Pose measuring device and pose measuring method based on laser rays

Abstract

The invention relates to the technical field of vision measurement, and provides a pose measurement device and method based on laser rays, and the device comprises at least three laser emitters, a laser receiving target surface and a data processing terminal. The laser receiving target surface is fixedly connected with a part of which the pose needs to be measured; the at least three laser emitters are used for emitting laser rays to the laser receiving target surface, and spots, falling on the laser receiving target surface, of the at least three laser rays are not on the same straight line; and the data processing terminal is in communication connection with the laser receiving target surface and the laser transmitter, and is used for obtaining the pose of the laser receiving target surface according to the coordinates of the spots in the laser receiving target surface and the flight time of the laser. According to the scheme, accurate pose information of the measuring device can be obtained, and errors of pipeline measurement and three-dimensional reconstruction are reduced.

Description

Technical Field

[0001] The present invention relates to the field of visual measurement technology, and in particular to a laser line-based posture measurement device and a posture measurement method. Background Art

[0002] With the progress and development of science and technology, pipelines are widely used in various fields, such as petroleum and chemical industries. During the use of pipelines, rust, cracks, bending and other defects may occur, which will threaten the safe operation of the system and have an adverse impact on economic activities. Therefore, it is necessary to measure the pipeline regularly.

[0003] Traditional pipeline measurement methods include ultrasonic detection, eddy current detection, magnetic field detection, etc. These methods use the physical properties of the pipeline to check for pipeline anomalies, but these methods cannot intuitively and quantitatively obtain the three-dimensional morphology of the inner surface of the pipeline.

[0004] At present, the commonly used method for pipeline measurement is photogrammetry based on structured light, such as laser triangulation. By combining the camera with structured light, the three-dimensional coordinates of the pipeline are obtained, and then the pipeline is reconstructed in three dimensions, and then the defects and parameter information of the pipeline are obtained.

[0005] Since the pipeline is relatively long, the laser triangulation method can only measure a cross section of the pipeline. Therefore, in order to obtain the coordinates of the entire pipeline, a set of walking mechanisms is required to measure while moving forward in the pipeline and determine the current position of the measuring device through the shaft encoder.

[0006] The shaft encoder can only determine the position of the device in the depth direction of the pipeline, and only obtains one degree of freedom. The remaining five degrees of freedom of the six degrees of freedom for determining the position and posture cannot be removed, and can only be assumed to have no changes, that is, it is assumed that the pipeline measurement device moves in a straight line without any eccentricity, deflection, and rotation changes. However, it is precisely because of rust, cracks, and bending that the pipeline needs to be measured. The pipeline measurement device cannot guarantee that other degrees of freedom will not change during movement. Therefore, the existing measurement method cannot obtain the position and posture of the measurement device itself, and the measurement results obtained are not accurate enough.

[0007] The Chinese patent publication number CN107063119A discloses a device and method for measuring the inner wall morphology and central axis straightness of a pipe. The patent decomposes posture changes, such as translation, pitch, yaw, and roll, and solves for each type. However, the actual posture of the target may have both translation and pitch, or both roll and yaw. When the target is not in a special posture, the patent cannot cope with it. The patent wants to calculate the posture of the laser probe by receiving the two-dimensional coordinates on the laser target, but the two-dimensional coordinates and the posture are not one-to-one corresponding, such as Figure 1As shown in the figure, one two-dimensional coordinate may correspond to multiple postures. Therefore, the posture calculated by this method may be wrong. A specific example is as follows: if two planes are mirror-symmetric in the vertical direction, the two-dimensional coordinates of the light spots on the two planes in the plane coordinate system are the same, so it is impossible to calculate a unique posture only through the two-dimensional coordinates on the plane.

[0008] Therefore, it is necessary to provide a laser line-based posture measurement device and posture measurement method to obtain accurate posture information of the measurement device and reduce errors in pipeline measurement and three-dimensional reconstruction.

