PL239595B1 - Displacement measurement device - Google Patents

Abstract

The method of measuring displacements, using the device that is the subject of the application, consists in that the reference frame (3), having a defined Cartesian coordinate system xryrzr, in which the position of reference signals (11) is determined, is connected, by means of fastening screws (10), to the reference element (2). The measuring target (4), having a defined Cartesian coordinate system xtytzt, in which the position of monitored signals (12) is determined, is attached by means of fastening screws (10) to the measuring element (1). A fiber optic plumb line (14), having a defined Cartesian coordinate system xpypzp, is attached to the reference frame (3). The electronic camera (6), having a defined Cartesian coordinate system xkykzk, is placed so that the lens is directed towards the reference frame (3), the measuring target (4) and the spatial suspended target (16). Then, images taken with an electronic camera (6) are periodically recorded and sent to the central data recording and processing system (CRPD) (7), where they are archived and processed based on appropriate calculation procedures. This allows determining the relative displacements of the measuring target (4) in relation to the reference frame (3), in relation to the Cartesian coordinate system xkykzk of the electronic camera (6), related to the vertical line realized by the zp axis of the Cartesian coordinate system xpypzp of the fiber optic plumb line (14).

Description

The subject of the invention is a device for measuring relative displacements, such as: translation and rotation, especially on natural objects (inanimate nature, e.g. rock blocks) and engineering objects (e.g. buildings, structures, etc.).

In the case of measurements of expansion joints, cracks in the structure of buildings and structures, and shifts of tectonic structures in fault zones, relative measurement methods are used, along with specialist instrumentation. Observations of displacements are performed using: geodetic and photogrammetric methods, which allow for relating their results to fixed reference systems, as well as mechanical devices and sensors that use physical phenomena in measurements, such as: inductance, capacitance or resistance, which allow for relating the obtained measurement results to non-fixed reference systems.

Modern geodetic supervision, at the stages of creation, diagnosis and forecasting of deformations, strains and displacements occurring on the examined objects, uses the latest achievements in the field of precision mechanics and optoelectronics. This has contributed to the construction of modern measuring devices that allow for the performance of automated and telemetric observations in real time.

The principles of relative and absolute displacement measurements are described in numerous specialist literature [Lazzarini T.: Geodetic measurements of displacements of buildings and their surroundings, PPWK, Warsaw 1977; Bryś H. and Przewłocki S.: Geodetic methods of measuring displacements of buildings, PWN, Warsaw 1998] and in applicable national standards [PN-N-02211: Geodesy - Geodetic determination of displacements - Basic terminology, PKN, 2000] and international standards [Engineer Manual EM 1110-2-1009: Structural Deformation Surveying, U.S. Army Corps of Engineers, Washington 2018].

The description of patent PL 207417 provides a device designed to measure the value of relative displacement of objects, which is equipped with a light source and a linear optical fiber matrix, from which light signals are transmitted via optical fibers to a measuring system containing a photodetector connected to an amplifier. A movable diaphragm is placed between the light source and the linear optical fiber matrix, the optical fibers of which are connected to the measuring system, with transparent and opaque strips placed alternately along the diaphragm.

In addition, a system for measuring changes in length between measuring marks is known from the description of the PL 217348 patent, concerning measurements of relative changes in the length of sections, as a result of which deformations of the ground or an object are determined between the measuring marks defining a given section. A characteristic feature of this invention is that a rod is permanently attached to the measuring mark defining one of the ends of the measured section, which is suspended through a disc mounted on a measuring plate, placed on the second measuring mark defining the other end of the section. A camera and a linear scale are mounted on the measuring plate, and a reading indicator is attached to the rod, with the end of the rod equipped with a weight. The image of the reading indicator against the background of the linear scale is recorded by a camera and sent via power supply and signal cables to the recorder.

Mechanical devices are known [GOECKE catalogue: Der Ausruster fur die Vermessungstechnik GK 7, p. 59, www.goecke.de], equipped with scales, for monitoring cracks in the structure of a building in two or three directions (Riss-Spion 101-RS1, Riss-Spion 101-RS2, Riss-Spion 101RS3 and Rissmonitor 101-TT4). Depending on the predicted displacements, these devices are mounted on the tested object in different configurations. With the use of these devices, it is possible to monitor the relative displacements occurring on the tested objects. These devices consist of two mutually sliding plates on which linear scales are applied with appropriate accuracy. These plates can be made of transparent or opaque material.

The TM-71 feeler gauge is known from the literature [Kostak B., 1991: “Combined indicator using moire technique”, Balkema, Rotterdam, ISBN 9054100257, 53-61]. The device consists of two indicators oriented in two perpendicular planes xy and xz. Each indicator consists of a pair of glass plates with etched spiral gratings, with hyperbolic striations (circular disc), and linear ones, with parallel striations, which define two rectangular interference surfaces. The arms of the TM-71 feeler gauge, attached to the rock blocks on the wings of the fault, transfer their relative movements, which are then recorded by the main and linear gratings of the feeler gauge. The observed Moire fringes on the spiral gratings are created as a result of the superposition of regular geometric structures (spirals), etched on the glass plates, at the moment of changing

PL 239 595 B1 position of one plate relative to another. The change in the position of the plates is related to the relative displacement of the shell blocks. On the other hand, Moiré fringes on linear gratings are created as a result of the difference in light density when passing through linear gratings rotated with respect to each other as a result of the rotation of the shell blocks.

There is a known method of processing images acquired using metric and non-metric cameras. The method of processing images with any angle of inclination relative to the adopted reference plane described in the publication by J. Butowtt and R. Kaczyński [Butowtt J. and Kaczyński R.: "Fotogrammetry", WAT, Warsaw 2003, pp. 23+39] is implemented on the basis of the principles of projective geometry known and used in photogrammetry. The method of flat projective transformations is based on the transformation of a plane into a plane, using at least four corresponding homologous points, assuming that no three points, out of these four, lie on one straight line. This processing method allows for the elimination of perspective distortions resulting from the non-parallelism of the planes being processed. This publication (on pp. 126+130) also describes the camera calibration procedures known and used in photogrammetry.

