DE102012023400A1 - Channel detection system of inertial navigation system for use in e.g. flight navigation, has inertial sensors that detect multi-dimensional measurement signal corresponding to current location of sewer pipe during movement - Google Patents

Abstract

The system has multiple measuring probes (2-4) that comprises multiple inertial sensors (5-7) and are arranged horizontally in a row on a measuring head (1). Each inertial sensor is adapted to detect a multi-dimensional measurement signal (X-Z) corresponding to the current location of a sewer pipe during movement. One of the inertial sensors are aligned to one direction in space of the measuring probes of the measuring head, and other inertial sensor is installed at different angular position in a direction deviating from a spatial direction of the measuring probe.

Description

The invention relates to a channel location system with paired inertial sensors according to the preamble of claim 1.

Inertial sensors are used to measure accelerations and yaw rates. They enable the acquisition of sometimes complex and multi-axis motion operations with up to six degrees of freedom. The combination of different inertial sensors is referred to in microsystem technology as inertial measuring units.

An inertial measuring unit is the main component of an inertial navigation system. Are used inertial measuring units u. a. in flight navigation, robotics and image stabilization for motion detection.

In many cases, the interaction of several inertial sensors shows the strengths of this technology in the application.

Inertial measuring units are used to precisely detect rotational movements, accelerations and inclinations in space. Due to the small size of the signals occurring in the sensor are usually very small and require a data processing as an interface for further processing.

• • Drei orthogonal angeordnete Beschleunigungssensoren (auch als Translationssensoren bezeichnet) detektieren die lineare Beschleunigung in x- bzw. y- bzw. z-Achse. Daraus kann die translatorische Bewegung berechnet werden.
• • Drei orthogonal angeordnete Drehratensensoren (auch als Gyroskopische Sensoren bezeichnet) messen die Winkelgeschwindigkeit um die x- bzw. y- bzw. z-Achse. Daraus kann die Rotationsbewegung berechnet werden.

Inertial measurement units typically include the following types of sensors:

• • Three orthogonally arranged acceleration sensors (also referred to as translation sensors) detect the linear acceleration in the x, y and z axes. From this, the translational motion can be calculated.
• • Three orthogonal yaw rate sensors (also known as gyroscopic sensors) measure angular velocity about the x, y, and z axes, respectively. From this, the rotational movement can be calculated.

With the going back to the same applicant DE 10 2006 036 416 A1 For example, a channel location system with position detection sensors is known, in which a number of translation sensors are arranged one behind the other on a measuring string, and this measuring string is introduced into a sewer pipe, after which the measurement takes place. Each of the measuring sensors arranged at a spatial distance one behind the other sensors generates a three-dimensional measurement signal - corresponding to the three spatial axes X, Y, Z - and the measurement signal of all spaced apart measuring sensors is used for the evaluation.

Due to the large number of measuring sensors arranged on a measuring strand, there is the advantage that the measuring deviation of a single sensor is compensated and compensated later in the evaluation by the measurement result of the subsequently arranged measuring sensor, so that the averaging and the counterbalancing of the measuring signals of all the trailing ones arranged lying Measuring sensors can be made a relatively accurate measurement result with respect to the position detection of this Meßstranges in the sewer pipe.

Disadvantage of this known arrangement, however, is that they are uniform measuring sensors, that is, each measuring sensor has only a single measurement characteristic and generates a single in the X, Y and Z direction directed measurement signal. Thus, a three-dimensional space coordinate is generated per unit of time by each measuring sensor.

However, this arrangement does not address a drift associated with the position detection sensors. In fact, it has been found that each of the layer detection sensors arranged one behind the other in the measuring chain has a considerable drift, which means that the counterbalancing of the spatial coordinates of successive layer detection sensors is not accurate enough.

In the case of approximately identical position detection sensors, which are of the same type and which are mounted in the same spatial orientation on the measuring strand, unwanted drift in a certain direction is given, which can not be eliminated by mutual compensation of the measurement results of the various position detection sensors.

The invention is therefore based on the object, a channel positioning system with position detection sensors and a plurality of spatially successively arranged position detection sensors, which result in a longitudinal directional measuring head to improve their accuracy.

