A multi-layer transfer photogrammetry method and system

Abstract

The present invention provides a multi-layer transfer photogrammetry method and system, the multi-layer transfer photogrammetry method includes setting n cameras C, n-1 first targets T and any second targets U; wherein the camera C i Able to shoot C i+1 , camera C i and Camera C i+1 Able to simultaneously capture the i-th first target T i , camera C i Ability to capture any number of second targets U i , where i∈[1,n‑1], n is a natural number greater than or equal to 2; measure and determine the coordinate vector CP of each of the n cameras C j and the coordinate vectors TP of each of the n-1 first targets T k ; Set m to 1; take m as the serial number, and follow the order of m from 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 The advantages of the present invention are: the measurement distance of photogrammetry is expanded; and the system is easy to expand.

Description

Technical Field

[0001] The present invention relates to the field of engineering monitoring, and in particular to a multi-layer transfer photogrammetry method and system. Background Art

[0002] With the development of infrastructure and industry in recent years, a large number of existing infrastructure structures, such as bridges, tunnels, dams, houses, etc., need real-time status maintenance to extend the service life of infrastructure and reduce the risk of accidents.

[0003] Most existing video measurement technologies rely on single-camera, single-layer photogrammetry systems. These systems are limited in measurement range by the camera's depth of field, typically measuring only scenes within 500 meters. Consequently, existing video measurement systems struggle to maintain accurate measurement accuracy when measuring deformation on large-scale infrastructure, particularly for measuring the displacement and spatial attitude of long linear structures like tunnels, dams, seawalls, and riverbanks.

[0004] In summary, there is a need in the art to provide a multi-layer transfer photogrammetry method and system that can overcome the shortcomings of the prior art. Summary of the Invention

[0005] The present invention provides a multi-layer transfer photogrammetry method and system, which can solve the problems existing in the prior art. The purpose of the present invention is achieved through the following technical solutions.

[0006] One embodiment of the present invention provides a multi-layer transfer photogrammetry method, which includes multiple steps:

[0007] Step 1: Set n cameras C, n-1 first targets T and any second targets U; where camera C i Able to shoot C i+1 , camera C i and Camera C i+1 Able to simultaneously capture the i-th first target T i , camera C i Ability to capture any number of second targets U i , where i∈[1,n-1], n is a natural number greater than or equal to 2;

[0008] Step 2: Measure and determine the coordinate vector CP of each of the n cameras C j and the coordinate vectors TP of the n-1 first targets T k , where j∈[1,n], k∈[1,n-1];

[0009] Step 3: Set m to 1; and

[0010] Step 4: Take m as the serial number, and follow the order from 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 .

[0011] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 4: with m as the serial number, in the order of m from 1 to n-1, in turn according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 The following steps are involved:

[0012] Step 41: Via Camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ;

[0013] Step 42: According to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 ;

[0014] Step 43: Via Camera C m+1 Detection Camera C m+1 The second target U that can be photographed m+1 The relative coordinate vector QR m+1 ;

[0015] Step 44: According to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 ;

[0016] Step 45: Determine whether m is equal to n-1. If yes, the process ends; if no, go to step 46; and

[0017] Step 46: Attach Camera C m+1 Coordinate vector CP m+1 Set as CP' m+1 , the first target T m Coordinate vector TP m Set as TP' m , set m to m+1, and then execute step 41 again.

[0018] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 41: using camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ;

[0019] Step 411: Through Camera C m Detection Camera C m+1 The relative coordinate vector CR' m+1 and the first target T m The current relative coordinate vector TR' m ;

[0020] Step 412: According to the relative coordinate vector CR' m+1 Get Camera C m+1 The current coordinate vector CP' m+1 =MC m+1 *CR' m+1 , where MC m+1 To set the camera C m+1 The coordinate vector from camera C m The mapping matrix MC is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to camera C m and Camera C m+1 Between and Camera C m and the relative distance between the camera C1 during setup; and

[0021] Step 413: According to the relative coordinate vector TR' m Get the first target T m The current coordinate vector TP' m =MT m *TR' m , where MT m To set the first target T m The coordinate vector from camera C m The mapping matrix MT is the mapping matrix of the relative coordinate system to the absolute coordinate system. m According to the first target T mand Camera C m Between and Camera C m The relative distance between it and camera C1 is determined during setup.

