Automatic measurement operation method and system for automobile wire harness production detection

Abstract

The invention discloses an automatic measurement operation method and system for automobile wire harness production detection, and relates to the technical field of automobile manufacturing, and the method comprises the steps: determining the initial spatial position relation of each connection point relative to an adjacent connection point according to an initial position coordinate, and determining the connection points with offset positions and a local region formed by the adjacent connection points, correcting the positions of the connection points in the local area in sequence according to a wire harness assembly process sequence to obtain corrected position coordinates; under the condition that the correction position coordinates do not conform to the initial spatial position relation, finely adjusting the connection points according to the maximum bending radius of the wire harness material to restore the positions of the connection points to the initial spatial position relation, determining an actual measurement path according to the actual spatial bending form of each branch section, and measuring the actual length of each branch section; according to the invention, accurate measurement of the spatial position of the connection point of the automobile wire harness and the actual length of the branch section is realized, and the accuracy and reliability of automobile wire harness assembly are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile manufacturing, and in particular to an automatic measurement operation method and system for automobile wiring harness production detection. Background Art

[0002] With the rapid development of automotive manufacturing technology, the complexity and assembly precision requirements of automotive electrical systems continue to increase. As a key component of automotive electrical systems, the assembly precision of the wiring harness is directly related to the electrical performance and reliability of the entire vehicle. Automotive wiring harnesses typically consist of multiple branch segments, each connected by multiple connection points. During the actual production and assembly process, the flexible material properties of the wiring harness, external forces during transportation, differences in assembly processes, and human factors often lead to significant offsets in the actual spatial positions of each connection point. This in turn affects the overall spatial layout of the wiring harness and the accurate measurement of branch segment lengths, resulting in assembly errors and even failure.

[0003] Existing methods for measuring wire harness length typically rely on manual linear measurement or simple straightening, failing to fully account for the complex spatial curvature of the wire harness during actual assembly. This leads to significant discrepancies between the measured results and the actual assembly, impacting assembly quality. In particular, in the on-site assembly of automotive wiring harnesses, connection point offsets not only affect the precise positioning of individual connection points but also the initial spatial relationship between adjacent connection points, further impacting the accuracy of measuring the actual length of branch segments. Traditional methods are unable to effectively identify connection point offsets or fine-tune connection points based on the actual bending properties of the harness material, making it difficult to meet the high-precision requirements of modern automotive wiring harness assembly.

[0004] Therefore, there is an urgent need for a method that can accurately determine the initial spatial position of each connection point in the free state of the automobile wiring harness, detect the connection point offset in real time, and accurately correct and fine-tune the connection point position according to the bending performance of the wiring harness material. Summary of the Invention

[0005] The purpose of the present invention is to provide an automatic measurement method and system for automobile wiring harness production inspection to solve the problems in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides an automatic measurement method for automobile wiring harness production inspection, comprising:

[0008] S101: placing a to-be-tested automotive wiring harness having a plurality of branch segments and a plurality of branch connection points on a measurement platform, wherein a plurality of spatial reference points are preset on the measurement platform, and without fixing the wiring harness, measuring the initial position coordinates of each branch connection point relative to the spatial reference point, and determining the initial spatial position relationship of each connection point relative to an adjacent connection point based on the initial position coordinates;

[0009] S102: When the position offset of the branch connection point exceeds the allowable range and the initial spatial position relationship of adjacent connection points is changed, a local area consisting of the connection point with the position offset and adjacent connection points is determined, and the positions of the connection points in the local area are sequentially corrected according to the wiring harness assembly process sequence to obtain corrected position coordinates;

[0010] S103: When the corrected position coordinates do not conform to the initial spatial position relationship, fine-tune the connection point according to the maximum bending radius of the harness material to restore the connection point position to the initial spatial position relationship;

[0011] S104: After the connection point positions are restored to the initial spatial position relationship, an actual measurement path is determined according to the actual spatial bending shape of each branch segment, and the actual length of each branch segment is measured.

[0012] Furthermore, determining the initial spatial position relationship of each connection point relative to adjacent connection points includes:

[0013] Select three or more non-collinear spatial reference points on the measurement platform as the measurement reference;

[0014] Measuring the initial spatial distance between each branch connection point and the spatial reference point to obtain a plurality of initial spatial distance values;

[0015] Calculate the initial three-dimensional position coordinates of each branch connection point according to multiple initial spatial distance values;

[0016] The initial spatial distance and initial spatial relative angle between each pair of adjacent connection points are calculated and recorded according to the three-dimensional position coordinates of the two adjacent connection points as the initial relative spatial position relationship between the adjacent connection points.

[0017] Furthermore, the calculation of the initial three-dimensional position coordinates of each branch connection point includes:

[0018] Determine a spatial coordinate system on the measurement platform using the three or more non-collinear spatial reference points;

[0019] By measuring the initial spatial distance between each branch connection point and the spatial reference point, the initial distance relationship between the connection point and each spatial reference point in the spatial coordinate system is determined;

[0020] Calculate the initial coordinate position of each connection point using the initial distance relationship of each connection point relative to the spatial reference point;

[0021] The calculated initial coordinate position is used as the initial three-dimensional position coordinate of each branch connection point.

[0022] Furthermore, the calculation of the initial coordinate position of each connection point includes:

[0023] Determine the spatial relationship between various spatial reference points based on the spatial coordinate system of the measurement platform;

[0024] Based on the initial spatial distances from the branch connection points to each spatial reference point, calculate the distance projections of each connection point on each coordinate axis of the spatial coordinate system;

[0025] The three-dimensional position of each connection point in the spatial coordinate system is determined by using the distance projection of each connection point on each coordinate axis;

[0026] The determined three-dimensional position is recorded as the initial coordinate position of each connection point.

