Method and system for automatically adding covering agent to crown block in electrolytic aluminum workshop

Abstract

The invention particularly relates to an automatic covering agent adding method and system for an electrolytic aluminum workshop crown block. The automatic covering agent adding method comprises the steps that an electrolytic aluminum tank is scanned, segmentation is conducted through a plane segmentation model, so that the surface of electrolytic aluminum liquid and the surface of a first covering agent are obtained, and the surface height of the surface of the electrolytic aluminum liquid is calculated; dividing the whole electrolytic aluminum tank into a plurality of covering areas based on the electrolytic aluminum liquid surface and the first covering agent surface, and obtaining the covering agent demand quantity of each covering area according to the received covering agent thickness threshold value, the surface height and the first covering agent surface; generating a feeding path in the coverage area, and controlling a crown block to drive a rigid material distribution pipe to automatically add a covering agent according to the feeding path and the covering agent demand quantity; and after the covering agent adding procedure in the feeding path is completed, the electrolytic aluminum tank is scanned again to obtain a second covering agent surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic electrolytic aluminum factory without manual work, and particularly relates to a method and system for automatically adding covering agent to a crane in an electrolytic aluminum workshop. BACKGROUND

[0002] In the process of electrolytic aluminum production, a layer of covering agent needs to be covered on the surface of the electrolytic aluminum liquid in the electrolytic cell to ensure stable production and good production indicators. The covering agent should uniformly and stably cover the electrolytic cell liquid surface, and the thickness is generally controlled between 10 to 50 millimeters. The specific thickness will be adjusted according to the type of covering agent, cell type and process conditions. The covering agent plays a crucial role in preventing the direct exposure of the electrolytic aluminum liquid surface to the air, reducing the contact between the electrolytic aluminum liquid and the moisture and carbon dioxide in the air, and thus reducing carbon consumption and side reactions. If the covering layer is too thin, the protection effect is not good, and it cannot effectively block the contact between air and electrolytic aluminum liquid, which will lead to increased carbon consumption, intensified side reactions, and affect the quality and production efficiency of electrolytic aluminum; and if the covering layer is too thick, it will increase the production cost, and may also affect the electrolysis efficiency, such as hindering the discharge of gas in the electrolysis process.

[0003] At present, in most electrolytic aluminum production enterprises, manual addition of covering agent is still commonly used. However, this traditional manual addition method has many obvious disadvantages, which seriously restricts the further development of electrolytic aluminum production.

[0004] Some existing technologies use automatic feeding or replenishing methods, among which the most common one is to use a fixed Z-shaped moving track for balanced addition. However, this fixed program addition method has obvious defects in actual application. Due to the fluid characteristics, part of the original covering agent on the surface of the electrolytic aluminum liquid will sink into the liquid surface, resulting in uneven surface of the covering agent, and some areas are completely exposed to the surface of the electrolytic aluminum liquid. The automatic addition method with fixed Z-shaped movement cannot dynamically adjust according to the actual unevenness of the surface of the electrolytic aluminum liquid and the distribution of the covering agent, it only operates according to the preset fixed path and addition amount, and finally still leads to uneven distribution of the covering agent, some areas have too thick covering agent, and some areas have too thin covering agent or even expose the surface of the electrolytic aluminum liquid (as shown in Figure 1 ).

[0005] Therefore, the present application is proposed. SUMMARY

[0006] To solve the problem that the existing electrolytic aluminum covering agent adding mode (manual or fixed Z-shaped automatic adding) cannot dynamically adapt to the uneven surface of the electrolytic aluminum liquid, resulting in uneven distribution of the covering agent (local over-thickness / over-thinness or even exposure of the liquid surface), manual secondary intervention is required, which affects the production efficiency and quality, the application provides an electrolytic aluminum workshop overhead crane automatic covering agent adding method and system based on real-time surface detection and dynamic path planning.

[0007] To solve the above technical problems, the application provides an electrolytic aluminum workshop overhead crane automatic covering agent adding method, which comprises the following steps: scanning an electrolytic aluminum tank and dividing it by a plane segmentation model to obtain an electrolytic aluminum liquid surface and a first covering agent surface, and calculating the surface height of the electrolytic aluminum liquid surface; dividing the entire electrolytic aluminum tank into a plurality of covering areas based on the electrolytic aluminum liquid surface and the first covering agent surface, and obtaining the covering agent demand of each covering area according to the received covering agent thickness threshold, the surface height and the first covering agent surface; generating a feeding path in the covering area, and controlling the overhead crane to drive a rigid cloth pipe to automatically add covering agent according to the feeding path and the covering agent demand; after completing the covering agent adding process under the feeding path, scanning the electrolytic aluminum tank again to obtain a second covering agent surface; fitting the planeness of the second covering agent surface and obtaining a supplementary area, and again controlling the overhead crane to drive the rigid cloth pipe to sequentially supplement the supplementary area until the planeness meets a preset planeness threshold.

