Displacement measurement method and device suitable for reciprocating motion of non-planar targets

Abstract

The present invention discloses a displacement measurement method and device suitable for reciprocating motion of non-planar targets, belonging to the field of displacement measurement technology. The method comprises: binding a label paper with a triangular pattern to a target object, while making the reference side of the triangular pattern perpendicular to the movement direction of the label paper; fixing a camera, and setting an identification line perpendicular to the movement direction of the label paper in the shooting area of ​​the camera; obtaining a first conversion relationship between the pixel distance in the image shot by the camera and the actual space distance; obtaining a first ratio between the reference side of the triangular pattern and the corresponding height; moving the target object, so that the triangular pattern and the identification line intersect at two intersection points at the same time; based on the two intersection points, the first conversion relationship and the first ratio, calculating the shortest distance between the line segment formed by the two intersection points and the reference vertex; and determining the displacement of the target object based on the shortest distance obtained by moving the target object twice. The method of the present invention is applicable to measured objects with various geometric appearances.

Description

Technical Field

[0001] The present invention belongs to the technical field of displacement measurement, and in particular relates to a displacement measurement method and device suitable for reciprocating motion of a non-planar target. Background Art

[0002] Common methods for measuring target displacement on the market include visual measurement and non-visual measurement. The range of existing visual measurement solutions is limited by the camera's range. Different cameras are required for different ranges, and there is no universal solution. Furthermore, existing visual measurement solutions are only suitable for flat surface measurements and cannot adapt to irregular object displacements. Existing non-visual measurement solutions require binding the sensor to the object being measured. For retrofit projects, this often involves drilling holes in the surface of the object being measured, which in turn changes the object's strength. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a displacement measurement method and device suitable for the reciprocating motion of non-planar targets.

[0004] The present invention is achieved through the following technical solutions:

[0005] A first aspect of the present invention provides a displacement measurement method applicable to reciprocating motion of a non-planar target, comprising:

[0006] Obtain a label paper with a triangular pattern, and bind the label paper to the target object, while making the base side of the triangular pattern perpendicular to the movement direction of the label paper;

[0007] Fix the camera and set an identification line in the camera's shooting area, the identification line being perpendicular to the movement direction of the label paper;

[0008] Obtaining a pre-calibrated first conversion relationship, where the first conversion relationship is a conversion relationship between a pixel distance in an image captured by a camera and an actual spatial distance;

[0009] Obtaining a pre-calibrated first ratio, where the first ratio is the ratio between a reference side and a corresponding height of a triangular pattern on the label paper;

[0010] Move the target object so that the triangular pattern and the identification line intersect at two intersection points simultaneously;

[0011] Based on the two intersection points, the first conversion relationship and the first ratio, calculating the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern on the label paper;

[0012] The displacement of the target is determined based on the shortest distance obtained by moving the target twice.

[0013] Furthermore, when measuring the movement of a target object with a planar surface within a plane, the label paper is attached to the planar surface of the target object; when measuring the rotation of a target object with a curved surface that is a rectangle when unfolded along its axis, the label paper is attached to the curved surface of the target object.

[0014] Furthermore, the calibration method of the first conversion relationship includes:

[0015] Measuring the actual spatial distance between a first calibration line and a second calibration line, where the first calibration line and the second calibration line are two parallel line segments on the label paper;

[0016] Move the label paper so that the first marking line and the second marking line intersect with the identification line at the same time;

[0017] Calculating the pixel distance between the intersection of the first calibration line and the second calibration line with the identification line;

[0018] The first conversion relationship is calculated based on the actual spatial distance between the first calibration line and the second calibration line and the pixel distance between the intersections of the first calibration line and the second calibration line with the identification line.

[0019] Furthermore, the calibration method of the first ratio includes:

[0020] Measure the length of the reference side of the triangle pattern on the label paper;

[0021] Measure the vertical distance between the reference vertex and the reference side of the triangular pattern on the label paper. The reference vertex is the vertex in the triangular pattern opposite to the reference side.

[0022] The first ratio is calculated based on the length of the reference side of the triangular pattern and the perpendicular distance between the reference vertex and the reference side of the triangular pattern.

