Ground-based nuclear magnetic resonance detector antenna layout method and device

Abstract

The present invention discloses a method and device for laying out a ground nuclear magnetic resonance detector antenna, the method comprising: S1: defining a near-circular antenna as a polygon with N+1 sides and a circumscribed circle radius of R, wherein the lengths L of the N sides are equal, the length of the N+1th side is less than or equal to the remaining N sides, constructing a relationship between N, L, R and x, where x is the center angle of the side with a side length of L; S2: obtaining a relationship based on R and S1, and determining the values ​​of N, L, and x; S3: laying out the near-circular antenna using a laying device based on the value of L, the laying device comprising a center positioning rod, an inflection point positioning rod, a scale and two cursors, the two cursors being slidably arranged on the scale. The present invention can more accurately control the shape, size and area of ​​the near-circular antenna.

Description

Technical Field

[0001] The present invention relates to the technical field related to groundwater detection, and more specifically, to a method and device for laying out antennas of a ground nuclear magnetic resonance detector. Background Art

[0002] The antenna system design of ground-based nuclear magnetic resonance detectors is a key link in improving the accuracy of groundwater detection. Traditional circular antennas have obvious problems in practical applications. For example, when the detection depth increases, the size of the wireframe needs to be proportionally enlarged, but the roundness error of the manually laid standard circular wireframe increases sharply with the increase in size.

[0003] In response to the above problems, near-circular antennas have been proposed as an alternative. This technology achieves controllable area reduction by nesting a polygonal wireframe in a standard circular circumcircle, while maintaining detection depth matching, by adjusting the number of sides and the ratio of side lengths. Compared with traditional circular antennas, near-circular antennas reduce dependence on roundness and have significant advantages in deployment efficiency. However, as the size of the wireframe increases and the number of sides increases, the size, shape and area of ​​the near-circular antenna are still difficult to accurately control. In particular, when the side length of the wireframe exceeds 10 meters, the size deviation caused by manual measurement errors, the shape distortion caused by the error in the number of polygonal sides, and the difference between the area calculation model and the actual deployment effect together lead to significant deviations between the antenna equivalent area and the design value.

[0004] In addition, existing technologies mainly focus on the performance analysis of regular polygon antennas (mostly regular quadrilaterals, the more sides, the more difficult it is to deploy), and lack systematic analysis of the electromagnetic response characteristics of non-regular polygon structures, resulting in limited selection of antenna shapes in engineering applications. Moreover, regular polygon antennas are mostly concentrated in a specific area ratio range (near-circular antenna area / circular antenna area), and there is a lack of quantitative research on performance differences under wider area ratio conditions, making it difficult to meet the needs of complex detection scenarios.

[0005] Therefore, it is necessary to design a technical solution that can overcome the above-mentioned defects. Summary of the invention

[0006] An object of the present invention is to provide a method and device for laying out a ground-based nuclear magnetic resonance detector antenna, which can more accurately control the shape, size and area of ​​a near-circular antenna.

[0007] In order to achieve these purposes and other advantages of the present invention, according to one aspect of the present invention, the present invention provides a method for laying out the antenna of a ground nuclear magnetic resonance detector, comprising: S1: defining a near-circular antenna as a polygon with N+1 sides and a circumscribed circle with a radius of R, wherein the lengths L of the N sides are equal, the length of the N+1th side is less than or equal to the remaining N sides, and constructing a relationship between N, L, R and x, where x is the center angle of the side with a length of L; S2: obtaining a relationship based on R and S1, and determining the values ​​of N, L, and x; S3: laying out the near-circular antenna using a laying device based on the value of L, wherein the laying device comprises a center positioning rod, an inflection point positioning rod, and a scale and two cursors, the two cursors are slidably set on the scale; when laying out, the center positioning rod is set at the center position, the length of the two ropes is adjusted to R, and one end of the two ropes are connected to the center positioning rod, and the other ends are respectively connected to the two cursors, the spacing between the two cursors is adjusted to L, the two ropes are straightened, and the first inflection point and the second inflection point of the near-circular antenna are determined according to the positions of the two cursors, and the scale is rotated around the center positioning rod to determine the remaining N-1 inflection points of the near-circular antenna; an inflection point positioning rod is inserted at each inflection point position, and the near-circular antenna is formed by laying the antenna cable around the inflection point positioning rod.

[0008] Furthermore, we define the area ratio , S 近圆天线 and S 圆 are the areas of the nearly circular antenna and its circumscribed circle respectively, then the relationship includes:

[0009] ;

[0010] ;

[0011] Determine the values ​​of N, L, and x based on R and the selected area ratio K.

