SU1233058A1 - Apparatus for discrete measurement of signal frequency of laser doppler navigator - Google Patents

Abstract

This invention relates to the field of radio engineering. The purpose of the invention is to improve the accuracy of signal frequency measurement. The device contains circuits, each of which consists of a filter 1. Introduction of 2 impulses packs to the device of the driver, the generator of 3 stop pulses, the start driver 4 of the start pulses, the switch 5 - the start of the pulses, the switching control unit 6, the switch 7 of the stop pulses and the switch 8 packs of pulses in each circuit, as well as the adder 9 start impulses, adder 10 stop impulses, adder 11 bursts of impulses, unit 12 for controlling start-impulse commutation, meter. 13 time intervals and a 14-pulse counter with the formation of new connections between the elements of the device eliminates the influence of the switching circuit on the operation of filters, 2 or i (L o w o C o p 00

Description

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1233058

The invention relates to radio engineering and is intended for use in laser Doppler measurements of velocity,

The purpose of the invention is to increase the accuracy of measuring the frequency of the signal by the unit of exclusion of the influence of the switching circuit on the operation of filters,

Fig, 1 shows the block diagram of the device; Fig. 2 shows temporary diagrams explaining the operation of the device.

A device for discrete measurement of the frequency of a laser Doppler waveform measuring device contains N parallel circuits, each of which consists of filter 1, a former 2 packs of pulses, a generator of 3 stop pulses, 4 start-pulses, a start-pulse switch 5, unit 6 switching control, switch 7 of stop pulses and switch 8 bursts of pulses, the device also contains an adder 9 start-up pulses, an adder 10 stop-pulses J adder 11 bursts of pulses, unit 12 control start-up pulses, meas 3 timeslot counter and 14 mp pulses.

The device input is connected to the inputs of N filters 15 and the output of each of the N filters is connected to a driver of 2 packs of pulses, to the output of each of the N drivers of 2 packs of pulses connected switchboard 8 packs of impuls, series-connected driver of 4 start-pulses and switch 5 start-pulses and sequentially connected driver of 3 stop pulses and switch 7 of stop pulses, the code of some of the K switch start pulse signals is connected to the input of the corresponding switching control unit 6, and the output of each of M b The switching control grids 6 are connected to a different input of each of the I switches; 8 bursts of pulses and to a different input of each of the N switches; 7 stop pulses; the output of each of the N switches; 7 stop pulses connected to a different input of each of the N switching control blocks 6, code Each of the N switchboards 5 start-up pulses is connected to the corresponding input of the start-up adder 9, the output of which is connected to the input of the start-pulse switching control unit 12

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and to the start-impulse input of the meter 13 time intervals, the output of the start-impulse switching control units 12 is connected to a different input of each of the N 5 start-impulse switches, the code of each of the stop-pulse switches 7 i is connected to the corresponding input of the adder 10 stop-pulses whose output is connected to the input of stop-pulses of the meter 13 time intervals and to another block 12 of the control of switching of start-pulses, the output of each of the N switches 8 packs of pulses is connected to the corresponding input of the adder 11 PA pulses, the output of which is connected to the input f of the counter G4 pulses.

The input signal is formed when the aerosol or natural piet particles pass through the measuring volume of a laser Doppler velocity meter, which is the intersection zone of two coherent laser beams. An interference pattern is formed in the intersection zone of the beams. The light scattered by the particle passing through the measuring volume gets to the input of the photodetector, the output of which repeats the distribution of the illumination in the measuring volume

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And - output signal at the maximum. Low Frequency component sig / 4-2 pitch 1 L ....

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The ba-sis carries information about the Doppler frequency in, which depends on

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The device works as follows

The signal from the photodetector of the laser Doppler velocity meter of FIG. 2a at a random moment of time arrives simultaneously at the inputs of all N filters 1 crossing the required frequency range and generates a response in filter 1 whose passband corresponds to the frequency

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filling the arriving signal pulse (Fig. 28. This is how the signal is cleared from noise, i.e. filtering the useful signal, which improves the accuracy of measuring the frequency of the signal. In filters 1, which transmit the useful signal, Since the responses are due to the low frequency component of the laser signal of the Doppler velocity meter (Fig. 2b), these responses are also false signals, but at the outputs of the corresponding filters 1 these responses appear later than the useful signal, because filters 1 have 15 a large time constant and the signal in them grows more slowly, Useful and spurious signals. With the outputs of filters 1, they arrive at the inputs of the corresponding formers of 2 bursts of pulses, at 20 outputs of which bursts of pulses are formed corresponding to the useful (Fig. 2g and false) 2 of the signals .. Packs of pulses from the outputs of the formers 2 packs of pulses are received at the 25 inputs of the formers 4 start-up pulses and formers 3 stop-pulses. An example of the practical implementation of a 2-pulse generator shaper, a 4 start-pulse shaper, and a 3-stop stop ZOR shaper, can be a two-channel amplitude analyzer and a measuring interval used in the known device. The first at the output of the corresponding start-up shaper 4 is a start-pulse of the useful signal (FIG. 2e) passing through the open start-pulse switch 5, for which 40 can be used, for example, a key, and Blocking up

ka 6 switching control. As the switching control unit 6, for example, a trigger can be used. The switching control unit 6 generates a control signal (FIG. 2k), which arrives at the stop pulse switch 7 and the 8 pulse packets at the switch 8 and opens these switches. As switches and 8-, for example, keys can be used. A stop-pulse (fig. 2) arrives at the open switch 7 of stop pulses at the end of the burst. Start-up pulses generated in the channels of useful and spurious signals, from the inputs of the corresponding

