A new energy automobile high-strength steel plate profile edge part anti-up measurement method and system

Abstract

The application provides a new energy automobile high-strength steel plate profile edge anti-up measurement method and system, relates to the stamping steel plate profile edge detection technical field, and includes the following steps: according to the steel plate type of the steel plate to be detected, the profile edge area of the steel plate to be detected is acquired;Real-time monitoring of the stamping process signal of the steel plate to be detected, according to the stamping process signal, when determining the trigger anti-up measurement of the profile edge area, the profile edge area of the steel plate carried on the lower die is scanned, the target three-dimensional point cloud data of the profile edge area is acquired, the bearing plane of the lower die is taken as the reference plane, the target three-dimensional point cloud data is projected to the reference plane, and the first normal distance of each target point to the reference plane is calculated;The maximum first normal distance is taken as the measured anti-up height. The method can directly capture the instantaneous anti-up state of the steel plate after unloading in the mold bearing environment, realize real-time accurate measurement of the stamping process, and effectively control the quality risk of the structural part of the high-strength steel plate.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of stamping steel plate profile edge detection, and particularly relates to a new energy automobile high-strength steel plate profile edge anti-upwarping measurement method and system. BACKGROUND

[0002] In the field of stamping of new energy automobile high-strength steel plates, real-time measurement of edge anti-upwarping defects is a key to guarantee the quality of vehicle body structure parts, but there is no relatively accurate method for measuring the anti-upwarping height after stamping. An anti-upwarping evaluation method disclosed in an invention patent with the application number 202210397146.9 and the name of a strip steel plate profile anti-upwarping evaluation method has been tried. Although the method can serve the optimization of rolling processes, the rolling measurement of the method is for continuous and uniform deformation in the rolling scene, and depends on the thickness data of the plate profile gauge in the rolling production line. Therefore, the method has poor adaptability when used in the die bearing environment of the stamping process. SUMMARY

[0003] In view of the above defects or deficiencies in the prior art, the application aims to provide a new energy automobile high-strength steel plate profile edge anti-upwarping measurement method and system to realize the anti-upwarping measurement of the steel plate profile edge after the stamping process.

[0004] In a first aspect, the application provides a new energy automobile high-strength steel plate profile edge anti-upwarping measurement method, which comprises the following steps:

[0005] According to the type of the steel plate to be detected, the profile edge region of the steel plate to be detected is obtained;

[0006] The stamping process signal of the steel plate to be detected is monitored in real time, and whether the anti-upwarping measurement of the profile edge region is triggered is judged according to the stamping process signal;

[0007] If yes, the profile edge region of the steel plate carried on the lower die is scanned, target three-dimensional point cloud data of the profile edge region is obtained, the target three-dimensional point cloud data comprises a plurality of target points on the profile edge region and a first spatial coordinate of each target point;

[0008] The bearing plane of the lower die is taken as a reference plane, the target three-dimensional point cloud data is projected to the reference plane, and the first normal distance of each target point to the reference plane is calculated;

[0009] The maximum first normal distance is taken as the measured anti-upwarping height.

[0010] According to the technical scheme provided by the application, the stamping process signal comprises a slider displacement encoder signal of a stamping machine;

[0011] The method comprises the following steps of:

[0012] Based on the slider displacement encoder signal, it is judged whether the upper die has risen to a preset die opening safety height.

[0013] If yes, it is determined that the reverse kick measurement of the edge part area is triggered.

[0014] According to the technical scheme provided in the present application, the edge part area is scanned by a non-contact scanning device, which is a line laser scanner installed on a movable device that can move to a measurement position. An inertial measurement unit is provided on the movable device to measure the six-degree-of-freedom pose change data of the line laser scanner in real time during the entire scanning process.

[0015] After taking the maximum first normal distance as the measured reverse kick height, the following steps are further included:

[0016] The six-degree-of-freedom pose change data is retrieved to generate a pose jitter data set, which includes a plurality of time stamp corresponding translation vectors.

[0017] The magnitude of each translation vector is calculated to obtain the corresponding pose jitter amplitude.

[0018] If all the pose jitter amplitudes are less than a preset jitter threshold, the measured reverse kick height is output.

[0019] According to the technical scheme provided in the present application, after obtaining the corresponding pose jitter amplitude, the following steps are further included:

[0020] If at least one of the pose jitter amplitudes is greater than or equal to the preset jitter threshold, the translation vector corresponding to the pose jitter amplitude greater than or equal to the preset jitter threshold and the corresponding time stamp are extracted to form a pose jitter vector sequence.

