EP0419602A1

EP0419602A1 - Method and apparatus for determining movements in structures

Info

Publication number: EP0419602A1
Application number: EP19900903295
Authority: EP
Inventors: Günther SCHERBICHLER
Original assignee: Steirische Wasserkraft- und Elektrizitats-Aktiengesellschaft
Current assignee: Steirische Wasserkraft- und Elektrizitats-Aktiengesellschaft
Priority date: 1989-03-01
Filing date: 1990-02-27
Publication date: 1991-04-03
Also published as: AT395659B; HU901772D0; ATA45689A; HUT56447A; WO1990010193A1

Abstract

Un fil à plomb de mesure (9) est agencé sur une construction en hauteur, notamment un barrage en béton (1), entre une zone de suspension (8) et une zone de mesure (II). Les mouvements relatifs du fil à plomb dans la zone de mesure sont suivis afin de détecter des mouvements relatifs de la construction. Afin d'éviter des erreurs ultérieures d'ajustement de l'agencement de mesure (15) et d'obtenir des valeurs de mesure susceptibles d'être transmises à distance, on a prévu au moins deux marques de référence (24) fixes séparées par un écartement connu dans la zone de mesure (II), notamment deux fils à plomb qui y sont suspendus. Une unité de mesure (16, 17) de l'écartement, notamment une unité optique exempte de rétroaction, sert à mesurer l'écartement relatif entre le fil à plomb de mesure (9) et les marques de référence (24).A plumb line for measurement (9) is arranged on an overhead construction, in particular a concrete dam (1), between a suspension zone (8) and a measurement zone (II). The relative movements of the plumb bob in the measurement area are followed in order to detect relative movements of the construction. In order to avoid subsequent errors in adjusting the measurement arrangement (15) and to obtain measurement values capable of being transmitted remotely, at least two fixed reference marks (24) are provided, separated by a known spacing in the measurement zone (II), in particular two plumb wires which are suspended there. A gauge unit (16, 17), including a feedback-free optical unit, is used to measure the relative gauge between the plumb line (9) and the reference marks (24).

Description

Arrangement and method for confirming structural movements

Technical field

The invention relates to an arrangement for determining relative movements between two areas of different heights of a towering building, in particular a dam, with a measuring solder articulated in one area and a fixed position in the other area, the measuring area, the relative position of the measuring solder determining measuring device. Furthermore, the invention also relates to a method for determining relative movements of the type mentioned, the relative position of a measuring solder articulated in one area being determined by a measuring device fixed in the other area. State of the art

Arrangements and methods of the type mentioned are known and are used in particular in tall and tall structures, in which different loads cause horizontal deflections relative to the foundation or between different areas of the structure and the associated stresses. This applies, for example, to the wind pressure on free-standing tower-like buildings or to the dam mentioned in particular, in which the horizontal deflection of the upper crown area is mainly influenced by the accumulation height and the temperature.

Particularly in the case of dams, arrangements or methods of the type mentioned are used, in which the measuring plumb - more precisely its suspension - is arranged in a pipe which runs vertically over the entire or at least part of the height of the dam, which is relative to the thickness of the Dam has a small diameter. It is irrelevant whether the measuring plumb bob is a hanging plumb bob or a swimming plumb bob; the former is mostly suspended in the crown area of the dam by means of a low-friction cutting edge or the like and extends into the area of the base of the wall where the solder weight is immersed in a damping fluid; the latter is conversely usually articulated accordingly in the region of the wall base and is also connected via a wire or the like connected to a floating body arranged in the measuring range; there are also arrangements in which a hanging solder and a floating solder are used, each of which extends into the measuring range between their articulations. In all cases, relative horizontal movements between the articulation range of the measurement plumb and the measurement range can be determined via the deflections of the measurement plumb.

Various possibilities are known for measuring the relative position of the plumb line, which must be very precise in order to increase the informative value. In one case, a fine light beam is moved horizontally by hand in the measuring device until its shadowing can be observed by suspending the measurement plumb bob on a surface arranged behind it. The actual measured value can then be read off using a vernier scale on the adjustment handle. In addition to the fact that operating errors can occur relatively easily with this arrangement, there is always the risk that errors or changes in the basic adjustment between the measuring device and the plumb bob can occur in the mostly moist to wet environment due to various environmental influences at least unusable, if not extremely dangerous, incorrect measurements.

