Accurate liquid level measuring device for stirring barrel

Abstract

The invention is suitable for the technical field of material stirring, and provides a stirring barrel liquid level accurate measuring device which comprises a sealing cover located at the top of a stirring barrel body and further comprises a measuring assembly, the measuring assembly is located on the sealing cover and comprises a protective shell fixedly connected to the sealing cover, the protective shell penetrates through the sealing cover in the vertical direction, and the measuring assembly is located on the sealing cover. And a laser radar facing the interior of the stirring barrel body is mounted in the protective shell. The liquid level measuring device has the beneficial effects that the total amount of liquid in the stirring barrel body can be accurately measured and calculated, the position of the liquid level can be calculated even under the condition that the liquid level is unstable, and in conclusion, the liquid level measuring device can accurately measure the liquid level under the condition that the liquid level in the stirring barrel is unstable.

Description

Technical Field

[0001] The invention belongs to the technical field of material mixing, and in particular relates to a device for accurately measuring the liquid level of a mixing barrel. Background Art

[0002] A mixing barrel is a device used to mix materials and is often used in the fields of medicine and chemical industry. For example, in the chemical industry, various raw materials are added to the mixing barrel and mixed into the required liquid.

[0003] The measurement of the liquid level in the mixing tank plays a vital role in industrial production. It is not only related to the safety and efficiency of the process, but also directly affects the quality of the product. Many chemical reactions or mixing processes have strict requirements on the proportion of raw materials. By monitoring the liquid level in real time, it can be ensured that the amount of liquid added is in line with the process formula.

[0004] However, in actual situations, during the rotation of the agitator, the liquid in the mixing barrel will follow its movement, so the liquid surface will produce violent fluctuations or vortices, making it difficult for traditional measurement methods (such as float type and capacitance type) to accurately obtain the true liquid level height, and thus making it impossible to accurately grasp the process. Therefore, a precise measurement device for the liquid level in a mixing barrel is proposed to solve the above problems. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a device for accurately measuring the liquid level in a mixing tank, aiming to solve the problems mentioned in the above background technology.

[0006] The embodiment of the present invention is implemented as follows: a device for accurately measuring the liquid level of a mixing tank includes a cover located on the top of the mixing tank body, and further includes:

[0007] A measuring component, the measuring component is located on the cover, the measuring component includes a protective shell fixedly connected to the cover, the protective shell is arranged to penetrate the cover in a vertical direction, and a laser radar arranged toward the inside of the mixing barrel body is installed in the protective shell;

[0008] When the mixing barrel is stirring, the laser radar scans the inside of the mixing barrel to obtain 3D point cloud data and upload it to the industrial computer. The specific steps include:

[0009] Obtain the overall three-dimensional point cloud data of the interior of the mixing tank generated by the laser radar;

[0010] Separating liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data;

[0011] Generate a three-dimensional model of the liquid surface according to the obtained liquid surface point cloud data;

[0012] The liquid level data of the liquid surface is calculated based on the three-dimensional model of the liquid surface.

[0013] Preferably, a projector is provided on one side of the protective shell on the cover, and the projector is arranged toward the inside of the mixing barrel body, and the projector is used to project a stripe pattern onto the liquid surface in the mixing barrel body.

[0014] Preferably, a rotary drive member is provided at the bottom of the mixing barrel body, and an output end of the rotary drive member is an agitator located inside the mixing barrel body, and the agitator is arranged away from the cover;

[0015] The overall three-dimensional point cloud data includes barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data. The step of separating the liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data specifically includes:

[0016] Use point cloud filtering method to remove noise points in the overall point cloud data;

[0017] The processed overall three-dimensional point cloud data is then downsampled;

[0018] The point cloud segmentation method is used to process the overall three-dimensional point cloud data to obtain barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data.

[0019] Preferably, a foam removal component facing the interior of the mixing barrel body is installed on the cover, and the foam removal component is used to remove foam on the liquid surface.

[0020] Preferably, mounting holes are provided on both sides of the cover, and the foam removal assembly includes a telescopic part fixedly connected in the mounting hole and vertically arranged, and the output ends of the telescopic parts on both sides are fixedly connected with a disk body, and the disk body itself is a mesh structure, and the telescopic part is used to drive the disk body to move in the vertical direction inside the mixing barrel body.

[0021] Preferably, the agitator is a propulsion type structure, and the agitator is used to make the liquid in the mixing barrel body flow along the axial direction.

[0022] Preferably, the protective shell is arranged close to the center of the cover.