[0021] Based on the pose jitter vector sequence, the target three-dimensional point cloud data is spatio-temporally synchronized and corrected to obtain corrected point cloud data.

[0022] The corrected point cloud data is projected onto the reference plane to calculate the second normal distance of each point of the edge part to the reference plane.

[0023] The maximum second normal distance is taken as the corrected reverse kick height and output.

[0024] According to the technical scheme provided in the present application, after forming the pose jitter vector sequence, the following steps are further included:

[0025] determine whether each of the translation vectors in the pose jitter vector sequence can be decomposed into a height jitter component perpendicular to the reference plane;

[0026] correct the target three-dimensional point cloud data in space-time synchronization based on the pose jitter vector sequence to obtain modified point cloud data, including the following steps:

[0027] If at least one of the translation vectors can be decomposed into the height jitter component, correct the target three-dimensional point cloud data in space-time synchronization based on the pose jitter vector sequence to obtain modified point cloud data.

[0028] According to the technical scheme provided in the present application, after determining whether each of the translation vectors can be decomposed into a height jitter component perpendicular to the reference plane, the following steps are further included:

[0029] If all of the translation vectors cannot be decomposed into the height jitter component, output the measured anti-heave height.

[0030] According to the technical scheme provided in the present application, if at least one of the translation vectors can be decomposed into the height jitter component, correct the target three-dimensional point cloud data in space-time synchronization based on the pose jitter vector sequence to obtain modified point cloud data, including the following steps:

[0031] Decompose the translation vectors in the pose jitter vector sequence that can be decomposed into the height jitter component to obtain corresponding height jitter components to form a correction vector sequence, the correction vector sequence including a plurality of height jitter components and time stamps corresponding to each height jitter component;

[0032] For each target point in the target three-dimensional point cloud data, extract the collection time corresponding to each target point;

[0033] Take the target point corresponding to the collection time matching the time stamp in the correction vector sequence as a point to be corrected, and the collection time corresponding to the point to be corrected is a target time;

[0034] Correct the point to be corrected with the height jitter component corresponding to the target time in the correction vector sequence to obtain modified point cloud data.

[0035] According to the technical scheme provided in the present application, the bearing plane of the lower mold is taken as the reference plane, including the following steps:

[0036] Retrieve the pre-set calibration plane equation of the bearing plane, which is obtained by calibration at room temperature;

[0037] If the continuous working time length of the lower mold is less than a first preset time length, and the deviation amount of the real-time temperature of each temperature measuring point on the bearing plane from the normal temperature is less than a first preset threshold, the plane corresponding to the calibration plane equation is taken as the reference plane.

[0038] According to the technical scheme provided in the application, after the calibration plane equation of the bearing plane is called, the following steps are further included:

[0039] If the continuous working time length of the lower mold is greater than or equal to the first preset time length, or the deviation amount of the real-time temperature of each temperature measuring point on the bearing plane from the normal temperature is greater than or equal to the first preset threshold, a temperature abnormal point is obtained.

[0040] According to the real-time temperature of the temperature abnormal point, an equivalent temperature rise is obtained.

[0041] According to the equivalent temperature rise, the calibration plane equation is corrected to obtain a corrected plane equation.

[0042] The plane corresponding to the corrected plane equation is taken as the reference plane.

[0043] In a second aspect, the application provides a new energy automobile high-strength steel plate edge portion anti-lifting measurement system for implementing the new energy automobile high-strength steel plate edge portion anti-lifting measurement method as described above, comprising:

[0044] A calling module is configured to obtain the edge portion region of the steel plate to be detected according to the steel plate type of the steel plate to be detected.

[0045] A monitoring module is configured to monitor the stamping process signal of the steel plate to be detected in real time, and determine whether to trigger the anti-lifting measurement of the edge portion region according to the stamping process signal.

[0046] A measurement module is configured to, if so, scan the edge portion region of the steel plate carried on the lower mold, obtain target three-dimensional point cloud data of the edge portion region, and the target three-dimensional point cloud data includes a plurality of target points on the edge portion region and a first spatial coordinate of each target point.

[0047] The measurement module is further configured to take the bearing plane of the lower mold as a reference plane, project the target three-dimensional point cloud data to the reference plane, calculate the first normal distance of each target point to the reference plane, and take the maximum first normal distance as the measured anti-lifting height.