[0022] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 42: according to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 It involves several steps:

[0023] Step 421: Calculate the translation error ES m+1 =-(CP' m+1 -CP m+1 )=CP m+1 -CP' m+1 , and camera C m The first target detected T m The displacement Sg1=TP' m -TP m ;

[0024] Step 422: Through Camera C m+1 Detection of the first target T m The current relative coordinate vector TR" m ;

[0025] Step 423: According to the current relative coordinate vector TR" m Get the first target T m The current coordinate vector TP" m =MT' m *TR” m , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between the camera C1 and the camera C1 is determined during setup;

[0026] Step 424: Calculate camera C m+1 The first target detected T m The displacement Sg2 = TP" m -TP m ;as well as

[0027] Step 425: Calculate camera C m+1 The total error E = Sg2 – Sg1, and the rotation error ER m+1 =(E+ES m+1 )*(MT' m ) -1 , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

[0028] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 44: according to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 , where Q m+1 =(QR m+1 -ER m+1 )*MU m+1 -Sg1, where MU m+1 To make the second target U m+1 The coordinate vector from camera C m+1 The mapping matrix MU is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to the second target U m+1 and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

[0029] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 1 further includes setting a third target V, the third target V is set at a coordinate vector T v In a stable position, camera C n The third target V can be photographed.

[0030] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 45: determining whether m is equal to n-1 further includes the following steps:

[0031] Step 451: Determine whether m is equal to n-1. If yes, go to step 462; if no, go to step 46;

[0032] Step 452: Through Camera C n Detect the relative coordinate vector TR of the third target V v ;

[0033] Step 453: According to the translation error ES m+1 , rotation error ER m+1 and the relative coordinate vector TR of the third target V v Get the coordinate vector T' of the third target V v , where T' v =(TR v -ER m+1 )*MV–Sg1, where MV is the coordinate vector of the third target V from the camera C n The mapping matrix MV is a mapping matrix that maps the relative coordinate system to the absolute coordinate system according to the third target V and the camera C n Between and Camera C n The relative distance between the camera C1 and the camera C1 is determined during setup;

[0034] Step 454: Determine T' v Is it equal to T v If “yes”, the process ends; if “no”, go to step 455; and

[0035] Step 455: Calculate S=T' v -T v , the coordinate vector of the second target U detected by each camera is adjusted according to S through the adjustment algorithm, and then the processing ends.

[0036] In the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the camera C1 is set in a stable position.

[0037] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the camera C is capable of identifying and locating the target.

[0038] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the camera C x There is a camera C x-1 Identified target, x∈[2,n].

[0039] One embodiment of the present invention provides a multi-layer transmission photogrammetry system, which includes a reference camera and multiple photogrammetry modules, the photogrammetry module including a secondary camera, a first target and multiple second targets, the multiple photogrammetry modules are arranged in sequence and numbered 2, 3...n in sequence, the secondary camera of the photogrammetry module can photograph and locate the first target and multiple second targets in the same photogrammetry module, the camera of the photogrammetry module numbered i can also photograph and locate the camera and the first target in the photogrammetry module numbered i+1, i∈[2,n-1], the reference camera can photograph and locate the camera and the first target in the photogrammetry module numbered 2, and the reference camera is set in a stable position.

[0040] According to the multi-layer transfer photogrammetry system provided by one embodiment of the present invention, the multi-layer transfer photogrammetry system further includes a third target, which is set in a stable position and the secondary camera of the photogrammetry module numbered n can capture the third target.

