Personal Computers in Laboratory Teaching of Control

This paper reports on the incorporation of personal computers in the laboratory program at UMIST's Control Systems Centre. Laboratory practice is an integral component of all our control course. The laboratory facilities provide a mechanism for testing and verifying theoretical and design approaches. Incorporating computers in all phases of the laboratory program makes possible the use of current techniques in the analysis and design of realistic control systems. The control systems laboratory at UMIST has been developed with the goal of providing real world analysis and design experience in a laboratory setting. A collection of scale model experiments representing the major categories of industrial control problems has been constructed. These working models are coupled with a standard instrumentation interface and analogue and digital computers to implement control strategies. In all cases, great care has been taken to retain realism and allow the student to concentrate on control issues rather than configuration or programming problems. The primary objective of using personal computers in the control laboratory is to provide an on-line link between the student and the laboratory model. This provides direct ‘hands on’ experience of digital control ideas, interactive digital control experimentation and use of the computer as a multi-function virtual instrument. In addition, the computer is used off-line to simulate model performance as various control strategies are tried. At this point in time, each laboratory model station has been equipped with a personal computer containing A/D and D/A converters, hard and floppy disk, and a real-time clock. The computers are networked to provide access to printing and file storage facilities. Originally the software packages were written primarily in BASIC, and ran on BBC computers. These versions are however in the process of being replaced by PC-based packages written in C. Both the original BASIC and the C-successors have been developed to provide interactive, real-time control of the model using a choice of digital control algorithms. Using the keyboard as a control panel, the student can observe model performance, vary controller parameters, choose display characteristics and record parametric and graphical data. Future developments will expand the choice of available control algorithms and enhance the off-line analysis and design tools.