A measuring method and a video measuring instrument

Abstract

The application relates to a measurement method and an image measuring instrument. The method comprises the following steps: determining that a standard block is in the ranging range of a target laser ranging device; measuring, by the target laser ranging device, a plurality of position points on the standard block opposite to the target laser ranging device in the process that a control platform moves according to a preset moving path; determining first three-dimensional coordinates of the standard block based on the plurality of position points; controlling the control platform to move so that the standard block is in the imaging range of an imaging device; collecting, by the imaging device, an image comprising the standard block; determining second three-dimensional coordinates of the standard block based on the image; and determining the relative position between the imaging device and the target laser ranging device based on the first three-dimensional coordinates and the second three-dimensional coordinates to further determine the position of at least one laser ranging device in the image measuring instrument. The method can accurately determine the position of at least one laser ranging device in the image measuring instrument.

Description

Technical Field

[0001] This application relates to the field of measurement technology, and in particular to a measurement method and an image measuring instrument. Background Technology

[0002] With the rapid development of measurement technology, image measuring instruments have emerged. An image measuring instrument is a device that can precisely measure the surface dimensions, contours, angles and positions, geometric tolerances, and other parameters of various complex parts.

[0003] A vision measuring instrument typically includes a laser rangefinder, a camera lens, and a movable stage. To measure the geometric features of a workpiece, the stage needs to be moved to obtain parameters of the workpiece in the X, Y, and Z axes to determine its geometric characteristics. To meet different measurement scenarios, vision measuring instruments capable of using at least one laser rangefinder have emerged. For such instruments to accurately measure the geometric features of the workpiece, the position of at least one laser rangefinder must be correctly reflected in the same coordinate system. Summary of the Invention

[0004] Therefore, it is necessary to provide a measurement method and an image measuring instrument that can accurately determine the position of at least one laser ranging device in an image measuring instrument, in order to address the above-mentioned technical problems.

[0005] Firstly, this application provides a measurement method applied to an image measuring instrument. The image measuring instrument includes a movable stage, a camera device, and at least one laser rangefinder. The camera device and the laser rangefinder are respectively arranged opposite to the stage. A standard sample block is placed on the stage.

[0006] The standard sample block is determined to be within the ranging range of the target laser ranging device, which is any one of at least one laser ranging device.

[0007] During the movement of the control platform along the preset path, multiple position points on the standard sample block that are opposite to the target laser rangefinder are measured by the target laser rangefinder.

[0008] The first three-dimensional coordinates of the standard sample block are determined based on multiple location points.

[0009] Control the stage to move so that the standard sample is within the camera's field of view;

[0010] Images, including standard sample blocks, are acquired using a camera device;

[0011] Based on the image, determine the second three-dimensional coordinates of the standard sample block;

[0012] Based on the first three-dimensional coordinates and the second three-dimensional coordinates, the relative position between the camera device and the target laser rangefinder is determined.

[0013] The position of at least one laser rangefinder in the image measuring instrument is determined based on the relative position between the camera device and the target laser rangefinder.

[0014] Secondly, this application also provides an image measuring instrument, which includes a movable platform, a camera device, and at least one laser rangefinder device, the camera device and the laser rangefinder device being respectively disposed opposite to the platform, a memory, and a processor. The memory stores a computer program, and the processor executes the computer program to implement some or all of the steps described in any method of the first aspect of the embodiments of this application.

[0015] The aforementioned measurement method and image measuring instrument determine that the standard sample block is within the ranging range of the target laser ranging device, which is any one of at least one laser ranging device. During the movement of the control platform along a preset path, multiple position points on the standard sample block relative to the target laser ranging device are measured using the target laser ranging device. Based on these multiple position points, the first three-dimensional coordinates of the standard sample block are determined. The control platform is moved to place the standard sample block within the imaging range of the camera device. An image including the standard sample block is acquired using the camera device. Based on the image, the second three-dimensional coordinates of the standard sample block are determined. Based on the first and second three-dimensional coordinates, the relative position between the camera device and the target laser ranging device is determined. Based on the relative position between the camera device and the target laser ranging device, the position of at least one laser ranging device in the image measuring instrument is determined. Using the measurement method provided in this embodiment, the relative position between the camera device and each laser ranging device can be accurately determined with the assistance of the standard sample block, thereby accurately determining the position of at least one laser ranging device in the image measuring instrument. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an image measuring instrument provided in an embodiment of this application;

[0018] Figure 2 for Figure 1 A magnified view of the dashed frame AA section of the image measuring instrument;

[0019] Figure 3 A schematic flowchart of a measurement method provided in an embodiment of this application;

[0020] Figure 4 This is a schematic diagram of the structure of a standard sample block provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] Figure 1 This is a schematic diagram of the structure of an image measuring instrument provided in an embodiment of this application. The measurement method provided in this embodiment can be applied to, for example... Figure 1 The image measuring instrument 1 shown. Figure 2 for Figure 1 A magnified view of the dashed frame AA section of the image measuring instrument, combined with... Figure 1 as well as Figure 2 As can be seen, the image measuring instrument 1 includes a movable platform 12, a camera device 22, and at least one laser rangefinder 24 (it should be noted that...). Figure 2 Only one laser rangefinder 24 is shown in the image. The camera and the laser rangefinder are respectively set opposite to the platform, and a standard sample block is placed on the platform.

[0023] Figure 3 This is a flowchart illustrating a measurement method provided in an embodiment of this application. In one exemplary embodiment, such as... Figure 3 As shown, a measurement method is provided, which is applied to, for example Figure 1 In the image measuring instrument shown, the method includes steps 302 to 316. Wherein:

[0024] Step 302: Determine that the standard sample block is within the ranging range of the target laser ranging device, wherein the target laser ranging device is any one of at least one laser ranging device.

