DE102017110007A1 - Method and apparatus for determining a distance - Google Patents

Abstract

Disclosed is first a method for determining a distance (14) between a starting point (18) and an end point (21) on an inner wall (5) of a tubular channel (1), wherein by means of a camera an image (16) of the wall ( 5), and first the starting point (18) and the end point (21) in the image, and then the distance (14) is determined. Also disclosed is a device (2) for determining a distance (14) between a starting point (18) and an end point (21) on an inner wall (5) of a tubular channel (1), having an inspection device (11) which has a Camera and a pivot drive for the camera, and with a control device (11) connected to the control means by which the inspection device (11) in the channel (1) from outside the channel (1) is controllable. To improve the measurement is proposed in that in a starting direction (19) a starting distance (20) of a distance measuring device from the starting point (18) and in an end direction (23) pivoted about a pivoting angle (22) to the starting direction (19) is an end distance (24) of the distance measuring device from the end point (21), and the distance (14) from at least the starting distance (20), the final distance (24) and the swivel angle (22) is determined trigonometrically.

Description

The invention relates firstly to a method for determining a distance between a starting point and an end point on an inner wall of a tubular channel, wherein an image of the wall is generated by means of a camera, and first the starting point and the end point in the image, and then determines the distance becomes. The invention further relates to a device for determining a distance between a starting point and an end point on an inner wall of a tubular channel, with an inspection device which has a camera and a pivot drive for the camera, and with a controller connected to the inspection device by means of which Inspection device in the channel from outside the channel is controllable.

Methods and devices of the aforementioned type are used to measure an object on the wall, such as a crack in the wall or the inlet of a pipe connected to the channel.

DE 43 13 104 A1 Proposes to direct two lasers parallel to the lens direction of the camera on the object and to determine the size of the object by comparison with the known distance of the laser spots in the image. The known method does not allow direct measurement of the object. The camera must be directed perpendicular to the wall to avoid false measurements due to parallax. Furthermore, the length determined on the object must lie in the longitudinal direction of the channel in order to avoid an erroneous measurement by the spherical curvature of the channel.

In the background of the invention proposes DE 20 2013 100 437 U1 to provide the inspection device with an infrared distance measurement and to successively center the inspection device in the channel by performing two distance measurements in opposite directions to the channel wall and moving the inspection device in the direction of the greater distance.

In the background of the invention suggests further DE 20 2016 000 435 U1 to provide the inspection device with a laser source and a plurality of line sensors and to rotate during the process of the channel robot about an axis parallel to the channel, so that the wall is scanned helically.

Furthermore, in the background of the invention so-called. Tachymeter with laser distance meters and fine adjustment or automatic adjustment of pivoting angles are generally known, which are used for geodetic surveying of points.

task

The invention has for its object to improve the measurement of the distance.

solution

Starting from the known method is proposed according to the invention that in a starting direction a starting distance of a distance measuring device from the starting point and in a direction of rotation pivoted by a pivot angle end direction measured a final distance of the distance measuring device from the end point, and the distance from at least the starting distance, the End distance and the pivot angle is determined trigonometrically. The method according to the invention known from geodesy allows the free choice of start and end point on the wall and thus the direct measurement instead of the comparison with another, known distance.

By measuring the distances in other points in the immediate vicinity of the object, the local curvature of the wall can also be determined and determined by spherical trigonometry, the arc length of the running through the start and end point on the wall line.

Preferably, in a method according to the invention, the distance measuring device has a distance sensor which first measures the starting distance, then pivots about the pivot angle and then measures the end distance. The method according to the invention thus requires only a single distance sensor.

Preferably, in such a method according to the invention, the distance sensor always aims parallel to the camera on the wall. The method according to the invention thus avoids a separate adjusting device for the distance sensor.

Alternatively, in a method according to the invention, the distance measuring device preferably has a first distance sensor, which measures the starting distance, and a second distance sensor, which pivots the final distance by the pivoting angle to the first distance sensor. The inventive method thus enables the simultaneous measurement of start and end distance.

