A part lifting point determination method, device, system and lifting equipment

Abstract

The application discloses a part lifting point determination method, device, system and lifting equipment, and belongs to the field of automation. The method automatically ensures that the resultant force action line accurately passes through the supporting geometric center during lifting through the properties of the part itself, fundamentally eliminating the risk of part overturning. For symmetrical parts, the method uses vector translation to achieve rapid positioning. For asymmetrical parts, the mass lever ratio model is introduced, so that the lifting point automatically adjusts the moment balance according to the mass distribution, perfectly solving the eccentric problem. At the same time, the method dynamically decides to use two-point or four-point lifting through threshold judgment, achieving an optimal balance between safety and economy, and can adapt to complex conditions such as inclined lifting through projection and back projection strategies. The application does not require manual line drawing or trial lifting, has high automation, can be widely integrated into intelligent lifting equipment, and significantly reduces the dependence on operating experience.

Description

Technical Field

[0001] This application relates to the field of automation technology, and in particular to a method, apparatus, system and lifting equipment for determining the lifting point of a part. Background Technology

[0002] In the mold manufacturing, processing, and assembly process, the handling and hoisting of large or heavy mold parts are critical technological steps. Traditional hoisting methods mainly rely on the experience and judgment of operators, achieving lifting balance through repeated trial lifts and manual adjustments of the lifting point position. This method is inefficient, labor-intensive, and prone to causing parts to tilt or sway during hoisting due to shifts in the center of gravity, posing serious safety hazards. Some existing technologies attempt to calculate the geometric center or center of mass of the part using 3D modeling software and set a single lifting point directly above the center of mass. However, for mold parts with complex shapes and uneven mass distribution (such as those with deep cavities, reinforcing ribs, slider grooves, cooling channels, etc.), their physical center of mass is not the geometric center, and a single lifting point cannot guarantee the stability of the lifting posture, and overturning or twisting may still occur.

[0003] Furthermore, existing technologies lack automated support for multi-point balanced lifting, and cannot automatically generate two-point or multi-point lifting coordinates that meet the torque balance conditions based on the lifting surface specified by the user. More importantly, there are currently no automated tools integrated into mainstream 3D design platforms (such as Siemens NX) that can complete intelligent planning of lifting points during the design phase.

[0004] Therefore, there is an urgent need for a system and method that can directly calculate the centroid based on the solid properties in a 3D modeling environment, and automatically generate a two-point or multi-point lifting scheme that meets the mechanical equilibrium conditions by combining the user-specified lifting surface and reference points, so as to improve the safety, accuracy and design efficiency of lifting operations. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, this application provides a method, device, system and lifting equipment for determining the lifting point of a part, so as to solve the problem that the existing mold design and lifting technology can only provide a single lifting point or rely on manual experience to set the lifting point, which makes it impossible to achieve stable and balanced lifting of complex mold parts with obvious center of gravity offset.

[0006] The technical solution adopted by this application to solve its technical problem is: Firstly, a method for determining the lifting point of a part is provided, including: Determine the center of gravity of the part to be lifted; Obtain the projection point of the centroid on the lifting surface; The remaining lifting points are determined based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

[0007] As an optional implementation of this application, it further includes: if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is symmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: Calculate the target vector from the first lifting point to the projection point; The second lifting point is determined based on the target vector and the projection point, and the coordinates of the second lifting point are the sum of the coordinates of the projection point and the corresponding coordinates of the target vector.

[0008] As an optional implementation of this application, it further includes: if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is asymmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: The part to be lifted is divided into a first part and a second part by a target plane, wherein the target plane is perpendicular to the lifting surface and passes through the target straight line, and the first part is the part in the direction of the first lifting point; The first mass of the first part and the second mass of the second part of the part to be lifted are obtained respectively. A second lifting point is determined based on the first mass and the second mass, wherein the projection point is located on the line connecting the second lifting point and the first lifting point, and the first distance / second distance = second mass / first mass, wherein the first distance is the distance from the first lifting point to the projection point, and the second distance is the distance from the second lifting point to the projection point.

[0009] As an optional implementation of this application, it further includes: if the lifting surface is parallel to the horizontal plane, and a four-point lifting method is used and the part to be lifted has at least two axes of symmetry, and the two axes of symmetry are perpendicular to each other, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: A rectangle is defined on the lifting surface with the first lifting point as one vertex and the projection point as the center. The sides of the rectangle are parallel to the X-coordinate axis and the Y-coordinate axis, respectively, and the directions of the X-coordinate axis and the Y-coordinate axis are the same as the directions of the two axes of symmetry. Use the other vertices of the rectangle as the remaining lifting points.

[0010] As an optional implementation of this application, it also includes: If the lifting surface forms an angle with the horizontal plane, determining the remaining lifting points based on the first lifting point and the projection point includes: First, project the lifting surface onto a horizontal plane to obtain the projected lifting surface; The remaining lifting points on the projected lifting surface are determined based on the projected lifting surface and the first lifting point; The remaining lifting points are obtained by projecting the remaining lifting points on the projection lifting surface back onto the lifting surface.

[0011] As an optional implementation of this application, it also includes: When the part to be lifted has at least two axes of symmetry and the two axes of symmetry are perpendicular to each other, calculate the offset of the projection point from the geometric center of the lifting surface; Obtain the diagonal length of the lifting surface; When the ratio of the offset to the diagonal length is greater than a threshold, four-point lifting is determined; when the ratio of the offset to the diagonal length is less than or equal to the threshold, two-point lifting is determined.

[0012] As an optional implementation of this application, determining the center of gravity of the part to be lifted includes: Obtain the physical properties of the part to be lifted, including volume, mass, and density; The center of mass of the part to be lifted is determined based on its physical properties.

[0013] Secondly, a device for determining the lifting point of a part is provided, comprising: The center of gravity determination module is used to determine the center of gravity of the part to be lifted. The projection point determination module is used to obtain the projection point of the center of mass on the lifting surface; The lifting point determination module is used to determine the remaining lifting points based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

[0014] Thirdly, a system for determining the lifting point of a part is provided, including: At least one processor and at least one memory; The memory stores the executable instructions of the processor; The processor is configured to perform the part lifting point determination method described in any of the preceding descriptions.