[0048] Compared with the prior art, the beneficial effects of the present application are that the present application realizes real-time accurate measurement of the stamping process: the measurement opportunity is dynamically triggered in real time by monitoring the stamping process signal, solving the problem that the traditional rolling scene method cannot adapt to the non-continuous and transient deformation characteristics of the stamping process, and the instantaneous reverse buckling state after the unloading of the steel plate can be directly captured in the mold bearing environment. Breakthrough the limitations of the rolling scene method: replace the thickness detection of the rolling plate profiler with three-dimensional point cloud scanning, and get rid of the dependence on the assumption of continuous and uniform deformation of the rolling production line, which can accurately capture the local non-uniform deformation characteristics of the profile edge part after stamping, and significantly improve the reliability of the reverse buckling height data. Adapt the reference to the actual working condition of the die: take the die bearing plane as the reference plane to calculate the normal distance, which directly reflects the actual fitting state of the steel plate on the die, and take the maximum normal distance of the point cloud data as the reverse buckling height to establish a quantifiable defect evaluation index, which provides high-precision data support for process adjustment (such as die compensation and blank holder force optimization), and effectively controls the quality risk of structural parts of high-strength steel plates. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 A step flow chart of the reverse buckling measurement method of the profile edge part of the high-strength steel plate of the new energy vehicle provided by the present application is provided.

[0050] Figure 2 A structural schematic diagram of the reverse buckling measurement system of the profile edge part of the high-strength steel plate of the new energy vehicle provided by the present application is provided. DETAILED DESCRIPTION

[0051] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the related application, and not to limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0052] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and examples.

[0053] Example 1

[0054] As mentioned in the background, in view of the problems in the prior art, the present application provides a reverse buckling measurement method for the profile edge part of a high-strength steel plate of a new energy vehicle, as shown in Figure 1 , including the following steps:

[0055] S1, according to the steel plate type of the steel plate to be detected, obtaining the profile edge part region of the steel plate to be detected;

[0056] Specifically, the steel plate type refers to a high-strength steel plate brand (such as DP980, MS1500, etc.) for a new energy vehicle body and a corresponding part specification (a door anti-collision beam, a B-column reinforcing plate, etc.). A steel plate type database is preset in the system, a definition rule of a profile edge part area corresponding to different steel plate types is stored, a steel plate type is input by scanning a steel plate two-dimensional code or a MES system, and a corresponding area coordinate range of the profile edge part is automatically called according to an edge deformation sensitive area experience value of a vehicle body structure part (such as a laser tailor-welded plate: 50mm range on both sides of a weld; a door sill beam part: 30mm at both ends in the length direction + an outer edge in the width direction).

[0057] S2, monitoring a stamping process signal of the steel plate to be detected in real time, and judging whether to trigger the reverse buckling measurement of the profile edge part area according to the stamping process signal;

[0058] Further, the stamping process signal includes a slider displacement encoder signal of a punch press;

[0059] The judgment whether to trigger the reverse buckling measurement of the profile edge part area according to the stamping process signal includes the following steps:

[0060] Judging whether the upper die has risen to a preset die opening safety height based on the slider displacement encoder signal;

[0061] If yes, it is determined that the reverse buckling measurement of the profile edge part area is triggered.

[0062] Specifically, the slider displacement encoder is an absolute photoelectric encoder installed at the end of the crankshaft of the punch press, and the crankshaft angle and the slider displacement have a corresponding relationship. Therefore, the rising height of the upper die can be obtained according to the slider displacement encoder signal, the preset safety height can be selected as the sum of the part height, the safety distance of the scanner and the margin (usually ≥100mm), and when the rising height of the upper die is greater than or equal to the preset die opening safety height, it indicates that the upper die is completely separated from the steel plate, the stamping is completed, and the scanner can be prevented from colliding with the die.

[0063] S3, if yes, scanning the profile edge part area of the steel plate carried on the lower die to obtain target three-dimensional point cloud data of the profile edge part area, the target three-dimensional point cloud data including a plurality of target points on the profile edge part area and a first spatial coordinate of each target point;

[0064] S4, taking the carrying plane of the lower die as a reference plane, projecting the target three-dimensional point cloud data to the reference plane, and calculating a first normal distance of each target point to the reference plane;

[0065] Further, the taking the carrying plane of the lower die as the reference plane includes the following steps:

[0066] The calibration plane equation preset for the bearing plane is called, and the calibration plane equation is obtained by calibration at normal temperature;

[0067] If the continuous working time of the lower mold is less than the first preset time, and the deviation of the real-time temperature of the plurality of temperature measuring points on the bearing plane from the normal temperature is less than the first preset threshold, the plane corresponding to the calibration plane equation is taken as the reference plane.

