Petrochemical spherical tank 2D map construction method for high-altitude wall-climbing detection robot

Abstract

The invention discloses a petrochemical spherical tank 2D map construction method for a high-altitude wall-climbing detection robot. The petrochemical spherical tank 2D map construction method comprises the following steps: step 1, dividing a spherical tank region; step 2, welding seam measurement; step 3, constructing a two-dimensional map of the welding seam of the upper polar band; 4, constructing a lower polar band welding seam two-dimensional map; step 5, constructing a two-dimensional map of the weld joints of the intermediate zone: performing scaling deformation on all the weld joints and cross points of the intermediate zone by setting a mapping proportionality coefficient to form the two-dimensional map of the intermediate zone; and step 6, constructing a spherical tank weld length data set. According to the method, the spherical tank is longitudinally divided into three parts, the position coordinates of the intersection point of the welding seam and the actual length of the welding seam are obtained, the proportional relation is set, scaling is carried out on the position coordinates, and the three parts of the spherical tank are mapped to the 2D plane from 3D through coordinate system conversion, so that the relative position maps of the three parts of the spherical tank in the 2D plane are constructed in sequence; and then constructing a data set to represent the real length of the spherical tank weld joint.

Description

Technical Field

[0001] The invention relates to the technical field of two-dimensional graphics processing and mapping, in particular to a method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall climbing detection robot. Background Art

[0002] With the rapid development of petrochemical, natural gas, electric power and other industries, large spherical tanks, vertical storage tanks and other special equipment are being used more and more widely. These equipment are usually used to store high-risk chemicals such as liquefied natural gas, liquid hydrocarbons, liquid ammonia, etc., and are pressure-bearing special equipment. Once a leak or explosion occurs, it may cause serious casualties, huge economic losses and environmental pollution. Therefore, regular inspection and maintenance of the welds of large storage tanks such as spherical tanks is the key to ensure their safe operation.

[0003] Traditional weld inspection usually relies on manual operation, and the quality of welds is evaluated through non-destructive testing technologies such as X-ray and ultrasound. However, with the development of industrial automation and intelligent robot technology, the detection and flaw detection tasks have gradually shifted from manual operation to automation and intelligence. Especially in dangerous environments such as high temperature, high pressure, and narrow space, it has become a trend for robots to replace manpower for weld inspection. In recent years, automated robot equipment based on non-destructive testing technologies such as X-ray digital flat panel and ultrasonic TOFD has played an important role in the inspection of special equipment such as spherical tanks.

[0004] However, there are still some challenges in weld inspection for equipment such as spherical tanks, especially in terms of how to accurately obtain the spatial distribution information of welds. There is still a lack of efficient two-dimensional weld map construction methods. In order to improve the efficiency and accuracy of weld inspection, there is an urgent need for a technology that can convert the three-dimensional spatial information of spherical tank welds into a two-dimensional plane map. By constructing a 2D map of spherical tank welds, more intuitive weld distribution information can be provided to robots or inspectors, thereby helping automated equipment to perform inspection tasks more accurately and improving inspection efficiency and accuracy. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a 2D map construction method for a petrochemical spherical tank for a high-altitude wall climbing detection robot in view of the deficiencies of the above-mentioned prior art. The 2D map construction method for a petrochemical spherical tank for a high-altitude wall climbing detection robot maps the three-dimensional weld distribution of the spherical tank to a two-dimensional plane, and combines information such as weld length and intersection points to generate a clear weld distribution map. This method can not only significantly improve the efficiency of weld detection, but also provide a basic basis for line patrol control and weld quality assessment of automated equipment, which is of great significance to ensuring the safe operation of special equipment such as spherical tanks.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot comprises the following steps.

[0008] Step 1. Spherical tank area division: The spherical tank has an upper circumferential weld and a lower circumferential weld. The spherical tank area above the upper circumferential weld is called the upper pole zone, the spherical tank area below the lower circumferential weld is called the lower pole zone, and the spherical tank area between the upper pole zone and the lower pole zone is called the middle zone.

