A behavioral layer architecture to integrate telecollaborative virtual manufacturing operations

A behavioral layer architecture is used to augment a network virtual reality environment to perform collaborative virtual manufacturing operations. The core of the layer consists of a virtual manufacturing lattice (VML) structure, an object library and a virtual manufacturing script (VMS), combining to form a collaborative virtual manufacturing environment (CVME).; The VML is a multiple hierarchy structure representing the 3D objects as nodes and their properties are encapsulated in a 4-tuple structure. The 4-tuple describes the 3D object composition, precedence relationship with other objects, event control list and interface to external modules to perform specialized tasks, such as collision detection and motion planning. The object library is used to index the 3D object primitives, which are used in the lattice. It is useful in reducing the lattice structure to a simple hierarchy making it easier to implement and maintain.; The VMS, similar to the numerical control (NC) programming concept, is a high level scripting mechanism used to simulate virtual manufacturing operations. It consists of a set of generic overloaded operators to perform specialized functions.; The availability of adequate network bandwidth is a key factor while performing collaborative virtual manufacturing tasks. Network latency and jitter are the common problems encountered in the event of a network saturation. A series of network experiments were conducted to determine the average network latency using three different network protocols: TCP, UDP and Ping; three sampling rates: 15 frames per seconds (fps), 30 fps and 60 fps; three different packet sizes: 27 bytes, 55 bytes and 110 bytes of data over two different network medium: Ethernet and ISDN. The observations provide the basis for optimizing the data to be transferred over the network to reduce latency and jitter and local usage of the VMS to maintain continuity in the CVME.; The CVME provides a medium to perform human-machine interaction and to link with other application mediums, such as filtering 3D objects from 2D photographs, MPEG-4 video stream and cut and paste operations from the virtual environment. These are useful mechanisms for integrating the CVME with existing applications.