Czasopismo
Tytuł artykułu
Autorzy
Wybrane pełne teksty z tego czasopisma
Warianty tytułu
Measurement of electric error of a resolver in digital angle measurement system
Języki publikacji
Abstrakty
Przedstawiono zautomatyzowane stanowisko do badania układu cyfrowego pomiaru kąta z transformatorem położenia kątowego (tpk) w roli przetwornika pierwotnego. Pomiar błędu elektrycznego opracowanych modeli wielobiegunowych tpk przeprowadzono na tym stanowisku metodą bezpośredniego porównania kątów oraz z wykorzystaniem wzorcowego źródła sygnałów. Omówiono również metody pomiaru błędu elektrycznego tpk wykorzystujące zasadę zerowania napięć. Przedstawiono przykładowe wyniki badań.
In digital angle measurement system (Fig. 1) accuracy can be increased by applying multi-pole resolvers and precise R/D converters. During tests of such system it is important to determine not only overall accuracy, but also error components introduced by resolver and R/D converter. It is especially important for systems reaching 1 minute of arc accuracy, when resolver and electronic converter must be perfectly matched. Laboratory stand designed for complete testing of digital angle measurement devices is presented on Fig. 2. One of the methods of measurement of electric error of a resolver is based on direct comparison of angles alpha(a) derived from resolver output voltages) and alpha(c) (at the output of R/D converter) with reference angle alpha (measured by high-precision sensor). Assuming, that the overall error is the sum of resolver error delta(tpk) and converter error deltaR/D, those errors can be calculated according to (1). Analysis of resolver error delta(tpk) leads to a conclusion that, for errors around minutes of arc, it is difficult to distinguish resolver and converter-related error components, whereas the overall error can be easily determined. The tests were carried out for two-speed pancake resolvers having different speed ratios and the same universal magnetic circuit. The schematic diagram of resolver's windings is presented on Fig. 3. Resolver has its rotor excited with sinusoidal voltage 10V/4500 Hz. Alternative method of determining electric error of a resolver is based on balanced impedance (or resistance) bridge [2, 3]. Resistance ratio of two opposite arms of the bridge is related to the output voltage ratio Us/Uc according to (2) and (3). Electric circuit utilising null voltage technique is presented on Fig. 4. Impedance ratio is set according to tab. 1 and the resolver is rotated until zero voltage is obtained on phase-sensitive voltmeter. The angle between position set on a bridge and null voltage position is an electric error of a resolver. Another method of determining electric error uses reference signal source. In this method resolver signal simulator SIM-36010 was used [4]. Its block diagram is presented on Fig. 5. The simulator has 16-bit resolution and š25 sec of arc accuracy (unloaded). The idea of error measurement is shown on Fig. 6. Simulator excites the stator with voltages according to given angle and the electric error is determined by measurement of rotor voltage. Electric error was measured using direct angle comparison and with resolver signal simulator. The results are shown on Fig. 7 and 8. The results are very similar which proves the uselfulness of direct angle comparison method in determining the electric error of various types of resolvers. Repeatability of measurement results speaks well for mechanical stability of a test stand. It should be mentioned, that the method using resolver signal simulator can be easily automated and applied in the production process, giving significant cost and time savings.
Słowa kluczowe
Czasopismo
Rocznik
Tom
Strony
155-165
Opis fizyczny
Bibliogr. 4 poz., tab., rys.
Twórcy
Bibliografia
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.baztech-article-BPS2-0014-0050