[0068] Specifically, in the high-temperature working environment of the stamping mold, the bearing plane of the lower mold will be deformed due to thermal expansion (for example, the thermal expansion coefficient of the mold steel is about 12×10 -6 / ℃, and a temperature rise of 50℃ can cause a flatness deviation of more than 0.1mm). If the plane equation calibrated at normal temperature is directly used as the reference, systematic measurement errors will be introduced, which will significantly affect the detection accuracy of new energy vehicle high-strength steel plates (which have strict tolerance for anti-warping). Therefore, the present embodiment first calibrates the preset plane equation: the absolute flatness of the mold bearing surface is calibrated at normal temperature (20±2℃) by a laser interferometer or a three-coordinate machine, and a high-precision reference is established. Double-condition verification: the working time limit corresponds to the first preset time: the initial stage of continuous mold working (the first preset time is 12h) corresponds to the state of unsaturated heat accumulation, and there is no deformation, and the real-time temperature of the plurality of temperature measuring points under the edge part of the bearing plane is monitored to ensure that the local temperature rise ΔT is less than the first preset threshold (which can be selected as) 10℃ (corresponding to a flatness deviation of less than 0.06mm).

[0069] The present embodiment excludes the problem of reference failure caused by thermal deformation of the lower mold bearing plane through time-temperature double threshold screening, and ensures the effectiveness of the reference plane equation.

[0070] Specifically, the calibration plane equation is ax+by+cz+d=0, and the normal distance calculation formula is , wherein (x i , y i , z i ) is the first spatial coordinate of the target point i, D i is the first normal distance from the target point i to the reference plane. All point cloud normal distances are traversed, and the maximum value H max =max(D1,D2,...,D n ) is taken.

[0071] S5, taking the maximum first normal distance as the measured anti-warping height.

[0072] Specifically, the high-strength steel sheet is deformed in a "fish mouth" shape, and the maximum distance corresponds to the most serious defect point. The measurement is performed during the elastic rebound stabilization period (within 1.5 seconds after stamping) to avoid the secondary deformation error caused by the traditional offline measurement due to transportation, accurately capture the transient deformation, take the actual bearing surface as the reference, eliminate the system error caused by the mold thermal expansion, and improve the reference reliability.

[0073] In a preferred embodiment, the profiled portion region is scanned by a non-contact scanning device, which is a line laser scanner mounted on a movable device that can be moved to a measurement position, and the movable device is provided with an inertial measurement unit for measuring the six-degree-of-freedom pose change data of the line laser scanner in real time during the entire scanning process.

[0074] Specifically, the device is composed of: a line laser scanner that selects a blue laser source with a precision of 0.05 mm (such as Keyence LJ-X8000), a wavelength of 405 nm (anti-environmental light interference), an AGV chassis for the movable device, and an integrated linear guide; an inertial measurement unit (IMU) that uses a 6-axis MEMS sensor (3-axis accelerometer + 3-axis gyroscope) to record the pose change of the line laser scanner in real time during the measurement process, with a sampling frequency of ≥1 kHz, the IMU data and the point cloud collection timestamp of the line laser scanner are strictly aligned, the line laser scanner is installed on the top of the AGV chassis through a universal cloud platform, the initial pose is at an angle of 45° with the lower mold plane, the inertial measurement unit is rigidly fixed on the scanner base, and the coordinate system is aligned with the line laser scanner coordinate system.

[0075] After taking the maximum first normal distance as the measured kick-up height, the following steps are further included:

[0076] The six-degree-of-freedom pose change data is retrieved to generate a pose jitter data set, and the pose jitter data set includes a plurality of time stamp corresponding translation vectors;

[0077] Specifically, the six-degree-of-freedom pose change data includes a six-degree-of-freedom pose data packet corresponding to each time stamp (t), including a translation vector (Δx, Δy, Δz): XYZ three-axis displacement change (unit: mm) and a rotation vector (Δα, Δβ, Δγ): angular displacement change around XYZ three-axis (unit: degree).

[0078] The magnitude of each translation vector is calculated to obtain the corresponding pose jitter amplitude;

[0079] Specifically, the magnitude of each translation vector corresponding to each time stamp is calculated to obtain the pose jitter amplitude.

