CN117168298A - Remote laser positioning system - Google Patents
Remote laser positioning system Download PDFInfo
- Publication number
- CN117168298A CN117168298A CN202210575674.9A CN202210575674A CN117168298A CN 117168298 A CN117168298 A CN 117168298A CN 202210575674 A CN202210575674 A CN 202210575674A CN 117168298 A CN117168298 A CN 117168298A
- Authority
- CN
- China
- Prior art keywords
- laser
- screen
- image
- positioning system
- remote
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003384 imaging method Methods 0.000 claims abstract description 25
- 238000005259 measurement Methods 0.000 claims abstract description 23
- 239000004744 fabric Substances 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 239000005338 frosted glass Substances 0.000 claims 1
- 239000011159 matrix material Substances 0.000 description 37
- 238000000034 method Methods 0.000 description 16
- 238000004364 calculation method Methods 0.000 description 12
- 230000003287 optical effect Effects 0.000 description 11
- 238000013507 mapping Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 238000000605 extraction Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000013519 translation Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 3
- 239000005357 flat glass Substances 0.000 description 3
- 238000007781 pre-processing Methods 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 239000005337 ground glass Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009897 systematic effect Effects 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 238000009435 building construction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
The application provides a remote laser positioning system, comprising: a laser emitting device for emitting laser; and the laser receiving device is used for being arranged on the object to be measured, receiving the laser emitted by the laser emitting device and obtaining a facula image. Wherein, laser receiving arrangement includes: the screen is used for receiving the laser and imaging to obtain a facula image; the screen is arranged on one side of the mounting bracket; the image acquisition device is used for acquiring the facula image; and the processor determines the center coordinates of the light spots according to the light spot images so as to position the measured object. According to the remote laser positioning system provided by the embodiment of the application, an imageable screen is taken as a laser receiver, a camera shoots a screen which receives laser and forms a light spot to obtain a light spot image, and then the coordinates of the light spot center under a screen coordinate system are calculated from the light image to position an object. The positioning system has simple structure and high measurement accuracy.
Description
Technical Field
The application relates to the technical field of detection, in particular to a remote laser positioning system.
Background
In the process of large-scale building construction, in order to ensure the shape accuracy of construction, such as straightness, verticality and the like, auxiliary tools such as plumb lines and the like are often used as references, and then simple tools such as rules and the like are used for estimating. This method has disadvantages of complicated operation, low measurement accuracy, and the like, although it is low in cost. In construction situations where accuracy is required, such as in the installation of high-rise elevators, in order to ensure accuracy, an experienced operator is required to repeatedly debug to set the plumb line. When the high-rise elevator guide rail verticality is measured, the high-rise elevator guide rail verticality is limited by a tool, the verticality measurement is carried out by setting a verticality line every few meters, the operation is complicated, the measurement accuracy is limited by the stability of the vertical line, and a large amount of station splicing errors are introduced to be measured, so that the whole verticality of the guide rail cannot be obtained.
Chinese patent application CN112539713a discloses a device and method for detecting straightness of small-caliber barrel. The device uses a laser generator to emit laser, receives optical signals by a PSD (photoelectric position sensor), and obtains straightness through signal processing. Although the device has the characteristics of simplicity and compactness, the device is limited by the characteristics of small PSD receiving area (the effective receiving area of PSD produced by a known PSD producer is only a few millimeters to tens of millimeters), sensitivity to light incidence angle and small required light spot, and laser diverges along with the increase of transmission distance, so that the PSD positioning mode is difficult to be applied to long-distance laser positioning.
Disclosure of Invention
In view of the above, the present application provides a remote laser positioning system that is simple, compact, has high measurement accuracy, and can be applied to remote laser positioning.
The application also provides a well measuring system with the remote laser positioning system.
In order to solve the technical problems, the application adopts the following technical scheme:
a remote laser positioning system according to an embodiment of the first aspect of the present application includes:
a laser emitting device for emitting laser;
a laser receiving device which is arranged on the object to be measured and receives the laser emitted by the laser emitting device and obtains a facula image,
wherein the laser receiving device comprises:
the screen is used for receiving the laser and forming light spots;
the screen is arranged on one side of the mounting bracket;
the image acquisition device is used for acquiring an image comprising the light spots to obtain light spot images;
and the processor determines the spot center coordinates according to the spot images, and positions the measured object by locating the spot center coordinates of the spot images obtained by locating the laser receiving device at different positions of the measured object.
Further, the laser emitting device includes:
a laser generator;
the laser direction adjusting bracket is used for adjusting the laser direction emitted by the laser generator.
Further, the light spot emitted by the laser generator is a light spot with a central symmetrical shape.
