Virtual Instrumentation for Control Applications

The virtual instrumentation (VI) is rapidly replacing classical analog as well as digital instrumentation systems owing to the availability of high performance microprocessors based PCs, fast Analog-to-Digital Converters (ADCs) and sophisticated data communication technology. Therefore, investigation of more and more efficient and effective VI based solutions to modern instrumentation problems is one of the main research areas for design engineers. The work presented in this paper is application oriented and thus the contribution of the paper is how to instigate the already known control algorithms in NI LabVIEW. Instead of relying on commercially available expensive hardware, a low-cost self-developed DAQ card is employed. The elaboration of the idea is carried out by designing a VI based DC drive and a thermal system. Modeling, PID controller and user-interface development is presented for both examples. The positive results of this study establish the utility of virtual instrumentation especially for control applications.