RU2392641C1 - Acoustic range finding method - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention relates to sound ranging and acoustic control and can be used to measure distance to objects moving inside pipes. The acoustic range finding method involves emission of a probing signal outside a pipe in which an object is moving, reception of the probing signal and emission of a response signal by an active response generating device mounted on the object moving inside the pipe and reception of the reception signal. Emission of probing signal and reception of the response signal are successively carried out from two points spaced apart outside the pipe. The distance between these points is measured. Propagation speed of ultrasound in the medium filling the pipe is then determined by dividing the doubled distance between the first and second point by the two-directional propagation time difference between the object inside the pipe and the first and second points. The distance to the object inside the pipe is determined using the obtained speed value.

EFFECT: reduced measurement error.

1 dwg, 1 tbl

Description

The invention relates to the field of sound ranging and acoustic control and can be used to measure distances to objects moving in the pipe spaces.

A known method of measuring the distance between two points by the method of unidirectional measurement (A.A. Gorbatov, G.E. Rudashevsky "Acoustic methods for measuring distances and control", M .: Energoizdat, 1981, p. 7-9), including the feed an ultrasonic signal from an emitter of an ultrasonic signal installed at one point, receiving an ultrasonic signal by a receiver installed at another point, and measuring the distance between two points by the time the ultrasonic signal travels from one point to another.

There is a known method of acoustic ranging (RF patent No. 2315335 IPC (2006.01) G01S 15/08, published on January 20, 2008), selected as a prototype, including supplying a sounding signal by a first receiving-emitting sensor, receiving this signal by a second receiving-emitting sensor located on a movable in-tube device , supplying a response signal from it, receiving a response signal by a first receiving-emitting sensor, wherein the sounding and receiving response signals are carried out from the outside of the pipe and determining the distance between the two receiving-emitting radiation sensors by measuring the bi-directional transit time of the probe signal and the response signal.

A disadvantage of the known methods is the high error in determining the distance to the in-tube object, due to the dependence of the propagation velocity of the ultrasonic signal on temperature, pressure and the composition of the medium filling the pipeline.

The objective of the invention is to provide a method of acoustic ranging, which allows to reduce the error of measuring distances to objects moving in the pipe spaces.

The problem is solved due to the fact that in the method of acoustic ranging, including supplying a sounding signal from the outside of the pipe to an object moving inside the pipe, receiving a sounding signal and supplying a response signal with an active response generating device located on the in-pipe object, receiving a response signal, determining distance to the object by measuring the time of bidirectional passage of the probing and response signals.

According to the invention, the probing and receiving response signals are sequentially carried out from two points spaced from each other on the outside of the pipe, the distance between these points is measured, then the ultrasound propagation velocity in the medium filling the pipe is determined by dividing the doubled distance between the first and second points by the difference the bidirectional signal propagation time between the in-tube object and the first and second points, using the obtained speed value, determine the distance to the inside tritar object.

By sequentially supplying probing signals and receiving response signals from two points spaced from each other on the outside of the pipe, measuring the distance between these points, determining the speed of ultrasound propagation in the medium filling the pipe, by dividing the doubled distance between the first and second points by the difference in bidirectional time the propagation of signals between the in-tube object and the first and second points, and using the obtained speed value to determine the distance to the in-tube object , it is possible to increase the accuracy of measuring distances to objects moving in the pipe spaces.

The drawing shows a structural diagram of a device that implements the proposed method.

The table shows the results of measuring the removal of the in-tube object from the first acoustic range finder.

An acoustic ranging device that implements the proposed method (see drawing) contains a control unit 1, a first range finder 2 installed at a first point on the outside of the pipe 3, a second range finder 4 installed at another point on the outside of the pipe 3 and an active response generating device 5 mounted on the in-pipe object 6, movable in the in-pipe space.

The control unit 1 is connected to the first range finder 2 mounted on the outside of the pipe 3, and the second range finder 4 mounted on the outside of the pipe 3 at a fixed distance from the first range finder 2.