[0041] The advantages of the multi-layer transfer photogrammetry method according to the embodiment of the present invention are: it expands the measurement distance while ensuring the measurement accuracy of video detection; it frees photogrammetry from being limited by the depth of field limitation of a single camera device, allowing photogrammetry to be used in scenarios where there are no stable measurement points suitable for setting up a camera device around the object to be detected, while also reducing the requirements for the depth of field performance of a single camera device and reducing costs; it improves the adaptability of photogrammetry to the detection of large and long measurement targets, ensuring the measurement accuracy of large measurement targets; and it can be expanded by adding photogrammetry modules, making system expansion simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments of the present invention with reference to the accompanying drawings.

[0043] Figure 1 A flowchart of a multi-layer transfer photogrammetry method according to one embodiment of the present invention is shown.

[0044] Figure 2 Shown as Figure 1 FIG. 4 is a flow chart of step 4 of the photogrammetry method for multi-layer transfer according to one embodiment of the present invention.

[0045] Figure 3 Shown as Figure 1 FIG. 4 is a flow chart showing step 41 of a multi-layer transfer photogrammetry method according to an embodiment of the present invention.

[0046] Figure 4 Shown as Figure 1FIG. 4 is a flow chart showing step 42 of a multi-layer transfer photogrammetry method according to an embodiment of the present invention.

[0047] Figure 5 Shown as Figure 1 FIG. 4 is a flow chart showing step 45 of a multi-layer transfer photogrammetry method according to an embodiment of the present invention.

[0048] Figure 6 A schematic diagram of a multi-layer transfer photogrammetry system according to one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0049] The specific embodiments of the present invention are described below in conjunction with the accompanying drawings and examples. Through the contents of this specification, those skilled in the art can clearly and completely understand the technical solutions, technical problems solved, and technical effects produced by the present invention. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the present invention. In addition, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0050] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of the specification are only used to match the contents recorded in the specification for technical personnel in this field to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0051] References such as "first", "second", "the" and the like do not indicate a quantitative limitation and may indicate the singular or plural. The terms "include", "comprising", "having" and any variations thereof involved in the present invention are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. Similar words such as "connect", "connected", "coupled" and the like involved in the present invention are not limited to physical or mechanical connections, but may also include direct or indirect electrical connections.

[0052] Figure 1 FIG. 1 is a flow chart showing a photogrammetry method for multi-layer transfer according to an embodiment of the present invention. Figure 1 As shown, the multi-layer transfer photogrammetry method includes several steps:

[0053] Step 1: Set n cameras C, n-1 first targets T and any second targets U; where camera Ci Able to shoot C i+1 , camera C i and Camera C i+1 Able to simultaneously capture the i-th first target T i , camera C i Ability to capture any number of second targets U i , where i∈[1,n-1], n is a natural number greater than or equal to 2;

[0054] Step 2: Measure and determine the coordinate vector CP of each of the n cameras C j and the coordinate vectors TP of the n-1 first targets T k , where j∈[1,n], k∈[1,n-1];

[0055] Step 3: Set m to 1; and

[0056] Step 4: Take m as the serial number, and follow the order from 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 .

[0057] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the coordinate vectors CP of the cameras C are j and the first target T's respective coordinate vectors TP k They respectively refer to the coordinate vectors of the camera C and the first target T in a preset vertical plane, that is, the coordinate vectors of the camera C and the first target T in the absolute coordinate system composed of the horizontal and vertical directions.

[0058] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, camera C1 is positioned in a stable position. A coordinate system is established with the lower left corner of the image captured by camera C1 as the origin, and the multi-layer transfer photogrammetry method uses this coordinate system as the absolute coordinate system (or reference coordinate system). Coordinate systems established with the lower left corner of the image captured by cameras other than C1 as the origin are all relative coordinate systems. In the embodiments, vectors described as coordinate vectors refer to coordinate vectors in the absolute coordinate system, while vectors described as relative coordinate vectors refer to coordinate vectors in the relative coordinate system.