[0025] Among them, the image measuring instrument is a precision measuring instrument that can extract the planar features, straight line features, point features or other geometric features of the workpiece and calculate the length, angle, contour and other dimensional information of the workpiece. The image measuring instrument can be used to determine whether the machining accuracy of the workpiece meets the industrial design requirements.

[0026] A stage is a component in an image measuring instrument used to support workpieces or other precision devices. In this embodiment, the stage is used to support a standard sample block. Because the stage is movable, the standard sample block located on the stage can be moved to different positions under the action of the stage.

[0027] The movement range of the stage is represented by a coordinate system consisting of the X-axis, Y-axis, and Z-axis. Optionally, the stage may include an X-axis grating, a Y-axis grating, and a Z-axis grating, which are used to determine the position of the stage in the X-axis, Y-axis, and Z-axis directions, respectively, during the stage's movement. Alternatively, the Z-axis grating may be mounted on a camera device, allowing the camera device to move up and down along the column direction to adjust the position in the Z-axis direction.

[0028] Optionally, the image measuring instrument also includes an X-axis drive module, a Y-axis drive module, and a Z-axis drive module, which are respectively connected to the stage. Thus, the X-axis drive module controls the stage to move in the X-axis direction, the Y-axis drive module controls the stage to move in the Y-axis direction, and the Z-axis drive module controls the stage to move in the Z-axis direction.

[0029] A camera device is a component in an image measuring instrument used to photograph an object (exemplarily, the object includes a standard sample, a workpiece, etc.) placed on a platform. Optionally, the camera device may be a camera.

[0030] A laser rangefinder is an optical component in an image measuring instrument used to measure distance. The laser rangefinder is located next to the camera device. The laser rangefinder emits a laser beam and receives the laser beam reflected by the object. It measures the distance between the object surface and the laser rangefinder based on the time of laser beam emission, the time of laser beam reflection, and the speed of light (i.e., time-of-flight ranging) or the intensity of the reflected laser beam (e.g., ranging based on the confocal principle).

[0031] The camera device and the laser rangefinder are respectively set opposite to the platform, meaning that the camera's field of view is aligned with the platform, and the laser rangefinder's range of view is aligned with the platform.

[0032] A standard sample is a reference sample with a known geometry and size, used to help determine the relative position between a camera device and a target laser rangefinder.

[0033] Optionally, the standard sample block has an intersection line formed by the intersection of two faces that is visible to the naked eye; in other words, the intersection line formed by the two faces should be clear enough to ensure that the standard sample block has an intersection line that can be identified by the camera device from the image it acquires. Based on this, the standard sample block has at least two faces. Optionally, the at least two faces of the standard sample block can both be planes, or the at least two faces of the standard sample block can simultaneously have curved surfaces and planes.

[0034] Optionally, the standard sample block may have a missing corner, which is used to locate the orientation of the standard sample block. Thus, even if the angles of each face of the standard sample block are not exactly the same, each different face of the standard sample block can be determined based on the missing corner. That is to say, the missing corner can prevent the different faces of the standard sample block from being confused.

[0035] Optionally, determining that the standard sample is within the ranging range of the target laser rangefinder can be achieved by the user moving the platform on the image measuring instrument to move the standard sample into the ranging range of the target laser rangefinder.

[0036] Optionally, the target laser rangefinder may be the most recently installed laser rangefinder in the image measuring instrument.

[0037] Step 304: During the process of controlling the platform to move along the preset moving path, multiple position points on the standard sample block that are opposite to the target laser rangefinder are measured by the target laser rangefinder.

[0038] The preset movement path refers to the movement path pre-planned for the platform. Optionally, the preset movement path can be pre-entered by the user into the image measuring instrument, so that the platform can move according to the preset movement path when the standard sample is within the ranging range of the target laser rangefinder.

[0039] Measuring multiple points on a standard sample block relative to the target laser rangefinder involves measuring the X-axis, Y-axis, and Z-axis coordinates of each point. The Z-axis coordinate is represented by the vertical distance between the target laser rangefinder and the standard sample block.

[0040] In an exemplary embodiment, the above-described method of measuring multiple position points on a standard sample block relative to the target laser ranging device by means of a target laser ranging device includes: controlling the target laser ranging device to emit a first laser beam; and, when the target laser ranging device receives multiple second laser beams reflected by the standard sample block, determining multiple position points on the standard sample block relative to the target laser ranging device based on the first laser beam and the multiple second laser beams.

[0041] Optionally, multiple points on the standard sample block that are opposite to the target laser rangefinder are not collinear.

[0042] Optionally, multiple location points can be located on at least two faces of the standard sample block, or on all different faces of the standard sample block.

[0043] Optionally, the number of multiple location points can be 3 to 5. Further, the multiple location points can be obtained by measuring 3 to 5 location points on each face of the standard sample block, and the multiple location points measured on each face are not collinear with each other.

[0044] Optionally, the preset movement path can correspond to the geometry of the standard sample block, or in other words, the preset movement path can correspond to the projection shape of the standard sample block on the stage.

[0045] For example, when multiple points are located on different faces of a standard sample, if the projection shape of the standard sample on the stage is triangular, then the preset movement path is also a triangular path. When the preset movement path corresponds to the projection shape of the standard sample on the stage, the graphic depicted by the preset movement path is similar to the projection of the standard sample on the stage.

[0046] For example, three non-collinear positions on a standard sample block opposite to the target laser rangefinder can be measured using a target laser rangefinder.

