MEMS inertial navigation-based house wall surface contour measurement method, equipment and medium

Abstract

The invention discloses a house wall profile measurement method and device based on MEMS inertial navigation, and a medium, and the method specifically comprises the following steps: S1, installing the MEMS inertial navigation on the wall of a building or house to be measured, and obtaining the coordinate data of a measurement point and a corresponding quaternion; s2, according to the coordinate data and quaternion of the measuring point, judging whether the measuring point is a wall surface point, and if yes, recording the wall surface point and a corresponding wall surface; s3, calculating wall corner points according to the identified wall surface points; and S4, sequentially connecting the wall surface points and the wall corner points so as to obtain the wall surface contour of the to-be-measured building or house.

Description

Technical Field

[0001] The present invention relates to the field of measurement technology, and in particular to a method, equipment and medium for measuring the profile of a house wall based on MEMS inertial navigation. Background Art

[0002] In the production of small-scale topographic maps, the measurement of buildings, a characteristic element, mainly relies on technical means such as total stations, tilt RTK and aerial image stereo measurement. In the early days of house measurement, total stations were mainly used to measure the corner lines and base positions of buildings. The measurement accuracy was high, but there were problems such as complex operation, high labor costs, and long operation time.

[0003] With the rapid development of GNSS, tilt RTK equipment with additional inertial navigation has been widely used in the fields of house measurement, cadastral surveying and mapping. Tilt RTK is simple and convenient to operate, and can be measured at the point, which greatly speeds up the efficiency of field surveying. However, in areas such as mountainous areas and urban canyons where satellite signals are denied, tilt RTK cannot be used. At the same time, with the popularization of drones, it is extremely advantageous to use drones for large-scale aerial surveys of 1:500. For buildings, it is very convenient to obtain the coordinates of the wall by using oblique images and multi-piece forward intersection. However, since there is often occlusion at the base of the wall, it is difficult to match the same-name image points, so there are limitations in its application. Summary of the invention

[0004] In view of the problem that contour measurement in the prior art is time-consuming and of low precision, the present invention proposes a house wall contour measurement method, device, and medium based on MEMS inertial navigation.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for measuring the profile of a house wall based on MEMS inertial navigation comprises the following steps:

[0007] S1: Install the MEMS inertial navigation system on the wall of the building or house to be measured, and obtain the coordinate data of the measurement point and the corresponding quaternion;

[0008] S2: judging whether the measuring point is a wall point according to the coordinate data and quaternion of the measuring point, if so, recording the wall point and the corresponding wall, if not, recording it as a non-wall point;

[0009] S3: Calculate the corner points based on the identified wall points;

[0010] S4: Connect each wall point and corner point in sequence to obtain the wall outline of the building or house to be measured.

[0011] Preferably, the S2 includes:

[0012] S2-1: Calculate the rotation matrix from b system to n system based on quaternion

[0013] S2-2: Based on the rotation matrix Calculate the acceleration unit vector in the n system

[0014]

[0015] In formula (1), represents the unit acceleration vector of the kth wall point in the i-th wall in the n-frame; Represents the rotation matrix from b system to n system; represents the unit acceleration vector of the kth wall point on the ith wall in the b system;

[0016] S2-3: If If the modulus of the sum of the x-axis and y-axis components is greater than or equal to the threshold, it means that the MEMS inertial navigation is located on the wall, and the coordinates of the measurement point are recorded. is the wall point and the corresponding wall i.

[0017] Preferably, the S2 further includes:

[0018] S2-4: When measuring the i+1th wall, the coordinate data of the first measuring point is Its acceleration unit vector in the n system is Calculate the acceleration unit vector of the last measurement point j on the i-th wall The acceleration unit vector of the first measurement point on the i+1th wall If the angle is 0°, then the first measurement point of the i+1th wall and the last measurement point j of the i-th wall are judged to be the same wall; if the angle is not 0°, then the first measurement point of the i+1th wall and the last measurement point j of the i-th wall do not belong to the same wall.

