SU757988A1 - Device for measuring orthogonal components of flow speed vector - Google Patents

Description

The invention relates to the field of measurement technology and can be used in the construction of information-measuring systems and instruments for scientific research, in particular 5 for measuring meteorological parameters of the air environment.

A device is known in which the velocity vector is decomposed into orthogonal components {Ύ]. YU

The disadvantage of this device is the complexity of the constructive execution.

Also known is a device - a sensor of average and maximum wind speed, which contains a converter of wind speed to voltage and an averaging CS filter with a repeater at the output [2].

A disadvantage of this device is low functionality, 20 not allowing to accurately measure the displacement of air masses in time and space.

The aim of the invention is to enhance the functionality and increase the accuracy of the device.

This goal is achieved due to the fact that a power source, a sine-cosine converter, two keys, two bottom filters are inserted into the device;

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their frequencies; the second matching amplifier and the threshold device, and the output of the first low-pass filter through the threshold device is connected to the second input of the control unit, the output of the power source is connected to the third input of the control unit and the input of the sine-cosine converter, each of which is through the lower key and Fltr frequency is connected to the matching amplifier, and the control inputs of the keys are connected to the output of the control unit.

The invention is illustrated in drawing, which shows a diagram of a device that contains a speed converter 1 to a pulse frequency 1, the output of which is connected to the first input 2 of the control unit 3, a sine-cosine converter 4, whose input is connected to the output of the power source 5, and a sinus and cosine outputs via keys 6 and 7, respectively, with inputs of low-pass filters8 and 9. The outputs of the latter are connected to the inputs of matching amplifiers 10 and 11.

Control inputs of keys 6 and 7

merged and connected to output 12

control unit 3. The third input 13

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four

The control unit is connected to the output of the power source 5.

The output of the control unit is connected via the first low-pass filter 14 to the threshold device 15 _{g, the} output of which is connected to the second input 16 of the control unit. five

The power source is a variable voltage generator with a constant amplitude.

The amplitude and phase of the output voltages of the transducer 4 are determined by • functions 5 ° and coz of the angle of rotation of the sensor, i.e. flow directions.

When pulses are received from speed converter 1 at input 2 of control unit 3, the latter produces 15 for each input pulse a sepia of N output pulses with a repetition period equal to the period T of generator 5. The duration of each pulse is T / 2, and its front edge is synchronous 20 from the generator 5 so that it coincides with the moment of transition through O of the output voltages of the converter 4. This operation is carried out with the help of drivers, 25 synchronization circuits, a modulo-N counter and logic circuit.

During each pulse, the keys 6 and 7 are closed, i.e. during the course of each series of N pulses, a single-period phase-sensitive rectification of the output voltages of the converter occurs. The voltage from the output of each of the keys 6 and 7 is eliminated by filters 8 and 9, respectively, and through the matching amplifiers 10 and 11 goes to the output terminals of the device.

The magnitude of the output voltages And _x and IL will be determined by the expressions

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0 _х = к · Ν ίχ · СО5 Οί ι

Yiwu = k * MGK-51po ',

where K is a constant coefficient;

ίχ - pulse frequency output

flow rate sensor 1; 45

l - the angle of rotation of the rotor sensor

flow directions.

The magnitude of ίχ. Is proportional to the modulus of the flow velocity V, therefore, the output voltages will be proportional to .50 orthogonal to the projections of the flow velocity vector on the coordinate axes.

The exact scaling of the output voltages of the device in a wide range of variation of V is carried out by __ by changing the conversion factor N in the control unit 3 by a factor of t.

When V = 0, ίχ = 0 and the zero output voltage of the low-pass filter is 14, the Threshold device 15 at 60 this is in the "lowering" state. The output signal of the threshold device · 15 is fed to the input 16 of the control unit and sets the maximum conversion factor of the counter. 65

In the atom case, the sensitivity of the device turns out to be maximum, since for each pulse from the output of the flow rate sensor 1, the control unit 3 forms a series of Νιπβχ pulses that control the keys 6 and 7.

C These pulses are averaged by the lowpass filter ⁴ 14 and already in the form of a constant voltage are fed to the input of the threshold device 15.

At excess of voltage from the output of the low-pass filter of the 14th threshold

values, the threshold device 15 is switched to the "actuation" state and its output signal switches the circuit for changing the counter conversion factor in the control unit 3.

Its value is set equal. This decreases in

m times the sensitivity of the device, as well as decreases in the w u times the magnitude of the averaged voltage at the output of filter 14. In order in this case the threshold device remains in the same position, the level "lowering" is selected to be (and _cp / w) - di where di the value corresponding to the hysteresis of the automatic switching device of measurement limits.

Claims (1)

Claim A device for measuring the orthogonal components of the flow velocity vector, comprising a matching amplifier and serially connected velocity-to-pulse converter. The control unit, the first low-pass filter, which is due to the fact that, in order to expand the functionality and increase the measurement accuracy, a power source, a sine-cosine converter, two keys, two filters are introduced into the device the lower frequency, the second matching amplifier and the threshold device, and the output of the first low-pass filter through the threshold device is connected to the second input of the control unit, the output of the power source is connected to the third input of the control unit and the input of the sine transform ovatelya, sine and cosine outputs of which each key and through a low pass filter connected to the matching amplifier and the control inputs of keys soedineny- yield control unit.