[0008] In a further aspect of the application, the scanning of the electrolytic aluminum tank and the division by the plane segmentation model to obtain the electrolytic aluminum liquid surface and the first covering agent surface, and the calculation of the surface height of the electrolytic aluminum liquid surface, comprises: coarsely dividing target point clouds in the scanned electrolytic aluminum tank three-dimensional data within a preset height range; selecting a reference point in the target point cloud, and constructing a first vector and a second vector from two points in the neighborhood of the reference point; obtaining a normalized plane normal vector through the cross product calculation of the first vector and the second vector; fitting an initial plane model based on the initially calculated plane normal vector and the calculated distance parameter; calculating the point cloud distance of the point cloud in the target point cloud to the initial plane, and selecting points with a point cloud distance less than a preset distance threshold as inliers; based on the inlier set, recalculating the vector and the normal vector to fit a new plane model, and repeatedly selecting the reference point for a preset number of times threshold, retaining the plane model with the largest number of inliers as the optimal solution of the electrolytic aluminum liquid surface; calculating the average height of the inlier set in the electrolytic aluminum liquid surface as the surface height of the electrolytic aluminum liquid; and performing point cloud segmentation through the electrolytic aluminum liquid surface to obtain the first covering agent surface.

[0009] In a further solution of the present application, the entire electrolytic aluminum tank is divided into several covering areas based on the surface of the electrolytic aluminum liquid and the covering agent surface, and the covering agent requirement of each covering area is obtained according to the received covering agent thickness threshold, the surface height and the first covering agent surface, including: marking the surface of the electrolytic aluminum liquid as the first area, and marking the first covering agent surface as the second area; in the first area, calculating the covering agent requirement based on the height difference between the surface height and the covering agent thickness threshold; in the second area, judging whether the second area is a flat surface; if the second area is a flat surface, calculating the covering agent requirement according to the average height of the second area and the height difference between the covering agent thickness threshold; if the second area is a non-flat surface, calculating the covering agent requirement according to the low point of the second area, the low point and the covering agent thickness threshold.

[0010] In a further solution of the present application, the determination of whether the second area is a flat surface includes: for each point cloud in the second area, querying its neighborhood within a preset constraint radius; calculating the height standard deviation within the neighborhood, and if the height standard deviation is less than a preset standard deviation threshold, determining it to be a flat surface; if the height difference is greater than the preset standard deviation threshold, determining it to be a non-flat surface.

[0011] In a further scheme of the present application, the covering agent requirement is calculated based on the low point of the second area using the low point and the covering agent thickness threshold, including: traversing all point cloud data in the second area to obtain the minimum height and the maximum height; performing point cloud volume calculation in the bounding box from the minimum height to the maximum height in the second area to obtain the point cloud volume of the second area, and subtracting the point cloud volume of the second area from the bounding box volume to calculate the first requirement; calculating the second requirement based on the second difference between the maximum height and the covering agent thickness threshold; and accumulating the first requirement and the second requirement to obtain the covering agent requirement.

[0012] In a further solution of the present application, a feeding path is generated in the covering area, and the overhead crane is controlled to drive the rigid distribution pipe to automatically add covering agent according to the feeding path and the covering agent demand, including: in the first area or the second area with a flat surface, a Z-shaped route is used to add covering agent; in the second area with a non-flat surface, fixed-point feeding is first performed at the low point and then covering agent is added using a Z-shaped route.

[0013] In a further aspect of the present application, the planeness of the second covering agent surface is fitted and an additional area is obtained, and the crown is controlled to drive the rigid cloth pipe to sequentially add covering agent to the additional area until the planeness meets a preset planeness threshold, comprising: obtaining a least square fitting plane on the second covering agent surface; calculating the maximum distance and minimum distance of the points on the second covering agent surface to the least square fitting plane, and taking the difference between the maximum distance and the minimum distance as the planeness; taking the area below the height of the least square fitting plane in the second covering agent surface as the additional area; when the planeness is greater than the preset planeness threshold, controlling the crown to drive the rigid cloth pipe to quantitatively add covering agent to the additional area sequentially; after each round of addition is completed, the planeness is calculated again, and if the planeness is still greater than the planeness threshold, the crown is controlled to drive the rigid cloth pipe to quantitatively add covering agent to the additional area sequentially until the planeness is less than the planeness threshold.

[0014] The second aspect of the present application also provides an automatic covering agent adding system for a crown of an aluminum electrolysis workshop, comprising: a crown; a laser radar scanner connected to the crown and used for scanning an aluminum electrolysis tank; a rigid cloth pipe connected to the crown and used for releasing covering agent; and a controller electrically controlling the crown, the laser radar scanner and the rigid cloth pipe, and configured to execute the automatic covering agent adding method for the crown of the aluminum electrolysis workshop.

[0015] Further, the rigid cloth pipe comprises a control valve used for controlling the opening or closing of the release of the covering agent; and the controller is further configured to: when controlling the crown to drive the rigid cloth pipe to automatically add covering agent according to the adding path and the covering agent demand, the flow rate of the rigid cloth pipe per unit time is constant, and the running speed and / or the residence time of the crown are calculated according to the covering agent demand to control the covering agent demand.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The automatic covering agent adding method for the crown of the aluminum electrolysis workshop provided by the present application can accurately obtain the information of the surface of the aluminum electrolyte and the first covering agent surface through scanning and planar segmentation model, and calculate the covering agent demand of each covering area, so as to accurately control the adding amount of the covering agent according to the actual situation, generate a reasonable adding path and control the crown to add covering agent according to the path, and simultaneously perform scanning and addition operation on the added covering agent surface, so as to ensure that the covering agent is uniformly distributed in the entire aluminum electrolysis tank and avoid the occurrence of areas with too thick or too thin covering agent. The entire process is automatically completed by the crown and the rigid cloth pipe, reduces manual intervention, reduces labor intensity, and improves production efficiency.