[0047] In an exemplary embodiment, the above-mentioned measurement of multiple position points on the standard sample block relative to the target laser ranging device by the target laser ranging device includes: determining the X-axis coordinates and Y-axis coordinates of each position point based on the X-axis grating position and Y-axis grating position corresponding to each position point; determining the Z-axis coordinates of each position point based on the measurement results of the laser ranging device; and determining multiple position points on the standard sample block relative to the target laser ranging device based on the X-axis coordinates, Y-axis coordinates, and Z-axis coordinates of each position point.

[0048] Step 306: Determine the first three-dimensional coordinates of the standard sample block based on multiple location points.

[0049] The first three-dimensional coordinates of the standard sample block refer to the three-dimensional coordinates of a certain position point in the standard sample block determined based on multiple position points, consisting of the X-axis coordinates, Y-axis coordinates, and Z-axis coordinates.

[0050] Step 308: Control the stage to move so that the standard sample is within the camera range of the camera device.

[0051] The phrase "the standard sample block is within the camera's field of view" means that the standard sample block is within the camera's field of view, i.e., the camera can acquire complete image data of the standard sample block.

[0052] Step 310: Acquire images including standard sample blocks using a camera device.

[0053] Since the camera device and the stage are positioned opposite each other, the shape of the standard sample in the image corresponds to the shape of the standard sample projected onto the stage.

[0054] Optionally, before acquiring images including standard samples using a camera device, the camera parameters of the camera device can be set so that the camera device can acquire clearer images including standard samples based on pre-set parameters.

[0055] Optionally, such as Figure 2 As shown, the camera device may also include a light source module 26, which emits a light source to enable the camera device to acquire images including the standard sample block with higher clarity. Further optionally, the light source module 26 may include at least one of a ring light module, a coaxial light module, and a bottom light module.

[0056] The ring light module includes multiple light source devices, which are uniformly distributed around the camera device. This allows the ring light module to uniformly illuminate the surface of the standard sample from multiple angles, resulting in higher clarity of the surface features. The coaxial light module's optical axis coincides with the optical axis of the camera device. The coaxial light module can be positioned on the optical axis of the camera device. When used in conjunction with the camera device, the coaxial light module can capture images of the standard sample with enhanced surface details. The bottom light module can be positioned below the stage opposite the camera device to illuminate the standard sample from the bottom upwards, resulting in higher clarity of the bottom features of the standard sample.

[0057] In one exemplary embodiment, the camera device includes a ring light module, and the above-mentioned acquisition of an image including a standard sample block by the camera device includes: determining that the standard sample block is located in the central region of the camera range; and acquiring an image including the standard sample block by the camera device based on the light source signal of the ring light module.

[0058] In this embodiment, when the camera device is equipped with a ring light module, ensuring that the standard sample block is located in the central area of ​​the camera device's imaging range allows the surface of the standard sample block to receive more uniform illumination, thereby obtaining an image with higher display quality and ensuring that the second three-dimensional coordinates of the standard sample block with higher accuracy can be obtained subsequently.

[0059] Step 312: Determine the second three-dimensional coordinates of the standard sample block based on the image.

[0060] The second three-dimensional coordinates of the standard sample block can refer to the three-dimensional coordinates of a point of the standard sample block in the image. For example, it can be the three-dimensional coordinates of the center point of the standard sample block in the image.

[0061] Similarly, the second three-dimensional coordinates of the standard sample are determined by the vertical distance between the X-axis grating, Y-axis grating camera device and the standard sample, as well as the position of the standard sample in the image. The vertical distance between the camera device and the standard sample can refer to the vertical distance between the image sensor in the camera device and the standard sample, the vertical distance between the objective lens and the standard sample, or the vertical distance between the standard sample and a specific height plane (e.g., the surface of stage 12), etc.

[0062] In an exemplary embodiment, the above-mentioned acquisition of an image including a standard sample block by a camera device includes: acquiring an image including a standard sample block by a camera device, and determining the X-axis grating change and Y-axis grating change at the image acquisition position where the stage moves from the target laser rangefinder to the image acquisition position; the above-mentioned determination of the second three-dimensional coordinates of the standard sample block based on the image includes: determining the Z-axis coordinate of the top surface of the standard sample block based on the image and the measurement results of the camera device; determining the position of the first center point of the image based on the X-axis grating position and Y-axis grating position corresponding to the image; selecting multiple boundary lines of the top surface of the standard sample block in the image using a straight line feature extraction tool; determining the position of the second center point of the top surface in the image based on the multiple boundary lines of the top surface; determining the X-axis coordinates and Y-axis coordinates of the standard sample block based on the first center point position, the second center point position, the X-axis grating change, and the Y-axis grating change; and determining the second three-dimensional coordinates of the standard sample block based on the Z-axis coordinates of the top surface, the X-axis coordinates of the standard sample block, and the Y-axis coordinates of the standard sample block.

[0063] The first center point of the image corresponds to the center of the image; the second center point of the top surface corresponds to the position of the center of the top surface of the standard sample block in the image.

[0064] Step 314: Determine the relative position between the camera device and the target laser rangefinder based on the first three-dimensional coordinates and the second three-dimensional coordinates.

[0065] The relative position between the camera device and the target laser rangefinder is determined based on the coordinate difference between the first three-dimensional coordinate and the second three-dimensional coordinate. The coordinate difference between the first three-dimensional coordinate and the second three-dimensional coordinate includes the X-axis coordinate difference, the Y-axis coordinate difference and the Z-axis coordinate difference between the two coordinates.

[0066] Step 316: Determine the position of at least one laser rangefinder in the image measuring instrument based on the relative position between the camera device and the target laser rangefinder.

[0067] The relative position between the camera device and the target laser rangefinder refers to the spatial positional relationship between the camera device and the target laser rangefinder in the coordinate system of the image measuring instrument.