The problem of the indicated state of the art is that mechanical devices do not allow for the automation of the method of observations and do not allow for sending the results of these observations to the recording unit. Another limitation, noticed in the descriptions of the devices used, is the small measurement ranges and the need for continuous access to measurement points in the places where the observations are conducted. In known devices, the phenomenon of interference and analysis of Moiré fringes can also be used, which in fact allow for obtaining high measurement accuracy, but are limited to a small observation space.

Therefore, it turned out that introducing the photogrammetric method to the measurement set allows for automatic recording and transmission of measurement results and remote measurement on the acquired images, while the use of a fiber optic plumb line allows for relating measurement results to the plumb line. The fiber optic plumb line allows for determining the tilt angles of the measured object in two mutually perpendicular directions.

The applied optical fiber plumb line has a base to which the plumb line support is attached. The plumb line support has a suspended optical fiber, the upper end of which is illuminated by a light source, and the lower end is equipped with an attenuator. The course of the plumb line is determined by the photogrammetric method, based on the measurement of the position of the optical fiber end.

The purpose of the invention is to develop a measuring device for measuring displacements, which will enable, through photogrammetric processing of recorded images of the measuring target against the background of the reference frame, in an automatic and telemetric manner, determining changes in position, i.e. shifts and rotations of one measuring element relative to another on the object, in relation to the plumb line. The developed invention can be used as a single set or multiplied on the elements of the object.

The essence of the invention is that the device comprises a reference frame with at least four reference signals placed on it, which are placed in one plane XrZr, in the local Cartesian coordinate system XryrZr, wherein if the number of reference signals is m, then the number of reference signals which cannot lie on one straight line is m-1, and comprises a measuring target with at least four monitored signals, which are placed in one plane XtZt, in the local Cartesian coordinate system XtytZt. If the number of monitored signals is k, then the number of monitored signals which cannot lie on one straight line is k-1. The electronic camera has a defined Cartesian coordinate system XkykZk and is connected to the central data recording and processing system and is directed with its lens towards the reference frame and the measuring target. In addition, a fiber optic plumb line is attached to the reference frame, which has an electronic plumb line camera in its lower part, connected to the central data recording and processing system (CRPD), and a plumb line support, which has an opening in the middle of its upper part, in which an optical fiber of length d is suspended using a fiber optic suspension, the upper end of which is illuminated by a light source, and the fiber optic plumb line has a defined Cartesian coordinate system XpypZp.

It is advantageous if the central data recording and processing system is a portable microcomputer.

It is also advantageous when the reference signals take the form of squares, especially white and/or black.

PL 239 595 B1

It is also advantageous if the reference signals take the form of either concentric circles, or a circle, or a cross, or a coded character.

It is also advantageous if the reference signals are regularly arranged on the reference frame.

It is also advantageous when the controlled signals take the form of squares, especially white and/or black.

It is also advantageous when the controlled signals take the form of either concentric circles, a circle, a cross or a coded sign.

It is also advantageous if the controlled signals are regularly distributed over the reference frame.

It is advantageous if the device includes a boom.

It is also advantageous if the electronic camera is releasably connected to the boom by means of a coupling screw.

It is also advantageous if the electronic camera is permanently connected to the boom.

It is also advantageous if the boom is attached by means of mounting screws to the reference element independently of the reference frame.

It is also advantageous if the boom is permanently attached to the reference frame.

It is also advantageous if the boom has the form of an L-shaped flat bar.

It is also advantageous if the electronic camera is set at an observation position unrelated to the measured object.

It is also advantageous if the measuring disc is located inside the reference frame.

It is also advantageous when the corresponding axes of the Cartesian coordinate systems: the measuring disc xtytzt and the reference frame XryrZr in the output measurement are approximately parallel to each other.

It is also advantageous when the electronic camera is wirelessly connected to the central data recording and processing system.

It is also advantageous when the yk axis of the Cartesian coordinate system of the electronic camera is approximately perpendicular to the XrZr plane defined by the Cartesian coordinate system of the reference frame.

It is also advantageous when the corresponding axes of the Cartesian coordinate systems: the electronic camera XkykZk and the reference frame XryrZr in the output measurement are approximately parallel to each other.

It is also advantageous if the yk axis of the Cartesian coordinate system of the electronic camera is directed approximately centrally to the reference frame.

It is also advantageous if the reference frame has the form of a rectangular frame or a hoop.

It is also advantageous if the measuring disc is in the shape of a rectangle or a circle.

It is also advantageous if the fiber optic riser is releasably connected to the reference frame by means of coupling screws.

It is also advantageous if the fiber optic riser is permanently connected to the reference frame.

It is also advantageous when, after connecting the optical fiber plumb line to the reference frame, the Cartesian coordinate systems of the reference frame XryrZr and the optical fiber plumb line XpypZp are parallel to each other.

It is also advantageous if the optical fiber is a single optical fiber with a circular cross-section.

It is also advantageous when the optical fiber is a fiber optic cable in the form of a bundle with a number of fibers greater than one.

The applied fiber optic plumb line is a measuring element in which the plumb line coincides with the force of gravity running along the fiber optic, which is the fiber optic plumb line. The angular deflection of the fiber optic, of known length d, from the plumb line is determined based on the measurement of the position of the lower, luminous end of the fiber optic, using the photogrammetric method, using an electronic camera.

The relationship between the Cartesian and coordinate systems: reference frame 3 (XryrZr) relative to the electronic camera 6 (XkykZk) is determined based on formula 1, using the appropriate software in CRPD 7. This formula is a mathematical notation of the spatial transformation between two Cartesian coordinate systems.

