Multi-point adaptive bending compensation method and system for new energy battery tray

Abstract

The application provides a multi-point adaptive bending compensation method and system for a new energy battery tray, which comprises the following steps: reading a three-dimensional model of the battery tray, scanning to generate a springback sensitivity field along a bending line; combining a subsequent welding process to generate a welding deformation tendency field; coupling point by point in the same coordinate system to generate a non-uniform bending-welding collaborative compensation field; determining the pressing compensation amount of each basic body unit of the multi-point mold to generate a non-uniform compensation surface; collecting local counterforce and pressing displacement in the bending process, identifying the material deformation stage and correcting the springback sensitivity field and the welding pre-compensation amount; and implementing differentiated holding pressure and time length according to the above, collaboratively controlling the residual stress, so that the target shape precision is achieved after welding. The application considers the uneven springback and welding deformation caused by local structures such as cooling channels, reinforcing ribs and welds, realizes bending and welding collaborative compensation, and improves the flatness of the tray bottom plate and the perpendicularity of the side wall.

Description

Technical Field

[0001] This invention relates to the field of new energy battery structural component manufacturing technology, and in particular to a multi-point adaptive bending compensation method and system for new energy battery trays. Background Technology

[0002] The battery tray is a core load-bearing and sealing component of the power battery pack. Its bending and forming precision directly affects the battery pack's sealing performance, assembly accuracy, and service life. The battery tray base plate typically features structural features such as cooling channel grooves, reinforcing ribs, mounting holes, and locally thinned areas. When these structures appear near the bending line, they cause extremely uneven stress and strain distribution along the bending line during the bending process. Taking an aluminum alloy battery tray as an example, the cross-section of the cooling channel area is weakened, resulting in decreased local stiffness and a larger springback; conversely, the reinforcing rib area has increased local stiffness and a relatively smaller springback. This uneven springback along the bending line causes a wavy deviation in the tray sidewall angle after bending, which in turn affects the flatness of the base plate and the quality of the welded interface between the sidewall and the base plate.

[0003] After bending, battery trays typically require welding assembly. The heat input during welding induces new angular and shrinkage deformations, and this deformation is uneven along the bending line: areas with concentrated weld seams experience higher heat input and greater deformation tendency; areas with stronger clamping constraints have limited deformation; areas with weakened cross-sections, such as cooling channels, are prone to local instability under welding heat; and areas with reinforcing ribs experience less deformation due to their high local stiffness. If only springback compensation is considered during the bending stage without taking subsequent welding deformation into account, even qualified bent parts may still exhibit non-standard flatness of the sealing surface after welding.

[0004] In existing bending springback compensation technologies, multi-point die surface forming schemes construct compensation surfaces by predicting the curvature changes before and after springback. However, their compensation curvature is calculated based on the overall surface curvature change, without considering the uneven springback caused by local structures. Schemes based on historical bending data or pre-bending detection usually provide a single value or overall correction for the entire bending line, failing to distinguish the different springback requirements of the cooling channel area and the reinforcing rib area, and further neglecting to consider subsequent welding deformation in bending compensation. In addition, existing welding deformation control technologies are usually independent of the bending process, reducing welding deformation by adjusting welding fixtures, welding sequence, or welding parameters, ignoring that the compensation amount applied during the bending stage changes the residual stress state before welding, thus affecting welding deformation; it also ignores that pre-compensating for non-uniform welding deformation along the bending line during the bending stage can more effectively offset post-weld shape deviations. Summary of the Invention

[0005] In view of the above, the main objective of this invention is to propose a multi-point adaptive bending compensation method and system for new energy battery trays to solve the aforementioned technical problems.

[0006] This invention proposes a multi-point adaptive bending compensation method for new energy battery trays, the method comprising the following steps: Step 1: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line. Step 2: Obtain the subsequent welding process information of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line. Step 3: Couple the springback sensitivity field and the welding deformation tendency field that are continuously distributed along the bending line point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Step 4: By using the non-uniformly distributed bending-welding collaborative compensation field along the bending line, determine the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line, and use the characteristic that the height of each basic unit is independently adjustable to generate a non-uniform compensation surface. Step 5: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic body unit, collect the local reaction force and compression displacement of each basic body unit; use the local reaction force and compression displacement to identify the material deformation stage, and correct the springback sensitivity field and welding pre-compensation amount according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. Step 6: Using the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, apply differentiated holding pressure and holding time to each basic unit, and combine welding pre-compensation to collaboratively control residual stress, so that the bent pallet achieves the target shape accuracy after welding.

[0007] This invention also proposes a multi-point adaptive bending compensation system for new energy battery trays, the system comprising: The rebound sensitivity field generation module is used for: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line. The welding deformation tendency field generation module is used for: Obtain information on the subsequent welding process of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line. The coupling compensation field generation module is used for: The springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, are coupled point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Multi-point mold control module, used for: By using a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line, the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line is determined, and the non-uniform compensation surface is generated by utilizing the characteristic that the height of each basic unit is independently adjustable. The online sensing module is used for: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic unit, the local reaction force and compression displacement of each basic unit are collected; the local reaction force and compression displacement are used to identify the material deformation stage, and the springback sensitivity field and welding pre-compensation amount are corrected according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. The pressure holding and control module is used for: By utilizing the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, differentiated holding pressure and holding time are applied to each basic unit, and residual stress is controlled in conjunction with welding pre-compensation, so that the bent pallet achieves the target shape accuracy after welding.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention addresses the uneven springback and uneven welding deformation caused by local structural features such as cooling channels, reinforcing ribs, areas near welds, and homogeneous areas of battery trays. It constructs a springback sensitivity field and a welding deformation tendency field and performs point-by-point coupling compensation to ensure that the bending angle remains consistent along the bending line direction, significantly improving the flatness of the tray bottom plate and the verticality of the sidewalls.

[0009] 2. This invention couples the pre-compensation amount for welding deformation with the springback sensitivity field, making the pre-compensation amount for welding non-uniformly distributed along the bending line, rather than using a globally uniform value. This coupled calculation simultaneously considers the influence of bending compensation on the residual stress before welding, as well as the influence of welding heat input on the shape after bending, thus achieving collaborative optimization of the shape evolution of the two processes of bending and welding.

