JP2839582B2 - In-pipe inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention is to detect defects such as scratches generated on the inner surface of a pipe such as a heated steam pipe of a power plant, or to inspect the condition of scale attached to the inner surface of a pipe. It relates to an in-pipe inspection device.

B. Conventional technology Conventionally, an in-pipe inspection apparatus that optically inspects the inside of a pipe includes a robot that runs in the pipe to be inspected and a remote control that is connected to the robot via a cable and remotely controls the robot. A control device, a lighting device mounted on the robot for illuminating the front and side of the robot, a TV camera mounted on the robot for imaging the inside of the tube in the direction of illumination by the lighting device, and displaying the inside of the tube imaged by the TV camera It consists of a monitor TV. Then, the state of the inside of the tube is monitored by watching the image inside the tube displayed on the monitor TV.

C. Problems to be Solved by the Invention By the way, in the conventional in-pipe inspection apparatus as described above, as a means for knowing the position of the robot in the pipe, the feeding amount of a cable connecting the robot and its remote control device is measured. By doing so, a method of obtaining an approximate value was adopted.

However, since the cable is flexible, if the robot repeatedly moves forward and backward, or if there are many curved pipes, the cable will meander, bend or bend, and There is a possibility that the position error of the robot obtained from the cable feeding amount is further increased and the position of a defect or the like in the pipe cannot be accurately grasped.

In addition, a target such as a welded portion of a pipe can be found from the image displayed on the monitor TV, and the position can be determined to some extent by collating the position with a pipe design drawing, etc. If the distance is out of the range, the above-described position determination becomes impossible.

In particular, in a heated steam pipe in which a pipe mounting seat is welded to the outer peripheral surface of the pipe and the outer peripheral surface of the pipe including this seat is covered with a heat insulating material, cracks generated in the welded portion of the seat are probed with an ultrasonic probe. In the case of an inspection, there is a problem that even if a crack can be detected, its position cannot be specified accurately.

The technical problem of the present invention is to positively correct the position of a robot and accurately grasp the location of a defect or the like in a pipe.

D. Means for Solving the Problems To be described with reference to FIG. 1 showing an embodiment, an in-pipe inspection apparatus according to the present invention is configured to remotely move a traveling body 2 traveling in a pipe 1 and forward and backward of the traveling body 2. Traveling body control means 6 controlled by an operation command, and command traveling distance calculating means 7 and 8 for calculating a calculated traveling distance of the traveling body 2 based on a remote operation command.
A photographing unit 5 mounted on the traveling body 2 for photographing a predetermined region in the pipe; a display unit 11 for displaying a cursor and a video photographed by the photographing unit 5 in a superimposed manner; The relative distance between the traveling body 2 and the target point 1a is calculated based on the amount of movement of the cursor when the cursor is moved on the display screen to the target point 1a in the pipe, and the previously input target point
By providing the travel distance correction means 8 for correcting the calculated travel distance of the traveling body 2 from the known distance data up to 1a, the calculated relative distance data, and the calculated travel distance data, Solve technical issues.

E. Function The inside of the pipe is photographed by the photographing means 5 while traveling on the traveling body 2, and the in-pipe image is displayed on the display means 11. When the target point 1a is confirmed on the screen, the traveling body 2 is stopped, and known distance data on the screen of the target point 1a is input to the arithmetic and control unit 8.
Then, when the cursor is moved from the reference position to the target point on the screen, the relative distance between the reference position and the target point 1a is calculated. Therefore, the calculated travel distance of the traveling body 2 is corrected from the input designed distance data to the target point 1a, the calculated relative distance data, and the calculated travel distance data. For example, the calculated travel distance is corrected by adding the relative distance data and the designed travel distance data and calculating the deviation between the calculated distance data and the addition result.

In the above sections D and E for describing the configuration of the present invention, the drawings of the embodiments are used for easy understanding of the present invention, but the present invention is not limited to the embodiments.

F. Examples Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram showing one embodiment of an in-pipe inspection apparatus according to the present invention.

Referring to FIG. 1, a robot 2 that moves forward or backward in a pipe-like manner as a test object is disposed inside a pipe 1 to be inspected. The robot 2 includes a driven unit 3 on which a TV camera 5 is installed, and a driving unit 4 that can move in a pipe.
The driven portion 3 includes a central body 3a and a plurality of jacks 3b projecting radially from the central body 3a and separated from and in contact with the inner peripheral surface of the pipe 1.
At the end of the center main body 3a, a TV camera 5 for imaging the front and side in the tube and an illumination device (not shown) for illuminating an imaging site are installed.