[0019] Preferably, in S3, the corner point is calculated as follows:

[0020] S3-1: When there is only one wall point on the i-th wall, its coordinates are The unit of acceleration in the n system is The coordinates of the first point on the i+1th wall are Its acceleration unit vector in the n system is

[0021] According to a point on the straight line and its normal vector, the coordinates of another point on the i-th wall are The coordinates of another point on the i+1th wall are The calculation formula is:

[0022]

[0023] In formula (2), is the straight line L represented by the i-th wall i The normal vector, z x express The x-axis component, z y express The y-axis component of is the first point on the i-th wall, for The coordinates of the point; is the second point on the i-th wall, for The coordinates of the point;

[0024] Then, the i-th wall and The connecting line forms the first wall plane position line L corresponding to the i-th wall i , and on the i+1th wall and The connecting line forms the second wall plane position line L corresponding to the i+1th wall i+1 , then the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point

[0025] Preferably, in S3, the corner point is calculated as follows:

[0026] S3-2: When there are two or more wall points on the i-th wall, the least squares method is used to fit the first wall plane position line L according to all wall points when calculating the wall straight line. i :

[0027] Assume that there are m points on the wall, m ≥ 2, and the mth point The coordinates of Will Substituting into the equation of the line we get Right now

[0028]

[0029] In formula (3), b 1 、b 2 represents the coefficient;

[0030] Similarly, the first m-1 points are substituted into the line equation and combined into a matrix form:

[0031]

[0032] make According to the least squares principle, we can solve

[0033]

[0034] Then we can get the straight line L i The equation y = b 1 ·x+b 2 ;

[0035] Similarly, we get the second wall plane position line L corresponding to the i+1th wall i+1 ;

[0036] Finally, the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point, and its coordinates are

[0037] Preferably, the method further includes S5:

[0038] Obtain inertial navigation coordinates corresponding to a first distance and a second distance outside a building or a house to be measured, and obtain rotation parameters and translation parameters of the absolute coordinates and the inertial navigation coordinates according to a first absolute coordinate of the first distance, the first inertial navigation coordinates and the second absolute coordinate of the second distance, and the second inertial navigation coordinates;

[0039] The coordinates of the wall points and corner points are converted to the absolute coordinate system according to the rotation parameters and translation parameters, and then the wall points and corner points in the absolute coordinate system are connected in sequence to complete the real estate surveying and mapping.

[0040] The present invention also provides a device, including a memory and a processor; the memory stores a computer program that can be run on the processor, and the processor implements a house wall profile measurement method based on MEMS inertial navigation when executing the computer program.

[0041] The present invention also provides a readable medium, on which a computer program is stored; when the computer program is executed by a processor, a method for measuring the contour of a house wall based on MEMS inertial navigation is implemented.

[0042] In summary, due to the adoption of the above technical solution, compared with the prior art, the present invention has at least the following beneficial effects:

[0043] The present invention uses MEMS inertial navigation to measure the contour of the house wall, making full use of the plumb bob of the wall and the all-weather, autonomous, compact and high-precision characteristics of the MEMS inertial navigation. In the measurement of the building wall, especially the house, it only needs to be placed on each wall in sequence, and a measurement point is obtained for each. After the measurement is completed, a plan view of the house wall contour can be generated. This method can be effectively applied to various satellite-denied environments and scenes that cannot be reached by traditional house measurement methods, and can also quickly and conveniently perform real estate mapping; at the same time, the present invention can also be applied to interior decoration, and quickly measure and generate indoor floor plans. Therefore, the present invention has broad application prospects in the fields of real estate mapping and interior decoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The figure is a schematic diagram of a method for measuring a house wall profile based on MEMS inertial navigation according to an exemplary embodiment of the present invention.

[0045] Figure 2 FIG. 4 is a schematic diagram of a MEMS inertial navigation installation according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0047] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] like Figure 1 As shown, the present invention provides a method for measuring the profile of a house wall based on MEMS inertial navigation, comprising the following steps:

[0049] S1: Figure 2 As shown, the MEMS (Micro Electro Mechanical System) inertial navigation system is placed in sequence and close to the wall (L3, L4, L1) of the building or house to be measured in such a way that the Z axis of the carrier coordinate system is perpendicular to the wall, and the coordinate data of the measuring point and its quaternion are obtained.