[0018] Other features and advantages of the embodiments of the present application will be described in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of a covering agent for electrolytic aluminum liquid in an electrolytic cell provided in an embodiment of the present application;

[0021] Figure 2 This is a flow chart of a method for automatically adding a covering agent to an overhead crane in an electrolytic aluminum workshop provided in an embodiment of the present application;

[0022] Figure 3 This is a schematic diagram of the volume of the covering agent required for the first area and the second area in step S20 demonstrated in an embodiment of the present application;

[0023] Figure 4 This is a module schematic diagram of the automatic covering agent adding system for the overhead crane in the electrolytic aluminum workshop provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The terms "second direction", "first direction", "third direction", "inside", "outside" and the like that appear below to indicate directions or positional relationships, unless otherwise specified, are to be understood as being based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting this application.

[0025] Furthermore, the use of "first" or "second" in describing features is for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features identified. Features identified as "first" or "second" may explicitly or implicitly include at least one of the identified features. The use of the word "plurality" generally implies at least two, such as two or three, unless otherwise specifically defined.

[0026] In the present application, unless specifically defined and limited otherwise, the terms "mount", "connect", "connect", "fix", and the like should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the description of the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0028] In the actual production process of electrolytic aluminum, the electrolytic aluminum liquid in the electrolytic cell is not static, and due to the structural characteristics of the electrolytic cell, such as the arrangement of the anode and the cathode, the shape of the electrolytic cell, etc., the electrolytic aluminum liquid will form a specific flow pattern in the cell. Generally, the flow of electrolytic aluminum liquid near the cell wall is relatively slow, at the same time, a large amount of gas will be generated during the electrolytic aluminum reaction, which will produce an upward impact force on the covering agent, causing the covering agent to spread around, and as the gas continues to escape, the covering agent in some areas will gradually decrease, causing the covering agent in some areas to gradually decrease, resulting in unevenness, which can form two situations, one is that some areas are exposed to the surface of the electrolytic aluminum liquid, and the other is that the covering agent is formed along the middle depression.

[0029] As Figure 2 Therefore, one general concept of the present application provides an automatic covering agent adding method for electrolytic aluminum workshop crown block, the automatic covering agent adding method comprises:

[0030] Step S10, scanning the electrolytic aluminum cell and dividing by the plane segmentation model to obtain the electrolytic aluminum liquid surface and the first covering agent surface, and calculating the surface height of the electrolytic aluminum liquid surface;

[0031] Step S20, dividing the entire electrolytic aluminum cell into a plurality of covering areas based on the electrolytic aluminum liquid surface and the first covering agent surface, and obtaining the covering agent demand of each covering area according to the received covering agent thickness threshold, the surface height and the first covering agent surface;

[0032] Step S30, generating a feeding path in the coverage area and controlling the crown to drive the rigid material pipe to automatically add the covering agent according to the feeding path and the covering agent demand;

[0033] Step S40, after completing the covering agent adding process under the feeding path, scanning the electrolytic aluminum tank again to obtain a second covering agent surface;

[0034] Step S50, fitting the planeness of the second covering agent surface and obtaining a supplement area, and again controlling the crown to drive the rigid material pipe to supplement the supplement area in turn until the planeness meets the preset planeness threshold.

[0035] It can be understood that the electrolytic aluminum tank is a device in the electrolytic aluminum production process, which is used to hold electrolytic aluminum liquid and convert raw materials such as alumina into aluminum metal through electrolysis reaction; the electrolytic aluminum liquid surface is the top surface of the electrolytic aluminum liquid, and the first covering agent surface is the covering agent on the current electrolytic aluminum liquid surface. Generally speaking, the electrolytic aluminum liquid surface is a plane, and the first covering agent surface is a concave-convex surface; and the surface height refers to the vertical distance of the electrolytic aluminum liquid surface relative to a certain reference plane (such as the ground).

[0036] The covering agent thickness threshold is a preset thickness value of the covering agent on the electrolytic aluminum liquid surface, the feeding path refers to the trajectory of the crown driving the rigid material pipe to move above the electrolytic aluminum tank, and the adding operation of the covering agent is performed according to the path; the rigid material pipe is a pipeline for conveying and spreading the covering agent, which has the characteristics of rigidity, can ensure the stability of the shape of the material pipe during the adding process, and thus realize more accurate spreading of the covering agent; the planeness threshold is a preset qualified standard of the flatness of the covering agent surface, when the planeness of the covering agent surface reaches the threshold, it is considered that the adding of the covering agent meets the requirements.

[0037] Based on the above one general inventive concept, first, a scanning device (such as a laser scanner) is used to comprehensively scan the electrolytic aluminum tank to obtain three-dimensional data or image information; a plane segmentation model is used to process the scanning data to accurately distinguish the electrolytic aluminum liquid surface and the first covering agent surface, and calculate the height of the electrolytic aluminum liquid surface relative to the reference plane, to provide basic data for subsequent calculation of the covering agent demand.