[0023] Furthermore, based on the two intersection points, the first conversion relationship, and the first ratio, calculating the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern on the label paper includes:

[0024] Calculate the pixel distance between two intersection points in the image captured by the camera;

[0025] Calculating the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship;

[0026] Based on the actual spatial distance between the two intersection points and the first ratio, the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern on the label paper is calculated.

[0027] Furthermore, the displacement of the target object is determined based on the shortest distance obtained by moving the target object twice, including:

[0028] The difference between the shortest distances obtained by moving the target twice is used to obtain the moving direction and distance of the target.

[0029] A second aspect of the present invention provides a displacement measurement device suitable for reciprocating motion of a non-planar target, comprising:

[0030] A label paper, used for binding to a target object, wherein the label paper is provided with a triangular pattern, and when the label paper is bound to the target object, a reference side of the triangular pattern is perpendicular to a movement direction of the label paper;

[0031] A camera is used to capture images, wherein a recognition line is provided in a capture area of ​​the camera, and the recognition line is perpendicular to a movement direction of the label paper;

[0032] a calibration module, configured to obtain a pre-calibrated first conversion relationship and a first ratio, wherein the first conversion relationship is a conversion relationship between a pixel distance in an image captured by a camera and an actual spatial distance, and the first ratio is a ratio between a reference side and a corresponding height of a triangular pattern on a label paper;

[0033] A first calculation module is configured to calculate, when the target object moves in a direction perpendicular to the reference side of the triangular pattern to a position where the other two sides of the triangular pattern simultaneously intersect the identification line at two intersection points, the shortest distance between a line segment formed by the two intersection points and a reference vertex of the triangular pattern on the label paper based on the two intersection points, the first conversion relationship, and the first ratio;

[0034] The second calculation module is used to determine the displacement of the target object based on the shortest distance obtained by moving the target object twice.

[0035] Furthermore, the calibration method of the first conversion relationship includes:

[0036] Measuring the actual spatial distance between a first calibration line and a second calibration line, where the first calibration line and the second calibration line are two parallel line segments on the label paper;

[0037] Move the label paper so that the first marking line and the second marking line intersect with the identification line at the same time;

[0038] Calculating the pixel distance between the intersection of the first calibration line and the second calibration line with the identification line;

[0039] The first conversion relationship is calculated based on the actual spatial distance between the first calibration line and the second calibration line and the pixel distance between the intersections of the first calibration line and the second calibration line with the identification line.

[0040] Furthermore, the calibration method of the first ratio includes:

[0041] Measure the length of the reference side of the triangle pattern on the label paper;

[0042] Measure the vertical distance between the reference vertex and the reference side of the triangular pattern on the label paper. The reference vertex is the vertex in the triangular pattern opposite to the reference side.

[0043] The first ratio is calculated based on the length of the reference side of the triangular pattern and the perpendicular distance between the reference vertex and the reference side of the triangular pattern.

[0044] Furthermore, the first calculation module is specifically configured to:

[0045] Calculate the pixel distance between two intersection points in the image captured by the camera;

[0046] Calculating the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship;

[0047] Based on the actual spatial distance between the two intersection points and the first ratio, the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern on the label paper is calculated.

[0048] Furthermore, the second calculation module is specifically configured to:

[0049] The difference between the shortest distances obtained by moving the target twice is used to obtain the moving direction and distance of the target.

[0050] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0051] (1) The method of the present invention is applicable to objects of various geometric appearances. It can measure not only the displacement of reciprocating motion of planar objects, but also the displacement of reciprocating motion of non-planar objects.

[0052] (2) The method of the present invention has the characteristics of low intrusion and no need for prefabrication. It does not need to be bound in advance like sensors. It is fully applicable even for renovation projects and does not change the strength of the object being measured.