[0023] The embodiment of the present invention provides a device for accurately measuring the liquid level in a mixing tank, which has the following beneficial effects:

[0024] The device is located above the stirring barrel body. When measuring the liquid level, the point cloud data of the liquid surface can be scanned by the laser radar, and then a three-dimensional model of the liquid surface can be established using the acquired point cloud data. Even in the case of an unstable liquid surface, the specific distribution of the liquid surface can be accurately known, and the three-dimensional model of the liquid surface can accurately reflect the position of the liquid surface in the current state. The volume of the stirring barrel body is fixed, and the position of the liquid surface relative to the stirring barrel body can be obtained through the overall three-dimensional point cloud data. Therefore, the total amount of liquid in the stirring barrel body can be accurately calculated, and the position of the liquid surface can be calculated even in the case of an unstable liquid surface. In summary, the present invention can perform accurate liquid level measurement for the case of an unstable liquid surface in the stirring barrel, and has a good actual use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A three-dimensional structural diagram of a mixing tank liquid level precision measurement device provided by an embodiment of the present invention;

[0026] Figure 2 A front view of a device for accurately measuring the liquid level in a mixing tank provided by an embodiment of the present invention;

[0027] Figure 3 An internal structural diagram of a mixing barrel body provided in an embodiment of the present invention;

[0028] Figure 4 A three-dimensional structural diagram of a foam removal assembly provided in an embodiment of the present invention;

[0029] Figure 5 A flowchart of scanning the interior of a mixing barrel body by a laser radar to obtain three-dimensional point cloud data and uploading it to an industrial computer provided in an embodiment of the present invention;

[0030] Figure 6 A flow chart of separating liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data provided by an embodiment of the present invention.

[0031] In the attached drawings: 1. mixing barrel body; 2. sealing cover; 3. measuring component; 301. protective shell; 302. laser radar; 4. projector; 5. rotating drive component; 6. agitator; 7. foam removal component; 701. telescopic component; 702. disk body; 8. mounting holes. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0034] like Figure 1 , Figure 2 and Figure 3 As shown, a device for accurately measuring the liquid level in a mixing tank provided by an embodiment of the present invention includes a cover 2 located on the top of a mixing tank body 1, and further includes:

[0035] The measuring component 3 is located on the cover 2. The measuring component 3 includes a protective shell 301 fixedly connected to the cover 2. The protective shell 301 is arranged to penetrate the cover 2 in the vertical direction. A laser radar 302 arranged toward the inside of the mixing barrel body 1 is installed in the protective shell 301. The protective shell 301 is arranged close to the center of the cover 2 to ensure that the laser radar 302 is in the center, so that it can more completely scan the liquid level in the mixing barrel body 1;

[0036] In one embodiment of the present invention, Figure 5 As shown, when the mixing barrel is stirring, the laser radar 302 scans the inside of the mixing barrel body 1 to obtain three-dimensional point cloud data and uploads it to the industrial computer. The specific steps include:

[0037] S100, obtaining the overall three-dimensional point cloud data of the interior of the mixing barrel body 1 generated by the laser radar 302;

[0038] S200, separating liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data;

[0039] S300, generating a three-dimensional model of the liquid surface according to the obtained liquid surface point cloud data;

[0040] S400, obtaining liquid level data of the liquid surface according to the three-dimensional model of the liquid surface.

[0041] In one embodiment of the present invention, the device is located above the stirring barrel body 1. When measuring the liquid level, the point cloud data of the liquid surface can be scanned by the laser radar 302, and then a three-dimensional model of the liquid surface can be established using the acquired point cloud data. Even in the case of an unstable liquid surface, the specific distribution of the liquid surface can be accurately known, and the three-dimensional model of the liquid surface can accurately reflect the position of the liquid surface in the current state, wherein the volume of the stirring barrel body 1 is fixed, and the position of the liquid surface relative to the stirring barrel body 1 can be obtained through the overall three-dimensional point cloud data. Therefore, the total amount of liquid in the stirring barrel body 1 can be accurately calculated, and the position of the liquid surface can be calculated even in the case of an unstable liquid surface. In summary, the present invention can perform accurate liquid level measurement for the unstable liquid surface in the stirring barrel, and has a good actual use effect. It should be noted that the rotating drive member 5 can be in the form of a pneumatic motor, and of course a DC motor can also be used. The output speed of the rotary drive member 5 can be adjusted, so that the stirring efficiency can be adjusted. In addition, when the laser radar 302 is scanned, if the stirring speed in the mixing barrel body 1 is fast, eddies are easily generated on the liquid surface, which makes it very difficult for the laser radar 302 to scan the point cloud. Therefore, when measuring the liquid level, the output speed of the rotary drive member 5 will be reduced. Although it will reduce the stirring rate, it will reduce the fluctuation of the liquid surface, making the scanning of the laser radar 302 easier to achieve. In addition, if the liquid surface fluctuates greatly, the scanned point cloud data may be inaccurate. Therefore, the error can be reduced by taking the average value through multiple scans. Multiple scans mainly increase the scanning frequency of the laser radar 302, record dynamic changes, and calculate the average value. In addition, for the calculation of liquid surface data, because the mixing barrel body 1 is generally a standard cylindrical container, it is known that its bottom is located at z = 0. We can extract the z coordinate values ​​of all points from the three-dimensional model of the liquid surface and calculate its average value as the liquid surface height, for example:

[0042] Extract the z coordinate values ​​of all points from the liquid surface three-dimensional model and record them as {z1,z2,...,z n}.