[0038] It can be understood that since the first covering agent surface has different thicknesses above the electrolytic aluminum liquid surface, or some areas are not covered by the covering agent. According to the distribution of the electrolytic aluminum liquid surface and the first covering agent surface, the electrolytic aluminum tank can be reasonably marked and divided into multiple coverage areas, and the covering agent adding amount required by each coverage area can be calculated in combination with the preset covering agent thickness threshold, the height of the electrolytic aluminum liquid surface, and the state of the current covering agent surface.

[0039] According to the divided coverage area and the coverage agent demand of each area, the feeding path of the overhead traveling crane driving the rigid material pipe is planned to ensure that the coverage agent can be uniformly and accurately added to each area; the overhead traveling crane is controlled to move according to the generated feeding path, and at the same time, the rigid material pipe spreads the coverage agent into the aluminum electrolysis cell according to the calculated demand.

[0040] When a complete coverage agent adding process is completed, the scanning device is used again to scan the aluminum electrolysis cell to obtain the coverage agent surface state after the coverage agent is added, that is, the second coverage agent surface; the second coverage agent surface is fitted for flatness to analyze the flatness of the coverage agent surface and find out the uneven area, that is, the supplementary area.

[0041] The overhead traveling crane drives the rigid material pipe to perform the supplementary operation of the coverage agent on the supplementary area in turn, and the scanning and supplementary processes are repeated until the flatness of the coverage agent surface reaches the preset flatness threshold, so as to ensure that the coverage agent is uniformly distributed on the surface of the aluminum electrolysis liquid.

[0042] For differentiation, the first coverage agent surface is referred to as the initial coverage agent surface, and the second coverage agent surface is referred to as the surface after the coverage agent is added on the first coverage agent surface.

[0043] Through the above, the scanning and the plane segmentation model accurately obtain the information of the surface of the aluminum electrolysis liquid and the first coverage agent surface, and calculate the coverage agent demand of each coverage area, so as to accurately control the adding amount of the coverage agent according to the actual situation, generate a reasonable feeding path, control the overhead traveling crane to add the coverage agent according to the path, and scan and supplement the second coverage agent surface after the addition, so as to ensure that the overall coverage agent is uniformly distributed in the entire aluminum electrolysis cell, avoid the occurrence of areas with too thick or too thin coverage agent, and automatically complete the entire process by the overhead traveling crane and the rigid material pipe, thereby reducing manual intervention, reducing labor intensity, and improving production efficiency.

[0044] In step S10, the aluminum electrolysis cell is scanned and segmented by a plane segmentation model to obtain the surface of the aluminum electrolysis liquid and the coverage agent surface, and the surface height of the aluminum electrolysis liquid is calculated, including:

[0045] In step S11, the target point cloud is coarsely segmented in the scanned three-dimensional data of the aluminum electrolysis cell within a preset height range;

[0046] In step S12, a reference point and two points in the neighborhood of the reference point are selected in the target point cloud to construct a first vector and a second vector, respectively;

[0047] In step S13, a normalized plane normal vector is obtained by calculating the cross product of the first vector and the second vector;

[0048] In step S14, an initial plane model is fitted based on the initially calculated plane normal vector and the calculated distance parameter.

[0049] Step S15, calculate the point cloud distance of the point cloud in the target point cloud to the initial plane, and screen out the points with a point cloud distance less than a preset distance threshold as inner points;

[0050] Step S16, based on the inner point set, re-calculate the vector and normal vector to fit a new plane model, and repeat the selection of the reference point for a preset number of times threshold, and retain the plane model with the largest number of inner points as the optimal solution of the surface of the molten aluminum electrolyte;

[0051] Step S17, calculate the average height of the inner point set in the surface of the molten aluminum electrolyte as the surface height of the molten aluminum electrolyte.

[0052] It can be understood that assuming that the three-dimensional data of the electrolytic aluminum tank obtained by scanning is a point cloud set P = {p1, p2, …, pn}, wherein each point pi = (xi, yi, zi), i = 1, 2, …, n, n is the total number of point clouds, the point cloud set Z ∈ [h-0.3m, h+0.3m] can be retained according to prior knowledge, i.e. the target point cloud, the purpose of which is to reduce the data amount of subsequent calculation and improve processing efficiency.

[0053] A point p base =(x base ,y base ,z base ) is randomly selected from the target point cloud set as a reference point; after determining the neighborhood range of the reference point, two different points in the neighborhood of the reference point are selected, such as p1 = (x1, y1, z1) and p2 = (x2, y2, z2); two vectors are constructed through the three points extracted together, then the first vector and the second vector can be respectively: v1 = (x1-x base ,y1-y base ,z1-z base ) and the second vector v2 = (x2-x base ,y2-y base ,z2-z base ).

[0054] After calculating the cross product of the first vector and the second vector, the normal vector is obtained after normalization processing; the vector obtained by cross product calculation is perpendicular to the plane where v1 and v2 are located, and the vector is the normal vector of the plane. The normalization processing is to eliminate the influence of the length of the normal vector on the subsequent plane equation calculation, so that the normal vector only represents the direction information of the plane.