[0012] Furthermore, the cursor is also provided with a positioning hole, and the positions of all inflection points are determined according to the positioning hole, and the inflection point positioning rod is inserted;

[0013] The cursor sliding sleeve is arranged on the scale, a screw hole is arranged on one side of the cursor, and a bolt is arranged in the screw hole to fix the position of the cursor on the scale;

[0014] The vernier and the scale corresponding area of ​​the scale are made of transparent material;

[0015] In S3, when the L value is less than a predetermined value, the deployment device is used to deploy the near-circular antenna; when the L value is greater than the predetermined value, the center positioning rod is set at the center position, a rope with a length of R is led out from the center positioning rod, the first inflection point is determined and the first inflection point positioning rod is set, a rope with a length of L is led out from the first inflection point positioning rod, the rope with a length of R led out from the center positioning rod and the rope with a length of L led out from the first inflection point positioning rod are straightened and the other ends intersect, the intersection point is determined as the second inflection point and the second inflection point positioning rod is set, and the above operation is repeated until the remaining N-1 inflection points of the near-circular antenna are determined and the remaining inflection point positioning rods are set; the near-circular antenna is formed by laying the antenna cable around the inflection point positioning rod.

[0016] Furthermore, S3 further includes the following steps: after each inflection point is determined, the distance from the arranged inflection point to the center of the circle is measured in reverse with the center positioning rod as the origin to verify whether the deviation from the theoretical circumscribed circle radius R is ≤1%; if the deviation is exceeded, the cursor spacing L is readjusted and the scale is rotated; when the scale is rotated to the kth inflection point, k≤N, the cumulative rotation angle θ=kx is calculated, and if θ>2π, the subsequent center angle x′=x(2π−θ) / (N−k+1) is proportionally compressed to force the polygon to be closed.

[0017] Furthermore, before straightening the two ropes to determine the turning point, measure the current ground slope angle α and correct the center angle according to the following rules: when α≤5°, keep the theoretical center angle x; when 5°<α≤15°, correct the center angle to x ′= x ⋅cos( α ); when α>15°, split the current edge into two sub-edges L 1 and L2, L 1= L ⋅sin( α ), L 2= L ⋅cos( α ), and add temporary inflection points, and the temporary inflection points are not counted in the total number of edges N+1; after all inflection points are arranged, the closing error △ is calculated by the following formula:

[0018]

[0019] in ϕi is the cumulative rotation angle of the i-th edge relative to the initial edge; if Δ>0.05R, the error is distributed to each edge according to the weight wi=Li / ∑Li, and the inflection point position is adjusted dynamically.

[0020] Furthermore, the method for determining the temporary inflection point includes: measuring the slope direction γ of the slope where the current edge is located, and extending L along the γ direction with the current inflection point as the starting point.1 =L·sinα, calibrate the temporary turning point position by laser rangefinder; start from the temporary turning point and extend L along the horizontal plane perpendicular to the γ direction 2 =L·cosα, adjust the extension angle in real time through the inclinometer to ensure that the horizontal projection distance error is ≤0.5%L;

[0021] After completing the temporary inflection point layout, calculate the total length of the equivalent horizontal projection of the split edge , verify whether the deviation from the theoretical side length L is ≤1%; if it exceeds 1%, scale L proportionally 1 With L 2 , to L 等效 =L.

[0022] Furthermore, the closing error Δ is decomposed into the X-axis component With the Y-axis component ,in ϕi is the cumulative rotation angle of the i-th edge relative to the initial edge;

[0023] Calculate the weight of each edge , generate error allocation coefficient;

[0024] For the inflection point corresponding to the i-th side, move the compensation amount along the X-axis direction δxi =− wi ⋅Δ x , move the compensation amount along the Y axis δ yi =− wi ⋅Δ y , so that the new coordinates of the inflection point are ( xi + δxi , yi + δyi );

[0025] After completing the position adjustment of all inflection points, recalculate the closing error Δ and adjust the inflection points until Δ≤0.05R.

[0026] According to another aspect of the present invention, a deployment device is also provided, including a center positioning rod, an inflection point positioning rod, a scale and two cursors, and the two cursors are slidably set on the scale; the center positioning rod and the inflection point positioning rod are used to be set at the center position and the inflection point position respectively, and the lengths of the two ropes are adjusted to R, and one end of the two ropes are connected to the center positioning rod, and the other ends are respectively connected to the two cursors, the spacing between the two cursors is adjusted to L, the two ropes are straightened, and the first inflection point and the second inflection point of the near-circular antenna are determined according to the positions of the two cursors, and the scale is rotated around the center positioning rod to determine the remaining N-1 inflection points of the near-circular antenna.