[0043] Calculate the liquid level:

[0044]

[0045] If more accurate results are required, the influence of liquid level fluctuations can also be considered, and more stable liquid level data can be obtained by performing statistical analysis on the z coordinate values ​​(such as calculating the median or removing extreme values).

[0046] like Figure 3 and Figure 4As shown, as a preferred embodiment of the present invention, a projector 4 is provided on one side of the protective shell 301 on the cover 2, and the projector 4 is arranged toward the inside of the mixing barrel body 1, and the projector 4 is used to project a stripe pattern onto the liquid surface in the mixing barrel body 1.

[0047] In one case of the present embodiment, due to the physical properties of the stirred liquid itself, the liquid surface inside the stirring barrel body 1 may have mirror reflection or diffuse reflection, which makes it impossible for a part of the laser information of the laser radar 302 to be correctly returned during scanning, resulting in incompleteness of the overall three-dimensional point cloud data of the scan. Therefore, artificial texture (i.e., the stripe pattern) can be added to the liquid surface through the projector 4, so as to enhance the reflection characteristics of the liquid surface. Of course, according to the characteristics of the stirred liquid, laser radars 302 of different frequencies or wavelengths can be used to improve the adaptability to the reflection characteristics of different liquids.

[0048] like Figure 3 and Figure 4 As shown, as a preferred embodiment of the present invention, a foam removal component 7 is installed on the cover 2 facing the inside of the mixing barrel body 1, and the foam removal component 7 is used to remove foam on the liquid surface. Mounting holes 8 are opened on both sides of the cover 2. The foam removal component 7 includes a telescopic member 701 fixedly connected in the mounting hole 8 and vertically arranged, and the output ends of the telescopic members 701 on both sides are fixedly connected with a disk body 702, and the disk body 702 itself is a mesh structure. The telescopic member 701 is used to drive the disk body 702 to move in the vertical direction inside the mixing barrel body 1.

[0049] In one case of the present embodiment, when the agitator 6 is stirring the liquid, a large number of bubbles will be generated in the liquid due to the high-speed rotation of the agitator 6, and these bubbles will float to the liquid surface, which will cause a large amount of foam on the liquid surface. Due to the presence of foam, the laser radar 302 cannot scan the point cloud data of the liquid surface. Since the foam itself has a strong reflective property, the above-mentioned structure will be used to remove the foam. When liquid level measurement is required, if there are a large number of bubbles on the liquid surface, the telescopic part 701 will drive the disk 702 to move downward. Since the disk 702 itself is a mesh structure, the disk 702 will move up and down at the position of the liquid surface, thereby breaking the foam on the liquid surface. In addition, the agitator 6 may be in working state at this time, so there will be fluctuations on the liquid surface, but due to the intervention of the disk 702, the original liquid surface can be The motion state is destroyed, and combined with the reduction in the rotation speed of the agitator 6, the liquid surface can be stabilized more quickly, thereby ensuring the accuracy of the measurement. It should be noted that a rotating drive member 5 is provided at the bottom of the mixing barrel body 1, and the output end of the rotating drive member 5 is the agitator 6 located inside the mixing barrel body 1, and the agitator 6 is arranged away from the cover 2. The agitator 6 is a push-type structure, and the agitator 6 is used to make the liquid in the mixing barrel body 1 flow axially. Due to the presence of the laser radar 302, the disk 702 cannot completely cover the liquid surface, so the disk 702 is set to a circular ring shape. When the agitator 6 adopts a push-type structure, the liquid in the mixing barrel body 1 will produce an axial flow in the vertical direction. This liquid flow mode will push the bubbles to move to the edge, which enables the annular disk 702 to play a role in clearing bubbles.

[0050] like Figure 6 As shown, as a preferred embodiment of the present invention, the overall three-dimensional point cloud data includes barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data, and the step of separating the liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data specifically includes:

[0051] S201, using a point cloud filtering method to remove noise points in the overall point cloud data;

[0052] S202, downsampling the processed overall three-dimensional point cloud data;

[0053] S203, using a point cloud segmentation method to process the overall three-dimensional point cloud data to obtain barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data.

