CN-122015676-A - Method, system and storage medium for detecting full circumference of cylindrical structural member based on sensor group

CN122015676ACN 122015676 ACN122015676 ACN 122015676ACN-122015676-A

Abstract

The invention relates to a full-circle detection method, a full-circle detection system and a storage medium of a cylindrical structural member based on a sensor group, wherein the method comprises the following steps of responding to a trigger signal of the cylindrical structural member reaching a preset measurement point to generate a synchronous acquisition instruction and sending the synchronous acquisition instruction to the sensor group, the sensor group comprises at least three 3D line laser sensors annularly arranged on the circumference of the cylindrical structural member, the sensor group is controlled to execute the synchronous acquisition instruction, meanwhile, the sensor group is controlled to move relative to the cylindrical structural member so as to acquire a plurality of groups of three-dimensional point cloud data sets in the moving process, a full-circle three-dimensional point cloud model representing the circumferential surface of the cylindrical structural member is generated according to the plurality of groups of three-dimensional point cloud data sets, and full-circle parameters of the cylindrical structural member are calculated based on the full-circle three-dimensional point cloud model, so that whether the cylindrical structural member is qualified or not is judged according to the full-circle parameters.

Inventors

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Assignees

高视科技(苏州)股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260119

Claims (10)

1. The method for detecting the full circumference of the cylindrical structural member based on the sensor group is characterized by comprising the following steps of: Responding to a trigger signal of a cylindrical structural member reaching a preset measuring point to generate a synchronous acquisition instruction and sending the synchronous acquisition instruction to a sensor group, wherein the sensor group comprises at least three 3D line laser sensors annularly arranged on the circumference of the cylindrical structural member; the sensor group is controlled to execute the synchronous acquisition instruction, and meanwhile, the sensor group and the cylindrical structural member are controlled to move relatively so as to acquire a plurality of groups of three-dimensional point cloud data sets in the moving process; Generating a full-circumference three-dimensional point cloud model representing the circumferential surface of the cylindrical structural member according to the plurality of groups of three-dimensional point cloud data sets; and calculating the full-circumference parameter of the cylindrical structural member based on the full-circumference three-dimensional point cloud model, so as to judge whether the cylindrical structural member is qualified or not according to the full-circumference parameter.
2. The method for detecting the full circumference of a cylindrical structural member based on a sensor group according to claim 1, wherein the full circumference parameters include the diameter and cylindricity of the cylindrical structural member.
3. The method for detecting the full circumference of the cylindrical structural member based on the sensor group according to claim 2, wherein calculating the diameter of the cylindrical structural member comprises the steps of: Sequentially intercepting point cloud data of a plurality of cross sections from the full-circumference three-dimensional point cloud model at a plurality of preset height positions from the bottom of the cylindrical structural member along the axial direction of the cylindrical structural member; Respectively carrying out circular fitting on the point cloud data of each cross section, and calculating to obtain the fitting circle diameter corresponding to each cross section; Carrying out statistical analysis on all the fitted circle diameters to obtain diameter measurement data comprising average value, maximum value, minimum value and standard deviation thereof; And taking the average value of the diameters of the fitting circles as a diameter measurement result of the cylindrical structural member.
4. The method for detecting the full circumference of the cylindrical structural member based on the sensor group according to claim 2, wherein calculating the cylindricity of the cylindrical structural member comprises the following steps: performing cylindrical surface fitting on the full-circumference three-dimensional point cloud model to obtain a reference cylindrical surface; calculating the normal distances from all measurement points in the full-circumference three-dimensional point cloud model to the reference cylindrical surface; determining the maximum value and the minimum value in all the normal distances; and calculating the difference between the maximum value and the minimum value to obtain the cylindricity extremum difference of the cylindrical structural member.
5. The method for measuring the full circumference of a cylindrical structural member of a sensor group according to claim 1, further comprising a system calibration step, before the step of generating the synchronous acquisition command: Fixing the polyhedral calibration block to a preset measuring station; the sensor group is controlled to scan the polyhedral calibration blocks, and a calibration point cloud data set under each sensor coordinate system is obtained; acquiring a coordinate transformation matrix from the sensor coordinate system to the global coordinate system according to the mapping relation between the polyhedral calibration block and the calibration point cloud data set; and establishing preset system calibration parameters according to the coordinate transformation matrix.
6. The method for measuring the full circumference of the cylindrical structural member of the sensor group according to claim 1, further comprising a point cloud filtering step after generating the full circumference three-dimensional point cloud model: and identifying and removing outlier noise points caused by reflection in the whole-body three-dimensional point cloud model by adopting an optical filtering algorithm and a point cloud post-processing algorithm.
7. The method for measuring the full circumference of the cylindrical structural member of the sensor group according to claim 1, wherein the step of generating the synchronous acquisition command in response to the trigger signal of the cylindrical structural member reaching the preset measuring point comprises the following steps: The position of the cylindrical structural member is monitored in real time through a photoelectric sensor arranged at the preset measuring point; When the photoelectric sensor judges that the preset reference position of the cylindrical structural member enters an effective detection area, the trigger signal is generated and transmitted to a main control unit; and responding to the trigger signal and generating the synchronous acquisition instruction based on a preset measurement time sequence.
8. The method for measuring the full circumference of a cylindrical structural member of a sensor group according to claim 1, wherein the generating a full circumference three-dimensional point cloud model characterizing the circumferential surface of the cylindrical structural member comprises the steps of: transforming each group of three-dimensional point cloud data sets to the global coordinate system by utilizing a coordinate transformation matrix in system calibration parameters, and completing initial registration; based on the geometric characteristics of the three-dimensional point cloud data sets in the overlapping area after transformation, adopting an iterative nearest point algorithm to perform accurate registration; Combining the plurality of sets of three-dimensional point cloud data sets after accurate registration into a single and seamless whole-body three-dimensional point cloud model.
9. The utility model provides a cylinder structure full circumference diameter detecting system based on sensor group which characterized in that includes following module: The system comprises a command generation module, a synchronous acquisition module and a sensor group, wherein the command generation module responds to a trigger signal of a cylindrical structural member reaching a preset measuring point to generate a synchronous acquisition command and send the synchronous acquisition command to the sensor group; The data acquisition module is used for controlling the sensor group to execute the synchronous acquisition instruction and simultaneously controlling the sensor group to move relative to the cylindrical structural member so as to acquire a plurality of groups of three-dimensional point cloud data sets in the movement process; The model generation module is used for generating a full-circumference three-dimensional point cloud model representing the circumferential surface of the cylindrical structural member according to the plurality of groups of three-dimensional point cloud data sets; and the detection module is used for calculating the full-circumference parameter of the cylindrical structural member based on the full-circumference three-dimensional point cloud model so as to judge whether the cylindrical structural member is qualified or not according to the full-circumference parameter.
10. A readable storage medium having stored thereon a computer program, wherein the computer program is executed by a processor to perform the sensor group based full circumference detection method of a cylindrical structural member as claimed in any one of claims 1-8.