[0009] Step 2: Weld measurement: Measure the actual length of each weld on the spherical tank. r .

[0010] Step 3. Construct a two-dimensional map of the upper pole belt welds: From the top-down view of the spherical tank, obtain the intersection points of the welds in the upper pole belt and the relative position distribution of the welds, project the actual weld length in the upper pole belt onto a two-dimensional plane, and construct a two-dimensional map of the upper pole belt welds with the relative position relationship of the welds.

[0011] Step 4, construct a two-dimensional map of the lower pole belt welds: from the upward angle of the spherical tank, obtain the intersection points of the welds in the lower pole belt and the relative position distribution of the welds, project the actual weld length in the lower pole belt onto a two-dimensional plane, and construct a two-dimensional map of the lower pole belt welds with the relative position relationship of the welds;

[0012] Step 5, constructing a two-dimensional map of the intermediate zone welds: by setting the mapping scale coefficient, the upper circular welds and the weld intersections on the upper circular welds, the lower circular welds and the weld intersections on the lower circular welds, and all welds and intersections between the upper circular welds and the lower circular welds are scaled and deformed to form a two-dimensional map of the intermediate zone.

[0013] Step 6: Construct a spherical tank weld length dataset: For each weld constructed in steps 3 to 5, save the actual weld length l measured in step 2 r .

[0014] In step 1, the spherical tank also has a mid-circumferential weld located between the upper circumferential weld and the lower circumferential weld; the spherical tank area located between the upper circumferential weld and the mid-circumferential weld is called the upper temperature zone; the spherical tank area located between the lower circumferential weld and the mid-circumferential weld is called the lower temperature zone; the upper temperature zone and the lower temperature zone together constitute the middle zone.

[0015] In step 5, the welds and weld intersections are scaled and deformed by setting the mapping coefficients [η1, η2, η3, η4, η5] to form a two-dimensional map of the middle zone; where:

[0016] η1 is used to synchronously scale the upper circumferential weld and all weld intersections on the upper circumferential weld.

[0017] η2 is used to synchronously scale the weld length in the upper temperate zone.

[0018] η3 is used to synchronously scale the mid-circumferential weld and all weld intersections on the mid-circumferential weld.

[0019] η4 is used to synchronously scale the weld length in the lower temperate zone.

[0020] η5 is used to synchronously scale the lower circumferential weld and all weld intersections on the lower circumferential weld.

[0021] Among them, η5>η3>η1, so that in the two-dimensional map of the intermediate zone, the upper circumferential weld, the middle circumferential weld and the lower circumferential weld form a concentric circle structure arranged in sequence from the inside to the outside, the upper temperate zone weld and the lower temperate zone weld are arranged radially, the two ends of the upper temperate zone weld are respectively connected to the upper circumferential weld and the middle circumferential weld, and the two ends of the lower temperate zone weld are respectively connected to the middle circumferential weld and the lower circumferential weld.

[0022] In step 5, η2=η4=2η1.

[0023] In step 5, the upper temperate zone welds and the lower temperate zone welds are arranged alternately along the circumferential direction.

[0024] In step 5, the method for constructing the two-dimensional map of the intermediate zone weld includes the following steps:

[0025] Step 5-1, construct the upper circumferential weld: the upper circumferential weld and all weld intersections C1-Cn located on the upper circumferential weld are synchronously scaled with the mapping coefficient η1; wherein the scaled length l1' of each upper circumferential weld is η1 times its actual length l1; and the coordinates of each upper circumferential weld intersection are η1 times the actual coordinates.

[0026] Step 5-2, construct the upper temperate zone weld: starting from the intersection point C1-Cn of the upper circumferential weld, construct the upper temperate zone weld with a length of l'2 in the radial direction, and the tail end points are D1-Dn respectively; where l'2=l2·η2, l2 is the actual length of the upper temperate zone weld.

