Method for detecting thickness of vertical section of curved plate

Abstract

The invention provides a curved plate vertical section thickness detection method, and the method employs an XY plane moving mechanism to drive a correlation type dual-laser distance measurement sensor detection unit to move in an XY plane, and carries out the inspection of all positions of a to-be-detected curved plate. In the detection process, the inclination direction of the surface of the plate in the detection advancing direction is judged in real time, and the translation distance of the corresponding laser distance measuring sensor at the current moment and the previous moment is calculated according to the inclination direction; then, according to the translation distance and the Z-axis coordinate variable quantity of the detection point of the laser distance measuring sensor, the inclination angle between the current detection point and the detection point at the previous moment is calculated; and then according to the inclination angle and the currently detected Z-direction thickness value of the sheet, calculating the thickness value of the vertical section of the sheet corresponding to the current detection point of the other laser distance measuring sensor by using a trigonometric function relationship. Through the detection method provided by the invention, the thickness value of the vertical section of each position of the curved plate can be rapidly detected in real time.

Description

Technical Field

[0001] This invention belongs to the field of measurement and testing technology, and specifically relates to a method for detecting the thickness of the vertical cross-section of a curved panel. Background Technology

[0002] Measuring the thickness of curved plates (such as the corrugated plates of plate heat exchangers) is complex. Currently, the main methods used in industrial thickness measurement are contact and non-contact methods. The most widely used contact method is the coordinate measuring machine (CMM). CMMs acquire coordinate data by detecting the contact between the probe and the workpiece. They are suitable for relatively small workpieces, require professional operation, and improper operation can damage the workpiece and lead to difficult-to-overcome measurement errors, while also being slow. Non-contact measurement methods mainly include through-beam laser ranging. This method uses two opposing laser rangefinders to detect the distance between the upper and lower surfaces of the plate. The thickness of the plate is then obtained by subtracting the known installation distance between the two laser rangefinders from the detection distance of the first and second laser rangefinders. This through-beam laser ranging method is suitable for thickness measurement of flat plates, but it cannot achieve continuous effective thickness measurement of curved plates. This is because the actual effective thickness of a curved plate is the thickness of the vertical cross section between its upper and lower surfaces. However, the detection direction of the through-beam laser ranging method is difficult to automatically adapt to the constantly changing curved shape of the plate in real time and remain perpendicular to the curved surface. Therefore, it cannot accurately measure the actual effective thickness of curved plates. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for detecting the thickness of the vertical section of a curved panel.

[0004] This invention is achieved through the following technical solution: A method for detecting the thickness of a curved panel's vertical cross-section, the method being as follows: Step 1: Use the XY plane moving mechanism to drive the through-beam dual laser rangefinder sensor detection unit to move in the XY plane to inspect each position of the curved panel to be inspected; during the inspection process, record the detection point coordinates of the first laser rangefinder sensor and the second laser rangefinder sensor according to the sampling interval. Step 2: During the detection process, the tilt direction of the plate surface along the detection travel direction is determined by the change of the Z-axis coordinate of the detection point at the current moment and the previous moment using any laser rangefinder sensor. Step 3: When it is determined that the surface of the plate is tilted upwards along the detection travel direction, calculate the translational distance S1 of the first laser rangefinder sensor in the XY plane between the current moment and the previous moment; then, based on the calculated S1 and the change in the Z-axis coordinate of the detection point of the first laser rangefinder sensor between the current moment and the previous moment. Calculate the tilt angle α1 between the current detection point and the previous detection point on the upper surface of the plate; then, based on the calculated tilt angle α1 and the Z-axis thickness value of the plate detected at the current moment... The thickness h of the vertical section of the plate corresponding to the current detection point of the second laser rangefinder is calculated using trigonometric functions. tc ; Step 4: When it is determined that the surface of the plate is tilted downwards along the detection travel direction, calculate the translation distance S2 in the XY plane between the current time and the previous time of the second laser rangefinder; then, based on the calculated S2 and the change in the Z-axis coordinate of the detection point between the current time and the previous time of the second laser rangefinder... Calculate the tilt angle α2 between the current detection point and the previous detection point on the lower surface of the plate; then, based on the calculated tilt angle α2 and the Z-axis thickness value of the plate detected at the current moment... The thickness h of the vertical section of the plate corresponding to the current detection point of the first laser rangefinder is calculated using trigonometric functions. tc .

[0005] In the above technical solution, the through-beam dual laser rangefinder detection unit includes a first laser rangefinder and a second laser rangefinder mounted symmetrically on a C-shaped frame. The curved panel to be detected is located between the first laser rangefinder and the second laser rangefinder. The first laser rangefinder detects the distance from the upper surface of the panel, and the second laser rangefinder detects the distance from the lower surface of the panel.