Further, the laser pointing adjustment bracket includes:
the laser generator is arranged on the supporting plate;
the supporting legs are arranged on the bottom surface of the supporting plate in a height-adjustable mode, and the supporting legs are correspondingly arranged on the periphery of the laser generator at intervals.
Still further, the backup pad is equilateral triangle, laser generator sets up in the center department of backup pad, the supporting legs includes three, three the supporting legs is threaded connection respectively on the three angles of backup pad.
Further, the screen comprises an opaque imaging layer and a light-transmitting layer, wherein the light-transmitting layer is located on the side far away from the image acquisition device.
Further, the imaging layer is any one selected from rear projection film, rear projection cloth, rear projection hard screen and ground glass, and the light-transmitting layer is a hard light-transmitting layer.
Still further, the mounting bracket includes a reference portion and a screen mounting portion, the reference portion and the screen mounting portion are perpendicular to each other, the reference portion is plate-shaped for being placed on the object to be measured, the screen mounting portion includes a right angle portion and the screen is mounted on the screen mounting portion.
Still further, the mounting bracket further includes an image pickup device mounting portion, the image pickup device mounting portion being parallel to the screen mounting portion, the image pickup device being disposed at the image pickup device mounting portion such that the image pickup device faces the imaging layer.
Still further, the image capturing device includes a lens and a camera, the center of the lens is aligned with the center of the screen, and the field of view of the camera covers the entire screen.
Still further, the remote laser positioning system further comprises:
the calibration plate is provided with a plurality of marks which are uniformly distributed and have regular patterns with preset intervals.
A hoistway measurement system according to an embodiment of a second aspect of the present application includes:
two sets of remote laser positioning systems according to the above embodiments, wherein the two sets of remote laser positioning systems are arranged in parallel;
and the section measuring device is arranged in parallel with the two laser receiving devices.
Further, the hoistway measurement system further includes:
and the height sensor is arranged corresponding to the section measuring device and used for determining the well height at the section measured by the section measuring device.
Further, the hoistway measurement system further includes:
and the inclination angle sensor is arranged corresponding to the section measuring device and used for determining the inclination angle of the section measured by the section measuring device relative to the horizontal plane.
The technical scheme of the application has at least one of the following beneficial effects:
according to the remote laser positioning system provided by the embodiment of the application, the imageable screen is taken as the laser receiver, the camera shoots the screen which receives laser and forms the light spot to obtain the light spot image, then the coordinate of the light spot center under the screen coordinate system is calculated from the light image, namely the relative position of the light spot center relative to the screen sideline is calculated, so that the vertical offset of the laser receiving device relative to the laser optical axis is measured, and the object is positioned relative to the vertical direction of the laser optical axis.
Drawings
FIG. 1 is a schematic diagram of a remote laser positioning system according to an embodiment of the present application, wherein (a) shows a top view and (b) shows a side view;
FIG. 2 is a schematic top view of a laser emitting device in a remote laser positioning system according to an embodiment of the present application;
FIG. 3 is a schematic rear view of a laser receiver in a remote laser positioning system according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a remote laser positioning system according to an embodiment of the present application, in which the center of a focal spot is in the screen coordinate system used during positioning;
FIG. 5 is a schematic diagram of a laser positioning system according to an embodiment of the present application for positioning rail straightness;
fig. 6 is a schematic diagram of a hoistway measurement system according to the present application;
FIG. 7 is a flow chart of a positioning method according to an embodiment of the application;
FIG. 8 is a schematic diagram showing the relationship between the screen coordinate system and the calibration coordinate system.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. It will be apparent that the described embodiments are some, but not all, embodiments of the application. All other embodiments, which are obtained by a person skilled in the art based on the described embodiments of the application, fall within the scope of protection of the application.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate a relative positional relationship, which changes accordingly when the absolute position of the object to be described changes.
A remote laser positioning system and a positioning method using the same according to an embodiment of the present application are described in detail below with reference to fig. 1 to 8.
First, a tele-laser positioning system according to an embodiment of the present application will be described in detail with reference to fig. 1-6.
As shown in fig. 1, the remote laser positioning system according to the embodiment of the present application includes a laser emitting device 10, a laser receiving device 20, and a processor (not shown).
Wherein the laser emitting device 10 is used for emitting laser light.
The laser receiving device 20 is used for being arranged on an object to be measured and receiving laser emitted by the laser emitting device 10 and obtaining a spot image. Specifically, the laser light receiving device 20 includes: a screen 21, a mounting bracket 22, and an image capture device 23. The screen 21 is for receiving the laser light and forming a spot. The screen 21 is provided at one side of the mounting bracket 22. The image acquisition means 23 is used for acquiring an image comprising said light spot, obtaining a light spot image. That is, the image pickup device 23 picks up an image including a flare on the screen 21 to form a flare image. And the processor determines the center coordinates of the light spots according to the light spot images so as to position the measured object.