[0027] Step 5-3, constructing a mid-circumferential weld: the mid-circumferential weld and some weld intersections F1-Fn located on the mid-circumferential weld are synchronously scaled with a mapping coefficient η3, and the tail end points D1-Dn are all located on the mid-circumferential weld, and the weld intersections F1-Fn are equidistantly staggered along the circumferential direction; wherein the scaled length l3' of each mid-circumferential weld is η3 times its actual length l3; the coordinates of each mid-circumferential weld intersection are η3 times the actual coordinates; D1-Dn and F1-Fn together constitute the mid-circumferential weld intersection.

[0028] Step 5-4, construct the lower temperate zone weld: starting from the mid-circumferential weld intersection F1-Fn, construct the lower temperate zone weld with a length of l'4 in the radial direction, and the tail end points are E1-En respectively; wherein l'4=l4·η4, l4 is the actual length of the lower temperate zone weld.

[0029] Step 5-5, construct the lower circular weld: scale the lower circular weld with the mapping coefficient η5, and make the tail end points E1-En all located on the lower circular weld, and form the lower circular weld intersection; wherein, the scaled length l5' of each lower circular weld is η5 times its actual length l5; the coordinates of each lower circular weld intersection are η5 times the actual coordinates.

[0030] In step 3, in the two-dimensional map of the upper pole belt weld, each line segment intersection point represents the intersection point of the actual weld, represented by letters A1-An; in step 4, in the two-dimensional map of the lower pole belt weld, each line segment intersection point represents the intersection point of the actual weld, represented by letters B1-Bn.

[0031] In step 6, the welds are divided into n categories according to the weld length of the spherical tank, and n weld length coefficients [k1, k2, k3, L, k n ], so that the true length of each weld can be saved. Among them, the true length of the i-th type weld is l ri The saving method is: ri =k i πR c ; where k i Represents the length coefficient of the i-th type weld, 1≤i≤n; R c is the radius of the spherical tank.

[0032] In step 6, n=8, which are the upper / lower polar zone oblique weld, the upper / lower polar zone transverse edge weld, the upper / lower polar zone transverse center weld, the upper / lower polar zone longitudinal weld, the upper / lower circumferential weld, the upper temperate zone weld, the mid-circumferential weld and the lower temperate zone weld; 8 weld length coefficients [k1, k2, k3, L, k8] are set to save the actual lengths of the 8 types of welds.

[0033] k1=0.0645; k2=0.0967; k3=0.0806; k4=0.2546; k5=0.0707; k6=0.2220; k7=0.0978

[0034] And k8=0.2779.

[0035] The present invention has the following beneficial effects:

[0036] 1. The present invention divides the spherical tank into three parts along its longitudinal direction: the upper polar zone, the middle polar zone and the lower polar zone, obtains the position coordinates and actual length of the weld intersection respectively, establishes a proportional relationship for scaling and coordinate system conversion, and realizes accurate drawing of the three parts in the 2D plane. In particular, by combining the top view and the bottom view of the spherical tank, the representation of the weld intersection and length on the 2D map is more accurate, thereby providing reliable reference data for subsequent weld path detection and planning.

[0037] 2. The present invention uses the positions of the weld intersections obtained from the top view and bottom view of the spherical tank to accurately map the three-dimensional welds to the 2D plane through coordinate system conversion and proportional relationship. Such a high-precision coordinate mapping method ensures the accurate representation of the weld intersections and lengths in the 2D map, avoids the errors that may occur in traditional methods, and improves the navigation and detection accuracy of the robot in the actual detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the vertical division diagram of the spherical tank 3D map.

[0039] Figure 2 2D map of the upper pole of the spherical tank.

[0040] Figure 3 It is a 2D map of the lower pole of the spherical tank.

[0041] Figure 4 2D map of the temperate weld on the spherical tank.