[0010] 3. This invention utilizes the highly independent and adjustable differential control capability of each basic unit of the multi-point mold to execute a bending-welding collaborative compensation field that is not uniformly distributed along the bending line. This enables the springback compensation component and the welding pre-compensation component to be executed in a coordinated manner point by point along the bending line, which is something that traditional integral molds cannot achieve. Attached Figure Description

[0011] Figure 1This is a flowchart of a multi-point adaptive bending compensation method for a new energy battery tray proposed in this invention; Figure 2 This is a schematic diagram of the ablation test results of the multi-point adaptive bending compensation system for new energy battery trays proposed in this invention. Figure 3 This is a schematic diagram of the framework of the multi-point adaptive bending compensation system for new energy battery trays proposed in this invention. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0013] These and other aspects of the embodiments of the present invention will become clear from the following description and accompanying drawings. In these descriptions and drawings, some specific embodiments of the present invention are specifically disclosed to illustrate some ways of implementing the principles of the embodiments of the present invention; however, it should be understood that the scope of the embodiments of the present invention is not limited thereto.

[0014] Please see Figure 1 This invention proposes a multi-point adaptive bending compensation method for new energy battery trays, which includes the following steps: Step 1: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line.

[0015] Specifically, in step 1, structural features are scanned along the bending line to generate a springback sensitivity field continuously distributed along the bending line. The specific steps are as follows: The material thickness variation, cooling channel groove position depth, reinforcing rib position height, flange hole position, mounting hole position, local thinning area, and local thickening area within the preset neighborhood on both sides of the bending line are scanned to obtain the structural feature scanning results. Based on the structural feature scanning results, the degree of change of the moment of inertia of the corresponding section relative to the homogeneous section, the degree of change of material continuity, and the local stiffness distribution are determined at each position on the bending line, and the structural feature evaluation results are obtained. Based on the structural feature evaluation results, the structural feature types corresponding to each position on the bending line are determined. The structural feature types include at least a cooling channel weakening zone, a reinforcing rib enhancement zone, and a homogeneous region. The springback sensitivity values ​​at each position on the bending line are determined according to the structural feature types to generate a springback sensitivity field continuously distributed along the bending line. The springback sensitivity value at the location of the cooling channel groove is greater than that of the homogeneous region, and the springback sensitivity value at the location of the reinforcing rib is less than that of the homogeneous region. The springback sensitivity field transitions smoothly at the structural feature changes.

[0016] It should be noted that the following describes the implementation process of the present invention using a specific scenario of bending a 6061 aluminum alloy battery tray. A certain model of new energy battery tray is made of 6061 aluminum alloy sheet with a thickness of 2.0mm and a side wall bending angle of 90°. The tray bottom plate has three longitudinal cooling channels with a depth of 1.2mm and a width of 8mm. The channel areas are distributed along the bending line in the middle and on both sides of the bottom plate. The bottom plate also has two transverse reinforcing ribs with a height of 2.5mm in the middle. After bending, continuous laser filler wire welding is required in the transition area between the tray side wall and the bottom plate. The welds are distributed along the bending line, and the welding sequence is from the middle to both ends.

[0017] Step 2: Obtain the subsequent welding process information of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line.

[0018] Specifically, in step 2, the subsequent welding process information of the battery tray is obtained, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, the welding deformation tendency at each position is evaluated along the bending line direction, generating a welding deformation tendency field continuously distributed along the bending line. The specific steps are as follows: To obtain subsequent welding process information for battery trays, including weld location, welding method, welding heat input, welding sequence, welding fixture constraints, and weld joint type, a welding process information set is obtained. Based on the welding process information set, the tendency of angular deformation, shrinkage deformation and instability deformation to occur at each position after welding is evaluated along the bending line direction, and the evaluation results of welding deformation tendency at each position are obtained. Based on the welding deformation tendency assessment results at each location, locations directly passed by or near the weld, locations with weaker fixture constraints, and locations where the cooling channel cross-section is weakened are identified as locations with a greater welding deformation tendency, while locations with stronger fixture constraints and locations of reinforcing ribs are identified as locations with a smaller welding deformation tendency, thus obtaining the welding deformation tendency distribution results; among them, the area directly affected by the weld is used as the region label of the welding deformation tendency field and corresponds to each location of the bending line. Based on the welding deformation tendency distribution results, the welding deformation tendency at each location is continuously distributed along the bending line to generate a welding deformation tendency field continuously distributed along the bending line. The welding deformation tendency field continuously distributed along the bending line is then made to correspond point by point with the springback sensitivity field continuously distributed along the bending line in the same bending line coordinate system.

[0019] Step 3: Couple the springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line.

[0020] Specifically, in step 3, the springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, are coupled point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. The specific steps are as follows: Based on the springback sensitivity field continuously distributed along the bending line, the springback sensitivity value at each position on the bending line is determined; based on the welding deformation tendency field continuously distributed along the bending line, the welding deformation tendency value at each position on the bending line is determined. Based on the springback sensitivity value and welding deformation tendency value at each position on the bending line, combined with the structural feature type, welding deformation tendency assessment results, preset residual stress influence mapping relationship, preset heat input influence mapping relationship and multi-point mold configuration information, the coupling calculation input parameters at each position are determined. Based on the input parameters of the coupling calculation at each position, a bidirectional coupling coordination calculation is performed on each position on the bending line to obtain the total compensation amount at each position. The total compensation amount includes the component that offsets the bending springback and the component that offsets the welding deformation. The two components are not directly superimposed after independent calculation, but rather influence each other and are coordinated and distributed in the bidirectional coupling coordination calculation. Based on the total compensation amount at each position, a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line is generated.