Preferably, in a method according to the invention, the distance measuring device measures a transit time of a signal emitted by the distance measuring device, which is reflected by a point of the wall, to which the Distance measuring device aims. The signal may be a light beam, in particular an infrared laser beam. Highly integrated distance measuring elements with infrared laser and infrared-sensitive photocell are well known in miniaturized form. Alternatively, the signal may in particular be an ultrasonic or radar signal.

Preferably, in such a method according to the invention, the signal is not visible and a visible light marking laser aims at the wall parallel to the distance measuring device. The method according to the invention thus combines the advantages of the measurement with non-visible signals with the visibility of the measuring point in the image of the wall taken with the camera.

Starting from the known device is proposed according to the invention that the inspection device comprises a distance measuring device and the control device is adapted to store a measured in a starting direction starting distance from the distance measuring device to the starting point, a pivot angle and one of the distance measuring device in a direction to the starting direction around the Pivoting angles pivoted end direction of the measured end distance from the distance measuring device to the end point, as well as to determine the distance from at least the starting distance, the end distance and the pivot angle trigonometrically. The inventive device enables the execution of the method according to the invention and is characterized equally by the advantages listed above.

Preferably, in a device according to the invention, the control device is set up to reproduce an image of the wall recorded by the camera on a display element. The device according to the invention thus simplifies the optical control.

Preferably, in such a device according to the invention, the control device is set up to reproduce on the display element a scale which corresponds to the distance. The scale displayed on the rendering element further simplifies visual control.

Preferably, a device according to the invention comprises a manipulator for internal testing and / or machining of the channel, wheels for driving on the inner wall, and at least one motor for the wheels, and by a line to the control device, by means of which the wheels can be supplied with drive energy , Such a channel robot simplifies the machining preparatory, accompanying or inspecting optical inspection of the channel.

Alternatively, a device according to the invention is a well camera for internal testing of a shaft structure with a substantially perpendicular longitudinal axis. Such a fountain camera simplifies the optical inspection of the shaft structure, in particular the measurement of the width of vertical inlet slots.

list of figures

• 1 eine erfindungsgemäße Vorrichtung in einem Kanal und
• 2 ein Wiedergabeelement mit einem Abbild der Wandung.

The invention will be explained below with reference to an embodiment. Show it

• 1 a device according to the invention in a channel and
• 2 a display element with an image of the wall.

In the 1 in a canal 1 shown device according to the invention 2 has a manipulator 3 up, four wheels 4 to drive on an inner wall 5 of the canal 1 , a motor, not shown, for the wheels 4 and a line 6 to a likewise not shown control device outside the channel 1 ,

The manipulator 3 has one about the longitudinal axis 7 the device 2 swivel foot 8th , and one on the foot 8th from the longitudinal axis 7 swiveling arm 9 on. At the free end 10 of the arm 9 is an inspection device 11 pivotally mounted. The engine, the manipulator 3 and the inspection device 11 be over the line 6 controlled by the control device and supplied with electrical drive power.

The inspection device 11 has a camera and a rotary actuator for the camera, as well as a distance measuring device. The distance measuring device consists of a single distance sensor, always parallel to the camera - here: on the wall 5 of the canal 1 - aims and an immediately adjacent and also parallel aligned marking laser. The distance sensor is a highly compact infrared laser sensor with a wavelength of 940 nm and a measuring range of up to 2 m distance. The distance sensor and the other elements of the inspection device 11 are not shown individually.

To the canal 1 is at an enema 12 a pipe 13 connected. To the distance 14 between opposite edges 15 of the enema 12 To determine, the camera is first on the enema 12 directed. The control software installed in the control device for the device according to the invention 2 gives the image taken by the camera 16 the wall 5 as in 2 shown on a display element 17 used flat screen again.

