Doświadczalne wyznaczanie wybranych parametrów akcelerometrów MEMS - wyniki prac badawczych

W artykule przedstawiono problem doświadczalnego wyznaczania najważniejszych parametrów metrologicznych akcelerometrów MEMS. Szczegółowo omówiono zagadnienie justowania akcelerometrów względem stanowiska badawczego. Wskazano na niewyjustowanie akcelerometru jako najistotniejsze źródło błędów wskazań tych przyrządów. Podano wartości niektórych parametrów metrologicznych dla przykładowych akcelerometrów. Odniesiono się do podobnych prac prowadzonych przez różne ośrodki badawcze na świecie.

paper addresses the issue of determining metrological parameters of MEMS accelerometers in an experimental way. Methodology of performing such studies as well as the related test rig are presented by the author in [1]. Short discussion on similar works carried out by others, reported e.g. in [2-4], [8-10], [14-15], is included. Much attention is paid to the problem of aligning the accelerometer in the test rig. The obtained results proved that misalignment is a factor affecting the sensor accuracy most significantly. That can be clearly observed by comparing the courses in Figs. 2 and 3, where the misalignment almost directly increased the error of sensor indications. Such errors as cross-axis (or transverse) sensitivity, perpendicularity of the sensitive axes and hysteresis are briefly addressed in Sections 4-6. Yet even though magnitudes of these errors are not significant in the case of dual-axis accelerometers that have been tested, it may turn out that it is not so in the case of triaxial accelerometers . It is shown that owing to compensation of systematic errors (such as the cross-axis sensitivity or misalignment) or even elimination of various kinds of errors (e.g. misalignment, errors resulting from the accepted way of calibration) an improvement in sensor performance may be achieved. At the end, some parameters as estimators of the accuracy of MEMS accelerometers are proposed.