[0050] In this embodiment, the measurement of MEMS inertial navigation is continuous, so points on the wall and points on the ground (non-wall points) will be collected, but the coordinates and quaternions of all measurement points will be recorded. Assume that the MEMS inertial navigation is placed with the Z axis (or X or Y axis) of the carrier coordinate system perpendicular to the wall and close to the i-th wall, collect the first coordinate data, and obtain the coordinates in the navigation coordinate system (n system) And its quaternion Represents the first coordinate data of the i-th wall in the n-system; Represents the quaternion corresponding to the first coordinate data of the i-th wall in the n-frame.

[0051] In this embodiment, the MEMS inertial navigation system is placed at any position on the wall, not at the corners, and the corner points are calculated. A wall can have only one point or multiple points, depending on how many times the surveyor wants to place it on the wall, and one point is measured each time it is placed. There is no regulation on the distribution of the measurement points, which can be evenly distributed in large quantities or sparsely distributed. The measurement point represents the three-dimensional coordinates of the MEMS inertial navigation system. The z-axis coordinate value is not involved in the calculation because the wall contour is a plane straight line.

[0052] S2: According to the coordinate data and quaternion of the measuring point, determine whether the measuring point is a wall point. If so, record the wall point and the corresponding wall. Otherwise, record it as a non-wall point and do not participate in subsequent calculations.

[0053] In this embodiment, the method for determining whether the measuring point is a wall point is:

[0054] According to quaternion Calculate the rotation matrix from b to n The formula is as follows:

[0055]

[0056] Among them, q 0 ,q 1 ,q 2 ,q 3 is a quaternion parameter;

[0057] When the MEMS inertial navigation system is close to the wall (taking the Z axis as an example), its acceleration unit vector a in the b system is b =

[001] , using the rotation matrix Calculate the unit vector of its acceleration in the n system at this time

[0058]

[0059] In formula (1), represents the unit acceleration vector of the kth wall point in the i-th wall in the n-frame; Represents the second rotation matrix from b system to n system; It represents the unit acceleration vector of the kth point on the ith wall in the b system.

[0060] Assuming that all walls do not deform and remain plumb, then The z-axis component is close to 0, and the modulus of the x- and y-axis components is close to 1. Based on this, the modulus thresholds of the x- and y-axis components are set to 0.9 (the thresholds are adjustable); if If the modulus of the sum of the x-axis and y-axis components is greater than or equal to the threshold, it means that the MEMS inertial navigation is located on the wall, and the coordinates of the measurement point are recorded. is the wall point and the corresponding wall i.

[0061] In this embodiment, when measuring the i+1th wall, the coordinate data of the first measurement point is Its z acceleration unit vector in the n frame is Calculate the acceleration unit vector of the last measurement point j on the i-th wall The acceleration unit vector of the first measurement point on the i+1th wall If the angle is 0° (there may be a certain error), it is judged that the first measurement point of the i+1th wall and the last measurement point j of the i-th wall are the same wall, that is, the first measurement point of the i+1th wall is the j+1th measurement point; if the angle is not 0°, it is judged that the first measurement point of the i+1th wall and the last measurement point j of the i-th wall do not belong to the same wall, that is, the first measurement point of the i+1th wall is the first point on the new wall.

[0062] The surveyor knows which wall is being measured, but the MEMS inertial navigation program does not know it. It is named i+1 here for easy distinction. In fact, in the program, the index of each inertial navigation measurement point is accumulated in sequence. Only when the program determines whether it is on the wall and whether it is the current wall, will the properties of this point be set, including which wall it is on and which point it is. By default, the wall where the first point on the wall is located is the first wall, so it is possible to determine whether it is a new wall at any time based on the angle between the next measurement point and the previous measurement point, and set the properties of the measurement point.

[0063] S3: Calculate the two-dimensional coordinates of the corner points based on the identified wall points.