[0059] Since the cameras other than C1 are not set in a stable position, they will be displaced and thus cause measurement errors. Such errors include translation errors due to camera displacement and rotation errors due to camera rotation.

[0060] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the camera C is capable of identifying and locating the target.

[0061] Figure 2 Shown as Figure 1 Flowchart of step 4 of the photogrammetry method of multi-layer transfer according to one embodiment of the present invention. Figure 2 As shown, step 4: Step 4: Take m as the serial number, and follow the order from m 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 The following steps are involved:

[0062] Step 41: Via Camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ;

[0063] Step 42: According to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 ;

[0064] Step 43: Via Camera C m+1 Detection Camera C m+1 The second target U that can be photographed m+1 The relative coordinate vector QR m+1 ;

[0065] Step 44: According to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 ;

[0066] Step 45: Determine whether m is equal to n-1. If yes, the process ends; if no, go to step 46; and

[0067] Step 46: Attach Camera C m+1 Coordinate vector CPm+1 Set as CP' m+1 , the first target T m Coordinate vector TP m Set as TP' m , set m to m+1, and then execute step 41 again.

[0068] Figure 3 Shown as Figure 1 41 of the photogrammetry method for multi-layer transfer according to one embodiment of the present invention. Figure 3 As shown, step 41: through camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ;

[0069] Step 411: Through Camera C m Detection Camera C m+1 The relative coordinate vector CR' m+1 and the first target T m The current relative coordinate vector TR' m ;

[0070] Step 412: According to the relative coordinate vector CR' m+1 Get Camera C m+1 The current coordinate vector CP' m+1 =MC m+1 *CR' m+1 , where MC m+1 To set the camera C m+1 The coordinate vector from camera C m The mapping matrix MC is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to camera C m and Camera C m+1 Between and Camera C m and the relative distance between the camera C1 during setup; and

[0071] Step 413: According to the relative coordinate vector TR' m Get the first target T m The current coordinate vector TP' m =MT m *TR' m , where MT m To set the first target T m The coordinate vector from camera C m The mapping matrix MT is the mapping matrix of the relative coordinate system to the absolute coordinate system. m According to the first target Tm and Camera C m Between and Camera C m The relative distance between it and camera C1 is determined during setup.

[0072] Figure 4 Shown as Figure 1 42 of the multi-layer transfer photogrammetry method according to one embodiment of the present invention. Figure 4 As shown, step 42: according to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 It involves several steps:

[0073] Step 421: Calculate the translation error ES m+1 =-(CP' m+1 -CP m+1 )=CP m+1 -CP' m+1 , and camera C m The first target detected T m The displacement Sg1=TP' m -TP m ;

[0074] Step 422: Through Camera C m+1 Detection of the first target T m The current relative coordinate vector TR" m ;

[0075] Step 423: According to the current relative coordinate vector TR" m Get the first target T m The current coordinate vector TP" m =MT' m *TR” m , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between the camera C1 and the camera C1 is determined during setup;

[0076] Step 424: Calculate camera C m+1The first target detected T m The displacement Sg2 = TP" m -TP m ;as well as

[0077] Step 425: Calculate camera C m+1 The total error E = Sg2 – Sg1, and the rotation error ER m+1 =(E+ES m+1 )*(MT' m ) -1 , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

[0078] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 44: according to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 , where Q m+1 =(QR m+1 -ER m+1 )*MU m+1 -Sg1, where MU m+1 To make the second target U m+1 The coordinate vector from camera C m+1 The mapping matrix MU is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to the second target U m+1 and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

[0079] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, step 1 further includes setting a third target V, the third target V is set at a coordinate vector T v In a stable position, camera C n The third target V can be photographed. The position of the third target V does not change, so the third target V can be used to correct the errors generated in the calculation of the multi-layer transfer photogrammetry method.