[0015] Fourthly, a lifting device is provided, including the aforementioned part lifting point determination system.

[0016] Beneficial effects: This application provides a method, apparatus, system, and lifting equipment for determining the lifting point of a part. By forcibly constraining the projection point of the center of mass of the part to be lifted onto the lifting surface to the line connecting the first lifting point and any remaining lifting point, it mechanically ensures that the line of action of gravity accurately passes through the geometric center of the lifting support area during lifting, thereby completely eliminating the risk of tipping or tilting caused by center of mass offset, and significantly improving the safety and stability of the lifting operation. Simultaneously, this solution replaces the traditional repeated trial lifting process relying on manual experience with a clear geometric relationship. The calculation logic is clear and easy to program, simplifying the process of determining the lifting point and providing a reliable mathematical benchmark for subsequent automated lifting control. This method is particularly suitable for complex parts with irregular shapes or uneven mass distribution, effectively reducing reliance on operator experience. It has outstanding advantages of convenient operation, strong adaptability, and high safety and reliability, providing a scientific, efficient, and universal solution for the industrial lifting field. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a method for determining the lifting point of a part provided in an embodiment of this application; Figure 2 This is a flowchart of a method for determining the lifting point using a two-point lifting method with parallel lifting surfaces, provided in an embodiment of this application. Figure 3 This is a flowchart of another lifting point determination method provided in this application embodiment, where the lifting surfaces are parallel and a two-point lifting method is used; Figure 4 This is a flowchart of a method for determining lifting points using a four-point lifting method with parallel lifting surfaces, provided in an embodiment of this application. Figure 5 This application provides a method for determining a lifting point where the lifting surface forms an angle with the horizontal plane. Figure 6 This is a flowchart illustrating an automatic method for determining a lifting mechanism, as provided in an embodiment of this application. Figure 7 This is a schematic diagram of an automatic lifting device structure provided in an embodiment of this application; Figure 8 This is a schematic diagram of an automatic lifting system structure provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Existing mold design and hoisting technologies can only provide a single hoisting point or rely on manual experience to set the hoisting point, which leads to the technical problem that it is impossible to achieve stable and balanced hoisting of complex mold parts with significant center of gravity offset. At the same time, it solves the technical problem that it is impossible to automatically calculate and generate a second balance hoisting point that meets the torque balance condition based on the hoisting reference plane specified by the user, thus making it difficult to ensure that the part maintains a horizontal posture after hoisting.

[0021] To solve the above problems, refer to Figure 1 This application provides a method for determining the lifting point of a part, including: S11: Determine the center of gravity of the part to be lifted; In a preferred implementation of this application, the center of gravity of the part to be lifted is obtained in the following way: Obtain the physical properties of the part to be lifted, including volume, mass, and density; The center of mass of the part to be lifted is determined based on its physical properties.

[0022] In one embodiment, it is determined manually through manual calculation.

[0023] In another embodiment, a 3D model of the part to be lifted is imported into existing software such as UG NX. The centroid is then obtained based on physical properties using existing tools.

[0024] S12: Obtain the projection point of the centroid on the lifting surface; In one embodiment, the lifting surface is manually selected by the user.

[0025] In another embodiment, the geometry of the part to be lifted is automatically determined. For example: Obtain the surface area of ​​each face of the part to be lifted; The surface with the largest surface area will be used as the lifting surface.

[0026] In practical applications, if there are multiple surfaces with the largest surface area, the lifting surface can be determined based on the angle between it and the horizontal plane. The smaller the angle, the higher its priority.

[0027] Prioritize using a surface parallel to the horizontal plane as the lifting surface. From a physics and mechanics perspective, during lifting, the external force (tension of the lifting rope) is vertically upward, while gravity is vertically downward. If the lifting surface is parallel to the horizontal plane, all lifting points are at the same horizontal height. At the moment of lifting, the tension and gravity are completely collinear, preventing the generation of additional horizontal forces. The part can rise smoothly and vertically, effectively avoiding swaying or rotation caused by these forces, thus maximizing safety. Conversely, if the lifting surface is tilted, the lifting points will be at different heights. During lifting, the direction of the rope tension will be at an angle to the direction of gravity, generating horizontal forces. This can easily cause the part to sway in the air and may also lead to the risk of tipping over due to uneven local stress.

[0028] From a computational geometry perspective, when the lifting surface is horizontal, this plane is considered a horizontal plane, and the projection of the centroid is its orthogonal projection in the vertical direction. This eliminates the need for complex spatial coordinate rotations or trigonometric transformations, making subsequent vector calculations more direct and concise, with less error accumulation. This helps ensure the accuracy of the lifting point positioning and the efficiency of the algorithm execution. Therefore, choosing a horizontal plane from among multiple planes with the largest area is the optimal strategy that balances engineering safety and algorithm robustness.

[0029] If there are multiple surfaces with the largest surface area, all parallel to the horizontal plane, then the selection is based on priority from top to bottom. When the part is in its normal placement position, the upper surface is completely exposed and unobstructed, making it easy for workers to place lifting lugs, magnetic chucks, or securing ropes. However, the lower surface is usually in close contact with the ground, support frame, or tooling platform, resulting in a narrow working space and making it difficult to reach into lifting equipment or secure lifting connectors. Forcibly lifting from the bottom requires flipping or jacking, increasing auxiliary procedures and operational difficulty.

[0030] S13: Determine the remaining lifting points based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

[0031] First, it should be noted that the first lifting point can be manually selected by the user, or it can be automatically determined based on the geometry of the lifting surface. For example, it can iterate through all discrete points or feature vertices on the lifting surface contour, calculate the distance from each point to the centroid projection point, select the boundary point with the farthest distance that is connected to the projection point as the target line segment, and then select a point on the target line segment as the first lifting point. It is necessary to ensure that the remaining lifting points can be obtained when lifting at two or four points.

