SU474739A1 - Accelerometer - Google Patents

Description

The invention relates to a measurement technique and can be applied in the measurement of accelerations.

The known accelerometers containing an acceleration sensor with a frequency output, mounted on the rotor, and a counting recorder, are not sufficiently accurate due to the frequency of the signal at zero acceleration.

The proposed accelerometer is equipped with two rotor position sensors installed at diametrically opposite points, a trigger, the inputs of which are connected to the outputs of position sensors, and two electronic keys, the control inputs of which are connected to the trigger outputs, and switching circuits to the inputs of the counting recorder and the sensor output accelerations.

This makes it possible to increase the accuracy of the measurement of the acceleration by eliminating the effect of sensor frequency drift.

The drawing shows the scheme of the proposed accelerometer.

The accelerometer consists of an acceleration sensor - a sensing element J located on the rotor of the sensor, an electronic switch 2 electrically through a current collector connected to the sensitive element, sensors 3 of the rotor position and a recording device 4.

The acceleration sensor - the sensitive element consists, for example, of a quartz piezoelectric vibrator, loaded with an inerion mass and included in the electronic circuit of the generator. The switch contains electronic switches 5 controlled by trigger 6, the state of which is set by the signals of the position sensors 5. The recording device contains a reversible counter 7 and an indicator 8.

The device works as follows.

Under the action of acceleration, the inertial mass deforms the quartz vibrator Il1 another acceleration sensor with a frequency output. The frequency of the mechanical vibrations of the vibrator, and hence the electrical oscillations of the generator, varies in proportion to the magnitude of the deformation. During rotation, the vibrator is alternately subjected to compression and tension deformations; at this time, the frequency of the generator accordingly increases and decreases from nominal.

Two position sensors 3 are located at diametrically opposite points of the stator and the signals from them arrive at trigger 6 through a half turn of the rotor. The trigger-controlled keys 5 pass the signal of the sensing element to the summing input of the reversible counter 7 for one half of the rotor's turn and to the subtracting input for the second half of the turn.

3

With a uniform rotation, the number of pulses n accumulated on the counter per revolution will be:

g

“- (A, -2 +) i. d / l -

/ D / y

 A. u sinu) / dt, J g,

where / "- the nominal frequency of the vibrator; L ;; - the period of rotation of the sensor; co is the angular velocity of rotation; V - sensitivity sensitivity

element to accelerate; q is the acceleration value. The moments L / 2 and 3 correspond to the beginning, the middle and the end of the turn and coincide with the sigpals of the sensors. Since / 2-1

D 9, then II sin (ot df

Zj

-.

t:

For any period of time T, integer number of turns, the number on the reading device of the sensor

, 2vT N d.

to

ch

From where: -j „The given expressions show that in the driven device of the results the frequency of the quartz vibrator f ,, and, therefore, its slowness is changed (significantly lower rotation speeds) is excluded.

The accelerometer can measure two components of acceleration located in

plane perpendicular to the axis of rotation. To do this, it may contain two additional diametrically positioned position sensors that are shifted relative to the first by an angle, for example, a rabbi 90 °. An additional electronic switch connected to the additional position sensors separates the second acceleration component perpendicular to the first one.

Subject invention

An accelerometer containing an acceleration sensor with a frequency output mounted on the rotor, and a counting recorder, characterized in that, in order to increase accuracy, it is equipped with two sensors and rotor sensors installed at diametrically opposite points, with a trigger whose inputs

connected to the outputs of the position sensors, and two electronic keys, the control inputs of which are connected to the outputs of the flip-flops, and the switching circuits - to the inputs of the counting recorder and to the output of the acceleration sensor.