[0064] S3-1: Assume that among the identified wall points, there is only one point located on the i-th wall, and its coordinates are Its acceleration unit vector in the n system is The coordinates of the first point on the i+1th wall are Its acceleration unit vector in the n system is

[0065] According to a point on the straight line and its normal vector, the coordinates of another point on the i-th wall are The coordinates of another point on the i+1th wall are The calculation formula is:

[0066]

[0067] In formula (2), is the straight line L represented by the i-th wall i The normal vector, z x express The x-axis component, z y express The y-axis component of is the first point on the i-th wall, for The coordinates of the point; is the second point on the i-th wall, for The coordinates of the point;

[0068] Then, the i-th wall and The corresponding point connection line can form the first wall plane position line L corresponding to the i-th wall i , and on the i+1th wall and The corresponding point connection line can form the second wall plane position line L corresponding to the i+1th wall i+1 , then the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point, and its coordinates are

[0069] S3-2: Assume that among the identified wall points, there are two or more wall points located on the i-th wall. When calculating the wall straight line, the least squares method is used to fit the most suitable straight line according to all the wall points as the first wall plane position line L i Multiple points can only fit a straight line with the smallest error, so when there are more than two points, it is necessary to recalculate the equation of the wall line, which also requires recalculating the corner points, but not the coordinates of the wall points.

[0070] Assume that there are m points on the wall, m ≥ 2, and the mth point The coordinates of Will Substituting into the equation of the line we get Right now

[0071]

[0072] In formula (3), b 1 、b2 represents the coefficient;

[0073] Similarly, the first m-1 points are substituted into the line equation and combined into a matrix form:

[0074]

[0075] make According to the least squares principle, we can solve

[0076]

[0077] Then we can get the straight line L i The equation y = b 1 ·x+b 2 .

[0078] Similarly, we can get the second wall plane position line L corresponding to the i+1th wall i+1 .

[0079] Finally, the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point, and its coordinates are

[0080] S4: For the building or house to be measured, connect the wall points and corner points in sequence to obtain the outline of the wall.

[0081] S5: When it is necessary to conduct real estate surveying for the building or house to be measured, at a first distance and a second distance outside the building or house to be measured (for example, the distance is 10 meters, but the direction is different), the absolute coordinates of the first distance and the second distance and the corresponding inertial navigation coordinates are obtained, and the rotation parameters and translation parameters of the absolute coordinates and the inertial navigation coordinates are obtained according to the first absolute coordinate of the first distance, the first inertial navigation coordinate and the second absolute coordinate of the second distance, and the second inertial navigation coordinate; then the coordinates of the wall points and the corner points are converted to the CGCS2000 coordinate system, thereby completing the real estate surveying.

[0082] In this embodiment, the absolute coordinate point refers to a CGCS2000 coordinate point or a coordinate point in another independent coordinate system, which can be obtained through RTK measurement or through existing control points.

[0083] The present invention uses MEMS inertial navigation to measure the contour of the house wall, making full use of the plumb bob of the wall and the all-weather, autonomous, compact and high-precision characteristics of the MEMS inertial navigation. In the measurement of the building wall, especially the house, it only needs to be placed on each wall in sequence, and a measurement point is obtained for each. After the measurement is completed, a plan view of the house wall contour can be generated. This method can be effectively applied to various satellite-denied environments and scenes that cannot be reached by traditional house measurement methods, and can also quickly and conveniently perform real estate mapping; at the same time, the present invention can also be applied to interior decoration, and quickly measure and generate indoor floor plans. Therefore, the present invention has broad application prospects in the fields of real estate mapping and interior decoration.

[0084] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for measuring the contour of a house wall based on MEMS inertial navigation is implemented.

[0085] The present application also provides a computer-readable medium, on which is stored a method for measuring the contour of a house wall based on MEMS inertial navigation as described in an embodiment.

[0086] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, device or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0087] The computer readable medium may be included in the system described in the above embodiment; or it may exist independently without being assembled into the system. The above computer readable medium carries one or more programs. When the above one or more programs are executed by a system, the system implements a method for measuring the contour of a house wall based on MEMS inertial navigation.

[0088] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A method for measuring the profile of a house wall based on MEMS inertial navigation, characterized in that: The specific steps include: S1: Install the MEMS inertial navigation system on the wall of the building or house to be measured, and obtain the coordinate data of the measurement point and the corresponding quaternion; S2: judging whether the measuring point is a wall point according to the coordinate data and quaternion of the measuring point, if so, recording the wall point and the corresponding wall, if not, recording it as a non-wall point; S3: Calculate the corner points based on the identified wall points; S4: Connect each wall point and corner point in sequence to obtain the wall outline of the building or house to be measured.

