SU484466A1 - Device for measuring linear accelerations - Google Patents

Description

one

The invention relates to the field of motion measurement.

The known devices for measuring linear accelerations, containing a base with reinforced rod resonators, an inertial element, electromechanical excitation circuits of the resonators, made in the form of exciters and oscillation receivers electrically connected to each other through amplifiers, and a filter mixer, are inoperable under vibration effects a certain frequency and amplitude acting along the axis of sensitivity of the device.

In order to ensure operability under vibration effects, the proposed device is equipped with frequency dividers connected between the outputs of the amplifiers and the inputs of the mixer.

FIG. 1 is a block diagram of the described device; in fig. 2 illustrates the dependence of the Bessel coefficients for the fundamental frequency and the first two side components of the FM oscillations on the modulation index and graphs illustrating the nature of the change in the spectrum of signals for different modulation indices. In the drawings, the following symbols are used:

/ o (-) - Bessel function of the first kind

2

a zero order defining the amplitude of the fundamental harmonic of the FM oscillation;

BUT/

- j-Bessel functions of the first kind of the first and second order, respectively, defining the amplitudes of the 1st and 2nd lateral components of the FM-oscillation;

D f - the maximum deviation of the frequency of the resonator when exposed to vibration overload;

Af is the frequency of vibrations (modulating frequency);

D /

-module index.

D /

The device consists (Fig. 1) of base 1, in which rod resonators 2 and 3, inertial element 4, electromechanical excitation circuits of resonators made in the form of causative agents 5, 6 and oscillation receivers 7, 8 electrically interconnected through amplifiers 9 are strengthened. , 10, frequency dividers I, 12, and a mixer 13 with a filter.

The device operates as follows: the inertial force acting through the element 4 increases the natural frequency, for example, of the stretching resonator 2 and

reduces the natural frequency of the compressing resonator 3. From the output of amplifiers 9 and 10, signals with frequencies fi and fz are fed to frequency dividers 11 and 12 with a scaling factor equal to, for example, the difference between the output of the mixer 13,

proportional to the effective linear overload.

When exposed to vibration along the axis of sensitivity with a frequency less than the natural frequency, the oscillations of the resonators 2, 3 are modulated by the vibration frequency and the output

amplifiers 9. and 10 (modulus index -

the signals become frequency-modulated, which causes the output of the mixer 13 in addition to the pitch of the difference frequency of the spectrum of the side components of the difference signal, the amplitude of which in this case is significant (Fig. 2). At the same time, the output difference signal loses the signs of FM oscillations and undergoes significant amplitude distortions. The division of the frequency before the supply to the mixer, carried out by dividers 11 and 12, reduces the modulation index to –1, this leads to a significant narrowing of the width of the spectrum of FM oscillations and a decrease in the side components, which makes it possible to isolate the output signal of the mixer 13 without noticeable distortion of its form and thus ensures the operability of the device under vibration effects.

Subject invention

A device for measuring linear accelerations, containing a base with reinforced sterile neval resonators, an inertial element, electromechanical "excitation circuits of resonators, made in the form of pathogens and oscillation receivers electrically connected to each other through amplifiers, and a mixer with a filter, characterized in that In order to ensure the operability of the device under vibration effects, it is equipped with frequency dividers, including between the outputs of the amplifiers and the inputs of the mixer.

five

Fi & 1