PL 239 595 BI

X _k = M^T _r + T* (1) where:

- M _r is the rotation matrix describing the angular relationship between the coordinate system of the reference frame (χ _Γ γ _Γ ζ _Γ ) and the coordinate system of the electronic camera (XkykZk); ------»

- Tr is the translation vector defining the offset of the origin of the reference frame coordinate system (x _r yrZ _r ) from the origin of the electronic camera coordinate system (XkykZk);

- is a vector defining the position of a given point in the coordinate system of the reference frame (x _r y _r z _r );

- is a vector defining the position of a given point in the coordinate system of the electronic camera (x _k ykZ _k ).

The rotation matrix is a square matrix that has dimensions of 3x3 elements in the Euclidean 3D space (formula 2). The nine coefficients of the rotation matrix are real numbers that are the relationships of trigonometric functions (sines and cosines) of three rotation angles (so-called Euler angles, marked with Greek letters): omega (»), phi (¢^) and kappa (/&), whereby, first, the rotation of the reference frame system 3 (x _r y _r z _r ) is applied by the omega angle (ωτ) around the x _r axis (the axis of the first rotation), then by the phi angle (¢^) around the y _r axis (the axis of the second rotation) and finally by the kappa angle (/&) around the z _r axis (the axis of the third rotation). This is the so-called ω-φ-κ convention. The angles ca, cpr, κ define the rotation of the coordinate system of the reference frame 3 (χ _Γ γ _Γ ζ _Γ ) with respect to the camera coordinate system 6 (XkykZk).

^m nm _2i ^m 3i nii2 m ₁₃ m ₂₂ m ₂₃ ^m 32 ^m 33 .

(2) where:

m 11 - COS ęY COS Kr mi2 = cos ca sin Kr + sin ca sin cpr cos Kr

Π113 = Sin ca Sin Kr - COS ca Sin Cf>r COS Kr m21 = - COS cpr sin Kr m22 = COS ca COS Kr - sin ca sin cpr sin Kr m23 = sin ca COS Kr + COS ca sin cpr sin Kr m31 = sin cpr m32 = - sin ca cos cpr m33 = COS ca COS cpr

In the problem inverse to the one presented above, in the so-called κ-cp-co convention, the angular dependence is determined between the Cartesian coordinate system of the electronic camera 6 (XkykZk) with respect to the coordinate system of the reference frame 3 (x _r yrZ _r ). This dependence is described, assuming the orthogonality of the rotation matrix, by formula 3, from which it follows that the inverse of the orthogonal matrix is equal to its transpose. Hence, the matrix defining the angular dependence between the coordinate system of the electronic camera 6 (XkykZk) and the coordinate system of the reference frame 3 (x _r y _r z _r ), is presented by formula 4.

M- ¹ = (Μ^Γ ¹ = (MW = R ^r _k = R (3)

*1 = = mu m ₁₂ ^m 2 and m ₂₂ ^m 3i' m ₃₂ (4) m ₁₃ m ₂₃ ^m 33

ψν

In order to determine the translation vector 'k, which specifies the shift of the origin of the coordinate system of the electronic camera 6 (XkykZk) from the origin of the coordinate system of the reference frame 3 (x _r y _r z _r ), nr Tk based on the known rotation matrix ki of the translation vector ¹ r, formula 5 is used.

PL 239 595 BI

Tl = -Rl Tl (5)

The mathematical notation of the inverse transformation, i.e. the transformation between the Cartesian coordinate system of the electronic camera 6 (XkykZk) and the Cartesian coordinate system of the reference frame 3 (x _r y _r z _r ), is given by formula 6.

T _r = R ^r _k -r _k + Tź (6)

Based on the matrix ^r (or ^k) (formulas 2 and 4), the rotation angles c&, w (formula 7) can be determined. The result of the calculations is obtained in radians, while in order to convert to degrees, the result should be multiplied by the conversion factor 1807π.

= — atan2(m ₃₂ ,m ₃₃ ) φ _τ = asin(m ₃₁ ) (7)

Then, in a manner analogous to that presented above, the relationship between the Cartesian coordinate systems of the measuring target 4 (xtytZt) and the electronic camera 6 (XkYkZk), p and , i.e. the rotation matrix (defining the angular relationship between the coordinate system of the electronic camera 6 (XkykZk) and the coordinate system of the measuring target 4 (xtytZt)) and the transit vector k (defining the shift of the origin of the coordinate system of the electronic camera 6 (XkykZk) from the origin of the coordinate system of the measuring target 4 (xtytZt)) are determined.

Based on the images of the position of reference signals 11 and controlled signals 12 recorded at times to (initial measurement time) and ti (current measurement time), using the software, the displacements (fi ¹ 1) and rotations (i ^Λ ί) are determined between the Cartesian and coordinate systems: of the measuring target 4 (xtytZt) with respect to the reference frame 3 (x _r y _r z _r ), in the homogeneous Cartesian coordinate system of the electronic camera 6 (XkYkZk) (Fig. 4 and Fig. 5).

Based on the calculated values of the corresponding translation vectors and the corresponding rotation matrices, the mutual position of the measuring element 1, represented by the measuring disc 4, relative to the reference element 2, represented by the reference frame 3, is determined.

Depending on the predicted displacement values of elements 1 and 2 of the measured object and the required measurement accuracy, the size of the device (including the number and size of controlled signals 12 and reference signals 11) and the method of setting the electronic camera 6 and its technical parameters should be selected. It should also be remembered that the measurement results, along with the increase in the distance of photographing, may have a greater impact on the environmental conditions (e.g. temperature gradient and air humidity, atmospheric pressure, sunlight, dust or vibrations), resulting in a decrease in the accuracy of the measurements performed. The influence of the above environmental factors can be limited by monitoring the environmental and atmospheric parameters with additional sensors. In such a case, the results from these sensors should be taken into account using appropriate calculation procedures in CRPD 7, when processing images recorded by the electronic camera 6.