[0055] Let the initial plane normal vector be n norm =(A,B,C), the reference point p base =(x base ,y base ,z base). According to the general formula of the plane equation Ax + By + Cz + d = 0, the reference point is substituted into the equation, and D = -(Ax + By + Cz + d) is obtained. base +By base +Cz base ).

[0056] A distance parameter d is set, which can be set according to the possible error range of the surface of the electrolytic aluminum liquid. When fitting the plane, it can be assumed that the distance from the points on the plane to the reference point does not exceed d. By adjusting the parameters of the plane equation, as many points as possible that satisfy this condition are obtained, thereby obtaining an initial plane model.

[0057] For any point in the set of target point clouds except the reference point, the distance from the point to the initial plane model is calculated. A distance threshold is preset. If the distance from the point to the initial plane is less than the distance threshold, the point is marked as an inner point and added to the inner point set. A point is randomly selected from the inner point set as a new reference point. Then, the vector and normal vector are recalculated according to the method of steps S12-S15, a new plane model is fitted, and a new inner point set is selected.

[0058] The above process is repeated for a preset number threshold N times. After each iteration, the size of the current inner point set is recorded. After all N iterations are completed, the plane model with the most inner points is selected as the surface of the electrolytic aluminum liquid. The process of repeatedly selecting the reference point and iteratively fitting the plane model is to fully consider the randomness and noise in the point cloud data, and to find the plane model that best fits the surface of the electrolytic aluminum liquid through multiple attempts. The plane model with the most inner points is retained because the more inner points there are, the higher the degree of fit between the plane model and the surface of the electrolytic aluminum liquid. Then, the average height of the inner point set formed by all the inner points, i.e. the surface height, is calculated.

[0059] Further, in step S10, the electrolytic aluminum tank is scanned and segmented by the plane segmentation model to calculate the surface height of the electrolytic aluminum liquid and the first covering agent surface, further comprising:

[0060] Segmenting the point cloud on the surface of the electrolytic aluminum liquid to obtain the first covering agent surface.

[0061] First, the segmentation boundary condition is determined, i.e. the surface height of the electrolytic aluminum liquid has been calculated in step S16. Based on this height, a height threshold range is set, and the scanned three-dimensional point cloud data of the electrolytic aluminum tank is traversed. For each point, it is determined whether the z coordinate satisfies the height threshold range. If it satisfies, the point is marked as a point that may belong to the first covering agent surface and added to the candidate point set, thereby achieving segmentation to obtain the first covering agent surface.

[0062] Further based on the general concept of the present application, in step S20 of the embodiment of the present application, the entire electrolytic aluminum tank is divided into several coverage areas based on the electrolytic aluminum liquid surface and the covering agent surface, and the covering agent demand of each coverage area is obtained according to the received covering agent thickness threshold, surface height and first covering agent surface, including:

[0063] Step S21, marking the electrolytic aluminum liquid surface as a first area and the first covering agent surface as a second area;

[0064] Step S22, under the first area, calculating the covering agent demand based on the height difference between the surface height and the covering agent thickness threshold;

[0065] Step S23, under the second area, judging whether the second area is a flat surface;

[0066] Step S24, if the second area is a flat surface, calculating the covering agent demand according to the height difference between the average height of the second area and the covering agent thickness threshold;

[0067] Step S25, if the second area is not a flat surface, calculating the covering agent demand according to the low point of the second area and the height difference between the low point and the covering agent thickness threshold.

[0068] The first area can be simply understood as an area that is not directly exposed to the electrolytic aluminum liquid surface by the covering agent itself, and the second area is an area with the first covering agent surface, that is, the first area is a plane and the second area is a concave-convex surface with different heights.

[0069] The purpose of marking is to classify and distinguish different surfaces in the electrolytic aluminum tank for easy identification, and to prepare for subsequent calculation of covering agent demand for different areas. Assuming that the area of the first area scanned is S1, the area of the electrolytic aluminum liquid surface point cloud can be estimated, and the calculation formula of the covering agent demand V1 is V1=S1×(covering agent thickness threshold-surface height). If the mass m1 of the covering agent needs to be calculated, the density p of the covering agent is known, then m1=V1×p=S1×(covering agent thickness threshold-surface height)×p. This step is an estimation based on an ideal situation, that is, it is assumed that a layer of covering agent with a thickness reaching the covering agent thickness threshold needs to be uniformly covered on the electrolytic aluminum liquid surface. By calculating the height difference between the covering agent thickness threshold and the surface height, and by multiplying the height difference by the area S1, the required covering agent volume is obtained, and the mass can be calculated, providing a quantity reference for actual addition of covering agent.

[0070] Of course, those skilled in the art can also directly measure the covering agent demand by volume, and such improvement still falls within the protection scope covered by the present application.

[0071] In one feasible method of step S23, for the point cloud data of the second region (the surface of the first covering agent), the neighborhood normal vector of each point in the second region is calculated, and then the directional difference of these normal vectors is counted. If the directional difference of most normal vectors is within a small range, it is considered that the region is a flat surface. For example, by calculating the included angle between the normal vectors, a threshold angle is set, and when the proportion of points with an included angle less than the threshold angle exceeds a preset proportion, it is considered that the region is a flat surface.