[0027] Furthermore, obtaining the corrected position coordinates includes:

[0028] Determine the actual position coordinates of the connection point that is offset and each connection point within a local adjustment area formed by a plurality of adjacent connection points;

[0029] According to the automotive wiring harness assembly process requirements, determine the assembly sequence of each connection point in the local adjustment area in the vehicle assembly;

[0030] Determine the target position coordinates of each connection point in the local adjustment area in sequence according to the assembly sequence;

[0031] Compare the differences between the actual position coordinates and the target position coordinates, adjust the position of each connection point one by one according to the assembly sequence until the actual position coordinates of each connection point are the same as the target position coordinates, and output the adjusted actual position coordinates as the corrected position coordinates.

[0032] Furthermore, determining the target position coordinates of each connection point in the local adjustment area includes:

[0033] Record the actual installation path of the wiring harness during the automobile assembly process and identify the specific vehicle body installation locations involved in the installation path;

[0034] Determine the specific installation position of each branch connection point within the vehicle body space based on the identified vehicle body installation location;

[0035] Taking the preset installation reference point in the vehicle body as the reference, measure the three-dimensional spatial coordinates of each connection point relative to the installation reference point;

[0036] The measured three-dimensional spatial position coordinates are recorded as the target position coordinates of each connection point.

[0037] Furthermore, the fine-tuning of the connection point according to the maximum bending radius of the wiring harness material includes:

[0038] Measure the actual spatial position of each connection point after position correction;

[0039] Determine the maximum allowable bending radius based on the bending performance index of the wire harness material;

[0040] Determine the specific spatial area that each connection point can be adjusted with the maximum allowable bending radius as the constraint;

[0041] In a specific spatial area, fine-tune the position of each connection point one by one to the required position coordinates of the initial relative spatial position relationship.

[0042] Furthermore, determining the actual measurement path according to the actual spatial bending shape of each branch segment and measuring the actual length of each branch segment includes:

[0043] Record the actual spatial bending position of each branch segment;

[0044] Each branch segment is divided into multiple continuous measurement segments according to the recorded spatial bending positions;

[0045] Determine the actual measurement path for each measurement segment;

[0046] The actual length of each measured segment is measured segment by segment and accumulated to obtain the actual length of each branch segment.

[0047] In a second aspect, the present invention provides an automatic measurement system for automobile wiring harness production testing, which is implemented based on the above-mentioned automatic measurement method for automobile wiring harness production testing, and includes:

[0048] A measurement preprocessing module is used to place a to-be-tested automotive wiring harness having multiple branch segments and multiple branch connection points on a measurement platform, the measurement platform being pre-set with multiple spatial reference points, and to measure the initial position coordinates of each branch connection point relative to the spatial reference point without fixing the wiring harness, and to determine the initial spatial position relationship of each connection point relative to adjacent connection points based on the initial position coordinates;

[0049] A data correction module is used to determine the local area consisting of the branch connection point and adjacent connection points where the position offset exceeds the allowable range and the initial spatial position relationship of the adjacent connection points is changed, and to correct the positions of the connection points in the local area in sequence according to the wiring harness assembly process sequence to obtain the corrected position coordinates;

[0050] An information adjustment module is used to fine-tune the connection point according to the maximum bending radius of the harness material when the correction position coordinates do not conform to the initial spatial position relationship, so as to restore the connection point position to the initial spatial position relationship;

[0051] The data measurement module is used to determine the actual measurement path and measure the actual length of each branch segment based on the actual spatial bending shape of each branch segment after the connection point position is restored to the initial spatial position relationship.

[0052] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0053] The present invention effectively avoids the measurement errors caused by external force constraints in traditional harness measurement methods by accurately measuring the initial spatial position relationship of each connection point in a free state without fixing the harness, significantly improves the accuracy and reliability of determining the initial position of the connection point, and provides an accurate and reliable reference basis for subsequent assembly.

[0054] The present invention detects the offset of the connection point position in real time and accurately corrects and fine-tunes the connection point position based on the maximum allowable bending radius of the automobile wiring harness material, effectively solving the problem of failure of the spatial position relationship of adjacent connection points caused by the offset of the connection point position, ensuring the spatial position accuracy of the wiring harness and significantly reducing the failure risk during the wiring harness assembly process.

[0055] The present invention uses three-dimensional point cloud scanning and cubic B-spline curve fitting technology to accurately determine the actual measurement path of the branch segment based on the actual spatial bending shape of the wiring harness, and accurately measures the actual length of each branch segment. It effectively solves the measurement inaccuracy problem caused by traditional linear measurement or straightening measurement methods, makes the wiring harness length measurement result highly consistent with the actual assembly state, and significantly improves the accuracy and reliability of automobile wiring harness assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0057] Figure 1 This is a flow chart of an automatic measurement method for automobile wiring harness production inspection according to the present invention;

[0058] Figure 2 This is a framework diagram of an automatic measurement system for automobile wiring harness production and testing according to the present invention. DETAILED DESCRIPTION

[0059] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be more comprehensive and complete, and will fully convey the concepts of the example embodiments to those skilled in the art. The accompanying drawings are merely schematic illustrations of the disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures indicate identical or similar parts, and thus any repetitive description thereof will be omitted.

[0060] In addition, the described features, structures or characteristics can be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments disclosed in this application. However, those skilled in the art will appreciate that the technical solutions disclosed in this application can be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. can be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring the various aspects disclosed in this application.

[0061] Example 1

[0062] like Figure 1 As shown, this embodiment discloses an automatic measurement method for automobile wiring harness production inspection, including:

[0063] S101: placing a to-be-tested automotive wiring harness having a plurality of branch segments and a plurality of branch connection points on a measurement platform, wherein a plurality of spatial reference points are preset on the measurement platform, and without fixing the wiring harness, measuring the initial position coordinates of each branch connection point relative to the spatial reference point, and determining the initial spatial position relationship of each connection point relative to an adjacent connection point based on the initial position coordinates;

[0064] In this embodiment, the automotive wiring harness to be tested is selected from a mass-produced vehicle model. The total length of the wiring harness is 1800 mm, including 4 branch segments, specifically the engine control unit (ECU) branch, the headlight branch, the air-conditioning compressor branch, and the battery grounding branch. The diameter of each branch segment is approximately 6 to 10 mm, and 6 branch connection points are formed between the branch segments by crimping. The connection points are numbered P1 to P6.

