Vibration error elimination method for laser ranging device

Abstract

The invention discloses a method for eliminating vibration errors of a laser distance measuring device, which is used in cooperation with a linear laser measuring device, a reference block is arranged beside a measured element, the reference block has high-precision planeness, and the reference block and the measured element are placed on the same platform. The measured element and the reference block are both in a scanning range of the line laser measuring device, height values of the reference block and a to-be-detected object are obtained at the same time during each scanning, then an average value of the height values of each row of the reference block is obtained row by row and recorded as a height average value of each row, the height average values of each row are averaged to obtain a total height average value, and the total height average value is calculated to obtain a total height average value; and subtracting the height average value of each row of the reference block from the total height average value to obtain a difference value array as a compensation array, and uniformly adding the obtained height values of the corresponding rows of the object to be detected by using the compensation array to perform compensation correction, thereby eliminating a measurement error caused by vibration.

Description

Technical field

[0001] The present invention relates to the field of measurement technology, and in particular to a method for eliminating vibration errors of a laser ranging device. [Background Technology]

[0002] In the industrial field, line laser or point laser ranging devices are widely used in defect detection and automated production. These devices typically use triangulation to determine the distance between the measured object and the ranging device. Data processing then calculates the object's outline dimensions, enabling defect detection or automated production control. However, in actual production processes, vibrations in the production environment can cause errors in the measurements obtained by these devices. Therefore, eliminating these vibration errors is a technical problem that needs to be addressed in the industry. [Summary of the invention]

[0003] The object of the present invention is to provide a method for eliminating vibration errors of a laser ranging device, so as to solve the problem in the prior art that errors exist in the measurement values ​​obtained by the laser ranging device due to environmental vibrations.

[0004] To achieve the above-mentioned object, the present invention is implemented in conjunction with a linear laser measuring device for eliminating vibration errors in a laser ranging device. A reference block is provided next to the measured component. The reference block has a relatively high degree of flatness and is placed on the same platform as the measured component. Both the measured component and the reference block are within the scanning range of the linear laser measuring device. The laser ranging device vibration error elimination method comprises the following steps:

[0005] Step 1: During each scan, the height values ​​of the reference block and the object to be detected are simultaneously obtained;

[0006] Step 2: During each scan, the height values ​​of the reference block and the object to be detected are obtained simultaneously. Then, the average value of the height values ​​of each row of the reference block is obtained row by row, recorded as the average height value of each row. The average height value of each row is then averaged to obtain the total height average value. Then, the average height value of each row of the reference block is subtracted from the total height average value to obtain a difference array as the compensation array;

[0007] Step 3: Use the compensation array to uniformly add the corresponding row height values ​​of the object to be detected to perform compensation correction.

[0008] According to the above main features, in step 2, by selecting the middle area of ​​the reference block as the region of interest, the compensation array is established using the region of interest of the reference block.

[0009] To achieve the above-mentioned objectives, the present invention provides a method for eliminating vibration errors in a laser ranging device in conjunction with a point laser measuring device. A reference block is provided next to the measured component. The reference block has a relatively high degree of flatness and is placed on the same platform as the measured component. The point laser measuring device includes a first point laser measuring device corresponding to the measured component and a second point laser measuring device corresponding to the reference block. The method includes the following steps:

[0010] Step 1: Using the first and second point laser measuring devices to simultaneously obtain the height values ​​of the object to be detected and the reference block;

[0011] Step 2: After the detection is completed, obtain multiple height values ​​of the reference block and obtain their average value as the reference block average value, and subtract the average value from the multiple reference block height values ​​to obtain a difference array as the compensation array;

[0012] Step 3: Use the compensation array to perform corresponding point correction on the height value of the object to be detected each time.

[0013] According to the above main features, the first point laser measuring device includes a plurality of sub-point laser measuring devices to correspond to different positions of the object to be detected.

[0014] According to the above main features, the second point laser measuring device includes a plurality of sub-point laser measuring devices corresponding to different positions of the reference block.