[0053] (3) The present invention can calculate the lateral displacement through the longitudinal displacement. Even if the lateral displacement is large, as long as the longitudinal displacement is within the shooting range of the camera, the displacement length can be identified. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0055] Figure 1 A flow chart of the displacement measurement method of the present invention;

[0056] Figure 2 Schematic diagram of the label paper of the present invention;

[0057] Figure 3 A schematic diagram of calibrating the first conversion relationship and the first ratio in the present invention;

[0058] Figure 4 A schematic diagram of the intersection of a triangular pattern and an identification line in the present invention;

[0059] Figure 5 is another schematic diagram of the intersection of the triangular pattern and the identification line in the present invention;

[0060] In the figure, 1 is label paper, 2 is triangular pattern, 3 is identification line, 4 is shooting area, 5 is first calibration line, and 6 is second calibration line. DETAILED DESCRIPTION

[0061] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0062] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0063] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside" and the like indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0064] In the description of the present invention, unless otherwise expressly specified or limited, when the term "connection" or the like appears to indicate a connection relationship between components, such term should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be internal communication between two components or an interaction between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0065] like Figures 1 to 5 As shown, this embodiment discloses a displacement measurement method and device suitable for reciprocating motion of a non-planar target.

[0066] The first aspect of this embodiment discloses a displacement measurement method applicable to the reciprocating motion of a non-planar target, such as Figure 1 As shown, the displacement measurement method includes steps S100 to S700.

[0067] Step S100 . Obtain a label paper 1 with a triangular pattern 2 , and bind the label paper 1 to a target object, while making the reference side of the triangular pattern 2 perpendicular to the moving direction of the label paper 1 .

[0068] Specifically, a label sheet 1 is obtained, which has a triangular pattern 2 thereon. One side of the triangular pattern 2 is pre-determined as a reference side. The label sheet 1 is then attached to an object, and the label sheet 1 moves with the object, while ensuring that the reference side of the triangular pattern 2 is perpendicular to the direction of movement of the label sheet 1. For example, if the object is moving horizontally, the label sheet 1, after being attached to the object, will also move horizontally. In this case, the reference side of the triangular pattern 2 extends vertically.

[0069] In some implementations of this embodiment, when measuring the movement of an object with a planar surface within a plane, the label paper 1 is pasted on the planar surface of the object; when measuring the rotation of an object with a curved surface that is a rectangle when unfolded along its axis, the label paper 1 is pasted on the curved surface of the object.

[0070] The object having a curved surface that is a rectangle after unfolding specifically refers to an object having a curved surface on its surface, and the curved surface is a rectangle after unfolding.

[0071] For example, an object with a planar surface may be a rectangular parallelepiped, a cylinder, a truncated cone, or the like, and an object with a curved surface that is rectangular when unfolded may be a cylinder, a fan-shaped column, or the like.

[0072] In some implementations of this embodiment, the triangular pattern 2 is a right triangle, one right-angled side of the triangular pattern 2 is perpendicular to the moving direction of the label paper 1 , and the other right-angled side of the triangular pattern 2 is parallel to the moving direction of the label paper 1 .

[0073] In some implementations of this embodiment, the size of triangular pattern 2 is determined based on the size of the target object. If the triangular pattern 2 is too large, it may overlap itself, while if it is too small, accuracy may be low. For example, the triangular pattern 2 may be made as large as possible while avoiding overlapping itself, thereby improving recognition accuracy.

[0074] The label paper 1 can be in a rectangular structure or other shaped structures, and the label paper 1 is pasted on the target object at a position convenient for camera shooting.

[0075] Figure 2 A schematic diagram of a label paper 1 is given. The label paper 1 has a rectangular structure and moves horizontally. A triangular pattern 2 is provided on the label paper 1, and the left side of the triangular pattern 2 is its reference side. When the label paper 1 is moved horizontally, the other two sides of the triangular pattern 2 can simultaneously intersect with the identification line 3. Two horizontal calibration lines are provided on the label paper 1, marked as the first calibration line 5 and the second calibration line 6. By horizontally moving the label paper 1, the first calibration line 5 and the second calibration line 6 can simultaneously intersect with the identification line 3.

[0076] The colors of the three sides of the triangular pattern 2 are different from the colors of the label paper 1 and the target object, so that the three sides of the triangular pattern 2 can be accurately identified, thereby improving the accuracy of the measurement result.

[0077] Step S200 . Fix the camera and set an identification line 3 in the shooting area 4 of the camera. The identification line 3 is perpendicular to the moving direction of the label paper 1 .