[0068] Since the target laser rangefinder is any one of at least one laser rangefinder, it is easy to understand that the position of at least one laser rangefinder in the image measuring instrument can be determined by determining the relative position between the camera device and the different laser rangefinders.

[0069] Optionally, after determining the position of at least one laser rangefinder within the image measuring instrument, the positions of the camera and the at least one laser rangefinder can be integrated into the same coordinate system of the image measuring instrument. Based on this, the camera and at least one laser rangefinder of the image measuring instrument can work in a coordinated manner, thereby significantly improving the measurement accuracy and reliability of the measurement results.

[0070] Based on the relative positions between the camera device and the target laser rangefinder, their relative positions within the image measuring instrument's coordinate system can be determined. The instrument coordinate system refers to the inherent coordinate system within the image measuring instrument; the definition of its origin and axes depends on the specific design of the image measuring instrument. The instrument coordinate system is used to define the positional relationships and range of motion of the various components of the image measuring instrument.

[0071] In the above measurement method, the standard sample block is determined to be within the ranging range of the target laser ranging device, which is any one of at least one laser ranging device. During the movement of the control platform along a preset path, multiple position points on the standard sample block relative to the target laser ranging device are measured using the target laser ranging device. Based on these multiple position points, the first three-dimensional coordinates of the standard sample block are determined. The control platform is moved to place the standard sample block within the imaging range of the camera device. An image including the standard sample block is acquired using the camera device. Based on the image, the second three-dimensional coordinates of the standard sample block are determined. Based on the first and second three-dimensional coordinates, the relative position between the camera device and the target laser ranging device is determined. Based on the relative position between the camera device and the target laser ranging device, the position of at least one laser ranging device in the image measuring instrument is determined. Using the measurement method provided in this embodiment, the relative position between the camera device and each laser ranging device can be accurately determined with the assistance of the standard sample block, thereby accurately determining the position of at least one laser ranging device in the image measuring instrument.

[0072] In one exemplary embodiment, the measurement method provided in this application can be applied to industrial production. For example, the measurement method provided in this application can be introduced into an assembly line to determine the position of at least one laser rangefinder in an image measuring instrument within the assembly line.

[0073] In one exemplary embodiment, the measurement method provided in this application can also be applied in a laboratory to determine the position of at least one laser rangefinder in an image measuring instrument.

[0074] In one exemplary embodiment, the method further includes:

[0075] Obtain the drawing files of the standard sample block;

[0076] The preset movement path is determined based on the drawing file.

[0077] The drawing file of the standard sample includes the geometry, dimensions, geometric features (for example, geometric features include hole features, groove features, edge features, etc.) of the standard sample, as well as any other geometric measurement information related to the standard sample.

[0078] Alternatively, the drawing file may be in Computer-Aided Design (CAD) format, Drawing Database File (DWG) format, or other industrial file formats.

[0079] In this embodiment, the image measuring instrument can determine the geometric measurement information of the standard sample based on the drawing file of the standard sample. Thus, the image measuring instrument can determine the preset movement path for determining the first three-dimensional coordinates of the standard sample based on the geometric measurement information of the standard sample, which significantly improves the automation level of the determination process of the first three-dimensional coordinates, and consequently significantly improves the measurement efficiency.

[0080] In an exemplary embodiment, the preset movement path includes a first preset movement path and a second preset movement path. The standard sample block includes a top surface, an inclined surface, and a bottom surface, with the area of ​​the top surface being smaller than the area of ​​the bottom surface. During the process of controlling the platform to move along the preset movement path, the measurement of multiple position points on the standard sample block relative to the target laser rangefinder using the target laser rangefinder includes:

[0081] During the process of controlling the platform to move along the first preset moving path, multiple first position points on the inclined surface are measured by the target laser rangefinder.

[0082] During the process of controlling the platform to move along the second preset moving path, multiple second position points on the top surface are measured by the target laser rangefinder;

[0083] Based on multiple location points, the first three-dimensional coordinates of the standard sample block are determined, including:

[0084] The first three-dimensional coordinates of the standard sample block are determined based on multiple first location points and multiple second location points.

[0085] The execution order of the first preset movement path is before the execution order of the second preset movement path.

[0086] The top surface of a standard specimen refers to the surface of the standard specimen furthest from the stage. The bottom surface of a standard specimen refers to the surface of the standard specimen closest to and in close contact with the stage. The inclined surface of a standard specimen refers to the surface used to connect the top and bottom surfaces of the standard specimen. Optionally, the inclined surface may include multiple surfaces, and the number of surfaces included in the inclined surface may be at least three. The top surface, bottom surface, and inclined surface of the standard specimen are all planes.

[0087] It is easy to understand that when the standard sample block includes a top surface, an inclined surface, and a bottom surface, and the area of ​​the top surface is smaller than the area of ​​the bottom surface, the projected shape of the standard sample block on the stage is a polygonal shape. Optionally, the polygonal shape can be a triangular shape, a rectangular shape, a pentagonal shape, or other shapes. Further optionally, the projected shape of the standard sample block on the stage can be a polygonal shape with missing corners.

[0088] The shapes depicted by the first preset movement path and the shapes depicted by the second preset movement path can be similar, meaning they have the same shape but different sizes. Since the area of ​​the top surface is smaller than the area of ​​the bottom surface, the shape depicted by the first preset movement path is larger than the shape depicted by the second preset movement path.

[0089] After the first preset movement path ends, the control platform moves closer to the center area of ​​the standard sample block to control the platform to move according to the second preset movement path.

[0090] Optionally, the multiple first location points can be obtained by measuring 3 to 11 location points on each face of the inclined surface of the standard sample block.

[0091] Optionally, multiple second location points can be obtained by measuring 3 to 11 location points on the top surface of a standard sample block.