[0009] The above information disclosed in the Background section is only for enhancement of understanding of the background of the present application and therefore it may contain information that does not constitute the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0010] The main purpose of the present invention is to overcome the problem that the position and posture of the measuring device itself cannot be obtained, and to provide a laser line-based position and posture measuring device and a position and posture measuring method to obtain accurate position and posture information of the measuring device and reduce errors in pipeline measurement and three-dimensional reconstruction.

[0011] To achieve the above-mentioned purpose, the first aspect of the present invention provides a laser line-based posture measurement device, comprising: at least three laser transmitters, a laser receiving target surface and a data processing terminal;

[0012] The laser receiving target surface is fixedly connected to the component whose posture needs to be measured; the laser receiving target surface is located in the pipeline;

[0013] At least three laser transmitters are used to emit parallel laser lines to the laser receiving target surface, and the spots where at least three laser lines fall on the laser receiving target surface are not on the same straight line;

[0014] The data processing terminal is communicatively connected with the laser receiving target surface and the laser transmitter, and is used to obtain the position and posture of the laser receiving target surface according to the coordinates of the spot in the laser receiving target surface and the flight time of the laser.

[0015] According to an exemplary embodiment of the present invention, there are three laser emitters, and the three laser emitters are three vertices of an isosceles right triangle or an equilateral triangle.

[0016] As a second aspect of the present invention, the present invention provides a laser line-based posture measurement method, using the laser line-based posture measurement device, comprising the following steps:

[0017] S1: The measuring trolley is fixedly connected to the laser receiving target surface; the measuring trolley and the laser receiving target surface are located in the pipeline;

[0018] S2: Record the coordinates of the initial state spot on the laser receiving target surface and the flight time of the laser;

[0019] S3: Measure the movement of the car, obtain the coordinates of the moving state spot on the laser receiving target surface and the flight time of the laser;

[0020] S4: The position and posture of the measuring vehicle are obtained according to the coordinates of the spots in the initial state and the moving state on the laser receiving target surface and the flight time of the laser.

[0021] According to an exemplary embodiment of the present invention, in step S1, the step of fixing the measuring vehicle to the laser receiving target surface includes:

[0022] Fix the laser receiving target surface at the front or rear of the measuring vehicle.

[0023] According to an exemplary embodiment of the present invention, in step S4, obtaining the position and posture of the measuring vehicle according to the coordinates of the spots in the initial state and the motion state on the laser receiving target surface and the flight time of the laser includes:

[0024] S41: establishing a target plane coordinate system and a laser coordinate system, wherein the target plane coordinate system includes an initial state target plane coordinate system and a moving state target plane coordinate system;

[0025] S42: Calculating the transformation relationship between the laser coordinate system and the initial state target plane coordinate system according to the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface;

[0026] S43: Calculating the transformation relationship between the laser coordinate system and the motion state target plane coordinate system according to the flight time of the motion state laser and the coordinates of the motion state spot on the laser receiving target surface;

[0027] S44: Calculate the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system according to the above two transformation relationships to obtain the position and posture of the measuring vehicle.

[0028] According to an exemplary embodiment of the present invention, in step S42, the transformation relationship between the laser coordinate system and the initial state target plane coordinate system is calculated based on the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface by combining the following equations:

[0029]

[0030] Among them, M 1 is the transformation matrix from the laser coordinate system to the initial target plane coordinate system, R 1 is the initial state rotation matrix, T 1is the initial state translation vector; (x, y, z) is the coordinate of a spot in the target plane coordinate system in the initial state; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system;

[0031] There are three spots in the initial state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the initial state target plane coordinate system.

[0032] According to an exemplary embodiment of the present invention, the Z coordinate in the initial state laser coordinate system is obtained according to the flight time of the initial state laser.