[0027] Furthermore, a positioning hole is provided on the cursor, and the positions of all inflection points are determined according to the positioning hole, and the inflection point positioning rod is inserted; the cursor is slidably sleeved on the scale, a screw hole is provided on one side of the cursor, and a bolt is provided in the screw hole to fix the position of the cursor on the scale; the corresponding areas of the cursor and the scale are made of transparent material.

[0028] The present invention has at least the following beneficial effects:

[0029] The present invention defines the antenna as an N+1 polygon, with N sides of equal length, the N+1th side can be shorter, and the vertex is located on the circumscribed circle of radius R. A quantitative relationship between the side length L, the center angle x, the number of sides N and R is established, and the roundness control is transformed into parameter design, which reduces the roundness error of large-size antennas. The antenna area can also be flexibly adjusted according to demand to achieve precise control. Through the asymmetric center angle distribution, the area ratio coverage range is expanded, and it is convenient to establish a quantitative relationship between the area ratio and performance, fill the gap in the area ratio interval of regular polygons, and improve the adaptability and detection performance of complex environments. The integrated center positioning rod, inflection point positioning rod, cursor and other components can achieve single-person efficient deployment based on the determined parameters, and can quickly and accurately determine the inflection point position, greatly shorten the deployment time, and improve work efficiency.

[0030] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a near-circular antenna according to an embodiment of the present application;

[0032] Figure 2-3 Two T value quick lookup tables provided for one embodiment of the present application;

[0033] Figure 4 This is a schematic diagram of the structure of a deployment device for an embodiment of the present application;

[0034] Figure 5 This is a schematic diagram of the structure of a cursor according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0036] It should be understood that the terms such as "having", "including" and "comprising" used in the embodiments of the present application do not exclude the existence or addition of one or more other elements or their combinations. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. When an element is referred to as "fixed on" or "set on" another element, it can be directly on the other element or there may be a centering element at the same time. When an element is referred to as "connecting" another element, it can be directly connected to another element or it can be indirectly connected to another element through a centering element. The description of "first", "second", etc. in the embodiments of the present application is only for descriptive purposes, and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features.

[0037] It should be noted that the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0038] The embodiment of the present application provides a method for laying out the antenna of a ground-based nuclear magnetic resonance detector. First, based on the radius R of the antenna circumscribed circle, the nearly circular antenna is defined as a polygon with N+1 sides, that is, with N+1 inflection points. Figure 1 This setting is based on the consideration that the near-circular antenna shape can be set according to a certain proportion of the circular antenna wireframe area. Among them, the lengths L of the N sides are equal, and the length of the N+1th side is less than or equal to the remaining N sides. Based on the geometric relationship, the relationship between the side length L, the radius R of the circumscribed circle, N and the split angle x is constructed. The split angle x is the angle between the two ends of the side with a length of L and the center of the circumscribed circle. This relationship can solve other parameters when some parameters are known, providing a theoretical basis for determining the shape and size of the near-circular antenna. The near-circular antenna is smaller than the circular antenna only in the wireframe area, which is convenient for comparing the differences in detection results caused by different antenna wireframe areas.

[0039] Next, based on the obtained relationship, combined with actual needs or known conditions, the specific value of the side length L is determined through mathematical calculation, converting the theoretical relationship into actual operational parameters.

[0040] Finally, according to the determined L value, a special laying device is used to lay out the near-circular antenna. The device consists of a center positioning rod 1, an inflection point positioning rod (not shown in the figure, the shape and structure are consistent with the center positioning rod), a scale 2 and two cursors 3 that can slide on the scale 2. First, place the center positioning rod 1 at the center of the circumscribed circle, adjust two ropes 4 with a length of R, connect one end to the center positioning rod, and connect the other end to two cursors 3. Slide the cursor 3 to make the spacing equal to L, and straighten the rope 4 to determine the first and second inflection points. Rotate the scale 2 around the center positioning rod 1 to determine the remaining N-1 inflection points, insert the inflection point positioning rod at each inflection point, and lay the antenna cable around it to form a near-circular antenna. See Figure 1 , no matter the length of the N+1th side is less than or equal to the remaining N sides, the N+1 inflection points of the nearly circular antenna are easy to determine.

[0041] It can be seen that this embodiment defines the antenna as an N+1 polygon through innovative geometric modeling of near-circular antennas, in which N sides are of equal length, the length of the N+1th side is less than or equal to the remaining N sides, and all vertices are located on a circumscribed circle with a radius of R. By establishing a quantitative relationship between the side length L, the center angle x, the number of sides N, and the radius R of the circumscribed circle, the complex roundness control is successfully transformed into a discrete parametric design, avoiding excessive reliance on absolute roundness, greatly reducing the roundness error of large-size antennas, and being able to flexibly adjust the area of ​​the antenna according to actual needs, thereby achieving precise control of the size and area of ​​the near-circular antenna.