[0078] Identification line 3 is a virtual line set in the camera. For example, if the camera resolution is 1920*1080, identification line 3 can be located at a position in the middle of the camera, such as an identification line with a vertical length of 600 pixels at a horizontal position of 1000. After each photo is taken, the calculation unit in the camera calculates the two intersection points on identification line 3 (the intersection points of identification line 3 and the two sides of triangle pattern 2 except the reference side), and then calculates the vertical length through the intersection points to obtain the intersection line of the virtual line and the real triangle.

[0079] The camera is fixed so that the camera can shoot a fixed area, that is, the shooting area 4 of the camera is fixed.

[0080] The length of the identification line 3 is greater than the length of the reference side of the triangular pattern 2, thereby ensuring that when the triangular pattern 2 passes through the identification line 3, both sides of the triangular pattern 2 except the reference side intersect with the identification line 3 at the same time, thereby ensuring the continuity of the target object displacement calculation.

[0081] Step S300: Obtain a pre-calibrated first conversion relationship, where the first conversion relationship is a conversion relationship between a pixel distance in an image captured by a camera and an actual space distance.

[0082] In some implementations of this embodiment, the calibration method of the first conversion relationship includes steps S310 to S340.

[0083] Step S310 : Measure the actual spatial distance between the first marking line 5 and the second marking line 6 , where the first marking line 5 and the second marking line 6 are two parallel line segments on the label paper 1 .

[0084] For example, when the movement direction of the label paper 1 is horizontal, the first marking line 5 and the second marking line 6 are two line segments extending in the horizontal direction, and the first marking line 5 is parallel to the second marking line 6 .

[0085] Step S320: Move the label paper 1 so that the first marking line 5 and the second marking line 6 intersect with the identification line 3 at the same time.

[0086] Step S330 : Calculate the pixel distances between the intersections of the first calibration line 5 and the second calibration line 6 with the identification line 3 .

[0087] Step S340 : Calculate a first conversion relationship based on the actual spatial distance between the first calibration line 5 and the second calibration line 6 and the pixel distance between the intersections of the first calibration line 5 and the second calibration line 6 and the identification line 3 .

[0088] Step S400: Obtain a pre-calibrated first ratio, where the first ratio is the ratio between a reference side and a corresponding height of the triangular pattern 2 on the label paper 1.

[0089] In some implementations of this embodiment, the calibration method of the first ratio includes steps S410 to S430.

[0090] Step S410 : Measure the reference side length of the triangular pattern 2 on the label paper 1 .

[0091] Step S420 : Measure the vertical distance between the reference vertex and the reference side of the triangular pattern 2 on the label paper 1 , where the reference vertex is the vertex in the triangular pattern 2 opposite to the reference side.

[0092] Step S430: Calculate a first ratio based on the length of the reference side of the triangle pattern 2 and the vertical distance between the reference vertex and the reference side of the triangle pattern 2.

[0093] For example, Figure 3 As shown, the triangular pattern 2 is composed of side ab, side ac and side bc, side ab is the reference side of the triangular pattern 2, point c is the reference vertex of the triangular pattern 2, line segment cd is the perpendicular line from point c to side ab, and line segment cd is perpendicular to side ab.

[0094] The process for calibrating the first conversion relationship is as follows: First, measure the vertical distance between the first and second calibration lines 5, 6. This vertical distance is the actual spatial distance between the first and second calibration lines 5, 6. Move the label paper 1 horizontally until the first and second calibration lines 5, 6 intersect the identification line 3 at points A and B, respectively. Calculate the pixel distance between points A and B in the image captured by the camera. The first conversion relationship is calculated based on the vertical distance between the first and second calibration lines 5, 6, and the pixel distance between points A and B.

[0095] For example, the vertical distance between the first calibration line 5 and the second calibration line 6 is 10 cm (centimeter), and the pixel distance between point A and point B is 100 pixels. Then the first conversion relationship is: pixel distance: actual space distance = 100 pixels: 10 cm.

[0096] The process of calibrating the first ratio is: measuring the lengths of the side ab and the line segment cd respectively, and the ratio of the lengths of the side ab to the line segment cd is the first ratio.

[0097] In this embodiment, the corresponding first conversion relationship and first ratio are calculated when the label paper 1 is in a flat state.

[0098] Step S500 : Move the target object so that the triangle pattern 2 and the identification line 3 intersect at two intersection points simultaneously.