The subject of the invention is presented in an example embodiment in the drawing, in which: fig. 1 - shows a device for measuring displacements in an axonometric projection, in the absence of a connection between the reference frame and the boom, fig. 2 - shows the device in an axonometric projection, with the connection between the reference frame and the boom, fig. 3 - shows the device in an axonometric projection without a boom, with the electronic camera set on an independent observation position, which may be a tripod or an observation pole, fig. 4 - shows the relationship between the Cartesian and coordinate systems: of the electronic camera XkYkZk, reference frame x _r yrZ _r , fiber optic plumb line ΧρΥρΖρ and measuring target XtytZt in the initial measurement position to, fig. 5 - shows the relationship between the Cartesian and coordinate systems: of the electronic camera XkYkZk, reference frame x _r yrZ _r , fiber optic plumb line x _P y _P z _p and the measuring target XtytZt in the current measuring position ti, while Fig. 6 shows the relationship between the Cartesian and coordinate systems: electronic camera XkYkZk, reference frame x _r yrZ _r , fiber-optic plumb line x _P y _P z _p and the measuring target XtytZt in the next measuring position at time t2, at the inclination of: the reference frame, the fiber-optic plumb line and the electronic camera, as well as the measuring target.

PL 239 595 B1

Example 1. The device for measuring displacements, as in Fig. 1, consists of a measuring disc 4, attached by means of fastening screws 10 to the measuring element 1 of the measured object, and of a reference frame 3, attached by means of fastening screws 10 to the reference element 2 of the measured object. A fiber optic riser 14 is attached to the reference frame 3 with coupling screws 9, having an electronic riser camera 15, connected by a transmission cable of the electronic riser camera 16 to the central data recording and processing system (CRPD) 7 and a riser support 17. In the middle of the upper part of the riser support 17, through an opening 20 using a fiber optic suspension 18, an optical fiber 21 of length d is suspended, the upper end of which is illuminated by a light source 19. On the other hand, the lower end of the optical fiber 21 is equipped with a weight 22 and is signaled by point P, which is observed by the electronic riser camera 15. The reference frame 3 has reference signals 11 and has a defined Cartesian coordinate system of the reference frame XryrZr. The measuring target 4 has controlled signals 12 and has a defined Cartesian coordinate system of the measuring target XtytZt. The fiber optic plumb line 14 has a defined Cartesian coordinate system of the fiber optic plumb line XpypZp. A boom 5 is attached to the reference element 2, to which the electronic camera 6 is attached by a coupling screw 9. The electronic camera 6, which has its defined Cartesian coordinate system XkykZk, is connected by a transmission cable 8 to the central data recording and processing system (CRPD) 7. The device for measuring displacements, made as in example 1, is designed to determine the predicted displacements of elements 1 and 2 of the measured object in the range from 0.0 mm to 50.0 mm, with a measurement accuracy of tenths and hundredths of a millimeter. The rotation of the elements of the measured object is determined at the level of thousandths of a degree. The displacement measurements performed are referred to the plumb line realized by the Zp axis of the Cartesian coordinate system XpypZp of the optical fibre plumb line 14. The size of the device (including the number and size of the controlled signals 12 and reference signals 11 as well as the method of setting the electronic camera 6 and its technical parameters are selected after a thorough analysis of the case. The technical parameters of the electronic camera 6, including the size and resolution of the matrix and the lens used, should be selected so as to take into account the dimensions of the reference frame 3 and the dimensions of the controlled signals 12 and reference signals 11 used. In the case of the electronic camera of the plumb line 15, the resolution of the matrix and the lens used should be selected so as to optimally observe and record the position of the end of the optical fibre 21, represented by point P. The recording of images with the electronic camera 6 and the electronic camera of the plumb line 15 should be carried out under established lighting conditions.

Method of measuring displacements:

Before starting to measure displacements on the measured object, the measuring target 4 is mounted, using mounting screws 10, on the measuring element 1, respectively. In turn, the reference frame 3 is mounted on the reference element 2, with the fiber optic plumb line 14. The electronic camera 6 is mounted on the boom 5, with the boom 5 being connected to the reference element 2 (fig. 1). The electronic camera 6 is connected by a transmission cable 8 to the central data recording and processing system (CRPD) 7, while the measuring target 4 is placed so that it is inside the reference frame 3 and that the Xy planes of the Cartesian coordinate systems: XryrZr and XtytZt are parallel to each other. After connecting the optical fiber plumb line 14 with the reference frame 3, the Cartesian coordinate systems: the reference frame XryrZr and the optical fiber plumb line XpypZp are also parallel to each other. The object and measuring device prepared in this way are suitable for cyclic observations, in the assumed time interval, and allow determining the displacements occurring on the measured object. The determined displacements refer to the mutual displacements of the elements: measurement 1 and reference 2.

Before starting the actual measurements, the device according to the invention is calibrated. In the case of the reference frame 3, the position of the reference signals 11 is determined in the Cartesian coordinate system XryrZr of the reference frame 3. For the measuring target 4, the position of the controlled signals 12 is determined in the Cartesian coordinate system XtytZt of the measuring target 4, and in the case of the fiber-optic plumb line 14, the directions and values of the angular deflections of the plumb line, of known length d, are determined based on the measurement of the position of the lower, luminous end of the fiber-optic cable 21 (control point P), by the photogrammetric method, using the electronic camera of the plumb line 15, in the Cartesian coordinate system XpypZp of the fiber-optic plumb line 14. For the electronic camera 6 and the electronic camera of the plumb line 15, the elements of the internal orientation are determined together with the distortion parameters of the optical system, using known photogrammetric procedures. For the fiber-optic plumb line 14, the position is determined

PL 239 595 BI zero coordinate system of the optical fiber plumb line χ _Ρ γ _Ρ ζ _ρ , in which the angular inclination of the z axis _p is 0°. The measuring target 4 and the reference frame 3 are positioned in the selected depth of field range of the electronic camera 6, at the set shooting distance.

