Displacement correction algorithm for laser collimation monitoring data

Abstract

The application discloses a displacement correction algorithm for laser collimation monitoring data and relates to the field of safety monitoring of water conservancy and hydropower projects.It comprises the following steps: step 1, grouping of measuring points;step 2, recording of distances: under a double-laser scheme, the distances from each laser collimation monitoring point and a laser emission end point to a side reference point are recorded;step 3, acquisition of data: the displacement amounts of the laser collimation monitoring points and the reference points in the same period are acquired; and step 4, correction calculation: the displacement amounts of the laser collimation monitoring points are corrected and calculated by taking the displacement amounts of the left reference point and the right reference point as true values.The monitoring values of the displacement monitoring points at the laser emission end and the laser collimation monitoring points located at the end are taken as true values, the laser collimation monitoring data are corrected and calculated, the displacement error of the measuring points caused by the instability of the laser emission end is eliminated, and the reliability of the laser collimation monitoring data is improved.

Description

Technical Field

[0001] This invention relates to the field of safety monitoring in water conservancy and hydropower projects, and more specifically, it is a displacement correction algorithm for laser collimation monitoring data. Background Technology

[0002] Laser collimation deformation monitoring system is a deformation monitoring system designed using the excellent properties of laser. It has been used for dam deformation monitoring in my country since the 1970s. It has the advantages of high observation accuracy, good long-term stability, and simple use and maintenance. It has now become the most commonly used method in dam deformation monitoring system and is often used on the dam face or horizontal gallery of straight dams.

[0003] However, after working for a certain period of time, the laser will undergo thermal deformation, or due to its own gravity or external vibration, the laser beam will not be stable at the transmitting end, causing the laser beam to drift at the measuring point; thus, the displacement of the measuring point will produce errors, which in severe cases will have a great impact on the measurement accuracy of the entire system (Reference: Zhang Lin, Yi Yaxing, Liu Zhiqin. Application of vacuum laser collimation system in dam deformation monitoring [J]. Journal of Water Resources and Architectural Engineering, 2007, (04): 111-112+116.).

[0004] Therefore, it is necessary to process the drift error of the laser collimation monitoring data to ensure the accuracy of the laser collimation monitoring data and meet the needs of engineering safety monitoring. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and to provide a displacement correction algorithm for laser collimation monitoring data.

[0006] To achieve the above objectives, the technical solution of the present invention is: a displacement correction algorithm for laser collimation monitoring data, characterized by comprising the following steps:

[0007] Step 1, Grouping of measurement points: Select the laser emitting endpoint, multiple laser collimation monitoring points, and displacement monitoring points located at the end laser collimation monitoring point to form a measurement point group;

[0008] The displacement monitoring point located at the laser collimation monitoring point at the end is referred to as the reference point, which is an existing monitoring point that can realize horizontal or vertical displacement monitoring;

[0009] In the dual-laser scheme, two lasers emit laser beams in two directions along an axis;

[0010] Step 2, record distances: In the dual-laser scheme, record the distance from each laser collimation monitoring point and the laser emission endpoint to a reference point on one side;

[0011] Where N is the total number of laser collimation monitoring points and laser emitting ends, and N≥n≥0, N≥m≥0, J N J0 is the laser collimation monitoring point on the left, and J0 is the laser collimation monitoring point on the right. m C1 is the laser emitter, and J is the laser emitter. N The left reference point for matching, C0 is the right reference point matching J0, J N The distance to C0 is S N J m The distance to C0 is S m ;

[0012] Step 3, Data Acquisition: Acquire the displacement of the laser collimation monitoring point and the reference point during the same time period; assuming the displacement of C1 is W1, the displacement of C0 is W0, and the displacement of the laser collimation monitoring point is Y. n When n = m, corresponding to the laser emitting end, there is no monitoring data, and the displacement Y... m =0;

[0013] Step 4, Correction Calculation: Using the displacements of the left and right reference points as true values, perform correction calculations on the displacements of the laser collimation monitoring points;

[0014] The displacement of the left laser collimation monitoring point plus the correction equals the displacement of the left reference point;

[0015] The displacement of the laser collimation monitoring point on the right plus the correction equals the displacement of the right reference point;

[0016] It can be seen that the correction amount of the laser collimation monitoring point on the left is W1-Y. N The correction value of the laser collimation monitoring point on the right is W0-Y0;

[0017] The ideal optical path and the actual optical path form a geometric figure. Let the correction amount at the intermediate laser collimation monitoring point be dY. n Draw auxiliary lines parallel to the ideal light path. According to the relationship of similar triangles, we have:

[0018]

[0019] Correction amount for laser collimation monitoring points:

[0020]

[0021] Therefore, for any laser collimation monitoring point, its corrected displacement Y' n for:

[0022]

[0023] The corrected displacement eliminates the error caused by the instability of the laser emitter.

