JPH04136703A - Traveling position measuring device and method - Google Patents

Abstract

PURPOSE:To prevent an error from being accumulated by detecting connection part of an object to be inspected by an ultrasonic distance meter and calculating traveling distance in reference to each connection part. CONSTITUTION:A propagation time measuring means 4 measures an ultrasonic propagation time T from a transmission signal which is sent and a reception signal and then sends it to a connection part detection means 5. The connection part detection means 5 compares the transmitted propagation time T with a threshold value Th corresponding to a penetration bead due to welding of a connection part of a pipe body 21 which is set to a threshold setting means 6 previously. Then, a distance calculation means 8 for determining if a pig 22 reaches a connection part of the tube body 21 multiplies a traveling time ti by a traveling speed vi of the pig 22 which is measured by a speedometer 10 for obtaining a traveling distance L1 and then sends it to a successive recording means 11. A time counting means 7 clears a counted value of the traveling time ti when a connection part detection signal Pi transmitted and starts to count the traveling time tj newly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a running position measuring device and measuring method for an inspection device that detects changes in shape and defects in long structures such as rails and pipelines. It is related to.

[Conventional technology]

A method of inspecting for shape changes and defects in structures connected over long distances, such as rails and pipelines, is to run an inspection device along the structure and detect abnormalities and defects using ultrasonic transducers, eddy current sensors, etc. For example, Japanese Patent Laid-Open No. 57-22961 and Japanese Patent Laid-Open No. 6
It is disclosed in Publication No. 4-50903 and the like.

The rail inspection method disclosed in Japanese Patent Application Laid-Open No. 57-22961 involves arranging eddy current sensors on each opposing surface of the traveling vehicle that is spaced a predetermined distance from the top, side and upper neck of the rail. While driving the vehicle at high speed,
This method uses eddy current sensors to accurately detect dimensional changes and wave-like friction in each part.

Further, Japanese Patent Application Laid-Open No. 64-50903 discloses a VIG, which is a self-propelled pipe inspection device used for pipeline inspection. This device uses the pressure difference of the fluid in the pipeline to move the inspection device along the pipe axis to accurately inspect abnormalities, defects, or pipe shapes in the pipeline.

When inspecting abnormal or defective parts while running the inspection device along a continuous structure like this,
Along with the condition of abnormal and defective parts.

It is necessary to identify the exact location of the abnormal part, etc. In particular, when inspecting long-distance structures such as rails or pipelines at high speed, it is necessary to record the accurately detected positions of defects, etc. together with their defect signals.

Conventionally, in order to detect the position of abnormal parts etc. in the running direction,
For example, JP-A-64-50903, JP-A-57-7
As shown in Japanese Unexamined Patent Publication No. 5503 or Japanese Utility Model Application No. 62-73255, a contact type odometer having a rotary encoder is used.

In this odometer, a tire-shaped rotating body is brought into contact with the rail or pipe to be inspected, and the position of the inspection device in the running direction is calculated based on an encoder signal output by the rotation of the rotating body. By recording the distance signal measured in this manner in correspondence with the detection signal of the abnormality, etc., the position of the abnormality, etc. in the traveling direction is specified.

[Problem to be disclosed by the invention]

However, in the above-mentioned contact type odometer, the rotating body is brought into contact with the inspection object using a spring mechanism, but when measuring the position of an inspection device running inside a pipeline, for example, it is difficult to weld the piping. The disadvantage was that the rotating body would bounce off uneven surfaces and branch pipes, making it impossible to accurately measure travel distance.

In addition, when the inspection device is running at high speed along the inspection object, the contact part of the odometer will slip, and especially if there is oil on the inside like a pipeline, there will be a lot of slippage. An error will occur in distance measurement.

Especially when measuring long distances continuously,
Even if the measurement error per unit distance is small, the error accumulates during the measurement and becomes large, making it impossible to identify the position of defects that occur in the latter half of the measurement.

Furthermore, when measuring the position of an inspection device running inside a pipeline over a long distance using the contact-type odometer, for example, the presence of irregularities such as pipe welds and branch pipes may cause Another drawback was that excessive repeated loads were applied to the odometer, causing fatigue and damage to the odometer, making it impossible to measure distances.