According to the remote laser positioning system of the embodiment of the application, the laser is received by the imageable screen 21, the screen 21 which receives the laser and forms the light spot is shot by the image acquisition device 23 to obtain a light spot image, and then the coordinates of the light spot center under the screen coordinate system are calculated from the light spot image, that is, the relative position of the light spot center relative to the screen sideline is calculated, so that the offset of the vertical direction of the laser receiving device 20 relative to the laser optical axis is measured, and the object is positioned relative to the vertical direction of the laser optical axis. The laser positioning system has simple structure and high measurement precision, and can be widely used for measuring the straightness of the guide rail and positioning various objects moving along the optical axis in the direction vertical to the optical axis.
Further, as shown in fig. 1 to 2, the laser emitting device 10 includes: a laser generator 11 and a laser pointing adjustment bracket 12. The laser generator 11 is a component that emits laser light as its name implies. The laser generator 11 is disposed on the laser direction adjusting bracket 12, and the laser direction emitted by the laser generator 11 is adjusted by the laser direction adjusting bracket 12. Thus, by adjusting the laser pointing adjustment bracket 12, the laser pointing can be adjusted conveniently.
Preferably, the laser generator 11 emits a laser beam having a spot with a central symmetrical shape, i.e. a spot with a circular spot, i.e. the optical axis thereof is located. The core spot of the laser spot gradually increases with increasing emission distance. In order to ensure that the spot can fall completely on the screen 21 of the receiver (let the screen width be b) while ensuring the lateral measurement range a, the maximum spot diameter within the measured range is required to be smaller than the product of the safety scaling factor k and (b-a). The safety ratio coefficient k is required to be larger than 1, and the recommended range is 1.2-2.
Further, as shown in fig. 1-2, the laser pointing adjustment support 12 includes: a support plate 121 and a plurality of support feet 122. The laser generator 11 is disposed on the support plate 121, a plurality of support legs 122 are disposed on the bottom surface of the support plate 121 with adjustable height, and the plurality of support legs 122 are disposed on the periphery of the laser generator 121 at intervals. The support legs 122 are provided correspondingly on the outer periphery of the laser generator 11, that is to say, on the projection view in the vertical direction, on the outside of the laser generator 11. Thus, by adjusting the support legs 122 at different positions, respectively, the optical axis of the laser light emitted from the laser generator 11 can be extended in a predetermined direction, for example, a horizontal direction or a vertical direction.
According to an embodiment of the present application, as shown in fig. 2, the support plate 121 is formed, for example, in an equilateral triangle shape, the laser generator 11 is disposed at the center of the support plate 121, the support legs 122 include three, and the three support legs 122 are respectively screwed on three corners of the support plate 121. The support leg 122 of the threaded connection is not only simple in structure, but also continuously adjustable in height. In addition, by arranging one supporting leg 122 on each of the three corners of the equilateral triangle, the laser generator 11 is positioned at the center of the equilateral triangle, and the structure is simple and easy to adjust, and the adjusting efficiency is high.
Further, the screen 21 may for example comprise an opaque imaging layer (i.e. the layer where the laser imaging forms the spot) and a light transmitting layer, wherein the light transmitting layer is located at the side remote from the image acquisition device 23. That is, the light transmitting layer faces the laser generator 11 so that the laser light passes through the light transmitting layer and finally forms a spot on the imaging layer on the side close to the image pickup device. In view of the spot image to be acquired by the image acquisition device 23, it is preferable to have the imaging layer on the side close to the image acquisition device in order to reduce noise and ensure imaging accuracy. Meanwhile, in order to ensure light transmission efficiency, it is preferable that the other dielectric layers except the imaging layer in the screen 21 have high light transmittance. In addition, in view of the fact that the flatness of the imaging layer may cause an imaging distance error when photographing the image pickup device, it is preferable that the higher the flatness of the imaging layer of the screen 21 is, the better. In practice, products such as rear projection films, rear projection cloths, rear projection hard screens, ground glass and the like can be used as imaging layers of the screens, and the light-transmitting layer can be a hard light-transmitting layer, such as a flat glass layer, a hard light-transmitting resin material layer and the like. Among them, for soft rear projection film, rear projection cloth (as imaging layer), it can be attached on high light transmittance flat glass (as light transmitting layer) to form screen 21 together with flat glass to ensure the flatness of screen 21. In addition, the screen 21 size may be determined in relation to the span according to the screen size, the spot size, and the like described above.