[0065] In the specific implementation, the above-mentioned automotive wiring harness is placed on a rectangular aluminum alloy measurement platform with dimensions of 2000mm (length) × 1500mm (width) × 800mm (height). The surface flatness of the measurement platform is ≤±0.05mm. Four spatial reference points are preset on the platform surface as measurement reference points, respectively set at the four corners of the platform, and the coordinate values ​​are strictly as follows:

[0066] Spatial reference point A: (0mm, 0mm, 0mm);

[0067] Spatial reference point B: (2000mm, 0mm, 0mm);

[0068] Spatial reference point C: (0mm, 1500mm, 0mm);

[0069] Spatial reference point D: (0mm, 0mm, 800mm);

[0070] When the wire harness is placed on the measuring platform, no clamps or fixtures are used to fix the wire harness. The wire harness is in a completely free state on the platform surface, and each connection point can move freely without any external force constraints.

[0071] In implementation, determining the initial spatial position relationship of each connection point relative to adjacent connection points includes:

[0072] Select three or more non-collinear spatial reference points on the measurement platform as the measurement reference;

[0073] Specifically, among the four spatial reference points A, B, C, and D of the measurement platform, any three non-collinear reference points are selected as measurement references. For example, reference points A, B, and C are selected as reference measurement points for all subsequent measurements and calculations.

[0074] Measuring the initial spatial distance between each branch connection point and the spatial reference point to obtain a plurality of initial spatial distance values;

[0075] Specifically, a high-precision laser rangefinder (distance measurement accuracy ±0.02mm) is used to measure the initial spatial distances from each branch connection point P1 to P6 of the wiring harness to the above-mentioned spatial reference points A, B, and C respectively;

[0076] An example of recording the measured values ​​of connection point P1 is as follows:

[0077] Initial distance from connection point P1 to reference point A: L_P1A = 635.2 mm;

[0078] Initial distance from connection point P1 to reference point B: L_P1B = 1562.5 mm;

[0079] The initial distance from the connection point P1 to the reference point C is: L_P1C=742.3mm.

[0080] Calculate the initial three-dimensional position coordinates of each branch connection point according to multiple initial spatial distance values;

[0081] Specifically, the calculation of the initial three-dimensional position coordinates of each branch connection point includes:

[0082] Determine a spatial coordinate system on the measurement platform using the three or more non-collinear spatial reference points;

[0083] Specifically, a spatial rectangular coordinate system is established based on the three spatial reference points A, B, and C on the measuring platform, wherein the reference point A is the coordinate origin O (0mm, 0mm, 0mm), the straight line direction from the reference point A to B is the positive direction of the X-axis, the straight line direction from the reference point A to C is the positive direction of the Y-axis, and the normal direction of the measuring platform perpendicular to the ABC plane is the positive direction of the Z-axis.

[0084] By measuring the initial spatial distance between each branch connection point and the spatial reference point, the initial distance relationship between the connection point and each spatial reference point in the spatial coordinate system is determined;

[0085] For example, taking the connection point P1 as an example, based on the initial spatial distance values ​​(L_P1A, L_P1B, L_P1C) measured from the connection point P1 to the three spatial reference points A, B, and C, the initial distance relationship of the connection point P1 in the spatial coordinate system is calculated.

[0086] Calculate the initial coordinate position of each connection point using the initial distance relationship of each connection point relative to the spatial reference point;

[0087] Specifically, the calculation of the initial coordinate position of each connection point includes:

[0088] Determine the spatial relationship between various spatial reference points based on the spatial coordinate system of the measurement platform;

[0089] Specifically, the spatial relationship between the reference points is known: reference point A (0, 0, 0), reference point B (2000 mm, 0, 0), and reference point C (0, 1500 mm, 0).

[0090] Based on the initial spatial distances from the branch connection points to each spatial reference point, calculate the distance projections of each connection point on each coordinate axis of the spatial coordinate system;

[0091] For example, taking the connection point P1 as an example, based on the initial distance value from the connection point to the reference point, its coordinate projection position on the X-axis and Y-axis is calculated using the following formula:

[0092] X-axis coordinate projection position calculation:

[0093]

[0094] Y-axis coordinate projection position calculation:

[0095]

[0096] Among them, L_AB=2000mm, L_AC=1500mm (platform size); L_P1A, L_P1B, L_P1C are measurement data.

[0097] The three-dimensional position of each connection point in the spatial coordinate system is determined by using the distance projection of each connection point on each coordinate axis;

[0098] Taking P1 as an example, the X and Y coordinate values ​​are calculated as follows: X_P1 ​​= 620.4 mm, Y_P1 = 630.2 mm, and the vertical height from P1 to the platform plane (i.e., the Z-axis coordinate) is further measured using a laser rangefinder, Z_P1 = 568.3 mm, with a measurement accuracy of ±0.05 mm.

[0099] Record the determined three-dimensional position as the initial coordinate position of each connection point;

[0100] The calculated and measured spatial coordinate values ​​(X_P1, Y_P1, Z_P1) = (620.4mm, 630.2mm, 568.3mm) are accurately recorded as the initial three-dimensional position coordinates of the connection point P1. The coordinates of the other connection points P2 to P6 are calculated and recorded using the same method.

[0101] The calculated initial coordinate position is used as the initial three-dimensional position coordinate of each branch connection point;

[0102] Specifically, taking the connection point P1 (X1, Y1, Z1) and the adjacent connection point P2 (X2, Y2, Z2) as an example, calculate the initial spatial distance L_P1P2 between the two:

[0103]

[0104] Calculate the initial spatial relative angle θ between the connection points P1 and P2. The calculation formula is the angle between the connection line and the X-axis:

[0105]

[0106] Record the initial spatial distance and initial relative angle in the data table. For example, the initial distance between P1 and P2 is recorded as L_P1P2=755.6mm, and the relative angle is recorded as θ=62.5°. Other connection points are processed similarly.

