RU192302U1 - Pulse receiving device - Google Patents

Abstract

The invention relates to a technique for detecting signals when exposed to interference, for example, in laser ranging or in alarm systems. The pulse receiving device comprises a receiver with a timer defining the limits of the reception working time. In addition, a time mode switch equipped with a time counter and an invalid measurement counter associated with the output of the receiver were introduced, as well as a decisive device included at the output of the invalid measurement counter. The counter of false measurements may include a skip selector and a false alarm selector, which are included at the output of the receiver, while at the input of the skip selector a correct result setter is entered. The technical result consists in reducing the test time while ensuring a minimum scatter of the results and without compromising product life. 1 s.p. f-ly. 2 ill.

Description

The proposed utility model relates to a measurement technique when exposed to interference, for example, in a laser location, long-distance communications or in alarm systems.

Known devices for remote measurements associated with the selection of weak signals [1], which include sensing a remote object with laser pulses, receiving the signals reflected by the object and determining the parameters of the reflected signal, which are used to judge the characteristics of the remote object, for example, the distance to it. The results of such procedures should satisfy the given probability of a reliable measurement.

Known video analysis tools in closed-circuit television systems [2], which detect signals from remote sensors. In this case, it is also required to provide a given probability of correct identification of the signal.

Methods are also known for stabilizing the frequency of false positives at an acceptable level during the measurement process [3].

A feature of these systems are conflicting requirements for the threshold of detection of received signals. On the one hand, this threshold should be as low as possible to ensure maximum sensor sensitivity. On the other hand, the response threshold should be high enough to minimize the likelihood of a false alarm from internal sensor noise and other interference. Thus, the probability of a reliable measurement should be as close as possible to the acceptable limit, which imposes strict requirements on the accuracy of control methods, depending on the volume of tests.

Closest to the technical nature of the proposed device is a pulse receiving device of the laser rangefinder LPR-1 [4], containing a receiver equipped with a timer that sets the limits of the working interval of the reception time. Checking this device for compliance with the requirements for the probability of a reliable measurement is carried out by conducting 10 measurements in the composition of the device, of which at least 9 must be reliable.

With higher requirements for the likelihood of reliable measurement, the required test volume increases significantly, which leads to an increase in the test duration and a reduction in the resource of the tested product.

The objective of the utility model is to reduce test time while ensuring a minimum dispersion of results and without compromising product life.

This problem is solved due to the fact that in the known pulse receiving device containing a receiver with a timer that sets the limits of the working time of reception, a time mode switch equipped with a time counter and an invalid measurement counter associated with the output of the receiver are introduced, and a resolving device is introduced, Incorrect measurements included in the output of the counter.

The counter of false measurements may include a skip selector and a false alarm selector, which are turned on at the output of the receiver, and their outputs are connected to a counter whose output is connected to a resolver, while the correct result setter is entered at the input of the skip selector.

In the drawing of FIG. 1 shows a block diagram of a device. In FIG. 2 is a diagram of a counter of false measurements.

According to FIG. 1, the device contains a receiver 1 with a timer 2 connected to a time mode switch 3 with a time counter 4. An invalid measurement counter 5 is connected to the output of the receiver. The outputs of a time counter 4 and an invalid measurement counter 5 are connected to the inputs of a resolving device 6, the output of which is a pulse output receiving device. The counter of false measurements (Fig. 2) contains a counter 7, at the input of which a skip selector 8 and a false alarm selector 9 are introduced. A correct results dial 10 is connected to the control input of the skip selector.

The device operates as follows.

In the "work" mode, the time mode switch 3 by an external command resets the time 4 and the counter of false measurements 5 and sets the timer 2 to the operating mode T _slave . Thus, when locating a range measurement, the receiver 1 opens for a while [4]

R _max - the upper limit of the range of measured ranges; c is the speed of light.

Example 1

R _max = 10000 m. T _slave = 6.7⋅10 ^-5 s.

In this case, the operation of the photodetector is considered true and issued from the receiver 1 to external devices for recording measurement results.

In the "control" mode, the time mode switch, by an external command, resets the time counter 4 and the counter of invalid measurements 5 and puts the timer 2 in the control mode _Tcont . Time _Tcont selected from conditions

M _cont - the average number of unreliable measurements during the time T _cont ;

p is the given probability of an unreliable measurement during the time T _slave ;

M _ol - the acceptance number of unreliable measurements.

- доверительный коэффициент.

- confidence coefficient.

With a minimum value of M _CR = 1 from (3) follows

Where

Substitution of (4) into (2) gives the condition

Example 2

=3; T_раб=6,7⋅10^-5 с.p = 0.01;

= 3; T _slave = 6.7⋅10 ^-5 s.

Q = 5.5.

M _cont = 10.9.

In this case, the time of checking the probability of false measurements

T _cont = T _slave M _cont / p = 0.073 s.

Inaccurate measurements may separately account for omissions and false alarms. To do this, a skip selector and a false alarm selector can be entered on the receiver’s output, and their outputs are connected to a counter, the output of which is connected to a resolver, and a correct result generator is entered at the input of the skip selector.

When conducting tests according to a known method, the number of measurements

N _cont = M _cont / p. In the conditions of example 2, the volume of the control series N = 1090. With a measurement frequency of 1 Hz, the test time would take 1090 seconds, i.e. about 20 minutes. In addition, with this method of verification, the resource of the entire device is consumed, and not just the receiving path subject to monitoring.

Thus, the task has been achieved - reducing test time while ensuring a minimum dispersion of results and without compromising product life.

Information sources

1. Bosk. Using lasers to measure distances. "Foreign Radio Electronics", 1964, No. 3.

2. Guidelines R 78.36.030-2013. Application of video analysis software in CCTV systems.

3. Vilner V.G. Design threshold devices with noise stabilization threshold. // Optical-mechanical industry. - 1984 - No. 5, - S. 39-41.

4. Laser reconnaissance device LPR-1. Technical description and instruction manual. - prototype.

5. Gmurman V.E. Theory of Probability and Mathematical Statistics. M. "Higher School", 1977 - S. 66.

Claims (2)

1. A pulse receiving device containing a receiver with a timer defining the limits of the working time of the reception, characterized in that a time mode switch is provided with a time counter and an invalid measurement counter associated with the output of the receiver, and a decoding device is included that is connected to the output of the counter false measurements. 2. The pulse receiving device according to claim 1, characterized in that the counter of false measurements includes a skip selector and a false alarm selector included at the output of the receiver, and their outputs are connected to a counter whose output is connected to a resolver, while at the input of the skip selector The dial of correct results is entered.

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