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switches 5 start pulses are delivered to the adder 9 start pulses. The first through the adder 9 start-up pulses passes the start-pulse of the useful signal (FIG. 2c) and the triggering signal is generated. switching control unit 12, which can be used, for example, a trigger, switch control unit 12 generates a control signal (FIG. 2l), which goes to all N blocks 5 by switching start-impulses and locks them. Thus, through the switch 5 start-pulses passes only the first start-pulse, t, e. the start-pulse of the useful signal, and the start-impulses of spurious signals through the locked switches 5 of the start-impulses do not pass through the corresponding blocks of the switching control b and do not cause them to trigger. Corresponding to false signals, switches 7 of stop pulses and switches 8. of bursts of pulses. Are locked and do not skip stop pulses (fig, 2k) and bursts of pulses (fig. 2a) of false signals. The start-pulse of the useful signal from the output of the adder 9 start-impulses is fed to the meter time interval 13 n starts it. .-Simultaneously from the output of the corresponding switch 9 bursts of pulses per sum-. Matrix of 1 bursts of pulses. A batch of pulses enters, corresponding to To the signal, From the output of the adder IG of the pulse bursts, the pulse batch arrives at the pulse counter 14, which counts the number of pulses in the liMnyjibcoB burst. At the end of the pulse packet of the switch 7 stop impulses corresponding to a useful signal, the stop impulse 10 receives a stop impulse (FIG. 2, which passes the stop adder 10 and then enters the stop impulse input of the time meter 13, equilibrium measurement of the time interval Thus, at the output of the time 13 measurer, information appears on the magnitude of the time interval and the end between the start-pulse and the stop-pulse, and at the output of the pulse counter there is information on the number of pulses in the packet. All information is received by external devices, for example, an electronic computer, where you are going, -,

calculation of the frequency of the measured signal55

but. A stop pulse from the output of the commutator 7 from the top pulse f is fed to the switching control block 6, which returns to the initial state and 5 locks the switches 7 and 8. The stop pulse from the output of the stop 10 adder pulses to the start switch control block 12 -pulses, which unlocks all K switches 10 start-impulses. After that, the device is ready to receive and process the next signal pulse, which came at any frequency within the frequency band 15 of the overlapped devices.

F o rmu l invention

A device for discrete measurement .-. 20 nor a frequency of a laser Doppler velocity meter signal containing filters, characterized in that, in order to improve measurement accuracy, N 25 shapers of pulse shapers, N stop formers, N shapers are entered into it Start-up pulses, Start-up switches, N-packs of impulses, N control units, 30 commutation, start-, impulses adder, stop-adder, impulse adder, start-impulse switching control unit, meter variables intervals and the pulse counter 35, the input device is connected to inputs of M filters, and to the output of each filter is connected hf pulse packet shaper, Yield .N each of die 40 is connected rovateley burst,

with a switch input of a pulse train with serially connected start-pulse driver and a start-pulse switch and with a serially connected stop-pulse driver and a stop-switch switch, the output of each of the N start-up switches is connected to the input of the corresponding switching control unit, and the output of each from N switching control blocks, connected to the second input of each of the N switching blocks of the pulse train and to the jBTOpOMy input of each of the N switches of the stop pulses, the output of each N stop-stop switches Connected to the second input of each of the N switching control units, the output of each of the N co-drivers of start-impulses is connected to the corresponding input of the adder, the start of pulses, the output of which is connected to the input of the start-impulse switching control unit and the start input -pulses of the time interval meter, the output of the control unit for switching start-impulses is connected to the second input of each of the .H switching blocks, the output of each of the N switches of the stop-pulse is connected to the corresponding The progress of the stop-pulse adder, the output of which is connected to the stop-pulse input of the time interval meter and to the second input of the switching control unit, the output of each of the switches of the pulse train is connected to the corresponding input of the pulse packs, the output of which is connected to the input of the pulse counter.

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Claims (1)

Claim A device for discrete measurement of the frequency of a signal of a laser Doppler speed meter, containing filter I, characterized in that, in order to increase the accuracy of measurements, N 25 pulse train shapers, N stop pulse shapers, H start shapers are introduced into it pulses, K start-pulse commutators, N pulse-packet commutators, N commutation control units, 30 start-and-pulse adder, stop-pulse adder, pulse-pack adder, start-pulse commutation control unit, time meter intervals and 35 counts of pulses, with the input of the device connected to the inputs of N filters, and a pulse shaper connected to the output of each of the N filters. The output of each of N pulse shapers is connected to the input of the pulse packet commutator and connected in series by the start-pulse shaper and the start-pulse switch and with the stop-pulse shaper and the stop-pulse switch connected in series, the output of each of the N start-pulse switches is connected to the input of the corresponding switching control lock, and the output of each of the N switching control blocks. connected to the second input of each of the N blocks of switching bursts of pulses and to the second input of each of the N switches of stop pulses, the output of each of the N switches of stop pulses is connected to the second input of each of the N blocks of control pulses, the output of each of the N switches of start pulses connected to the corresponding input of the start-pulse adder, the output of which is connected to the input of the start-pulse switching control unit and to the start-pulse input of the time interval meter, (the output of the start-imp switching control unit LSS is connected to the second input of each of the N switching blocks, the output of each of the N stop pulse switches is connected to the corresponding input of the stop pulse adder, the output of which is connected to the stop pulse input of the time interval meter and to the second input of the switching control unit, the output of each of the packet switches pulses connected to the corresponding input of the adder of the pulse packets, the output of which is connected to the input of the pulse counter. .1233058 g _______ SHLLHSHV ___________ d —____ _g ---- fl____ Oh -------- ~ --l-- well 1 3 Jl and fl to----- l l ---- -g --- Ξ _ FIG. 2