Laser scanning system and method for judging size of workpiece in heat treatment furnace

Abstract

The invention discloses a laser scanning system and method for heat treatment furnace workpiece volume judgment, and relates to the technical field of furnace heat treatment, and the method comprises the steps that a first workpiece is obtained, and the first workpiece is put into a preset heat treatment furnace to be scanned; obtaining a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision holders corresponding to the plurality of high-precision laser radars, and scanning a first workpiece through the first laser scanner to obtain a point cloud of the surface of the first workpiece; performing three-dimensional scanning modeling on a preset tray of the heat treatment furnace through a first laser scanner to obtain a 3D imaging model of the heat treatment furnace; and data information related to the volume of the first workpiece is obtained according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and the volume of the first workpiece is calculated through the data information. According to the method, the workpiece volume of the heat treatment furnace can be calculated in a multi-view large view field, so that the use management of the heat treatment furnace is enhanced.

Description

Technical Field

[0001] The present application relates to the field of furnace heat treatment technology, and in particular to a laser scanning system for determining the volume of a workpiece in a heat treatment furnace. Background Art

[0002] Heat treatment furnace refers to an electric furnace or fuel furnace used for heating the charge for heat treatment. Commonly used heat treatment furnaces include box-type resistance furnaces, pit-type resistance furnaces, gas carburizing furnaces and salt bath furnaces. The heat treatment process usually takes about 20 hours. If the workpiece cannot be loaded to the maximum extent allowed by the heat treatment process, it will increase the natural gas consumption and affect the work efficiency.

[0003] In the prior art, the shape and structure of the workpieces processed by the heat treatment furnace are relatively complex. For a long time, the energy consumption assessment method of the heat treatment furnace has only been carried out according to the comparable unit consumption, without considering factors such as the size of the workpiece, which is not conducive to the management and control of the heat treatment furnace, and it is even more impossible to fully utilize the shape characteristics and optimize the heat treatment furnace loading, resulting in low loading. Therefore, how to calculate the volume of the workpiece of the heat treatment furnace under multi-angle and large field of view, avoid scanning blind spots, and thus achieve the purpose of strengthening the use management of the heat treatment furnace and reducing energy consumption is a problem that needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present application is: how to calculate the volume of workpieces in a heat treatment furnace under multi-viewing angles and a large field of view, so as to strengthen the use management of the heat treatment furnace.

[0005] The technical solution adopted by this application to solve its technical problem is:

[0006] In a first aspect, the present application provides a laser scanning system for determining the volume of a workpiece in a heat treatment furnace, the system comprising: a first workpiece module, a point cloud acquisition module, a model building module, and a workpiece volume calculation module, wherein:

[0007] A first workpiece module, used for acquiring a first workpiece and placing the first workpiece into a preset heat treatment furnace for scanning;

[0008] A point cloud acquisition module, used to obtain a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision pan / tilts corresponding to the plurality of high-precision laser radars, and obtain a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner;

[0009] A model building module is used to perform three-dimensional scanning and modeling on a preset tray of a heat treatment furnace by a first laser scanner to obtain a 3D imaging model of the heat treatment furnace;

[0010] The workpiece volume calculation module is used to obtain data information related to the volume of the first workpiece based on the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculate the volume of the first workpiece through the data information.

[0011] Based on the first aspect, further, the above-mentioned multiple high-precision laser radars are two high-precision laser radars installed symmetrically on the left and right of the preset wall.

[0012] Based on the first aspect, further, the point cloud acquisition module is also used to splice point clouds acquired by two high-precision laser radars installed symmetrically on the preset wall to obtain a point cloud of the first workpiece surface.

[0013] Based on the first aspect, further, the workpiece volume calculation module is also used to segment and extract the point cloud of the first workpiece surface by using an axis-aligned bounding box and a directed bounding box to obtain data information related to the first workpiece volume.