[0024] In the above technical solutions, under the single-laser scheme, when the laser is emitted from left to right, m ​​= N, and when the laser is emitted from right to left, m = 0.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1) This invention uses the monitoring values ​​of the displacement monitoring point at the laser emitting end and the laser collimation monitoring point located at the end as true values ​​to correct the laser collimation monitoring data, thereby eliminating the displacement error of the measuring point caused by the instability of the laser emitting end and improving the reliability of the laser collimation monitoring data.

[0027] 2) This invention is applicable to both single-laser and dual-laser schemes, and is applicable to both horizontal and vertical displacement. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the measurement point grouping in this invention.

[0029] Figure 2 This is a schematic diagram illustrating the laser collimation monitoring data correction calculation of the present invention. Detailed Implementation

[0030] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but these descriptions are not intended to limit the invention and are merely illustrative. The advantages of the present invention will become clearer and easier to understand through this description.

[0031] Referring to the attached diagram, the displacement correction algorithm for laser collimation monitoring data is characterized by including the following steps:

[0032] Step 1, Grouping of measurement points: Select the laser emitting endpoint, multiple laser collimation monitoring points, and displacement monitoring points located at the laser collimation monitoring points at the ends to form a measurement point group;

[0033] The displacement monitoring point located at the laser collimation monitoring point at the end is referred to as the reference point. It is an existing monitoring point that can realize horizontal or vertical displacement monitoring, including tension lines, inverted plumb lines, etc.

[0034] In the dual-laser scheme, two lasers emit laser beams in two directions along an axis;

[0035] Step 2, record distances: In the dual-laser scheme, record the distance from each laser collimation monitoring point and the laser emission endpoint to a reference point on one side;

[0036] Among them, such as Figure 1 As shown, taking the right-to-left numbering as an example, N is the total number of laser collimation monitoring points and laser emitting ends, where N≥n≥0, N≥m≥0, J NJ0 is the laser collimation monitoring point on the left, and J0 is the laser collimation monitoring point on the right. m C1 is the laser emitter, and J is the laser emitter. N The left reference point for matching, C0 is the right reference point matching J0, J N The distance to C0 is S N J m The distance to C0 is S m ;

[0037] Step 3, Data Acquisition: Acquire the displacement of the laser collimation monitoring point and the reference point during the same time period; assuming the displacement of C1 is W1, the displacement of C0 is W0, and the displacement of the laser collimation monitoring point is Y. n When n = m, corresponding to the laser emitting end, there is no monitoring data, and the displacement Y... m =0;

[0038] Step 4, Correction Calculation: Using the displacements of the left and right reference points as true values, perform correction calculations on the displacements of the laser collimation monitoring points;

[0039] The displacement of the left laser collimation monitoring point plus the correction equals the displacement of the left reference point;

[0040] The displacement of the laser collimation monitoring point on the right plus the correction equals the displacement of the right reference point;

[0041] It can be seen that the correction amount of the laser collimation monitoring point on the left is W1-Y. N The correction value of the laser collimation monitoring point on the right is W0-Y0;

[0042] The ideal optical path and the actual optical path form a geometric figure. Let the correction amount at the intermediate laser collimation monitoring point be dY. n Draw auxiliary lines parallel to the ideal light path. According to the relationship of similar triangles, we have:

[0043]

[0044] Correction amount for laser collimation monitoring points:

[0045]

[0046] Therefore, for any laser collimation monitoring point, its corrected displacement Y' n for:

[0047]

[0048] The corrected displacement eliminates the error caused by the instability of the laser emitter.

[0049] In the single-laser scheme, m = N when the laser is emitted from left to right, and m = 0 when the laser is emitted from right to left; the single-laser scheme is a special case of the dual-laser scheme.