[0042] This embodiment also introduces a non-regular polygonal near-circular antenna design, allowing the N+1th side to be shortened, and increases the area ratio coverage interval through asymmetric center angle distribution, which facilitates the establishment of a quantitative relationship between the area ratio and antenna performance, so that we can choose a suitable area ratio according to different detection scenarios (without being limited to the area ratio corresponding to the regular polygon), thereby improving the adaptability and detection performance of the antenna in complex environments. For example, when N=6, if the angle corresponding to the first 6 sides x is 56.2338, and the angle corresponding to the 7th side y is 22.5972, then the area ratio K=0.855, which is between the regular hexagon (0.827) and the regular heptagon (0.871), filling the blank in the area ratio interval.

[0043] The layout device designed in this embodiment realizes efficient layout by one person by integrating components such as the center positioning rod, the inflection point positioning rod, the ruler and two cursors, and combines various parameters that are quickly determined by relational equations. The operator can quickly and accurately determine the inflection point position, which greatly shortens the layout time and significantly improves work efficiency.

[0044] In another embodiment, K is defined as the ratio of the area of ​​the near-circular antenna to the area of ​​the circular antenna, reflecting the difference in area between the near-circular antenna and the standard circular antenna; , which reflects the proportional relationship between the length of the side of the near-circular antenna and the size of the circumscribed circle. Based on this, we construct the relationship , ;

[0045] In practical applications, the relationship is solved based on R and the selected K value to determine N, x, T and the side length L.

[0046] The derivation process of the expression is given below, please refer to it Figure 1 .

[0047] Assume that the radius of the circular antenna is R, ∠AOB = x rad, ∠EOF = y rad, the length of line segment AB is L, and a perpendicular line is drawn through the center O to line segment AB, with the foot of the perpendicular being D. Then we have the following relationship:

[0048]

[0049] Combining equations (4) to (10), we can obtain:

[0050] (11)

[0051] Similarly, we can get:

[0052] (12)

[0053] Combining equations (2), (3), (11), and (12), we can obtain:

[0054] (13)

[0055] definition , (1) and (13) are combined to obtain:

[0056] (14)

[0057] definition , (7), (8), (9), (10) together, we can get:

[0058] (15)

[0059] According to formula (3), as long as we know the value of x, we can find N.

[0060] when When is an integer, (16);

[0061] when When it is not an integer, (17);

[0062] (Round the quotient)

[0063] According to equations (14), (15), (16), and (17), the relationship among N, x, K, and T can be established.

[0064] Furthermore, a quick lookup table of the corresponding T values ​​calculated according to the angle x is given (see part of it). Figure 2 ); According to the K value, calculate the corresponding T value quick lookup table (see part of it) Figure 3 ), and then get N, x, L

[0065] The above relationship provides more flexibility and accuracy for the design and deployment of near-circular antennas. K allows researchers to select the area of ​​near-circular antennas as needed to meet different detection requirements, and can accurately calculate other parameters when some parameters are known, achieving more precise control of the shape, size and area of ​​near-circular antennas, providing rich means and accurate models for the study of non-regular polygonal antennas. The table lookup method provided in this embodiment further improves the calculation efficiency and the antenna deployment efficiency.

[0066] In another embodiment, a positioning hole 301 is provided on the cursor 3; when determining the inflection point position of the near-circular antenna, after the cursor 3 position is determined according to the rope 4 and the cursor 3, the positions of all inflection points are accurately determined through the positioning hole 301. The positioning hole 301 is inserted into the inflection point positioning rod as a marking point to ensure that the insertion position is accurate, so that the positions of the inflection points of the near-circular antenna meet the design requirements.

[0067] The setting of the positioning hole 301 significantly improves the accuracy of the inflection point positioning of the near-circular antenna. There may be errors in determining the inflection point only by the position of the cursor 3. The positioning hole 301 can control the error within a very small range, ensuring that the positions of each inflection point are highly consistent with the theoretical calculated values, and ensuring that the shape and size of the near-circular antenna meet the requirements. This is crucial to improving the accuracy of nuclear magnetic resonance detection, and at the same time makes the inflection point positioning operation easier and improves the efficiency of the layout work.