[0107] Calculate and record the initial spatial distance and initial spatial relative angle between each pair of adjacent connection points based on the three-dimensional position coordinates of the two adjacent connection points as the initial relative spatial position relationship between the adjacent connection points;

[0108] S102: When the position offset of the branch connection point exceeds the allowable range and the initial spatial position relationship of adjacent connection points is changed, a local area consisting of the connection point with the position offset and adjacent connection points is determined, and the positions of the connection points in the local area are sequentially corrected according to the wiring harness assembly process sequence to obtain corrected position coordinates;

[0109] The purpose of this step is to: when the position of one or more branch connection points of the wiring harness is significantly offset, and the initial spatial position relationship between it and the adjacent connection points is changed, it is necessary to promptly perform local position correction to ensure that the wiring harness assembly quality meets the vehicle assembly process requirements;

[0110] Specifically, the set connection point position offset allowable threshold is ±5mm, and the spatial position relationship between adjacent connection points allows an error range of ±2° or ±5mm; when the position deviation of the connection point obtained by actual measurement exceeds (is greater than or equal to) the above allowable range, this step needs to be started for position correction.

[0111] In implementation, obtaining the corrected position coordinates includes:

[0112] Determine the actual position coordinates of the connection point that is offset and each connection point within a local adjustment area formed by a plurality of adjacent connection points;

[0113] In a specific implementation, a high-precision three-dimensional laser rangefinder (measurement accuracy ±0.02mm) is used to re-measure the current actual position coordinates of each connection point of the wiring harness, and compared with the initial position coordinates determined in step S101 to determine whether position offset occurs.

[0114] Specifically, taking the connection point P2 as an example, step S101 determines that the initial position coordinates of the connection point P2 are (620.5mm, 630.0mm, 568.5mm). The current actual position coordinates of the connection point P2 are measured in real time at the actual production site, and the measurement data are (625.8mm, 636.4mm, 569.9mm). The coordinate deviation is calculated as follows:

[0115] Deviation in the X-axis direction: ΔX = 625.8 mm - 620.5 mm = +5.3 mm;

[0116] Y-axis deviation: ΔY = 636.4 mm - 630.0 mm = + 6.4 mm;

[0117] Deviation in the Z-axis direction: ΔZ = 569.9 mm - 568.5 mm = +1.4 mm.

[0118] The above calculation results clearly show that the deviation of the actual position coordinates of the connection point P2 in the X and Y directions exceeds the prescribed allowable threshold of ±5 mm, which is a case of obvious deviation.

[0119] In order to further determine whether the initial spatial position relationship of adjacent connection points has changed, the above-mentioned distance meter is used to measure the actual spatial distance and relative angle between the connection point P2 and the adjacent connection points P1 and P3, and compare them with the initial values ​​recorded in step S101; specific measurement data are as follows:

[0120] The initial spatial distance between connection points P1 and P2 is 750.0 mm, and the actual measured distance is 755.5 mm; the initial relative angle is 60.0°, and the actual measured angle is 62.0°;

[0121] The initial spatial distance between connection points P2 and P3 is 650.0 mm, and the actual measured distance is 656.5 mm; the initial relative angle is 45.0°, and the actual measured angle is 47.3°.

[0122] It can be seen from the above measurement data that the position offset of connection point P2 causes the change in the initial spatial position relationship between it and the adjacent connection points to exceed the allowable range (distance change exceeds ±5mm, angle change exceeds ±2°).

[0123] Therefore, the connection point P2 is determined to be the connection point where the specific position is offset, and the adjacent connection points P1 and P3 are divided into the area of ​​this local adjustment, and further position correction is required.

[0124] According to the automotive wiring harness assembly process requirements, determine the assembly sequence of each connection point in the local adjustment area in the vehicle assembly;

[0125] The "automobile wiring harness assembly process requirements" mentioned in this embodiment refer to the installation sequence and installation position of each connection point in the vehicle assembly space specified in the automobile wiring harness design drawings, specifically including the installation order of each connection point, the relative position relationship between the installation point and the vehicle body fixing bracket, the allowable error range of the installation position (±0.1mm to ±0.5mm), etc.; these assembly process requirements are derived from the "Wire Harness Assembly Process Specification Document" and "Wire Harness Assembly Process Drawings" provided by the wiring harness design department, and are technical documents that are strictly followed during the vehicle assembly process.

[0126] During the specific implementation process, according to the above-mentioned automotive wiring harness assembly process requirements, the assembly order of each connection point in this local adjustment area (including connection points P1, P2, and P3) is determined as follows:

[0127] The first order is connection point P1 (corresponding to the vehicle engine ECU terminal installation position);

[0128] The second order is connection point P2 (corresponding to the engine sensor branch installation position);

[0129] The third order is connection point P3 (corresponding to the air-conditioning compressor branch installation position).

[0130] The above assembly sequence has been recorded in the automotive wiring harness assembly process specification document. When implementing it, the technicians must strictly follow the sequence to perform position correction point by point.

[0131] Determine the target position coordinates of each connection point in the local adjustment area in sequence according to the assembly sequence;

[0132] Specifically, determining the target position coordinates of each connection point in the local adjustment area includes:

[0133] Record the actual installation path of the wiring harness during the automobile assembly process and identify the specific vehicle body installation locations involved in the installation path;

[0134] Based on the specific conditions of the vehicle assembly site, on-site technicians recorded the actual installation path of the wiring harness through manual observation, measurement, and recording. The path is: from the vehicle body through the hole on the left side of the engine compartment, through the left headlight fixing bracket, the engine rear end fixing bracket, and finally to the terminal bracket position of the air conditioning compressor;

[0135] At the same time, identify the specific vehicle body installation locations involved in the installation path and record their spatial coordinate values:

[0136] The coordinates of the center position of the vehicle body through hole are (350mm, 200mm, 800mm);

[0137] The center coordinates of the left headlight bracket mounting hole are (800mm, 400mm, 750mm);

[0138] The center coordinates of the engine rear end bracket mounting holes are (1200mm, 700mm, 850mm);

[0139] The center coordinates of the air conditioning compressor bracket installation position are (1600mm, 900mm, 650mm).