[0050] This invention uses the true values ​​of monitoring data from traditional monitoring equipment (such as tension wires, inverted plumb lines, etc.) at the laser emitting end or measuring point end to correct the monitoring data of the laser collimation monitoring point. First, the measuring points are grouped, selecting the laser emitting end point, the laser collimation monitoring point, and nearby existing displacement monitoring points to form a measuring point group. Second, distances are recorded, specifically the adjacent distance information between the laser emitting end point and the laser collimation measuring point. Then, data is acquired, including the latest monitoring data of each measuring point (including the laser collimation monitoring point and existing displacement monitoring points) at the same time or within a time period, i.e., the displacement change. Finally, the displacement of the laser collimation monitoring point is corrected based on the displacement of the existing displacement monitoring points to obtain the corrected displacement of the laser collimation monitoring point.

[0051] Example

[0052] Taking the laser collimation observation data of a hydropower station as an example, this embodiment describes the specific implementation of the method by selecting observation points JGZ01, JG401, JG402, JG403, JG404, JG405, and JG406 connected sequentially from right to left along the laser beam path. JGZ01 is the right-end laser collimation monitoring point, with the corresponding perpendicular line PL01 as the right reference point; JG406 is the left-end laser emitting end, with the corresponding perpendicular line PL02 as the left reference point. The distance from each observation point to the right end point is measured, and these points are then grouped together.

[0053] The displacement changes of each laser collimation monitoring point and the left and right reference points are obtained in 12 consecutive sets every 2 hours on a given day. These values ​​are then substituted into the formula for correction calculation to obtain the corrected changes. The standard error of the changes before and after correction is calculated. Specific data are listed in the table below.

[0054]

[0055] JG406 is the laser emission point, for which there is no observation data, and correspondingly, there is no data on the displacement error before correction. It can be seen that after correction, the horizontal and vertical displacement errors of the laser collimation monitoring point are significantly reduced, verifying the effectiveness of the correction method described in the technical solution of this invention.

[0056] All other unspecified parts belong to the prior art.

Claims

1. A displacement amount correction algorithm for laser collimation monitoring data, characterized by, Comprising the following steps, Step 1, measuring point grouping: in the double laser scheme, the laser emitting end point, multiple laser collimation monitoring points, and displacement monitoring points at the end of the laser collimation monitoring points constitute a measuring point group; The displacement monitoring point at the end of the laser collimation monitoring point is referred to as a reference point, which is an existing monitoring point capable of monitoring horizontal displacement or vertical displacement; Two lasers emit laser beams in two directions along an axis; Step 2, record the distance: in the double laser scheme, record the distance from each laser collimation monitoring point and the laser emitting end point to the reference point on one side; Wherein, N is the total number of laser collimation monitoring points and laser emitting ends, wherein N≥n≥0, N≥m≥0, J N is the laser collimation monitoring point at the left end, J0 is the laser collimation monitoring point at the right end, J m is the laser emitting end, C1 is the left reference point matched with J N , C0 is the right reference point matched with J0, J N is the distance from J to C0 N , J m is the distance from J0 to C0 m ; Step 3, data acquisition: the displacement amount of the laser collimation monitoring point and the reference point in the same period is acquired; assuming that the displacement amount of C1 is W1, the displacement amount of C0 is W0, and the displacement amount of the laser collimation monitoring point is Y n ; when n = m, it corresponds to the laser emission end, no monitoring data, and the displacement amount Y m = 0. Step 4, correction calculation: take the displacement amount of the left and right reference points as the true value to correct the displacement amount of the laser collimation monitoring points; The displacement amount of the left end laser collimation monitoring point plus the correction amount is equal to the displacement amount of the left reference point; The displacement amount of the right end laser collimation monitoring point plus the correction amount is equal to the displacement amount of the right reference point; It can be seen that the correction amount of the left end laser collimation monitoring point is W1-Y N , and the correction amount of the right end laser collimation monitoring point is W0-Y0. The ideal light path and the actual light path constitute a geometric figure, and the correction amount dY of the intermediate laser collimation monitoring point is set n An auxiliary line parallel to the ideal light path is drawn, and according to the similar triangle relationship, the following is obtained: The correction amount of the laser collimation monitoring point: Thus, for any laser collimation monitoring point, its corrected displacement amount Y' n is: The corrected displacement amount eliminates the error caused by the instability of the laser emitting end.

2. The displacement correction algorithm for laser collimation monitoring data according to claim 1, wherein, In the single laser scheme, the displacement monitoring points are located at the ends of the multiple laser collimation monitoring points and the laser emitting end. When the laser is emitted from left to right, m=N, and when the laser is emitted from right to left, m=0.

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