[0021] Furthermore, based on the coupling calculation input parameters at each location, a bidirectional coupling coordination calculation is performed at each location on the bending line to obtain the total compensation amount at each location. The bidirectional coupling coordination calculation includes: For the weakened area of ​​the cooling channel, under the premise of ensuring that the shape of the part meets the standard after welding, the ratio of springback compensation to welding pre-compensation is adjusted, and the basic body units in the weakened area of ​​the cooling channel are used to disperse and press down to obtain the compensation amount distribution result of the weakened area of ​​the cooling channel. For the stiffener reinforcement zone, the absolute value of the springback compensation component in the total compensation amount of the current zone is made greater than the absolute value of the welding pre-compensation component, so as to obtain the compensation amount distribution result of the stiffener reinforcement zone. The weld location and affected area range of the welding process information are mapped to the bending line coordinate system to determine the direct action area of ​​the weld. For the direct action area of ​​the weld, the absolute value of the welding pre-compensation component in the total compensation amount of the current area is made to be greater than the absolute value of the springback compensation component. A pre-set deformation opposite to the welding deformation direction is applied to the basic body unit near the weld in the multi-point mold to obtain the compensation amount distribution result of the direct action area of ​​the weld. When the same location belongs to at least two of the following areas: the cooling channel weakening zone, the stiffener reinforcement zone, and the weld direct action zone, the compensation amount allocation result for the current location shall be determined according to the principle of prioritizing welding pre-compensation and coordinating springback compensation. For the homogeneous region, based on the coupled calculation input parameters at each location, the springback compensation and welding pre-compensation in the homogeneous region are coupled and coordinated according to a preset weight coefficient to obtain the total compensation amount of the homogeneous region. The preset weight coefficient represents the relative contribution of the springback compensation component and the welding pre-compensation component to the total compensation amount after coupling and coordination. The total compensation amount is not directly obtained by adding the independently obtained springback compensation component and the welding pre-compensation component. The total compensation amount of the homogeneous region is used as the compensation amount allocation result of the homogeneous region. The compensation distribution results of the cooling channel weakening zone, the stiffener reinforcement zone, the weld direct action zone, and the homogeneous zone are integrated along the bending line to obtain the total compensation amount at each position on the bending line.

[0022] It should be noted that the preset residual stress influence mapping relationship can be obtained through finite element simulation or experimental calibration, and is used to characterize the correspondence between the compensation amount applied during the bending stage and the residual stress before welding at that position; the preset heat input influence mapping relationship can be obtained through welding heat source simulation or experimental calibration, and is used to characterize the correspondence between the welding heat input and the shape change after bending at that position.

[0023] Furthermore, the springback compensation ratio and the welding pre-compensation ratio are calculated based on the sum of the absolute values ​​of the springback compensation component and the welding pre-compensation component, and the sum of the two is 1. The ratio only represents the relative contribution weight in the bidirectional coupling coordination calculation, used to determine the coordination direction, and does not represent the total compensation amount obtained by directly adding two independent components. The total compensation amount is not a simple linear superposition of the independently obtained springback compensation component and the welding pre-compensation component. For the reinforcing rib reinforcement area, the springback compensation ratio is greater than the welding pre-compensation ratio. For the weld direct action area, the welding pre-compensation ratio is greater than the springback compensation ratio. For the homogeneous area, based on the coupling calculation input parameters at each location, coupling is performed according to a preset weight coefficient. In the coordinated allocation, the preset weight coefficient represents the relative contribution of the springback compensation component and the welding pre-compensation component to the total compensation amount after coupling and coordination, rather than directly adding the two independently calculated components linearly. For the cooling channel weakening zone, the ratio of the two is adjusted on the premise of ensuring that the shape meets the standard after welding, and multiple basic body units are used to disperse the downward pressure. When the same position belongs to at least two types of regions at the same time, the compensation amount allocation result is determined according to the principle of prioritizing welding pre-compensation and coordinating and correcting springback compensation. Among them, when the direct action zone of the weld overlaps with the cooling channel weakening zone or the reinforcing zone of the stiffener, the proportion of welding pre-compensation is prioritized to be greater than the proportion of springback compensation, and when it overlaps with the cooling channel weakening zone, dispersed downward pressure is also adopted.

[0024] It should be noted that the above-mentioned coupling coordination allocation is different from directly linearly adding the springback compensation component and the welding pre-compensation component after calculating them independently; the preset weight coefficient is used to allocate the relative contribution of the two in the two-way coupling coordination calculation, and the total compensation amount is the result of the coupling calculation.

[0025] Step 4: By using the non-uniformly distributed bending-welding collaborative compensation field along the bending line, determine the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line, and use the characteristic that the height of each basic unit is independently adjustable to generate a non-uniform compensation surface.

[0026] Specifically, in step 4, the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line is determined by the non-uniformly distributed bending-welding collaborative compensation field along the bending line. The non-uniform compensation surface is generated by utilizing the independent adjustable height of each basic unit. The specific steps are as follows: By utilizing the bending-welding collaborative compensation field, the corresponding downward pressure compensation amount is determined for each basic unit, so as to obtain the downward pressure compensation amount of each basic unit; By utilizing the downward pressure compensation amount of each basic unit, and according to the correspondence that the larger the total compensation amount in the bending-welding collaborative compensation field that is non-uniformly distributed along the bending line, the larger the downward pressure amount of the corresponding basic unit, and the smaller the total compensation amount, the smaller the downward pressure amount of the corresponding basic unit, the distribution of downward pressure amount of each basic unit is obtained, and the result of the downward pressure amount distribution is obtained. Based on the distribution of downward pressure, the compensation amount of each basic unit is continuously transitioned along the bending line direction to generate a non-uniform compensation profile, which simultaneously includes components that offset bending springback and components that offset welding deformation.

[0027] Step 5: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic unit, collect the local reaction force and compression displacement of each basic unit; use the local reaction force and compression displacement to identify the material deformation stage, and correct the springback sensitivity field and welding pre-compensation amount according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount.

