Research On Virtual Teaching Experimental System Of Computer Control Foundation

The course of "Computer Control System", a required course for Mechnical&Electrical professionals, is about linear and quasi-linear discrete system. The prime problems to be solved during the research on the physical model of this system are its mathematical narrative, model building and analytical tools.In practice, it is observed that students find it hard to master the mathematical model of computer control theory, namely, the pulse transfer function. Hence it is essential to visualize the abstract theories through experiments, and thus deepen student’s understanding of computer control system. However, Building the corresponding platform of these experiments requires some specific instruments, which greatly increases the cost of instruction.Thanks to the development of science and technology, a virtual instrument technology that combines the technologies of computer science, digital signal processing, software engineering and standard bus, has provided a new solution. We could take advantage of the powerful computer and image precessing capabilites of computers, and use them to build up a virtual experiment system of computer control theory for instructional use. The virtual experimental system of computer control system has the virtual instrument programming software Lab VIEW2010as its development environment with the combined usage of control design and simulation toolkit and PID and Fuzzy Logic toolkit, and uses this software’s advantage on graphical programming to complete the virtual experiment development of the system.The virtual experimental system covers the fundamental concepts and theorems mentioned in"Computer Control System", including experiments on various subjects, such as Nyquist-Shannon sampling theorem, discretization of linear continuous system,the relationship between pulse transfer function and the system stability,steady state and dynamics state characteristic of the system,introduction of controller general design methods and how to use PID controller, dead-beat controller to improve system performance. At last,it uses the experiment on shearer drum rounded-up control system, computer control modification of lathe servo feed system and double-capacity tank liquid level control system as an example, and demonstrates the application of computer control theory.In the overall process of designing the system, because this virtual experiment system cover many sub-experiment. In order to avoid the confilict between each module, the main program adopt the structure of the producer/consumer, and uses sub-panel and dynamic calling of sub-VI technology, this solves the load and display ploblems of front panel on the main interface.Besides, this system employs window color selection and layout optimization, which ameliorate the interface.This virtual experimental system requires low configuration, and it is to easy operate. Moreover,it is fully compatible with the course covered by "Computer Control System". Its output results and curves are all based on input parameters, and it has remarkable advantages on visibility, interaction and scientific reliability.The system has already been applied into instructions, and has received satisfying feedback. Therefore, it is practically meaningful to design and develop a virtual experiment system of "Computer Control System" for the undergraduates. This is the direction of future development to the universities’laboratory.