This invention has been made to solve these shortcomings, and provides a running distance measuring device and a measuring method that can stably measure the running distance of an inspection device and pinpoint the location of defects etc. with high precision. The purpose is to

[Means to solve the problem]

The traveling distance measuring device according to the present invention is a position measuring device that measures the running position of an inspection device traveling along a long inspection object to which a plurality of unit members are connected, and includes: emitting ultrasonic waves to the inspection object; An ultrasonic transducer receives the reflected signal, a propagation time measuring means measures the propagation time of the ultrasonic wave, and compares the measured propagation time with a predetermined threshold to connect the object to be inspected. connection detection means for detecting the connection part; time counting means for counting the travel time of the inspection device and updating the counted value each time a connection part is detected; and the travel distance calculated by multiplying the counted travel time by the travel speed. The present invention is characterized by comprising distance calculation means for calculating.

The running speed for calculating the running distance may be measured by a pair of ultrasonic transducers that are installed at a certain distance in the running direction and alternately transmit and receive ultrasonic waves, or by using a known connection. It may be calculated from the distance between parts and the travel time when traveling that distance.

Further, the long inspection object may be a pipeline to which unit vibrators are connected, a rail to which unit rails are connected, or the like.

Further, the traveling position measuring method according to the present invention emits ultrasonic waves to a long inspection object in which a plurality of unit members are connected, measures the propagation time until receiving the reflected signal, and measures the measured propagation. It compares the time with a predetermined threshold, detects the connection part of the object to be inspected, updates the running time count every time a connection is detected, and multiplies the counted running time by the running speed. The present invention is characterized in that the traveling distance of the inspection device is calculated and the traveling position of the inspection device is specified.

[Effect]

In this invention, the propagation time of ultrasonic waves emitted to the object to be inspected and the time when the reflected signal is received is compared with a predetermined threshold value to detect the connection portion of the object to be inspected. Then, each time a connection is detected, the running time count is updated, and the counted running time is multiplied by the running speed to identify the position of each connection of the object to be inspected, and each identified connection is used as a reference. Calculate the distance traveled.

The running speed for calculating the running distance can be measured by a pair of ultrasonic transducers that are installed a certain distance apart in the running direction and alternately transmit and receive ultrasonic waves, or by measuring the running speed between known connections. By calculating from the distance and the travel time when traveling the distance, the travel speed can be calculated without contacting the test object.

[Example] FIG. 1 is a block diagram showing one embodiment of the present invention.

As shown in the figure, the mileage measuring device has a connection position detection section 1.
and a distance calculation section 2.

The connection position detection section 1 includes a transducer 3 consisting of a pair of a transmitting transducer for transmitting ultrasonic waves and a receiving transducer for receiving ultrasonic waves, a propagation time measuring means 4, and a connecting portion detecting means. 5.

As shown in the configuration diagram of the VIG in FIG. 2, the transducer 3 is attached to the circumferential outer peripheral surface of the VIG 22 running inside the pipe body 21 of the pipeline, and sequentially transmits ultrasonic waves to the pipe body 21. radiate and receive the reflected signal.

The propagation time measuring means 4 measures the propagation time 'r of the ultrasonic wave from the transmitted signal and received signal sent from the transducer 3.

The connection detecting means 5 compares the propagation time T measured by the propagation time measuring means 2 with a threshold value Th preset in the threshold setting means 6, and determines the position of the connection from the welding position of the pipe body 21. Detect.

Further, the distance calculating section 2 includes a time counting means 7 and a distance calculating means 8.
has.

The time counting means 7 receives the clock (i) from the clock signal generating means 9 and counts the running time ti.

When counting this running time ti, the connecting portion detecting means 5
Each time the connection detection signal Pi is received from the terminal 1, the count value ti is updated and counting is started again.

The distance calculating means 8 calculates the traveling distance Li by multiplying the traveling time ti sent from the time counting means 7 and the speed signal vi sent from the speedometer 10. This calculated mileage Li
is sent to the recording means 11 and recorded together with the defect signal detected by the defect detection means 12.

For example, as shown in the block diagram of FIG. 3, the speedometer 10 includes two sets of transducers 31 and 32, and a switching control means 33.
, a propagation time measuring means 34 and a velocity calculating means 35.

The transducers 31 and 32 are, as shown in FIG.
They are placed a certain distance apart from each other in the direction of travel, and alternately transmit and receive ultrasonic waves.

The switching control means 33 switches the transmission and reception of the transducers 31 and 32, and manually sends the transmission signal and the reception signal respectively sent from the transducers 31 and 32 to the propagation time measuring means .