[0028] Specifically, in step 5, during the bending process, based on the compressive compensation amount and non-uniform compensation surface of each basic unit, the local reaction force and compressive displacement of each basic unit are collected; the local reaction force and compressive displacement are used to identify the material deformation stage, and the springback sensitivity field and welding pre-compensation amount are corrected according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. The specific steps are as follows: Based on the non-uniform compensation surface, during the bending equipment's pressing action, the force sensing element and displacement sensing element integrated on each basic unit are used to collect the local reaction force and pressing displacement at the position of each basic unit according to the preset sampling period, so as to obtain the local reaction force and pressing displacement data of each basic unit. Based on the local reaction force and downward displacement data of each basic element, the deformation stage of the material at each location is identified according to the changing trend of local reaction force with downward displacement, and the material deformation stage identification results at each location are obtained. Based on the material deformation stage identification results at each location, the compensation amount and welding pre-compensation amount at each location are corrected to obtain the corrected compensation amount and welding pre-compensation amount at each location. The local reaction forces of each basic element, the downward displacement data of each basic element, the compensation amount after correction at each position, and the welding pre-compensation amount after correction at each position are fused together to reconstruct the springback sensitivity field and correct the bending-welding collaborative compensation field, thus obtaining the updated bending-welding collaborative compensation field.

[0029] Furthermore, based on the material deformation stage identification results at each location, the compensation amount and welding pre-compensation amount at each location are corrected to obtain the corrected compensation amount and welding pre-compensation amount at each location. Specifically, this includes the following steps: Based on the local reaction force and downward displacement data of each basic unit, combined with the material deformation stage identification results at each location, the bending reaction force value of each region on the bending line is determined to obtain the bending reaction force value of each region. Based on the material deformation stage identification results at each location, the local reaction force growth rate at each location is determined. When the local reaction force growth rate at a certain location is greater than the preset growth rate threshold, the compensation amount at the current location is increased. When the local reaction force growth rate at a certain location is less than or equal to the preset growth rate threshold, the compensation amount at the current location is decreased, and the corrected compensation amount at each location is obtained. The bending reaction force value of each region is compared with the preset reaction force threshold. When the bending reaction force value of a certain region is greater than the preset reaction force threshold, the welding pre-compensation amount of the current region is increased to obtain the first welding pre-compensation amount correction result. When the bending reaction force value of a certain region is less than or equal to the preset reaction force threshold, the welding pre-compensation amount of the current region is decreased to obtain the second welding pre-compensation amount correction result. The first and second welding pre-compensation correction results are integrated according to position to obtain the corrected welding pre-compensation amount for each position.

[0030] Step 6: Using the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, apply differentiated holding pressure and holding time to each basic unit, and combine welding pre-compensation to collaboratively control residual stress, so that the bent pallet achieves the target shape accuracy after welding.

[0031] Specifically, in step 6, the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount are used to apply differentiated holding pressure and holding time to each basic unit, and the residual stress is controlled in conjunction with the welding pre-compensation to ensure that the bent pallet achieves the target shape accuracy after welding. The specific steps are as follows: By using the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, the springback sensitivity value and welding deformation tendency value at each position on the bending line are determined, so as to obtain the springback sensitivity value and welding deformation tendency value at each position. By utilizing the springback sensitivity value and welding deformation tendency value at each location, for locations where the springback sensitivity value is greater than the preset sensitivity threshold, the holding time is extended and the holding pressure is increased; for locations where the springback sensitivity value is less than or equal to the preset sensitivity threshold, the holding time is shortened and the holding pressure is reduced, and the first holding pressure parameter allocation result is obtained. Based on the first pressure holding parameter allocation result, the springback sensitivity value and welding deformation tendency value at each position, the material is kept in a compressive stress state by holding pressure near the welding heat-affected zone to counteract the tensile stress generated during the welding process, and the second pressure holding parameter allocation result is obtained. Based on the second pressure holding parameter allocation result, for positions where the welding deformation tendency value is greater than the preset tendency threshold and the springback sensitivity value is greater than the preset sensitivity threshold, a preset longest pressure holding time and a preset maximum pressure holding pressure are adopted. For positions where the welding deformation tendency value is less than or equal to the preset tendency threshold and the springback sensitivity value is less than or equal to the preset sensitivity threshold, the pressure holding time is shortened and the pressure holding pressure is reduced, and the final pressure holding parameter allocation result of each basic body unit is obtained. Based on the final pressure holding parameter allocation results of each basic unit, pressure holding control instructions are generated. During the pressure holding stage, the pressure holding pressure and pressure holding time of each basic unit are controlled by the pressure holding control instructions. Combined with welding pre-compensation, residual stress is synergistically regulated so that the bent pallet achieves the target shape accuracy after welding.