In addition, as shown in fig. 5, the mounting bracket 22 includes a reference portion 222 and a screen mounting portion 221, the reference portion 222 is perpendicular to the screen mounting portion 221, the reference portion 222 is flat-plate-shaped for being placed on the object to be measured (that is, the surface of the object to be measured is adhered by the reference portion 222), the screen mounting portion 221 includes a right-angle portion (with the inner edge line of which a screen coordinate system can be determined) such as a rectangular frame (as shown in fig. 3 to 4), and the screen 21 is mounted on the screen mounting portion 221. In the present application, a specific coordinate of the spot center in a screen coordinate system is determined by establishing the screen coordinate system, which is a coordinate system, with the imaging surface of the screen 21, thereby positioning the object to be measured. For this reason, as shown in fig. 3 to 4, the screen mounting portion 221 is preferably formed as a rectangular frame so that the edges of the screen mounting portion can be directly extracted from the spot image, respectively as XY axes of the screen coordinate system. And extracting the side line of the rectangular part based on the light spot image, so as to establish a screen coordinate system. In addition, the screen mounting portion 221 may take other shapes, such as a right triangle or the like.
Of course, this is only one way, and it is also possible to set (e.g. by printing, etc.) coordinate axes directly on the imaging layer of the screen, for example. At this time, in order to secure the mounting accuracy of the screen 21, alignment marks may be formed on the screen 21 and the screen mounting portion 221, respectively, so that systematic errors caused by mounting errors may be avoided.
Further, as shown in fig. 5, the mounting bracket 22 may further include an image pickup device mounting portion 223. The image pickup device mounting portion 223 is parallel to the screen mounting portion 221, and the image pickup device 23 is disposed at the image pickup device mounting portion 223 such that the image pickup device 23 faces the imaging layer of the screen 21.
Further, the image capturing device 23 includes a lens (not shown) whose center is aligned with the center of the screen 21 and a camera (not shown) whose field of view covers the entire screen 21. Therefore, the light spot image containing the screen edge can be obtained, and the coordinates of the light spot center can be conveniently and accurately estimated.
Further, the remote laser positioning system can further comprise a calibration plate, and a plurality of marks which are uniformly distributed and have regular patterns with preset intervals are arranged on the calibration plate. For example, zhang Zhengyou calibration plates, i.e., checkerboard calibration plates, may be employed. Therefore, the imaging surface (namely the imaging layer of the screen) can be calibrated to obtain the external parameter matrix of the camera; in addition, a plurality of pictures with different angles can be shot by using the calibration plate so as to calibrate the internal reference matrix and distortion parameters of the camera.
The remote laser positioning system according to the embodiment of the application can be used singly in a group, for example, for measuring the fluctuation amount of the measured object in the direction of the vertical optical axis, such as straightness and the like. In addition, the two or more groups can be matched for use.
First, a case where 1 set thereof is used alone for measuring the straightness of the guide rail 100 will be described with reference to fig. 5.
As shown in fig. 5, a laser generator 10 is installed at one end of the rail under test 100 so that laser light is emitted parallel to the rail under test 11. A laser receiving device 20 is installed at the other end of the rail 100 to be tested. The reference portion 222, which is a positioning reference surface of the mounting bracket 22, is attached to the surface to be measured of the rail 100 to be measured. The laser light receiving device 20 is moved along the measured orbit 100, receives the laser light at different positions from the laser light generating device 10 and calculates coordinates of the corresponding light spots falling on the screen 21 at the different positions, thereby calculating the fluctuation amount of the screen 21 perpendicular to the optical axis direction at the different positions, that is, the fluctuation amount perpendicular to the measured orbit, that is, the straightness of the measured orbit.
In addition, two groups can be matched for use.
A hoistway measurement system according to a second aspect of an embodiment of the present application, as shown in fig. 6, includes: two sets of tele-laser positioning systems according to the above embodiments, and a section measuring device 30.
Wherein, two groups of the remote laser positioning systems are arranged in parallel. That is, as shown in fig. 6, the laser light generating devices 10 in the 2 groups are arranged side by side and correspond to the respective laser light receiving devices 20. The section measuring device 30 is arranged in parallel with the two laser receiving devices.
As shown in fig. 6, two sets of remote laser positioning systems are assembled with the section measuring device 30 into a whole, so that the transverse position (including transverse translation and rotation) of the section measuring device 30 is positioned, the section measuring device 30 measures section data at different heights of the hoistway are transversely aligned, the straightness and the torsion of the hoistway wall are obtained, and the effective collimation accommodating space of the hoistway, namely the cross section size of a cube which can be inscribed in the hoistway, is calculated.
Further, the hoistway measurement system may further include: a height sensor (not shown). The height sensor is provided in correspondence with the section measuring device 30 for determining the hoistway height at the section measured by the section measuring device 30. Thus, the height data obtained by the height sensor and the section data obtained by the section measuring device 30 are combined to obtain a 3D model of the hoistway.