[0032] This strategy can maximize the length of the line connecting the two points, ensuring that the projection point is likely to be located within the line interval, and the far end of the lifting point is convenient for setting up the traction rope, which is beneficial for attitude control in the initial stage of lifting.

[0033] Example 1:

[0034] like Figure 2 As shown, if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is symmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: Calculate the target vector from the first lifting point to the projection point; The second lifting point is determined based on the target vector and the projection point, and the coordinates of the second lifting point are the sum of the coordinates of the projection point and the corresponding coordinates of the target vector.

[0035] Example 1 utilizes the symmetry of the target line to determine the second lifting point using only simple vector addition, resulting in extremely low computational cost, rapid response, and no need for iterative solutions. Furthermore, this scheme ensures that the first and second lifting points are strictly symmetrical about the center of mass projection point, guaranteeing complete force balance at both points. This fundamentally guarantees the stability and safety of the lifting process for symmetrical parts, making it particularly suitable for real-time or batch-based automatic lifting scheme generation scenarios.

[0036] Example 2:

[0037] like Figure 3 As shown, if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is asymmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: The part to be lifted is divided into a first part and a second part by a target plane, wherein the target plane is perpendicular to the lifting surface and passes through the target straight line, and the first part is the part in the direction of the first lifting point; The first mass of the first part and the second mass of the second part of the part to be lifted are obtained respectively. A second lifting point is determined based on the first mass and the second mass, wherein the projection point is located on the line connecting the second lifting point and the first lifting point, and the first distance / second distance = second mass / first mass, wherein the first distance is the distance from the first lifting point to the projection point, and the second distance is the distance from the second lifting point to the projection point.

[0038] Example 2, for asymmetrical parts, creatively introduces a mass-lever ratio model. The part is divided into two parts by a target plane, and the masses of each part are obtained. The second lifting point is determined based on the inverse relationship of "first distance / second distance = second mass / first mass". This scheme ensures that the center of mass projection is precisely located on the line connecting the two lifting points, achieving optimal torque balance based on the actual mass distribution. It perfectly solves the industry problem of unstable lifting of eccentric parts, significantly improving the accuracy and safety of lifting irregularly shaped structures.

[0039] Example 3:

[0040] like Figure 4 As shown, if the lifting surface is parallel to the horizontal plane: When a four-point lifting method is used and the part to be lifted has at least two axes of symmetry, and the two axes of symmetry are perpendicular to each other, determining the remaining lifting points based on the first lifting point and the projection point includes: A rectangle is defined on the lifting surface with the first lifting point as one vertex and the projection point as the center. The sides of the rectangle are parallel to the X-coordinate axis and the Y-coordinate axis, respectively, and the directions of the X-coordinate axis and the Y-coordinate axis are the same as the directions of the two axes of symmetry. Use the other vertices of the rectangle as the remaining lifting points.

[0041] Example 3 addresses large parts with two mutually perpendicular axes of symmetry. A four-point lifting method is employed, constructing a rectangle centered on the centroid projection point, with the other three vertices serving as the remaining lifting points. This method ensures that the four lifting points are perfectly symmetrically distributed about the centroid projection, resulting in uniform force distribution and reasonable load allocation, effectively preventing deformation or damage to the part due to localized overload. Simultaneously, the four-point support significantly improves torsional stability during lifting, making it particularly suitable for the stable lifting of large, thin-walled, or easily deformable parts.

[0042] Example 4:

[0043] like Figure 5 As shown, it also includes: If the lifting surface forms an angle with the horizontal plane, determining the remaining lifting points based on the first lifting point and the projection point includes: The lifting surface is projected onto a horizontal plane to obtain the projected lifting surface; The remaining lifting points on the projected lifting surface are determined based on the projected lifting surface and the first lifting point. The specific determination method adopts any one of the above embodiments 1-3. The remaining lifting points are obtained by projecting the remaining lifting points on the projection lifting surface back onto the lifting surface.

[0044] Example 4 addresses the complex condition of an inclined lifting surface. It calculates the lifting point by projecting the inclined lifting surface onto a horizontal plane, and then backprojecting the result back onto the original lifting surface, cleverly reducing the three-dimensional spatial problem to a mature two-dimensional planar problem. This solution eliminates the need to develop a dedicated algorithm for inclined conditions, directly reusing the solution logic from the aforementioned examples. It possesses strong versatility and adaptability. Furthermore, the geometric transformation between projection and backprojection ensures the accuracy of coordinate mapping, effectively expanding the engineering applicability of this lifting point determination method.

[0045] In some embodiments, the user can manually select whether to use two-point lifting or four-point lifting.

[0046] In other embodiments, whether to use two-point or four-point lifting is determined by the properties of the part to be lifted, such as whether it is regular (e.g., whether it has an axis of symmetry; if not, two-point lifting is used) and the ratio of its maximum length (e.g., length along the X-axis) to its maximum width (e.g., width along the Y-axis) projected onto the horizontal plane. Two-point lifting is used when the ratio is not within a preset range. A ratio outside the preset range indicates that the part is elongated; for this part, there is little difference between four-point and two-point lifting. However, two-point lifting is simpler in terms of calculation and operation.

[0047] As a preferred implementation of the embodiments of this application, such as Figure 6 As shown, it also includes: When the part to be lifted has at least two axes of symmetry and the two axes of symmetry are perpendicular to each other, calculate the offset of the projection point from the geometric center of the lifting surface; Obtain the diagonal length of the lifting surface; When the ratio of the offset to the diagonal length is greater than a threshold, four-point lifting is determined; when the ratio of the offset to the diagonal length is less than or equal to the threshold, two-point lifting is determined.