[0072] In the preferred scheme of the present application, the step S23 of judging whether the second region is a flat surface comprises:

[0073] Step S231, for each point cloud of the second region, query the neighborhood within the preset constraint radius thereof;

[0074] Step S232, calculate the height standard deviation in the neighborhood, if the height standard deviation is less than a preset standard deviation threshold, it is determined as a flat surface; if the height difference is greater than the preset standard deviation threshold, it is determined as a non-flat surface.

[0075] That is, by directly calculating the standard deviation in the region, the determination of whether it is flat can be obtained, and by connecting the neighborhood region, the flat region and the non-flat region in the second region can be obtained.

[0076] Similarly, if the second region is a flat surface, assuming that the area of the second region is S2, the required covering agent volume V2 and the corresponding covering agent mass m2 can also be estimated in a manner similar to step S22 described above.

[0077] In addition, if the second region is a non-flat surface, traverse the point cloud data of the second region, compare the z coordinate value of each point. Initialize a variable z min to a large value (for example, it can be set to the upper limit of the initial design height of the electrolytic aluminum tank), and then for each point, if it is less than z min , update z min , and record the corresponding point coordinates at the same time, until the low point of the second region is found after traversal.

[0078] By the low point, the covering agent thickness threshold, and then by the triangulation method or the area estimation method based on point cloud density, or by the integral method, the required covering agent volume V3 and the corresponding covering agent mass m3 required are obtained. It should be noted that the covering agent volume V3 includes two parts of the recess and the surface of the second region to the covering agent thickness threshold.

[0079] Continue to refer to Figure 3 , in a specific preferred scheme, the low point of the second region is used to calculate the covering agent requirement amount according to the low point and the covering agent thickness threshold, which comprises:

[0080] Step S251, traverse all point cloud data in the second region to obtain the minimum height value and the maximum height value;

[0081] Step S252, perform point cloud volume calculation in the bounding box from the minimum height value to the maximum height value in the second region to obtain the second region point cloud volume, and subtract the second region point cloud volume from the bounding box volume to calculate the first demand amount;

[0082] Step S253, based on the second difference value of the maximum height value and the covering agent thickness threshold, to calculate the second demand amount;

[0083] Step S254, accumulate the first demand amount and the second demand amount to obtain the covering agent demand amount.

[0084] It can be understood that by traversing all points, the minimum and maximum values of the height (z coordinate) are found. These two values define a range in the vertical direction. According to the lowest point and the highest point obtained in step S251, a "cuboid box" can be constructed to completely wrap the point cloud in the second region. The volume of this box is the bounding box volume, and the calculation formula is: bounding box volume = (x direction length) × (y direction length) × (z direction height difference); The approximate method is used to count how many points are in the bounding box, and then the actual volume occupied by the point cloud is estimated according to the density or distribution characteristics of the points. The "empty" part of the bounding box volume minus the actual volume of the point cloud is obtained. This part of the gap needs to be filled with covering agent, so it is the first demand amount.

[0085] The covering agent not only fills the gap, but also lays a layer of specified thickness on the surface of the electrolytic aluminum liquid. The covering agent thickness needed to be laid on the surface is obtained by subtracting the "height maximum value" from the "height maximum value + covering agent thickness threshold" (i.e. the threshold itself). As above, the projection area of the second region in the horizontal plane (xy plane) is calculated, and the covering agent thickness is multiplied to obtain the volume required for surface laying, i.e. the second demand amount = (horizontal projection area) × (covering agent thickness threshold). Add the results of step S252 (gap filling amount) and step S253 (surface laying amount) to obtain the total covering agent volume V3 required for the covering agent, and similarly the corresponding covering agent demand amount mass m3 can be derived through the covering agent density.

[0086] In summary, the above method considers the gap filling inside the region (such as the recessed part), and also considers the uniform laying on the surface to ensure that the covering agent is sufficient. By using the difference between the bounding box and the point cloud volume, the direct calculation of the internal gap volume of the complex shape is avoided, and the efficiency is improved.

[0087] In the above step S30, the feeding path is generated in the covering area, and the covering agent is automatically added by the covering agent demand amount by controlling the crown to drive the rigid cloth pipe according to the feeding path, including:

[0088] Step S31, when the first area or the second area is a flat surface, the Z-shaped route is adopted for the covering agent addition;

[0089] Step S32, when the second area is a non-flat surface, the low point is first supplemented and then the Z-shaped route is adopted for the covering agent addition.

[0090] It can be understood that, when the first area or the second area is a flat surface, the crane drives the cloth pipe to move back and forth in parallel line segments within the area range (such as from left to right and then from right to left), to ensure uniform distribution of the covering agent; and when the surface is non-flat, the crane is moved above the low point determined according to step S251, and the cloth pipe is used to supplement the additional covering agent at the low point, to ensure that the recessed area tends to be filled, and after the supplement, the overall surface is close to flat, and the remaining covering agent is uniformly distributed according to the Z-shaped route. Through the above, the flat area is efficiently covered, and the non-flat area is accurately supplemented, to avoid waste or insufficient coverage. The path generation and cloth control are completely calculated by the system, to reduce manual intervention, and the Z-shaped route ensures uniform distribution of the covering agent, and the point supplement solves the problem of local recess.