Further, the hoistway measurement system may further include: and an inclination sensor 40. The inclination sensor 40 is provided in correspondence with the section measuring device 30 for determining the inclination of the section measured by the section measuring device 30 with respect to the horizontal plane. Thus, in the case where the horizontal measurement section cannot be ensured, the horizontal inclination of the measurement section can be obtained by adding the inclination sensor 40 to ensure the accuracy of the measurement data.
Next, a specific method for positioning by using the remote laser positioning system according to the embodiment of the present application will be described.
The method for positioning by using the remote laser positioning system according to the embodiment of the application, as shown in fig. 7, includes the following steps:
s1, placing the mounting bracket on a tested object.
That is, first, the laser light receiving device 10 is set on the object to be measured, specifically, the mounting bracket 22 in the laser light receiving device 10 is set with the reference portion 222 thereof on the object to be measured.
S2, calibrating the screen by using a calibration plate, and determining an internal parameter matrix, distortion parameters, an external parameter matrix of the camera, and a mapping relation between a screen coordinate system and a calibration plate coordinate system, wherein the external parameter matrix is an external parameter matrix of the screen on the camera, the screen coordinate system is a coordinate system determined based on a side line of the screen, the calibration plate coordinate system is a coordinate system determined based on the calibration plate, and the calibration plate is provided with a plurality of marks which are uniformly distributed and have a preset value in a pattern rule.
In general, an image obtained by photographing with a camera is a pixel, and specific size information of a real object cannot be directly reflected. If it is desired to reflect the specific size information of the real object, the pixel coordinates (u, v) need to be converted to coordinates (x, y) in the image coordinate system (OXY) coordinate system, and thereafter further converted to coordinates in the geographic coordinate system. As the geographical coordinate system, there is also a calibration coordinate system (O 1 X 1 Y 1 ) I.e. calibrating the imaging plane by means of a calibration plate and determining the coordinate system at the time of external reference, and the screen coordinate system (O 2 X 2 Y 2 )。
That is, first, it is necessary to convert the pixel coordinates into image coordinates, thereafter convert the image coordinates into calibration coordinate system coordinates, and finally convert the calibration coordinate system coordinates into screen coordinate system coordinates.
The pixel coordinates and the image coordinates can be converted by an internal reference matrix.
The undistorted image coordinates and the calibration coordinate system coordinates can be converted through an off-screen parameter matrix.
The coordinate of the calibration coordinate system and the coordinate of the screen coordinate system can be converted based on the mapping relation of the coordinate system and the coordinate of the screen coordinate system.
The internal reference matrix and distortion parameters of the camera are determined by parameters of the camera, and can be obtained directly by a manufacturer or can be obtained by a Zhang Zhengyou calibration method.
For example, by the camera focal length (i.e. f x ，f y ) Offset from the center point (c) x ，c y ) To determine the reference matrix a of the camera.
Namely: internal reference matrix
There is a certain correspondence between the pixel coordinates and the image coordinates, that is, the pixel coordinates are the product of the internal reference matrix and the image coordinates. If the camera is distorted, the effect of the distortion also needs to be taken into account.
The image itself is 2-dimensional information, so that the z-direction is eliminated by normalizing the equation set f (1), and the normalized image coordinates are (x ', y').
Then, according to the distortion parameters, the radial and tangential distortions of the camera body can be fitted by the equation set f (2):
after that, a correspondence relation between the pixel coordinates and the distorted image coordinates is established:
that is, pixel coordinates may be converted to distorted image coordinates (x ", y") based on the camera's internal reference matrix a.
However, in converting the distorted image coordinates to calibration plate coordinates, it is necessary to perform de-distortion, that is, to perform coordinate conversion in the de-distorted image.
As an example, based on the distortion parameters and the internal reference matrix of the camera, the distortion correction can be performed on the image through an opencv-undidistor function, an undidistor points function, and the like, so as to obtain an undistorted image, and therefore, the pixel coordinates in the undistorted image can be combined with the internal reference matrix to obtain ideal undistorted image coordinates (x, y).
The opencv-undististor function, undististor points function are known to those skilled in the art, and are not the application, and detailed description thereof is omitted here.
The world coordinate of a point in the calibration plate is (X 1 ,Y 1 ,Z 1 ) The ideal image coordinates without distortion are (x, y, z), and the two can rotate the matrix R and 3*1 through 3*3 to translate the vector T, and the corresponding relationship is shown in the following f (4):
wherein Z is taken as "0" and since the size information of the image in the calibration plate is known (i.e. the world coordinate of a point is (X 1 ,Y 1 ,Z 1 ) Known) and from the above, the ideal undistorted image coordinates (x, y) are determined, whereby the off-screen parameter matrix B, i.e. the matrix in the above formula f (4), can be determined by the above formula f (4): b= [ r|t ]']. When the calibration plate is positioned on the imaging surface of the screen, the camera external parameter matrix under the current world coordinate system is the external parameter matrix of the screen on the camera, and is called as the external parameter matrix of the screen for short.
