SU1525586A1 - Electrostatic accelerometer - Google Patents

Abstract

The invention relates to a measurement technique and can be widely used for measuring the parameters of movement of objects. The aim of the invention is to improve the accuracy of the accelerometer due to the linearization of the displacement sensor and the elimination of its moments of gravity. The goal is achieved by including hyperbolic linearization circuits on operational amplifiers 8 and 9 in the feedback circuit of the compensation circuit by connecting the outputs of amplifiers 8 and 9 through phase-sensitive demodulators, differential amplifier 12 and adders 13 and 14 with power inputs of hyperbolic circuits and using a pulse source 16 nutrition The compensation force is created by the difference in voltage across the electrodes 4, 6 and 5, 7, which linearizes the characteristic of the electrostatic compensator. 1 il.

Description

The invention relates to the measurement and measurement of technical technology and can be widely used for accurate measurements of linear accelerations, accelerations of the scientific research institute of gravity and parameters of the spin of objects.

The purpose of the invention is to improve the accuracy of the accelerometer by linearizing the characteristics and eliminating the moments of the capacitive displacement sensor of the accelerometer.

The drawing shows a schematic diagram of an accelerometer.

The accelerometer contains a movable sensitive element 1, for example, from a crinkle, on an elastic suspension 2 and a housing 3. On the sensitive element 1 there are two isolated electrodes 4 and 5. On both sides of the sensitive element there are two fixed plates with electrodes 6 and 7 isolated on them they are connected to the input of operational amplifiers 8 and 9, and electrodes 4 and 5 are connected to the outputs of amplifiers, which are connected to the inputs of phase-sensitive demodulators 10 and 11, connected to the input of differential amplifier 12, whose outputs are from a unified Nena to inputs of adders 13 and 14 and are supplied to inputs of a differential device 15. To the second inputs of adders filed synchronized pulse from the modulator 17, reference voltage source 16 by Up.

The phase-sensitive demodulators 10 and 11 are controlled from the modulator 17. The outputs of the adders 13 and 14 through the reference capacitors C are connected to the inputs of the operational amplifiers 8 and 9. The pairs of electrodes 4, 6 and 5, 7 form elements of a capacitive position sensor combined with an electrostatic compensator .

The device works as follows.

In the presence of acceleration, the inertial force acts on the sensitive element 1, which in the compensation circuit is balanced by the force of the electrostatic compensator.

The movement of the sensitive element under the influence of inertial force causes a change in the capacitances between the electrodes 4, 6 and 5, 7.

Changes in capacitances are transformed by hyperbolic chains of capacitive displacement sensors on output voltages.

5 0 5 o

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The output of operational amplifiers 8 and 9, which are detected by phase-sensitive demodulators 10 and 11. The difference in output voltages of the frost-sensitive demodulators is amplified by differential voltage: 12 with differential output. The output impulse voltages of amplifier 12 are summed with the impulse reference voltage of source 16 and converted by a hyperbolic circuit into compensating voltages that are applied to electrodes 4, 6 and 5, T.,

The compensation force is created by the difference in voltage across the electrodes, which linearizes the characteristic of the electrostatic compensator.

The measured acceleration is proportional to the amplitude of the pulse voltage of the differential device 15.

Thus, the use of a hyperbolic circuit at the same time as a displacement transducer and in a feedback circuit to linearize the characteristics of the electrostatic compensator allows linearizing the accelerometer displacement sensor and eliminating its drag points.

Claims (1)

Invention Formula Electrostatic accelerometer, comprising a case- sensitive element in the form of a plate made of single-crystal material placed on an elastic suspension; isolated electrodes located on the sensitive element and the case; reference capacitors, phase-sensitive demodulator, differential and operational terminals, modulator and source reference voltage, characterized in that, in order to increase the accuracy of the accelerometer, two adders and a subtracter are introduced into it, the second operating amplifier and A phase-sensitive demodulator, a differential amplifier are made with a differential output, the reference voltage source is pulsed, the first plates of the reference capacitors and electrodes on the case are connected to the inputs of operational amplifiers, the outputs of which are connected to the corresponding electrodes on the sensing element and through Phase-sensitive 51525586 and demodulators - differential inputs connected to the modulator, amplifier, the outputs of which are co-which in turn is connected to  with subtractive device and second phase-sensitive inputs first inputs of adders, second demodulators, and outputs of adders the inputs of which are connected to the output are connected to the corresponding second source of pulsed reference on-plates of reference capacitors.