[0140] The above position coordinates are given by the design drawings provided by the wire harness design engineer and are verified and confirmed by the on-site three-coordinate measuring instrument (measuring accuracy ±0.01mm) to ensure that the coordinate accuracy is within ±0.1mm.

[0141] Determine the specific installation position of each branch connection point within the vehicle body space based on the identified vehicle body installation location;

[0142] Based on the identified and confirmed spatial coordinates of the vehicle body installation part, the specific installation position coordinates of each connection point in the local adjustment area in the vehicle are determined respectively.

[0143] Taking connection point P2 as a specific example, based on the coordinate position of the center of the mounting hole of the engine rear end fixing bracket (X=1200mm, Y=700mm, Z=850mm), the target installation position coordinates of connection point P2 are determined by calculation as follows: X-axis coordinate: 620.5mm; Y-axis coordinate: 630.0mm; Z-axis coordinate: 568.5mm;

[0144] The above target position coordinates are given by the wiring harness installation drawings provided by the design department and have been confirmed on site by three-coordinate measuring equipment with a measurement accuracy within ±0.1mm.

[0145] Taking the preset installation reference point in the vehicle body as the reference, measure the three-dimensional spatial coordinates of each connection point relative to the installation reference point;

[0146] A unified installation reference point Q is pre-determined inside the vehicle body as a measurement reference. The reference point Q is located on the left longitudinal beam at the front end of the vehicle body, and its coordinates are (X=0mm, Y=0mm, Z=0mm). Using the reference point Q as a measurement reference, a FARO Laser Tracker Vantage high-precision laser rangefinder is used to actually measure and confirm the target installation position coordinates of each connection point again.

[0147] Specifically, taking the connection point P2 as an example, the target position coordinates obtained by measurement are: X-axis coordinate: 620.5mm; Y-axis coordinate: 630.0mm; Z-axis coordinate: 568.5mm;

[0148] The measurement results are completely consistent with the coordinates determined by the above calculations, and the measurement accuracy is controlled within ±0.05mm, confirming that the coordinates are accurate and valid.

[0149] The measured three-dimensional spatial position coordinates are recorded as the target position coordinates of each connection point;

[0150] The target position coordinates of each connection point obtained from the above measurement are clearly and accurately recorded to form a standardized data table. Taking connection point P2 as an example, its target position coordinates are recorded as (620.5mm, 630.0mm, 568.5mm). The same method is used to confirm and record the target positions of other connection points (P1, P3) in the local adjustment area to ensure that the data is clear and can be used for subsequent position adjustments.

[0151] Compare the differences between the actual position coordinates and the target position coordinates, adjust the position of each connection point one by one according to the assembly sequence until the actual position coordinates of each connection point are the same as the target position coordinates, and output the adjusted actual position coordinates as the corrected position coordinates;

[0152] The purpose of this step is to correct the connection point coordinates that have deviations in the actual position to the target position coordinates to ensure that the connection point position meets the actual assembly requirements of the automotive wiring harness. The specific implementation process is disclosed as follows:

[0153] First, the actual position coordinates of each connection point obtained by actual measurement are compared with the recorded target position coordinates one by one to clearly calculate the position difference.

[0154] Taking the connection point P2 as an example, the actual position coordinates are (625.8mm, 636.4mm, 569.9mm) and the target position coordinates are (620.5mm, 630.0mm, 568.5mm). The difference between the two is calculated as follows:

[0155] The position difference in the X-axis direction is: ΔX = 620.5mm - 625.8mm = -5.3mm;

[0156] The position difference in the Y-axis direction is: ΔY = 630.0 mm - 636.4 mm = -6.4 mm;

[0157] The position difference in the Z-axis direction is: ΔZ = 568.5mm - 569.9mm = -1.4mm;

[0158] The above calculation results clearly show that the adjustment amounts of the actual position coordinates of the connection point P2 in the X, Y, and Z axis directions are -5.3mm, -6.4mm, and -1.4mm, respectively, and the adjustment position accuracy is required to be controlled within ±0.05mm.

[0159] Subsequently, an ABBIRB2400 industrial robot (six-axis robot, position adjustment accuracy ±0.05mm) was used for precise position adjustment. The specific implementation is as follows:

[0160] Based on the specific adjustment amount calculated above, the technician enters the following adjustment instruction parameters into the robot position adjustment program:

[0161] Move 5.3mm along the negative direction of the X axis;

[0162] Move 6.4mm along the negative direction of the Y axis;

[0163] Move 1.4mm along the negative direction of the Z axis;

[0164] Start the robot program and monitor the position adjustment process in real time until the position coordinates of the connection point P2 accurately reach the target position coordinates.

[0165] After the position adjustment is completed, the actual position of connection point P2 is remeasured using the FARO LaserTracker Vantage high-precision laser rangefinder. The measurement results show that the position coordinates of connection point P2 are exactly the same as the target position coordinates, which are (620.5mm, 630.0mm, 568.5mm), and the measurement accuracy is controlled within ±0.05mm, confirming that the calibration is complete.

[0166] Finally, the actual position coordinates after the above correction (620.5mm, 630.0mm, 568.5mm) are output and recorded and stored in the standardized wire harness quality inspection data table; other connection points in the local adjustment area (such as connection points P1 and P3) are corrected and remeasured one by one according to the same method and steps to ensure that the position coordinates of all connection points fully meet the design target position coordinate requirements.

[0167] S103: When the corrected position coordinates do not conform to the initial spatial position relationship, fine-tune the connection point according to the maximum bending radius of the harness material to restore the connection point position to the initial spatial position relationship;

[0168] The purpose of implementing this step is: after completing the connection point position correction in step S102, if the actual position of the connection point has not yet fully recovered to the range of the initial spatial position relationship, it is necessary to accurately fine-tune the connection point according to the maximum bending radius of the automotive wiring harness material so that the position of the connection point fully meets the initial spatial position relationship requirements of the wiring harness assembly.