[0042] Figure 5 2D map of the temperate weld under the spherical tank.

[0043] Figure 6 2D map of the median weld.

[0044] Among them are:

[0045] 10. Upper pole belt; 11. Upper pole belt oblique weld; 12. Upper pole belt transverse edge weld; 13. Upper pole belt transverse center weld; 14. Upper pole belt longitudinal weld; 15. Upper pole belt weld intersection;

[0046] 20. Middle belt;

[0047] 21. Upper temperate zone; 211. Upper temperate zone weld;

[0048] 22. Lower temperate zone; 221. Lower temperate zone weld;

[0049] 30. Lower pole belt; 31. Lower pole belt oblique weld; 32. Lower pole belt transverse edge weld; 33. Lower pole belt transverse center weld; 34. Lower pole belt longitudinal weld; 35. Lower pole belt weld intersection;

[0050] 40. Upper circumferential weld; 41. Upper circumferential weld intersection;

[0051] 50. Mid-circumferential weld; 51. Mid-circumferential weld intersection;

[0052] 60. Lower circumferential weld; 61. Intersection point of lower circumferential weld. DETAILED DESCRIPTION

[0053] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0054] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0055] A method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot comprises the following steps.

[0056] Step 1: Spherical tank area division

[0057] like Figure 1 As shown, the spherical tank has an upper circumferential weld 40, a middle circumferential weld 50 and a lower circumferential weld 60. The area of ​​the spherical tank above the upper circumferential weld is called the upper polar zone 10, the area of ​​the spherical tank below the lower circumferential weld is called the lower polar zone 30, the area of ​​the spherical tank between the upper circumferential weld and the middle circumferential weld is called the upper temperature zone 21; the area of ​​the spherical tank between the lower circumferential weld and the middle circumferential weld is called the lower temperature zone 22; the upper temperature zone and the lower temperature zone together constitute the middle zone 20.

[0058] Step 2: Weld measurement: Measure the actual length of each weld on the spherical tank. r .

[0059] Step 3: Construct a 2D map of the upper pole weld

[0060] like Figure 2 As shown, from the top view of the spherical tank, the intersection points of the welds in the upper pole belt and the relative position distribution of the welds are obtained, and the actual weld length in the upper pole belt is projected onto a 2D plane to construct a two-dimensional map of the upper pole belt welds with the relative position relationship of the welds. In the two-dimensional map of the upper pole belt welds, each line segment intersection represents the intersection point of the actual weld, also called the upper pole belt weld intersection 15, represented by letters A1-An.

[0061] exist Figure 2 In the embodiment, the upper pole band preferably has four types of welds of different lengths, namely, the upper pole band oblique weld 11, the upper pole band transverse edge weld 12, the upper pole band transverse center weld 13 and the upper pole band longitudinal weld 14.

[0062] Step 4: Construct a 2D map of the lower pole weld

[0063] like Figure 3 As shown, from the upward angle of the spherical tank, the intersection points of the welds in the lower polar zone and the relative position distribution of the welds are obtained, and the actual weld length in the lower polar zone is projected onto a 2D plane to construct a lower polar zone weld 2D map with the relative position relationship of the welds. In the lower polar zone weld 2D map, each line segment intersection point represents the intersection point of the actual weld, also called the lower polar zone weld intersection point 35, represented by letters B1-Bn.

[0064] exist Figure 3 In the embodiment, the lower pole band preferably has four types of welds of different lengths, namely, the lower pole band oblique weld 31, the lower pole band transverse edge weld 32, the lower pole band transverse center weld 33 and the lower pole band longitudinal weld 34.

[0065] Step 5: Construct a 2D map of the middle zone weld

[0066] By setting the mapping scale coefficient, the upper circular weld and the weld intersections on the upper circular weld, the lower circular weld and the weld intersections on the lower circular weld, and all welds and intersections between the upper circular weld and the lower circular weld are scaled and deformed to form a two-dimensional map of the middle zone.