To solve the problem, the innovation is characterized by the technical teaching of claim 1.

An essential feature of the invention is that the measuring head in a conventional manner consists of at least two consecutively arranged in spaced-apart measuring probes, and that the measuring head according to the invention is characterized in that in each probe at least three aligned in each direction of space inertial sensors are arranged , and that in one probe, the inertial sensors are aligned in a first spatial direction, while in the second, they are aligned subsequent measuring probe, the inertial sensors are installed in a deviating from the first spatial direction of the inertial sensors of the first probe angular position.

Thus, a measuring head is provided whose position detection sensors are arranged at a spatial distance from each other, and wherein the inertial sensors are arranged offset in each measuring head to each other, and the offset is present in a known solid angle.

The inertial sensor according to the invention has an integrated 3D magnetometer (3D compass), with a micro-processor and is able to perform a calculation of rolling, pitching and yawing movements in real time, as well as to output calibrated linear acceleration, Rate of rotation and Earth magnetic field data in 3D.

For ease of description, in the following description, it is assumed that the inertial sensors in the first measuring probe are located at exactly 90 degrees to the inertial sensors in the second measuring probe. However, the invention is not limited to such an angle of 90 degrees.

The invention may also provide that instead of an offset angle of 90 degrees an angle of 60 degrees or 120 degrees is provided. It is therefore crucial that the same inertial sensors are arranged in the one measuring probe as in the other measuring probe, and that at least three inertial sensors are arranged in each measuring probe, which, taken separately, are likewise aligned in each case in a spatial plane X, Y, Z.

Therefore, in contrast to the prior art, an assembly of three spatially offset inertial sensors is proposed in total, and it is additionally proposed that in two spatially spaced measuring sensors, the first arrangement of the spatially arranged inertial sensors to those in the second measuring probe spatially arranged inertial sensors forms a specific and known offset angle.

Thus, for example, the first measuring probe with at least three inertial sensors in one feed or spatial axis direction is particularly sensitive and has little drift, while the adjoining measuring probe with the inertial sensors, which have an angular offset from the first-mentioned inertial sensors, in another spatial axis of space Drift and in another spatial axis provides a particularly precise measurement result.

By pairing the measurement results of the at least three inertial sensors of the first measuring probe with the measurement results of the at least three inertial sensors in the second measuring probe, a highly accurate measurement result is achieved because only the corrected measuring curve consisting of the three inertial sensors of the first measuring probe and of the three inertial sensors of the first second measuring probe, is used for a corrected curve.

By calculation, therefore, a corrected curve is generated from the respectively at least three inertial sensors, obtained spatial coordinates of the first and the second probe, which then finally forms a highly accurate space curve, which is free of offset and an undesirable drift.

In the foregoing, only the pairing of two probes oriented spatially in the feed direction and having at least three inertial sensors in each probe are described.

However, the invention is not limited thereto. The invention may be provided in a development that a total of three spatially spaced apart measuring probes are provided, each probe in each case at least three inertial sensors are arranged offset in their spatial orientation to the arranged in the other probe, at least three existing inertial sensors to each other ,

The spatial spacing of the at least two probes in a measuring head, which is pushed or pulled along its longitudinal extent either in a pipeline, has the advantage that due to the spatial offset due to the spacing of the two probes in the longitudinal direction (displacement direction) also from the measurement result of the measuring head the curvature of the sewer pipe can be calculated.

If this additional feature is dispensed with, it is also possible to dispense with the spatial spacing of a plurality of measuring probes in a measuring head. It would then be possible to concentrate such probes in the form of a ball arrangement on a specific measuring head, which is, for example, spherical, so that it is also possible to dispense with the spatial spacing of a plurality of measuring probes, if the detection of the radius of curvature of a sewer pipe is dispensed with.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

All information and features disclosed in the documents, including the abstract, in particular the spatial design shown in the drawings, are claimed to be essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Show it:

1 shows: first embodiment of a measuring head with spaced measuring probes

2 shows: a second embodiment of a measuring head compared to 1

3 shows: a third embodiment of a measuring head

4 shows: the spatial measuring curves of the individual inertial sensors in the measuring probe 2 when moving in space