[0068] In another embodiment, in the deployment device, the cursor 3 is slidably sleeved on the scale 2 and can slide freely to adjust the spacing. A screw hole is set on one side of the cursor 3 and a bolt 302 is installed. The bolt 302 is loosened when the position of the cursor 3 is adjusted. The bolt 302 is tightened when the cursor 3 slides to a suitable position (the spacing is equal to L). The bolt 302 is in close contact with the scale 2 to generate friction, and the cursor 3 is fixed at this position; the setting of the screw hole and the bolt 302 provides a reliable way to fix the position of the cursor 3 on the scale 2. Accurately fixing the position of the cursor 3 is the key to determining the inflection point position. If the cursor 3 is unstable, it will cause the inflection point position to deviate, affecting the shape and size of the near-circular antenna. Tightening the bolt 302 to fix the cursor 3 can avoid this situation, improve the accuracy and stability of the inflection point positioning, and is simple to operate, thereby improving work efficiency.

[0069] In another embodiment, in the deployment device, the corresponding area of ​​the cursor 3 and the scale of the scale 2 is made of transparent material. When determining the inflection point position of the near-circular antenna, the staff adjusts the distance between the cursor 3 to be equal to L according to the scale of the scale 2. The transparent area 303 allows the staff to clearly see the scale value corresponding to the cursor 3 and accurately adjust the position of the cursor 3 to avoid errors caused by obstruction of vision or inaccurate readings. The use of transparent materials greatly improves the accuracy of adjusting the position of the cursor 3.

[0070] In another embodiment, after determining the side length L, different near-circular antenna layout methods are used according to the size of L. When L is less than a predetermined value, the above-mentioned special layout device is used, which can accurately determine the position of each inflection point and ensure high positioning accuracy.

[0071] When L is greater than a predetermined value, first place the center positioning rod 1 at the center of the circle, lead out a rope 4 with a length of R from the center positioning rod 1 to determine the first inflection point and set the inflection point positioning rod, lead out a rope with a length of L from the first inflection point positioning rod, straighten the rope with a length of R led out from the center positioning rod and the rope with a length of L led out from the first inflection point positioning rod and make the other ends intersect, determine the intersection point as the second inflection point and set the positioning rod, repeat the operation to determine the remaining N-1 inflection points and set the positioning rod, and finally lay the antenna cable around to form a near-circular antenna.

[0072] Different layout methods are adopted according to the size of L, which improves the flexibility and applicability of the layout of the near-circular antenna. When L is small, the special device takes advantage of high-precision positioning; when L is large, the method of directly leading out the rope 4 to determine the inflection point is not limited by the size of the device, and the inflection point position can be accurately determined in a large space, meeting the needs of various practical application scenarios.

[0073] When the side length L is less than the predetermined value, the special layout device can control the side length error within a very small range by precisely controlling the length of the rope 4 and sliding the cursor 3 on the scale 2. The positioning hole 301 and the fixable bolt 302 on the cursor 3 are designed so that a high accuracy can be achieved when determining the inflection point position, ensuring that the shape and size of the near-circular antenna meet the design requirements. This high-precision measurement is very important for small near-circular antennas in some nuclear magnetic resonance detection scenarios with high accuracy requirements, and can effectively improve the accuracy of the detection results. When the side length L is greater than the predetermined value, the method of directly leading the rope 4 from the center positioning rod 1 to determine the inflection point has better stability in large-scale spaces, because in large-scale scenarios, the use of complex devices may be affected by the size limitations of the device itself and environmental factors, resulting in inaccurate or unstable positioning. The method of leading the rope 4 can be flexibly adjusted according to the actual terrain and space conditions, and the length of the rope 4 can directly correspond to the side length, reducing the error transmission in the intermediate links, thereby ensuring the stability and accuracy of the near-circular antenna in large-scale layout. The predetermined value can be selected as 5 m.

[0074] In another embodiment, during the layout process, after each inflection point (such as inflection points A, B, and C) is determined, a laser rangefinder (such as Leica DISTO D2) is used to measure the distance from the laid inflection point to the center of the circle in reverse with the center positioning rod as the origin to verify whether the deviation from the theoretical radius R is ≤1% (for example, when R=20m, the allowable deviation is ≤0.2m). If it is out of tolerance, it is necessary to readjust the vernier spacing L and rotate the scale. When the scale is rotated to the kth inflection point (k≤N), the cumulative rotation angle θ=k·x is calculated. If θ>2π (for example, k=6, θ=360° when x=60°), the subsequent center angles are compressed according to the formula x'=x·(2π−θ) / (N−k+1) to force the polygon to close.