[0014] Based on the first aspect, further, the above-mentioned workpiece volume calculation module is also used to project the point cloud in the directed bounding box to the first projection plane based on the first projection plane preset in the directed bounding box, to obtain multiple spatial cylinders, and calculate the total volume of the multiple spatial cylinders as the volume of the first workpiece.

[0015] In a second aspect, the present application provides a laser scanning method for determining the volume of a workpiece in a heat treatment furnace, the method comprising the following steps:

[0016] S1, obtaining a first workpiece, and placing the first workpiece into a preset heat treatment furnace for scanning;

[0017] S2, obtaining a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision pan-tilt platforms corresponding to the plurality of high-precision laser radars, and obtaining a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner;

[0018] S3, performing three-dimensional scanning and modeling of a preset tray of the heat treatment furnace by a first laser scanner to obtain a 3D imaging model of the heat treatment furnace;

[0019] S4, obtaining data information related to the volume of the first workpiece according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculating the volume of the first workpiece through the data information.

[0020] Based on the second aspect, further, the above-mentioned high-precision laser radar adopts a mechanical multi-line laser radar based on the time-of-flight method TOF.

[0021] Based on the second aspect, further, the above-mentioned multiple high-precision laser radars are two high-precision laser radars installed symmetrically on the left and right of the preset wall.

[0022] Based on the second aspect, further, the data information related to the volume of the first workpiece obtained according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace includes:

[0023] The point cloud on the surface of the first workpiece is segmented and extracted using an axis-aligned bounding box and a directed bounding box to obtain data information related to the volume of the first workpiece.

[0024] Based on the second aspect, further, the volume of the first workpiece is obtained by calculating the data information, including:

[0025] Based on a first projection plane preset in the directed bounding box, the point cloud in the directed bounding box is projected onto the first projection plane to obtain a plurality of spatial cylinders, and the total volume of the plurality of spatial cylinders is calculated as the volume of the first workpiece.

[0026] In a third aspect, the present application also provides an electronic device, comprising a memory and a processor; the memory is used to store one or more programs; when one or more programs are executed by the processor, a method as described in any one of the second aspects above is implemented.

[0027] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method according to any one of the above-mentioned second aspects is implemented.

[0028] The beneficial effects of this application are:

[0029] The present application can realize the calculation of the volume of the workpiece of the heat treatment furnace under multi-viewing angle and large field of view, thereby strengthening the use management of the heat treatment furnace, avoiding scanning blind spots, and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A principle block diagram of a laser scanning system for determining the volume of a workpiece in a heat treatment furnace provided in an embodiment of the present application;

[0031] Figure 2 A flow chart of a laser scanning method for determining the volume of a workpiece in a heat treatment furnace provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of high-precision laser radar scanning provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the coordinate relationship between the high-precision laser radar and the high-precision gimbal provided in an embodiment of the present application;

[0034] Figure 5 A schematic diagram of coordinate transformation of point cloud rotation motion provided in an embodiment of the present application;

[0035] Figure 6 An example diagram of the workpiece volume provided for an embodiment of the present application;

[0036] Figure 7 Another example diagram of the workpiece volume provided for an embodiment of the present application;

[0037] Figure 8 Another example diagram of the volume of a workpiece provided in an embodiment of the present application;

[0038] Fig. 9 A structural block diagram of an electronic device provided in an embodiment of the present application.

[0039] The reference numerals are: 100, first workpiece module; 200, point cloud acquisition module; 300, model building module; 400, workpiece volume calculation module; 101, memory; 102, processor; 103, communication interface. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0044] In the description of the embodiments of the present application, "plurality" means at least 2.

[0045] First, as Figure 1 As shown, an embodiment of the present application provides a laser scanning system for determining the volume of a workpiece in a heat treatment furnace, the system comprising: a first workpiece module 100, a point cloud acquisition module 200, a model building module 300 and a workpiece volume calculation module 400, wherein:

[0046] The first workpiece module 100 is used to obtain a first workpiece and place the first workpiece into a preset heat treatment furnace for scanning;

[0047] The point cloud acquisition module 200 is used to obtain a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision pan / tilts corresponding to the plurality of high-precision laser radars, and obtain a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner;

[0048] The model building module 300 is used to enable the first laser scanner to perform three-dimensional scanning and modeling on the preset tray of the heat treatment furnace based on the preset industrial intelligent volume scanning software to obtain a 3D imaging model of the heat treatment furnace;

[0049] The workpiece volume calculation module 400 is used to obtain data information related to the volume of the first workpiece according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculate the volume of the first workpiece through the data information.