[0092] The plurality of first position points on the inclined surface include at least three non-collinear first position points, thereby enabling the equation of the inclined surface to be determined based on the plurality of first position points. Similarly, the plurality of second position points on the top surface include at least three non-collinear second position points, thereby enabling the equation of the top surface to be determined based on the plurality of second position points.

[0093] In an exemplary embodiment, determining the first three-dimensional coordinates of the standard sample block based on a plurality of first location points and a plurality of second location points includes:

[0094] The equation of the inclined surface is determined based on multiple first location points;

[0095] The equation of the top surface is determined based on multiple second location points;

[0096] Based on the equations of the inclined surface and the top surface, determine the equation of the intersection line between the inclined surface and the top surface.

[0097] Based on the equation of the intersection line, the first three-dimensional coordinates of the standard sample block are determined.

[0098] In this way, the equation of the inclined surface can be determined by multiple first position points and a plane fitting algorithm, which is easy to understand based on mathematical theorems. Similarly, the equation of the top surface can be determined by multiple second position points and a plane fitting algorithm.

[0099] In an exemplary embodiment, the above-described method for determining the equation of the intersection line between the inclined surface and the top surface based on the equation of the inclined surface and the equation of the top surface includes: combining the equations of the inclined surface and the top surface to obtain a system of simultaneous equations; and solving the system of simultaneous equations to determine the equation of the intersection line between the inclined surface and the plane.

[0100] Since the inclined surface comprises multiple surfaces, the intersection line between the inclined surface and the top surface comprises multiple lines, and correspondingly, the equation of the intersection line comprises the equations of multiple lines.

[0101] In an exemplary embodiment, the above-mentioned determination of the first three-dimensional coordinates of the standard sample based on the equation of the intersection line includes: determining the coordinates of the intersection points formed by the intersection of pairs of lines among the multiple lines formed by the intersection of the inclined surface and the top surface of the standard sample based on the equation of the intersection line; and determining the first three-dimensional coordinates of the standard sample based on the coordinates of the intersection points formed by the intersection of pairs of lines.

[0102] The coordinates of the intersection points formed by the intersection of any two lines refer to the vertex coordinates of the standard sample block. Based on this, optionally, the first three-dimensional coordinates of the standard sample block can refer to the center coordinates of the top surface of the standard sample block, determined by the target laser rangefinder. For example, if the top surface is a triangle, the coordinates of the three vertices of the triangle can be obtained, and the center coordinates of the triangle can be obtained based on these three vertex coordinates.

[0103] In this embodiment, when the standard sample block includes a top surface, an inclined surface, and a bottom surface, and the area of ​​the top surface is smaller than the area of ​​the bottom surface, multiple first position points on the inclined surface are measured using a target laser rangefinder to determine the equation of the inclined surface, and multiple second position points on the top surface are measured using the same target laser rangefinder to determine the equation of the top surface. Therefore, based on the equations of the inclined surface and the top surface, the equation of the intersection line between the inclined surface and the top surface can be determined. Furthermore, based on the equation of the intersection line, the center coordinates of the top surface of the standard sample block, i.e., the first three-dimensional coordinates, can be determined. Clearly, this embodiment allows for the acquisition of first three-dimensional coordinates with high accuracy and reliability using the target laser rangefinder, which is beneficial for improving the accuracy and reliability of the relative position between the camera device and the target laser rangefinder obtained in subsequent measurements.

[0104] In an exemplary embodiment, the standard sample block includes a top surface, an inclined surface, and a bottom surface, wherein the area of ​​the top surface is smaller than the area of ​​the bottom surface. The above-described determination of the second three-dimensional coordinates of the standard sample block based on the image includes:

[0105] Based on the image, determine the intersection line between the inclined surface and the top surface;

[0106] Based on the intersection line, the second three-dimensional coordinates of the standard sample block are determined.

[0107] One approach is to determine the intersection line between the inclined surface and the top surface based on images and feature recognition algorithms.

[0108] Optionally, the second three-dimensional coordinates of the standard sample block can be determined based on the coordinates of multiple points on the intersection line.

[0109] Optionally, the second three-dimensional coordinates of the standard sample block can refer to the center coordinates of the top surface of the standard sample block determined by the camera device.

[0110] In this embodiment, when the standard sample block includes a top surface, an inclined surface, and a bottom surface, and the area of ​​the top surface is smaller than that of the bottom surface, the intersection line between the inclined surface and the top surface is determined in the image acquired by the camera device and the feature recognition algorithm. Therefore, the center coordinates of the top surface of the standard sample block, i.e., the second three-dimensional coordinates, can be determined based on the intersection line between the inclined surface and the top surface. Clearly, this embodiment can obtain second three-dimensional coordinates with high accuracy and reliability through the camera device, which is beneficial for improving the accuracy and reliability of the relative position between the camera device and the target laser rangefinder obtained in subsequent measurements.

[0111] In an exemplary embodiment, before acquiring images including standard sample blocks using a camera device, the method further includes:

[0112] Determine the distance between the camera device and the standard sample block.

[0113] In an exemplary embodiment, determining the distance between the camera device and the standard sample block includes:

[0114] Determine the distance between the camera device and the standard sample block;

[0115] Determine the camera parameters of the camera device;

[0116] The above-mentioned images of standard sample blocks acquired by the camera device include:

[0117] Images, including standard sample blocks, are acquired using a camera device with a resolution greater than or equal to a first preset resolution.

[0118] The distance between the camera device and the standard sample can be determined by adjusting the height difference between the camera device and the stage. This can be achieved by controlling the camera device to move up and down, or by controlling the camera device to move along the Z-axis. For example, when the camera device is focused on the top surface of the standard sample, the distance between the height of the top surface of the standard sample and a specific height plane (e.g., the surface of stage 12) can be determined based on the Z-axis grating position.