[0067] Furthermore, it is preferred to set mapping coefficients [η1, η2, η3, η4, η5] to scale and deform the welds and weld intersections to form a two-dimensional map of the middle zone; wherein:

[0068] η1 is used to synchronously scale the upper circumferential weld and all weld intersections on the upper circumferential weld.

[0069] η2 is used to synchronously scale the weld length in the upper temperate zone.

[0070] η3 is used to synchronously scale the mid-circumferential weld and all weld intersections on the mid-circumferential weld.

[0071] η4 is used to synchronously scale the weld length in the lower temperature zone, preferably η2=η4=2η1.

[0072] η5 is used to synchronously scale the lower circumferential weld and all weld intersections on the lower circumferential weld.

[0073] Among them, η5>η3>η1, so that in the two-dimensional map of the intermediate zone, the upper circumferential weld, the middle circumferential weld and the lower circumferential weld form a concentric circle structure arranged from the inside to the outside, and the upper temperate zone weld and the lower temperate zone weld are arranged radially and staggered circumferentially. The two ends of the upper temperate zone weld are respectively connected to the upper circumferential weld and the middle circumferential weld, and the two ends of the lower temperate zone weld are respectively connected to the middle circumferential weld and the lower circumferential weld.

[0074] like Figures 4 to 6 As shown, the method for constructing the above-mentioned two-dimensional map of the intermediate zone weld includes the following steps.

[0075] Step 5-1, constructing the upper circumferential weld: the upper circumferential weld and all weld intersections C1-Cn (also referred to as upper circumferential weld intersections 41) located on the upper circumferential weld are synchronously scaled with a mapping coefficient η1; wherein the scaled length l1' of each upper circumferential weld is η1 times its actual length l1; and the coordinates of each upper circumferential weld intersection 41 are η1 times the actual coordinates.

[0076] Step 5-2, constructing the upper temperate zone weld: starting from the intersection points C1-Cn of the upper circumferential welds, constructing the upper temperate zone welds 211 with a length of l'2 in the radial direction, and the tail end points are D1-Dn respectively; wherein l'2=l2·η2, l2 is the actual length of the upper temperate zone weld.

[0077] Step 5-3, constructing a mid-circumferential weld: the mid-circumferential weld and some weld intersections F1-Fn located on the mid-circumferential weld are synchronously scaled with a mapping coefficient η3, and the tail end points D1-Dn are all located on the mid-circumferential weld, and the weld intersections F1-Fn are equidistantly staggered along the circumferential direction; wherein the scaled length l3' of each mid-circumferential weld is η3 times its actual length l3; the coordinates of each mid-circumferential weld intersection are η3 times the actual coordinates; D1-Dn and F1-Fn together constitute the mid-circumferential weld intersection 51.

[0078] Step 5-4, constructing the lower temperate zone weld: starting from the mid-circumferential weld intersection F1-Fn, construct the lower temperate zone weld 221 with a length of l'4 in the radial direction, and the tail end points are E1-En respectively; wherein l'4=l4·η4, l4 is the actual length of the lower temperate zone weld.

[0079] Step 5-5, constructing the lower circular weld: scale the lower circular weld with a mapping coefficient η5, and make the tail end points E1-En all located on the lower circular weld, and form a lower circular weld intersection 61; wherein, the scaled length l5' of each lower circular weld is η5 times its actual length l5; and the coordinates of each lower circular weld intersection are η5 times the actual coordinates.

[0080] Step 6: Construct a spherical tank weld length dataset: For each weld constructed in steps 3 to 5, save the actual weld length l measured in step 2 r .

[0081] Furthermore, according to the weld length of the spherical tank, the welds are preferably divided into n categories, and n weld length coefficients [k1, k2, k3, L, k n ] so that the true length of each weld can be saved.