[0006] In the above technical solution, the XY plane moving mechanism includes a transverse linear electric slide and a longitudinal linear electric slide. The longitudinal linear electric slide is installed on the transverse linear electric slide and is driven by the transverse linear electric slide to move along the X-axis. The through-beam dual laser rangefinder detection unit is installed on the longitudinal linear electric slide and is driven by the longitudinal linear electric slide to move along the Y-axis.

[0007] In the above technical solution, in step 2, if the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is negative, it is determined that the plate is tilted upward along the detection direction; if the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is positive, it is determined that the plate is tilted downward along the detection direction; if the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is 0, it is determined that the plate is not tilted along the detection direction.

[0008] In the above technical solution, in step 2, if the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is positive, it is determined that the plate is tilted upward along the detection direction; if the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is negative, it is determined that the plate is tilted downward along the detection direction; if the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is 0, it is determined that the plate is not tilted along the detection direction.

[0009] In the above technical solutions, ,in, It is the X-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the first laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the previous moment.

[0010] In the above technical solutions, , ;in, This represents the distance value detected by the first laser rangefinder at the current moment to the upper surface of the distance plate. This is the distance value detected by the first laser rangefinder on the upper surface of the distance plate at the previous moment.

[0011] In the above technical solutions, ,in, It is the X-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the second laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the second laser ranging sensor at the previous moment.

[0012] In the above technical solutions, ,in, This represents the distance value detected by the second laser rangefinder to the lower surface of the distance plate at the current moment. This is the distance value detected by the second laser rangefinder on the lower surface of the distance plate at the previous moment.

[0013] In the above technical solution, in step 3, In step 4, .

[0014] In the above technical solutions, ,in, The installation distance between the first laser rangefinder and the second laser rangefinder; It refers to the Z-axis coordinate of the current detection point on the upper surface of the plate, which is equal to the distance value of the upper surface of the plate currently detected by the first laser rangefinder. It refers to the Z-axis coordinate of the current detection point on the lower surface of the plate, which is equal to the distance value of the lower surface of the plate currently detected by the second laser rangefinder.

[0015] The advantages and beneficial effects of this invention are as follows: This invention utilizes an XY-plane moving mechanism to drive a through-beam dual-laser rangefinder sensor detection unit to move in the XY-plane, performing inspections at various locations on the curved panel to be inspected. The detection method of this invention enables real-time and rapid online detection of the vertical cross-sectional thickness value at various locations on the curved panel. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the formal structure of the detection unit of the through-beam dual-laser rangefinder sensor.

[0017] Figure 2 This is a side view of the detection unit of the through-beam dual-laser rangefinder sensor.

[0018] Figure 3 This is a schematic diagram illustrating the principle of calculating the vertical section thickness when the plate is tilted upwards along the detection direction.

[0019] Figure 4 This is a schematic diagram illustrating the principle of calculating the vertical section thickness when the plate is tilted downwards along the detection direction.

[0020] Figure 5 This is a test result image of a curved panel.

[0021] Figure 6 This is a flowchart of the detection method of the present invention.

[0022] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0024] This embodiment provides a method for detecting the thickness of the vertical section of a curved panel. See Appendix. Figure 6 The detection method is as follows: Step 1: Use the XY plane moving mechanism to drive the through-beam dual laser rangefinder sensor detection unit to move in the XY plane to inspect each position of the curved panel to be inspected.

[0025] For details, please see the appendix. Figure 1 and attached Figure 2 The through-beam dual laser rangefinder detection unit includes a first laser rangefinder 21 and a second laser rangefinder 22 symmetrically arranged on a C-shaped frame 1. The curved panel 3 to be detected is located between the first laser rangefinder 11 and the second laser rangefinder 12. The first laser rangefinder 11 detects the distance from the upper surface of the panel, and the second laser rangefinder 12 detects the distance from the lower surface of the panel.

[0026] During the inspection, the coordinates (x, y, y) of the detection points of the first laser ranging sensor 11 are recorded according to the sampling interval. 1t y 1t z 1t ) and the detection point coordinates (x) of the second laser ranging sensor 12 2t y 2t z 2t ), where z 1t This refers to the Z-axis coordinate of the detection point on the upper surface of the plate, which is equal to the distance value detected by the first laser rangefinder 11 from the upper surface of the plate; z 2t It refers to the Z-axis coordinate of the detection point on the lower surface of the plate, which is equal to the distance value detected by the second laser rangefinder 12 from the lower surface of the plate.

