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CN-122015697-A - Three-dimensional detection method and device using multi-point laser ranging

CN122015697ACN 122015697 ACN122015697 ACN 122015697ACN-122015697-A

Abstract

The invention relates to the technical field of three-dimensional detection, in particular to a three-dimensional detection method and a device thereof by utilizing multi-point laser ranging, wherein a detection body with a plurality of detection layers which gradually change according to a certain distance is fixed on an object to be detected, the detection surface is in a sphere, an ellipse or a cone shape and has the characteristic of gradually changing according to a certain distance, a laser ranging device is arranged at the corresponding position of the detection surface according to a certain distance, a multi-point measurement light spot respectively detects the distance data of each point of the detection surface, the distance values of each point generate a unique position ID according to the arrangement sequence, the fixed geometric space relation of each detection point is combined, the three-dimensional coordinates of the object to be detected are calculated, the three-dimensional displacement vector is calculated by comparing with the initial coordinates, and the corresponding device comprises a detection part, a laser ranging part and a processing part. The invention combines the multi-layer detection structure with the laser ranging device, supports two ranging modes of single-point scanning and multi-point synchronization, and has simple structure, convenient deployment and strong adaptability.

Inventors

  • Cai haian

Assignees

  • 浙江中产科技有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. The three-dimensional detection method using the multi-point laser ranging is characterized by comprising the following steps of: The detection surface of the detection body is in a sphere, ellipse or cone shape and has the characteristic of gradual change of graduation according to a certain distance, the detection body is composed of a plurality of detection layers with different heights, and the characteristic of gradual change of graduation according to a certain distance is arranged between each two groups of detection layers; A laser range finder is arranged at a plurality of points according to a certain position relation, so that the laser range finder is fixed on a reference position independent of an object to be detected, and a plurality of measuring light spots emitted by the laser range finder can cover a plurality of detection points on the detection body respectively; the distance data of each point are detected by the plurality of measuring light spots through the laser range finder; calculating and generating characteristic information for uniquely characterizing the position state of the detection body in a preset direction as a position ID according to a plurality of first distance data and a known fixed geometric space relation among a plurality of detection points; based on the position ID and a spatial position relation model between the laser range finder and a detection body, which is established through calibration, calculating three-dimensional space coordinates of the detection body relative to the laser range finder, wherein the three-dimensional space coordinates comprise a Z-axis component corresponding to the height direction and X-axis and Y-axis horizontal components orthogonal to the Z-axis; Recording an initial position ID and an initial three-dimensional coordinate when the detection body is in an initial state; In the subsequent detection, the current position ID and the current three-dimensional coordinate are obtained, compared with the initial position ID and the initial three-dimensional coordinate, and displacement vectors of the object to be detected in the X axis, the Y axis and the Z axis are obtained through calculation.
  2. 2. The method of claim 1, wherein the step of calculating the generated position ID based on the first distance data and the known fixed geometric relationship between the first distance data comprises calculating a combination of differences between the first distance data, the combination of differences constituting the position ID.
  3. 3. The three-dimensional detection method using multi-point laser ranging as set forth in claim 1, wherein the laser ranging device is a single-point laser ranging sensor integrated scanning mechanism; the step of acquiring the plurality of first distance data comprises the steps of controlling the scanning mechanism to drive the laser beams to sequentially scan according to time sequence and measuring the distance between each detection point.
  4. 4. The method for three-dimensional inspection using multi-point laser ranging as set forth in claim 1, wherein the laser ranging device is a synchronous laser ranging sensor having a plurality of independent ranging channels; The step of acquiring the plurality of first distance data comprises the step of synchronously measuring the distance to the corresponding detection point through each ranging channel.
  5. 5. The method of three-dimensional inspection using multi-point laser ranging as set forth in claim 1, wherein the inspection body is an integrally formed rigid member having a spherical, elliptical or tapered shape, and the inspection points on the surface are inspection points having different depths, different inclinations or different heights formed by machining.
  6. 6. The method for three-dimensional inspection using multi-point laser ranging as set forth in claim 5, wherein the inspection body is detachably fixed to the object to be inspected by a magnetic structure, an adhesive layer or a mechanical jig provided on the back surface thereof.
  7. 7. The three-dimensional inspection method using multi-point laser ranging according to claim 1, wherein the spatial position relationship model is established by the following calibration steps: controlling the detector to be at a plurality of different known positions relative to the laser rangefinder; Acquiring corresponding multiple groups of first distance data at each position; And establishing the model through a parameter fitting algorithm based on a plurality of groups of distance data, known position coordinates and fixed geometric relations of detection points.
  8. 8. The three-dimensional inspection method using multi-point laser ranging as set forth in claim 1, further comprising a data verification step of comparing the relative spatial relationship between inspection points calculated from the current distance data with the known fixed geometric relationship; if the deviation exceeds the allowable range, judging that the data is invalid or interference exists.
  9. 9. A three-dimensional inspection apparatus that implements the three-dimensional inspection method according to any one of claims 1 to 8, comprising: The detection point piece is fixed on an object to be detected, the detection point piece is provided with a surface consisting of a plurality of detection layers with different heights, the detection layers are provided with characteristics of gradual change in graduation according to a certain distance, and each group of detection layers comprises a plurality of detection points; A multi-point laser ranging component, which is arranged on an independent reference position and is provided with a plurality of ranging channels, so that each measuring light spot can cover each detecting point on the detecting point component; the processing component is in communication connection with the multi-point laser ranging component and receives distance data from each channel; generating a position ID according to the known fixed geometric relationship between the distance data and the detection points; based on the position ID and a pre-stored spatial position relation model, resolving the three-dimensional coordinates of the detection point piece; And calculating and outputting a displacement vector by comparing the current three-dimensional coordinate with the initial three-dimensional coordinate.
  10. 10. The three-dimensional detecting device according to claim 9, wherein the processing means is integrated in a control unit of the laser ranging means or is an external independent computing device connected to the laser ranging means by wired or wireless communication.