During the initial measurement at time to (fig. 4), and then the current measurement at time ti (fig. 5), the following images are recorded with the electronic camera 6: the reference frame 3 with reference signals 11 and the measuring target 4 with controlled signals 12, and the images of the position of the end of the luminous optical fiber 21 (control point P) are recorded with the electronic camera 15 of the vertical beam 15 (fig. 1).

If insufficient lighting intensity occurs when photographing the reference frame 3 and the measuring target 4, additional lighting of the mentioned elements of the device is introduced during the given measuring period.

Images recorded with electronic camera 6 are sent to the CRPD 7 system, where they are processed and archived.

The sample measurement is performed with the following assumptions:

• electronic camera 6, equipped with a fixed camera lens of 50.00 mm;

• reference frame 3 is rectangular and measures 300 mm by 200 mm;

• the measuring disc 4 is also rectangular and has dimensions of 120 mm by 140 mm;

• the distance of the electronic camera 6 from the reference frame 3 (yk) is 200.00 mm;

• during the output measurement (at time to) the corresponding axes of the Cartesian coordinate systems of the measuring disc (xtytZt) and the reference frame (x _r y _r z _r ) are parallel to each other, i.e. the rotation matrix (the matrix describing the angular relationship between the coordinate system of the measuring disc (xtytZt) and the coordinate system of the reference frame (x _r y _r z _r )) is a unit matrix;

• the yk axis of the Cartesian coordinate system of the electronic camera 6 is directed approximately perpendicularly and centrally to the reference frame 4 - the values of angles ak, cpk, Kk (defining the rotation of the electronic camera coordinate system XkykZk in the Cartesian coordinate system of the reference frame (x _r y _r z _r )) are calculated at the stage of the initial measurement (at time to) and the current measurement (at time ti).

Based on the images of reference signals 11 and controlled signals 12 recorded at the time, the following values are calculated (fig. 4): translation vectors: ¹ r (the vector of the displacement of the origin of the reference frame coordinate system (x _r y _r z _r ) from the origin of the electronic camera coordinate system (XkykZk)), ( ^{1 r} = [-145.00; -200.00; -95.00]) and * (the vector defining the displacement of the origin of the electronic camera coordinate system (XkykZk) from the origin of the measuring target coordinate system

Oyt Onr (xtytZt)) ( ¹ k = [118.07; -219.13; 62.03]). The rotation matrices are also calculated: ⁿ k (matrix describing the angular relationship between the electronic camera coordinate system (XkykZk) and the coordinate system

R^ ordinates of the reference frame (x _r yrZ _r )) and ⁿ k (matrix describing the angular relationship between the coordinate system of the electronic camera (XkykZk) and the coordinate system of the measuring target (xtytZt)).

« = 0.9999 0.0120 .-0.0072 -0.0120 0.9999 0.0096 0.0073 -0.0095 0.9999. 0.9999 -0.0120 0.0073 X = 0.0120 0.9999 -0.0095 .-0.0072 0.0096 0.9999.

Op

Based on the matrix, the values of the angles: ca, cpk, Kk are determined (formula 7), defining the rotation of the coordinate system of the electronic camera XkYkZk with respect to the coordinate system of the reference frame Onr Oni (x _r y _r z _r ) (ak = 0.544°, qk = 0.421°, Kk = 0.685°). Since both rotation matrices ⁿ k ^{and n} k are equal, the rotation angles: ca, φι, w (defining the rotation of the coordinate system of the measuring target XtytZt in the coordinate system of the reference frame (x _r y _r z _r )) are ca = 0.000°, φι = 0.000°, w = 0.000°.

PL 239 595 BI

This proves that the corresponding axes of the coordinate systems XkYkZk and x _r yrZ _r are mutually parallel. Using formula no. 5, the vector ¹ k (the offset of the origin of the electronic camera system (XkykZk) from the origin of the reference frame system (x _r y _r z _r )) is calculated:

°T^ = - °R ^r _k * °^ = [148.07; -199.13; 92.03].

Based on the calculation results, the components of vector ¹ 1 (defining the shift of the origin of the measuring disc coordinate system (xtytZt) from the origin of the reference frame coordinate system (x _r y _r z _r )) can be determined:

= [30.00; 20.00; 30.00],

The obtained calculation results confirmed the adopted assumptions regarding the positions of the reference frame 3, the measuring target 4, the electronic camera 6 and the fiber optic plumb line 14 at time to.

In a specific measurement cycle (during the current measurement t-ι), the values of the translation vectors k ( k = [148.07; -199.13; 92.03]) are calculated in a similar way (Fig. 5) on the recorded rotational speeds.

ItF Ipt Inr ik( ¹ k [113.52; -222.36; 60.95]) and rotation matrices: ⁿ ki based on which it determines

1.7 is the displacement of the measuring disc 4 relative to the reference frame 3 ( ¹ 1 = [31.12; 21.98; 33.06], and inr is the rotation matrix “t” (the matrix describing the angular relationship between the coordinate system of the measuring disc (x _t ytz _t ) and the coordinate system of the reference frame (x _r yrZ _r )).

¹ R^ =

0.9999

0.0131 .-0.0087

-0.0131 0.0087

0.9999 -0.0044

0.0045 1.0000.

inr

Based on the matrix “t, the rotation angles ca, φι, « (defining the rotation in time ti of the measuring target coordinate system XtytZt in the reference frame coordinate system 1 yr (x _r y _r z _r ) are determined (formula 7): ca = 0.250°, <a = 0.500°, w = 0.750°). The calculated values of the components of the vector ^J ti and the rotation angles ca, φι, κι in time ti are consistent with the assumed values adopted in this calculation example.

