SU819767A1 - Range finder system with measurement of phase difference at the modulation frequency - Google Patents

Description

(54) A FINE-DIMENSIONAL SYSTEM WITH MEASURING THE DIFFERENCE OF PHASES AT THE FREQUENCY OF MODULATION The drawing shows a structural electrical circuit of the distance measuring system with a measurement of the phase difference at the modulation frequency. The proposed rangefinder system contains ground-based and on-board 2 stations, while the receiver receiver is 2, holds the transmitter-receiver antenna 3 transmitter 4, receiver 5, reference frequency generator 6 and indicator 7 deviations, frequency divider 8, variable block 9 the delay, the IQ block of statistical processing of a reliable signal, the frequency divider 8 being connected between the output of the reference frequency generator 6 and the input of the transmitter 4, and the output of the receiver 5 is connected to the indicator 7 of the deflection through the variable delay block 9 and block 10 of statistical processing of reliable signals. Block 10 of statistical processing of preemptive signals contains two shaper 11, 12 pulses, two coincidence circuits 13, 14 and averaging. differential-differential link 15, with some Bxojtsa circuits 13, 14 coinciding with the output of the reference frequency generator b, and others with Shz1 of the series-connected serial formers 11, 12 pulses, and the outputs of the co-operation circuits 13, 14 connected with the integrating inputs of the averaging differential differential link 15. Ground transceiver station 1 includes a transceiver antenna 16, a receiver 17 and a transmitter 18.. The system works as follows. A pulse is received at the modulation input of transmitter 4. from the generator. 6 reference frequency through a frequency divider 8. The frequency of the pulses corresponds to the modulation frequency. From the impulses of the reference frequency in transmitter 4, a sinusoidal signal is earned that modulates COOT to the insignificant high-frequency oscillations. The modulated high-frequency oscillations are radiated by the transmitting-transmitting antenna 3 and are fed through the antenna 16 to the input of the receiver 17. In the receiver 17, a modulation is often allocated that modulates the natural frequencies of the transmitter 18 different from the high-frequency oscillations of the transmitter 4. Modulated high-frequency oscillations of the ground station. 1, emit- An antenna 16 is received by antenna 3 and fed to the input of receiver 5. In the receiver 5, a modulation frequency is allocated, and at the moment of transition of this signal through the zero line, a reference pulse is transmitted, which is fed to the input of a variable delay unit 9. The variable charge unit 9 carries out a pulse shift within the length of the pulse period of the reference frequency generator 6. The leading edge of the output pulse of the time delay unit 9 is the pulse former 11, the output pulse duration of which is equal to the pulse duration of the reference frequency generator 6. This pulse arrives at the inputs of the coincidence circuit 13 and the second pulse driver 12, the latter being triggered on the falling edge of the input pulse. The duration of the output pulse of the driver 12, which is fed to the coincidence circuit 13, is also equal to the pulse duration of the reference frequency generator 6. The second inputs of the circuits 13 and -14 coincidence receive the pulses of the reference frequency generator 6, the initial pulses from the matching circuits 13 and 14, the duration of which is proportional to the time interval of the pulses of the formers and the reference frequency generator 6, arrive at the integrating inputs of the statistical processing unit 10 with differential-differential link 15, where the signals from the integrating circuits are statistically averaged over a selected period of time and compared at the differential differential link 15. The output signal with the differential The difference link 15 is fed to the input of the deviation indicator 7. At the time of calibration with the help of variable delay unit 9, the strobe pulses are combined with the form of oil springs 11, 12 with one of the next in frequency pulses of the reference frequency generator 6. In this case, pulses are received from circuits 13, 14 on the integrating circuits. The equality of the duration of the output pulses from the circuits 13, 14 coincides only at the time of half-overlapping of the pulses of the reference frequency generator 6 with the pulses of the formers 11, 12 .. This corresponds to the equality of the input voltages on the integrating circuits and the statistical processing unit 10, the output blocks 10 statistical processing with a differential-difference link 15 automatically establishes a conditional zero. This corresponds to the selected movement path. When the movable object deviates from a predetermined path in the time interval, a pair of strobe pulses from the formers 11, 12 pulses shifts. The equality of the duration of the output pulses from the circuits 13, 14 coincidence is violated and, therefore, information on the magnitude and direction of deviation of the moving object from the predetermined path appears at the input of the unit 10 for statistical processing of reliable signals.

Thus, in the rangefinder system, using the frequency divider 8 and variable delay block 9, the measured time interval, proportional to the distance to the object, is reduced. up to a value equal to the duration of the pulses of the reference frequency generator 6. in reducing information about the movement of the object. The accuracy of the rhenium measurement in this case is greatly enhanced by reducing the stability requirement of the variable delay unit 9. In addition, such a construction of the system makes it possible to create constructively simple blocks of variable time delay.

The reduction of the measured time interval to the pulse duration of the reference frequency generator 6 pos-. It is possible to perform statistical processing not of the entire time interval proportional to the distance to the object, but only the instant of coincidence of the pulses generated in block 10 of the statistical processing of the secondary signals with the generator pulses b of the reference frequency. Emissions into impulse noise in this case are not statistically processed, since if they are present, the specified time-combination of impulses does not occur. Only reliable information is processed. Studies have shown that the coefficient of error averaging at. statistical processing of information, the measurement accuracy using the proposed device will increase by N / 3 times, where N is the number of statistically processed measurement cycles. .

The noise immunity of the rangefinder system is significantly increased due to the fact that the probability of the occurrence of interference within the allowed interval is small and equal to the ratio of the duration of the pulses of the reference frequency generator 6 to the period of the modulation signal.

When using a rangefinder system to drive an aircraft along equidistant trails, the pilot chooses a route, which he follows, by means of a variable block for the delay. If desired, the aircraft control process can be automated by equidistant routes, and the route selection is pre-programmed on the ground, in this case, the deviation indicator is linked to the autopilot system and, through the program input unit, to the variable delay unit.

The range system can also be used for the automatic driving of tractors, dredgers and other moving objects, and greater accuracy is required for maintaining the direction of travel.

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The range system allows you to control mobile objects with an error of deviation from the specified route ± .1, in areas saturated with radio electronic means, which improves the quality of the work performed.

Claims (2)

1. A distance meter system with phase difference measurement at a modulation frequency of 0, comprising a ground and airborne transceiver station, while the airborne transceiver station contains a transceiver antenna, a transmitter, a receiver, a reference frequency generator and a deviation indicator, 5 is different with the fact that, In order to improve noise immunity and measurement accuracy, a frequency divider, a variable delay unit and a statistical processing unit of reliable signals are entered into the onboard transceiver station, the frequency divider being switched on by the output of the reference frequency generator and the input of the transmitter, and the receiver’s output is connected to the deviation indicator through variable delay unit and statistical signal processing block. 2. The system according to claim 1, characterized in that the statistical processing unit of reliable signals contains two pulse shapers, two coincidence patterns and an averaging differential-difference link, with one of the inputs of the coincidence circuit connected to the output of the reference-frequency generator, others are connected to the outputs of series-connected pulse formers, and the outputs of the coincidence circuits are connected to the integrating inputs of the averaging differential-difference link. Sources of information taken into account in the examination 1. Astafyev, G.P., et al. Radio5, navigation aids of aircraft.-M., Sov. radio, 1962, p. 263 (prototype). / -Tf- i L.IIIJ