such as "how do we make the system reliable?", "how do we make the system fast?", and finally, "how do we make the system open and portable?". The recent open technologies Java and Java3D are used for developing the system. Key features of the system are: (1) the Java3D based "live" virtual representation of the real robot and its environment, and (2) the use of a powerful tool for the remote programming of the robot. Possible applications of the teleoperation tools developed and methods within VR are also briefly discussed.