5 shows: spatial measuring curves of the at least three inertial sensors in the measuring probe 3 when moving in space

6 shows: the formation of a correction curve from selected measuring curves of the inertial sensors of the measuring probes 2 and 3

7 shows schematically the representation of the detection of the curvature of a pipe and its orientation in space in a first motion picture

8th shows: the same representation as 7 in a second movement picture

9 shows: the representation after 8th in a third movement picture

10 shows: the spatial representation of the corrected measuring curves of the measuring probes 2 and 3 when passing through a pipe bend

11 shows: schematic representation of the position of the measuring head when pulling through a sewer pipe in comparison to pushing through a sewer pipe

The 1 to 3 show the same measuring setup of a measuring head 1 consisting of at least two measuring probes arranged one behind the other 2 . 3 consists. The two probes 2 . 3 are through a link 8th spatially separated.

In the general description has already been noted that the link 8th can also be omitted, and that then but the detection of the curvature according to the 7 to 9 is no longer possible. However, a highly accurate location measurement of this measuring head 1 in the course of the pipeline after the 7 and 9 possible and provided.

So if in the following drawings a spatial connection via the link 8th at the measuring probes 2 . 3 and at the 3 over the connecting link 9 at the measuring probes 2 . 3 . 4 is not meant to be limiting.

Important in the invention is that in each probe 3 aligned inertial sensors in different spatial directions 5 . 6 . 7 are arranged. Later, the inertial sensors are also shown with the lowercase letters a, b and c in the drawings. It is important that in the probe 2 for example, the inertial sensor 5 aligned in the vertical direction while the same inertial sensor 5 in the probe 3 aligned in the horizontal direction. So he points in the probe 2 in the Z direction and is oriented in the Z direction, while the same inertial sensor 5 with the same electrical properties and the same drift and the same electrical output values in the probe 3 aligned in the Y direction.

The same applies to the inertial sensor 6 in the probe 2 aligned in the X direction while the same inertial sensor 6 in the probe 3 aligned in the Y direction. This applies analogously to the inertial sensor 7 in the probe 2 to 1 aligned in the Y direction while the same inertial sensor 7 in the probe 3 aligned in the Z direction.

Similar representations result from the 2 , where the orientation of the inertial sensors 5 - 7 in the respective measuring probes 2 . 3 is symbolized by an upright or flachkantstehendes box.

The result of the inventive idea of the invention is the pairing of measuring probes 2 . 3 . 4 with inertial sensors 5 . 6 . 7 , which differ from one probe to the other by a certain solid angle, but the same inertial sensors 5 . 7 with the same electrical properties in each probe 2 . 3 . 4 were installed.

The deviating solid angle between the inertial sensors 5 . 6 . 7 in the probes 2 . 3 is for example a solid angle of 90 degrees. The invention is not limited thereto. It has been pointed out in the general description that this solid angle can also assume other angles. So it only comes down to a spatial offset between the individual, identical trained inertial sensors 5 . 6 . 7 in the separate measuring probes 2 . 3 . 4 at.

All measuring sensors 2 . 3 . 4 are on a supply line 10 connected and pass on their measurement data.

The 1 also shows that the entire measuring head 1 either in the direction of the arrow 11 through a sewer pipe 20 (please refer 7 - 9 ) can be pushed, or he can in the direction of arrow 12 through the sewer pipe 20 to be pulled.

The differences that arise in the pulling or pushing operation, will later be based on the 11 explained.

It is important that the measurement results of the inertial sensors 5 - 7 in the individual measuring sensors and calculated to a corrected measuring curve 19 be summarized.

In 4 are for example the spatial measuring curves 13 . 14 . 15 the inertial sensors a, b and c of the measuring probe 2 shown. Here it can be seen that the measured curves 13 . 14 are spread only slightly apart, but essentially have no drift. Incidentally, the measured curves result from a spatial displacement of the measuring probe 2 . 3 along the arrow direction 11 or 12 ,

As the 4 shows, is the trace 15 of the inertial sensor a in the measuring probe 2 unfavorable because it leads to a drift in a spatial displacement and a false signal, which would lead to a faulty evaluation of the entire signal.