[0169] In implementation, the fine-tuning of the connection point according to the maximum bending radius of the harness material includes:

[0170] Measure the actual spatial position of each connection point after position correction;

[0171] After completing the position correction in step S102, a high-precision three-dimensional laser rangefinder (measurement accuracy ±0.02 mm) is used to re-measure and confirm the actual position coordinates of each corrected connection point.

[0172] For example, taking the connection point P2 as a specific example, the actual position coordinate measurement value of the connection point P2 after correction is (620.8mm, 630.3mm, 568.7mm), which still does not fully reach the accurate value of the initial position coordinate (620.5mm, 630.0mm, 568.5mm) in step S101. The deviation is:

[0173] ΔX=620.8mm-620.5mm=+0.3mm;

[0174] ΔY=630.3mm-630.0mm=+0.3mm;

[0175] ΔZ=568.7mm-568.5mm=+0.2mm;

[0176] Although the above deviation values ​​are within ±0.5 mm, they do not meet the initial spatial position accuracy (within ±0.1 mm) required by the wiring harness design.

[0177] Determine the maximum allowable bending radius based on the bending performance index of the wire harness material;

[0178] According to the wiring harness material performance parameter technical documents provided by the automotive wiring harness design department (for example, model FLRY-B wiring harness, cross-sectional area 1.0mm 2 ), which specifies the maximum bending radius index of the harness material. The specific maximum bending radius value is 6 times the harness diameter. In this embodiment, the harness material diameter is 8mm, so the maximum allowable bending radius is calculated as: R max =6×8mm=48mm; This bending radius is the maximum allowable radius of the wiring harness material, which is used to ensure that the wiring harness will not be damaged or its performance will be reduced when the space is adjusted. It is a standardized performance indicator in the automotive wiring harness industry.

[0179] Determine the specific spatial area that each connection point can be adjusted with the maximum allowable bending radius as the constraint;

[0180] In this implementation step, the maximum bending radius allowed by the harness material (R max =48mm) as a constraint condition to determine the specific spatial area range within which each connection point can be fine-tuned.

[0181] During the specific implementation process, taking the connection point P2 as an example, a three-dimensional spherical adjustment area with a radius of 48mm is established with the current position coordinates of the connection point (620.8mm, 630.3mm, 568.7mm) as the center; it indicates that the spherical space is the specific allowable area for fine-tuning the position of the connection point P2, that is, the actual position coordinates of the connection point P2 are adjusted within a range of no more than 48mm to avoid damage caused by the bending radius of the wire harness exceeding the allowable limit of the material.

[0182] Furthermore, the specific adjustment area is comprehensively evaluated and determined by the wiring harness design technicians based on the wiring harness material performance indicators and the actual wiring harness assembly space layout.

[0183] In a specific spatial area, fine-tune the position of each connection point one by one to the required position coordinates of the initial relative spatial position relationship;

[0184] In the specific spatial area determined, the connection points are precisely fine-tuned one by one to restore the connection point positions to the position coordinates required by the initial relative spatial position relationship of step S101, and the fine-tuning accuracy is controlled within ±0.05mm.

[0185] During the specific implementation, a six-axis industrial robot (position accuracy ±0.05mm) is used to perform position fine-tuning. Taking connection point P2 as an example, based on the difference between the initial position coordinates in step S101 (620.5mm, 630.0mm, 568.5mm) and the current actual coordinates (620.8mm, 630.3mm, 568.7mm), the specific fine-tuning implementation method is as follows:

[0186] The robot moves 0.3 mm in the negative direction along the X axis;

[0187] The robot moves 0.3 mm in the negative direction along the Y axis;

[0188] The robot moves 0.2mm in the negative direction along the Z axis;

[0189] During the implementation process, the position adjustment is monitored in real time until the actual position coordinates of the connection point are completely consistent with the initial position coordinates.

[0190] After the fine-tuning is completed, the F high-precision laser rangefinder is used again to perform the final measurement and confirmation of the connection point position. The measurement results confirm that the position of the connection point P2 is accurately restored to the initial position coordinates (620.5mm, 630.0mm, 568.5mm), and the measurement accuracy is within ±0.05mm, meeting the requirements of the initial spatial position relationship.

[0191] The other connection points are accurately restored and confirmed one by one according to the above fine-tuning method and steps to ensure that the actual position coordinates of all connection points meet the requirements of the initial relative spatial position relationship of the design.

[0192] S104: After the connection point positions are restored to the initial spatial position relationship, an actual measurement path is determined according to the actual spatial bending shape of each branch segment, and the actual length of each branch segment is measured.

[0193] The purpose of this step is to accurately restore the positions of all connection points to their initial spatial position relationship, determine the precise measurement path based on the specific bending form of the wiring harness in space, and measure the actual length of each wiring harness branch segment to ensure that the automotive wiring harness production and assembly processes meet the design requirements.

[0194] In implementation, determining the actual measurement path based on the actual spatial bending shape of each branch segment and measuring the actual length of each branch segment includes:

[0195] Record the actual spatial bending position of each branch segment;

[0196] In the specific implementation, a high-precision three-dimensional laser scanner (scanning accuracy of ±0.05mm) is used to completely scan the wiring harness after the connection point position correction is completed to obtain accurate three-dimensional point cloud data of the actual bending shape of each wiring harness branch segment in the entire vehicle space.

[0197] Specifically, taking the branch segment T1 (from the connection point P1 to the connection point P2) of the harness as an example, the three-dimensional point cloud data of the actual space bending position obtained by scanning includes the spatial coordinates of several feature position points, for example:

[0198] Spatial position point T1-A (X=800.5mm, Y=400.2mm, Z=700.8mm);

[0199] Spatial position point T1-B (X=950.3mm, Y=500.7mm, Z=730.5mm);

[0200] Spatial position point T1-C (X=1100.6mm, Y=620.1mm, Z=760.2mm);

[0201] Spatial position point T1-D (X=1200.5mm, Y=700.3mm, Z=850.0mm).

[0202] The above position point data are recorded and saved after scanning, with the accuracy controlled within ±0.05mm, and the data volume meets the point cloud density ≥1 point / mm.