[0033] According to an exemplary embodiment of the present invention, in step S43, the transformation relationship between the laser coordinate system and the motion state target plane coordinate system is calculated based on the flight time of the motion state laser and the coordinates of the motion state spot on the laser receiving target surface by combining the following equations:

[0034]

[0035] Among them, M 2 is the transformation matrix from the laser coordinate system to the moving target plane coordinate system, R 2 is the motion state rotation matrix, T 2 is the motion state translation vector; (x', y', z') is the coordinate of the motion state spot in the target plane coordinate system; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system;

[0036] There are three spots in motion state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the motion state target plane coordinate system.

[0037] According to an exemplary embodiment of the present invention, the X coordinate and Y coordinate of the spot in the initial state in the laser coordinate system are respectively equal to the X coordinate and Y coordinate of the spot in the moving state in the laser coordinate system;

[0038] The Z coordinate in the moving state laser coordinate system is obtained according to the flight time of the moving state laser.

[0039] According to an exemplary embodiment of the present invention, in step S44, the calculation of the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system according to the above two transformation relationships to obtain the position and posture of the measuring vehicle includes:

[0040] The real-time rotation matrix and real-time translation vector are obtained according to the following equations, that is, the motion displacement of the measuring vehicle relative to the initial state is obtained:

[0041]

[0042] Where (x', y', z') is the coordinate of a spot in the moving state on the target plane coordinate system; (x, y, z) is the coordinate of the spot in the initial state on the target plane coordinate system; M is the coordinate transformation matrix, M = M 2 ×M 1 -1 , R is the real-time rotation matrix, T is the real-time translation vector;

[0043] The position and posture of the measuring trolley are obtained according to the initial position of the measuring trolley and the motion displacement of the measuring trolley relative to the initial state.

[0044] The advantages of the present invention are:

[0045] This solution only uses three laser transmitters and one laser receiving target plane. With a simple calculation method, the position and posture of the measuring device itself can be obtained in real time during pipeline measurement, and the pipeline reconstruction can be more accurate. Accurate measurement and reconstruction can also be performed when the measuring trolley rotates or is eccentric. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and other objects, features and advantages of the present application will become more apparent by describing in detail the exemplary embodiments thereof with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present application, and it is clear to a person skilled in the art that other accompanying drawings can be obtained from these accompanying drawings without creative effort.

[0047] Figure 1 The schematic diagram of the calculation process of the background technology patent is shown schematically.

[0048] Figure 2 The schematic diagram of the measuring pipeline of the measuring trolley is shown schematically.

[0049] Figure 3 The relationship between the spot and the laser receiving target surface is schematically shown.

[0050] Figure 4 The steps of the laser line based pose measurement method are schematically shown.

[0051] Figure 5 The steps of measuring the position and posture of the vehicle are schematically shown.

[0052] Figure 6 A schematic diagram of the coordinate system is shown schematically.

[0053] Among them, 1 is the data processing terminal, 2 is the data connection line, 3 is the laser transmitter, 4 is the laser line, 5 is the laser receiving target surface, 6 is the measuring trolley, and 7 is the pipeline wall. DETAILED DESCRIPTION

[0054] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0055] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0056] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0057] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0058] It should be understood that although the terms first, second, third, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another component. Therefore, the first component discussed below can be referred to as the second component without departing from the teachings of the concepts of the present application. As used herein, the term "and / or" includes any one of the associated listed items and all combinations of one or more.

[0059] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present application, and therefore cannot be used to limit the scope of protection of the present application.

[0060] According to a first specific embodiment of the present invention, the present invention provides a laser line based posture measurement device, such as Figure 2 As shown, it includes: at least three laser transmitters 3, a laser receiving target surface 5 and a data processing terminal 1; and also includes a data connection line 2.

[0061] The laser receiving target surface 5 is fixedly connected to the component whose position and posture need to be measured. The component whose position and posture need to be measured is a moving object, such as a measuring trolley. The laser receiving target surface 5 is located in the pipeline.