In the next step, the deflection of the measured object relative to the plumb line, realized by the z _p axis, of the Cartesian coordinate system x _P y _P z _p of the optical fiber plumb line 14 is determined. For this purpose, the results of photogrammetric measurements are analyzed, determining the position of the lower, luminous end of the optical fiber 21 (control point P) on the images recorded by the electronic camera of the plumb line 15. If the measurement results of the deflections of the optical fiber 14 are the same during the current measurement ti as during the initial measurement, then, at the level of measurement accuracy of this device, then the ΙβΡϋ time matrix P is a unit matrix and the optical fiber plumb line 14 demonstrates the stability of the position of the reference frame 3 (at the same time the reference element 2) during the current measurement ti (fig. 5).

In this case, the determined relative displacement of the measuring target 4 with respect to the reference frame 3 refers to the plumb line realized by the fibre-optic plumb line 14 (Fig. 5).

Example 2. The device for measuring displacements, as in Fig. 2, consists of a measuring target 4, attached by means of fastening screws 10 to the measuring element 1 of the measured object, and a reference frame 3, attached by means of fastening screws 10 to the reference element 2 of the measured object. In turn, a fibre-optic plumb line 14 is attached by means of coupling screws 9 to the reference frame 3, and an arm 5 is permanently attached thereto. The measuring target 4 has controlled signals 12 and has a defined Cartesian coordinate system of the measuring target XtytZt. On the other hand, the reference frame 3 has reference signals 11 and has a defined Cartesian coordinate system of the reference frame x _r yrZ _r , and the fibre-optic plumb line 14 has a defined Cartesian coordinate system of the fibre-optic plumb line x _P y _P z _p . Additionally, an electronic camera 6 is attached to the boom 5 with a coupling screw 9. The electronic camera 6 has its own Cartesian coordinate system XkykZk defined and is connected by a transmission cable 8 to the central data recording and processing system (CRPD) 7.

PL 239 595 Β1

The displacement measuring device, made as in example 2, is designed to measure the predicted displacements of elements 1 and 2 of the measured object in the range from 0.00 mm to 10.00 mm with a measurement accuracy of ±0.01 mm. The rotation of the elements of the measured object is determined at the level of thousandths of a degree. The displacement measurements performed are referred to the Cartesian coordinate system χ _Ρ γ _Ρ ζ _ρ of the fiber optic plumb line 14.

In this embodiment, the influence of environmental conditions is limited to a minimum. The size of the device (including the number and size of the controlled signals 12 and reference signals 11, as well as the method of setting the electronic camera 6 and its technical parameters) are selected after a thorough analysis of the case. The technical parameters of the electronic camera 6, including the size and resolution of the matrix and the lens used, should be selected so as to take into account the dimensions of the reference frame 3 and the dimensions of the used controlled signals 12 and reference signals 11. The recording of images with the electronic camera 6 and the vertical electronic camera 15 should be carried out under established lighting conditions.

Method of measuring displacements:

The measurement is carried out as in Example 1, with the boom 5 being permanently attached to the reference frame 3 (Fig. 2). The further procedure is as in Example 4.

Example 3. The arrangement as in Example 1, except that shown in Fig. 3, where the electronic camera 6 is placed at an independent observation station 13, unrelated to the measured object.

The displacement measuring device, made as in example 3, is designed to measure the predicted displacements of elements 1 and 2 of the measured object in the range from 0 mm to 200 mm with measurement accuracy in the range from hundredths of a millimeter to several millimeters. The accuracy obtained is determined by the technical parameters of the measuring equipment and the photographing distance. In this example of implementation, with significant photographing distances, the influence of environmental conditions on the measurement results must be taken into account using appropriate calculation procedures in CRPD 7.

Method of measuring displacements:

The method is the same as in example 1, i.e. the relative displacement of the measuring target 4 with respect to the reference frame 3 at time t2 is the same as at time ti ( ⁿ t — ⁿ t ), except that the electronic camera 6 is placed at the observation station 13, unrelated to the measured object (fig. 3), and the reference element 2 and the observation station 13 have undergone displacements with respect to the measuring element 1.

During the initial measurement at time to (fig. 4), and then the current measurement at time t2 (fig. 6), the electronic camera 6 records images of the reference frame 3 (with reference signals 11) and the measuring target 4 (with controlled signals 12) and the electronic camera of the plumb line 15 records images of the position of the end of the luminous optical fiber 21 (control point P) (fig. 3). If the reference element 2, represented by the reference frame 3, has been displaced, then there are significant differences in the results of photogrammetric measurements on the images recorded by the electronic camera of the plumb line 15, exceeding the assumed permissible values (fig. 6, time of the next measurement t2).

In the calculation example it was assumed that based on the results of photogrammetric measurements on images recorded with the electronic camera of the plumb line 15, the calculated angles of rotation of the fiber optic plumb line 14 are respectively: «ψ = -0.2565°, = -0.4967° and assuming that after calibration the coordinate axes x _p y _p of the _fiber optic plumb line 14 are parallel to the coordinate axes x _r y _r of the reference frame 3, then the angle Kp = 0.000°. Then the rotation matrix P , defining the position of the fiber optic plumb line 14 at time t2, and the matrix ⁿ r defining the position of the reference frame 3 relative to the plumb line, are equal to each other and amount to:

1.0000

0.0000

0.0087

0.0000 —0.0087

1.0000 0.0045

-0.0045 1.0000.

Based on the formulas known in the literature, the position of the measuring disc po2ηΡθ 4 relative to the vertical line is calculated, and the rotation matrix ⁿ r has the value:

PL 239 595 BI ^Z R

0.9999

0.0131 .-0.0001

-0.0131

0.9999

-0.0001

0.0001'

0.0001

1.0000.