[0091] In step S50, the flatness of the second covering agent surface is fitted, and the supplement area is obtained, and the crane is controlled to drive the rigid cloth pipe to supplement the supplement area in turn until the flatness meets the preset flatness threshold, including:

[0092] Step S51, a least square fitting plane is obtained for the second covering agent surface;

[0093] Step S52, the maximum distance and the minimum distance of the points of the second covering agent surface to the least square fitting plane are calculated, and the difference between the maximum distance and the minimum distance is taken as the flatness;

[0094] Step S53, the area of the second covering agent surface below the height of the least square fitting plane is taken as the supplement area, and when the flatness is greater than the preset flatness threshold, the crane is controlled to drive the rigid cloth pipe to supplement the supplement area in turn;

[0095] Step S54, the flatness is calculated again after each round of supplement is completed, and if the flatness is still greater than the flatness threshold, the crane is controlled to drive the rigid cloth pipe to supplement the supplement area in turn until the flatness is less than the flatness threshold.

[0096] The point cloud data of the surface of the second covering agent is fitted with a best plane by least square method, and the plane represents the "ideal flatness" of the current covering agent surface as a reference for subsequent flatness calculation. For each point on the surface of the covering agent, the vertical distance of the point to the fitted plane is calculated, and the maximum value (the highest point deviation) and the minimum value (the lowest point deviation) of the distance of all points to the fitted plane are found. In this application, the flatness is equal to the maximum distance minus the minimum distance. Otherwise, the area below the fitted plane (i.e. the point cloud height < the height of the fitted plane) is defined as a concave area, and the covering agent needs to be added. If the current flatness is greater than the preset threshold (such as 5mm), it means that the surface is not flat and needs to be added. The crane moves the cloth pipe over the concave area and quantitatively deposits the covering agent. The amount of each addition is relatively small.

[0097] After adding the covering agent, the surface point cloud is scanned again, the fitted plane and the flatness are updated, and if the flatness is still greater than the flatness threshold, step S53 is repeated to continue adding the concave area. If the flatness is less than the threshold, stop adding. At this time, the surface flatness has reached the standard.

[0098] The application gradually approaches the flatness target through multiple small-scale quantitative additions, avoiding one-time excessive deposition. From the fitted plane to the addition and verification, the whole process does not require manual intervention.

[0099] The application also sets a "maximum allowed height". After each round of addition is completed, if the flatness is still greater than the flatness threshold and the height of the least square fitted plane has exceeded the maximum allowed height, the next round of addition operation is stopped and a warning is prompted.

[0100] As Figure 4 , the application also provides an automatic covering agent adding system for a crane in an aluminum electrolysis workshop. The automatic covering agent adding system 100 includes a crane 10, a laser radar scanner 20, a rigid cloth pipe 30, and a controller 40. The laser radar scanner 20 is connected to the crane 10 and is used to scan the aluminum electrolysis tank. The rigid cloth pipe 30 is connected to the crane and is used to release the covering agent. The controller 40 electrically controls the crane 10, the laser radar scanner 20, and the rigid cloth pipe 30. The controller is configured to perform the above-mentioned automatic covering agent adding method for a crane in an aluminum electrolysis workshop.

[0101] Further, the rigid cloth pipe includes a control valve (not shown in the figure) for controlling the opening or closing of the covering agent release. The controller 40 is further configured to control the crane to automatically add the covering agent according to the feeding path and the covering agent demand amount, and the flow rate of the rigid cloth pipe is constant per unit time. The running speed and / or the residence time of the crane are calculated according to the covering agent demand amount to control the covering agent demand amount.

[0102] Any of the technical features described above can be combined. Although not all possible combinations of the technical features are described, any combination of the technical features should be considered as being covered by the present specification, as long as such a combination does not result in a contradiction.

[0103] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still adjust the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part or all of the technical features; and these adjustments or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop, characterized in that: include: Scanning the aluminum electrolytic cell and segmenting it using a plane segmentation model to obtain the surface of the aluminum electrolytic solution and the surface of the first covering agent, and calculating the surface height of the aluminum electrolytic solution; Dividing the entire aluminum electrolytic cell into a plurality of covering areas based on the surface of the electrolytic aluminum liquid and the surface of the first covering agent, and obtaining a covering agent requirement for each of the covering areas based on the received covering agent thickness threshold, the surface height, and the surface of the first covering agent; Generating a feeding path in the covering area, and controlling the overhead crane to drive the rigid material distribution pipe to automatically add the covering agent according to the feeding path and the required amount of the covering agent; After completing the covering agent adding process under the feeding path, the aluminum electrolytic cell is scanned again to obtain the second covering agent surface; The flatness of the second covering agent surface is fitted and the supplementary area is obtained, and the overhead crane is controlled again to drive the rigid material distribution pipe to sequentially supplement the supplementary area until the flatness meets a preset flatness threshold.

2. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 1, characterized in that: The scanning of the electrolytic aluminum tank and segmentation using a plane segmentation model to obtain the surface of the electrolytic aluminum liquid and the surface of the first covering agent, and calculating the surface height of the electrolytic aluminum liquid surface, includes: Roughly segmenting the target point cloud from the scanned 3D data of the electrolytic aluminum tank within a preset height range; Selecting a reference point in the target point cloud and constructing a first vector and a second vector from two points in a neighborhood of the reference point respectively; Obtaining a normalized plane normal vector by calculating the cross product of the first vector and the second vector; Fitting an initial plane model based on the initially calculated plane normal vector and the calculated distance parameter; Calculate the point cloud distance from the target point cloud to the initial plane, and select points whose point cloud distance is less than the preset distance threshold as inliers; Recalculate the vectors and normal vectors based on the set of interior points to fit a new plane model, and repeatedly select the reference points to execute the preset number of times. The plane model with the largest number of interior points is retained as the optimal solution for the electrolytic aluminum liquid surface. Calculating the average height of the inner point set on the surface of the electrolytic aluminum liquid as the surface height of the electrolytic aluminum liquid; Point cloud segmentation is performed on the surface of the electrolytic aluminum liquid to obtain the first covering agent surface.

3. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 1, characterized in that: The step of dividing the entire aluminum electrolytic cell into a plurality of covering areas based on the surface of the aluminum electrolytic solution and the surface of the covering agent, and obtaining the covering agent requirement for each covering area according to the received covering agent thickness threshold, the surface height, and the first covering agent surface, includes: Marking the surface of the electrolytic aluminum liquid as a first area, and marking the surface of the first covering agent as a second area; In the first area, calculating a required amount of covering agent based on a height difference between the surface height and the covering agent thickness threshold; In the second area, determining whether the second area is a flat surface; If the second area is a flat surface, calculating the required amount of covering agent according to the height difference between the average height of the second area and the threshold value of the covering agent thickness; If the second region is a non-flat surface, the required amount of the covering agent is calculated according to the low point of the second region, the low point, and a covering agent thickness threshold.

4. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 3, characterized in that: The determining whether the second area is a flat surface includes: For each point cloud in the second area, query its neighborhood within a preset constraint radius; The height standard deviation in the neighborhood is calculated. If the height standard deviation is less than a preset standard deviation threshold, it is determined to be a flat surface; if the height standard deviation is greater than the preset standard deviation threshold, it is determined to be a non-flat surface.

5. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 3, characterized in that: Calculating the required amount of covering agent according to the low point of the second area and the covering agent thickness threshold includes: Traverse all point cloud data in the second area and obtain the minimum and maximum heights; Calculating the point cloud volume within a bounding box from the minimum height to the maximum height in the second area to obtain the point cloud volume of the second area, and subtracting the point cloud volume of the second area from the bounding box volume to calculate the first demand; calculating a second required amount based on a second difference between the maximum height and the cover material thickness threshold; The first requirement and the second requirement are accumulated to obtain a covering agent requirement.

6. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 3, characterized in that: Generate a feeding path in the covering area, and control the overhead crane to drive the rigid material distribution pipe to automatically add the covering agent according to the feeding path and the required amount of covering agent, including: In the first area or the second area which is a flat surface, the covering agent is added in a Z-shaped route; In the second area of ​​the non-flat surface, the fixed-point feeding is first performed at the low point and then the covering agent is added in a Z-shaped route.

7. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 3, characterized in that: The step of fitting the flatness of the second covering agent surface and obtaining a supplementary area, and controlling the overhead crane again to drive the rigid material distribution pipe to sequentially add material to the supplementary area until the flatness meets a preset flatness threshold, includes: Obtaining a least square fitting plane on the surface of the second covering agent; Calculating the maximum distance and the minimum distance from a point on the surface of the second covering agent to the least squares fitting plane, and taking the difference between the maximum distance and the minimum distance as the flatness; The area on the surface of the second covering agent that is lower than the height of the least square fitting plane is used as a supplementary area, and when the flatness is greater than a preset flatness threshold, the overhead crane is controlled to drive the rigid distribution pipe to quantitatively add to the supplementary area in sequence; After each round of addition is completed, the flatness is calculated again. If the flatness is still greater than the flatness threshold, the overhead crane is controlled cyclically to drive the rigid material distribution pipe to add quantitatively to the addition area in sequence until the flatness is less than the flatness threshold.

8. The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop according to claim 7, characterized in that: The method for automatically adding covering agent to an overhead crane in an electrolytic aluminum workshop further comprises: After each round of addition is completed, if the flatness is still greater than the flatness threshold and the height of the least squares fitting plane has exceeded the maximum allowable height, the addition is stopped and an alarm is issued.

9. An automatic covering agent adding system for overhead crane in electrolytic aluminum workshop, characterized in that: include: Overhead crane; A laser radar scanner connected to the overhead crane for scanning the electrolytic aluminum cell; a rigid material distributing pipe connected to the overhead crane and used for distributing the covering agent; A controller electrically controls an overhead crane, a light radar scanner, and a rigid material distribution pipe, wherein the controller is configured to execute the method for automatically adding a covering agent to an overhead crane in an electrolytic aluminum workshop as described in any one of claims 1 to 9.

10. The automatic covering agent adding system for overhead crane in electrolytic aluminum workshop according to claim 9 is characterized in that: The rigid material distribution pipe includes a control valve, and the control valve is used to control the opening or closing of the covering agent release; The controller is further configured to: When controlling the overhead crane to drive the rigid distribution pipe to automatically add covering agent according to the feeding path and the covering agent demand, the flow rate per unit time of the rigid distribution pipe is constant, and the operating speed and / or residence time of the overhead crane is calculated according to the covering agent demand to control the covering agent demand.

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