SU915034A1 - Device for measuring distance - Google Patents

Description

The invention relates to radio measuring technique and can be used in systems for measuring the parameters of movement of objects and in radar.

A device for measuring the range, containing a series-connected reference generator, amplitude modulator, power amplifier, transmitting antenna, transponder, receiving antenna, receiver, amplitude detector, first phase detector, the output of which is connected to the input of the computing unit, the second output of the reference oscillator; not with the second input of the amplitude modulator and the second input of the first phase detector [1

However, the known device has a limited range accuracy.

The purpose of the invention is to improve the accuracy of distance measurement.

2

This goal is achieved by the fact that the device for measuring the range, containing serially connected reference oscillator, amplitude modulator, power amplifier, transmitting antenna, transponder, receiving antenna, receiver, amplitude detector, first phase detector, the output of which is connected to the input of the computing unit, the second the output of the reference generator is connected to the second input of the amplitude modulator and the second input of the first phase detector, additionally N phase modulators, N phase detectors, N scale blocking units, where the inputs of the N phase modulators and the reference inputs of the N phase detectors are connected to the second output & home of the reference generator, the output of each phase modulator is connected

with the corresponding signal input!

phase detector, N phase outputs

detectors connected to the corresponding>. 915034 4

inputs of the computing unit and through the corresponding scaling units with control inputs of the corresponding phase modulators.

The drawing shows a structural electrical diagram of a device for measuring range.

The proposed device contains a series-connected reference generator 1, amplitude modulator 2, power amplifier 3, transmitting antenna 4, transponder 5, receiving antenna 6, receiver 7, amplitude detector 8, perchy phase detector · 9, N scaling units 10 (10-1 , 10-Ν), N phase modulators 11 (11-1 ... 11-Ν), N phase detectors 12 (12-1 ... 12-19) and the computational unit 13 ·

The device works as follows.

The reference generator 1 generates oscillations P of the modulating signal (for example, in a quartz oscillator with a frequency of 5? = 2 L D) and by multiplying by a harmonic generates carrier frequencies ω = 2 I, which are fed to amplitude modulator 2; The amplitude-modulated oscillations are amplified in the power amplifier 3 and radiated by the transmitting antenna 4 in the direction of the object. The facility has a transponder 5 that relays the oscillations in the direction of the receiving antenna 6 and the receiver 7, from the output of which the amplitude-modulated voltage is fed to the amplitude detector 8. At the output of the amplitude detector 8, there are oscillations of a low-frequency modulating signal, the phase shift of which contains the range information and arrive at one of the inputs of the first phase detector 9, to the second input of which a low frequency voltage is supplied from the reference generator 1. The output of the first phase detector 9 is energized e is supplied to the computing unit 13 input and through the first scaling unit

10-1 (for example, made in the form of a voltage divider) to the control input of the first phase modulator

11-1, with the output of which the oscillations of the frequency Gs with a phase shift proportional to the control voltage and, consequently, the measured distance, are fed to the signal input of the first 12-1 of the entered N phase

detectors 12. The low-frequency reference voltage from the reference generator 1 is supplied to the reference input of this phase detector 12-1. At the output

5, a phase detector 12-1 is allocated a voltage proportional to the phase difference between the reference oscillation and the oscillation supplied from the first phase modulator 11-1. This voltage is applied to the computing unit 13 and through the second scaling unit 10-2 to the controlled input of the second phase modulator 11-2. Subsequent phase modulators

15 11 ~ 3 ··· 11 “Ν and phase detectors

12-2 ... 12-Ν in the device work as described.

In computing unit 13, the output voltages from all phase detectors 9, 12 are summed up, and the distance to the object is determined from the well-known characteristic of phase detectors 9 and 12. Since the phases of the signals located on each of the signal inputs of each detector 9 and 12, proportional to the measured range, then the voltage at the outputs of each phase detector 9 and 12, and, therefore,

30 and the total voltage is proportional. measured range. The mode of operation of each of the phase modulators 11 is set so that the average (constant) phase values of the signals at the outputs of these modules ⁵⁵ tori 11 are equal in magnitude to the average (constant) value of the phase of the signal at the output of the amplitude detector 8. The mode of operation of the modulators 11 is determined by the choice

4 ° transfer coefficients of scaling units 10.