[0050] like Figure 3 As shown, in one embodiment of the present application, the above-mentioned multiple high-precision laser radars are two high-precision laser radars installed symmetrically on the left and right of the preset wall.

[0051] In one embodiment of the present application, the high-precision gimbal is composed of a single-axis servo, an angle encoder, precision gears, and a mounting panel.

[0052] In one embodiment of the present application, the workflow of the preset high-precision pan / tilt is as follows:

[0053] Step 1: Function settings (angle | speed | time adjustable)

[0054] The servo is refreshed at a fixed interval, and each time it refreshes one round trip between 0° and 100°; the current maximum resolution is 0.025° per point; set the corresponding scanning field of view angle, step angle and delay time according to the actual scene;

[0055] Step 2: External trigger measurement

[0056] After the high-precision gimbal receives the external trigger signal, the servo starts the continuous motion mode, collects the angle value of the corresponding high-precision laser radar encoder, stores it in the form of data, completes the current scan, and outputs the scan time and point cloud data volume;

[0057] Step 3: Wireless Transmission

[0058] Based on the system's built-in wireless transmission module, the point cloud and high-precision gimbal motion information can be transmitted to the host computer via a wireless bridge, providing raw data for the subsequent volume calculation of the first workpiece.

[0059] like Figure 4 As shown, in one embodiment of the present application, the coordinate relationship between the high-precision laser radar and the high-precision gimbal is:

[0060] Global-XYZ is a global coordinate system, generally designated as a right-hand coordinate system of a fixed scene on site. Base-XYZ is the installation group at the bottom of the gimbal. Base-XYZ and Global-XYZ are fixedly connected. In the case of no global coordinate system in some scenes, Base-XYZ can be replaced by the global coordinate system. Rot-XYZ is the origin coordinate system of the high-precision gimbal, and Lidar-XYZ is the origin coordinate system of the high-precision laser radar. Lidar-XYZ and Rot-XYZ have a spatial geometric relationship of rotation around a fixed axis. This spatial geometric relationship can be used to generate a large field of view point cloud.

[0061] like Figure 5 As shown, in one embodiment of the present application, the specific process of obtaining the point cloud of the first workpiece surface through the coordinate relationship between the high-precision laser radar and the high-precision gimbal is as follows:

[0062] For any point P(p x ,p y ,p z ), find the new point P′(p′) by rotating the angle α around any axis. x ,p′ y ,p′ z), the unit direction vector of the axis is And passes through the point Q(x0,y0,z0);

[0063] Among them, the axis The equation of the straight line in the coordinate system XYZ is:

[0064]

[0065] The plane equation of the preset arc PP' in the coordinate system XYZ is:

[0066] n x (xp x )+n y (yp y )+n z (zp z )=0 (2);

[0067] According to formula (1) and formula (2), and We can obtain:

[0068] t0=n x (p x -x0)+n y (p y -y0)+n z (p z -z0)(3);

[0069] Let the coordinates of the center of arc PP' in coordinate system XYZ be (x c ,y c ,z c ), substitute t0 into equation (1), and the coordinates of the circle center are:

[0070]

[0071] Where, the radius of the circle is r;

[0072]

[0073] Vector OP:

[0074] OP=[p x -x c p y -y c p z -z c ] T / r (6);

[0075] According to the right-hand rule, the coordinate system x'y'z' is established:

[0076] L'=[n x ny n z ] T ×OP (7);

[0077] The rotation transformation matrix between the coordinate system x'y'z' and the coordinate system XYZ is:

[0078]

[0079] The coordinates of point P' in the coordinate system x'y'z' are:

[0080]

[0081] Furthermore, using homogeneous transformation, the coordinates of point P' in the coordinate system x'y'z' are transformed to the coordinates of the coordinate system XYZ:

[0082]

[0083] Simplifying formula (10) yields:

[0084]

[0085] Formula (11) can be expanded and written as:

[0086]

[0087] Among them, in formula (12):

[0088]

[0089] Where K = 1-cos(α), M = n x x0+n y y0+n z z0;

[0090] Based on the above formula, the point cloud of the first workpiece surface is obtained.