[0062] At least three laser emitters 3 are used to emit parallel laser lines 4 to the laser receiving target surface, and the spots of at least three laser lines 4 falling on the laser receiving target surface 5 are not on the same straight line. In order to obtain the position and posture of the measuring vehicle 6, the number of laser lines used can be greater than or equal to 3. As a preferred embodiment, Figure 3 As shown, there are three laser emitters 3, and the three laser emitters 3 are three vertices of an isosceles right triangle or an equilateral triangle.

[0063] The data processing terminal 1 is communicatively connected with the laser receiving target surface 5 and the laser transmitter 3 via a data connection line 2, and is used to obtain the position and posture of the laser receiving target surface 5 according to the coordinates of the spot in the laser receiving target surface 5 and the flight time of the laser. Since the laser receiving target surface 5 is fixedly connected to the component whose position and posture need to be measured, the position and posture of the laser receiving target surface 5 is the position and posture of the component whose position and posture need to be measured.

[0064] According to a second specific embodiment of the present invention, the present invention provides a laser line-based posture measurement method, using the laser line-based posture measurement device of the first specific embodiment, such as Figure 4 As shown, the following steps are included:

[0065] S1: The measuring trolley 6 is fixedly connected to the laser receiving target surface 5.

[0066] Fixedly connecting the measuring trolley 6 with the laser receiving target surface 5 includes: fixing the laser receiving target surface 5 at the front or rear of the measuring trolley 6. The laser receiving target surface 5 is perpendicular to the moving direction of the measuring trolley 6, and the laser line 4 emitted by the laser emitter 3 is parallel to the moving direction of the measuring trolley 6. The measuring trolley 6 and the laser receiving target surface 5 are located in the pipeline.

[0067] S2: Record the coordinates of the initial state spot on the laser receiving target surface and the flight time of the laser.

[0068] In the measurement preparation stage, the measuring trolley 6 is pushed into the pipeline entrance and the position is adjusted. The laser transmitter 3 emits the laser line 4, the laser receiving target surface 5 receives the laser line 4 and the data processing terminal 1 calculates the position of the spot on the target surface.

[0069] The flight time of the laser refers to the time it takes for the laser to be emitted from the laser emitter 3 to reach the laser receiving target surface 5 .

[0070] S3: Measure the movement of the car, obtain the coordinates of the moving state spot on the laser receiving target surface and the flight time of the laser.

[0071] The measuring car is constantly moving, and its position and posture can be calculated every time data is acquired, so the position and posture of the measuring car can be calculated in real time.

[0072] S4: The position and posture of the measuring vehicle are obtained according to the coordinates of the spots in the initial state and the moving state on the laser receiving target surface and the flight time of the laser.

[0073] like Figure 5 As shown, the position and posture of the measuring vehicle are obtained based on the coordinates of the spots in the initial state and the motion state on the laser receiving target surface and the flight time of the laser, including:

[0074] S41: Establish a target plane coordinate system and a laser coordinate system, wherein the target plane coordinate system includes an initial state target plane coordinate system and a moving state target plane coordinate system.

[0075] like Figure 6 As shown, the laser coordinate system is a coordinate system established with the laser emitter 3 as the reference. The laser emitter 3 is immobile, so the laser coordinate system is fixed from the initial state to the moving state. However, since the measuring trolley 6 is always moving in six degrees of freedom, it drives the laser receiving target surface 5 to move. The target plane coordinate system is a coordinate system established with the laser receiving target surface 5 as the reference. Since the laser receiving target surface 5 is moving, the target plane coordinate system moves from the initial state to the moving state and is not fixed.

[0076] Figure 6 In the figure, the laser coordinate system includes X-axis, Y-axis and Z-axis, wherein the Z-axis is parallel to the direction of the laser line 4. The black far point represents the laser emitter 3. Since the laser emitter 3 is fixed, the coordinates of the X-axis and Y-axis of the laser emitter remain unchanged. However, since the measuring trolley 6 moves, the distance from the laser emitter 3 to the laser receiving target surface 5 changes, so the coordinate of the Z-axis changes. Figure 6 Points A, B, and C represent the three spots in the initial state, and points A', B', and C' represent the spots corresponding to points A, B, and C in the moving state.