When changing the measured range, there is a corresponding change in the phase of the signal at the output

^{45 of the} amplitude detector 8. This in turn leads to a change in voltage at the output of the first phase detector 9, and, consequently, to a corresponding change in phase

5® signal at the output of each phase modulator 11. Changing the control voltages at the outputs of scaling units 10 in one direction, and therefore the voltage of the ⁵⁵ equal to the sum of all output voltages from the phase detectors 9 and 12,

changes. in accordance with the change in the distance to the object.

915034

In the proposed device, arithmetic addition of average values of voltages from the outputs of all phase detectors 9 and 12 occurs. The fluctuation fluctuations, which determine the measurement errors, are added geometrically due to their weak statistical dependence. This improves the accuracy of measurements. YU

Let the device use Ν + 1 identical phase detectors 9 and 12, N identical scaling units 10 and N identical phase modulators 11. Then the sum of the average 15 voltages from the outputs of the phase detectors 9 and 12 is equal to

^mi out “Om) υ | (“ χ,

where and _LYH1 - the voltage at the output of the first 20 phase detector 9 ',

“ ^Nap R ^I * Vnie at the output of each of the additionally introduced phase detectors 12. 25

The variance of the total fluctuations is determined by the expression

Where - the variance eg ^l zheniya fluctuations in the output of the first

phase detector 9, bu - the variance of the voltage fluctuations at the output of each of the input phase detectors 12.

RMS value of measurement error in this case

equally

zo

35

40

K (And + 1)

where K is the steepness of the characteristics of the phase detector 9 and 12.

In the known device for measuring the range with one phase "detector 9, the output voltage at the output of the first phase detector 9

g ( _{q d} ),

where K «is the steepness of the detector (.44)

Characteristics of the first 9 ”phase detector

dC - informational phase shift.

'Then, the rms error of phase shift measurement

n general

^υ 4 ^ “~ to- ' ^where " The rms value of the voltage fluctuations at the input of the first phase detector 9 (fluctuations of the oscillations caused by various factors during the propagation of radio waves in space, the fluctuation noise of the transponder, receiver, etc.).

Now you can determine the gain of the proposed system $ by the criterion of reducing the error (improving the accuracy) of the measurement.

K (NP)

A 'and _H6 ¹¹

In that case, when

Therefore, in the proposed device, an increase in the accuracy of measuring the range is achieved in γ P ³³ · To increase the measurement accuracy, it is necessary to increase the number N of additional blocks and nodes. However, in practice, the requirements of overall weight characteristics, reliability of mutual influence, etc. do not allow in real systems to infinitely increase the number of а, and therefore "increase ~ yes infinity measurement accuracy

range. As a rule, the decision is made from compromise conditions for ^: performing the main task in the particular ¹ · case.

Thus, the proposed device for measuring the range allows to increase the accuracy of the measurement range.

,

Claims (1)

Claim A device for measuring the range, containing series-connected fporny generator, amplitude MODULATOR *, POWER AMPLIFIER1, transmitting antenna, transponder, receiving antenna, receiver, amplitude detector, first phase detector, the output of which is connected to the input of the computing unit, the second output of the reference generator is connected to the second input of the amplitude modulator-torus and the second input of the first phase 7. .9150 * 4 8 ' In order to improve the accuracy of measuring the range, N phase modulators, N phase detectors, N scaling blocks were introduced, the inputs of N phase modulators and the reference inputs of the N phase detectors were connected to the second output of the supports of the generator, The output of each phase modulator is connected to the signal input of the corresponding phaeo detector, the outputs of the N phase detectors 10 tori connected to the corresponding inputs of the computing unit'i through the appropriate scaling units - with the control inputs of the corresponding phase modulators.