2ηΡϋ

The angles of rotation of the measuring disc 4 with respect to the vertical line, obtained from the matrix t (formula 7), take the values: ca = -0.0065°, cpi = 0.0033° and w = 0.7522°, respectively. The angles of rotation of the reference frame 2nP0 with respect to the vertical line, obtained from the matrix ⁿ r (formula 7), take the values: ca = -0.2565°, cpr = -0.4967° and Kr = 0.0000°. The displacement vector of the measuring disc 4 with respect to the reference frame 3 Ργτ ( ¹ 1), determined in the Cartesian coordinate system χ _Ρ γ _Ρ ζ _ρ of the optical fiber plumb line 14, i.e. referred to the plumb line, is:

= [30.83; 22.13; 33.23]

The obtained calculation results confirmed the adopted assumptions regarding the position of the reference frame 3, the measuring target 4, the electronic camera 6 and the fiber optic plumb line 14 at time t2. The entire calculation process is performed in the CRPD 7 system, using appropriate algorithms.

List of symbols: 1 2 3 4 5 6 7 8 9

11 12

14

16 17 18 19

21 22 P d to ti t2

XrYrZ _r XtYtZt XkYkZk ΧρΥρΖρ ca, ψτ, Kr ca, φι, w

- measuring element

- reference item

- frame of reference

- measuring dial

- boom

- electronic camera

- Central Registration and Data Processing System (CRPD)

- camera transmission cable

- coupling screw

- mounting screw

- reference signal

- controlled signal

- observation post

- laser plummet

- vertical electronic camera

- transmission cable of the vertical electronic camera

- vertical support

- optical fiber suspension

- light source

- hole

- optical fiber

- weight

- checkpoint

- fiber optic length

- output measurement time

- current measurement time, with constant reference element

- time of the next current measurement, with the reference element tilted

- Cartesian coordinate system of the reference frame

- Cartesian coordinate system of the measuring disc

- Cartesian coordinate system of the electronic camera

- Cartesian coordinate system of the fiber optic plumb line

- three Euler angles defining the rotation of the coordinate system of the reference frame x _r yrZ _r

- three Euler angles defining the rotation of the coordinate system of the measuring disc XtytZt

PL 239 595 Β1

όφ, (φ, Αρ - three Euler angles defining the rotation of the laser plummet coordinate system χ _Ρ γ _Ρ ζ _ρ GX, q\, Tick - three Euler angles defining the rotation of the camera coordinate system o 50 >3 e*-1 electronic XkYkZk - rotation matrices describing the angular relationship between the coordinate system of the measuring disc (xtytZt) and the coordinate system of the reference frame (χ _Γ γ _Γ ζ _Γ ), respectively during the measurement: output Oyr l^r Ζγ’Γ in time to, current in time ti, current in time t2 - translation vectors defining the shift of the origin of the measuring target coordinate system (xtytZt) from the origin of the reference frame coordinate system (χ _Γ γ _Γ ζ _Γ ), respectively during the measurement: initial in time to, current in time ti, current in time θρί ipt 2nt ^K k' ^K k' ^K k olc 12 - rotation matrices describing the angular relationship between the coordinate system of the electronic camera (XkYkZk) and the coordinate system of the measuring target (xtytZt), respectively during the measurement: initial at time to, current at time ti, current at time io ł« O^tk^rt 2γΐ ¹ k' ¹ k' ¹ k olc 12 - translation vectors defining the shift of the origin of the electronic camera coordinate system (XkykZk) from the origin of the measuring target coordinate system (xtytZt), respectively during measurement: initial at time to, current at time ti, current at timeio 0 no ^. 1 D ^{r 2} D ^r ^k' ^K k' ^K k olc 12 - rotation matrices describing the angular relationship between the coordinate system of the electronic camera (XkykZk) and the coordinate system of the reference frame (x _r y _r z _r ), respectively during the measurement: initial at time to, current at time ti, current at time io Oyr Ιΐτ 2ψτ ¹ k' ¹ k' ^l k olc 12 - translation vectors defining the shift of the origin of the electronic camera coordinate system (XkYkZk) from the origin of the reference frame coordinate system (x _r y _r z _r ), respectively during the measurement: initial at time to, current at time ti, current at time io OnP InP 2nP ^K k' ^K k' ^K k olc 12 - rotation matrices describing the angular relationship between the coordinate system of the electronic camera (XkykZk) and the coordinate system of the laser plummet (x _p y _p z _p ), respectively during the measurement: initial at time to, current at time ti, current at time t2 OnP IpP 2pP λ _γ , Λ _Γ , n _r - rotation matrices describing the angular relationship between the coordinate system of the reference frame (x _r y _r z _r ) and the coordinate system of the laser plummet (x _p y _p z _p ), respectively during the measurement: initial at time to, current at time ti, current at time t2 OnPo IpPo 2 "Po ^K p , ^K p , ^K p - rotation matrix describing the angular dependence of the coordinate system of the optical fiber plumb line (x _p y _p z _p ) relative to the plumb line, respectively during the measurement: initial at time to, current at time ti, current at time t2 2 _R p ₀ - rotation matrix defining the angular dependence of the coordinate system of the measuring disc (xtytZt) with respect to the vertical line ² ^° ^ρ τί - rotation matrix defining the angular dependence of the coordinate system of the reference frame (x _r y _r z _r ) in relation to the plumb line - translation vector defining the shift of the origin of the coordinate system of the measuring target (xtytZt) in relation to the origin of the coordinate system of the reference frame (x _r y _r z _r ), determined in the Cartesian coordinate system of the laser plummet x _P y _P z _p , i.e. referred to the plumb line

PL 239 595 B1

Patent Claims

Claims (40)