[0119] The first preset resolution is used to enable the image measuring instrument to determine the intersection line between the inclined surface and the top surface based on the image. Therefore, the first preset resolution should meet the condition that the intersection line between the inclined surface and the top surface in the image can be accurately identified.

[0120] Optionally, the first preset sharpness can correspond to the brightness and contrast of the image.

[0121] In this embodiment, before acquiring an image including the standard sample block using the camera device, the distance between the camera device and the standard sample block, as well as the camera parameters of the camera device, are determined. As a result, the camera device can acquire an image including the standard sample block with high clarity. Consequently, the image measuring instrument can accurately determine the intersection line between the inclined surface and the top surface from the image with high clarity, which is beneficial to improving the accuracy and reliability of the relative position between the camera device and the target laser rangefinder obtained in subsequent measurements.

[0122] In an exemplary embodiment, the inclined surface and / or top surface of the standard sample block can also be replaced with a curved surface that can present the intersection line between the two surfaces, thereby enabling the calculation of the center coordinates of the top surface.

[0123] In an exemplary embodiment, the standard sample block includes a recessed opening, a bottom surface, and a curved surface, with the recessed opening positioned opposite to the laser rangefinder and the camera device, respectively.

[0124] The standard sample block, including its concave opening, bottom surface, and curved surface, has a geometric shape resembling a bowl. Correspondingly, the concave opening is positioned opposite the laser rangefinder and the camera, meaning the bowl-shaped standard sample block's concave opening faces both the laser rangefinder and the camera.

[0125] The sharpness of the intersection line between the bottom surface and the curved surface of the standard sample is greater than or equal to the second preset sharpness. The second preset sharpness is used to enable the image measuring instrument to determine the intersection line between the bottom surface and the curved surface based on the image. Therefore, the second preset sharpness should meet the condition that the intersection line between the bottom surface and the curved surface in the image can be accurately identified.

[0126] In an exemplary embodiment, the preset movement path includes a first preset movement path and a second preset movement path. When the standard sample block includes a concave opening, a bottom surface, and a curved surface, the above-mentioned measurement of multiple position points on the standard sample block relative to the target laser rangefinder device via the target laser rangefinder device during the movement of the control platform according to the preset movement path includes:

[0127] During the process of controlling the platform to move along the first preset moving path, multiple third position points on the curved surface are measured by the target laser rangefinder.

[0128] During the process of controlling the platform to move along the second preset moving path, multiple fourth position points on the bottom surface are measured by a laser ranging device.

[0129] In an exemplary embodiment, when the standard sample includes a concave opening, a bottom surface, and a curved surface, the determination of the first three-dimensional coordinates of the standard sample based on multiple third position points and multiple fourth position points includes:

[0130] The equation of the surface is determined based on multiple third location points;

[0131] Determine the equation of the bottom surface based on multiple fourth position points;

[0132] Based on the equations of the surface and the base, determine the equation of the intersection line between the surface and the base;

[0133] Based on the equation of the intersection line, the first three-dimensional coordinates of the standard sample block are determined.

[0134] In this way, the equation of the surface can be determined by multiple third position points and a surface fitting algorithm, which is easy to understand based on mathematical theorems; similarly, the equation of the bottom surface can be determined by multiple fourth position points and a plane fitting algorithm.

[0135] Optionally, in order to reduce the computational cost of determining the equation of the surface, the surface of the bowl-shaped standard sample block in this embodiment is a regular circular surface.

[0136] When the standard sample includes a concave opening, a bottom surface, and a curved surface, the first three-dimensional coordinates of the standard sample can refer to the center coordinates of the bottom surface of the standard sample determined by the target laser rangefinder.

[0137] As is easily understood, since the bottom surface connects to the curved surface, the shape of the bottom surface is a circle, and thus, the intersection line between the curved surface and the bottom surface presents a complete circular curve.

[0138] In an exemplary embodiment, when the standard sample includes a concave opening, a bottom surface, and a curved surface, the above-described determination of the second three-dimensional coordinates of the standard sample based on the image includes:

[0139] Based on the image, determine the image features of the surface;

[0140] Based on the image features of the curved surface, the second three-dimensional coordinates of the standard sample block are determined.

[0141] In cases where the standard sample includes a concave opening, a bottom surface, and a curved surface, the second three-dimensional coordinates of the standard sample can refer to the sphere center coordinates corresponding to the curved surface of the standard sample determined by the camera device.

[0142] Similarly, when the standard sample includes a concave opening, a bottom surface, and a curved surface, the relative position between the camera device and the target laser rangefinder is determined based on the coordinate difference between the first three-dimensional coordinate and the second three-dimensional coordinate.

[0143] In an exemplary embodiment, the flatness tolerance of the top surface, the flatness tolerance of the inclined surface, and the flatness tolerance of the bottom surface are all less than or equal to a first threshold.

[0144] The parallelism between the top and bottom surfaces is less than or equal to the second threshold.

[0145] The flatness tolerances of the top surface, the inclined surface, and the bottom surface respectively characterize the smoothness of the top surface, the inclined surface, and the bottom surface. The smaller the flatness tolerance, the smoother the surface.

[0146] The first threshold can be 0.5. Optionally, the flatness tolerance between the flatness of the top surface, the flatness of the inclined surface, and the flatness of the bottom surface can be 0.5, 0.05, 0.005, or other values.

[0147] The parallelism between the top and bottom surfaces refers to the parallelism error between them. The smaller the parallelism, the closer the top and bottom surfaces are to a parallel state.

[0148] The second threshold can be 0.05. Optionally, the parallelism between the top and bottom surfaces can be 0.05, 0.01, or other values.