The control unit 1 can be performed on any microprocessor, for example, ATMEGA 8, rangefinders 2 and 4 must be acoustic, for example, according to RF patent No. 2315335 IPC (2006.01) G01S 15/08, the device for generating an active response 5 can be selected from the RF patent No. 2315335 IPC (2006.01) G01S 15/08. As an in-tube object, an in-line scraper or sealant may be selected.

First, the control unit 1 issues an enable signal to the first range finder 2, which feeds a probing signal to the in-pipe object 6, moved inside the pipe 3, and receives a response signal from the active response generating device 5 located on the in-pipe object 6. After receiving the response signal, the first range finder 2 determines the time of the bidirectional propagation of ultrasound to the in-tube object 6 and transfers it to the control unit 1. Then, the control unit 1 issues an enable signal to the second range finder 4, which feeds the probe signal to the in-tube object 6, moved inside the pipe 3, and receives a response signal from the active response generating device 5, located on the in-tube object 6. After receiving the response signal, the second range finder 4 determines the time of the bidirectional propagation of ultrasound to the in-tube object 6 and transmits it to the control unit 1. The control unit 1 calculates the propagation velocity of ultrasound in the medium filling the pipeline according to the formula:

where t ₁ is the time of bi-directional propagation of ultrasound from the first range finder 2 to the in-tube object 6,

t ₂ - time bi-directional propagation of ultrasound from the second range finder 4 to the in-tube object 6,

L is the distance between the first 2 and second 4 rangefinders.

After that, the control unit 1 uses the calculated speed to calculate the distance to the in-pipe object.

Tests of the acoustic ranging method were carried out at a laboratory bench. The length of the pipe was 4.2 meters; the diameter of the pipe was 0.3 meters. The pipe was installed vertically and was filled with water. The device for generating an active response 5 was located on the simulator of the in-tube object. The simulator was made in the form of a cylinder with a diameter of 0.28 meters and a length of 0.3 meters. Movement of the simulator inside the pipe was carried out using a rope on which the markings were applied in increments of 0.05 meters. A mechanism was installed at the upper end of the pipe, which allows the rope simulator to raise and lower the simulator of the in-pipe object. The first 2 and second 4 range finders were installed at a distance of 1 m from each other, and the second range finder 4 was installed closer to the simulator of the in-pipe object 6. The control unit 1 determined the distance between the second range finder 4 and the simulator of the in-pipe object 6, first in the water and then in saline solution.

The results of bench tests of the acoustic ranging method shown in the table show the possibility of measuring the distance by this method in various environments with high measurement accuracy. The error of distance measurement does not exceed 0.02 meters in the range from 0.5 to 3.0 meters. The error in measuring the distance of the prototype is 0.04 meters, which is two times more than the proposed method.

Range measured by tape measure (m) Rangefinder reading in water (m) Indication of a range finder in saline solution (m) Maximum absolute measurement error (m) The measurement error of the prototype (m) 3.0 3.02 3.01 0.02 0.01 2.5 2,50 2,51 0.01 0,03 2,3 2.29 2,31 0.01 0.04 1.7 1.71 1.72 0.02 0.02 1.3 1.29 1.3 0.01 0,03 0.9 0.89 0.89 0.01 0.01 0.5 0.51 0.49 0.01 0.01

Claims (1)

An acoustic ranging method, including supplying a sounding signal from the outside of the pipe to an object moving inside the pipe, receiving a sounding signal and supplying a response signal with an active response generating device located on the in-pipe object, receiving a response signal, determining a distance to the object by measuring the time of the bidirectional sounding passage and response signals, characterized in that the supply of the probing and reception of the response signals are sequentially carried out from two spaced x from each other points on the outside of the pipe, measure the distance between these points, then determine the speed of propagation of ultrasound in the medium filling the pipe by dividing the doubled distance between the first and second points by the difference of the bidirectional signal propagation time between the in-tube object and the first and second points using the obtained speed value, determine the distance to the in-tube object.