Description

Method, system and storage medium for detecting full circumference of cylindrical structural member based on sensor group Technical Field The invention relates to the technical field of machine vision and detection of cylindrical structural members, in particular to a method, a system and a storage medium for detecting the full circumference of a cylindrical structural member based on a sensor group. Background With the rapid development of new energy automobiles and energy storage industry, the demand and quality requirements of cylindrical structural members (such as various lithium ion structural members) are increasingly improved. The energy density, the safety performance and the assembly precision in the module of the structure are directly determined by the key process parameters such as the uniformity of the diameter of the shell, the cylindricity and the like, so that the realization of high-speed, high-precision and full-coverage online full-inspection becomes a core link for guaranteeing the product quality and the production efficiency. At present, the prior art mainly relies on the following modes for measuring the outer diameter and cylindricity of a cylindrical structural member, and has obvious limitations, namely, firstly, the method can achieve higher absolute precision by adopting contact measurement, but has low measurement efficiency, and is difficult to meet the beat requirement of a production line. Meanwhile, the measuring force applied by the contact measuring head can cause the thin-wall shell of the structural part to generate tiny deformation, measurement errors are introduced, the equipment cost is high, the operating environment requirement is strict, and the device cannot be integrated in a high-speed assembly line to realize full detection. Secondly, non-contact means such as single-point laser scanning or two-dimensional vision measurement are adopted, and the method can only acquire partial circumferential profile or two-dimensional projection information of a certain axial position of a structural member generally, and cannot synchronously acquire complete circumferential three-dimensional morphology data. This results in that it can only be used for sampling detection, and is extremely prone to missing detection of micro defects such as local depressions, protrusions and the like existing on the surface of the structural member. Meanwhile, based on a limited section or a two-dimensional image, the true cylindricity parameter reflecting the whole shape is difficult to accurately calculate, the measurement dimension is not complete, and the reliability is not enough. Third, a single 3D line laser sensor is used for scanning, and although this method can obtain a three-dimensional point cloud, in order to cover the entire circumference of the cylinder, an additional precise rotating mechanism is usually required to drive a structural member or the sensor itself for rotating scanning. The system complexity and cost are increased, the measurement beat is prolonged due to the introduction of mechanical motion, dynamic errors (such as radial runout and axial float) in the rotation process can directly influence the stability and precision of data acquisition, the reliability of a measurement result is difficult to guarantee, and the application of the system in high-speed online detection is restricted. In addition, although the prior art is directed at the research of 3D line laser measurement of rigid parts such as shafts, the method is mostly applied to a controlled offline detection environment, the system calibration process is complex (for example, accurate modeling and compensation are needed for sensor installation eccentricity and workpiece clamping eccentricity), and the method is difficult to adapt to online measurement scenes of quick model switching in the battery and structural member industries and extremely high requirements on detection beats and stability. The application relates to a method, a system and a storage medium for detecting the whole circumference of a cylindrical structural member based on a sensor group, which are used for solving the problems. Disclosure of Invention To achieve the above and other advantages and in accordance with the purpose of the present invention, a first object of the present invention is to provide a method for detecting a full circumference of a cylindrical structural member based on a sensor group, comprising the steps of: responding to a trigger signal of the cylindrical structural member reaching a preset measuring point to generate a synchronous acquisition instruction and sending the synchronous acquisition instruction to a sensor group; Responding to a trigger signal of a cylindrical structural member reaching a preset measuring point to generate a synchronous acquisition instruction and sending the synchronous acquisition instruction to a sensor group, wherein the sensor group comprises at least three 3D line laser