[0080] If all the pose jitter amplitudes are less than a preset jitter threshold, the measured kick-up height is output. ​

[0081] Specifically, when the punch completes the stamping (the upper die rises to a safe height), the AGV moves to the steel plate above along the preset track. The AGV performs scanning in three steps: first, quickly moves to the scanning starting point, second, completely stops and locks the position (the scanner turns on the laser), and third, collects the 0.3-second steel plate edge part and then moves to the next scanning point. The shaking monitoring stage: the IMU collects 1000 displacement data per second. The system automatically distinguishes two states: moving state: the AGV is traveling (a certain shaking is allowed, which is considered normal), and scanning state: the AGV is completely stationary (absolute stability is required at this time); the shaking judgment stage: only the IMU data in the scanning state is analyzed to form a pose shaking data set, and the shaking amplitude of the device at each stationary time is calculated as the modulus of the translation vector. If all shaking amplitudes in the scanning state are less than 0.05 mm, it is determined that the measured reverse kick height is valid.

[0082] Further, after obtaining the corresponding pose shaking amplitude, the following steps are further included:

[0083] If at least one of the pose shaking amplitudes is greater than or equal to the preset shaking threshold, the translation vector corresponding to the pose shaking amplitude greater than or equal to the preset shaking threshold and the corresponding timestamp are extracted to form a pose shaking vector sequence;

[0084] Specifically, if it is found that the device shakes ≥0.05 mm during scanning (such as a forklift passing by causing vibration), the system automatically records the abnormal period (such as 13:05:25.300-13:05:25.500) and marks the multiple scanning points collected during this period.

[0085] Based on the pose shaking vector sequence, the target three-dimensional point cloud data is spatiotemporally synchronized and corrected to obtain corrected point cloud data;

[0086] The corrected point cloud data is projected onto the reference plane, and a second normal distance of each point of the edge part to the reference plane is calculated;

[0087] The maximum second normal distance is taken as the corrected reverse kick height and output.

[0088] Specifically, according to the vibration direction recorded by the IMU (such as the device lifting 0.1 mm upward), the scanning points in this period are adjusted in the opposite direction (all point coordinates are lowered by 0.1 mm), the reverse kick height of the edge part is calculated again using the corrected data (the same method as calculating the first normal distance), and the corrected reverse kick height is output (for example: the corrected maximum kick is 1.15 mm).

[0089] In a preferred embodiment, after the pose shaking vector sequence is formed, the following steps are further included:

[0090] determine whether each of the translation vectors in the pose jitter vector sequence can be decomposed into a height jitter component perpendicular to the reference plane;

[0091] Specifically, for each excessive jitter, determine its main direction: height direction: perpendicular to the mold surface, horizontal direction: parallel to the mold surface, if the main direction of the excessive jitter is the height direction, it is determined that the translation vector can be decomposed into a height jitter component.

[0092] The target three-dimensional point cloud data is spatiotemporally synchronized and corrected based on the pose jitter vector sequence to obtain corrected point cloud data, including the following steps:

[0093] If at least one of the translation vectors can be decomposed into the height jitter component, the target three-dimensional point cloud data is spatiotemporally synchronized and corrected based on the pose jitter vector sequence to obtain corrected point cloud data.

[0094] This embodiment considers that the jitter perpendicular to the mold surface (such as the up-and-down vibration of the equipment caused by the crane hoisting) has a greater impact on the reliability of calculating the reverse kick height, and the horizontal jitter such as the AGV tire bumping has a smaller impact, so the key jitter is processed specifically to optimize resources and reduce the amount of calculation.

[0095] Further, after determining whether each of the translation vectors can be decomposed into the height jitter component perpendicular to the reference plane, the following steps are further included: if all of the translation vectors cannot be decomposed into the height jitter component, output the measured reverse kick height.