[0032] It should be noted that, for ease of understanding, the complete implementation process is given below: The 3D model of the tray was read, and structural features were scanned along the sidewall bending line, covering an area of ​​15mm on both sides of the bending line. The positions and depths of three cooling channels, the positions and heights of two reinforcing ribs, and homogeneous areas without special structures were identified. Based on the degree of change of the moment of inertia of each section relative to the homogeneous section, a springback sensitivity field was generated. The springback sensitivity was highest at the cooling channel positions, lowest at the reinforcing rib positions, and intermediate in the homogeneous areas. The springback sensitivity field changed continuously along the bending line, with a smooth transition at the edges of the channels and ribs. Obtain subsequent process information for laser wire filler welding; the weld seam is distributed along the bending line, with concentrated heat input in the middle region and relatively dispersed heat input at both ends; the welding fixture applies strong constraints at both ends of the tray, while the constraints in the middle region are weaker. The cooling channel region, due to its weakened cross-section, is more prone to local instability under welding heat; the reinforcing rib region has high local stiffness and relatively small welding deformation. Based on the above information, a welding deformation tendency field is generated along the bending line, with the middle channel region exhibiting the greatest welding deformation tendency, the homogeneous regions at both ends exhibiting a moderate welding deformation tendency, and the reinforcing rib region exhibiting the least welding deformation tendency. The springback sensitivity field and the welding deformation tendency field are coupled point-by-point in the same coordinate system of the bending line. For each position on the bending line, both springback sensitivity and welding deformation tendency are considered simultaneously. The middle flow channel region has high springback sensitivity and large welding deformation tendency, resulting in the largest total compensation amount after coupling calculation. However, this region is distributed downward by multiple basic body elements to avoid local thinning at the bottom of the flow channel. The homogeneous regions at both ends have moderate springback sensitivity and welding deformation tendency, resulting in moderate total compensation amount. The stiffener region has low springback sensitivity and small welding deformation tendency, resulting in the smallest total compensation amount, with springback compensation being the main factor. In the direct action zone of the weld, the welding pre-compensation component dominates, while the springback compensation component is coordinated and corrected according to the shape requirements after welding. The coupling calculation also considers the influence of bending compensation on the residual stress before welding and the influence of welding heat input on the shape after bending, ultimately generating a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Based on the collaborative compensation field, the downward pressure compensation amount is determined for each basic body unit arranged along the bending line of the multi-point mold. The basic body unit corresponding to the middle flow channel region has the largest downward pressure, but the downward pressure is distributed among multiple units; the units corresponding to the homogeneous regions at both ends have a medium downward pressure; the units corresponding to the reinforcing rib region have the smallest downward pressure; the compensation amount of each basic body unit transitions continuously along the bending line direction, forming a non-uniform compensation profile. This profile simultaneously contains components that offset bending springback and welding deformation. The two components are coupled and coordinated, and are not simply superimposed. After the bending and pressing begins, the force and displacement sensing elements integrated on each basic unit collect local reaction force and pressing displacement according to a preset sampling period (preset to 1ms~5ms, preferably 2ms in this invention). For the basic unit corresponding to the middle flow channel region, if the local reaction force continues to increase rapidly during the plastic stage, it indicates that the flow channel groove weakens the deformation resistance at this location, and the compensation amount of this unit needs to be increased online, and the welding pre-compensation amount at this location should be increased simultaneously, because high residual stress indicates that greater deformation may occur during the welding process. For the basic unit corresponding to the reinforcing rib region, if the local reaction force increases slowly, it indicates that the material flow at this location is sufficient, and the compensation amount of this unit can be appropriately reduced. After fusing the information collected by each unit, the springback sensitivity field is reconstructed and the collaborative compensation field is corrected. After reaching the target bending depth, the process enters the holding pressure stage. For the basic unit corresponding to the middle flow channel region, the holding pressure time is set to 2.5 seconds, and the holding pressure is set to 80% of the peak pressure during the bending stage, allowing the material in this region to undergo sufficient plastic deformation and form a residual stress state conducive to resisting welding deformation. For the basic unit corresponding to the reinforcing rib region, the holding pressure time is set to 1.5 seconds, and the holding pressure is set to 60% of the bending force. For the homogeneous regions at both ends, the values ​​are taken as the midpoint between the two ranges. For the basic unit located near the weld, the holding pressure keeps the material in an appropriate compressive stress state, thereby offsetting the tensile stress generated during welding. After the pressure holding period, the pressure was released, and the distribution of bending angles along the bending line was measured. The bending angle deviation at each position was controlled within ±0.15°. Laser filler wire welding was performed on the bent tray, and the flatness of the sealing surface was checked after welding. The results met the accuracy requirement of 0.3mm. Compared with the scheme without bending-welding coupling compensation, the flatness deviation rate of the sealing surface after welding was reduced, and the shape consistency of the middle flow channel area and the homogeneous areas at both ends was improved.

[0033] Preferably, the above-mentioned preset parameters can be selected or determined in the following ways: the preset neighborhood range on both sides of the bending line is 15mm; the relative contribution weight of the homogeneous region springback compensation is 0.5 and the relative contribution weight of the welding pre-compensation is 0.5 in the preset weight coefficients, which are used for coupling and coordination allocation; the preset growth rate threshold is 1.2 times the average reaction force growth rate in the elastic stage; the preset reaction force threshold is 1.2 times the average bending reaction force in the homogeneous region; the preset sensitivity threshold is the median of the normalized value of the springback sensitivity field; the preset tendency threshold is the median of the normalized value of the welding deformation tendency field; the preset maximum holding time is 2.5s; the preset maximum holding pressure is 80% of the bending force; the multi-point mold has 20 basic units arranged along the bending line, with a unit spacing of 20mm and a height adjustment range of ±5mm.

[0034] To verify the necessity of each technical feature of this invention and its contribution to the final bending-welding shape accuracy, this embodiment uses the complete method as a benchmark and sets up control groups for removing or replacing key features, conducting ablation comparison analysis. The following data are exemplary results based on finite element simulation, used to illustrate the trend of technical effects, and do not constitute a limitation on the scope of protection of this invention; The experimental conditions were as follows: 6061 aluminum alloy sheet, 2.0 mm thick, sidewall bending angle 90°, bottom plate with three longitudinal cooling channels (1.2 mm deep, 8 mm wide) and two transverse reinforcing ribs (2.5 mm high), continuous laser filler wire welding was used after bending, with the welding sequence from the middle to both ends. Points were evenly sampled along the bending line to evaluate the maximum deviation of the bending angle, the flatness of the sealing surface after welding, the flatness deviation rate of the sealing surface, the thinning rate at the bottom of the cooling channels, and the peak residual stress in the weld heat-affected zone.