Thus, the off-screen parameter matrix is determined by the calibration plate. And in a specific measurement process, the calibration plate can be replaced by a screen through the off-screen parameter matrix, and the coordinates of the spot center in the spot image under the calibration coordinate system can be calculated based on the off-screen parameter matrix and also based on the formula f (4).
From the above, after the image coordinates are converted into the calibration coordinate system coordinates by the off-screen parameter matrix, it is also necessary to further convert them into the screen coordinate system coordinates.
Next, the mapping relation between the calibration coordinate system and the screen coordinate system is described with reference to fig. 8.
As shown in fig. 8, the calibration coordinate system (O 1 X 1 Y 1 ) By calibrating the point O in the plate 1 A coordinate system established for the origin of the coordinate axis, and a screen coordinate system established by the point O on the screen 2 And a coordinate system is established for the origin of the coordinate axis. Illustratively, according to one embodiment of the present application, the screen coordinate system has two inner edges of the mounting portion 222 of the mounting bracket 22, which are shown on the image, as XY axes, respectively, and has an intersection point O thereof 2 Is the origin of the coordinate axes, thereby establishing a screen coordinate system O 2 X 2 Y 2 . As can be seen from the above analysis in combination with fig. 7, to determine the coordinates of the spot center in the screen coordinate system, it is necessary to first determine the calibration coordinate system (O 1 X 1 Y 1 ) Mapping relation with the screen coordinate system.
After the calibration plate image is taken by replacing the screen with the calibration plate, X in the calibration coordinate system can be extracted from the image (shown in figure 7) after the de-distortion change treatment 1 Y 1 Shaft and origin O 1 At the same time, X of a screen coordinate system can be extracted 2 Y 2 Origin O 2 Thereby, X can be calculated 1 Axis and X 2 The angle between the axes and the corresponding translation vector can likewise be calculated as Y 1 Axis and Y 2 The angle between the axes and the corresponding translation vector, from which O can be determined 1 X 1 Y 1 With O 2 X 2 Y 2 Mapping relation between the two. In practice, the mapping relationship may be characterized by a rotational translation matrix.
The above describes the use of a calibration plate to determine the camera's internal reference matrix, distortion parameters, the off-screen reference matrix, and the mapping between the screen coordinate system and the calibration plate coordinate system. Therefore, the calibration of the whole camera is completed, and after the screen is installed in place in specific use, the coordinates of the center of the light spot can be calculated based on the light spot image and the calibration result.
And S3, enabling the laser emitting device to emit laser so as to form a light spot on the screen.
That is, in a specific positioning measurement process, the laser emitting device is first caused to emit laser light to form a laser spot on the screen.
Specifically, for example, the laser emitting device is placed at a reference point, any position of the surface to be measured of the object to be measured may be used as the reference point, and the value measured thereafter is the fluctuation amount with respect to the reference point.
After placement, the support legs 122 are adjusted so that the emitted laser light axis is facing the screen.
S4, shooting the light spots through the camera to obtain the light spot images.
That is, after forming a spot on a screen, a spot image is obtained by photographing with a camera. Here, the flare image is an image including a border of the screen.
S5, determining the spot center based on the spot image.
Specifically, according to some embodiments of the present application, the step S5 may include:
s51, carrying out image recognition on the facula image, and extracting the facula outline.
That is, the spot profile is first extracted by image recognition.
As can be seen from the above description in step S2, the shape of the spot is affected by the camera distortion, thereby affecting the subsequent overall calculation accuracy. To this end, according to some embodiments of the present application, the spot image is first subjected to distortion correction by an internal reference matrix and distortion parameters of the camera to obtain an undistorted spot image, and a spot profile is extracted based on the undistorted spot image. According to some embodiments of the application, regarding the extraction of the spot profile, it may comprise:
preprocessing the facula image to remove noise points and obtain a preprocessed image;
and extracting the light spot contour from the preprocessed image through a contour extraction algorithm.
By performing the preprocessing, the subsequent calculation amount can be reduced, and the calculation accuracy can be improved.
Specifically, the preprocessing the flare image to remove noise points, and obtaining a preprocessed image may include:
first, the flare image is converted into a gray scale. For example, the image may be converted into a gray scale image by gray scale processing or color channel separation, so that the calculation speed may be increased and the calculation amount may be reduced.
The gray scale map is then filtered by neutral filtering. Through filtering processing, noise can be effectively removed. And the processing efficiency and the processing precision are improved.
And finally, roughly calculating the center of the light spot by using a gravity center method for the gray level image after filtering, and intercepting the area where the light spot is positioned according to the size of the light spot to obtain the preprocessed image. Therefore, the method is beneficial to reducing the calculation time and the occupation of the memory of the processor.