[0015] Compared with the prior art, the present invention utilizes a reference block placed on the same platform as the object to be detected to obtain a compensation array for compensating for the effects of vibration, thereby correcting the measurement values ​​obtained by the laser measuring device and eliminating measurement errors caused by vibration.

Brief Description of the Drawings

[0016] Figure 1 The figure is a schematic diagram of the hardware structure for implementing the vibration error elimination method of the laser ranging device of the present invention.

[0017] Figure 2 Schematic diagram of a method for obtaining a compensation array in a 3D weld defect detection method according to the present invention.

[0018] Figure 3 The present invention is a flow chart of a method for eliminating vibration errors in a laser ranging device.

[0019] Figure 4 Schematic diagram of the hardware structure of the second embodiment of the method for eliminating vibration errors of a laser ranging device according to the present invention.

[0020] Figure 51 is a flow chart of a second embodiment of a method for eliminating vibration errors in a laser ranging device according to the present invention. [Specific implementation method]

[0021] See also Figure 1 Figure 2 shows a hardware schematic diagram of a method for eliminating vibration errors in a laser distance measuring device according to the present invention. The method for eliminating vibration errors in a laser distance measuring device according to the present invention is used in conjunction with a linear laser measuring device 1. A reference block 21 is positioned adjacent to a measured component 22. The reference block 21 has a high degree of flatness and is placed on the same platform 2 as the measured component 22. Both the measured component 22 and the reference block 21 are within the scanning range 110 of the linear laser measuring device 1. Generally, in the scanning direction, the reference block 21 is longer than the measured component 22. The linear laser measuring device 1 comprises a linear laser emitter 11 and an image acquisition element 12. The structure and operating principle of the linear laser measuring device 1 are conventional and will not be described in detail here.

[0022] See also Figure 2 The figure is a schematic diagram of the compensation array acquisition method in the 3D weld defect detection method of the present invention. In actual implementation, the average value of the height value of each row of the reference block is obtained row by row using a line scanning laser ranging device, which is recorded as the average height value of each row H1, forming the following Figure 2 The formation of Figure 2 The measured value curve in the figure is then averaged to obtain the total height average H0 (i.e. Figure 2 Then, the total height average value H0 is subtracted from the average height value H1 of each row of the reference block to obtain a difference array as a compensation array, such as Figure 2 The average height H1 of the reference block corresponding to the Nth scan line and the average total height H0 are calculated. The difference between the two is the difference corresponding to the Nth scan line. Thus, a compensation difference value for each row is established to form a compensation array. Of course, in actual implementation, this does not necessarily have to be based on each scan line; the difference value corresponding to each time interval can also be obtained in a time-series manner to establish a compensation array.

[0023] See also Figure 3 FIG. 1 is a flow chart of a method for eliminating vibration errors in a laser ranging device according to the present invention. The method for eliminating vibration errors in a laser ranging device according to the present invention comprises the following steps:

[0024] Step 1: During each scan, the height values ​​of the reference block and the object to be detected are simultaneously obtained;

[0025] Step 2: During each scan, the height values ​​of the reference block and the object to be detected are obtained simultaneously. Then, the average value of the height values ​​of each row of the reference block is obtained row by row, recorded as the average height value of each row. The average height value of each row is then averaged to obtain the total height average value. Then, the average height value of each row of the reference block is subtracted from the total height average value to obtain a difference array as the compensation array;

[0026] Step 3: Use the compensation array to uniformly add the corresponding row height values ​​of the object to be detected to perform compensation correction.

[0027] In a specific implementation, in step 2, the compensation array is established using the region of interest (ROI) of the reference block by selecting the middle region of the reference block as the ROI. The ROI can be a partial region symmetrically located on either side of the axis of the reference block. This eliminates the need to process image data for the entire reference block; only the data for the ROI is processed, thereby reducing the amount of data processing.

[0028] See also Figure 4 Figure 2 shows a hardware schematic diagram of a second embodiment of the present invention's method for eliminating vibration errors in a laser ranging device. In this embodiment, the present invention's method for eliminating vibration errors in a laser ranging device is used in conjunction with a point laser measuring device. A reference block 42 is positioned adjacent to a measured element 41. This reference block 42 has a high degree of flatness and is placed on the same platform 5 as the measured element 41. The point laser measuring device includes a first point laser measuring device 31 corresponding to the measured element 41 and a second point laser measuring device 32 corresponding to the reference block 42.