[0035] Among them, Scheme A is the complete method, which involves point-to-point coupling of the springback sensitivity field and the welding deformation tendency field, non-uniform execution of multi-point molds, online sensing and correction, and differentiated control of holding pressure; Scheme B does not involve a welding deformation tendency field and only performs bending springback compensation; Scheme C does not involve a springback sensitivity field and uses homogeneous springback compensation; Scheme D is a uniform compensation method with a single compensation value along the bending line; Scheme E does not involve multi-point mold differentiation and uses either a whole mold or single-point compensation; Scheme F does not involve online sensing and does not collect local reaction force and downward displacement during the bending process; Scheme G does not involve differentiated holding pressure and uses the same holding pressure and holding time at all positions during the holding pressure stage; the ablation experiment results are as follows: Figure 2 As shown; Please see Figure 2 ,pass Figure 2 The data shows that: Method A achieved a maximum bending angle deviation of ±0.15°, a flatness of 0.25 mm on the sealing surface after welding, a flatness deviation rate of 4%, a thinning rate of 2.8% at the bottom of the flow channel, and a peak residual stress of 185 MPa in the heat-affected zone. All indicators were optimal. This indicates that the point-to-point coupling of the springback sensitivity field and the welding deformation tendency field, the non-uniform execution of the multi-point mold, the online sensing correction, and the differential control of the holding pressure can effectively control the shape accuracy after bending and welding, enabling the bent tray to achieve the target shape accuracy after welding. After removing the welding deformation tendency field in Scheme B, the maximum deviation of the bending angle increased to ±0.22°, the flatness of the sealing surface after welding increased to 0.34 mm, the flatness deviation rate increased to 10%, the thinning rate at the bottom of the flow channel increased to 3.8%, and the peak residual stress in the heat-affected zone increased to 215 MPa. Compared with Scheme A, the flatness of the sealing surface after welding deteriorated significantly, indicating that if only springback compensation is considered in the bending stage without introducing welding deformation pre-compensation, the shape deviation after welding will increase significantly, verifying the necessity of the welding deformation tendency field participating in the coupling compensation. After removing the springback sensitivity field in Scheme C, the maximum deviation of the bending angle is ±0.28°, the flatness of the sealing surface after welding is 0.40mm, the flatness deviation rate is 15%, the thinning rate at the bottom of the flow channel is 5.0%, and the peak residual stress in the heat-affected zone is 235MPa. Since it is impossible to distinguish the different springback characteristics of the cooling flow channel, the reinforcing rib, and the homogeneous region, the compensation amount tends to be averaged, which leads to an increase in the risk of local deviation and thinning at the bottom of the flow channel. This indicates that the springback sensitivity field is the basis for realizing point-by-point coupling compensation along the bending line. Scheme D adopts overall uniform compensation, with a maximum bending angle deviation of ±0.36°, a flatness of 0.49mm on the sealing surface after welding, a flatness deviation rate of 22%, a thinning rate of 6.2% at the bottom of the flow channel, and a residual stress peak of 265MPa in the heat-affected zone. Compared with Scheme A, all indicators are significantly worse, indicating that non-uniform compensation along the bending line is better than the traditional overall uniform compensation method and can better adapt to the unevenness of springback and welding deformation caused by the local structural features of the battery tray. Scheme E lacks multi-point mold differentiation, with a maximum bending angle deviation of ±0.43°, a flatness of 0.56mm on the sealing surface after welding, a flatness deviation rate of 28%, a thinning rate of 7.3% at the bottom of the flow channel, and a peak residual stress of 285MPa in the heat-affected zone, making it the worst among all control groups. This indicates that even if a bending-welding collaborative compensation field is generated, without the ability for each basic unit of the multi-point mold to be independently adjustable, it is impossible to apply the non-uniform compensation amount point by point to the bending line. This further proves that multi-point mold differentiation is an indispensable technical feature of this invention. Scheme F lacks online sensing, with a maximum bending angle deviation of ±0.20°, a post-weld sealing surface flatness of 0.30mm, a flatness deviation rate of 6%, a flow channel bottom thinning rate of 3.2%, and a peak residual stress in the heat-affected zone of 195MPa. Scheme G lacks pressure-holding differentiation, with a maximum bending angle deviation of ±0.21°, a post-weld sealing surface flatness of 0.32mm, a flatness deviation rate of 8%, a flow channel bottom thinning rate of 3.4%, and a peak residual stress in the heat-affected zone of 205MPa. Both schemes outperform schemes B, C, D, and E, but are inferior to method A. This indicates that while online sensing and pressure-holding differentiation are not necessary conditions for achieving non-uniform coupling compensation, they can further modify the collaborative compensation field and improve the residual stress state, thereby enhancing the final shape accuracy and welding reliability. The above ablation experiments show that the point-to-point coupling of the springback sensitivity field and the welding deformation tendency field, and the non-uniform execution of the multi-point mold are the core technical features of this invention, which contribute the most to the final bending-welding shape accuracy. Online sensing and pressure holding differential control are preferred features, which can further optimize the bending-welding collaborative compensation effect on this basis.

[0036] Please see Figure 3 This invention also provides a multi-point adaptive bending compensation system for new energy battery trays, the system comprising: The rebound sensitivity field generation module is used for: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line. The welding deformation tendency field generation module is used for: Obtain information on the subsequent welding process of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line. The coupling compensation field generation module is used for: The springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, are coupled point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Multi-point mold control module, used for: By using a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line, the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line is determined, and the non-uniform compensation surface is generated by utilizing the characteristic that the height of each basic unit is independently adjustable. The online sensing module is used for: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic unit, the local reaction force and compression displacement of each basic unit are collected; the local reaction force and compression displacement are used to identify the material deformation stage, and the springback sensitivity field and welding pre-compensation amount are corrected according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. The pressure holding and control module is used for: By utilizing the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, differentiated holding pressure and holding time are applied to each basic unit, and residual stress is controlled in conjunction with welding pre-compensation, so that the bent pallet achieves the target shape accuracy after welding.

[0037] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in 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.

[0038] In the description of this specification, 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 the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A multi-point adaptive bending compensation method for new energy battery trays, characterized in that, The method includes the following steps: Step 1: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line. Step 2: Obtain the subsequent welding process information of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line. Step 3: Couple the springback sensitivity field and the welding deformation tendency field that are continuously distributed along the bending line point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Step 4: By using the non-uniformly distributed bending-welding collaborative compensation field along the bending line, determine the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line, and use the characteristic that the height of each basic unit is independently adjustable to generate a non-uniform compensation surface. Step 5: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic body unit, collect the local reaction force and compression displacement of each basic body unit; use the local reaction force and compression displacement to identify the material deformation stage, and correct the springback sensitivity field and welding pre-compensation amount according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. Step 6: Using the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, apply differentiated holding pressure and holding time to each basic unit, and combine welding pre-compensation to collaboratively control residual stress, so that the bent pallet achieves the target shape accuracy after welding.

2. The multi-point adaptive bending compensation method for new energy battery trays according to claim 1, characterized in that, In step 1, structural features are scanned along the bending line to generate a springback sensitivity field continuously distributed along the bending line. The specific steps are as follows: The material thickness variation, cooling channel groove position depth, reinforcing rib position height, flange hole position, mounting hole position, local thinning area, and local thickening area within the preset neighborhood on both sides of the bending line are scanned to obtain the structural feature scanning results. Based on the structural feature scanning results, the degree of change of the moment of inertia of the corresponding section relative to the homogeneous section, the degree of change of material continuity, and the local stiffness distribution are determined at each position on the bending line, and the structural feature evaluation results are obtained. Based on the structural feature evaluation results, the structural feature type corresponding to each position on the bending line is determined, and the springback sensitivity value at each position on the bending line is determined according to the structural feature type, so as to generate a springback sensitivity field continuously distributed along the bending line.