[0077] S42: Calculate the transformation relationship between the laser coordinate system and the initial state target plane coordinate system according to the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface.

[0078] Assume that the three points on the laser receiving target surface 5 are A, B, and C, and their coordinates in the target plane coordinate system are (x 1 ,y 1 ,0),(x 2 ,y 2 ,0),(x 3 ,y 3 ,0). In the laser coordinate system, the coordinates of the three points are (X 1, Y 1 , Z 1 ), (X 2 , Y 2 , Z 2 ), (X 3 , Y 3 , Z 3 ).

[0079] In the laser coordinate system, since the three laser emitters 3 are fixed, the X and Y coordinates of the three spots in the laser coordinate system are fixed, and the only variable is the Z coordinate, which is the distance from the spot to the laser emitter 3. The X and Y coordinates are determined by the placement of the laser emitter 3. For example, if the three laser emitters 3 are the three vertices of an equilateral triangle with a side length of a, then the coordinates of the three points in the laser coordinate system are (0,0,Z 1 ), (a,0,Z 2 ), If the three laser emitters 3 are an isosceles right triangle with a right angle side length of a, then the coordinates of the three points in the laser coordinate system are (0,0,Z 1 ), (a,0,Z 2 ), (0, a, Z 3 ).

[0081] According to the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface, the transformation relationship between the laser coordinate system and the initial state target plane coordinate system is calculated by combining the following equations:

[0082]

[0083] Among them, M 1 is the transformation matrix from the laser coordinate system to the initial target plane coordinate system, R 1 is the initial state rotation matrix, T 1 is the initial state translation vector; (x, y, z) is the coordinate of a spot in the target plane coordinate system in the initial state; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system;

[0084] There are three spots in the initial state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the initial state target plane coordinate system.

[0085] The Z coordinate in the initial state laser coordinate system is obtained by calculating the distance from the laser emitter 3 to the laser receiving target surface 5 according to the flight time of the initial state laser.

[0086] S43: Calculate the transformation relationship between the laser coordinate system and the motion state target plane coordinate system according to the flight time of the motion state laser and the coordinates of the motion state spot on the laser receiving target surface.

[0087] In the moving state, the three spots form three new points on the laser receiving target surface 5, and the coordinates of A', B', and C' on the updated target plane coordinate system are (x 1 ',y 1 ',0),(x 2 ',y 2 ',0),(x 3 ',y 3 ', 0), update the distances from the three spots to the laser emitter 3. In the case of an equilateral triangle, the coordinates of the three spots in the laser coordinate system are (0, 0, Z 1 ′), (a,0,Z 2 ′), Substitute the new coordinates into the transformation formula for calculation.

[0088] According to the flight time of the moving laser and the coordinates of the moving spot on the laser receiving target surface, the transformation relationship between the laser coordinate system and the moving target plane coordinate system is calculated by combining the following equations:

[0089]

[0090] Among them, M 2 is the transformation matrix from the laser coordinate system to the moving target plane coordinate system, R 2 is the motion state rotation matrix, T 2 is the motion state translation vector; (x', y', z') is the coordinate of the motion state spot in the target plane coordinate system; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system;

[0091] There are three spots in motion state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the motion state target plane coordinate system.

[0092] The X coordinate and Y coordinate of the spot in the initial state in the laser coordinate system are respectively equal to the X coordinate and Y coordinate of the spot in the moving state in the laser coordinate system.

[0093] The Z coordinate in the motion state laser coordinate system is obtained by calculating the distance from the laser transmitter 3 to the laser receiving target surface 5 according to the flight time of the motion state laser.