In 5 is a spatial movement curve based on measurement curves 16 . 17 . 18 inertial sensors a, b and c in the measuring probe 3 shown. Here is shown that the measured curves 16 . 17 The inertial sensors a3 and b3 differ from each other only by a slight spread, but that the measurement curve 18 from the inertial sensor c3 has an undesirable drift.

By a calculation method, not shown in detail according to 6 only the traces 14 . 16 . 17 from the inertial sensors of the measuring probes 2 . 3 selected and lead to the curves a3, c2 and b3, which only have a slight spread.

By mathematical averaging or weighting from these three measurement results a3, c2 and b3 is now the corrected waveform 19 generates a highly accurate locating curve of the measuring head 1 represents.

Thus, the inventive idea of the invention is described, namely that of the differently paired measuring probes 2 . 3 . 4 a measuring head 1 a corrected trace 19 is achieved, which is a highly accurate position signal of the measuring head 1 in the sewer pipe 20 generated.

In the 7 to 10 is shown that due to the spatial offset of the probes 2 - 3 - 4 through the links 8th and or 9 additionally also the curvature in the sewer pipe 20 can be detected.

In the moving picture after 7 it is assumed that the measuring head 1 in the direction of the arrow 11 through the sewer pipe 20 is pushed up, and this in a first pipe bend 21 arrives.

While the rear measuring head 2 still on the straight wall of the sewer pipe 20 is located, kinks the front probe 3 around the elastic or articulated connecting member 8th already around the pipe bend 21 Accordingly, and therefore provides a different waveform than the comparator of the probe 2 that is still on the flat surface.

This is in 10 shown.

The 10 shows the lower part of the corrected trace 19 the measuring probe 3 , Here it can be seen that these previously in the tube bend 21 einfährt as comparatively after calculation of the trace 19 the measuring probe 2 , Between the radii of curvature, which are the two probes 2 . 3 Measure in the pipe bend, so there is an offset line 28 ,

The distance 24 between the two corrected measuring curves depends on the length of the respective connecting link 8th . 9 and the actual radius of curvature of the pipe bend 22 . 23 ,

In this way, by the spatial offset of the two measuring curves 19 (2) 19 (3) highly accurate in the space the pipe bend of a sewer pipe 20 be found without it - as in the prior art - relies on an angle measurement in the region of the link 8th . 9 between measuring sensors 2 . 3 . 4 make. So far, it is only known, the bending angle in Area of the connecting link 8th to measure, but this leads to no spatial statement. According to the invention, it is accordingly 10 possible for the first time, the pipe bend 21 . 22 . 23 to determine and determine in the room with high precision.

The radius of curvature 25 . 26 of the two corrected traces 19 (2) and 19 (3) depends on the pipe bend and must be with both probes 2 . 3 be the same to confirm the accuracy of the pipe bend.

The 8th and 9 each show the measuring head 1 in different measuring positions in the form of a measuring head 1' and in the form of the measuring head 1'' and in the form of the measuring head 1'' ,

In 11 is the difference between a pushing operation and a pulling operation of the measuring head 1 in the sewer pipe 20 shown. At each side are possible positions of the measuring head 1 shown in the sewer pipe, and it can be seen that the measuring head rests on both the channel bottom and left on the channel wall or right on the channel wall.

Solid lines show which measuring positions of the measuring head 1 arise when the measuring head 1 in the direction of the arrow 11 through the sewer pipe 20 is pushed through.

This push operation leads to unnecessary bends of the entire measuring head 1 and therefore less accurate results compared to the train operation when the gauge head 1 in the direction of the arrow 12 (see dashed lines) through the sewer pipe 20 is pulled.

The layers shown on the left in dashed line show that the measuring head 1 only about always at the channel bottom or at least below a center line in the channel cross-section, and thereby a much more accurate statement about the position of the measuring head in the sewer pipe can be made as compared in overrun operation, where it according to the solid lines in 11 (Left illustration) can also occur that the measuring head is above the center line in the channel cross-section, whereby the accuracy of the location is affected.

However, both working methods, namely the push and the train operation, claimed as essential to the invention.