3. The multi-point adaptive bending compensation method for new energy battery trays according to claim 2, characterized in that, In step 2, information on the subsequent welding process of the battery tray is obtained, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, the welding deformation tendency at each position is evaluated along the bending line direction, generating a welding deformation tendency field continuously distributed along the bending line. The specific steps are as follows: To obtain subsequent welding process information for battery trays, including weld location, welding method, welding heat input, welding sequence, welding fixture constraints, and weld joint type, a welding process information set is obtained. Based on the welding process information set, the tendency of angular deformation, shrinkage deformation and instability deformation to occur at each position after welding is evaluated along the bending line direction, and the evaluation results of welding deformation tendency at each position are obtained. Based on the welding deformation tendency assessment results at each location, the locations where the weld directly passes through or is close to the location, the location where the fixture is less constrained, and the location where the cooling channel section is weakened are identified as locations with a greater tendency to weld deformation, while the locations where the fixture is more constrained and the location of the reinforcing rib are identified as locations with a less tendency to weld deformation, so as to obtain the welding deformation tendency distribution results. Based on the welding deformation tendency distribution results, the welding deformation tendency at each location is continuously distributed along the bending line to generate a welding deformation tendency field continuously distributed along the bending line. The welding deformation tendency field continuously distributed along the bending line is then made to correspond point by point with the springback sensitivity field continuously distributed along the bending line in the same bending line coordinate system.

4. The multi-point adaptive bending compensation method for new energy battery trays according to claim 3, characterized in that, In step 3, the springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, are coupled point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. The specific steps are as follows: Based on the springback sensitivity field continuously distributed along the bending line, the springback sensitivity value at each position on the bending line is determined; based on the welding deformation tendency field continuously distributed along the bending line, the welding deformation tendency value at each position on the bending line is determined. Based on the springback sensitivity value and welding deformation tendency value at each position on the bending line, combined with the structural feature type, welding deformation tendency assessment results, preset residual stress influence mapping relationship, preset heat input influence mapping relationship and multi-point mold configuration information, the coupling calculation input parameters at each position are determined. Based on the input parameters of the coupling calculation at each position, a bidirectional coupling coordination calculation is performed at each position on the bending line to obtain the total compensation amount at each position; based on the total compensation amount at each position, a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line is generated.

5. The multi-point adaptive bending compensation method for new energy battery trays according to claim 4, characterized in that, Based on the input parameters of the coupling calculation at each location, a two-way coupling coordination calculation is performed at each location on the bending line to obtain the total compensation amount at each location. The two-way coupling coordination calculation includes: For the weakened area of ​​the cooling channel, under the premise of ensuring that the shape of the part meets the standard after welding, the ratio of springback compensation to welding pre-compensation is adjusted, and the basic body units in the weakened area of ​​the cooling channel are used to disperse and press down to obtain the compensation amount distribution result of the weakened area of ​​the cooling channel. For the stiffener reinforcement zone, the absolute value of the springback compensation component in the total compensation amount of the current zone is made greater than the absolute value of the welding pre-compensation component, so as to obtain the compensation amount distribution result of the stiffener reinforcement zone. The weld location and affected area range of the welding process information are mapped to the bending line coordinate system to determine the direct action area of ​​the weld. For the direct action area of ​​the weld, the absolute value of the welding pre-compensation component in the total compensation amount of the current area is made to be greater than the absolute value of the springback compensation component. A pre-set deformation opposite to the welding deformation direction is applied to the basic body unit near the weld in the multi-point mold to obtain the compensation amount distribution result of the direct action area of ​​the weld. When the same location belongs to at least two of the following areas: the cooling channel weakening zone, the stiffener reinforcement zone, and the weld direct action zone, the compensation amount allocation result for the current location shall be determined according to the principle of prioritizing welding pre-compensation and coordinating springback compensation. For the homogeneous region, based on the coupled calculation input parameters at each location, the springback compensation and welding pre-compensation of the homogeneous region are coupled and coordinated according to the preset weight coefficients to obtain the total compensation amount of the homogeneous region. The preset weight coefficients are used to characterize the relative contributions of the springback compensation component and the welding pre-compensation component in the coupled and coordinated allocation. The total compensation amount of the homogeneous region is used as the compensation amount allocation result of the homogeneous region. The compensation distribution results of the cooling channel weakening zone, the stiffener reinforcement zone, the weld direct action zone, and the homogeneous zone are integrated along the bending line to obtain the total compensation amount at each position on the bending line.

6. The multi-point adaptive bending compensation method for new energy battery trays according to claim 5, characterized in that, In step 4, the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line is determined by the bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. The non-uniform compensation profile is generated by utilizing the independent adjustable height of each basic unit. The specific steps are as follows: By utilizing the bending-welding collaborative compensation field, the corresponding downward pressure compensation amount is determined for each basic unit, so as to obtain the downward pressure compensation amount of each basic unit; By utilizing the downward pressure compensation amount of each basic unit, and according to the correspondence that the larger the total compensation amount in the bending-welding collaborative compensation field that is non-uniformly distributed along the bending line, the larger the downward pressure amount of the corresponding basic unit, and the smaller the total compensation amount, the smaller the downward pressure amount of the corresponding basic unit, the distribution of downward pressure amount of each basic unit is obtained, and the result of the downward pressure amount distribution is obtained. Based on the distribution of downward pressure, the compensation amount of each basic unit is continuously transitioned along the bending line direction to generate a non-uniform compensation profile.

