This diploma thesis implements methods for a measurement of rotational speed. It is implemented on the Compact RIO platform from National Instruments. Corresponding SW is implemented using the graphical programming language G in LabView environment. Developed system uses two different sensors – incremental encoder and tacho sensor for measurements of rotational speed. Thesis further analysis and implements a method for an encoder nonlinearity determination and for its on-line correction. For used methods, effects adding errors into the measurements are evaluated and quantified.

The aim of the thesis is to study the problems of induction motors, which belong among the most widespread and used machines. Due to their expansion, it is advisable to start the fault monitoring to prevent any more damage and losses. It can be used for condition monitoring different types of methods, which are variety technically and costly demanding to implement. It is used the method of measurement using stator currents in this thesis, because these currents are already monitored and it is easy to create devices for a more detailed analysis. The whole monitoring is carried out using products from National Instruments. The program of monitoring is created in graphical setting of LabVIEW. The analysis is conducted by calculating the Fast Fourier transform of the time signal. The result is the frequency spectrum, which contains frequency peaks and some of these peaks represent failure. The test data are collected with a DAQ device and then the same data are used for creating a methodology for evaluating online analysis and it is subsequently implemented into CompactRIO.