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Wang Shilong
Jian Yi
Liu Fei
Institute of Mechanical Engineering,
Chongqing University,
Chongqing 400044, China
Robert Young
Department of
Manufacturing Engineering,
Loughborough University,
Loughborough LE11 3TU, UK |
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NOVEL STRUCTURE FOR DISTRIBU- TED
NUMERICAL CONTROL*
Abstract:
Because of an unexpected signal noise within the network or an unpredicted fault with personal computers (PCs), many problems emerge in the implementation of distributed numerical control (DNC) with PCs-based network. To solve the problems, an industrial solution of involving the field-bus technology in DNC communicating area is provided. A kind of advanced Field-bus, named controller area network (CAN), is originally developed to support cheap and rather simple automotive applications. However, because of its good performance and low cost, it is also being considered in automated manufacturing and process control environments to interconnect intelligent devices, such as modern sensors and actuators. Recently it creates a new role for CANBus in DNC that brings new thinking to DNC. CAN is used as the network platform for connecting machine tools to share information with each other reliably. Additionally, thanks to also applying of “plug-in” technology and a special interface of hardware, this solution exhibits some high compatibility with different pedigree numerical control (NC) systems, such as Fanuc, Siemens, Cincinnati and so on. In order to improve CANBus for DNC application, a communicating competition model of the basic CAN protocol, called CC model, is then highlighted. This model is able to satisfy the requirements that different machine tools share the communicating bandwidth fairly when they run concurrently. Finally the novel view of the latest advancement in CANBus-based DNC in combination with the manufacturing paradigm is also presented.
Key words: Distributed numerical control CANBus Fieldbus CAM
Manufacturing automation |