[0048] This application's solution calculates the offset between the centroid projection point and the geometric center of the lifting surface, and establishes a ratio threshold judgment mechanism based on the diagonal length of the lifting surface, thus achieving intelligent dynamic decision-making regarding the number of lifting points. When the offset is large, four-point lifting is automatically adopted to ensure sufficient safety redundancy and anti-overturning capability; when the offset is small, two-point lifting is adopted to simplify operation and reduce costs. This mechanism achieves an optimal balance between safety and economy, avoiding the subjectivity and arbitrariness of manual selection based on experience, and significantly improving the scientific nature and adaptability of lifting scheme formulation.

[0049] It should be emphasized that this application targets parts with uniform density.

[0050] It should be noted that any process or method description in the flowchart or otherwise described herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as should be understood by those skilled in the art to which the embodiments of this application pertain.

[0051] Furthermore, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0052] The part lifting point determination method provided in this application accurately calculates the part's center of mass and its projection point on the lifting surface, and forcibly constrains this projection point to lie on the line connecting the first lifting point and the remaining lifting points. This mechanically ensures that the line of action of gravity precisely passes through the geometric center of the lifting support area, completely eliminating the risk of overturning caused by center of mass shift. For different working conditions, this method provides diverse solutions: for symmetrical parts, vector translation is used for rapid positioning; for asymmetrical parts, a mass-lever ratio model is introduced for precise counterweighting; and for inclined lifting surfaces, projection and back-projection strategies simplify the three-dimensional problem into two-dimensional calculations. Simultaneously, by judging the threshold of the ratio of offset to diagonal length, intelligent decision-making adopts two-point or four-point lifting, achieving a dynamic optimal balance between safety and economy. This method eliminates the need for manual line drawing or repeated trial lifting, boasts a high degree of automation, simple calculation, and strong applicability, and can be widely applied in high-end equipment fields such as aerospace and shipbuilding, significantly improving the safety, efficiency, and intelligence level of lifting operations.

[0053] To more clearly illustrate the solution proposed in this application, a specific implementation method is provided below: This embodiment uses Siemens NX 11.0 as the development environment. UG secondary development is a set of tools for developing extended functions of UGNX 3D design software, including UG / OPEN API toolset, UG_GRIP, etc. The former is an object-oriented development tool based on C++, and the latter is a simple procedural development tool. The program is the process of the inventor realizing independent development from scratch.

[0054] Step S1: Environment initialization and data loading.

[0055] Launch UG NX software and load the application (DLL module) implementing this application. The user opens the 3D assembly or part file containing the mold parts to be machined. Ensure the parts have been converted to Solid Body format, as centroid calculations require a closed 3D solid model.

[0056] Step S2: Select the target object and define the baseline.

[0057] First, the program guides the user to select the main body of the mold part whose lifting point needs to be calculated using the mouse (BodySelection). The program then calls API interfaces such as UF_MODL_ask_body_props to read the entity's volume, mass, and other attributes. During this process, the program needs to confirm whether the material's density attribute has been correctly assigned to the entity. If not, the program prompts the user to enter the default density or directly use relative density for normalized calculation (focusing only on the geometric centroid).

[0058] Step S3: Calculate the geometric centroid.

[0059] The program calls the NX Open::Body::Get Mass Properties function, which in turn calls the UG UF_MODL_ask_mass_props_3d() function to obtain the mass properties of a specified entity or sheet, requiring the unit and density value to be specified.

[0060] If not specified, the default density of general-purpose steel, 7.85 g / cm³, will be used. 3 The density parameter is passed in to obtain the MassProperties structure entity. The Center Of Mass attribute is extracted from this structure. This attribute is a Point3d object containing the X, Y, and Z coordinates of the centroid in the absolute coordinate system. This coordinate system is labeled C, thus generating the centroid point C(xc, yc, zc) (a function of traditional tools, built into the UG software).

[0061] For example, the centroid coordinates are (20.316750248, 1.089053604, 135.396933865). To facilitate the demonstration of the principle, a simplified model will be used for explanation. The model generates a centroid point C, and the coordinates are taken as integer values ​​(20, 1, 135) for easy calculation.

[0062] Step S4: Define the lifting plane and the first reference point.

[0063] The user is prompted via the UI to select a placement plane (Face object) as the lifting surface. This plane can be any end face of the part.

[0064] The user is then prompted to click a point on the selected lifting surface as the first lifting point P1. The program records the coordinates of P1 in the absolute coordinate system.

[0065] Step S5: Calculate the second lifting point This is the core algorithm of this application. Its principle is: the two lifting points P1 and P2 must be located on the same horizontal plane (lifting plane), and the projection point of the centroid C on the horizontal plane must be located on the line connecting P1 and P2, and the distance from P1 and P2 to the projection point is inversely proportional to the weight they bear.

[0066] Assuming uniform part mass, the distances from P1 and P2 to the projection point should be equal, meaning P2 and P1 are symmetrical about the projection point C_proj. The specific calculation steps are as follows: Obtain the normal vector N of the lifting surface.

[0067] Assuming the lifting surface is horizontal, N is usually parallel to the direction of gravity (e.g., when the Z-axis is upward, N is (0,0,1) or (0,0,-1)).

[0068] Calculate the projection point C_proj of the centroid C on the lifting surface.

[0069] Assume the coordinates of the centroid C obtained through step 2 are (20, 1, 135). The lifting surface is the plane with Z=1. Then the Z coordinate of C_proj should be consistent with the lifting surface, and the X and Y coordinates should be the same as C. Therefore, the coordinates of C_proj are (20, 1, 1).

[0070] Calculate the vector V from P1 to C_proj.

[0071] Suppose the coordinates of the first lifting point P1 clicked by the user on the lifting surface are (20, -365, 1).

[0072] Then the vector V =|C_proj|-|P1|=(20-20, 1+365, 80-80)=(0, 366, 0).

[0073] Calculate the second lifting point P2.

[0074] According to the general torque balance, P2 should satisfy P2 = C_proj + V.

[0075] Substituting the above values, P2 = (20, 1, 1) + |(0, 366, 0)| = (20, 367, 1).