[0082] In this embodiment, n is preferably 8, which are upper / lower polar band oblique welds (such as A1A2, A5A6, etc.), upper / lower polar band transverse edge welds (such as A2A3, A4A5, etc.), upper / lower polar band transverse center welds (such as A3A4, A9A10, etc.), upper / lower polar band longitudinal welds (such as A2A11, A3A10, etc.), upper / lower circumferential welds, upper temperate zone welds, mid-circumferential welds and lower temperate zone welds; by setting 8 weld length coefficients [k1, k2, k3, L, k8], the actual lengths of 8 types of welds can be saved.

[0083] The above eight weld length coefficients are preferably: k1=0.0645; k2=0.0967; k3=0.0806; k4=0.2546; k5=0.0707; k6=0.2220; k7=0.0978 and k8=0.2779.

[0084] The actual length l of the i-th type weld among the above 8 welds ri The saving method is: ri =k i πR c ; where k i Represents the length coefficient of the i-th type weld, 1≤i≤8; R c is the radius of the spherical tank.

[0085] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot, characterized in that: The steps include: Step 1: Spherical tank area division: The spherical tank has an upper circumferential weld and a lower circumferential weld. The spherical tank area above the upper circumferential weld is called the upper pole zone, the spherical tank area below the lower circumferential weld is called the lower pole zone, and the spherical tank area between the upper pole zone and the lower pole zone is called the middle zone; Step 2: Weld measurement: Measure the actual length of each weld on the spherical tank. r ; Step 3, constructing a two-dimensional map of the upper pole belt welds: from the top view of the spherical tank, obtain the intersection points of the welds in the upper pole belt and the relative position distribution of the welds, project the actual weld length in the upper pole belt onto a two-dimensional plane, and construct a two-dimensional map of the upper pole belt welds with the relative position relationship of the welds; Step 4, construct a two-dimensional map of the lower pole belt welds: from the upward angle of the spherical tank, obtain the intersection points of the welds in the lower pole belt and the relative position distribution of the welds, project the actual weld length in the lower pole belt onto a two-dimensional plane, and construct a two-dimensional map of the lower pole belt welds with the relative position relationship of the welds; Step 5, constructing a two-dimensional map of the intermediate zone welds: by setting a mapping scale coefficient, scaling and deforming the upper circumferential welds and weld intersections on the upper circumferential welds, the lower circumferential welds and weld intersections on the lower circumferential welds, and all welds and intersections between the upper circumferential welds and the lower circumferential welds to form a two-dimensional map of the intermediate zone; Step 6: Construct a spherical tank weld length dataset: For each weld constructed in steps 3 to 5, save the actual weld length l measured in step 2 r .

2. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 1, characterized in that: In step 1, the spherical tank also has a mid-circumferential weld located between the upper circumferential weld and the lower circumferential weld; the spherical tank area located between the upper circumferential weld and the mid-circumferential weld is called the upper temperature zone; the spherical tank area located between the lower circumferential weld and the mid-circumferential weld is called the lower temperature zone; the upper temperature zone and the lower temperature zone together constitute the middle zone.

3. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 2, characterized in that: In step 5, the welds and weld intersections are scaled and deformed by setting the mapping coefficients [η1, η2, η3, η4, η5] to form a two-dimensional map of the middle zone; where: η1 is used to synchronously scale the upper circumferential weld and all weld intersections on the upper circumferential weld; η2 is used to synchronously scale the weld length in the upper temperate zone; η3 is used to synchronously scale the mid-circumferential weld and all weld intersections on the mid-circumferential weld; η4 is used to synchronously scale the weld length in the lower temperate zone; η5 is used to synchronously scale the lower circumferential weld and all weld intersections on the lower circumferential weld; Among them, η5>η3>η1, so that in the two-dimensional map of the intermediate zone, the upper circumferential weld, the middle circumferential weld and the lower circumferential weld form a concentric circle structure arranged in sequence from the inside to the outside, the upper temperate zone weld and the lower temperate zone weld are arranged radially, the two ends of the upper temperate zone weld are respectively connected to the upper circumferential weld and the middle circumferential weld, and the two ends of the lower temperate zone weld are respectively connected to the middle circumferential weld and the lower circumferential weld.

4. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 3 is characterized in that: In step 5, η2=η4=2η1.

5. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 4, characterized in that: In step 5, the upper temperate zone welds and the lower temperate zone welds are arranged alternately along the circumferential direction.

6. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 5, characterized in that: In step 5, the method for constructing the two-dimensional map of the intermediate zone weld includes the following steps: Step 5-1, constructing the upper circumferential weld: the upper circumferential weld and all weld intersections C1-Cn located on the upper circumferential weld are synchronously scaled by the mapping coefficient η1; wherein the scaled length l1' of each upper circumferential weld is η1 times its real length l1; and the coordinates of each upper circumferential weld intersection are η1 times the real coordinates; Step 5-2, constructing the upper temperate zone weld: starting from the intersection points C1-Cn of the upper circumferential welds, construct upper temperate zone welds of length l'2 along the radial direction, and the end points are D1-Dn respectively; wherein l'2=l2·η2, l2 is the actual length of the upper temperate zone weld; Step 5-3, constructing a mid-circumferential weld: the mid-circumferential weld and some weld intersections F1-Fn located on the mid-circumferential weld are synchronously scaled with a mapping coefficient η3, and the tail end points D1-Dn are all located on the mid-circumferential weld, and the weld intersections F1-Fn are equidistantly staggered along the circumferential direction; wherein the scaled length l3' of each mid-circumferential weld is η3 times its real length l3; the coordinates of each mid-circumferential weld intersection are η3 times the real coordinates; D1-Dn and F1-Fn together constitute the mid-circumferential weld intersection; Step 5-4, constructing the lower temperate zone weld: starting from the mid-circumferential weld intersection F1-Fn, construct lower temperate zone welds with a length of l'4 along the radial direction, and the tail end points are E1-En respectively; wherein l'4=l4·η4, l4 is the actual length of the lower temperate zone weld; Step 5-5, construct the lower circular weld: scale the lower circular weld with the mapping coefficient η5, and make the tail end points E1-En all located on the lower circular weld, and form the lower circular weld intersection; wherein, the scaled length l5' of each lower circular weld is η5 times its actual length l5; the coordinates of each lower circular weld intersection are η5 times the actual coordinates.

7. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 1, characterized in that: In step 3, in the two-dimensional map of the upper pole belt weld, each line segment intersection point represents the intersection point of the actual weld, represented by letters A1-An; in step 4, in the two-dimensional map of the lower pole belt weld, each line segment intersection point represents the intersection point of the actual weld, represented by letters B1-Bn.

8. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 1, characterized in that: In step 6, the welds are divided into n categories according to the weld length of the spherical tank, and n weld length coefficients [k1, k2, k3, L, k n ], so that the true length of each weld can be saved; among them, the true length of the i-th type weld is l ri The saving method is: ri =k i πR c ; where k i Represents the length coefficient of the i-th type weld, 1≤i≤n; R c is the radius of the spherical tank.

9. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 8, characterized in that: In step 6, n=8, which are the upper / lower polar zone oblique weld, the upper / lower polar zone transverse edge weld, the upper / lower polar zone transverse center weld, the upper / lower polar zone longitudinal weld, the upper / lower circumferential weld, the upper temperate zone weld, the mid-circumferential weld and the lower temperate zone weld; 8 weld length coefficients [k1, k2, k3, L, k8] are set to save the actual lengths of the 8 types of welds.

10. The method for constructing a 2D map of a petrochemical spherical tank for a high-altitude wall-climbing detection robot according to claim 9, characterized in that: k1=0.0645; k2=0.0967; k3=0.0806; k4=0.2546; k5=0.0707; k6=0.2220; k7=0.0978 and k8=0.2779.

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