Furthermore, electrical measurements of the relative position of the measurement plumb bob are also known, for example, which work by means of electrical fields between the measurement plumb bob and the measurement device and by measuring inductive or capacitive quantities. The problem here is that in order to cover larger possible relative movements of the measurement plumb bob, large field strengths must be used, which in turn have non-negligible repercussions on the measurement plumb bob itself. In addition, there is also the risk of subsequent misalignments mentioned above with such devices.

Presentation of the invention

The object of the present invention is to improve an arrangement and a method of the type mentioned in such a way that the disadvantages mentioned of the known such arrangements and methods are avoided and that the relative movements mentioned are significant and reproducible even over long periods of time, in particular in a simple and reliable manner can be determined. According to the present invention, this is achieved with an arrangement of the type mentioned at the outset in that the measuring device has at least two reference marks fixed in the measuring area of the building at a known distance from one another, and also has a non-reactive, in particular optical, distance measuring unit, via which the Relative distance of the measurement plumb to the reference marks can be determined. The corresponding embodiment of the mentioned method consists in that the distance to at least two reference marks fixed in the measuring range is determined in order to determine the relative position of the measurement plumb bob.

The determination of the relative position of the measurement plummet is thus immediately reduced to a distance determination between the position of the measurement plumb bob and the reference marks fixed to the building, which completely eliminates the subsequent adjustment problems mentioned. Thus also needs beispiels-, after an exchange of the actual distance measuring in place any readjustment to be made because ^r ence brands ja the only relevant in this connection distance between the Refe¬ remains unchanged. The particularly optical, non-reactive measurement of the relevant distances contributes to increasing or maintaining the achievable accuracy.

According to a particularly preferred embodiment of the arrangement according to the invention, it is provided that the reference marks are formed by reference solders suspended in the measuring area. This ensures in a simple manner that the reference marks are at exactly the same distance over a relatively large vertical area in the area of the distance measuring unit without special clamping and adjusting devices and are parallel to the plumb line, so that changes in the height of the actual measuring plane cannot have any effect .

In a further embodiment of the arrangement according to the invention, the optical distance measuring unit has at least one line camera connected to an evaluation device, including measuring optics, which images at least two reference marks and the measuring plummet on the line array of the cell camera. This results in a very simple and reliable way to monitor the required relative distances quasi continuously and completely without feedback and, moreover, to transmit the respective measured values remotely to practically any location. It it is essentially irrelevant whether the actual evaluation device is arranged in whole or in part in the measuring range or in the area of a remote control room or the like, or whether the remote transmission takes place via corresponding lines or else wirelessly.

According to another preferred development of the invention, two line cameras offset at least approximately 90 ° in planes at least approximately perpendicular to the measurement plumb bob as well as two associated reference marks, each having essentially the same distance from the assigned line camera, are provided, or are made in accordance with the method further developed according to the invention determines the distances to two pairs of reference marks which are at least approximately perpendicular to one another in a plane which is essentially perpendicular to the plumb line. With dams, for example, tangential and radial movements can be determined, or measurement errors can be eliminated by inaccurate alignment of a single distance measuring unit.

According to a preferred further embodiment of the invention, the reference marks can be arranged outside the range of movement of the plumb line to be expected, which results in certain advantages in terms of measurement technology and limits the area to be monitored from the outset.

Although in some cases it can also be found that the above-mentioned line camera with ambient light can be found, an embodiment of the invention is advantageous, particularly for use in closed interiors, according to which a light source is arranged on the side opposite the line of measurement of the line camera. The shading of this light source by the plumb bob or the reference marks can easily be converted into the corresponding measured value on the line camera or on the line array of this camera. Apart from that, of course, a kara eraside lighting with correspondingly inverse image representation could also be provided.