2. A method for measuring the profile of a house wall based on MEMS inertial navigation as claimed in claim 1, characterized in that: The S2 includes: S2-1: Calculate the rotation matrix from b system to n system based on quaternion S2-2: Based on the rotation matrix Calculate the acceleration unit vector in the n system In formula (1), represents the unit acceleration vector of the kth wall point in the i-th wall in the n-frame; Represents the rotation matrix from b system to n system; represents the unit acceleration vector of the kth wall point on the ith wall in the b system; S2-3: If If the modulus of the sum of the x-axis and y-axis components is greater than or equal to the threshold, it means that the MEMS inertial navigation is located on the wall, and the coordinates of the measurement point are recorded. is the wall point and the corresponding wall i.

3. A method for measuring the profile of a house wall based on MEMS inertial navigation as claimed in claim 2, characterized in that: The S2 further includes: S2-4: When measuring the i+1th wall, the coordinate data of the first measuring point is Its acceleration unit vector in the n system is Calculate the acceleration unit vector of the last measurement point j on the i-th wall The acceleration unit vector of the first measurement point on the i+1th wall If the angle is 0°, then the first measurement point of the i+1th wall and the last measurement point j of the i-th wall are judged to be the same wall; if the angle is not 0°, then the first measurement point of the i+1th wall and the last measurement point j of the i-th wall do not belong to the same wall.

4. A method for measuring the profile of a house wall based on MEMS inertial navigation as claimed in claim 1, characterized in that: In S3, the corner point is calculated as follows: S3-1: When there is only one wall point on the i-th wall, its coordinates are The unit of acceleration in the n system is The coordinates of the first point on the i+1th wall are Its acceleration unit vector in the n system is According to a point on the straight line and its normal vector, the coordinates of another point on the i-th wall are The coordinates of another point on the i+1th wall are The calculation formula is: In formula (2), is the straight line L represented by the i-th wall i The normal vector, z x express The x-axis component, z y express The y-axis component of is the first point on the i-th wall, for The coordinates of the point; is the second point on the i-th wall, for The coordinates of the point; Then, the i-th wall and The connecting line forms the first wall plane position line L corresponding to the i-th wall i , and on the i+1th wall and The connecting line forms the second wall plane position line L corresponding to the i+1th wall i+1 , then the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point 5. A method for measuring the profile of a house wall based on MEMS inertial navigation as claimed in claim 1, characterized in that: In S3, the corner point is calculated as follows: S3-2: When there are two or more wall points on the i-th wall, the least squares method is used to fit the first wall plane position line L according to all wall points when calculating the wall straight line. i : Assume that there are m points on the wall, m ≥ 2, and the mth point The coordinates of Will Substituting into the equation of the line we get Right now In formula (3), b1 and b2 represent coefficients; Similarly, the first m-1 points are substituted into the line equation and combined into a matrix form: make According to the least squares principle, we can solve Then we can get the straight line L i The equation y = b1 x + b2; Similarly, we get the second wall plane position line L corresponding to the i+1th wall i+1 ; Finally, the first wall plane position line L i and the second wall plane position line L i+1 The intersection point is the corner point, and its coordinates are 6. A method for measuring the profile of a house wall based on MEMS inertial navigation as claimed in claim 1, characterized in that: The present invention also includes S5: Obtain inertial navigation coordinates corresponding to a first distance and a second distance outside a building or a house to be measured, and obtain rotation parameters and translation parameters of the absolute coordinates and the inertial navigation coordinates according to a first absolute coordinate of the first distance, the first inertial navigation coordinates and the second absolute coordinate of the second distance, and the second inertial navigation coordinates; The coordinates of the wall points and corner points are converted to the absolute coordinate system according to the rotation parameters and translation parameters, and then the wall points and corner points in the absolute coordinate system are connected in sequence to complete the real estate surveying and mapping.

7. A device, characterized in that: It comprises a memory and a processor; the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements a house wall profile measurement method based on MEMS inertial navigation as described in any one of claims 1-6.

8. A readable medium, characterized in that The readable medium stores a computer program; when the computer program is executed by the processor, a method for measuring the contour of a house wall based on MEMS inertial navigation is implemented as described in any one of claims 1 to 6.

Images