[0029] See also Figure 5 FIG. 2 is a flow chart of a second embodiment of a method for eliminating vibration errors in a laser ranging device according to the present invention. The method for eliminating vibration errors in a laser ranging device according to the present invention comprises the following steps:

[0030] Step 1: Using the first and second point laser measuring devices to simultaneously obtain the height values ​​of the object to be detected and the reference block;

[0031] Step 2: After the detection is completed, obtain multiple height values ​​of the reference block and obtain their average value, and subtract the multiple reference block height values ​​from the average value to obtain a difference array as a compensation array;

[0032] Step 3: Use the compensation array to perform corresponding point correction on the height value of the object to be detected each time.

[0033] In a specific implementation, the first point laser measuring device includes multiple sub-point laser measuring devices corresponding to different locations on the object to be inspected. The height values ​​measured by these multiple sub-point laser measuring devices are also corrected using the compensation array obtained in step 2. Similarly, the second point laser measuring device includes multiple sub-point laser measuring devices. Similarly, similar to the first embodiment, the measurement values ​​of the multiple sub-point laser measuring devices of the first and second point laser measuring devices are obtained and averaged. This average is then used as the basis for calculation, thereby further improving measurement accuracy.

[0034] Compared with the prior art, the present invention utilizes a reference block placed on the same platform as the object to be detected to obtain a compensation array for compensating for the effects of vibration, thereby correcting the measurement values ​​obtained by the laser measuring device and eliminating measurement errors caused by vibration.

[0035] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for eliminating vibration errors in a laser distance measuring device, used in conjunction with a linear laser measuring device, wherein a reference block is provided next to the measured component, the reference block having a high degree of flatness and placed on the same platform as the measured component, the measured component and the reference block being within the scanning range of the linear laser measuring device, characterized in that The laser distance measuring device vibration error elimination method comprises the following steps: Step 1: During each scan, the height values ​​of the reference block and the object to be detected are simultaneously obtained; Step 2: During each scan, the height values ​​of the reference block and the object to be detected are obtained simultaneously. Then, the average value of the height values ​​of each row of the reference block is obtained row by row, recorded as the average height value of each row. The average height value of each row is then averaged to obtain the total height average value. Then, the average height value of each row of the reference block is subtracted from the total height average value to obtain a difference array as the compensation array; Step 3: Use the compensation array to uniformly add the corresponding row height values ​​of the object to be detected to perform compensation correction.

2. The method for eliminating vibration errors of a laser ranging device according to claim 1, wherein: In step 2, by selecting the middle area of ​​the reference block as the ROI, the compensation array is established using the ROI of the reference block.

3. A method for eliminating vibration errors in a laser distance measuring device, used in conjunction with a point laser measuring device, wherein a reference block is provided next to the measured component, the reference block having a high degree of flatness and being placed on the same platform as the measured component, and the point laser measuring device comprises a first point laser measuring device corresponding to the measured component and a second point laser measuring device corresponding to the reference block, characterized in that The laser distance measuring device vibration error elimination method comprises the following steps: Step 1: Using the first and second point laser measuring devices to simultaneously obtain the height values ​​of the object to be detected and the reference block; Step 2: After the detection is completed, obtain multiple height values ​​of the reference block and obtain their average value, and subtract the multiple reference block height values ​​from the average value to obtain a difference array as a compensation array; Step 3: Use the compensation array to perform corresponding point correction on the height value of the object to be detected each time.

4. The method for eliminating vibration errors of a laser ranging device according to claim 3, wherein: The first point laser measuring device includes a plurality of sub-point laser measuring devices corresponding to different positions of the object to be detected.

5. The method for eliminating vibration errors of a laser ranging device according to claim 3, wherein: The second point laser measuring device includes a plurality of sub-point laser measuring devices corresponding to different positions of the reference block.

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