[0094] S44: Calculate the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system according to the above two transformation relationships to obtain the position and posture of the measuring vehicle.

[0095] According to the above two transformation relationships, the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system is calculated, and the position and posture of the measuring car are obtained, including:

[0096] Combining the above two transformation equations, we can get:

[0097]

[0098] The real-time rotation matrix and real-time translation vector are obtained according to the following equations, that is, the motion displacement of the measuring vehicle relative to the initial state is obtained:

[0099]

[0100] Where (x', y', z') is the coordinate of a spot in the moving state on the target plane coordinate system; (x, y, z) is the coordinate of the spot in the initial state on the target plane coordinate system; M is the coordinate transformation matrix, M = M 2 ×M 1 - 1 , R is the real-time rotation matrix, T is the real-time translation vector;

[0101] The position and posture of the measuring trolley are obtained according to the initial position of the measuring trolley and the motion displacement of the measuring trolley relative to the initial state.

[0102] First, the coordinate transformation matrix R and T are calculated, and then decomposed into angles in three directions and displacements in three directions, to obtain a total of 6 degrees of freedom information, plus the three-dimensional spatial information of the distance from the light spot to the laser emitter, which solves the problem that the patent CN107063119A cannot calculate a unique posture. At the same time, this application uses a parallel laser emitter with a laser receiving target to obtain the three-dimensional global coordinates of the target, which is simpler and more economical, and does not require a complex and expensive laser tracker.

[0103] When measuring the pipeline, the measuring trolley 6 will crawl from the mouth of the pipeline to the tail of the pipeline and measure each section of the pipeline. The measuring trolley 6 can measure the pipeline by laser triangulation, binocular or multi-eye measurement. Based on different measurement methods, different equipment can be carried on the measuring trolley 6. The data processing terminal 1 will determine the real-time position and posture of the measuring trolley 6 based on the received laser position, and reconstruct the entire pipeline in combination with the data captured by the measuring trolley 6.

[0104] The advantages of the present invention are:

[0105] This solution only uses three laser transmitters and one laser receiving target plane. With a simple calculation method, the position and posture of the measuring device itself can be obtained in real time during pipeline measurement, and the pipeline reconstruction can be more accurate. Accurate measurement and reconstruction can also be performed when the measuring trolley rotates or is eccentric.

[0106] The exemplary embodiments of the present invention are specifically shown and described above. It should be understood that the present invention is not limited to the detailed structure, configuration or implementation method described herein; on the contrary, the present invention is intended to cover various modifications and equivalent configurations included in the spirit and scope of the appended claims.

Claims

1. A laser line-based posture measurement device, characterized in that: include: At least three laser transmitters, a laser receiving target surface and a data processing terminal; The laser receiving target surface is fixedly connected to the component whose posture needs to be measured; the laser receiving target surface is located in the pipeline; At least three laser transmitters are used to emit parallel laser lines to the laser receiving target surface, and the spots where at least three laser lines fall on the laser receiving target surface are not on the same straight line; The data processing terminal is communicatively connected with the laser receiving target surface and the laser transmitter, and is used to obtain the position and posture of the laser receiving target surface according to the coordinates of the spot in the laser receiving target surface and the flight time of the laser.

2. The laser line-based posture measurement device according to claim 1, characterized in that: There are three laser emitters, and the three laser emitters are three vertices of an isosceles right triangle or an equilateral triangle.

3. A method for measuring a posture based on a laser line, using the apparatus for measuring a posture based on a laser line according to claim 1 or 2, characterized in that: The following steps are involved: S1: The measuring trolley is fixedly connected to the laser receiving target surface; the measuring trolley and the laser receiving target surface are located in the pipeline; S2: Record the coordinates of the initial state spot on the laser receiving target surface and the flight time of the laser; S3: Measure the movement of the car, obtain the coordinates of the moving state spot on the laser receiving target surface and the flight time of the laser; S4: The position and posture of the measuring vehicle are obtained according to the coordinates of the spots in the initial state and the moving state on the laser receiving target surface and the flight time of the laser.