In 11 is therefore in dashed lines the train curve resulting motion 29 of the measuring head 1 shown, while in solid lines the pushing operation and a resulting motion curve 30 is shown.

Following the 10 will be mentioned that once the two probes 2 . 3 the two pipe bends 21 . 22 have passed through and get back to a straight piece, also the traces 19 (2) and 19 (3) in one position 27 unite and there both curves 19 to match.

LIST OF REFERENCE NUMBERS

1

probe

2

probe

3

probe

4

probe

5

Inertial sensor a

6

Inertial sensor b

7

Inertial sensor c

8th

link

9

link

10

supply line

11

arrow

12

arrow

13

measured curve

14

measured curve

15

measured curve

16

measured curve

17

measured curve

18

measured curve

19

corrected trace

20

sewer pipe

21

tube bending

22

tube bending

23

tube bending

24

distance

25

Radius of curvature (from 3)

26

Radius of curvature (from 2)

27

position

28

offset line

29

Movement curve (backwards)

30

Movement curve (forward)

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 102006036416 A1 [0007]

Claims (10)

Channel location system with a number of inertial sensors ( 5 . 6 . 7 ) which in measuring probes ( 2 . 3 . 4 ) on a measuring head ( 1 ) are arranged one behind the other and this measuring head ( 1 ) into a sewer pipe ( 20 ), each of the inertial sensors ( 5 . 6 . 7 ) when moving through the channel ( 20 ) a multi-dimensional measurement signal (X, Y, Z) corresponding to the current position in the channel ( 20 ), characterized in that the measuring head ( 1 ) of at least two measuring probes arranged one behind the other at a spatial distance from each other ( 2 . 3 . 4 ), and that in each measuring probe ( 2 . 3 . 4 ) at least three aligned in each direction of space inertial sensors ( 5 . 6 . 7 ) and that the inertial sensors ( 5 . 6 . 7 ) in the one measuring probe ( 2 ) are aligned in a first spatial direction, while in the second, adjoining measuring probe ( 3 ) the inertial sensors ( 5 . 6 . 7 ) in one of the first spatial direction of the inertial sensors ( 5 . 6 . 7 ) of the first measuring probe ( 2 ) deviating angular position are installed. Channel location system according to claim 1, characterized in that the inertial sensors ( 5 . 6 . 7 ) in the first measuring probe ( 2 ) at an angle between 60 degrees and 120 degrees to the inertial sensors ( 5 . 6 . 7 ) in the subsequent measuring probe ( 3 ) are arranged. Channel location system according to any one of claims 1 or 2, characterized in that (in the successive measuring probes 2 . 3 . 4 ) the identical inertial sensors ( 5 . 6 . 7 ) are arranged with approximately the same electrical properties. Channel location system according to one of claims 1 to 3, characterized in that by calculating the measured spatial coordinates of a first measuring probe ( 2 . 3 . 4 ) and the measured spatial coordinates of at least one further measuring probe ( 2 . 3 . 4 ) an exact position of the measuring head ( 1 ) in the sewer pipe ( 20 ) is determinable. Channel location system according to one of claims 1 to 4, characterized in that measurement data for position detection are obtained in train operation. Channel location system according to one of claims 1 to 5, characterized in that the measuring probes ( 2 . 3 . 4 ) by a link ( 8th . 9 ) are interconnected. Channel location system according to one of claims 1 to 6, characterized in that by at least two at different points of a raw bend ( 21 ) ( 2 . 3 . 4 ) the radius of curvature ( 25 . 26 ) of the raw bend ( 21 ) is determinable. Channel location system according to one of claims 1 to 7, characterized in that the measuring probes ( 2 . 3 . 4 ) are formed in the form of a ball arrangement in a measuring head. Channel location system according to one of claims 1 to 8, characterized in that the inertial sensors ( 5 . 6 . 7 ) measure the linear acceleration, the rotation rate and the earth's magnetic field in relation to the x, y and z axes. Channel location system according to one of claims 1 to 9, characterized in that the inertial sensors ( 5 . 6 . 7 ) have an integrated 3D magnetometer with a microprocessor, with the calculations of rolling, pitching and yawing in real time feasible.

Images