The drive unit 4 is composed of a reciprocating pneumatic cylinder 4a for movement arranged at the center, and a plurality of jacks 4b projecting radially from the outer periphery of the cylinder 4a and coming into contact with the inner peripheral surface of the pipe 1, piston rod 4a ₁ of the cylinder 4a is connected to the central body 3a of the follower 3.

The robot controller 6 causes the robot 2 to move forward or backward by a remote operation command. The robot 2 and the robot controller 6 are connected by a signal cable 17. Further, a compressed air supply hose (not shown) is connected to the robot 2, and a jack 3 of the driven unit 3 and the driving unit 4 is driven by a forward or backward command from the robot controller 6.
By operating the cylinders 4b and 4b and the cylinder 4a, the robot 2 can move forward or backward like a tapeworm.

The counter 7 counts up or down the forward or backward command signal output from the robot controller 6, and the content of the counter 7 is taken into the arithmetic and control unit 8. The arithmetic and control unit 8 calculates the traveling distance of the robot 2 based on the count value from the counter 7. Further, the arithmetic and control unit 8 calculates a target point 1a, for example, a relative distance between the welding portion of the pipe 1 and the robot 2 according to the distance correction command input from the input device 9, and calculates the target point 1a input from the input device 9. The actual position of the robot 2 is calculated by adding the distances on the design drawing, and the calculation result is displayed on the monitor TV 11.

The input device 9 has a function of inputting distance data on the design drawing of the target point 1a and a function of setting cursor coordinates as a reference for distance correction on the target point 1a on a screen displayed on the monitor TV 11. doing.

10 is the TV camera 5 mounted on the robot 2 and the cable 12
An image input device connected through the interface fetches image data captured by the TV camera 5 and outputs the image data to the monitor TV 11 and to the image memory 13. The image memory 13 temporarily stores image data from the TV camera 5 for displaying a cursor on the monitor TV 11, and also stores cursor coordinate data.

Reference numeral 14 denotes a camera control device connected to the TV camera 5 via a cable 15. The camera control device 14 adjusts the focus and the aperture of the TV camera 5 and changes the monitoring direction of the TV camera 5 forward or sideways. This is for switching to.

Next, the operation of the in-pipe inspection apparatus of the present embodiment thus configured will be described.

First, when moving the robot 2 in the pipe, a forward or backward command is given to the robot 2 from the robot controller 6. That is, when the robot 2 is moved forward, first, in the state shown in FIG.
The cylinder 4a of the drive unit 4 is moved forward in this state. In with the piston rod 4a ₁ a follower coupled via portions which 3 is also advanced in the same direction (arrow direction). Thereafter, the jack 3b is extended and brought into contact with the inner peripheral surface of the pipe 1, and the driven section 3 is fixed to the pipe 1. Next, the jack 4b of the drive unit 4 is contracted and separated from the inner peripheral surface of the pipe 1, and the cylinder 4a is moved backward to move the jack 4b side relatively in the direction of the arrow in FIG. When the cylinder 4a reaches the retreat end, the jack 4b is extended and brought into contact with the inner peripheral surface of the pipe 1. Hereinafter, the robot 2 is moved forward by repeating the same operation. When the robot 2 is caused to move backward, an operation reverse to the above-described procedure may be performed.

As the robot 2 moves forward or backward, a command signal for forward or backward movement from the robot controller 6 is output to the counter 7 and counted every time the signal is generated. In other words, in the case of advance, it is counted up,
In the case of reverse, it is counted down. The count value of the counter 7 is taken into the arithmetic and control unit 8 at each operation cycle, and the travel distance of the robot 2 is calculated. Here, since the movement amount d per step of the robot 2 is set in advance, the travel distance of the robot 2 can be calculated by multiplying the count value of the counter 7 by the movement amount d. Then, the traveling distance of the robot 2 during the movement is displayed on the monitor TV 11.

By the way, since a cable or the like is connected to the robot 2, a slip occurs during the movement of the robot 2, or the actual distance traveled by the robot 2 and the displayed distance are affected by the influence of noise mixed into the control line. There is a difference between them. Since this error is accumulated as the robot 2 moves, it is necessary to correct the error.