[0027] Furthermore, the XY plane moving mechanism typically includes a transverse linear electric slide and a longitudinal linear electric slide. The longitudinal linear electric slide is mounted on the transverse linear electric slide and is driven by the transverse linear electric slide to move along the X-axis. The through-beam dual-laser rangefinder detection unit is mounted on the longitudinal linear electric slide and is driven by the longitudinal linear electric slide to move along the Y-axis, thereby realizing the movement of the through-beam dual-laser rangefinder detection unit in the XY plane.

[0028] Step 2: During the detection process, the tilt direction of the plate surface along the detection travel direction is determined in real time (the detection travel direction refers to the direction in which the laser rangefinder sensor moves). The specific determination method is: to judge by the change of the Z-axis coordinate of the detection point of the laser rangefinder sensor at the current moment and the previous moment (here, the previous moment refers to the moment n sampling intervals before the current moment): if the change of the Z-axis coordinate of the detection point of the first laser rangefinder sensor at the current moment and the previous moment is negative, it indicates that the plate is tilted upward along the detection travel direction (see Appendix). Figure 3 If the change in the Z-axis coordinate of the detection point at the current moment and the previous moment of the first laser ranging sensor is positive, it indicates that the plate is tilted downwards along the detection travel direction (see Appendix). Figure 4 If the change in the Z-axis coordinate of the detection point at the current moment and the previous moment of the first laser rangefinder is 0, it indicates that the plate is not tilted along the detection direction, i.e., it is parallel. Alternatively, it can be determined using the detection data from the second laser rangefinder. If the change in the Z-axis coordinate of the detection point at the current moment and the previous moment of the second laser rangefinder is positive, it indicates that the plate is tilted upwards along the detection direction (see Appendix). Figure 3 If the change in the Z-axis coordinate of the detection point at the current moment and the previous moment of the second laser ranging sensor is negative, it indicates that the plate is tilted downwards along the detection travel direction (see Appendix). Figure 4 If the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current moment and the previous moment is 0, it means that the plate is not tilted along the detection direction, that is, it is parallel.

[0029] Step 3: When it is determined that the surface of the plate is tilted upwards along the detection travel direction, see Appendix. Figure 3 Calculate the translational distance S of the first laser rangefinder sensor in the XY plane between the current moment and the previous moment. 1； ; in, It is the X-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the first laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the previous moment.

[0030] Then, based on the calculated S1 and the change in the Z-axis coordinate of the detection point at the current and previous moments of the first laser ranging sensor... Calculate the tilt angle α between the current detection point and the previous detection point on the upper surface of the plate. 1； ; ; This represents the distance value detected by the first laser rangefinder at the current moment to the upper surface of the distance plate. This is the distance value detected by the first laser rangefinder on the upper surface of the distance plate at the previous moment.

[0031] Then, based on the calculated tilt angle a1, the thickness h of the vertical section of the plate corresponding to the current detection point of the second laser rangefinder is calculated. tc； ; h t The Z-axis thickness value of the plate detected by the first laser rangefinder and the second laser rangefinder at the current moment; ; The installation distance between the first laser rangefinder and the second laser rangefinder is fixed and known.

[0032] Step 4: When it is determined that the surface of the plate is tilted downwards along the detection travel direction, see Appendix. Figure 4 Calculate the translational distance S of the second laser ranging sensor in the XY plane between the current time and the previous time. 2； ; in, It is the X-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the second laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the second laser rangefinder at the previous moment.

[0033] Then, based on the calculated S2 and the change in the Z-axis coordinate of the detection point at the current and previous moments of the second laser ranging sensor... Calculate the tilt angle α between the current detection point and the previous detection point on the lower surface of the plate. 2； ; ; This represents the distance value detected by the second laser rangefinder to the lower surface of the distance plate at the current moment. This is the distance value detected by the second laser rangefinder on the lower surface of the distance plate at the previous moment.

[0034] Then, based on the calculated tilt angle a2, the thickness h of the vertical section of the plate corresponding to the current detection point of the first laser rangefinder is calculated. tc； ; h t The Z-axis thickness value of the plate detected by the first laser rangefinder and the second laser rangefinder at the current moment; ; The installation distance between the first laser rangefinder and the second laser rangefinder is fixed and known.

[0035] Furthermore, it should be noted that when it is determined that the plate is not tilted along the detection direction, either step 3 or step 4 can be selected for calculation. That is, since there is no tilt, the tilt angle a1 in step 3 is 0, and the tilt angle a2 in step 4 is 0. Therefore, the final calculated... In other words, when it is determined that the plate is not tilted along the detection direction, the Z-axis thickness h of the plate detected by the first and second laser rangefinders at the current moment is... t That is, the currently effective vertical section thickness value h. tc .

