Reliability Analysis And Optimization Design Of Virtual Instrument Based On Soft Measurement Technology

Virtual instrument, which combines the advantages of traditional instrument and computer technology, gradually replaces the traditional measurement equipment because of its powerful features and cost-effective value. With extensive application of virtual instrument, the reliability of virtual instrument has received growing attention. Obviously, there is considerable specificity between the reliability of virtual instrument and traditional instrument, since the virtual instrument is a combination of hardware and software. So, to improve the reliability of virtual instrument, not only we need to ensure the reliability of its hardware, but also carry out more considerations of its software. In this paper, the current transformer test system is taken as a study case to detailed describe the reliability analysis technology of virtual instrument, and propose a variety of method to improve system reliability. Meanwhile, reliability model of current transformer test system was given out.The main contributions of this paper are as follows:1. Recalled the development history of virtual instruments and soft measurement technology, summarized the theories and implementation method of these two technologies.2. Using the technology of virtual instruments and soft measurements to give out the implementation solution of current transformer test system. The test system has full advantage of computer hardware and software, which could achieve automation of data collection, data analysis and data processing. The test system breaks through the traditional instruments in the measurement of speed and functions, and provides an advanced mean to inspect quality of current transformers.3. Proposed analytical method of reliability of virtual instrument, and applied the analytical method to current transformer test system. Reliability modeling, prediction and allocation provide mathematical basis for the reliability analysis, while failure mode effects analysis (FMEA) and fault tree analysis (FAT) have important significance for the improvement of virtual instrument and prevention of faults.4. In accordance with the virtual instrument reliability modeling technology, hardware/software reliability model of current transformer test system were given, which provide the mathematic method for reliability prediction, allocation, and reliability design of the product.5. Proposed an adaptive correction measure of zero errors, using the radial basis function (RBF) neural network based on coordinate particle swarm optimization (CPSO). The application of technology in the current transformer test system shows that hat this measure is of great help to constrain the zero error and increase precision of instruments.