[0080] Figure 5 Shown as Figure 1 45 is a flow chart of a multi-layer transfer photogrammetry method according to an embodiment of the present invention. Figure 5 As shown, step 45: determining whether m is equal to n-1 further includes the following steps:

[0081] Step 451: Determine whether m is equal to n-1. If yes, go to step 462; if no, go to step 46;

[0082] Step 452: Through Camera C n Detect the relative coordinate vector TR of the third target V v ;

[0083] Step 453: According to the translation error ES m+1 , rotation error ER m+1 and the relative coordinate vector TR of the third target V v Get the coordinate vector T' of the third target V v , where T' v =(TR v -ER m+1 )*MV–Sg1, where MV is the coordinate vector of the third target V from the camera C n The mapping matrix MV is a mapping matrix that maps the relative coordinate system to the absolute coordinate system according to the third target V and the camera C n Between and Camera C n The relative distance between the camera C1 and the camera C1 is determined during setup;

[0084] Step 454: Determine T' v Is it equal to T v If “yes”, the process ends; if “no”, go to step 455; and

[0085] Step 455: Calculate S=T' v -T v , the coordinate vector of the second target U detected by each camera is adjusted according to S through the adjustment algorithm, thereby reducing the measurement error of each camera and improving the accuracy, and then the processing ends.

[0086] According to the multi-layer transfer photogrammetry method provided by one embodiment of the present invention, the camera C x There is a camera C x-1 Identified target, x∈[2,n].

[0087] Figure 6 FIG. 1 shows a schematic diagram of a multi-layer transfer photogrammetry system according to one embodiment of the present invention. Figure 6As shown, the multi-layer transfer photogrammetry system includes a reference camera C1 and a plurality of photogrammetry modules M. The photogrammetry module M includes a secondary camera, a first target and a plurality of second targets. The plurality of photogrammetry modules M are arranged in sequence and numbered 2, 3...n. The photogrammetry module M numbered i includes the secondary camera C1, a first target and a plurality of second targets. i , the first target T i-1 , and the second target U i , camera measurement module M i Secondary camera C i Capable of capturing and positioning the first target T in the same camera measurement module i-1 and multiple second targets U i , the secondary camera C of the camera measurement module M numbered i i It is also possible to capture and locate the secondary camera C in the camera measurement module M numbered i+1 i+1 and the first target T i , i∈[2,n-1], the reference camera C1 can capture and locate the secondary camera C2 and the first target T1 in the camera measurement module M numbered 2, and the reference camera is set in a stable position.

[0088] According to the multi-layer transfer photogrammetry system provided by the above-mentioned embodiment of the present invention, the multi-layer transfer photogrammetry system adopts the multi-layer transfer photogrammetry method provided by the above-mentioned embodiment to obtain the displacement of the second target U that each camera C can capture.

[0089] According to the multi-layer transfer photogrammetry system provided by one embodiment of the present invention, the multi-layer transfer photogrammetry system can be expanded by sequentially adding more photogrammetry modules M after the photogrammetry module M numbered n.

[0090] According to the multi-layer transfer photogrammetry system provided by one embodiment of the present invention, the multi-layer transfer photogrammetry system further includes a third target V, which is set in a stable position, and the secondary camera C of the photogrammetry module M numbered n n The third target V can be photographed.

[0091] The advantages of the multi-layer transfer photogrammetry method according to the embodiment of the present invention are: it expands the measurement distance while ensuring the measurement accuracy of video detection; it frees photogrammetry from being limited by the depth of field limitation of a single camera device, allowing photogrammetry to be used in scenarios where there are no stable measurement points suitable for setting up a camera device around the object to be detected, while also reducing the requirements for the depth of field performance of a single camera device and reducing costs; it improves the adaptability of photogrammetry to the detection of large and long measurement targets, ensuring the measurement accuracy of large measurement targets; and it can be expanded by adding photogrammetry modules, making system expansion simple.