According to a further embodiment of the invention, the light source arranged behind the measuring solder emits diffuse light over the entire width of the movement range of the measuring solder to be expected and preferably has a light-emitting diode array with an upstream diffuser. This results in advantageous conditions for the measurement with the line camera and thus increased evaluation reliability. The light-emitting diodes which are preferably used can, for example, emit monochrome red light in the wavelength range of 650 nm, which on the one hand has the advantage that the sensitivity of the line array can be matched precisely to this wavelength and on the other hand enables improved imaging, since color imaging errors drop away; vorte lhaft particularly is that most common lenses are adjusted from the outset, among other things, to the red light mentioned.

In order to be able to compensate for errors due to changing unsharpness of the moving measuring plummet, particularly in connection with measurements carried out using only a single line camera, another development of the invention provides that the light source has essentially parallel light over the entire width of the expected range of movement of the measuring plumb bob emits and that between the plumb bob or reference marks and measuring optics of the line camera, a focusing screen is arranged in the beam path of this light. Since the possible range of movement of the measurement plumb bob is illuminated in parallel, the aforementioned error possibilities are eliminated. In addition, the beam set would, when moving the plumb line on a circular path in diffuse or diverging light, provide exactly two values - the use of parallel light together with the aforementioned focusing screen again results in clear assignments.

According to an embodiment of the invention which is advantageous in the last-mentioned context, it is provided that the light source has a point light source with a collimator, which allows the stated requirement to be easily implemented.

In order to prevent insects or similar small organisms from being attracted by the light source of the measuring device, which naturally can disturb the measurement, it is provided according to another advantageous development of the invention that the light source is clocked and emits light pulses, which leads to the problems mentioned eliminated. In addition, the known clock rate then also gives the possibility of accepting signals arriving at the row array only in accordance with the clock rate, which together with the possibility of using selective filters which are matched to the light source used, results in very good independence from sensitive ambient light. Brief description of the drawing

The invention is explained in more detail below with reference to the exemplary embodiments shown schematically in the drawing.

1 shows a schematic cross section through a dam with an arrangement according to the present invention,

FIG. 2 shows a partially schematic plan view of a measuring device provided in area II according to FIG. 1,

3 shows a detail from FIG. 2 on an enlarged scale,

4 shows a schematic diagram for the arrangement according to FIG. 3,

Fig. 5 is a diagram to illustrate the relationship between the camera scale and transmission scale and

Fig. 6 is a schematic diagram similar to Fig. 4 of a differently designed arrangement according to the invention.

According to FIG. 1, a pipe or a shaft 4 running vertically from the crown 2 to the base 3 of the wall is provided in the central region of a dam 1, which is accessible in the lower region via a cross passage 6 coming from the air side 5. For guidance only, it should be noted here that the shaft 4 has about 30 cm in diameter above the transverse aisle 6 and - like the transverse aisle 6 itself - about 1 cm in diameter in the case of such structures.

In the area of the crown 2 of the dam 1, a measuring plunger 9 is articulated to a control room 7 or the like at a point 8, the suspension 10 of which, in the form of a wire, thin steel cable or the like, runs through the shaft 4 and its plumb weight 11 in the area the wall base 3 is arranged and mostly immersed in a damping basin with water or a similar suitable liquid in a manner not shown here. If the water level 12 in the reservoir 13 is different and if the temperature of water and ambient air fluctuates there are different deflections of the area of the crown 2 with respect to the central area of the wall or with respect to the wall foot 3, mainly in the direction of the double arrow 14. These deflections are determined by the fact that in a measuring area II at the mouth of the transverse passage 6 to the shaft 4 a measuring device 15, shown schematically in FIG. 2 from above, is provided, by means of which the relative position of the measuring solder 9 to the surrounding measuring area II is determined, which allows a direct statement about the relative movement of the point 8 of the suspension of the measuring solder 9 .