[0076] At this point, the midpoint coordinates of P1 (20, -365, 1) and P2 (20, 367, 1) are ((20+20) / 2, (-365+367) / 2, (1+1) / 2) = (20, 1, 1), which coincides with the centroid projection point C_proj.

[0077] This indicates that the two lifting points are symmetrically distributed on both sides of the center of mass projection, satisfying the torque balance condition (ΣM=0). At this time, if equal vertical upward tension is applied at P1 and P2, the resultant torque is zero, and the part will remain horizontally lifted.

[0078] Step S6: Result Output and Visualization The program visually displays whether P2 is located within the lifting surface selected by the user. In the UG 3D model, points (Point objects) are created at locations P1 and P2, and optional auxiliary lines are created from these two points to the center of mass C to visually demonstrate the balance relationship. Simultaneously, the coordinate values ​​of the two lifting points are displayed in the UI for user reference. Users can directly create lifting rings or lifting point features based on these two points.

[0079] By following the steps above, users only need to perform three simple operations: "select body, select face, and click a point" to automatically complete the dual-point balanced hoisting design of complex mold parts, greatly improving work efficiency and safety.

[0080] The selection plane enables the selection of any surface projection in space or the switching of multiple reference planes, and supports the adjustment of the lifting reference system according to multiple situations and scenarios, as well as the hook height.

[0081] Furthermore, when the mold parts are extremely heavy or have highly irregular structures, this method can be extended to a four-point balanced lifting system. After the user selects the first corner point P1 on the lifting surface, the system automatically calculates the remaining three points P2, P3, and P4 based on the centroid projection C_proj, ensuring that the rectangle formed by the four points has C_proj as its geometric center and that each side is parallel to the coordinate axes or user-defined directions. By solving a system of linear equations, the system ensures that the resultant moment of the four lifting points about the centroid is zero, making it suitable for the overall lifting of large mold frames.

[0082] For example: 1. Determine the rectangle parameters and unknowns: Let the four lifting points be P1, P2, P3, and P4, which are located on the lifting plane Z=1.

[0083] Since the rectangle is centered at C_proj(20,1,1) and its sides are parallel to the coordinate axes, we can define this rectangle using two parameters: W: The half-width of the rectangle in the X direction (i.e., the distance from the center line to the X coordinate of the suspension point).

[0084] H: Half height of the rectangle in the Y direction (i.e., the distance from the Y coordinate of the hanging point to the center line).

[0085] The coordinates of the four suspension points can then be represented as: P1=(20+W,1+H,1) (top right) P2=(20+W,1-H,1) (bottom right) P3=(20-W,1-H,1) (bottom left) P4=(20-W,1+H,1) (top left) At this point, the only unknowns are W and H.

[0086] 2. Establish the system of torque balance equations: To achieve static equilibrium, the sum of the moments generated by the four lifting points must be zero. Assuming each lifting point bears the same ideal uniform load F, it is sufficient to ensure that the geometric center of the lifting point coincides with the projection of the center of mass to achieve zero resultant moment. This is satisfied in the symmetrical structure described above.

[0087] Suppose the user selected point P1, with coordinates (50, 150, 1). Substitute into formula P1: 50 = 20 + W ⇒ W = 30 150 = 1 + H ⇒ H = 149 Therefore, we can solve for W=20 and H=149.

[0088] This leads to the remaining three points: P2=(20+W,1-H,1)=(20+30,1-149,1)=(50,-148,1) P3=(20-W,1-H,1)=(20-30,1-149,1)=(-10,-148,1) P4=(20-W,1+H,1)=(20-30,1+149,1)=(-10,150,1) 3. Verify torque balance: Let C_proj(20,1) be the center of torque. X-direction torque: (50-20)+(50-20)+(-10-20)+(-10-20)=0.

[0089] Torque in the Y direction: (150-1)+(-148-1)+(-148-1)+(150-1)=0.

[0090] The net torque is zero, which satisfies the equilibrium condition.

[0091] In addition, when there is an angle θ between the lifting surface and the horizontal plane (such as inclined lifting), the system will first project the centroid C and the first point P1 onto the horizontal plane, calculate the projection P2_proj of the second point on the horizontal plane, and then back-project it back onto the original lifting surface to ensure that the projection of the line connecting the two lifting points in the horizontal plane passes through the centroid projection, thereby adapting to inclined lifting conditions.

[0092] It should be noted that this invention is not limited to the UG / NX platform, but can also be adapted to other mainstream CAD systems. It can further integrate machine learning modules, collect a large number of lifting ring model samples, expand the lifting ring database, and improve the system's intelligence level.

[0093] Besides NXOpen C++, this method can also be implemented using NXOpen .NET (C# / VB.NET) or the GRIP language. For example, in GRIP, the &MASS statement can be used to obtain the centroid, and the equilibrium point can be determined through geometric calculations. Different implementation methods only affect the code syntax and do not change the core algorithm and scope of protection of this invention.

[0094] The solution provided in this application offers a method for automatic centroid extraction and balanced lifting point calculation based on the UG secondary development interface: It automatically obtains the geometric centroid coordinates of a selected 3D mold part using the UG API (such as UF_MODL_ask_mass_props_3d), combines this with the user-specified lifting plane normal vector, receives one end face of the part selected by the user as the lifting surface, and arbitrarily specifies an initial lifting point on this lifting surface, constructs a spatial coordinate system, and uses the moment balance equation to deduce the coordinates of the second lifting point. Furthermore, the system allows the user to arbitrarily select a first reference point on the lifting surface. Using the centroid projection as a reference, the system automatically calculates the symmetrical or balanced position relative to this reference point as the second lifting point, thus forming a stable lifting axis. This ensures that the plane formed by the two lifting points and the centroid is perpendicular to the direction of gravity, and the sum of the moment vectors of the two lifting points about the centroid is zero, thereby achieving two-point balanced lifting.