The propagation time measuring means 34 calculates the propagation time of the ultrasonic wave propagating between the distances in the traveling direction of the VIG 22 to 3 and the propagation time in the opposite direction to 2 from the transmitted and received signals. The velocity calculating means 35 calculates the propagation time τ1. calculated by the propagation time measuring means 34. The traveling speed vi is calculated from τ2 and the distance.

That is, the propagation time 1 and τ2 are respectively expressed by the following equations, assuming that the sound speed of the ultrasonic wave is C.

τr = L / (c 10vi) τ, = L/(c-vi) If the sound speed C is eliminated from this equation, it becomes (1/τ,)-(1/τ,) = 2vi/L. Therefore, by measuring the propagation time τ1°τ2 between distances, the traveling speed vi of the VIG 22 can be obtained without contacting the tube body 21.

As shown in FIG. 2, the defect detection means 12 includes a plurality of transducers 23a to 23n installed at appropriate intervals along the circumferential outer surface of the VIG 22 and a data processing section built in the control section 24. An abnormality or defect in the tube body 21 is detected based on the propagation time of the ultrasonic waves transmitted and received by the transducers 23a to 23n.

Note that power is supplied from a power supply section 25 to the control section 24 having the propagation time measuring means 4 and the like and the recording means 11. A buffer body 26 is provided at the head of the big 22, and souffle bar cups 27 which are pressed against the inner surface of the tube body 21 are provided at the front and rear ends. Due to the pressure difference between the front and rear sides of the souffle bar cup 27, the big 22 travels inside the tube body 21.

The operation of the traveling position measuring device attached to the VIG 22 as described above will be explained with reference to the flowcharts of FIGS. 4 and 5.

When the VIG 22 starts running in order to inspect the pipe body 21, as shown in the flowchart of FIG. Transmit ultrasound and receive the reflected signal. The transmitted signal and received signal from the transducer 3 are sent to the propagation time measuring means 4 (step SL).

The propagation time measurement means 4 measures the propagation time T of the ultrasonic wave from the sent transmission signal and reception signal and sends it to the connection detection means 5 (
Step S2). The connection detection means 5 compares the transmitted propagation time 1' with a threshold value Th corresponding to the back wave heat due to welding of the connection part of the tube body 21, which is set in advance in the threshold value setting means 6. Then, it is determined whether the VIG 22 has reached the connecting portion of the tube body 21 (step S3). Then, when the connection part detection means 5 detects the connection part of the tube body 21 (step S4), the connection part detection signal Pi is sent to the time counting means 7 and the recording means 11 of the distance calculation part 2 (step S5).
. The connection position detection unit 1 repeatedly performs this process until the VIG 22 travels the entire distance of the pipeline, and sequentially detects each connection portion of the pipe body 22 (step S6).

On the other hand, as shown in the flowchart of FIG. 5, the time counting means 7 of the distance calculating section 2 also starts counting the clock signal sent from the clock signal generating means 9 at the same time as the running of the big 22 starts, and the running time of the big 22 is t1. is counted and sent to the distance calculation means 8 (step 511). The distance calculating means 8 calculates the traveling distance Li by multiplying the sent traveling time ti by the traveling speed vi of the big 22 measured by the speedometer 10, and sequentially sends it to the recording means 11 (step 512).

In this way, the distance calculation unit 2 calculates the mileage Li of the Big 22.
While detecting, the defect detection means 12 inspects whether or not there is an abnormality or defect in the tube body 21. When the defect detection means 12 detects a defect or the like in the tube body 21, a defect signal representing the size of the defect is sent to the recording means 11.

When the defect signal is sent to the recording means 11 (step 513
), the running distance Li sent from the distance calculating means 8 at that time and the defect signal are recorded (step 514).

These processes are performed by the connection detection means 5 using the connection detection signal P.
This is continued until i is sent to the time counting means 7 and recording means 11 (step 515). When the recording means 11 receives the connection detection signal Pi, it records the traveling distance Li sent from the distance calculation means 8 at that time as a position signal of the connection. - On the other hand, the time counting means 7 receives the connection detection signal Pi.
is sent, clears the 31 value of running time ti,
Recalculate the running time and start counting j (step 3)
16).

The above process is repeated until the VIG 22 travels the entire distance of the pipeline to be inspected (step 517).

After that, the position data and defect data recorded in the recording means 11 are confirmed, and the position of defects etc. in the entire pipeline is determined.
Check the status of defects, etc.

In the above embodiment, the case where the traveling speed v1 is detected by the speedometer 10 consisting of a pair of transducers 31 and 32 has been described, but when the length of each unit pipe constituting the pipeline is known, is the distance between the connections of each unit pipe, and that distance.