2, the measuring device 15 has two non-reactive, optical distance measuring units 16, 17, the alignment axes 18, 19 of which at least approximately intersect in the area of the measurement solder 9 (or its suspension 10) (here, for reasons of arrangement, there is an offset made in height) and in the plane of FIG. 2 include an angle of at least approximately 90 °. The distance measuring units 16, 17 each have a line camera 20 connected to an evaluation device (not shown) together with measuring optics 21 (see in particular FIG. 3), which are directed along the alignment axis 18, 19 at the measuring plunger 9. A light source 22 is arranged on the side opposite the line sensor 20 with respect to the measurement plumb 9, which emits diffuse light over the entire width of the range of movement of the measurement plumb line 9 to be expected and preferably has a light-emitting diode field 23 with an upstream diffuser.

In addition to the measuring plumb 9, reference marks 24 fixed in the measuring region relative to the dam in the measuring region are arranged at a known distance from one another in the area monitored by the line cameras 20, with two reference marks 24 arranged outside the expected range of movement of the measuring plumb 9, one essentially perpendicular to it Connected line camera 20 are assigned. Since the movement of the dam 1 according to FIG. 1 is naturally much greater in the direction of the double arrows 14 (in the so-called radial direction) than in the perpendicular (tangential) direction, the distance is also assigned to the distance measuring unit 17 in FIG. 2 two reference marks 24 are substantially larger than the reference marks assigned to the distance measuring unit 16. The reference marks 24 themselves are formed in a manner not shown here from reference solders suspended in the measuring area II via a suitable suspension device on the dam 1, which are therefore always parallel to one another and to the measurement solder 9, regardless of the relative height at which the two Line cameras 20 measure the relevant distances.

3, the distance measuring unit 17 from FIG. 2 is shown again on a somewhat larger scale and in somewhat more detail. It can also be seen from this how the shadows of the light-emitting diode array 23 of the light source 22 representing the two reference solders 24 and the measurement solder 9 are imaged on the line array 25 of the line camera 20 via the measuring optics 21, which then do not refer to the corresponding information here passes on the manner shown for processing.

The illustration of the reference marks 24 and of the measurement plumb 9 via the measurement optics 21 on the line array 25 is shown again schematically enlarged in FIG. 4. The scale transformation from the camera scale plotted horizontally in FIG. 5 to the transmission scale plotted vertically in the figure mentioned is carried out in a known manner using a simple straight line equation.

In the arrangement according to FIG. 6, a light source 22 is provided, which emits essentially parallel light over the entire width of the range of movement of the measurement plumbing 9 to be expected, which is realized via a point light source 26 with a collimator 27. Between the measuring solder 9 or reference marks 24 and the measuring optics 21, a focusing screen 28 is arranged in the beam path of the light, with the focusing screen now being imaged via the optics 21 onto the line array 25 of the line camera (not shown). In this way, measurement errors due to unsharpness are eliminated due to a movement that is not exactly perpendicular to the respective alignment axis 18, 19 (FIG. 2).

At the lowest temperature and full accumulation, the dam 1 according to FIG. 1 moves furthest to the air side and at the highest ambient temperature and drained water to the water side. The magnitude of this movement is approximately one per thousand of the wall height for actually constructed dam walls, which means that 50 m wall height for example approx. 50 mm maximum deflection. The camera scale (according to FIG. 5) is determined by the number of exposure meter elements of the line scan camera (for example 256, 512, 1024, 2048 ...), which in turn determines the resolution of the entire distance measuring unit in relation to the image plane. For example, a 10 cm image field with a 512 element camera gives a resolution of 0.1 mm.

While the reference marks 24 or reference solders assigned to the distance measuring unit 17 have a distance of about 6 cm in the above example, the reference solders 24 assigned to the distance measuring unit 16 monitoring the tangential movements are arranged at a relative distance of only about 1 cm , since the tangential movements of a dam are usually negligible and mostly only serve to check the correct alignment of the measurement of the radial movements. This can be different, for example, in tower-like structures in which the two directions have equal rights.

The processor used for evaluating the signals of the line scan camera (s) can be used in a very simple manner according to the current state of the art, e.g. furthermore also monitor the time function of the imaging movement and thus distinguish the moving measuring plumb from the stationary reference marks. This results in a calculation possibility not only for an interpolation between the reference marks but also for the entire image area with additional extrapolation, which also makes it easy to determine the position of the measurement solder outside the reference marks. The adjustment aids can also be derived with the aid of such a processor, wherein the processor can indicate how many "wires" are recognized and by how many image increments the reference marks are asymmetrical in the image. By determining the actual image widths of the reference marks, statements can also be made about the sharpness of the image. Furthermore, by comparing the existing images on the line array, images that are too small (for example caused by cobwebs or the like) can be eliminated by the processor.