[0095] Based on the same inventive concept, such as Figure 7 As shown, this application embodiment provides a part lifting point determination device 70, including: The center of gravity determination module 71 is used to determine the center of gravity of the part to be lifted; In a preferred implementation of this application, the center of gravity of the part to be lifted is obtained in the following way: Obtain the physical properties of the part to be lifted, including volume, mass, and density; The center of mass of the part to be lifted is determined based on its physical properties.

[0096] In one embodiment, it is determined manually through manual calculation.

[0097] In another embodiment, a 3D model of the part to be lifted is imported into existing software such as UG NX. The centroid is then obtained based on physical properties using existing tools.

[0098] Projection point determination module 72 is used to obtain the projection point of the center of mass on the lifting surface; In one embodiment, the lifting surface is manually selected by the user.

[0099] In another embodiment, the geometry of the part to be lifted is automatically determined. For example: Obtain the surface area of ​​each face of the part to be lifted; The surface with the largest surface area will be used as the lifting surface.

[0100] In practical applications, if there are multiple surfaces with the largest surface area, the lifting surface can be determined based on the angle between it and the horizontal plane. The smaller the angle, the higher its priority.

[0101] Prioritize using a surface parallel to the horizontal plane as the lifting surface. From a physics and mechanics perspective, during lifting, the external force (tension of the lifting rope) is vertically upward, while gravity is vertically downward. If the lifting surface is parallel to the horizontal plane, all lifting points are at the same horizontal height. At the moment of lifting, the tension and gravity are completely collinear, preventing the generation of additional horizontal forces. The part can rise smoothly and vertically, effectively avoiding swaying or rotation caused by these forces, thus maximizing safety. Conversely, if the lifting surface is tilted, the lifting points will be at different heights. During lifting, the direction of the rope tension will be at an angle to the direction of gravity, generating horizontal forces. This can easily cause the part to sway in the air and may also lead to the risk of tipping over due to uneven local stress.

[0102] From a computational geometry perspective, when the lifting surface is horizontal, this plane is considered a horizontal plane, and the projection of the centroid is its orthogonal projection in the vertical direction. This eliminates the need for complex spatial coordinate rotations or trigonometric transformations, making subsequent vector calculations more direct and concise, with less error accumulation. This helps ensure the accuracy of the lifting point positioning and the efficiency of the algorithm execution. Therefore, choosing a horizontal plane from among multiple planes with the largest area is the optimal strategy that balances engineering safety and algorithm robustness.

[0103] If there are multiple surfaces with the largest surface area, all parallel to the horizontal plane, then the selection is based on priority from top to bottom. When the part is in its normal placement position, the upper surface is completely exposed and unobstructed, making it easy for workers to place lifting lugs, magnetic chucks, or securing ropes. However, the lower surface is usually in close contact with the ground, support frame, or tooling platform, resulting in a narrow working space and making it difficult to reach into lifting equipment or secure lifting connectors. Forcibly lifting from the bottom requires flipping or jacking, increasing auxiliary procedures and operational difficulty.

[0104] The lifting point determination module 73 is used to determine the remaining lifting points based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

[0105] First, it should be noted that the first lifting point can be manually selected by the user, or it can be automatically determined based on the geometry of the lifting surface. For example, it can iterate through all discrete points or feature vertices on the lifting surface contour, calculate the distance from each point to the centroid projection point, select the boundary point with the farthest distance that is connected to the projection point as the target line segment, and then select a point on the target line segment as the first lifting point. It is necessary to ensure that the remaining lifting points can be obtained when lifting at two or four points.

[0106] This strategy can maximize the length of the line connecting the two points, ensuring that the projection point is likely to be located within the line interval, and the far end of the lifting point is convenient for setting up the traction rope, which is beneficial for attitude control in the initial stage of lifting.

[0107] Example 1:

[0108] like Figure 2 As shown, if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is symmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: Calculate the target vector from the first lifting point to the projection point; The second lifting point is determined based on the target vector and the projection point, and the coordinates of the second lifting point are the sum of the coordinates of the projection point and the corresponding coordinates of the target vector.

[0109] Example 1 utilizes the symmetry of the target line to determine the second lifting point using only simple vector addition, resulting in extremely low computational cost, rapid response, and no need for iterative solutions. Furthermore, this scheme ensures that the first and second lifting points are strictly symmetrical about the center of mass projection point, guaranteeing complete force balance at both points. This fundamentally guarantees the stability and safety of the lifting process for symmetrical parts, making it particularly suitable for real-time or batch-based automatic lifting scheme generation scenarios.

[0110] Example 2:

[0111] like Figure 3 As shown, if the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is asymmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: The part to be lifted is divided into a first part and a second part by a target plane, wherein the target plane is perpendicular to the lifting surface and passes through the target straight line, and the first part is the part in the direction of the first lifting point; The first mass of the first part and the second mass of the second part of the part to be lifted are obtained respectively. A second lifting point is determined based on the first mass and the second mass, wherein the projection point is located on the line connecting the second lifting point and the first lifting point, and the first distance / second distance = second mass / first mass, wherein the first distance is the distance from the first lifting point to the projection point, and the second distance is the distance from the second lifting point to the projection point.

[0112] Example 2, for asymmetrical parts, creatively introduces a mass-lever ratio model. The part is divided into two parts by a target plane, and the masses of each part are obtained. The second lifting point is determined based on the inverse relationship of "first distance / second distance = second mass / first mass". This scheme ensures that the center of mass projection is precisely located on the line connecting the two lifting points, achieving optimal torque balance based on the actual mass distribution. It perfectly solves the industry problem of unstable lifting of eccentric parts, significantly improving the accuracy and safety of lifting irregularly shaped structures.

[0113] Example 3:

[0114] like Figure 4 As shown, if the lifting surface is parallel to the horizontal plane: When a four-point lifting method is used and the part to be lifted has at least two axes of symmetry, and the two axes of symmetry are perpendicular to each other, determining the remaining lifting points based on the first lifting point and the projection point includes: A rectangle is defined on the lifting surface with the first lifting point as one vertex and the projection point as the center. The sides of the rectangle are parallel to the X-coordinate axis and the Y-coordinate axis, respectively, and the directions of the X-coordinate axis and the Y-coordinate axis are the same as the directions of the two axes of symmetry. Use the other vertices of the rectangle as the remaining lifting points.