[0099] Specifically, the target object is moved, and the label paper 1 on the target object moves with the target object. When the target object moves to a certain position, the triangular pattern 2 on the label paper 1 intersects with the identification line 3 at two intersection points at the same time.

[0100] Step S600 . Based on the two intersection points, the first conversion relationship and the first ratio, calculate the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern 2 on the label paper 1 .

[0101] The shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern 2 on the label paper 1 is the vertical distance from the reference vertex to the line segment formed by the two intersection points when the label paper 1 is in a plane.

[0102] In some implementations of this embodiment, based on the two intersection points, the first conversion relationship and the first ratio, the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern 2 on the label paper 1 is calculated, including steps S610 to S630.

[0103] Step S610: Calculate the pixel distance between two intersection points in the image captured by the camera.

[0104] Step S620: Calculate the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship.

[0105] Step S630 . Based on the actual spatial distance between the two intersection points and the first ratio, calculate the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern 2 on the label paper 1 .

[0106] Step S700: Determine the displacement of the target object based on the shortest distance obtained by moving the target object twice.

[0107] In some implementations of this embodiment, determining the displacement of the target object based on the shortest distance obtained by moving the target object twice includes: taking the difference between the shortest distances obtained by moving the target object twice to obtain the moving direction and moving distance of the target object.

[0108] The method of this embodiment is applicable to the detection of regular motions in which there is a corresponding conversion relationship between the displacement of the object and the label paper 1, such as the horizontal reciprocating movement of a flat plate, the rotation of a cylinder, etc.

[0109] like Figure 4 Figure 1 shows a schematic diagram of label paper 1 after a target object has moved once. The two hypotenuses of triangular pattern 2 intersect identification line 3 at points D and E, respectively. The pixel distance between points D and E in the image captured by the camera is calculated. Based on the pixel distance between points D and E and the first conversion relationship, the actual spatial distance between points D and E is calculated. Based on the actual spatial distance between points D and E and the first ratio, the shortest distance d1 between line segment DE and point c on label paper 1 is calculated.

[0110] like Figure 5 Figure 1 shows a schematic diagram of label paper 1 after the target object has moved again. The two hypotenuses of triangular pattern 2 intersect with identification line 3 at points F and G, respectively. The pixel distance between points F and G in the image captured by the camera is calculated. Based on the pixel distance between points F and G and the first conversion relationship, the actual spatial distance between points F and G is calculated. Based on the actual spatial distance between points F and G and the first ratio, the shortest distance d2 between line segment FG and point c on label paper 1 is calculated.

[0111] By taking the difference between the shortest distance d1 and the shortest distance d2, the direction and distance of the horizontal movement of the label paper 1 can be calculated. The displacement of the label paper 1 is the displacement of the target object.

[0112] For non-planar targets, such as cylinders, the angle of rotation of the cylinder can be measured. Specifically, a label paper 1 is evenly and horizontally covered on the surface of the cylinder, wherein the label paper 1 is provided with a triangular pattern 2, and the reference side of the triangular pattern 2 is perpendicular to the movement direction of the label paper 1; a camera is fixed, and an identification line 3 is set in the shooting area 4 of the camera, and the identification line 3 is perpendicular to the movement direction of the label paper 1; the conversion relationship between the pixel distance in the image captured by the camera and the actual space distance is calibrated as a first conversion relationship; the ratio between the reference side and the corresponding height of the triangular pattern 2 on the label paper 1 is calibrated as a first ratio; the cylinder is rotated, and then the label paper 1 is moved, so that the triangular pattern 2 and the identification line 3 intersect at two intersection points at the same time; based on the two intersection points, the first conversion relationship and the first ratio, the shortest distance between the line segment formed by the two intersection points and the vertex of the triangular pattern 2 on the label paper 1 is calculated; based on the shortest distance obtained by rotating the cylinder twice, the arc length of the rotation of the label paper 1 is calculated, and the rotation angle of the cylinder can be calculated according to the arc length and the cylinder.

[0113] A second aspect of this embodiment discloses a displacement measurement device for reciprocating motion of a non-planar target, wherein the displacement measurement device includes a label paper 1, a camera, a calibration module, a first calculation module, and a second calculation module.

