REAL-TIME DATA ACQUISITION SYSTEM WITH ON-LINE VISION

Abstract

Digital imaging techniques have contributed to many advancements in the field of automation. This project designs, develops and tests a real-time data acquisition system which combines on-line vision with real-time data acquisition. The system design is based on object-oriented principles. This is an "agent" based design, where the main feature is the encapsulation of all activities associated with a parameter being monitored into one entity by tying them together, beyond the boundaries of hardware and across the network.

The system software consists of two major components; an interactive graphics editor, real-time plan (RT-Plan) and a run-time module, real-time view (RT-View). The integrated editor RT-Plan allows the user to define a background process picture, which is a camera image. Dynamic components, which have a set of pre-defined presentation schemes are interactively positioned on the visual scene. Dynamic components can be associated with analog or discrete parameters. For analog parameters, the digital read-out displays are the representation schemes. For discrete parameters, a dynamic component can be associated with each discrete state of the parameter. This will allow potential animation features on top of the real-time vision scene.

The system is designed for Windows platforms. The prototype system, which has been successfully developed and tested, comprises of a programmable logic controller (PLC) system connected to a personal computer (PC) through the serial communication link and a video camera connected to the same PC by means of a video capture board. The hardware and software components connected to the PLC system are referred to as the real-time data server and the part to which the camera and the capture board have been connected is referred to as the real-time vision server.

The software allows real-time data acquired through the PLC system to be displayed on the visual scene providing a user friendly factory data monitoring system. The software has been developed using C++ programming language and tested on Pentium personal computers.

An advanced design for extension of the combined view over a high speed ATM network has been included in this project. Such an extension will facilitate the remote monitoring of factory operations on a real-time basis.