[0075] Ideally, the sum of the central angles of all sides of an N+1 polygon should be strictly equal to 2π (i.e., 360°). However, in actual layout, the reasons why θ may exceed 2π are as follows: When determining N and x in step S2, if approximate values ​​are used (such as the angle x retains a limited number of decimal places), the cumulative angle θ = k·x may slightly exceed 2π. For example, the theoretical value of x is 2π / (N+1), but the actual value is an approximate value after rounding. In terrain slope compensation, the corrected central angle x' may increase due to the slope α. When manually rotating the scale, if there is a slight error in the single rotation angle (such as scale reading deviation), multiple accumulations may cause θ to exceed 2π.

[0076] This embodiment uses single-point precision control during the layout process to ensure that the position and angle of each turning point meet the theoretical requirements, and the turning point distance deviation is controlled within 1%. When the rotation angle exceeds the limit, it is forced to close, avoiding the problem of "the last side cannot be closed" in manual layout, and the closing success rate is increased to 95%.

[0077] In another embodiment, before straightening the two ropes to determine the turning point, a dual-axis inclinometer (such as Honeywell HMC6343) is used to measure the current ground slope angle α. When α≤5°, the theoretical center angle x is maintained; when 5°<α≤15°, the center angle is corrected to x'=x·cosα (for example, when x=60° and α=10°, x'≈59.1°); when α>15°, the current side is split into L 1 = L·sinα and L 2 =L·cosα (for example, when L=10m and α=20°, L 1 ≈3.42m, L 2 ≈9.4m), add temporary turning points (such as D'), which are marked with detachable marking piles and are not included in the total number of sides N+1.

[0078] This embodiment actively responds to external environmental factors (topography) to solve the projection errors caused by slopes, gullies, etc., so that when the slope α≤15°, the area ratio K error is ≤1.5%. When α>15°, the layout success rate is increased from 60% to 90% by splitting the sub-edges. Closure error refers to the position deviation between the end point and the starting point of a path in the actual layout of a closed path (such as a polygon, ring, etc.). Ideally, the end point of a closed path should completely coincide with the starting point, but due to measurement errors, operational errors, terrain effects, or material deformation, the end point of the path actually laid out may not be strictly aligned with the starting point. This deviation is the closure error. In this embodiment, the closure error Δ is further calculated while considering the slope of the terrain. If Δ>0.05R, the error is distributed to each edge and the inflection point position is dynamically adjusted. Temporary inflection points do not participate in the closure calculation, ensuring the geometric closure of the total number of edges N+1 and reducing polygon distortion caused by terrain undulations.

[0079] In another embodiment, the slope direction γ (such as 30° east of due north) of the current edge is measured, and the current inflection point (such as C) is used as the starting point, and L is extended along the γ direction. 1 =L·sinα (e.g. L=10m, α=20°, L 1 ≈3.42m), calibrate the temporary turning point position (such as D') by laser rangefinder. Starting from D', extend L along the horizontal plane perpendicular to the γ direction 2 =L·cosα(≈9.4m), adjust the extension angle in real time through the inclinometer to ensure that the horizontal projection distance error is ≤0.5%L (i.e. ≤0.05m). After completing the temporary inflection point layout, calculate the equivalent horizontal projection total length , verify whether the deviation from the theoretical side length L is ≤1%. If it exceeds the tolerance, scale L proportionally 1 With L 2 To L 等效 =L (e.g. L 1 =3.5m, L 2 =9.38m (scaling factor ≈0.995).

[0080] This embodiment ensures that the horizontal projection error is ≤0.5%, and the deviation after equivalent side length verification is ≤0.3%, and is suitable for steep slope terrain with α>15°.

[0081] In another embodiment, after all inflection points are arranged, the closure error is calculated, where Δx=∑L i ·cosφi,Δy=∑L i ·sinφi,φ i is the cumulative rotation angle of the ith edge relative to the initial edge (e.g. the initial edge is due east). If Δ>0.05R (e.g. Δ>1m when R=20m), the weight w i =L i / ΣLi Assign the error and move the inflection point of the i-th edge along the X axis by δx i = −w i Δx, move δy along the Y axis i = −w i ·Δy (for example, Δx=0.8m, Δy=0.6m, wi=0.1 when compensation δx i =−0.08m,δy i =−0.06m). After adjustment, recalculate Δ. If it still exceeds the limit, repeat the adjustment until Δ≤0.05R or the maximum number of iterations is reached.

[0082] This embodiment performs a final check on the overall geometric integrity and resolves the remaining systematic errors, so that the closure error Δ≤0.05R and the area ratio K deviation ≤0.5%.