[0092] Although the present invention has been described and illustrated with reference to specific embodiments of the present invention, these descriptions and illustrations are not intended to limit the present invention. It will be clearly understood by those skilled in the art that various changes may be made and equivalent elements may be substituted within the embodiments without departing from the scope of protection of the present invention as defined by the claims. Due to variables in the manufacturing process, etc., there may be differences between the technical reproduction of the present invention and the actual device. There may be other embodiments of the present invention that are not specifically described. The description and illustrations should be regarded as illustrative, not restrictive, and modifications may be made according to the purpose and spirit of the present invention, all of which are within the scope of protection of the claims. Although the methods disclosed herein have been described with reference to specific operations performed in a specific order, it should be understood that these operations can be recombined, subdivided or arranged to form equivalent methods without departing from the teachings of the present invention. Therefore, unless specifically indicated herein, the order and grouping of operations do not limit the present invention.

Claims

1. A multi-layer transfer photogrammetry method, characterized in that: It involves several steps: Step 1: Set n cameras C, n-1 first targets T and any second targets U; where camera C i Able to shoot C i+1 , camera C i and Camera C i+1 Able to simultaneously capture the i-th first target T i , camera C i Ability to capture any number of second targets U i , where i∈[1,n-1], n is a natural number greater than or equal to 2; Step 2: Measure and determine the coordinate vector CP of each of the n cameras C j and the coordinate vectors TP of the n-1 first targets T k , where j∈[1,n], k∈[1,n-1]; Step 3: Set m to 1; as well as Step 4: Take m as the serial number, and follow the order from 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 .

2. The multi-layer transfer photogrammetry method according to claim 1, characterized in that: Step 4: Take m as the serial number, and follow the order from 1 to n-1, according to CP m 、CP m+1 and TP m Get Camera C m+1 Each second target U that can be photographed m+1 The displacement Q m+1 The following steps are involved: Step 41: Via Camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ; Step 42: According to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 ; Step 43: Via Camera C m+1 Detection Camera C m+1 The second target U that can be photographed m+1 The relative coordinate vector QR m+1 ; step 44: According to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 ; Step 45: Determine whether m is equal to n-1. If yes, the process ends; if no, go to step 46. as well as Step 46: Attach Camera C m+1 Coordinate vector CP m+1 Set as CP' m+1 , the first target T m Coordinate vector TP m Set as TP' m , set m to m+1, and then execute step 41 again.

3. The multi-layer transfer photogrammetry method according to claim 2, characterized in that: Step 41: Via Camera C m Detection Camera C m+1 The current coordinate vector CP' m+1 and the first target T m The current coordinate vector TP' m ; Step 411: Through Camera C m Detection Camera C m+1 The relative coordinate vector CR' m+1 and the first target T m The current relative coordinate vector TR' m ; Step 412: According to the relative coordinate vector CR' m+1 Get Camera C m+1 The current coordinate vector CP' m+1 =MC m+1 *CR' m+1 , where MC m+1 To set the camera C m+1 The coordinate vector from camera C m The mapping matrix MC is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to camera C m and Camera C m+1 Between and Camera C m The relative distance between the camera C1 and the camera C1 is determined during setup; as well as Step 413: According to the relative coordinate vector TR' m Get the first target T m The current coordinate vector TP' m =MT m *TR' m , where MT m To set the first target T m The coordinate vector from camera C m The mapping matrix MT is the mapping matrix of the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m Between and Camera C m The relative distance between it and camera C1 is determined during setup.