Description

Three-dimensional detection method and device using multi-point laser ranging Technical Field The invention relates to the technical field of three-dimensional detection, in particular to a three-dimensional detection method and a device thereof by utilizing multi-point laser ranging. Background In the fields of machining, precise assembly, structural health monitoring (such as bridge and building deformation detection), automatic control, robot positioning and the like, accurate, real-time and non-contact detection of the position, displacement or posture of an object in a three-dimensional space is a critical core requirement. Currently, the prior art means for implementing three-dimensional detection mainly include the following categories: Contact measurements such as three Coordinate Measuring Machines (CMMs), dial gauges, and the like. The technology has the advantages of high measurement precision by directly contacting the surface of the measured object through the physical probe, but has the defects of complex deployment, stable measurement environment and professional operators, low measurement speed, incapability of meeting the requirements of dynamic or on-line detection, contact measurement, possibility of scratching a soft surface or generating errors caused by measuring force, huge system volume, high cost, difficulty in flexible deployment in industrial sites and incapability of realizing on-line automatic detection. Visual measurement systems such as three-dimensional reconstruction based on monocular, binocular or multi-view cameras, photogrammetry, etc. The technology solves the three-dimensional information of an object by analyzing a shot image or video sequence, has the advantages of non-contact and rich information, but has the following problems and disadvantages of poor environmental adaptability, sensitivity to environmental illumination change, serious performance reduction under the conditions of dim light, strong light or uneven illumination, easy shielding interference, failure in measurement once target characteristic points are shielded, complex calculation, high requirement on hardware calculation force for real-time processing of high-definition image data, large system delay, complicated calibration process, multi-step calibration flow, insufficient convenience in deployment and maintenance, and incapacity of realizing three-dimensional detection by the camera, generally only one-dimensional depth of field can be completed, and three directions need to be detected to realize three-dimensional detection. The multi-sensor discrete combination measurement is that, for example, three single-axis laser displacement sensors are respectively used for measuring the displacement of an object in X, Y, Z three directions, and non-contact measurement is realized to a certain extent, but the system has the main defects that the system is complex, a plurality of independent sensors are required to be accurately installed and calibrated, the measurement axes of the sensors are ensured to be strictly orthogonal and meet at a measured point, the deployment difficulty is high, the cost is high, the total cost is increased due to the fact that the plurality of sensors and the matched installation and adjustment mechanism are used, the data lack of internal association verification, the measurement data in the three directions are mutually independent, the error data generated by the fact that a single sensor is temporarily blocked or interfered by foreign matters cannot be effectively identified and filtered, the anti-interference capability is weak, the false alarm risk is high, the space is limited, and many scenes do not have detection spaces in 3 directions. There is a need for a three-dimensional inspection method and apparatus using multi-point laser ranging that ameliorates the above-described problems. Disclosure of Invention The invention aims to provide a three-dimensional detection method and a device thereof by utilizing multi-point laser ranging so as to solve the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: A three-dimensional detection method using multi-point laser ranging includes the following steps: The detection body is fixed on an object to be detected, the detection surface of the detection body is in a sphere, ellipse or cone shape and has the characteristic of gradual change in graduation according to a certain distance, the detection body consists of a plurality of detection layers with different heights, and the characteristic of gradual change in graduation according to a certain distance is arranged between each two groups of detection layers. The laser distance measuring device is arranged at multiple points according to a certain position relationship, so that the laser distance measuring device is fixed on a reference position independent of an object to be measur