[0203] Each branch segment is divided into multiple continuous measurement segments according to the recorded spatial bending positions;

[0204] Based on the actual spatial bending shape data (three-dimensional point cloud data) of the wire harness obtained by scanning in step S104.1, each branch segment is divided into multiple continuous measurement segments to ensure the measurement accuracy and the accuracy of the path determination.

[0205] Specifically, taking the branch segment T1 (connection point P1 to connection point P2) as a specific example, the branch segment is divided into the following multiple continuous measurement segments according to the bending position feature points obtained by scanning:

[0206] Measuring section T1-1: from connection point P1 to position point T1-A;

[0207] Measuring section T1-2: from position point T1-A to position point T1-B;

[0208] Measurement section T1-3: from position point T1-B to position point T1-C;

[0209] Measurement section T1-4: from position point T1-C to position point T1-D;

[0210] Measuring section T1-5: from position point T1-D to connection point P2.

[0211] The measurement segments are selected based on key features such as where the harness bends in space, where the direction changes by more than 20°, and where fixed brackets are located. Each segment is designed to be approximately 200mm to 500mm long, ensuring measurement accuracy within ±0.1mm.

[0212] Determine the actual measurement path for each measurement segment;

[0213] For each measurement segment divided in step S104.2, a precise path fitting is performed using a cubic B-spline curve fitting algorithm using Geomagic ControlX software based on the actual spatial curved point cloud data obtained by scanning to determine the actual measurement path of each measurement segment.

[0214] In a specific implementation, taking the measurement segment T1-1 (P1 to T1-A) as an example, the mathematical expression of the cubic B-spline curve fitted by the spatial coordinate points is:

[0215]

[0216] Where: C(u) is the fitting path curve; P i are control points (the number of control points in this section is 5), namely P1, 3 evenly distributed middle points in the point cloud data, and position point T1-A; N i,3 (u) is the cubic B-spline basis function; the parameter u is the normalized curve parameter, which ranges from [0,1].

[0217] Measure segment by segment and accumulate the actual length of each measuring segment to obtain the actual length of each branch segment;

[0218] According to the determined actual measurement path of each measurement segment, the actual length of each measurement segment is accurately measured segment by segment, and the measured length of each segment is accumulated to obtain the actual length of each wiring harness branch segment; the specific implementation method is disclosed as follows:

[0219] Specifically, taking branch segment T1 as an example, after the paths of each measurement segment (T1-1 to T1-5) have been determined using the cubic B-spline fitting algorithm, the actual length of each segment is calculated segment by segment using numerical integration. The specific formula is as follows:

[0220]

[0221] Where: L 段 is the actual length of each measurement segment; C(u) is the cubic B-spline curve fitted to the path of each measurement segment; the numerical integration calculation uses the Gauss-Legendre numerical integration method, and the integration calculation accuracy is controlled within ±0.05mm;

[0222] Taking the measuring section T1-1 (P1 to T1-A) as a specific example, the actual length measured and calculated is 355.4mm; the actual length of the measuring section T1-2 (T1-A to T1-B) is 260.8mm; the actual length of the measuring section T1-3 (T1-B to T1-C) is 270.2mm; the actual length of the measuring section T1-4 (T1-C to T1-D) is 245.7mm; and the actual length of the measuring section T1-5 (T1-D to P2) is 310.5mm.

[0223] Then the actual lengths of the above-mentioned measurement segments are accurately accumulated to calculate the overall actual length of the branch segment T1:

[0224] Lx1=355.4mm+260.8mm+270.2mm+245.7mm+310.5mm=1442.6mm;

[0225] The calculated result is recorded as the actual length of the harness branch segment T1. The measurement calculation accuracy meets the requirement of ±0.1mm and is clearly stored in a standardized harness quality inspection data table to ensure that the actual harness length measurement result is clear, reproducible and verifiable.

[0226] The above method is used to accurately measure and calculate the actual length of other wiring harness branch segments, and the measured segment lengths are accumulated to ensure that the actual length measurement results of all branch segments are accurate and reliable and meet the actual design and assembly requirements.

[0227] Example 2

[0228] like Figure 2 As shown, the part not described in detail in this embodiment is as shown in Example 1. This embodiment discloses an automatic measurement operation system for automobile wiring harness production inspection, including:

[0229] The measurement preprocessing module 201 is used to place a to-be-tested automotive wiring harness having multiple branch segments and multiple branch connection points on a measurement platform, wherein the measurement platform is pre-set with multiple spatial reference points, measure the initial position coordinates of each branch connection point relative to the spatial reference point without fixing the wiring harness, and determine the initial spatial position relationship of each connection point relative to adjacent connection points based on the initial position coordinates;

[0230] The data correction module 202 is used to determine the local area consisting of the branch connection point and adjacent connection points where the position offset exceeds the allowable range and the initial spatial position relationship of the adjacent connection points is changed, and to sequentially correct the positions of the connection points in the local area according to the wiring harness assembly process sequence to obtain corrected position coordinates.

[0231] The information adjustment module 203 is used to fine-tune the connection point according to the maximum bending radius of the harness material when the corrected position coordinates do not conform to the initial spatial position relationship, so as to restore the connection point position to the initial spatial position relationship;

[0232] The data measurement module 204 is used to determine the actual measurement path according to the actual spatial bending shape of each branch segment after the connection point position is restored to the initial spatial position relationship, and measure the actual length of each branch segment.

[0233] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters, weights and thresholds in the formulas are set by technicians in this field according to actual conditions.