[0096] In a preferred embodiment, if at least one of the translation vectors can be decomposed into the height jitter component, the target three-dimensional point cloud data is spatiotemporally synchronized and corrected based on the pose jitter vector sequence to obtain corrected point cloud data, including the following steps:

[0097] Decompose the translation vectors in the pose jitter vector sequence that can be decomposed into the height jitter component to obtain corresponding height jitter components to constitute a correction vector sequence, the correction vector sequence including a plurality of height jitter components and time stamps corresponding to each height jitter component;

[0098] Specifically, all jitter exceeding moments (e.g., ≥0.05mm) are screened from the IMU raw data, and each jitter vector is corrected. The specific process is as follows: the mold plane normal direction (pre-stored) is obtained, the projection length (i.e., the height jitter component) of the jitter in the normal direction is calculated, and the translation vector of the jitter exceeding the standard is exemplarily (0.1mm, -0.2mm, 0.3mm), and the mold normal is (0, 0, 1), corresponding to a horizontal mold, and the height component is 0.3mm (Z projection). The generated correction vector sequence (wherein a positive sign indicates upward jitter, and a negative sign indicates downward jitter) is shown in Table-1:

[0099] Table-1

[0100]

[0101] For each of the target point positions in the target three-dimensional point cloud data, the acquisition time corresponding to each of the target point positions is extracted;

[0102] The target point position corresponding to the acquisition time matching the timestamp in the correction vector sequence is taken as a point position to be corrected, and the acquisition time corresponding to the point position to be corrected is a target time;

[0103] The point position to be corrected is corrected by the height jitter component corresponding to the target time in the correction vector sequence, to obtain corrected point cloud data.

[0104] Specifically, for each scanning point, the acquisition time is queried, and the timestamp with a deviation of less than or equal to 0.001s from the acquisition time is searched in the correction vector sequence. If a match is found, the target point position scanned at this timestamp is corrected to obtain a corresponding corrected point position (if the height jitter component is positive, i.e., upward jitter, the Z coordinate of the original first spatial coordinate is reduced by the corresponding value of the height jitter component). If no match is found, the original coordinates are retained, and finally the corrected point cloud data composed of all the corrected point positions and the point positions retaining the original coordinates is output. Exemplarily: the point cloud acquisition time is 168920000.128ms, the jitter component is +0.08mm, and the correction calculation is to reduce the Z coordinate by 0.08mm. Create a new point cloud dataset: traverse all original point clouds: 90% of the points unaffected: directly copy the coordinates, 10% of the points to be corrected: update the Z value, and finally output the result.

[0105] In a preferred embodiment, after the calibration plane equation of the bearing plane is called, the following steps are further included:

[0106] If the continuous working time length of the lower mold is greater than or equal to a first preset time length, or the deviation amount of the real-time temperature of the temperature measuring point on the bearing plane from the normal temperature is greater than or equal to a first preset threshold, a temperature abnormal point is obtained;

[0107] Specifically, when the mold continuous working time ≥ 12h (first preset time length) or the temperature rise of any temperature measurement point of the bearing surface ≥ 10℃ (first preset threshold), a temperature abnormality processing procedure is triggered. The system automatically selects a temperature measurement point that meets any of the following conditions as a temperature abnormal point: located in the projection area directly below the edge portion (ensuring to cover the deformation sensitive area), or the temperature measurement point with the top 30% temperature rise deviation (focusing on the main heat affected zone). The temperature measurement point layout principle: according to the mold thermal deformation law, the temperature measurement points are arranged in a grid shape on the bearing surface (the spacing is ≤ 50mm), and the corresponding area of the edge portion is mainly encrypted. A buried PT100 platinum resistance temperature sensor is used to transmit real-time temperature data wirelessly.

[0108] According to the real-time temperature of the temperature abnormal point, an equivalent temperature rise is obtained;

[0109] Specifically, the equivalent temperature rise is calculated by the formula , wherein, is the equivalent temperature rise, ΔTi is the real-time temperature rise (current temperature-constant temperature 20℃) of the i-th temperature abnormal point, is a weight coefficient, which is determined by the importance of the measurement point position and the severity of the temperature rise, , wherein 0.7 represents the position weight, 0.3 represents the temperature weight, d i is the Euclidean distance (mm) from the measurement point to the nearest edge portion, and the closer the distance, the higher the weight, represents the maximum value of the real-time temperature rise ΔTi among all temperature abnormal points.

[0110] According to the equivalent temperature rise, the calibration plane equation is corrected to obtain a corrected plane equation;

[0111] Specifically, the thermal deformation mechanism: the thermal expansion coefficient α of the mold steel is approximately 12×10 -6 / ℃, and the normal displacement of the bearing surface caused by the temperature rise ΔT is: , L is the characteristic size (taking the maximum value in the length direction of the mold), and if the calibration plane equation is ax+by+cz+d=0, the constant term is updated to after correction, and the corrected plane equation is ax+by+cz+d n =0.

[0112] The plane corresponding to the corrected plane equation is taken as the reference plane.