[0115] Example 3 addresses large parts with two mutually perpendicular axes of symmetry. A four-point lifting method is employed, constructing a rectangle centered on the centroid projection point, with the other three vertices serving as the remaining lifting points. This method ensures that the four lifting points are perfectly symmetrically distributed about the centroid projection, resulting in uniform force distribution and reasonable load allocation, effectively preventing deformation or damage to the part due to localized overload. Simultaneously, the four-point support significantly improves torsional stability during lifting, making it particularly suitable for the stable lifting of large, thin-walled, or easily deformable parts.

[0116] Example 4:

[0117] like Figure 5 As shown, it also includes: If the lifting surface forms an angle with the horizontal plane, determining the remaining lifting points based on the first lifting point and the projection point includes: The lifting surface is projected onto a horizontal plane to obtain the projected lifting surface; The remaining lifting points on the projected lifting surface are determined based on the projected lifting surface and the first lifting point. The specific determination method adopts any one of the above embodiments 1-3. The remaining lifting points are obtained by projecting the remaining lifting points on the projection lifting surface back onto the lifting surface.

[0118] Example 4 addresses the complex condition of an inclined lifting surface. It calculates the lifting point by projecting the inclined lifting surface onto a horizontal plane, and then backprojecting the result back onto the original lifting surface, cleverly reducing the three-dimensional spatial problem to a mature two-dimensional planar problem. This solution eliminates the need to develop a dedicated algorithm for inclined conditions, directly reusing the solution logic from the aforementioned examples. It possesses strong versatility and adaptability. Furthermore, the geometric transformation between projection and backprojection ensures the accuracy of coordinate mapping, effectively expanding the engineering applicability of this lifting point determination method.

[0119] In some embodiments, the user can manually select whether to use two-point lifting or four-point lifting.

[0120] In other embodiments, whether to use two-point or four-point lifting is determined by the properties of the part to be lifted, such as whether it is regular (e.g., whether it has an axis of symmetry; if not, two-point lifting is used) and the ratio of its maximum length (e.g., length along the X-axis) to its maximum width (e.g., width along the Y-axis) projected onto the horizontal plane. Two-point lifting is used when the ratio is not within a preset range. A ratio outside the preset range indicates that the part is elongated; for this part, there is little difference between four-point and two-point lifting. However, two-point lifting is simpler in terms of calculation and operation.

[0121] As a preferred implementation of the embodiments of this application, such as Figure 6 As shown, it also includes: When the part to be lifted has at least two axes of symmetry and the two axes of symmetry are perpendicular to each other, calculate the offset of the projection point from the geometric center of the lifting surface; Obtain the diagonal length of the lifting surface; When the ratio of the offset to the diagonal length is greater than a threshold, four-point lifting is determined; when the ratio of the offset to the diagonal length is less than or equal to the threshold, two-point lifting is determined.

[0122] This application's solution calculates the offset between the centroid projection point and the geometric center of the lifting surface, and establishes a ratio threshold judgment mechanism based on the diagonal length of the lifting surface, thus achieving intelligent dynamic decision-making regarding the number of lifting points. When the offset is large, four-point lifting is automatically adopted to ensure sufficient safety redundancy and anti-overturning capability; when the offset is small, two-point lifting is adopted to simplify operation and reduce costs. This mechanism achieves an optimal balance between safety and economy, avoiding the subjectivity and arbitrariness of manual selection based on experience, and significantly improving the scientific nature and adaptability of lifting scheme formulation.

[0123] The lifting point determination device provided in this application accurately calculates the part's center of mass and its projection point on the lifting surface, and forcibly constrains this projection point to be located on the line connecting the first lifting point and the remaining lifting points. This mechanically ensures that the line of action of gravity precisely passes through the geometric center of the lifting support area, completely eliminating the risk of overturning caused by center of mass shift. For different working conditions, this method provides diverse solutions: for symmetrical parts, vector translation is used for rapid positioning; for asymmetrical parts, a mass-lever ratio model is introduced for precise counterweighting; and for inclined lifting surfaces, projection and back-projection strategies simplify the three-dimensional problem into two-dimensional calculations. Simultaneously, by judging the threshold of the ratio of offset to diagonal length, intelligent decision-making uses two-point or four-point lifting, achieving a dynamic optimal balance between safety and economy. This method eliminates the need for manual line drawing or repeated trial lifting, boasts a high degree of automation, simple calculation, and strong applicability, and can be widely applied in high-end equipment fields such as aerospace and shipbuilding, significantly improving the safety, efficiency, and intelligence level of lifting operations.

[0124] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the part lifting point determination method provided in any of the above embodiments.

[0125] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0126] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0127] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0128] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0129] The computer-readable storage medium provided in this application embodiment stores a computer program, which, when executed by a processor, implements the steps of the part lifting point determination method as provided in any of the above embodiments. This automatically ensures, through the part's own properties, that the line of action of the resultant force accurately passes through the geometric center of the support during lifting, fundamentally eliminating the risk of part overturning. For symmetrical parts, the method uses vector translation for rapid positioning; for asymmetrical parts, a mass-lever ratio model is introduced, allowing the lifting point to automatically adjust the torque balance according to the mass distribution, perfectly solving the eccentricity problem. Simultaneously, the method uses threshold judgment for dynamic decision-making to adopt two-point or four-point lifting, achieving an optimal balance between safety and economy, and can adapt to complex working conditions such as oblique lifting through projection and back-projection strategies. This application eliminates the need for manual line drawing or trial lifting, has a high degree of automation, and can be widely integrated into intelligent lifting equipment, significantly reducing reliance on operational experience.

[0130] Based on the same inventive concept, such as Figure 8 As shown, this application also provides a parts lifting point determination system 80, including: At least one processor 81 and at least one memory 82; The memory stores the executable instructions of the processor; The processor is configured to execute the part lifting point determination method provided in the above embodiments.