Normally, the length of the heated steam pipe in power generation facilities etc. is several hundred meters
The length of the pipe is generally formed by joining a large number of pipes of the same diameter by welding. Since the welding position of the pipe is clear from the design drawing, the image inside the pipe 1 taken by the TV camera 5 is monitored by the monitor TV.
If it is projected on 11 and monitored, the weld line can be easily observed,
This welding line can be used as a reference for correcting the traveling distance.

Therefore, in this embodiment, the welding line 1a shown in FIG.
Is a target point for distance correction, and the position of the robot 2 is corrected using the target point. This point will be described in detail below.

First, the robot 2 at the position shown in FIG. 1 is further advanced, and when the target point 1a is captured by the TV camera 5, the robot 2 is stopped. To remotely switch to the side view state. As a result, the image of the target point 1a captured by the TV camera 5 and displayed on the monitor TV 11 becomes substantially linear as shown in FIG. Therefore, if the relative distance between the target point 1a and the robot 2 is calculated and the distance on the design drawing of the target point 1a is added, the position of the robot 2 can be accurately corrected.

Hereinafter, the correction method will be described with reference to the flowchart of FIG.

First, in step S1 shown in FIG.
Is initially set to 0, the difference Δd between the actual running distance d ′ of the above and the calculated running distance d calculated based on the count value of the counter 7. Next, at step S2, the count value C ₀ of the counter 7 is taken into the arithmetic and control unit 8, and at step S3, d = δ · C ₀
The running distance d is calculated from + Δd. Here, δ is a movement amount corresponding to one step of the robot 2. Then, in step S4, the calculated traveling distance d is displayed on the monitor TV11.

In step S5, it is determined whether a distance correction command has been issued from the input device 9. If not, the process proceeds to step S6, and it is determined whether the inspection work has been completed. If the inspection work has been completed, the process proceeds to step S7 and ends. When it is determined that the inspection work is not completed, the process returns to step S2.

On the other hand, when it is determined in step S5 that there is a distance correction command, the flow shifts to the processing system in step S8. That is, when the operator watching the monitor TV 11 visually recognizes that the target point 1 a has been captured in the side view of the TV camera 5, the input device 9 inputs a distance correction command signal. In response to the input of the command signal, first, in-pipe image data including the target point 1a captured by the TV camera 5 is transferred to the image memory
Store in 13. At this time, the image displayed on the monitor TV 11 is image data divided into pixels of i in the horizontal direction and j in the vertical direction as shown in FIG.

Further, in response to the input of the correction command signal from the input device 9, the arithmetic and control unit 8 determines in step S8 that the center coordinates (i / 2, j /
2) is designated, and the data values of the vertical a pixel and the horizontal b pixel are stored in another memory (not shown) built in the arithmetic and control unit 8 with this point as a center (step S9). At this time, the coordinates of the pixels of the points A, B, C, and D forming the rectangular cursor 16 are as shown in FIG. 3 (a).
Is displayed as shown in FIG. 3A (step S1).
0).

Next, the cursor 16 is moved up and down by a command signal from the input device 9 in order to align the cursor 16 with the image of the target point 1a displayed on the screen of the monitor TV 11 (step S11). For example, when the cursor 16 is moved upward by one step, the cursor 16 is displayed as shown in FIG. 3B by subtracting the coordinates of the entire cursor by the amount of movement in the Y-axis direction. At this time, the coordinate data corresponding to A, B, C, and D stored in the separate memory is written again to the image memory 13, and instead, A ', shown in FIG.
Coordinate data corresponding to B ', C', D 'is stored in another memory.

Hereinafter, the cursor 16 can be moved upward or downward by sequentially repeating the above-described operation processing, and the cursor 16 can be adjusted to the target point 1a as shown in FIG.

In FIG. 4, the target point 1a projected on the monitor TV11
Image reflects the actual positional deviation of the robot 2 with respect to the target point 1a. In the case shown in the figure, the robot 2 is shifted upward from the center coordinates of the image memory 13, so that the robot 2 moves to the target point 1a. On the other hand, it is shifted from the center coordinates (reference position) of the cursor 16 shown in FIG. 3A by a distance corresponding to the distance from the target point 1a shown in FIG.

After aiming the cursor 16 at the target point 1a as shown in FIG. 4, the distance on the design drawing of the target point 1a in the pipe 1 is determined.
inputting a d ₀ from the input device 9 (step S12). Also,
Since the pixel size on the image memory 13 is uniquely determined if the tube diameter is uniform, the reference position of the cursor 16 shown in FIG. 3A and the cursor 16 on the target point 1a shown in FIG. The relative distance between the robot 2 and the target point 1a can be calculated from the number of pixels existing between the positions. That is, this relative distance is d ″
Then, the actual traveling distance of the robot 2 is d ′ = d ₀ +
d ", and this calculation is executed in step S13. Therefore, the calculated error Δd of the traveling distance d calculated based on the count value of the counter 7 becomes Δd = d'-d, which is executed in step S14. And returns to step S3.

Hereinafter, the corrected traveling distance can be obtained by adding the error Δd as a correction term to the traveling distance d calculated based on the count value of the counter 7. This distance d is displayed on the monitor TV 11 as shown in FIG.

Therefore, in the present embodiment, the travel distance of the robot 2 is corrected for each target point, so that the position of the robot 2 is accurate and the position of a defect in a pipe or the like can be accurately grasped. In particular, when inspecting the cracks in the welding part of the pipe mounting seat with an ultrasonic probe, after correcting the robot odometer based on the target point which is the welding line for pipe connection,
If the distance from the target point 1a to the seat weld is measured by the odometer based on the count value of the counter 7, welding cracks in the seat that cannot be seen from the inner surface of the pipe 1 can be reliably inspected with high positional accuracy. In this case, the ultrasonic probe is
It is preferable that the ultrasonic probe is mounted on a follower that is further connected after the above, and the relative distance between the TV camera 5 and the ultrasonic end probe is known. Can be measured.

In the configuration of the above embodiment, the robot 2 monitors the running body, the robot controller 6 controls the running body control device, the counter 7 and the arithmetic and control unit 8 monitor the commanded travel distance calculating means, the TV camera 5 monitors the photographing means, and The TV 11 constitutes a display means, and the arithmetic and control unit 8 constitutes a traveling distance correction means.

In the above embodiment, the calculated travel distance was corrected by adding the relative distance data and the designed travel distance data and calculating the deviation between the calculated distance data and the addition result. Even if the robot 2 is run for a distance and stopped, the calculated travel distance is calculated at that position, and the deviation between the calculated travel distance and the designed travel distance is calculated to correct the calculated travel distance. Good. TV camera 5
Although the inside of the tube was photographed with, the photographing may be performed with a two-dimensional camera such as a CCD. Further, the welding line of the pipe is set as the target point. However, the welding line is not particularly limited as long as the distance data is known in advance.

G. Effects of the Invention As described above, according to the present invention, a correction amount is calculated based on a known target point such as a welding line existing in a pipe, and the travel distance of the robot is calculated based on the correction amount. Is corrected, the existence point of the robot can be accurately detected, and accordingly, the position of a defect or the like on the inner and outer surfaces of the pipe can be accurately grasped.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of an in-pipe inspection apparatus according to the present invention, FIG. 2 is a flowchart showing an operation for correcting a traveling distance in the present embodiment, and FIG.
(B) is an explanatory diagram of a cursor in the present embodiment, FIG. 4 is an explanatory diagram showing a display example of a cursor and a target point displayed on a monitor TV, and FIG. 5 is a display example of a traveling distance displayed on a monitor TV. FIG. 1: Piping, 2: Robot 5: TV camera 6: Robot control device, 7: Counter 8: Operation control device, 9: Input device 10: Image input / output device, 11: Monitor TV 13: Image memory, 14: Camera control apparatus

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Akira Hashimoto 650, Kandamachi, Tsuchiura-shi, Ibaraki Pref. Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant (56) References JP-A-60-225580 (JP, A) JP-A-62-226786 (JP, A) JP-A-1-109089 (JP, A) JP-A-1-59856 (JP, A U) Japanese Utility Model Sho 64-54234 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 21/84-21/90 F17D 5/06 G03B 15/00

Claims (1)

(57) [Claims] 1. A traveling body traveling in a pipe, traveling body control means for controlling the forward / backward movement of the traveling body by a remote operation command, and calculating a calculated traveling distance of the traveling body based on the remote operation command. Travel distance calculating means, photographing means mounted on the traveling body for photographing a predetermined area in the pipe, display means for superimposing and displaying an image photographed by the photographing means and a cursor, and displaying the cursor. The relative distance between the traveling object and the target point is calculated based on the amount of movement of the cursor when the cursor is moved from the reference position to the target point in the pipe on the display screen, and a known distance to the previously input target point is calculated. An in-pipe inspection device, comprising: a traveling distance correction unit that corrects a calculated traveling distance of the traveling body from the distance data, the calculated relative distance data, and the calculated traveling distance data. .