[0054] In one case of this embodiment, when actually collecting three-dimensional point cloud data, some abnormal points or noise points may be introduced due to the accuracy limitation of the sensor, environmental interference or target surface characteristics (such as uneven reflectivity). These noise points will interfere with subsequent processing and analysis, so they need to be removed by filtering methods. The filtering method can use statistical filters, conditional filtering or RANSAC filtering. For example, using laser radar 302 to scan a mixing barrel filled with liquid, the collected overall point cloud data contains some isolated points (which may be caused by dust or reflection errors). We can use a statistical filter (SOR) to detect and remove these isolated points. For example, the parameters are set as follows: the neighborhood radius is 0.05 meters, the standard deviation multiple is 2, and all points with an average distance from the surrounding points exceeding twice the standard deviation will be removed. After denoising, the overall three-dimensional point cloud data may still be very dense, which will increase the complexity of subsequent calculations. In order to improve processing efficiency and retain key features at the same time, it is necessary to downsample the point cloud (i.e. reduce the number of points). A voxel grid filter can be used to divide the space into cubes with a side length of 0.01 meters and retain a representative point in each cube. This can significantly reduce the number of points while retaining the overall shape features. After the first two steps, the point cloud data has become clean and sparse. Next, the point cloud needs to be divided into different parts through a segmentation algorithm: barrel wall point cloud, agitator point cloud and liquid surface point cloud. This process usually depends on the geometric characteristics or physical properties of the point cloud. As for the point clouds of the barrel wall and agitator 6, the point clouds formed have very obvious shape characteristics. The height information or geometric shape features are used to distinguish the barrel wall point cloud and the agitator 6 point cloud. For example, the barrel wall point cloud is usually distributed on the outside of the mixing barrel, while the agitator 6 point cloud is located inside the mixing barrel and has a complex shape, so that the required liquid surface point cloud data can be obtained in the overall three-dimensional point cloud data.

[0055] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0057] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A device for accurately measuring the liquid level in a mixing tank, comprising a cover (2) located on the top of a mixing tank body (1), characterized in that: Also includes: a measuring assembly (3), the measuring assembly (3) being located on the sealing cover (2), the measuring assembly (3) comprising a protective shell (301) fixedly connected to the sealing cover (2), the protective shell (301) being arranged to penetrate the sealing cover (2) in a vertical direction, and a laser radar (302) being arranged toward the interior of the mixing barrel body (1) being installed in the protective shell (301); When the mixing barrel is mixing, the laser radar (302) scans the interior of the mixing barrel body (1) to obtain three-dimensional point cloud data and uploads it to the industrial computer. The specific steps include: Acquire the overall three-dimensional point cloud data of the interior of the mixing barrel body generated by the laser radar (302); Separating liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data; Generate a three-dimensional model of the liquid surface according to the obtained liquid surface point cloud data; The liquid level data of the liquid surface is calculated based on the three-dimensional model of the liquid surface.

2. The mixing tank liquid level precision measuring device according to claim 1, characterized in that: A projector (4) is provided on one side of the protective shell (301) on the cover (2), and the projector (4) is arranged toward the inside of the mixing barrel body (1). The projector (4) is used to project a stripe pattern onto the liquid surface in the mixing barrel body (1).

3. The mixing tank liquid level precision measuring device according to claim 1, characterized in that: A rotary drive member (5) is disposed at the bottom of the mixing barrel body (1); an output end of the rotary drive member (5) is an agitator (6) located inside the mixing barrel body (1), and the agitator (6) is disposed away from the cover (2); The overall three-dimensional point cloud data includes barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data. The step of separating the liquid surface point cloud data belonging to the liquid surface from the overall three-dimensional point cloud data specifically includes: Use point cloud filtering method to remove noise points in the overall point cloud data; The processed overall three-dimensional point cloud data is then downsampled; The point cloud segmentation method is used to process the overall three-dimensional point cloud data to obtain barrel wall point cloud data, agitator point cloud data and liquid surface point cloud data.

4. The device for accurately measuring the liquid level in a mixing tank according to claim 3, characterized in that: The sealing cover (2) is provided with a foam removal component (7) facing the interior of the stirring barrel body (1), and the foam removal component (7) is used to remove foam on the liquid surface.

5. The device for accurately measuring the liquid level in a mixing tank according to claim 4, characterized in that: The cover (2) is provided with mounting holes (8) on both sides. The foam removal component (7) comprises a telescopic member (701) fixedly connected in the mounting holes (8) and arranged vertically. The output ends of the telescopic members (701) on both sides are fixedly connected with a disk body (702). The disk body (702) itself is a mesh structure. The telescopic member (701) is used to drive the disk body (702) to move in the vertical direction inside the mixing barrel body (1).

6. The device for accurately measuring the liquid level in a mixing tank according to claim 3, characterized in that: The stirrer (6) is a propulsion type structure and is used to make the liquid in the stirring barrel body (1) flow along the axial direction.

7. The device for accurately measuring the liquid level in a mixing tank according to claim 1, characterized in that: The protective shell (301) is arranged close to the center of the sealing cover (2).

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