[0131] The lifting point determination system for parts provided in this application stores executable instructions for the processor in a memory. When these instructions are executed, the processor automatically ensures that the line of action of the resultant force during lifting precisely passes through the geometric center of the support, based on the part's own properties, fundamentally eliminating the risk of part tipping over. For symmetrical parts, this method uses vector translation for rapid positioning; for asymmetrical parts, a mass-lever ratio model is introduced, allowing the lifting point to automatically adjust the torque balance according to the mass distribution, perfectly solving the eccentricity problem. Simultaneously, this method uses threshold judgment for dynamic decision-making to employ two-point or four-point lifting, achieving an optimal balance between safety and economy, and can adapt to complex working conditions such as oblique lifting through projection and back-projection strategies. This application eliminates the need for manual line drawing or trial lifting, has a high degree of automation, and can be widely integrated into intelligent lifting equipment, significantly reducing reliance on operational experience.

[0132] Based on the same inventive concept, this application provides a lifting device, including the parts lifting point determination system provided in the above embodiments.

[0133] The lifting equipment provided in this application, through the part lifting point determination system provided in the above embodiments, can forcibly constrain the projection point of the center of mass of the part to be lifted onto the lifting surface to the line connecting the first lifting point and any remaining lifting point. This mechanically ensures that the line of action of gravity accurately passes through the geometric center of the lifting support area during lifting, thereby completely eliminating the risk of tipping or tilting caused by center of mass shift, significantly improving the safety and stability of lifting operations. Simultaneously, this solution replaces the traditional repeated trial lifting process relying on manual experience with a clear geometric relationship. The calculation logic is clear and easy to program, simplifying the lifting point determination process and providing a reliable mathematical benchmark for subsequent automated lifting control. This method is particularly suitable for complex parts with irregular shapes or uneven mass distribution, effectively reducing reliance on operator experience. It has outstanding advantages of convenient operation, strong adaptability, and high safety and reliability, providing a scientific, efficient, and universal solution for the industrial lifting field.

[0134] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0135] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0136] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for determining the lifting point of a part, characterized in that, include: Determine the center of gravity of the part to be lifted; Obtain the projection point of the centroid on the lifting surface; The remaining lifting points are determined based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

2. The method according to claim 1, characterized in that, Also includes: If the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is symmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: Calculate the target vector from the first lifting point to the projection point; The second lifting point is determined based on the target vector and the projection point, and the coordinates of the second lifting point are the sum of the coordinates of the projection point and the corresponding coordinates of the target vector.

3. The method according to claim 1, characterized in that: Also includes: If the lifting surface is parallel to the horizontal plane: When a two-point lifting method is used and the part to be lifted is asymmetrical along a target straight line, wherein the target straight line is a straight line on the lifting surface that passes through the projection point and is perpendicular to the line connecting the first lifting point and the projection point, the step of determining the remaining lifting points based on the first lifting point and the projection point includes: The part to be lifted is divided into a first part and a second part by a target plane, wherein the target plane is perpendicular to the lifting surface and passes through the target straight line, and the first part is the part in the direction of the first lifting point; The first mass of the first part and the second mass of the second part of the part to be lifted are obtained respectively. A second lifting point is determined based on the first mass and the second mass, wherein the projection point is located on the line connecting the second lifting point and the first lifting point, and the first distance / second distance = second mass / first mass, wherein the first distance is the distance from the first lifting point to the projection point, and the second distance is the distance from the second lifting point to the projection point.

4. The method according to claim 1, characterized in that, Also includes: If the lifting surface is parallel to the horizontal plane, and a four-point lifting method is used, and the part to be lifted has at least two axes of symmetry, and the two axes of symmetry are perpendicular to each other, the determination of the remaining lifting points based on the first lifting point and the projection point includes: A rectangle is defined on the lifting surface with the first lifting point as one vertex and the projection point as the center. The sides of the rectangle are parallel to the X-coordinate axis and the Y-coordinate axis, respectively, and the directions of the X-coordinate axis and the Y-coordinate axis are the same as the directions of the two axes of symmetry. Use the other vertices of the rectangle as the remaining lifting points.

5. The method according to claim 1, characterized in that, Also includes: If the lifting surface forms an angle with the horizontal plane, determining the remaining lifting points based on the first lifting point and the projection point includes: First, project the lifting surface onto a horizontal plane to obtain the projected lifting surface; The remaining lifting points on the projected lifting surface are determined based on the projected lifting surface and the first lifting point; The remaining lifting points are obtained by projecting the remaining lifting points on the projection lifting surface back onto the lifting surface.

6. The method according to claim 1, characterized in that, Also includes: When the part to be lifted has at least two axes of symmetry and the two axes of symmetry are perpendicular to each other, calculate the offset of the projection point from the geometric center of the lifting surface; Obtain the diagonal length of the lifting surface; When the ratio of the offset to the diagonal length is greater than a threshold, four-point lifting is determined; when the ratio of the offset to the diagonal length is less than or equal to the threshold, two-point lifting is determined.

7. The method according to claim 1, characterized in that: Determining the center of gravity of the part to be lifted includes: Obtain the physical properties of the part to be lifted, including volume, mass, and density; The center of mass of the part to be lifted is determined based on its physical properties.

8. A device for determining the lifting point of a part, characterized in that, include: The center of gravity determination module is used to determine the center of gravity of the part to be lifted. The projection point determination module is used to obtain the projection point of the center of mass on the lifting surface; The lifting point determination module is used to determine the remaining lifting points based on the first lifting point and the projection point, wherein the projection point is located on the line connecting the target lifting point and the first lifting point, and the target lifting point is one of the remaining lifting points.

9. A system for determining the lifting point of a part, characterized in that, include: At least one processor and at least one memory; The memory stores the executable instructions of the processor; The processor is configured to perform the method according to any one of claims 1-7.

10. A lifting device, characterized in that, Includes the part lifting point determination system as described in claim 9.

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