RU2526508C1 - Method to assess dynamic characteristics of angular speed sensors - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: method is based on using a double centrifuge with independent drives of two platforms - a rotor and a rotary table installed on it. The investigated angular speed sensor is installed onto the rotary table so that the axis of rotation of the small table matches the axis of sensitivity of the angular speed sensor. When rotor rotation speed is set to provide for impact of static acceleration and speed of rotary table rotation, varying in accordance with the harmonic law, in the direction opposite to the direction of the centrifuge rotor, onto the investigated sensor of angular speeds a modulated signal of angular speed of the specified frequency will arrive. Determination of amplitude-frequency and phase-frequency characteristics of the sensor is carried out by means of serial variation of frequency of the set harmonic angular speed, and also comparison of signals at the inlet and outlet of the investigated sensor.

EFFECT: possibility to assess dynamic characteristics of angular speed sensors under impact of static acceleration at them.

Description

The invention relates to the field of measurement technology and can be used to determine the dynamic characteristics of angular velocity sensors under the influence of static acceleration on them by measuring their frequency characteristics.

A known method for determining the frequency characteristics of accelerometers using a double centrifuge with independent drives of two platforms, which is a rotor with a rotary table mounted on it. The sensor under study is placed at a fixed distance r from the axis of rotation of the rotary table, while the double centrifuge reproduces simultaneously constant and harmonic linear accelerations proportional to the speed of rotation of the centrifuge, the amplitude of which depends on the distance from the center of rotation to the sensor transducer. The elimination of errors caused by the sensitivity of some types of accelerometers to angular velocity is achieved by setting the rotation speed of the turntable equal to the rotation speed of the main axis of the centrifuge in the opposite direction [Sinelnikov A..E. Low-frequency linear accelerometers. Methods and means of verification and calibration. - M .: Publishing house of standards, 1979, p.87-89].

This method is selected for the prototype of the invention.

The specified method allows the determination of the frequency characteristics of accelerometers, but is not applicable for angular velocity sensors, since a harmonic change in linear acceleration, rather than angular velocity, is provided.

The objective of the invention is to improve the method for assessing the dynamic characteristics of angular velocity sensors, in particular, when exposed to static accelerations of more than lg by measuring their frequency characteristics (amplitude-frequency and phase-frequency).

The problem is solved in that the angular velocity sensor is installed on the rotary table of a double centrifuge in such a way that the axis of rotation of the small table coincides with the sensitivity axis of the sensor under study. The static acceleration acting on the device under study will be

, где Ω_ротора - угловая скорость вращения ротора центрифуги, R - расстояние между осями вращения ротора и поворотного стола. Погрешности воспроизведения ускорения, вызванные неточностью установки датчика на оси стола, можно считать несущественными. При этом скорость вращения поворотного стола задается равной скорости вращения основной оси центрифуги в обратном направлении.

where Ω of the _rotor is the angular velocity of the rotor of the centrifuge, R is the distance between the axes of rotation of the rotor and the turntable. Acceleration reproduction errors caused by inaccurate sensor installation on the table axis can be considered insignificant. The rotational speed of the turntable is set equal to the speed of rotation of the main axis of the centrifuge in the opposite direction.

To ensure the possibility of determining the frequency characteristics of the angular velocity sensors, the rotary table, in addition to constant rotation, implements harmonic oscillations of the angular velocity. As a result, the rotational speed of the rotary table changes according to the harmonic law Ω of the _table = sin (ωt) -Ω of the _rotor . In this case, the modulated signal of the angular velocity of a given frequency Ω = sin (ωt), where ω is the frequency of harmonic oscillations of the angular velocity, will be input to the sensor under study

, где A_вых(ω) - амплитуда сигнала на выходе датчика, A_вх(ω) - амплитуда сигнала на входе датчика. Получение фазочастотной характеристики производится путем сравнения фазы сигнала на входе и на выходе датчика угловой скорости на различных частотах задаваемых гармонических колебаний: $$\psi \left(\omega \right)=\frac{{\psi }_{вых}\left(\omega \right)}{{\psi }_{вх}\left(\omega \right)}$$

, где Ψ_вых(ω) - фаза сигнала на выходе датчика, Ψ_вх(ω) - фаза сигнала на входе датчика.The frequency characteristics of the studied sensor are determined by successively changing the frequency ω of the given harmonic oscillations of the angular velocity of the turntable. The amplitude-frequency characteristic is obtained by comparing the amplitudes of the signal at the input and output of the angular velocity sensor at various frequencies of the given harmonic oscillations: $$A\left(\omega \right)=\frac{A_{\mathrm{at}sx}\left(\omega \right)}{A_{\mathrm{at}x}\left(\omega \right)}$$

where A _o (ω) is the amplitude of the signal at the output of the sensor, A _in (ω) is the amplitude of the signal at the input of the sensor. Obtaining the phase-frequency characteristic is performed by comparing the phase of the signal at the input and output of the angular velocity sensor at various frequencies of the specified harmonic oscillations: $$\psi \left(\omega \right)=\frac{{\psi }_{\mathrm{at}sx}\left(\omega \right)}{{\psi }_{\mathrm{at}x}\left(\omega \right)}$$

where Ψ _o (ω) is the phase of the signal at the sensor output, Ψ _in (ω) is the phase of the signal at the sensor input.

As a result, it becomes possible to determine the dynamic characteristics of the angular velocity sensors under the influence of static linear accelerations of more than lg on them by measuring their frequency characteristics.

Claims (1)

A method for assessing the dynamic characteristics of angular velocity sensors when subjected to static accelerations by measuring their frequency characteristics, namely, that the angular velocity sensor under study is placed on a rotary table of a double centrifuge, while the angular velocity of the rotary table is set equal to the speed of rotation of the main axis of the centrifuge in in the opposite direction, characterized in that the rotary table along with constant rotation implements harmonic oscillations, while changing the frequency of the harmonic ble oscillation angular velocity of the turntable and comparing signals at the input and the output of the angular velocity sensor.