Instead of the design of the plumb line 9 shown in FIG. 1 as a hanging plumb bob attached to the wall crown 2, the plumb line could also be called floating solder to be formed, which is articulated in the region of the wall base 3 and has a floating body mounted floating above and serving to tighten the suspension. In the case of relative movements of the measuring area then located on the floating body to the area of the suspension or articulation of the floating solder, the distance measurements can again be carried out completely identically as described above with reference to the hanging solder. In the case of actually constructed dam walls, hanging solder and floating solder are also combined in such a way that the relative movements of the crown to the foot of the wall are determined by means of a hanging solder which is essentially continuous from the crown to the base of the wall and that the relative movements of the The center of the wall to the base of the wall can be determined so that the deflection of the central area can also be determined. Furthermore, of course, several measuring devices of the type mentioned, which are provided distributed over the width of the dam, are also possible with different combinations of hanging and floating solders.

Claims

Claims;

1. Arrangement for the determination of relative movements between two areas of a tower that have different ground clearance

Building, in particular a dam, with a measuring solder articulated in one area and a measuring device fixed in the other area, the measuring area, which determines the relative position of the measuring solder, characterized in that the measuring device (15) has at least two in the measuring area (II) of the structure (1) fixed reference marks (24) at a known distance from one another, and a non-reactive, in particular optical, distance measuring unit (16, 17), by means of which the relative distance of the measuring plumb (9) to the reference marks (24) can be determined.

2. Arrangement according to claim 1, characterized in that the reference marks (24) are formed by reference solders suspended in the measuring range (II).

3. Arrangement according to claim 1 or 2, characterized in that the optical distance measuring unit (16, 17) has at least one line camera (20) connected to an evaluation device, including measuring optics (21), which has at least two reference marks (24) and the measuring plummet (9) on the line array (25) of the line camera (20).

4. Arrangement according to claim 3, characterized in that two line cameras (20) offset in at least approximately vertical planes at least approximately perpendicular to the measuring plunger (9) and in each case two associated, essentially the same distance from the assigned line camera (20). having reference marks (24) are provided.

5. Arrangement according to one of claims 1 to 4, characterized in that the reference marks (24) are arranged outside the expected range of movement of the measuring plummet (9).

6. Arrangement according to one of claims 3 to 5, characterized in that a light source (22) is arranged on the opposite side with respect to the measurement solder (9) of the line camera (20).

7. Arrangement according to claim 6, characterized in that the light source (22) emits diffuse light over the entire width of the expected range of movement of the measurement plummet (9) and preferably has a light-emitting diode array (23) with an upstream diffuser.

8. Arrangement according to claim 6, characterized in that the Licht¬ source (22) over the entire width of the expected range of movement of the measuring plunger (9) emits substantially parallel light and that between the plumb bob (9) or reference marks (24th ) and measuring optics (21) of the line camera (20) a focusing screen (28) is arranged in the beam path of this light.

9. Arrangement according to claim 8, characterized in that the Licht¬ source (22) has a point light source (26) with collimator (27).

10. Arrangement according to one of claims 6 to 9, characterized in that the light source (22) is clocked and emits light pulses.

11. A method for determining relative movements between two areas of a towering structure having different ground clearance, in particular a dam, the relative position of a measuring solder articulated in one area being determined by a measuring device fixed in the other area, the measuring area, characterized in that that the distance to at least two reference marks fixed in the measuring range is determined in order to determine the relative position of the measurement solder.

12. The method according to claim 11, characterized in that the distance measurement is performed without reaction, in particular optically, and the respective measured values are transmitted remotely.

13. The method according to claim 11 or 12, characterized in that the distances to two, in a plane substantially perpendicular to the plumb line at least approximately perpendicular to each other aligned pairs of reference marks are determined.