Analysis And Design Of Dc Motor Control System Based On The Virtual Instruments In NI

Experiment teaching plays an important role in college engineering education. However, the rigid teaching mode and the backward experimental equipment have restricted the improvement of teaching quality for a long time. Along with the development of microcomputer and software, the virtual instrument technology"The software is the instrument"has developed quickly. The virtual instruments has obvious technical advantage in intelligent,processing power,performance ratio and maneuverability aspects compared to the traditional instruments. Introducing virtual instrument into experiment teaching can not only improve test efficiency and teaching quality, but also provide an effective way and method to reduce the cost for experiment instrument. The aim of this paper is to change the traditional experimental teaching mode. Based on the virtual instrument in NI, we developed an experimental projects of PID control system of DC motor for the <<Automatic Control Principle>> curriculum, and accumulated beneficial experience for the future of virtual experiment teaching reform,the construction virtual laboratory and the development of the experimental teaching system of virtual instrument.Firstly, this paper elaborates the domestic and foreign relevant subject status and development trend in this subject research, makes clear the importance of this research and the main research task. Then , we introduce the research hardware and software conditions: NI ELVISⅡ+ teaching laboratories virtual instrument package,QNET-DCMCT DC motor training board and the virtual instrument software development environment LabVIEW.NI ELVISⅡ+ teaching experimental platform provides students with a hands-on platform to learn the complete industrial processes such as the theory,design,prototype and realization. Combined with third board,teachers can teach circuit,control,survey and instrument,communication,embedded or micro controller,aviation dynamic,electromechanical sensors,optical fiber transmission theory and many different professional courses.We introduced the theory of PID control technology, deeply discussed the motion characteristics,parameters measurement,model of open loop closed-loop,design and realization process of PID controller of DC motor. Completed the LabVIEW design of the PID control system of the dc motor speed and position based on QNET-DCMCT interface card and analysis the effect of the adjustment of PID parameters on system control.And,by building hardware circuit on the NI ELVISⅡ+ prototype experiment board, we designed a dc motor speed measurement and speed for the PID control system. This is a beneficial exploration and try of introducing virtual instrument to the experimental teaching of the course <<Automatic Control Principle>>.Finally, the paper summarizes the research work and presents some future work about the research.