[0114] A second aspect of the present invention provides a displacement measurement device suitable for reciprocating motion of a non-planar target, comprising:

[0115] The label paper 1 is used for binding on a target object. The label paper is provided with a triangular pattern 2. When the label paper 1 is bound on the target object, the reference side of the triangular pattern 2 is perpendicular to the movement direction of the label paper 1.

[0116] The camera is used to capture images. An identification line 3 is provided in the capturing area 4 of the camera. The identification line 3 is perpendicular to the moving direction of the label paper 1 .

[0117] The calibration module is used to obtain a pre-calibrated first conversion relationship and a first ratio. The first conversion relationship is the conversion relationship between the pixel distance in the image captured by the camera and the actual space distance. The first ratio is the ratio between the reference side and the corresponding height of the triangular pattern 2 on the label paper 1.

[0118] The first calculation module is used to calculate the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern 2 on the label paper 1 based on the two intersection points, the first conversion relationship and the first ratio when the target object moves in a direction perpendicular to the reference side of the triangular pattern 2 to a position where the other two sides of the triangular pattern 2 intersect with the identification line 3 at two intersection points.

[0119] The second calculation module is used to determine the displacement of the target object based on the shortest distance obtained by moving the target object twice.

[0120] In some embodiments of this embodiment, the calibration method of the first conversion relationship includes: measuring the actual spatial distance between the first calibration line 5 and the second calibration line 6, where the first calibration line 5 and the second calibration line 6 are two parallel line segments on the label paper 1; moving the label paper 1 so that the first calibration line 5 and the second calibration line 6 intersect with the identification line 3 at the same time; calculating the pixel distance between the intersection of the first calibration line 5 and the second calibration line 6 and the identification line 3; and calculating the first conversion relationship based on the actual spatial distance between the first calibration line 5 and the second calibration line 6 and the pixel distance between the intersection of the first calibration line 5 and the second calibration line 6 and the identification line 3.

[0121] Furthermore, the calibration method of the first ratio includes: measuring the length of the reference side of the triangular pattern 2 on the label paper 1; measuring the vertical distance between the reference vertex and the reference side of the triangular pattern 2 on the label paper 1, where the reference vertex is the vertex in the triangular pattern 2 opposite to the reference side; and calculating the first ratio based on the length of the reference side of the triangular pattern 2 and the vertical distance between the reference vertex and the reference side of the triangular pattern 2.

[0122] Furthermore, the first calculation module is specifically used to: calculate the pixel distance between two intersection points in the image captured by the camera; calculate the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship; calculate the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern 2 on the label paper 1 based on the actual spatial distance between the two intersection points and the first ratio.

[0123] In some implementations of this embodiment, the second calculation module is specifically configured to: calculate the difference between the shortest distances obtained by moving the target object twice to obtain the moving direction and moving distance of the target object.

[0124] It should be noted that those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working process of the system or device described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0125] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A displacement measurement method suitable for reciprocating motion of non-planar targets, characterized in that: include: Obtain a label paper with a triangular pattern, and bind the label paper to the target object, while making the base side of the triangular pattern perpendicular to the movement direction of the label paper; Fix the camera and set an identification line in the camera's shooting area, the identification line being perpendicular to the movement direction of the label paper; Obtaining a pre-calibrated first conversion relationship, where the first conversion relationship is a conversion relationship between a pixel distance in an image captured by a camera and an actual spatial distance; Obtaining a pre-calibrated first ratio, where the first ratio is the ratio between a reference side and a corresponding height of a triangular pattern on the label paper; Move the target object so that the triangular pattern and the identification line intersect at two intersection points simultaneously; Based on the two intersection points, the first conversion relationship and the first ratio, calculating the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangular pattern on the label paper; Determine the displacement of the target based on the shortest distance obtained by moving the target twice; The calibration method of the first conversion relationship includes: Measuring the actual spatial distance between a first calibration line and a second calibration line, where the first calibration line and the second calibration line are two parallel line segments on the label paper; Move the label paper so that the first marking line and the second marking line intersect with the identification line at the same time; Calculating the pixel distance between the intersection of the first calibration line and the second calibration line with the identification line; The first conversion relationship is calculated based on the actual spatial distance between the first calibration line and the second calibration line and the pixel distance between the intersections of the first calibration line and the second calibration line with the identification line.