Further, regarding extracting the spot profile, for example, a profile extraction algorithm such as canny may be used to extract the spot profile. As for the contour extraction algorithm, an existing method may be adopted, and the comparison of the present application is not particularly limited, and a detailed description thereof will be omitted herein.
S52, performing circle fitting on the extracted light spot outline to obtain a fitting light spot area.
According to some embodiments of the application, the step S52 may include:
extracting a facula contour from the preprocessed image;
for the light spot contour, performing primary circle fitting by using a Hough transform method to obtain a primary fitting center and a primary estimated radius;
determining the radius of the light spot according to the diameter ratio of the diffraction light ring to the central light spot and the preliminary estimated radius;
the preliminary fitting center is taken as a center, and a fitting area is defined by the light spot radius;
and in the fitting area, carrying out multiple circle fitting on the points based on gray values in the gray value range of the light spot edge, wherein the average position of the center obtained by the multiple circle fitting is taken as the light spot center.
Therefore, the average position of the center obtained by multiple circle fitting is used as the light spot center, so that the calculation accuracy can be further improved, and the systematic error caused by fitting errors can be reduced.
S6, determining the coordinates of the light spot center in a calibration coordinate system through the internal parameter matrix, the distortion parameters and the external screen parameter matrix based on the light spot center.
That is, after the spot center is determined through the above step S5, the coordinates of the spot center in the calibration coordinate system are next determined according to the internal parameter matrix, the distortion parameter, and the off-screen parameter matrix determined in the previous step S2.
According to some embodiments of the application, the step S6 may include:
and determining undistorted spot pixel coordinates of the undistorted spot center based on the spot center determined by the undistorted spot image.
And calculating the coordinates of the spot center in the calibration coordinate system based on undistorted spot pixel coordinates, an internal reference matrix and the external screen reference matrix. More specifically, first, obtaining undistorted facula image coordinates based on undistorted facula pixel coordinates and an internal reference matrix; and calculating the coordinates of the spot center in the calibration coordinate system based on the undistorted spot image coordinates and the off-screen parameter matrix.
The specific calculation process refers to the description of the step S2, and the corresponding calculation is performed. A detailed description thereof will be omitted herein.
And S7, determining the coordinates of the light spot center in the screen coordinate system based on the coordinates of the light spot center in the calibration coordinate system and the mapping relation between the screen coordinate system and the calibration plate coordinate system.
That is, after obtaining the coordinates of the spot center in the calibration coordinate system, the coordinates of the spot center in the screen coordinate system may be obtained by converting the mapping relationship obtained in step S2.
For the specific calculation, the same reference to the description in step S2 may be used to perform the correlation calculation. A detailed description thereof will be omitted herein.
The above description describes the positioning of the measurement point when the laser light receiving device 20 is disposed on the object to be measured.
By this calculation, the straightness of the object to be measured can be measured. At this time, the method further comprises the following steps:
s8, respectively calculating the spot center coordinates of spot images obtained by the laser receiving device at different positions of the measured object;
s9, determining the straightness of the measured object according to the spot center coordinates of the spot images obtained at different positions.
That is, by moving the laser light receiving device 20 on the surface to be measured of the object to be measured, the straightness of the object to be measured can be determined from the difference between the center coordinates of the spot at different positions.
While the foregoing is directed to the preferred embodiments of the present application, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present application, and such modifications and adaptations are intended to be comprehended within the scope of the present application.
Claims (14)
1. A remote laser positioning system, comprising:
a laser emitting device for emitting laser;
a laser receiving device which is arranged on the object to be measured and receives the laser emitted by the laser emitting device and forms an obtained facula image,
wherein the laser receiving device comprises:
the screen is used for receiving the laser and forming light spots;
the screen is arranged on one side of the mounting bracket;
the image acquisition device is used for acquiring an image comprising the light spots to obtain light spot images;
and the processor determines the center coordinates of the light spots according to the light spot images so as to position the measured object.
2. The remote laser positioning system of claim 1 wherein the laser emitting device comprises:
a laser generator;
the laser direction adjusting bracket is used for adjusting the laser direction emitted by the laser generator.
3. The remote laser positioning system of claim 2 wherein the spot emitted by the laser generator is a centrally symmetric shaped spot.
4. The remote laser positioning system of claim 2, wherein the laser pointing adjustment mount comprises:
the laser generator is arranged on the supporting plate;
the supporting legs are arranged on the bottom surface of the supporting plate in a height-adjustable mode, and the supporting legs are correspondingly arranged on the periphery of the laser generator at intervals.