7. The multi-point adaptive bending compensation method for new energy battery trays according to claim 6, characterized in that, In step 5, during the bending process, based on the compressive compensation amount and non-uniform compensation surface of each basic unit, the local reaction force and compressive displacement of each basic unit are collected; the local reaction force and compressive displacement are used to identify the material deformation stage, and the springback sensitivity field and welding pre-compensation amount are corrected according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. The specific steps are as follows: Based on the non-uniform compensation surface, during the bending equipment's pressing action, the force sensing element and displacement sensing element integrated on each basic unit are used to collect the local reaction force and pressing displacement at the position of each basic unit according to the preset sampling period, so as to obtain the local reaction force and pressing displacement data of each basic unit. Based on the local reaction force and downward displacement data of each basic element, the deformation stage of the material at each location is identified according to the changing trend of local reaction force with downward displacement, and the material deformation stage identification results at each location are obtained. Based on the material deformation stage identification results at each location, the compensation amount and welding pre-compensation amount at each location are corrected to obtain the corrected compensation amount and welding pre-compensation amount at each location. The local reaction forces of each basic element, the downward displacement data of each basic element, the compensation amount after correction at each position, and the welding pre-compensation amount after correction at each position are fused together to reconstruct the springback sensitivity field and correct the bending-welding collaborative compensation field, thus obtaining the updated bending-welding collaborative compensation field.

8. The multi-point adaptive bending compensation method for new energy battery trays according to claim 7, characterized in that, Based on the material deformation stage identification results at each location, the compensation amount and welding pre-compensation amount at each location are corrected to obtain the corrected compensation amount and welding pre-compensation amount at each location. The specific steps include the following: Based on the local reaction force and downward displacement data of each basic unit, combined with the material deformation stage identification results at each location, the bending reaction force value of each region on the bending line is determined to obtain the bending reaction force value of each region. Based on the material deformation stage identification results at each location, the local reaction force growth rate at each location is determined. When the local reaction force growth rate at a certain location is greater than the preset growth rate threshold, the compensation amount at the current location is increased. When the local reaction force growth rate at a certain location is less than or equal to the preset growth rate threshold, the compensation amount at the current location is decreased, and the corrected compensation amount at each location is obtained. The bending reaction force value of each region is compared with the preset reaction force threshold. When the bending reaction force value of a certain region is greater than the preset reaction force threshold, the welding pre-compensation amount of the current region is increased to obtain the first welding pre-compensation amount correction result. When the bending reaction force value of a certain region is less than or equal to the preset reaction force threshold, the welding pre-compensation amount of the current region is decreased to obtain the second welding pre-compensation amount correction result. The first and second welding pre-compensation correction results are integrated according to position to obtain the corrected welding pre-compensation amount for each position.

9. The multi-point adaptive bending compensation method for new energy battery trays according to claim 8, characterized in that, In step 6, the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount are used to apply differentiated holding pressure and holding time to each basic unit. Combined with welding pre-compensation, residual stress is synergistically controlled to ensure that the bent pallet achieves the target shape accuracy after welding. The specific steps are as follows: By using the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, the springback sensitivity value and welding deformation tendency value at each position on the bending line are determined, so as to obtain the springback sensitivity value and welding deformation tendency value at each position. By utilizing the springback sensitivity value and welding deformation tendency value at each location, for locations where the springback sensitivity value is greater than the preset sensitivity threshold, the holding time is extended and the holding pressure is increased; for locations where the springback sensitivity value is less than or equal to the preset sensitivity threshold, the holding time is shortened and the holding pressure is reduced, and the first holding pressure parameter allocation result is obtained. Based on the first pressure holding parameter allocation result, the springback sensitivity value and welding deformation tendency value at each position, the material is kept in a compressive stress state by holding pressure near the welding heat-affected zone to counteract the tensile stress generated during the welding process, and the second pressure holding parameter allocation result is obtained. Based on the second pressure holding parameter allocation result, for positions where the welding deformation tendency value is greater than the preset tendency threshold and the springback sensitivity value is greater than the preset sensitivity threshold, a preset longest pressure holding time and a preset maximum pressure holding pressure are adopted. For positions where the welding deformation tendency value is less than or equal to the preset tendency threshold and the springback sensitivity value is less than or equal to the preset sensitivity threshold, the pressure holding time is shortened and the pressure holding pressure is reduced, and the final pressure holding parameter allocation result of each basic body unit is obtained. Based on the final pressure holding parameter allocation results of each basic unit, pressure holding control instructions are generated. During the pressure holding stage, the pressure holding pressure and pressure holding time of each basic unit are controlled by the pressure holding control instructions. Combined with welding pre-compensation, residual stress is synergistically regulated so that the bent pallet achieves the target shape accuracy after welding.

10. A multi-point adaptive bending compensation system for new energy battery trays, characterized in that, The system applies the multi-point adaptive bending compensation method for new energy battery trays according to any one of claims 1 to 9, and the system includes: The rebound sensitivity field generation module is used for: Read the 3D model data of the battery tray and scan the structural features along the bending line to be bent in order to generate a spring sensitivity field that is continuously distributed along the bending line. The welding deformation tendency field generation module is used for: Obtain information on the subsequent welding process of the battery tray, and based on the coordinate system of the bending line where the springback sensitivity field is continuously distributed along the bending line, evaluate the welding deformation tendency at each position along the bending line direction, and generate a welding deformation tendency field continuously distributed along the bending line. The coupling compensation field generation module is used for: The springback sensitivity field and the welding deformation tendency field, which are continuously distributed along the bending line, are coupled point by point in the same coordinate system of the bending line to generate a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line. Multi-point mold control module, used for: By using a bending-welding collaborative compensation field that is non-uniformly distributed along the bending line, the downward pressure compensation amount of each basic unit of the multi-point mold arranged along the bending line is determined, and the non-uniform compensation surface is generated by utilizing the characteristic that the height of each basic unit is independently adjustable. The online sensing module is used for: During the bending process, based on the compression compensation amount and non-uniform compensation surface of each basic unit, the local reaction force and compression displacement of each basic unit are collected; the local reaction force and compression displacement are used to identify the material deformation stage, and the springback sensitivity field and welding pre-compensation amount are corrected according to the material deformation stage to obtain the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount. The pressure holding and control module is used for: By utilizing the updated bending-welding collaborative compensation field and the corrected welding pre-compensation amount, differentiated holding pressure and holding time are applied to each basic unit, and residual stress is controlled in conjunction with welding pre-compensation, so that the bent pallet achieves the target shape accuracy after welding.

Images