[0234] The above embodiments can be implemented in whole or in part through software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the processes or functions described in accordance with the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired or wireless network. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that contains a collection of one or more available media. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, or a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0235] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. An automatic measurement method for automobile wiring harness production inspection, characterized in that: include: S101: placing a to-be-tested automotive wiring harness having a plurality of branch segments and a plurality of branch connection points on a measurement platform, wherein a plurality of spatial reference points are preset on the measurement platform, and without fixing the wiring harness, measuring the initial position coordinates of each branch connection point relative to the spatial reference point, and determining the initial spatial position relationship of each connection point relative to an adjacent connection point based on the initial position coordinates; S102: When the position offset of the branch connection point exceeds the allowable range and the initial spatial position relationship of adjacent connection points is changed, a local area consisting of the connection point with the position offset and adjacent connection points is determined, and the positions of the connection points in the local area are sequentially corrected according to the wiring harness assembly process sequence to obtain corrected position coordinates; S103: When the corrected position coordinates do not conform to the initial spatial position relationship, fine-tune the connection point according to the maximum bending radius of the harness material to restore the connection point position to the initial spatial position relationship; S104: After the connection point positions are restored to the initial spatial position relationship, an actual measurement path is determined according to the actual spatial bending shape of each branch segment, and the actual length of each branch segment is measured.

2. The automatic measurement method for automobile wiring harness production and testing according to claim 1, characterized in that: Determining the initial spatial position relationship of each connection point relative to adjacent connection points includes: Select three or more non-collinear spatial reference points on the measurement platform as the measurement reference; Measuring the initial spatial distance between each branch connection point and the spatial reference point to obtain a plurality of initial spatial distance values; Calculate the initial three-dimensional position coordinates of each branch connection point according to multiple initial spatial distance values; The initial spatial distance and initial spatial relative angle between each pair of adjacent connection points are calculated and recorded according to the three-dimensional position coordinates of the two adjacent connection points as the initial relative spatial position relationship between the adjacent connection points.

3. The automatic measurement method for automobile wiring harness production and testing according to claim 2, characterized in that: Calculating the initial three-dimensional position coordinates of each branch connection point includes: Determine a spatial coordinate system on the measurement platform using the three or more non-collinear spatial reference points; By measuring the initial spatial distance between each branch connection point and the spatial reference point, the initial distance relationship between the connection point and each spatial reference point in the spatial coordinate system is determined; Calculate the initial coordinate position of each connection point using the initial distance relationship of each connection point relative to the spatial reference point; The calculated initial coordinate position is used as the initial three-dimensional position coordinate of each branch connection point.

4. The automatic measurement method for automobile wiring harness production and testing according to claim 3, characterized in that: The calculation of the initial coordinate position of each connection point includes: Determine the spatial relationship between various spatial reference points based on the spatial coordinate system of the measurement platform; Based on the initial spatial distances from the branch connection points to each spatial reference point, calculate the distance projections of each connection point on each coordinate axis of the spatial coordinate system; The three-dimensional position of each connection point in the spatial coordinate system is determined by using the distance projection of each connection point on each coordinate axis; The determined three-dimensional position is recorded as the initial coordinate position of each connection point.

5. The automatic measurement method for automobile wiring harness production and testing according to claim 4, characterized in that: The obtaining of the corrected position coordinates comprises: Determine the actual position coordinates of the connection point that is offset and each connection point within a local adjustment area formed by a plurality of adjacent connection points; According to the automotive wiring harness assembly process requirements, determine the assembly sequence of each connection point in the local adjustment area in the vehicle assembly; Determine the target position coordinates of each connection point in the local adjustment area in sequence according to the assembly sequence; Compare the differences between the actual position coordinates and the target position coordinates, adjust the position of each connection point one by one according to the assembly sequence until the actual position coordinates of each connection point are the same as the target position coordinates, and output the adjusted actual position coordinates as the corrected position coordinates.

6. The automatic measurement method for automobile wiring harness production and testing according to claim 5, characterized in that: Determining the target position coordinates of each connection point in the local adjustment area includes: Record the actual installation path of the wiring harness during the automobile assembly process and identify the specific vehicle body installation locations involved in the installation path; Determine the specific installation position of each branch connection point within the vehicle body space based on the identified vehicle body installation location; Taking the preset installation reference point in the vehicle body as the reference, measure the three-dimensional spatial coordinates of each connection point relative to the installation reference point; The measured three-dimensional spatial position coordinates are recorded as the target position coordinates of each connection point.

7. The automatic measurement method for automobile wiring harness production and testing according to claim 6, characterized in that: The fine-tuning of the connection point according to the maximum bending radius of the wiring harness material includes: Measure the actual spatial position of each connection point after position correction; Determine the maximum allowable bending radius based on the bending performance index of the wire harness material; Determine the specific spatial area that each connection point can be adjusted with the maximum allowable bending radius as the constraint; In a specific spatial area, fine-tune the position of each connection point one by one to the required position coordinates of the initial relative spatial position relationship.

8. The automatic measurement method for automobile wiring harness production and testing according to claim 7, characterized in that: Determining the actual measurement path based on the actual spatial bending shape of each branch segment and measuring the actual length of each branch segment includes: Record the actual spatial bending position of each branch segment; Each branch segment is divided into multiple continuous measurement segments according to the recorded spatial bending positions; Determine the actual measurement path for each measurement segment; The actual length of each measured segment is measured segment by segment and accumulated to obtain the actual length of each branch segment.

9. An automatic measurement system for automobile wiring harness production testing, implemented based on the automatic measurement method for automobile wiring harness production testing according to any one of claims 1 to 8, characterized in that: include: A measurement preprocessing module is used to place a to-be-tested automotive wiring harness having multiple branch segments and multiple branch connection points on a measurement platform, the measurement platform being pre-set with multiple spatial reference points, and to measure the initial position coordinates of each branch connection point relative to the spatial reference point without fixing the wiring harness, and to determine the initial spatial position relationship of each connection point relative to adjacent connection points based on the initial position coordinates; A data correction module is used to determine the local area consisting of the branch connection point and adjacent connection points where the position offset exceeds the allowable range and the initial spatial position relationship of the adjacent connection points is changed, and to correct the positions of the connection points in the local area in sequence according to the wiring harness assembly process sequence to obtain the corrected position coordinates; An information adjustment module is used to fine-tune the connection point according to the maximum bending radius of the harness material when the correction position coordinates do not conform to the initial spatial position relationship, so as to restore the connection point position to the initial spatial position relationship; The data measurement module is used to determine the actual measurement path and measure the actual length of each branch segment based on the actual spatial bending shape of each branch segment after the connection point position is restored to the initial spatial position relationship.

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