2. The displacement measurement method applicable to reciprocating motion of non-planar targets according to claim 1, characterized in that: When measuring the movement of a target with a flat surface within a plane, the label paper is attached to the flat surface of the target; when measuring the rotation of a target with a curved surface that is a rectangle when unfolded along its axis, the label paper is attached to the curved surface of the target.

3. The displacement measurement method applicable to reciprocating motion of non-planar targets according to claim 1, characterized in that: The calibration method of the first ratio includes: Measure the length of the reference side of the triangle pattern on the label paper; Measure the vertical distance between the reference vertex and the reference side of the triangular pattern on the label paper. The reference vertex is the vertex in the triangular pattern opposite to the reference side. The first ratio is calculated based on the length of the reference side of the triangular pattern and the perpendicular distance between the reference vertex and the reference side of the triangular pattern.

4. The displacement measurement method applicable to reciprocating motion of non-planar targets according to claim 1, characterized in that: Calculating the shortest distance between a line segment formed by the two intersection points and a reference vertex of the triangular pattern on the label paper based on the two intersection points, the first conversion relationship, and the first ratio includes: Calculate the pixel distance between two intersection points in the image captured by the camera; Calculating the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship; Based on the actual spatial distance between the two intersection points and the first ratio, the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern on the label paper is calculated.

5. The displacement measurement method applicable to reciprocating motion of non-planar targets according to claim 1, characterized in that: Determine the displacement of the target based on the shortest distance obtained by moving the target twice, including: The difference between the shortest distances obtained by moving the target twice is used to obtain the moving direction and distance of the target.

6. A displacement measuring device suitable for reciprocating motion of non-planar targets, characterized in that: include: A label paper, used for binding to a target object, wherein the label paper is provided with a triangular pattern, and when the label paper is bound to the target object, a reference side of the triangular pattern is perpendicular to a movement direction of the label paper; A camera is used to capture images, wherein a recognition line is provided in a capture area of ​​the camera, and the recognition line is perpendicular to a movement direction of the label paper; a calibration module, configured to obtain a pre-calibrated first conversion relationship and a first ratio, wherein the first conversion relationship is a conversion relationship between a pixel distance in an image captured by a camera and an actual spatial distance, and the first ratio is a ratio between a reference side and a corresponding height of a triangular pattern on a label paper; A first calculation module is configured to calculate, when the target object moves in a direction perpendicular to the reference side of the triangular pattern to a position where the other two sides of the triangular pattern simultaneously intersect the identification line at two intersection points, the shortest distance between a line segment formed by the two intersection points and a reference vertex of the triangular pattern on the label paper based on the two intersection points, the first conversion relationship, and the first ratio; a second calculation module, configured to determine the displacement of the target object based on the shortest distance obtained by moving the target object twice; The calibration method of the first conversion relationship includes: Measuring the actual spatial distance between a first calibration line and a second calibration line, where the first calibration line and the second calibration line are two parallel line segments on the label paper; Move the label paper so that the first marking line and the second marking line intersect with the identification line at the same time; Calculating the pixel distance between the intersection of the first calibration line and the second calibration line with the identification line; The first conversion relationship is calculated based on the actual spatial distance between the first calibration line and the second calibration line and the pixel distance between the intersections of the first calibration line and the second calibration line with the identification line.

7. The displacement measuring device suitable for reciprocating motion of a non-planar target according to claim 6, characterized in that: The calibration method of the first ratio includes: Measure the length of the reference side of the triangle pattern on the label paper; Measure the vertical distance between the reference vertex and the reference side of the triangular pattern on the label paper. The reference vertex is the vertex in the triangular pattern opposite to the reference side. The first ratio is calculated based on the length of the reference side of the triangular pattern and the perpendicular distance between the reference vertex and the reference side of the triangular pattern.

8. The displacement measuring device suitable for reciprocating motion of a non-planar target according to claim 6, characterized in that: The first calculation module is specifically configured to: Calculate the pixel distance between two intersection points in the image captured by the camera; Calculating the actual spatial distance between the two intersection points based on the pixel distance between the two intersection points and the first conversion relationship; Based on the actual spatial distance between the two intersection points and the first ratio, the shortest distance between the line segment formed by the two intersection points and the reference vertex of the triangle pattern on the label paper is calculated.

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