Distributed Processing Using Single-chip Microcomputers

摘要

This project investigates the use of single-chip microprocessors as nodes in a token ring control network and explores the implementation of a protocol to manage communication across such a network. A control network is useful when the event to be controlled is located at some distance from the inputs required to control it; likewise, a control network is useful when an application receives inputs from more sources than a single microprocessor is capable of handling. Such a network allows nodes to share only the information that is essential for each to perform, eliminating the need for a powerful and costly computer. This makes it extremely effective in a wide variety of applications ranging from missiles to home security systems to smart automobiles. One type of control network is the token ring network, where each node is connected serially with the node immediately following tt and the one preceding it. Its efficiency, simplicity, and determinacy make it an excellent choice in a small control network. A specific scenario is examined where the position of a marble along a motor driven track is controlled using inputs from a user operating a PC as well as a microcomputer-driven interface module, an optical encoder mounted on the motor, and a camera located above the track. Using the information of the state variables as well as preferences of the user, a digital control system is developed to move the marble to the proper position.