DEVELOPMENT OF A COLLABORATIVE CAD CAM SYSTEM

This paper presents the development of a collaborative CAD/CAM system (COCADCAM). COCADCAM extends an existing single-location CAD/CAM syste m to a multi-location CAD/CAM application so that two geographically d ispersed CAD/CAM users can work together on a three-dimensional CAD-ge ometry coediting and CAD-related tasks collaboratively and dynamically . COCADCAM dynamically supports CAD data communication that are not av ailable in traditional single-location CAD/CAM. The dynamic data commu nication is achieved through the development of networking algorithms and CAD/CAM functions in this paper. The networking algorithms based o n UNIX Interprocess Communication (IPC), the Network File System (NFS) , and a connection-oriented client and server model under the Transmis sion Control Protocol/Internet Protocol (TCP/IP) suite. The CAD/CAM fu nctions included surface modelling, simulation of a milling toolpath, and post-processing of an NC program following collaborative CAD-geome try coediting, which are directly or indirectly supported by the Appli cation Programming Interface (API) of the CAD/CAM software. The networ king algorithms and CAD/CAM functions together can facilitate an envir onment for CAD-geometry coediting and related tasks such as design, an alysis and manufacture. COCADCAM has been successfully implemented thr ough local area network (LAN) and the Internet; a remote machining cel l is also linked so that the generated NC program based on a coedited free-form surface can be used for the physical machining operation. Th e algorithm proposed by COCADCAM can be referenced for the extension o f other single-location CAD/CAM systems to multi-location applications . (C) 1998 Elsevier Science Ltd. All rights reserved.