The running speed vi of the big 22 can also be detected from the running time t.

Further, in the above embodiment, the position is recorded in the recording means 11 every time the connection part of each unit pipe of the pipeline is detected. However, when the connection part of each unit pipe is detected a certain number of times, By recording the information in the following manner, it is possible to reduce the recording capacity of the recording means 11 when inspecting a very long pipeline.

In addition, although the above embodiment describes the case of inspecting pipeline piping, the same applies to the case of detecting defects in structures that connect unit members such as rails and are continuous over a long distance. Can be applied.

〔Effect of the invention〕

As explained above, this invention compares the propagation time of ultrasonic waves emitted to an object to be inspected and receives the reflected signal with a predetermined threshold value to detect the connection part of the object to be inspected. , while updating the running time count each time a connection is detected, multiplying the counted running time by the running speed to identify the position of each connection of the object to be inspected, and use each identified connection as a reference. Since the traveling distance is calculated in the following manner, when inspecting a very long object, it is possible to reduce errors in the measured value of the traveling distance and prevent the errors from accumulating.

Further, since errors in the measured value of the traveling distance can be reduced, the position of an abnormal part or defect on the object to be inspected can be detected with high accuracy.

In addition, the running speed for calculating the running distance can be measured by a pair of ultrasonic transducers that are installed a certain distance apart in the running direction and that alternately repeat the transmission and reception of ultrasonic waves, or by measuring the running speed using a known connection. By calculating from the distance between the parts and the traveling time when traveling that distance, the traveling speed can be calculated without contacting the object to be inspected.

Since the travel distance of the inspection device can be obtained without contact from this travel speed and travel time, it is not affected by the unevenness of the object to be inspected like a contact-type odometer, and can stably travel long distances. and can be measured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a VIG, FIG. 3 is a block diagram showing a speedometer of the above embodiment, and FIGS. 3 is a flowchart illustrating an example operation. 1; connection position detection unit, 2; distance calculation unit, 3; transducer,
4; Propagation time measuring means; 5; Connection detection means; 6; Threshold value setting means; 7; Time counting means; 8: Distance calculation hand plate;
9; Clock signal generation means, 10; Speed meter, 11; Recording means, 21; Tube body, 22; Pig, 31, 32; Transducer/receiver, 33; Switching control means, 34; Propagation time measuring means, 35
; Speed calculation means.

Claims (1)

[Scope of Claims] 1. In a position measuring device that measures the running position of an inspection device that travels along an inspection object to which a plurality of unit members are connected, an ultrasonic wave is emitted to the inspection object and the reflected signal is received. An ultrasonic transducer that generates waves, a propagation time measuring means that measures the propagation time of the ultrasonic waves, and a connection detection device that compares the measured propagation time with a predetermined threshold value and detects the connection of the object to be inspected. means, time counting means for counting the traveling time of the inspection device and updating the counted value each time a connection is detected; and distance calculating means for calculating the traveling distance by multiplying the counted traveling time by the traveling speed. A traveling position measuring device comprising: . 2. The running position measuring device according to claim 1, wherein the running speed is measured by a pair of ultrasonic transducers that are installed at a certain distance in the running direction and alternately transmit and receive ultrasonic waves. 3. The traveling position measuring device according to claim 1, wherein the traveling speed is calculated from the known distance between the connecting parts and the traveling time when traveling that distance. 4. The running position measuring device according to claim 1, 2 or 3, wherein the object to be inspected is a pipeline in which unit pipes are connected. 5. The running position measuring device according to claim 1, 2 or 3, wherein the inspection object is a rail made up of connected unit rails. 6. In a position measurement method that measures the running position of an inspection device that travels along an inspection object to which multiple unit members are connected, the propagation time from emitting ultrasonic waves to the inspection object to receiving the reflected signal. , compares the measured propagation time with a predetermined threshold value, detects the connection part of the object to be inspected, updates the count value of travel time every time a connection part is detected, and calculates the counted travel time. A traveling position measuring method characterized in that the traveling distance is calculated by multiplying the traveling speed by the traveling speed to specify the traveling position of the inspection device. 7. The running position measuring method according to claim 6, wherein the running speed is measured by a pair of ultrasonic transducers that are installed at a certain distance in the running direction and alternately transmit and receive ultrasonic waves. 8. The traveling position measuring method according to claim 6, wherein the traveling speed is calculated from a known distance between the connecting parts and a traveling time when traveling that distance.