4. The multi-layer transfer photogrammetry method according to claim 3, characterized in that: Step 42: According to the coordinate vector CP m 、CP m+1 TP m , CP' m+1 TP' m Computational Camera C m+1 The translation error ES m+1 and rotation error ER m+1 It involves several steps: Step 421: Calculate the translation error ES m+1 =-(CP' m+1 -CP m+1 )=CP m+1 -CP' m+1 , and camera C m The first target detected T m The displacement Sg1=TP' m -TP m ; Step 422: Through Camera C m+1 Detection of the first target T m The current relative coordinate vector TR" m ; Step 423: According to the current relative coordinate vector TR" m Get the first target T m The current coordinate vector TP" m =MT' m *TR” m , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between the camera C1 and the camera C1 is determined during setup; Step 424: Calculate camera C m+1 The first target detected T m The displacement Sg2 = TP" m -TP m ; as well as Step 425: Calculate camera C m+1 The total error E = Sg2 – Sg1, and the rotation error ER m+1 =(E+ES m+1 )*(MT' m ) -1 , where MT' m To set the first target T m The coordinate vector from camera C m+1 The mapping matrix MT' is the mapping matrix from the relative coordinate system to the absolute coordinate system. m According to the first target T m and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

5. The multi-layer transfer photogrammetry method according to claim 4, characterized in that: Step 44: According to the translation error ES m+1 , rotation error ER m+1 and the second target U m+1 The relative coordinate vector QR m+1 Get the second target U m+1 The coordinate vector Q m+1 , where Q m+1 =(QR m+1 -ER m+1 )*MU m+1 -Sg1, where MU m+1 To make the second target U m+1 The coordinate vector from camera C m+1 The mapping matrix MU is the mapping matrix from the relative coordinate system to the absolute coordinate system. m+1 According to the second target U m+1 and Camera C m+1 Between and Camera C m+1 The relative distance between it and camera C1 is determined during setup.

6. The multi-layer transfer photogrammetry method according to claim 5, characterized in that: Step 1 also includes setting a third target V, which is set at a coordinate vector T v In a stable position, camera C n The third target V can be photographed.

7. The multi-layer transfer photogrammetry method according to claim 6, characterized in that: Step 45: Determining whether m is equal to n-1 further includes the following steps: Step 451: Determine whether m is equal to n-1. If yes, go to step 462; if no, go to step 46; Step 452: Through Camera C n Detect the relative coordinate vector TR of the third target V v ; Step 453: According to the translation error ES m+1 , rotation error ER m+1 and the relative coordinate vector TR of the third target V v Get the coordinate vector T' of the third target V v , where T' v =(TR v -ER m+1 )*MV–Sg1, where MV is the coordinate vector of the third target V from the camera C n The mapping matrix MV is a mapping matrix that maps the relative coordinate system to the absolute coordinate system according to the third target V and the camera C n Between and Camera C n The relative distance between the camera C1 and the camera C1 is determined during setup; Step 454: Determine T' v Is it equal to T v If "yes", the process ends; if "no", go to step 455; as well as Step 455: Calculate S=T' v -T v , the coordinate vector of the second target U detected by each camera is adjusted according to S through the adjustment algorithm, and then the processing ends.

8. The multi-layer transfer photogrammetry method according to any one of claims 1 to 7, characterized in that: The camera C1 is set in a stable position.

9. The multi-layer transfer photogrammetry method according to claim 1, characterized in that: Camera C is able to identify and locate the target.

10. The multi-layer transfer photogrammetry method according to claim 1, characterized in that: Camera C x There is a camera C x-1 Identified target, x∈[2,n].

11. A multi-layer transfer photogrammetry system, characterized in that: It includes a reference camera and multiple photogrammetry modules. The photogrammetry module includes a secondary camera, a first target and multiple second targets. The multiple photogrammetry modules are arranged in sequence and numbered 2, 3...n in sequence. The secondary camera of the photogrammetry module can shoot and locate the first target and multiple second targets in the same photogrammetry module. The camera of the photogrammetry module numbered i can also shoot and locate the camera and the first target in the photogrammetry module numbered i+1, i∈[2,n-1]. The reference camera can shoot and locate the camera and the first target in the photogrammetry module numbered 2. The reference camera is set in a stable position.

12. The multi-layer transfer photogrammetry system according to claim 11, characterized in that The multi-layer transfer photogrammetry system further includes a third target, which is arranged at a stable position. The secondary camera of the photogrammetry module numbered n can photograph the third target.

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