4. The laser line-based posture measurement method according to claim 3, characterized in that: In step S1, the step of fixedly connecting the measuring vehicle to the laser receiving target surface includes: Fix the laser receiving target surface at the front or rear of the measuring vehicle.

5. The method for measuring the position and posture based on laser lines according to claim 3, characterized in that: In step S4, obtaining the position and posture of the measuring vehicle according to the coordinates of the spots in the initial state and the motion state on the laser receiving target surface and the flight time of the laser includes: S41: establishing a target plane coordinate system and a laser coordinate system, wherein the target plane coordinate system includes an initial state target plane coordinate system and a moving state target plane coordinate system; S42: Calculating the transformation relationship between the laser coordinate system and the initial state target plane coordinate system according to the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface; S43: Calculating the transformation relationship between the laser coordinate system and the motion state target plane coordinate system according to the flight time of the motion state laser and the coordinates of the motion state spot on the laser receiving target surface; S44: Calculate the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system according to the above two transformation relationships to obtain the position and posture of the measuring vehicle.

6. The laser line-based posture measurement method according to claim 5, characterized in that: In step S42, the transformation relationship between the laser coordinate system and the initial state target plane coordinate system is calculated based on the flight time of the initial state laser and the coordinates of the initial state spot on the laser receiving target surface by combining the following equations: Wherein, M1 is the transformation matrix from the laser coordinate system to the initial state target plane coordinate system, R1 is the initial state rotation matrix, T1 is the initial state translation vector; (x, y, z) is the coordinate of a spot in the initial state on the target plane coordinate system; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system; There are three spots in the initial state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the initial state target plane coordinate system.

7. The method for measuring the position and posture based on laser lines according to claim 6, characterized in that: The Z coordinate in the initial state laser coordinate system is obtained according to the flight time of the initial state laser.

8. The method for measuring position and posture based on laser lines according to claim 6, characterized in that: In step S43, the transformation relationship between the laser coordinate system and the motion state target plane coordinate system is calculated based on the laser flight time and the coordinates of the motion state spot on the laser receiving target surface by combining the following equations: Wherein, M2 is the transformation matrix from the laser coordinate system to the target plane coordinate system in motion state, R2 is the rotation matrix of motion state, T2 is the translation vector of motion state; (x', y', z') is the coordinate of a spot in motion state on the target plane coordinate system; (X, Y, Z) represents the coordinate of the spot in the laser coordinate system; There are three spots in motion state. The three equations are combined to obtain the transformation matrix from the laser coordinate system to the motion state target plane coordinate system.

9. The method for measuring the position and posture based on laser lines according to claim 8, characterized in that: The X coordinate and Y coordinate of the spot in the initial state in the laser coordinate system are respectively equal to the X coordinate and Y coordinate of the spot in the moving state in the laser coordinate system; The Z coordinate in the moving state laser coordinate system is obtained according to the flight time of the moving state laser.

10. The laser line-based posture measurement method according to claim 8, characterized in that: In step S44, the transformation relationship between the initial state target plane coordinate system and the moving state target plane coordinate system is calculated according to the above two transformation relationships to obtain the position and posture of the measuring vehicle, including: The real-time rotation matrix and real-time translation vector are obtained according to the following equations, that is, the motion displacement of the measuring vehicle relative to the initial state is obtained: Among them, (x', y', z') is the coordinate of the spot in the target plane coordinate system in the motion state; (x, y, z) are the coordinates of the spot in the target plane coordinate system in the initial state; M is the coordinate transformation matrix, M = M2×M1 -1 , R is the real-time rotation matrix, T is the real-time translation vector; The position and posture of the measuring trolley are obtained according to the initial position of the measuring trolley and the motion displacement of the measuring trolley relative to the initial state.

Images