[0091] In one embodiment of the present application, the point cloud acquisition module 200 is further used to stitch point clouds acquired by two high-precision laser radars installed symmetrically on the preset wall to obtain a point cloud of the first workpiece surface.

[0092] In one embodiment of the present application, the stitching of point clouds acquired by two high-precision laser radars installed symmetrically on the left and right includes: stitching the point clouds using an iterative nearest point algorithm.

[0093] In one embodiment of the present application, point cloud stitching includes coarse stitching and fine stitching.

[0094] In one embodiment of the present application, the workpiece volume calculation module 400 is also used to segment and extract the point cloud of the first workpiece surface using an axis-aligned bounding box (AABB) and an oriented bounding box (OBB) to obtain data information related to the first workpiece volume.

[0095] In one embodiment of the present application, the data information related to the volume of the first workpiece is the length, width and height of the first workpiece.

[0096] like Figures 6 to 8 As shown, in one embodiment of the present application, the above-mentioned workpiece volume calculation module 400 is also used to project the point cloud in the directed bounding box to the first projection plane based on the first projection plane preset in the directed bounding box, to obtain multiple spatial cylinders, and calculate the total volume of the multiple spatial cylinders as the volume of the first workpiece.

[0097] In one embodiment of the present application, if the volume of the first workpiece is smaller than a preset minimum workpiece volume, an alarm is issued.

[0098] In one embodiment of the present application, if the volume of the first workpiece is not within the effective combustion area of ​​the heat treatment furnace, an alarm is issued.

[0099] In one embodiment of the present application, the maximum length, width and height of the first workpiece are obtained by searching for extreme points of the point cloud that fall into the axis-aligned bounding box and the directed bounding box.

[0100] In one embodiment of the present application, if the value of any one of the maximum length, width, and height of the first workpiece exceeds the effective combustion area of ​​the heat treatment furnace, an alarm is triggered.

[0101] Second, as Figure 2 As shown, an embodiment of the present application provides a laser scanning method for determining the volume of a workpiece in a heat treatment furnace, the method comprising the following steps:

[0102] S1, obtaining a first workpiece, and placing the first workpiece into a preset heat treatment furnace for scanning;

[0103] S2, obtaining a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision pan-tilt platforms corresponding to the plurality of high-precision laser radars, and obtaining a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner;

[0104] S3, performing three-dimensional scanning and modeling of a preset tray of the heat treatment furnace by a first laser scanner to obtain a 3D imaging model of the heat treatment furnace;

[0105] S4, obtaining data information related to the volume of the first workpiece according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculating the volume of the first workpiece through the data information.

[0106] In one embodiment of the present application, the high-precision laser radar adopts a mechanical multi-line laser radar based on the time-of-flight method TOF.

[0107] Thirdly, Fig. 9 As shown, an embodiment of the present application also provides an electronic device, which includes a memory 101 and a processor 102; the memory 101 is used to store one or more programs; when one or more programs are executed by the processor 102, a method as described in any one of the second aspects above is implemented.

[0108] A communication interface 103 may also be included. The memory 101, the processor 102 and the communication interface 103 are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The memory 101 can be used to store software programs and modules, and the processor 102 executes various functional applications and data processing by executing the software programs and modules stored in the memory 101. The communication interface 103 can be used to communicate signaling or data with other node devices.

[0109] Among them, the memory 101 can be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc.