[0036] See appendix Figure 5 This is a detection result image of a curved panel sheet. It can quickly and in real time detect the vertical cross-sectional thickness value h at various positions of the curved panel sheet according to the sampling interval. tc .in, Figure 5 In the diagram, point 01 on the lower surface of the curved panel and point 02 on the upper surface of the curved panel both represent the starting points for the vertical section thickness. The XY coordinates of these starting points are recorded, thus allowing us to determine the vertical section thickness value corresponding to a specific detection point on the curved panel. It should be noted that... Figure 5 This is for illustrative purposes only. In actual testing, the spacing between the starting points is very close, preferably 1mm.

[0037] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0038] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0039] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method for detecting the thickness of a curved panel's vertical cross-section, characterized in that: Includes the following steps: Step 1: Use the XY plane moving mechanism to drive the through-beam dual laser rangefinder sensor detection unit to move in the XY plane to inspect each position of the curved panel to be inspected; during the inspection process, record the detection point coordinates of the first laser rangefinder sensor and the second laser rangefinder sensor according to the sampling interval. Step 2: During the detection process, the tilt direction of the plate surface along the detection travel direction is determined by the change of the Z-axis coordinate of the detection point at the current moment and the previous moment using any laser rangefinder sensor. Step 3: When it is determined that the surface of the plate is tilted upwards along the detection travel direction, calculate the translational distance S1 of the first laser rangefinder sensor in the XY plane between the current moment and the previous moment; then, based on the calculated S1 and the change in the Z-axis coordinate of the detection point of the first laser rangefinder sensor between the current moment and the previous moment. Calculate the tilt angle α1 between the current detection point and the previous detection point on the upper surface of the plate; then, based on the calculated tilt angle α1 and the Z-axis thickness value of the plate detected at the current moment... The thickness h of the vertical section of the plate corresponding to the current detection point of the second laser rangefinder is calculated using trigonometric functions. tc ; Step 4: When it is determined that the surface of the plate is tilted downwards along the detection travel direction, calculate the translation distance S2 in the XY plane between the current time and the previous time of the second laser rangefinder; then, based on the calculated S2 and the change in the Z-axis coordinate of the detection point between the current time and the previous time of the second laser rangefinder... Calculate the tilt angle α2 between the current detection point and the previous detection point on the lower surface of the plate; then, based on the calculated tilt angle α2 and the Z-axis thickness value of the plate detected at the current moment... The thickness h of the vertical section of the plate corresponding to the current detection point of the first laser rangefinder is calculated using trigonometric functions. tc .

2. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: The through-beam dual laser rangefinder detection unit includes a first laser rangefinder and a second laser rangefinder mounted symmetrically on a C-shaped frame. The curved panel to be detected is located between the first laser rangefinder and the second laser rangefinder. The first laser rangefinder detects the distance from the upper surface of the panel, and the second laser rangefinder detects the distance from the lower surface of the panel.

3. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: In step 2, if the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is negative, it is determined that the plate is tilted upward along the detection direction. If the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is positive, it is determined that the plate is tilted downward along the detection direction. If the change in the Z-axis coordinate of the detection point of the first laser ranging sensor at the current time and the previous time is 0, it is determined that the plate is not tilted along the detection direction.

4. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: In step 2, if the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is positive, it is determined that the plate is tilted upward along the detection direction. If the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is negative, it is determined that the plate is tilted downward along the detection direction. If the change in the Z-axis coordinate of the detection point of the second laser ranging sensor at the current time and the previous time is 0, it is determined that the plate is not tilted along the detection direction.

5. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: ,in, It is the X-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the first laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the first laser rangefinder at the previous moment.

6. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: , ;in, This represents the distance value detected by the first laser rangefinder at the current moment to the upper surface of the distance plate. This is the distance value detected by the first laser rangefinder on the upper surface of the distance plate at the previous moment.

7. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: ,in, It is the X-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the X-axis coordinate of the detection point of the second laser rangefinder at the previous moment. It is the Y-axis coordinate of the detection point of the second laser rangefinder at the current moment. It is the Y-axis coordinate of the detection point of the second laser rangefinder at the previous moment.

8. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: ,in, This represents the distance value detected by the second laser rangefinder to the lower surface of the distance plate at the current moment. This is the distance value detected by the second laser rangefinder on the lower surface of the distance plate at the previous moment.

9. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: In step 3, In step 4, .

10. The method for detecting the thickness of a curved panel's vertical cross-section according to claim 1, characterized in that: ,in, The installation distance between the first laser rangefinder and the second laser rangefinder is the value. It refers to the Z-axis coordinate of the current detection point on the upper surface of the plate, which is equal to the distance value of the upper surface of the plate currently detected by the first laser rangefinder. It refers to the Z-axis coordinate of the current detection point on the lower surface of the plate, which is equal to the distance value of the lower surface of the plate currently detected by the second laser rangefinder.

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