[0149] When a standard sample block includes a top surface, an inclined surface, and a bottom surface, and the area of ​​the top surface is smaller than the area of ​​the bottom surface, the flatness of each surface of the standard sample block is relatively high, and the height between the top surface and the bottom surface is close to parallel. Therefore, it is easy to understand that the geometry of the standard sample block in this case presents as a boss.

[0150] In this embodiment, the flatness tolerances of the top surface, the inclined surface, and the bottom surface are all small, resulting in a high degree of flatness for all three surfaces. Simultaneously, the parallelism between the top and bottom surfaces is low, achieving near-ideal parallelism. Using a standard sample block with a specific geometric shape helps improve the accuracy and reliability of the relative position between the camera device and the target laser rangefinder obtained in subsequent measurements.

[0151] The application process of the above measurement method is illustrated below with a detailed embodiment:

[0152] (1) Obtaining the drawing files of standard sample blocks

[0153] Obtain the drawing files of the standard sample block;

[0154] Determine the preset movement path based on the drawing file;

[0155] The preset movement path includes a first preset movement path and a second preset movement path;

[0156] The standard sample block includes a top surface A, inclined surfaces (B1, B2, B3) and a bottom surface. The inclined surfaces consist of three faces. The top surface A has the same shape as the bottom surface, and the area of ​​the top surface A is smaller than the area of ​​the bottom surface. The standard sample block has a missing corner C. Based on this, the top surface A is triangular, and the bottom surface is a triangular shape with a missing corner.

[0157] (2) Determining that the standard sample block is within the ranging range of the target laser ranging device

[0158] The standard sample block is determined to be within the ranging range of the target laser ranging device, which is any one of at least one laser ranging device.

[0159] (3) Determination of multiple first location points and multiple second location points

[0160] During the process of controlling the platform to move along the first preset moving path, multiple first position points on the inclined surface (B1, B2, B3) are measured by the target laser rangefinder;

[0161] During the movement of the control platform along the second preset path, multiple second position points on the top surface A are measured by the target laser rangefinder.

[0162] (4) Determination of the first three-dimensional coordinates of the standard sample block

[0163] Based on multiple first position points, determine the equations of the inclined surfaces (B1, B2, B3); based on multiple second position points, determine the equations of the top surface A.

[0164] Based on the equations of the inclined surfaces (B1, B2, B3) and the equation of the top surface A, determine the equations of the intersection lines (L1, L2, L3) between the inclined surfaces and the top surface. Intersection line L1 is the intersection line between the top surface A and the inclined surface B1, intersection line L2 is the intersection line between the top surface A and the inclined surface B2, and intersection line L3 is the intersection line between the top surface A and the inclined surface B3.

[0165] Based on the equations of the intersection lines (L1, L2, L3), the coordinates of each vertex of the top surface A are determined. Based on the coordinates of each vertex of the top surface A, the coordinates of the midpoint (X1, Y1, Z1) of the standard sample block are determined as the first three-dimensional coordinates.

[0166] (5) Acquisition of images including standard sample blocks

[0167] Control the stage to move so that the standard sample is within the camera's field of view; determine the distance between the camera and the standard sample;

[0168] Determine the camera parameters of the camera device;

[0169] Images, including standard sample blocks, are acquired using a camera device with a resolution greater than or equal to a first preset resolution.

[0170] (6) Determination of the second three-dimensional coordinates of the standard sample block

[0171] Based on the image, determine the intersection line between the inclined surface and the top surface; based on the intersection line, determine the second three-dimensional coordinates (X2, Y2, Z2) of the standard sample block.

[0172] (7) Determining the position of at least one laser rangefinder in the image measuring instrument

[0173] Based on the coordinate differences (X2-X1, Y2-Y1, Z2-Z1) between the first three-dimensional coordinates (X1, Y1, Z1) and the second three-dimensional coordinates (X2, Y2, Z2), the relative position between the camera device and the target laser rangefinder is determined; based on the relative position between the camera device and the target laser rangefinder, the position of at least one laser rangefinder in the image measuring instrument is determined.

[0174] The application process of the above measurement method is illustrated below with another detailed embodiment:

[0175] (1) Obtaining the drawing files of standard sample blocks

[0176] Obtain the drawing files of the standard sample block;

[0177] Determine the preset movement path based on the drawing file;

[0178] The preset movement path includes a first preset movement path and a second preset movement path;

[0179] Figure 4 This is a schematic diagram of the structure of a standard sample block provided in an embodiment of this application, such as... Figure 4 As shown in (a), the standard sample includes a top surface (A, A'), an inclined surface B, and a bottom surface (not shown). The top surface may include top surface A and top surface A'; Figure 4 As shown in (b), the standard sample has a missing corner C. Based on this, the top surface A is a ring with a missing corner, the top surface A' is a circle, and the inclined surface B is a concave conical surface.

[0180] (2) Determining that the standard sample block is within the ranging range of the target laser ranging device

[0181] The standard sample block is determined to be within the ranging range of the target laser ranging device, which is any one of at least one laser ranging device.

[0182] (3) Determination of multiple first location points and multiple second location points

[0183] During the process of controlling the platform to move along the first preset moving path, multiple first position points on the inclined surface B are measured by the target laser rangefinder.

[0184] During the movement of the control platform along the second preset moving path, multiple second position points on the top surface A or top surface A' are measured by the target laser ranging device. For ease of description, the following explanation will take the top surface A as an example.

[0185] (4) Determination of the first three-dimensional coordinates of the standard sample block

[0186] Based on multiple first position points, determine the equation of the inclined surface B; based on multiple second position points, determine the equation of the top surface A or the top surface A'.

[0187] Based on the equations of inclined surface B and top surface A, determine the equation of the intersection line L between the inclined surface and the top surface. The intersection line L is the intersection of top surface A and inclined surface B.