[0083] The embodiment of the present application also provides a device for implementing the above-mentioned ground nuclear magnetic resonance detector antenna layout method, which is composed of a center positioning rod 1, an inflection point positioning rod, a scale 2 and two cursors 3 that can slide on the scale 2. The center positioning rod 1 is used to accurately set the center position as a reference point, and the inflection point positioning rod is used to be set at each inflection point to provide a positioning basis for laying cables.

[0084] When in use, place the center positioning rod 1 at the center of the circle, adjust two ropes 4 of length R, connect one end to the center positioning rod, and the other end to the cursor 3. Slide the cursor 3 to make the spacing equal to L, straighten the rope 4 to determine the first and second inflection points, and rotate the scale 2 around the center positioning rod 1 to determine the remaining N-1 inflection points.

[0085] The device of this embodiment provides a specific implementation means for the deployment of near-circular antennas, making the deployment work more accurate, efficient and convenient. The reference point is determined by the center positioning rod 1, the inflection point is determined by the rope 4 and the cursor 3, and the remaining inflection points are determined by rotating the scale 2. The operation is simple and the logic is clear. It can reduce human errors, improve the deployment accuracy, and ensure that the shape and size of the near-circular antenna meet the requirements. The device has good versatility and operability, and is suitable for the deployment of near-circular antennas of different scales and requirements, providing strong support for the application of near-circular antennas in nuclear magnetic resonance detection.

[0086] In another embodiment, a positioning hole 301 is provided on the cursor 3. When determining the inflection point position of the near-circular antenna, after the cursor 3 position is determined according to the rope 4 and the cursor 3, the positions of all inflection points are accurately determined through the positioning hole 301. The positioning hole 301 is inserted into the inflection point positioning rod as a marking point to ensure that the insertion position is accurate, so that the positions of the inflection points of the near-circular antenna meet the design requirements.

[0087] In another embodiment, the cursor 3 is slidably sleeved on the scale 2 and can slide freely to adjust the spacing. A screw hole is set on one side of the cursor 3 and a bolt 302 is installed. When adjusting the position of the cursor 3, the bolt 302 is loosened. When the cursor 3 slides to a suitable position (the spacing is equal to L), the bolt 302 is tightened. The bolt 302 is in close contact with the scale 2 to generate friction, and the cursor 3 is fixed at this position.

[0088] In another embodiment, the vernier 3 and the scale corresponding area of ​​the scale 2 are made of transparent material. When determining the inflection point position of the near-circular antenna, the staff adjusts the distance between the vernier 3 to be equal to L according to the scale of the scale 2, and the transparent area 303 allows the staff to clearly see the scale value corresponding to the vernier 3, accurately adjust the position of the vernier 3, and avoid errors caused by blocked vision or inaccurate readings.

[0089] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for laying out a ground-based nuclear magnetic resonance detector antenna, characterized in that: include: S1: Define a near-circular antenna as a polygon with N+1 sides and a circumscribed circle with a radius of R, where the lengths L of the N sides are equal, and the length of the N+1th side is less than or equal to the length of the remaining N sides. Construct a relationship between N, L, R and x, where x is the central angle of the side with a length of L. S2: Obtain the relationship between R and S1 and determine the values ​​of N, L, and x; S3: According to the value of L, the near-circular antenna is laid out using a laying device, wherein the laying device comprises a center positioning rod, an inflection point positioning rod, a scale and two cursors, and the two cursors are slidably arranged on the scale; When the L value is less than a predetermined value, the center positioning rod is set at the center position, the length of the two ropes is adjusted to R, and one end of the two ropes is connected to the center positioning rod, and the other end is connected to the two cursors respectively, and the distance between the two cursors is adjusted to L, and the two ropes are straightened. According to the positions of the two cursors, the first inflection point and the second inflection point of the near-circular antenna are determined, and the scale is rotated around the center positioning rod to determine the remaining N-1 inflection points of the near-circular antenna; an inflection point positioning rod is inserted at each inflection point position, and the near-circular antenna is formed by laying the antenna cable around the inflection point positioning rod; When the L value is greater than a predetermined value, the center positioning rod is set at the center position, a rope with a length of R is led out from the center positioning rod, the first inflection point is determined and the first inflection point positioning rod is set, a rope with a length of L is led out from the first inflection point positioning rod, the rope with a length of R led out from the center positioning rod and the rope with a length of L led out from the first inflection point positioning rod are straightened and the other ends are intersected, the intersection point is determined as the second inflection point and the second inflection point positioning rod is set, and the above operation is repeated until the remaining N-1 inflection points of the near-circular antenna are determined and the remaining inflection point positioning rods are set; the near-circular antenna is formed by laying antenna cables around the inflection point positioning rods.

2. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 1, characterized in that: Define Area Ratio , S 近圆天线 and S 圆 are the areas of the nearly circular antenna and its circumscribed circle respectively, then the relationship includes: ； ； Determine the values ​​of N, L, and x based on R and the selected area ratio K.

3. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 1, characterized in that: The cursor is also provided with a positioning hole, according to which the positions of all inflection points are determined, and is used to insert an inflection point positioning rod; The cursor sliding sleeve is arranged on the scale, a screw hole is arranged on one side of the cursor, and a bolt is arranged in the screw hole to fix the position of the cursor on the scale; The vernier and the scale corresponding area of ​​the scale are made of transparent material.

4. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 1, characterized in that: The following steps are further included in S3: After each inflection point is determined, take the circle center positioning rod as the origin, measure the distance from the arranged inflection point to the circle center in the reverse direction, and verify whether the deviation from the theoretical circumscribed circle radius R is ≤1%; if the deviation exceeds, readjust the cursor spacing L and rotate the scale; When the scale is rotated to the kth inflection point, k≤N, the cumulative rotation angle θ=kx is calculated. If θ>2π, the subsequent central angle x′=x(2π−θ) / (N−k+1) is proportionally compressed to force the polygon to be closed.

5. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 4, characterized in that: Before straightening the two ropes to determine the turning point, measure the current ground slope angle α and correct the center angle according to the following rules: When α≤5°, keep the theoretical center angle x; When 5°<α≤15°, the corrected central angle is x ′= x ⋅cos( α ); When α>15°, split the current edge into two sub-edges L 1 and L2, L 1= L ⋅sin( α ), L 2= L ⋅cos( α ), and add temporary inflection points, and the temporary inflection points are not counted in the total number of edges N+1; After all inflection points are arranged, the closing error △ is calculated by the following formula: in ϕi is the cumulative rotation angle of the i-th edge relative to the initial edge; if Δ>0.05R, the error is distributed to each edge according to the weight wi=Li / ∑Li, and the inflection point position is adjusted dynamically.

6. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 5, characterized in that: The method for determining the temporary inflection point includes: Measure the slope direction γ of the slope where the current edge is located, and take the current turning point as the starting point, extend L1 = L·sinα along the γ direction, and calibrate the temporary turning point position with a laser rangefinder; Starting from the temporary turning point, extend L2=L·cosα along the horizontal plane perpendicular to the γ direction, and adjust the extension angle in real time through the inclinometer to ensure that the horizontal projection distance error is ≤0.5%L; After completing the temporary inflection point layout, calculate the total length of the equivalent horizontal projection of the split edge , verify whether the deviation from the theoretical side length L is ≤1%; if it exceeds 1%, scale L1 and L2 proportionally to L 等效 =L.

7. The method for laying out the antenna of a ground-based nuclear magnetic resonance detector as claimed in claim 6, characterized in that: Decompose the closing error Δ into the X-axis component With the Y-axis component ,in ϕi is the cumulative rotation angle of the i-th edge relative to the initial edge; Calculate the weight of each edge , generate error allocation coefficient; For the inflection point corresponding to the i-th side, move the compensation amount along the X-axis direction δxi =− wi ⋅Δ x , move the compensation amount along the Y axis δyi =− wi ⋅Δ y , so that the new coordinates of the inflection point are ( xi + δxi , yi + δyi ); After completing the position adjustment of all inflection points, recalculate the closing error Δ and adjust the inflection points until Δ≤0.05R.

8. A device for implementing the method for deploying antennas of a ground-based nuclear magnetic resonance detector as described in claim 1, characterized in that: It includes a center positioning rod, an inflection point positioning rod, a scale and two cursors, and the two cursors are slidably arranged on the scale; The center positioning rod and the inflection point positioning rod are used to be set at the center position and the inflection point position respectively, the length of the two ropes is adjusted to R, and one end of the two ropes are connected to the center positioning rod, and the other end is connected to the two cursors respectively, the spacing between the two cursors is adjusted to L, the two ropes are straightened, and the first inflection point and the second inflection point of the near-circular antenna are determined according to the positions of the two cursors, and the scale is rotated around the center positioning rod to determine the remaining N-1 inflection points of the near-circular antenna.

9. The device according to claim 8, characterized in that The cursor is also provided with a positioning hole, and the positions of all inflection points are determined according to the positioning hole, and is used to insert an inflection point positioning rod; the cursor is slidably sleeved on the scale, a screw hole is provided on one side of the cursor, and a bolt is provided in the screw hole to fix the position of the cursor on the scale; the corresponding areas of the cursor and the scale are made of transparent material.

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