[0110] The processor 102 may be an integrated circuit chip with signal processing capability. The processor 102 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0111] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by the processor 102, a method as in any one of the second aspects described above is implemented. If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk.

[0112] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0113] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A laser scanning system for determining the volume of workpieces in a heat treatment furnace, characterized in that: It includes a first workpiece module, a point cloud acquisition module, a model building module and a workpiece volume calculation module, wherein: A first workpiece module, used for acquiring a first workpiece and placing the first workpiece into a preset heat treatment furnace for scanning; A point cloud acquisition module, used to obtain a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision pan / tilts corresponding to the plurality of high-precision laser radars, and obtain a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner; A model building module is used to perform three-dimensional scanning and modeling on a preset tray of a heat treatment furnace by a first laser scanner to obtain a 3D imaging model of the heat treatment furnace; The workpiece volume calculation module is used to obtain data information related to the volume of the first workpiece according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculate the volume of the first workpiece through the data information.

2. The laser scanning system for determining the volume of workpieces in a heat treatment furnace according to claim 1, characterized in that: The multiple high-precision laser radars are two high-precision laser radars that are symmetrically installed on the preset wall.

3. The laser scanning system for determining the volume of a workpiece in a heat treatment furnace according to claim 2, characterized in that: The point cloud acquisition module is also used to splice the point clouds acquired by two high-precision laser radars installed symmetrically on the preset wall to obtain the point cloud of the first workpiece surface.

4. The laser scanning system for determining the volume of a workpiece in a heat treatment furnace according to claim 1, characterized in that: The workpiece volume calculation module is also used to segment and extract the point cloud of the first workpiece surface using an axis-aligned bounding box and a directed bounding box to obtain data information related to the first workpiece volume.

5. The laser scanning system for determining the volume of a workpiece in a heat treatment furnace according to claim 4, characterized in that: The workpiece volume calculation module is also used to project the point cloud in the directed bounding box onto the first projection plane preset in the directed bounding box to obtain multiple spatial cylinders, and calculate the total volume of the multiple spatial cylinders as the volume of the first workpiece.

6. A laser scanning method for determining the volume of a workpiece in a heat treatment furnace, characterized in that: The following steps are involved: S1, obtaining a first workpiece, and placing the first workpiece into a preset heat treatment furnace for scanning; S2, obtaining a first laser scanner based on a plurality of preset high-precision laser radars and a plurality of high-precision gimbals corresponding to the plurality of high-precision laser radars, and obtaining a point cloud of the surface of the first workpiece after scanning the first workpiece with the first laser scanner; S3, performing three-dimensional scanning and modeling of a preset tray of the heat treatment furnace by a first laser scanner to obtain a 3D imaging model of the heat treatment furnace; S4, obtaining data information related to the volume of the first workpiece according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace, and calculating the volume of the first workpiece through the data information.

7. The laser scanning method for determining the volume of a workpiece in a heat treatment furnace according to claim 6, characterized in that: The high-precision laser radar adopts a mechanical multi-line laser radar based on the time-of-flight method TOF.

8. The laser scanning method for determining the volume of a workpiece in a heat treatment furnace according to claim 6, characterized in that: The multiple high-precision laser radars are two high-precision laser radars that are symmetrically installed on the preset wall.

9. The laser scanning method for determining the volume of a workpiece in a heat treatment furnace according to claim 6, characterized in that: The data information related to the volume of the first workpiece obtained according to the point cloud of the surface of the first workpiece and the 3D imaging model of the heat treatment furnace includes: The point cloud on the surface of the first workpiece is segmented and extracted using an axis-aligned bounding box and a directed bounding box to obtain data information related to the volume of the first workpiece.

10. The laser scanning method for determining the volume of a workpiece in a heat treatment furnace according to claim 6, characterized in that: The step of calculating the volume of the first workpiece through the data information includes: Based on a first projection plane preset in the directed bounding box, the point cloud in the directed bounding box is projected onto the first projection plane to obtain a plurality of spatial cylinders, and the total volume of the plurality of spatial cylinders is calculated as the volume of the first workpiece.

Images