[0188] Based on the equation of the intersection line L, the coordinates (X1, Y1, Z1) of the center of the annulus on the top surface A are determined as the first three-dimensional coordinates.

[0189] (5) Acquisition of images including standard sample blocks

[0190] Control the stage to move so that the standard sample is within the camera's field of view; determine the distance between the camera and the standard sample;

[0191] Determine the camera parameters of the camera device;

[0192] Images, including standard sample blocks, are acquired using a camera device with a resolution greater than or equal to a first preset resolution.

[0193] (6) Determination of the second three-dimensional coordinates of the standard sample block

[0194] Based on the image and feature recognition algorithm, the intersection line L between the inclined surface B and the top surface A is identified; based on the intersection line L, the second three-dimensional coordinates (X2, Y2, Z2) of the standard sample block are determined.

[0195] (7) Determining the position of at least one laser rangefinder in the image measuring instrument

[0196] Based on the coordinate differences (X2-X1, Y2-Y1, Z2-Z1) between the first three-dimensional coordinates (X1, Y1, Z1) and the second three-dimensional coordinates (X2, Y2, Z2), the relative position between the camera device and the target laser rangefinder is determined; based on the relative position between the camera device and the target laser rangefinder, the position of at least one laser rangefinder in the image measuring instrument is determined.

[0197] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0198] In one exemplary embodiment, an image measuring instrument is provided, comprising a movable stage, a camera device, and at least one laser rangefinder device, wherein the camera device and the laser rangefinder device are respectively disposed opposite to the stage, a memory, and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in any of the above-described measurement method embodiments.

[0199] It should be noted that the data involved in this application (including but not limited to data used for analysis, data stored, data displayed, etc.) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0200] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0201] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0202] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A measurement method, characterized in that, An image measuring instrument is applied to a device that includes a movable platform, a camera, and at least one laser rangefinder. The camera and the laser rangefinder are respectively positioned opposite the platform. A standard sample block is placed on the platform. The method includes: The standard sample block is determined to be within the ranging range of the target laser ranging device, wherein the target laser ranging device is any one of the at least one laser ranging devices. During the process of controlling the platform to move along a preset moving path, the target laser rangefinder measures multiple position points on the standard sample block that are opposite to the target laser rangefinder. Based on the multiple location points, determine the first three-dimensional coordinates of the standard sample block; Control the stage to move so that the standard sample is within the imaging range of the camera device; The camera device acquires images including the standard sample block; Based on the image, determine the second three-dimensional coordinates of the standard sample block; Based on the first three-dimensional coordinates and the second three-dimensional coordinates, the relative position between the camera device and the target laser rangefinder is determined. The position of the at least one laser ranging device in the image measuring instrument is determined based on the relative position between the camera device and the target laser ranging device.

2. The method according to claim 1, characterized in that, The method further includes: Obtain the drawing file of the standard sample block; The preset movement path is determined based on the drawing file.

3. The method according to claim 1, characterized in that, The preset movement path includes a first preset movement path and a second preset movement path. The standard sample block includes a top surface, an inclined surface, and a bottom surface. The area of ​​the top surface is smaller than the area of ​​the bottom surface. During the process of controlling the platform to move according to the preset movement path, multiple position points on the standard sample block opposite to the target laser rangefinder are measured by the target laser rangefinder, including: During the process of controlling the platform to move along the first preset moving path, multiple first position points on the inclined surface are measured by the target laser ranging device; During the process of controlling the platform to move along the second preset moving path, multiple second position points on the top surface are measured by the target laser ranging device; Determining the first three-dimensional coordinates of the standard sample block based on multiple location points includes: The first three-dimensional coordinates of the standard sample block are determined based on multiple first location points and multiple second location points.

4. The method according to claim 3, characterized in that, Determining the first three-dimensional coordinates of the standard sample block based on multiple first location points and multiple second location points includes: The equation of the inclined surface is determined based on multiple first location points; The equation of the top surface is determined based on multiple second location points; Based on the equations of the inclined surface and the top surface, determine the equation of the intersection line between the inclined surface and the top surface; Based on the equation of the intersection line, the first three-dimensional coordinates of the standard sample block are determined.

5. The method according to claim 1, characterized in that, The standard sample block includes a top surface, an inclined surface, and a bottom surface, wherein the area of ​​the top surface is smaller than the area of ​​the bottom surface. Determining the second three-dimensional coordinates of the standard sample block based on the image includes: Based on the image, determine the line of intersection between the inclined surface and the top surface; Based on the intersection line, the second three-dimensional coordinates of the standard sample block are determined.

6. The method according to claim 1, characterized in that, Before acquiring the image including the standard sample block through the camera device, the method further includes: Determine the distance between the camera device and the standard sample block.

7. The method according to claim 6, characterized in that, Determining the distance between the camera device and the standard sample block includes: Determine the distance between the camera device and the standard sample block; Determine the camera parameters of the camera device; The acquisition of images including the standard sample block via the camera device includes: The camera device acquires images including the standard sample block with a resolution greater than or equal to a first preset resolution.

8. The method according to claim 1, characterized in that, The standard sample block includes a concave opening, a bottom surface, and a curved surface. The concave opening is respectively positioned opposite to the laser ranging device and the camera device.

9. The method according to claim 3 or 5, characterized in that, The flatness tolerance of the top surface, the flatness tolerance of the inclined surface, and the flatness tolerance of the bottom surface are all less than or equal to the first threshold. The parallelism between the top surface and the bottom surface is less than or equal to the second threshold.

10. An image measuring instrument, comprising a movable platform, a camera device, and at least one laser rangefinder, wherein the camera device and the laser rangefinder are respectively disposed opposite to the platform, a memory, and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 9.

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