[0113] Specifically, the embodiment realizes error compensation, for example, a temperature rise of 15.8℃ causes the mold bearing surface to rise by 0.226mm (thermal expansion upward bulging), the reference plane is moved upward after correction, the system error is eliminated, the precision and efficiency are improved (avoiding mold cooling downtime (the traditional scheme needs 2-4 hours), and the continuity of detection is improved.

[0114] Embodiment 2

[0115] On the basis of embodiment 1, the embodiment proposes a new energy automobile high-strength steel plate edge portion anti-lifting measurement system, which is used to realize the new energy automobile high-strength steel plate edge portion anti-lifting measurement method as described above, as shown in the figure, which comprises: Figure 2

[0116] The calling module is configured to obtain the edge portion region of the steel plate to be detected according to the steel plate type of the steel plate to be detected;

[0117] The monitoring module is configured to monitor the stamping process signal of the steel plate to be detected in real time, and determine whether to trigger the anti-lifting measurement of the edge portion region according to the stamping process signal;

[0118] The measurement module is configured to scan the edge portion region of the steel plate carried on the lower die if so, and obtain target three-dimensional point cloud data of the edge portion region, the target three-dimensional point cloud data comprising a plurality of target points on the edge portion region and first spatial coordinates of each target point.

[0119] The measurement module is further configured to project the target three-dimensional point cloud data to the reference plane by taking the bearing plane of the lower die as the reference plane, and calculate the first normal distance of each target point to the reference plane; and take the maximum first normal distance as the measured anti-lifting height.

[0120] In summary, the rebound amount of high-strength steel plate (DP980 / MS1500) is 3-5 times that of ordinary steel plate, and the anti-lifting detection precision is controlled within 1% of the material yield strength, which meets the edge deformation detection requirements of new materials such as laser welding plate and hot forming steel (22MnB5).

[0121] In this paper, specific examples are used to illustrate the principles and implementation methods of the application. The above examples are only used to help understand the method and its core idea. The above description is only the preferred embodiment of the application. It should be pointed out that due to the limitation of language expression, there are infinite specific structures, and for ordinary technical personnel in this technical field, without departing from the principles of the application, some improvements, refinements or changes can be made, and the above technical features can be combined in a proper way; these improvements, refinements, changes or combinations, or the application of the concept and technical scheme of the application to other occasions without improvement, shall be regarded as the protection scope of the application.​

Claims

1. A method for measuring the reverse lifting of the edge portion of a high-strength steel sheet for a new energy vehicle, characterized by, The method comprises the following steps: According to the type of the steel plate to be detected, the edge region of the steel plate to be detected is obtained; Real-time monitoring of the stamping process signal of the steel plate to be detected, according to the stamping process signal, judging whether to trigger the reverse kick measurement of the edge region or not; If yes, the edge region of the steel plate carried on the lower die is scanned, the target three-dimensional point cloud data of the edge region is obtained, the target three-dimensional point cloud data includes a plurality of target points on the edge region, and the first spatial coordinates of each target point; The carrying plane of the lower die is taken as the reference plane, the target three-dimensional point cloud data is projected onto the reference plane, and the first normal distance of each target point to the reference plane is calculated; The maximum first normal distance is taken as the measured reverse kick height; The carrying plane of the lower die is taken as the reference plane, which comprises the following steps: The preset calibration plane equation of the carrying plane is called, and the calibration plane equation is obtained at normal temperature; If the continuous working time of the lower die is less than the first preset time, and the deviation of the real-time temperature of the plurality of temperature measuring points on the carrying plane from the normal temperature is less than the first preset threshold, the plane corresponding to the calibration plane equation is taken as the reference plane; After the preset calibration plane equation of the carrying plane is called, the following steps are further included: If the continuous working time of the lower die is greater than or equal to the first preset time, or the deviation of the real-time temperature of the temperature measuring point on the carrying plane from the normal temperature is greater than or equal to the first preset threshold, a temperature abnormal point is obtained; According to the real-time temperature of the temperature abnormal point, an equivalent temperature rise is obtained; According to the equivalent temperature rise, the calibration plane equation is corrected to obtain a corrected plane equation; The plane corresponding to the corrected plane equation is taken as the reference plane.