Patent claims 1.A device for displacement measurements, comprising an electronic camera, connected to the central data recording and processing system (CRPD) and a vertical and photopoints recorded on the images, characterized by the fact that it includes a reference frame (3) with applied and at least four reference signals ( 11), which are embedded in one XrZr plane, in the local Cartesian coordinate system XryrZr, where if the number of reference signals (11) is m, then the number of reference signals (11) that cannot lie on one straight line is m- 1, and includes a target (4) with at least four controlled signals (12) embedded in one plane XtZt in the local Cartesian coordinate system XtytZt, where, if the number of controlled signals (12) is k, the number controlled signals (12), which cannot lie on one straight line, equals k-1, moreover, the electronic camera (6) has a defined Cartesian coordinate system XkykZk and p it is connected with the central data recording and processing system (7) and is facing the reference frame (3) and the measuring disc (4), moreover, a fiber optic plumb (14) is attached to the reference frame (3), which has in the lower part an electronic camera of the riser (15), connected to the central data recording and processing system (CRPD) (7) and the riser support (17), which in the middle of the upper part has an opening (20), in which with the use of a fiber optic sling (18), a light guide (21) of length d is suspended, the upper end of which is illuminated by a light source (19), the fiber optic riser (14) having a defined Cartesian coordinate system XpypZp. 2. The device according to claim The method of claim 1, characterized in that the central data recording and processing system (7) is a portable microcomputer. 3. The device according to claim The method of claim 1, characterized in that the reference signals (11) are in the form of squares. 4. The device according to claim 1 3. A method according to claim 3, characterized in that the squares are filled with white and / or black. 5. The device according to claim 1 The method of claim 1, characterized in that the reference signals (11) are in the form of concentric circles. 6. The device according to claim 1 The method of claim 1, characterized in that the reference signals (11) are in the form of a circle. 7. The device according to claim 1 The method of claim 1, characterized in that the reference signals (11) are in the form of a cross. 8. The device according to claim 1 The method of claim 1, characterized in that the reference signals (11) are in the form of a code sign. 9. The device according to claim 1 The device of claim 1, characterized in that the reference signals (11) are arranged on the reference frame (3) in a regular manner. 10. The device according to claim 1 The method of claim 1, characterized in that the monitored signals (12) have the form of squares. 11. The device according to claim 1 10. A method according to claim 10, characterized in that the squares are filled with white and / or black. 12. The device according to claim 1, 3. The method of claim 1, characterized in that the monitored signals (12) are in the form of concentric circles. 13. The device according to claim 1, 3. The method of claim 1, characterized in that the monitored signals (12) are in the form of a circle. 14. The device according to claim 1, The method of claim 1, characterized in that the monitored signals (12) are in the form of a cross. The device according to claim 1, The method of claim 1, characterized in that the monitored signals (12) have the form of a code sign. 16. The device according to claim 1, The method of claim 1, characterized in that the monitored signals (12) are arranged on the measuring disc (4) in a regular manner. 17. The device according to claim 1, The device of claim 1, characterized in that the device comprises a boom (5). 18. The device according to claim 1, 17, characterized in that the electronic camera (6) is removably connected to the arm (5) by means of a coupling screw (9). 19. The device according to claim 1 17, characterized in that the electronic camera (6) is permanently connected to the arm (5). PL 239 595 B1 20. The device according to claim 1 17, characterized in that the extension arm (5) is fastened to the reference element (2) by means of fastening screws (10) independently of the reference frame (3). 21. The device according to claim 1, 17, characterized in that the extension arm (5) is permanently attached to the reference frame (3). 22. The device of claim 1 17, characterized in that the boom (5) has the form of an L-shaped flat bar. 23. The device according to claim 1, The method of claim 1, characterized in that the electronic camera (6) is positioned on an observation station (13) not related to the measured object. 24. The device of claim 24 The device of claim 1, characterized in that the measuring disc (4) is located inside the reference frame (3). 25. The device according to claim 25 The method of claim 24, characterized in that the respective axes of the Cartesian coordinate systems of the measuring dial xtytzt and the reference frame Xryrzr are approximately parallel to each other in the output measurement. 26. The device according to claim 1, The device of claim 1, characterized in that the electronic camera (6) is connected wirelessly to the central data recording and processing system (7). The device of claim 27 The method of claim 1, characterized in that the axis yk of the Cartesian coordinate system of the electronic camera (6) is approximately perpendicular to the plane Xrzr defined by the Cartesian coordinate system of the reference frame (3). The device of claim 28 The method of claim 1, characterized in that the respective axes of the Cartesian coordinate systems: the Xkykzk electronic camera and the Xryrzr reference frame in the baseline measurement are approximately parallel to each other. 29. The device of claim 1 The device of claim 1, characterized in that the axis yk of the Cartesian coordinate system of the electronic camera (6) is approximately centered on the reference frame (3). 30. The device of claim 1 A device according to claim 1, characterized in that the reference frame (3) is in the form of a rectangular frame. 31. The device of claim 1 The device of claim 1, characterized in that the reference frame (3) is in the form of a rim. 32. The device of claim 32 A device according to claim 1, characterized in that the measuring disc (4) has the form of a rectangle. The device of claim 33. The device of claim 1, characterized in that the measuring disc (4) is in the form of a circle. 34. The device of claim 34 A device according to claim 1, characterized in that the light guide riser (14) is connected to the reference frame (3) in a detachable manner by means of coupling screws (9). 35. The device of claim 35 The method of claim 1, characterized in that the fiber optic riser (14) is permanently connected to the reference frame (3). The device of claim 36 The method of claim 1, characterized in that, after connecting the fiber optic riser (14) to the reference frame (3), the Cartesian coordinate systems of the Xryrzr reference frame and the fiber optic Xpypzp are parallel to each other. The device of claim 37. The method of claim 1, characterized in that the light guide (21) is a fiber optic. 38. The device of claim 38 The method of claim 37, characterized in that the fiber optic is an optical fiber with a circular cross section. 39. The device of claim 1 38, characterized in that the light guide (21) is a single fiber optic. 40. The device of claim 40 38, characterized in that the light guide (21) is a bundled fiber with a number of fibers greater than one.