5. The remote laser positioning system of claim 4 wherein the support plate is equilateral triangle, the laser generator is disposed at the center of the support plate, the support legs comprise three, and the three support legs are threaded onto three corners of the support plate, respectively.
6. The remote laser positioning system of claim 1 wherein the screen includes an opaque imaging layer and a light transmissive layer, wherein the light transmissive layer is located on a side remote from the image acquisition device.
7. The remote laser positioning system of claim 6 wherein the imaging layer is any one selected from the group consisting of rear projection film, rear projection cloth, rear projection hard screen, frosted glass, and the light transmissive layer is a rigid light transmissive layer.
8. The remote laser positioning system of claim 6, wherein the mounting bracket includes a reference portion and a screen mounting portion, the reference portion and the screen mounting portion being perpendicular to each other, the reference portion being in a flat plate shape for placement on a test object, the screen mounting portion including a right angle portion and the screen being mounted on the screen mounting portion.
9. The remote laser positioning system of claim 8, wherein the mounting bracket further comprises an image capture device mount, the image capture device mount being parallel to the screen mount, the image capture device being disposed at the image capture device mount such that the image capture device faces the imaging layer.
10. The remote laser positioning system of claim 9 wherein the image acquisition device comprises a lens and a camera, the center of the lens being aligned with the center of the screen, the field of view of the camera covering the entire screen.
11. The remote laser positioning system of claim 1, further comprising:
the calibration plate is provided with a plurality of marks which are uniformly distributed and have regular patterns with preset intervals.
12. A hoistway measurement system, comprising:
the two sets of tele-laser positioning systems of any one of claims 1 to 11, wherein the two sets of tele-laser positioning systems are arranged side-by-side in parallel;
and the section measuring device is arranged in parallel with the two laser receiving devices.
13. The hoistway measurement system of claim 12, further comprising:
and the height sensor is arranged corresponding to the section measuring device and used for determining the well height at the section measured by the section measuring device.
14. The hoistway measurement system of claim 13, further comprising:
and the inclination angle sensor is arranged corresponding to the section measuring device and used for determining the inclination angle of the section measured by the section measuring device relative to the horizontal plane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210575674.9A CN117168298A (en) | 2022-05-25 | 2022-05-25 | Remote laser positioning system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210575674.9A CN117168298A (en) | 2022-05-25 | 2022-05-25 | Remote laser positioning system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117168298A true CN117168298A (en) | 2023-12-05 |
Family
ID=88936202
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210575674.9A Pending CN117168298A (en) | 2022-05-25 | 2022-05-25 | Remote laser positioning system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117168298A (en) |
-
2022
- 2022-05-25 CN CN202210575674.9A patent/CN117168298A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9644960B2 (en) | Laser beam horizontal trueness testing device and corresponding method | |
| US7177740B1 (en) | Method and apparatus for dynamic measuring three-dimensional parameters of tire with laser vision | |
| JP3197529B2 (en) | Non-contact measurement method of wheel alignment characteristics and its measurement device | |
| CN1155799C (en) | Laser linear scanning three-dimensional measurement double liquid knife virtual grid mapping calibrating method and equipment | |
| CN105486235B (en) | A kind of goal-griven metric method in ball machine video pictures | |
| CN102087483B (en) | Optical system for focal plane detection in projection lithography | |
| CN110501026B (en) | Camera internal orientation element calibration device and method based on array star points | |
| CN103676487B (en) | A kind of workpiece height measurement mechanism and bearing calibration thereof | |
| CN110966956A (en) | Binocular vision-based three-dimensional detection device and method | |
| CN111457942B (en) | Plane height-fixing calibration device | |
| CN107345789A (en) | A kind of pcb board hole location detecting device and method | |
| JP2008517283A (en) | Improved measurement system | |
| CN113048957A (en) | Vision-based rapid detection system for precision of laser demarcation device | |
| CN110260889B (en) | Automatic calibrating device and method for handheld range finder | |
| CN101726316A (en) | Element of interior orientation and distortion tester | |
| CN112665523B (en) | Combined measurement method for complex profile | |
| CN109506562A (en) | A kind of Binocular vision photogrammetry device for the detection of solar wing spreading lock depth | |
| CN107436131A (en) | The measurement of planeness system and its measuring method of a kind of laser alignment equipment | |
| CN108195568A (en) | Upper beam illumination testing apparatus centering self-test and calibration method | |
| CN117168298A (en) | Remote laser positioning system | |
| CN117168297A (en) | Positioning method using remote laser positioning system | |
| CN201277864Y (en) | Inner orientation element and distortion test instrument | |
| US11640680B2 (en) | Imaging system and a method of calibrating an image system | |
| JP3629314B2 (en) | How to determine the angle of inclination of a coded leveling gutter | |
| CN210154537U (en) | Metal structure deformation measuring device based on digital photography |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |