JPH03208765A - Piping inside checking method using moving robot - Google Patents

Abstract

PURPOSE:To reduce the accumulative errors of a moving distance, by providing on a moving robot side an angle sensor detecting an angle which is made by perpendicular ity and its moving direction axis, and deciding that it is a crookedness point when its detected angle is within the range of a determined value, and regarding this crooked ness point as a reference point for the next movement. CONSTITUTION:At a moving robot R at which a preceding vehicle 1 provided with a sensor portion 1b such as a super sonic feeler at the front, and a following vehicle 2 are connected through a universal joint 3, and which moves like a measuring worm by combining the expanding/contracting movements of a preceding vehicle side cylinder 1c with the expanding/contracting movements of plural arms 1d, 2d provided at the preceding vehicle 1 and the following vehicle 2, a weight angle sensor 6 is provided within the preceding vehicle 1. And the output signal of this sensor 6 is inputted into a detection data processor 7, and the decision of whether or not a detected angle is within a predetermined angle range is made with a crookedness point/distance. Angle data table as a reference, and in the case of its being within the range, it is decided that the position of the robot R is at the crookedness point, and the movement amount of the moving robot R is calculated by making this crookedness point a refer ence point for the next movement.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an internal pipe inspection method using a mobile robot that inspects pipes from the inside. A robot travel distance calculation method that can reduce the error in the calculated robot travel distance in a piping inspection system that moves through sloped piping and uses ultrasonic measurement to detect internal defects based on the travel distance. Regarding.

[Prior Art] An example of a conventional mobile robot (hereinafter referred to as robot) for inspecting the inside of piping will be explained with reference to FIGS. 4 and 5.

1 includes a main body 1a provided inside the pipe 4 substantially along the axis of the pipe 4, and a main body 1a provided at the front part of the main body 1a.
A sensor part 1b having an ultrasonic probe, a camera, etc., a cylinder 1c extending and contracting in the axial direction of the pipe 4 provided at the rear of the main body 1a, and a plurality of cylinders extending and contracting from the main body 1a in a direction perpendicular to the axis of the pipe 4. The front vehicle consists of an arm 1d.

In this example, four arms 1d are provided at the front and rear parts of the main body 1a at equal pitches around the circumference. 2 is a rear vehicle connected to the front vehicle 1 via a universal joint 3; like the front vehicle 1, the main body 2a is provided approximately along the axis of the piping 4;
It is composed of a plurality of arms 2d that extend and contract from the main body 2a in a direction perpendicular to the axis of the pipe 4. R is a robot for inspecting the inside of piping, which consists of a front wheel 1, a universal joint 3, and a rear wheel 2.

Reference numeral 5 denotes a power supply and signal cable for the robot H, which is suspended from the lower end of the robot R. FIG. 5 shows the operation procedure for walking movement of the robot R in the pipe 4. When moving in the direction of the arrow shown in the figure, first, (
a) state, that is, arm 1d. Both arms 2d are extended until they press the inner circumferential surface 4a of the pipe 4, and from the state in which the robot R cannot move, the arm 1d of the front vehicle l is shortened, as shown in (b), and then the cylinder 1c is extended. (C
). Next, the arm 1d of the front vehicle 1 is extended and presses the inner circumferential surface 4a of the pipe 4 to make the front vehicle 1 unable to move (d), and the arm 2d of the rear vehicle 2 is shortened to the state (e). do. In the state of (e), shorten the cylinder 1c and (f
), and when the arm 2d is extended, it becomes the state (g), which is the same as (a) above, and returns to the state (a). By repeating the above operations, it is possible to move not only horizontal pipes but also vertical pipes. Note that movement in the opposite direction can be achieved by reversing the operations of the front vehicle 1 and the rear vehicle 2.

In this case, walking corresponds to one cycle of expansion and contraction of the cylinder, and if one step is considered to be one step, then
The moving distance is given by the number of steps x the amount of extension of the cylinder. Therefore, by giving a one-step signal or a cylinder expansion/contraction signal to the robot via the cable 5 and counting the number of times, the amount of movement (traveling distance) of the robot can be calculated.

[Problem to be solved] When this type of piping inspection robot R moves inside the piping, the amount of expansion and contraction of the cylinder and the walking distance may be affected due to movement errors due to the influence of scales, slippage, cylinder expansion and contraction errors, etc. The two do not correspond and shift, and the shift accumulates. In particular, when the robot climbs or descends a vertical pipe or a steeply inclined pipe, the accumulated errors become large, and the errors become more compounded as the distance the robot moves becomes longer. Therefore, there is a drawback that the actual location of the defect and the measured location cannot be sufficiently matched, and accurate measurement data cannot be obtained.

This invention solves the problems of the prior art, and uses a mobile robot that can reduce the cumulative error in the robot's travel distance and obtain data close to the actual travel distance. The purpose is to provide a piping internal inspection method.

[Means for Solving the Problems] The structure of the internal pipe inspection method using the mobile robot of the present invention to achieve such an objective is to provide the mobile robot with an angle between the axis of its movement direction and the vertical. An angle sensor for detection is provided, and an inspection data processing device stores the judgment value of the detected angle of the angle sensor detected at the bending point at the bending point in the pipe, and the inspection data processing device stores the judgment value of the detected angle of the angle sensor detected at the bending point, and detects the angle sensor sent from the mobile robot. When the angle is within a range of determination values, it is determined that it is a turning point, and the amount of movement of the mobile robot is calculated using this turning point as a reference point for the next movement.

[Function] In this way, since the mobile robot side is provided with an angle sensor that detects the angle between the axis of the movement direction and the vertical,
The position of the bending point -6- can be detected by the detection angle of this angle sensor, and if the position of the bending point of the pipe is detected and the subsequent travel distance is calculated using that as a reference point, and this is done for each bending point, The error stops accumulating from one bending point to the next bending point, and no longer accumulates.

In addition, if you calculate the travel distance using the actual distance to the bending point based on the actual distance of the piping, the distance from the start point of travel can be obtained more accurately, so the position data of defects etc. can be more accurate. Therefore, highly accurate inspection data can be obtained.

[Example] An example of the present invention will be described below using drawing F1.

FIG. 1 is a block diagram of a piping inspection system using a walking robot to which the piping internal inspection method using a mobile robot of the present invention is applied, and FIG. 2 is an explanatory diagram of the bending point/distance ● angle data table, FIG. 3 is a piping route diagram showing an example of the piping. Components that are the same as those in FIG. 4 are indicated by the same reference numerals, and their explanation will be omitted.

In FIG. 1, a weight angle sensor 6 is built into a front vehicle 1 of a robot R as shown by a dotted line.

This weight angle sensor 6 has a sensor section that supports a weight part located in the gravity direction, rotatably supports this in a plane perpendicular to the central axis of the robot R, and detects the angle between the axis and the weight. and an angle detection mechanism part having a potentiometer.

7 is an inspection data processing device in which a microprocessor 71, an interface 72, a memory 73, an ultrasonic flaw detector 74, a display, a magnetic disk storage device (not shown), etc. are interconnected via a bus 75. The memory 73 stores an ultrasonic inspection program 73.
a1 Robot walking control program 73b1 Movement amount calculation program 73c1 Angle determination program 73d1 Turning point/
A distance/angle data table 73e and the like are stored.

Here, the robot walking control program 73b is activated when image collection for defect measurement is completed, and generates a signal to extend and retract the cylinder 1c to make the robot R walk one step next. Control the robot to walk one step. Along with this control, this program updates the number of walking steps N as a variable stored in the parameter area of the memory 73 by 1 in accordance with the one-step walking described above. Then, the angle determination program 73d is started.

The angle determination program 73d is started by the robot walking control program 73b, and calculates the angle e obtained from the weight angle sensor 6 sent from the robot R to each bending point Pi - ps t of the bending point/rejection angle data table 73d.
Judgment angle θL 1 -e L provided for ●●●
5 + ●●● (lower limit value of angle) ~e■1~eHsw
Based on ●●● (upper limit value of the angle), refer to the corresponding judgment angle values sequentially such as P1 + next P2 as the first breakthrough point, and compare them with the angle obtained from the angle sensor 6. It is determined whether the current angle obtained from the angle sensor 6 is within the range of each angle range θt-on, and when it is within that range, the current position of the robot R is determined. It is determined that this is the passing point of that bending point. When it is determined that this is the passing point, the number N of walking steps stored in the memory 73 is cleared to zero.

As a result, the previous number of walking steps N is reset at the bending points P1 to Psv ●●● of the piping shown in Fig. 3, and the walking steps within the section are changed according to the sections divided by these points. It will be shown. Note that this program starts the movement amount calculation program 73c at the time when the determination process is completed.

The movement amount calculation program 73c is the angle determination program 7
3d, the number of walking steps N is read out from the memory, and the turning point/distance angle data table 73 is read out.
Each bending point Pl-P5 of d, actual measurement data Nll-M from the actual piping start point O (origin) to the bending point of ●●●
s + ●●● (see FIG. 3), the moving distance data mi from the current starting point 0 at the moving position after the bending point P2 is calculated by mi = MI-t + NX (one step moving amount). However, i corresponds to the number -10 of each bending point, ml means the distance from the start point in the section beyond the bending point, and N is the section updated by the robot walking control program 73b. is the number of steps in . Note that the distance of the section from the start point O before the turning point P2 to the turning point PI is calculated as ml''N×(one-step movement amount) by substituting M=0 into the previous equation.

When this program calculates the moving distance, it stores it in a predetermined area of the memory 73 and starts the ultrasonic inspection program 73a.

The ultrasonic inspection program 73a examines the state around the pipe 4 using ultrasonic waves corresponding to the number of walking steps N corresponding to the section divided by bending points P1 to P5 + ●●● of the pipe shown in FIG. For example, by collecting a C-scope image of the surrounding area and developing it into image data, the number of walking steps N in that section and the section (for example, managed by a turning point PI, and from the turning point Pi to the next turning The image data collected according to the identification code representing the interval up to the point PI+t is stored in the memo U 7 3 and displayed on the display. Then, the image data in the memory 73 is identified by its step number and section, and is transferred to and stored in the magnetic disk storage device along with distance information calculated in accordance with the identification code. As a result, the distance and screen data can be read and reproduced later using this identification code.

By the way, regarding the processing procedure for such inspections,
Here, the program will be started and executed as explained above, so its explanation will be omitted.

In this way, each section is divided and the distance is calculated based on the previous bending point, so the actual amount of movement of the robot is based on the distance measured for each bending point. Converted and calculated. As a result, the accumulated errors remain within each section, and those from other sections do not accumulate and intrude.

By the way, in this embodiment, the judgment angle is collected in the third correspondence, but if this is measured as a horizontal inclination angle, the angle obtained from the weight angle sensor 6 is the horizontal direction. It is necessary to convert the angle, or convert the judgment value side to the angle measured from the vertical, and then compare the two.

In addition, these compared angles are originally only used to determine whether or not there is a bending point, so even if solid angles are not used,
It can be determined if there is a certain angle in a certain direction. So, for example, if the piping is X - Y Sl' if
ii, and collect it as its inclination angle, and use the angle sensor 6.
It is also sufficient to detect the detected angle as the projection angle component of the XY plane and compare the ranges thereof.

As explained above, in the example, the distance from the start 0 is calculated using the actual measured data, but this is done by simply calculating the distance for each section without adding the actual measured data. It may be possible to manage measurement data such as image data and process the data.

In the embodiment, the bending points are determined in order, but if each bending point does not have the same judgment value, the judgment may be made in any order, and the judgment values are sequentially compared. It may also be possible to determine which bending point it is. In this case, 2
If two or more of the same determination ranges overlap, one of them may be determined using other parameters.

[Effects of the Invention] As explained above, in this invention, since the mobile robot side is provided with an angle sensor that detects the angle between the axis of the movement direction and the vertical, the detection angle of this angle sensor is The position of the bending point can be detected by detecting the position of the bending point of the pipe, and calculating the subsequent travel distance using it as a reference point. If this is done for each bending point, the next bending point from the bending point with an error can be detected. Accumulation stops at the bending point, and E is no longer accumulated after that point.

In addition, if the moving distance is calculated using the actual distance to the bending point based on the actual distance of the piping, the distance from the starting point of movement can be obtained more accurately, and the position data of defects etc. will be more accurate. , it is possible to obtain highly accurate inspection data.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a pipe inspection system using a walking robot to which the pipe internal inspection method using a mobile robot of the present invention is applied, and Fig. 2 shows its bending point/distance.
An explanatory diagram of the angle data table, FIG. 3 is a piping route diagram showing an example of the piping, FIG. 4 is a diagram showing an example of a conventional robot for inspecting inside piping, and FIG. 5 is the robot shown in FIG. 4. FIG. 3 is a diagram showing an operation procedure for moving the inside of the pipe. 1... Front car, 2... Rear car, 3... Universal joint, 4...
... Piping, 5... Cable, 6... Weight angle sensor, 7... Inspection data processing device, 7l... Microprocessor, 72... Interface, 73... Memory, 74... Display, 75...
・Magnetic disk storage device, 76... Ultrasonic flaw detection section, 77... Bus, 73a...
・Ultrasonic inspection program, 73b...Robot walking control program, 73c...
- Travel amount calculation program, 73d... Angle judgment program 73, 73e... Turning point/distance●Angle data table. -15-Figure 2 JP-A-3-208765 (6) Figure 4

Claims (3)

[Claims] (1) A mobile robot for inspecting the inside of the piping, which has a sensor such as an ultrasonic probe for inspecting the condition inside the piping, and which moves inside the piping and sends out inspection results regarding the condition inside the piping; In a piping inspection system comprising an inspection data processing device that receives inspection results, the mobile robot has an angle sensor that detects an angle between an axis in the moving direction of the robot and the vertical, and the inspection data processing device A judgment value of the detection angle of the angle sensor detected at the bending point is stored, and when the detection angle of the angle sensor sent from the mobile robot is within the range of the judgment value, the turning point is detected. A piping internal inspection method using a mobile robot, characterized in that the movement amount of the mobile robot is calculated using the bending point as a reference point for the next movement. (2) Piping using a mobile robot according to claim 1, wherein the calculated travel amount of the mobile robot is calculated as a travel distance from a travel start point based on the actual distance of the pipe to the bending point. Internal inspection method. (3) The judgment value is the inclination angle of the bending point when the pipe is projected onto a specific plane, and either one of the detection angle of the angle sensor sent out from the mobile robot and the judgment value is the angle measurement condition of the other. 3. The internal pipe inspection method using a mobile robot according to claim 1 or 2, wherein the detected angle is converted into the determined value and the determined value is compared.