2. The method according to claim 1, wherein the method is a method for measuring the reverse curling of a high-strength steel sheet for a new energy vehicle. The stamping process signal includes the slider displacement encoder signal of the punch press; According to the stamping process signal, whether to trigger the reverse kick measurement of the edge region is judged, which comprises the following steps: Based on the slider displacement encoder signal, it is judged whether the upper die has risen to a preset opening safety height; If yes, it is determined that the reverse kick measurement of the edge region is triggered.

3. The method according to claim 2, wherein the method is characterized by: The edge region is scanned by a non-contact scanning device, the non-contact scanning device is a line laser scanner installed on a movable device that can move to a measurement position, and an inertial measurement unit is arranged on the movable device to measure the six-degree-of-freedom pose change data of the line laser scanner in real time during scanning; After the maximum first normal distance is taken as the measured reverse kick height, the following steps are further included: The six-degree-of-freedom pose change data is called to generate a pose jitter data set, the pose jitter data set includes a plurality of time stamp corresponding translation vectors; The length of each translation vector is calculated to obtain the corresponding pose jitter amplitude; If all the pose jitter amplitudes are less than a preset jitter threshold, the measured reverse kick height is output.

4. The method according to claim 3, wherein the method is characterized by: After the corresponding pose jitter amplitude is obtained, the following steps are further included: If at least one of the pose jitter amplitudes is greater than or equal to a preset jitter threshold, a translation vector corresponding to the pose jitter amplitude greater than or equal to the preset jitter threshold is extracted, and a corresponding timestamp is extracted to form a pose jitter vector sequence; Based on the pose jitter vector sequence, the target three-dimensional point cloud data is corrected in space-time synchronization to obtain corrected point cloud data; Projecting the corrected point cloud data onto the reference plane, calculating the second normal distance of each point in the edge portion to the reference plane; The maximum second normal distance is taken as the corrected reverse kick height and output.

5. The method according to claim 4, wherein the method is characterized by: After the pose jitter vector sequence is formed, the following steps are further included: Determine whether each translation vector in the pose jitter vector sequence can be decomposed into a height jitter component perpendicular to the reference plane; Based on the pose jitter vector sequence, the target three-dimensional point cloud data is corrected in space-time synchronization to obtain corrected point cloud data, including the following steps: If at least one of the translation vectors can be decomposed into the height jitter component, the target three-dimensional point cloud data is corrected in space-time synchronization according to the pose jitter vector sequence to obtain corrected point cloud data.

6. The method according to claim 5, wherein the method is characterized in that: After determining whether each translation vector can be decomposed into a height jitter component perpendicular to the reference plane, the following steps are further included: If all the translation vectors cannot be decomposed into the height jitter component, the measured reverse kick height is output.

7. The method according to claim 5, wherein the method is characterized by: If at least one of the translation vectors can be decomposed into the height jitter component, the target three-dimensional point cloud data is corrected in space-time synchronization according to the pose jitter vector sequence to obtain corrected point cloud data, including the following steps: Decompose the translation vectors in the pose jitter vector sequence that can be decomposed into the height jitter component to obtain the corresponding height jitter component to form a correction vector sequence, the correction vector sequence including multiple height jitter components and timestamps corresponding to each height jitter component; For each target point in the target three-dimensional point cloud data, the collection time corresponding to each target point is extracted; The target point corresponding to the collection time matching the timestamp in the correction vector sequence is taken as a point to be corrected, and the collection time corresponding to the point to be corrected is taken as a target time; The height jitter component corresponding to the target time in the correction vector sequence is used to correct the point to be corrected to obtain corrected point cloud data.

8. A system for measuring the reverse buckling of the edge portion of a high-strength steel sheet for a new energy vehicle, for implementing the method for measuring the reverse buckling of the edge portion of a high-strength steel sheet for a new energy vehicle according to any one of claims 1 to 7, characterized in that: It includes: The calling module is configured to obtain the edge portion region of the steel plate to be detected according to the type of the steel plate to be detected; The monitoring module is configured to monitor the stamping process signal of the steel plate to be detected in real time, and determine whether to trigger the reverse kick measurement of the edge portion region according to the stamping process signal; The measurement module is configured to scan the edge portion region of the steel plate carried on the lower die if so, and obtain target three-dimensional point cloud data of the edge portion region, the target three-dimensional point cloud data including a plurality of target points on the edge portion region and first spatial coordinates of each target point; The measurement module is further configured to take the bearing plane of the lower mold as a reference plane, project the target three-dimensional point cloud data to the reference plane, and calculate a first normal distance of each target point to the reference plane; and take the maximum first normal distance as the measured anti-warping height.

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