At the beginning of the measurement, the control software evaluates the light-dark gradients in the image 16 out, determines a proposal for a starting point 18 slightly outside the edge of the enema 12 and turns the camera in a starting direction 19 in which the distance sensor and the marking laser are at this starting point 18 aim. After correction and confirmation of the starting point if necessary 19 by the operator on the control device, the control software stores the value measured therefrom by the distance sensor as a starting distance 20 ,

Then, the control software similarly determines a suggestion for an opposite endpoint 21 and swivels the camera around a swivel angle 22 in an end direction 23 in which the distance sensor and the marker laser on this end point 21 aim. Again, if necessary, correction and confirmation of the endpoint 21 by the operator, the control software stores the value measured there by the distance sensor as the end distance 24 and determines trigonometrically from starting distance 20 , End clearance 24 and tilt angle 22 the distance 14 between starting point 18 and endpoint 21 ,

In the picture 16 hides the control software markings 25 for the starting point 18 and the endpoint 21 a, as well as a scale 26 whose length 27 the calculated distance 14 between starting point 18 and endpoint 21 equivalent. By moving and pivoting this scale 26 in the image 16 The operator intuitively gets an idea of the conditions in the channel 1 and, if necessary, trigger further measurements.

LIST OF REFERENCE NUMBERS

1

channel

2

contraption

3

manipulator

4

wheel

5

wall

6

management

7

longitudinal axis

8th

foot

9

poor

10

The End

11

inspection device

12

enema

13

pipe

14

distance

15

edge

16

image

17

Display element

18

starting point

19

start direction

20

start distance

21

endpoint

22

swivel angle

23

end direction

24

end distance

25

mark

26

scale

27

length

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4313104 A1 [0003]
• DE 202013100437 U1 [0004]
• DE 202016000435 U1 [0005]

Claims (10)

Method for determining a distance (14) between a starting point (18) and an end point (21) on an inner wall (5) of a tubular channel (1), wherein an image (16) of the wall (5) is produced by means of a camera, and first the starting point (18) and the end point (21) in the image (16), and then the distance (14) is determined, characterized in that in a starting direction (19) a starting distance (20) of a distance measuring device from the starting point (18) and in an end direction (23) pivoted about a pivoting angle (22) to the starting direction (19), an end distance (24) of the distance measuring device is measured from the end point (21), and the distance (14) from at least the starting distance (20). , the end distance (24) and the swivel angle (22) is determined trigonometrically. Method according to the preceding claim, characterized in that the distance measuring device has a distance sensor which first measures the starting distance (20), is then pivoted about the swivel angle (22) and then measures the final distance (24). Method according to the preceding claim, characterized in that the distance sensor always aims parallel to the camera on the wall (5). Method according to Claim 1 characterized in that the distance measuring means comprises a first distance sensor measuring the start distance (20) and a second distance sensor pivoted about the pivot angle (22) to the first distance sensor and measuring the end distance (24). Method according to one of the preceding claims, characterized in that the distance measuring device measures a transit time of a signal emitted by the distance measuring device, which is reflected from a point of the wall (5), which is aimed at the distance measuring device. Method according to the preceding claim, characterized in that the signal is not visible and a marking laser with visible light parallel to the distance measuring device on the wall (5) aims. Device (2) for determining a distance (14) between a starting point (18) and an end point (21) on an inner wall (5) of a tubular channel (1), with an inspection device (11) comprising a camera and a pivot drive for the camera, and with a control device connected to the inspection device (11) by means of which the inspection device (11) in the channel (1) is controllable from outside the channel (1), characterized in that the inspection device (11) is a distance measuring device and the control device is set up to store a starting distance (20) measured in a starting direction (19) from the distance measuring device to the starting point (18), a swivel angle (22) and from the distance measuring device in a direction of rotation (19) about the swivel angle (22) pivoted end direction (23) measured final distance (24) from the distance measuring device to the end point (21), and the distance (14) a us at least the starting distance (20), the end distance (24) and the pivot angle (22) to determine trigonometrically. Device (2) according to the preceding claim, characterized in that the control device is set up to reproduce an image (16) of the wall (5) taken by the camera on a display element (17). Device (2) according to the preceding claim, characterized in that the control device is arranged to reproduce on the display element (17) a scale 26 which corresponds to the distance (14). Device (2) according to one of Claims 7 to 9 characterized by a manipulator (3) for internal testing and / or machining of the channel (1), wheels (4) for driving on the inner wall (5), and at least one motor for the wheels (4), and by a Line (6) to the control device, by which the wheels (4) are supplied with drive energy.

Images