Three-dimensional temperature field sensing device and method

Abstract

The invention belongs to the technical field of temperature field measurement, and discloses a three-dimensional temperature field sensing device and method. Wherein the three-dimensional temperature field sensing unit comprises a sensor mounting bracket (5), an ultrasonic sensor (6), a first steering engine mounting bracket (1-1), a first 180-degree steering engine (2-1), a first steering engine rotor wing (3-1), a second steering engine mounting bracket (1-2), a second 180-degree steering engine (2-2) and a second steering engine rotor wing (3-2), and the ultrasonic sensor is a transceiving integrated ultrasonic sensor. And the transmitting port and the receiving port are positioned on the same surface of the sensor mounting bracket. The mechanical structure based on the multi-axis holder is designed, the receiving and transmitting integrated ultrasonic sensor is carried, the orientation angle of the sensor is adjusted and fixed through the steering engine, and the three-dimensional temperature field sensing device is suitable for conducting three-dimensional temperature field sensing on a closed three-dimensional space. According to the transmitting-receiving integrated sensor and the multi-axis holder, the arrangement flexibility is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature field measurement. More specifically, it relates to a three-dimensional temperature field sensing device and method, which is applicable to three-dimensional temperature field sensing of a closed three-dimensional space (the walls in the space are not sound-absorbing materials). Background Art

[0002] In recent years, with the gradual complexity and diversification of temperature measurement application scenarios, non-contact temperature measurement methods have become a key research direction in the field of engineering technology due to their significant advantages, namely, they can effectively avoid the influence of the measurement environment and the measured medium on the measurement system. As a typical non-contact temperature measurement method, ultrasonic temperature measurement can indirectly calculate the temperature of the medium by measuring the sound speed in the medium, and has the characteristics of high accuracy in restoring the temperature field, simple structure, wide temperature measurement range, etc.

[0003] Current ultrasonic temperature measurement systems often target the measured medium distributed in a closed space, and most of them have the following characteristics: the acquisition and analysis of data, as well as the control of the entire measurement system, mainly rely on acquisition cards and PC machines; the ultrasonic transmitting and receiving devices are generally separately arranged at two positions in the space, and the receiving device directly obtains the signal of the transmitting device; both the ultrasonic transmitting and receiving devices need to be installed on the side of the space and have a fixed orientation, so they can only measure the temperature field of a two-dimensional plane at the same height. If three-dimensional space temperature field measurement is required, the height of the transmitting and receiving devices usually needs to be manually adjusted multiple times, and many inconveniences often occur during the process of repeatedly arranging sensors.

[0004] If the hardware cost and layout difficulty of the measurement system can be further reduced, such as using a low-power embedded microprocessor as the main control, and at the same time, the flexibility of device use and the adaptability of the measurement scenario can be enhanced, such as using a sensing device that can directly measure a three-dimensional space and making a three-dimensional improvement to the existing two-dimensional temperature field calculation method, it will undoubtedly promote the practical application of ultrasonic temperature measurement more effectively. Summary of the Invention

[0005] Aiming at the above defects or improvement requirements of the prior art, the purpose of the present invention is to provide a three-dimensional temperature field sensing device and method. By designing a mechanical structure based on a multi-axis gimbal, a transceiver-integrated ultrasonic sensor is carried, and the steering gear is used to adjust and fix the orientation angle of the sensor, which is applicable to three-dimensional temperature field sensing of a closed three-dimensional space (the walls in the space are not sound-absorbing materials). Different from the traditional transceiver-separated ultrasonic sensors that can only be separately installed on the side walls, the transceiver-integrated sensor and multi-axis gimbal of the present invention greatly improve the layout flexibility.

[0006] To achieve the above object, according to the first aspect of the present invention, a three-dimensional temperature field sensing unit is provided, which is characterized by including a sensor mounting bracket (5), an ultrasonic sensor (6), a first servo mounting bracket (1-1), a first 180-degree servo (2-1), a first servo rotor (3-1), a second servo mounting bracket (1-2), a second 180-degree servo (2-2), and a second servo rotor (3-2), wherein,

[0007] The first 180-degree servo (2-1) is mounted on the first servo mounting bracket (1-1), and the output shaft of the first 180-degree servo (2-1) is connected to the first servo rotor (3-1); the first servo rotor (3-1) is fixedly connected to a connecting member and can drive the connecting member to rotate 180 degrees through the first servo rotor (3-1) under the drive of the first 180-degree servo (2-1);

[0008] The second servo mounting bracket (1-2) is fixedly connected to the connecting member, the second 180-degree servo (2-2) is mounted on the second servo mounting bracket (1-2), and the output shaft of the second 180-degree servo (2-2) is connected to the second servo rotor (3-2); the output shaft of the first 180-degree servo (2-1) is perpendicular or skew perpendicular to the output shaft of the second 180-degree servo (2-2); the second servo rotor (3-2) is fixedly connected to the sensor mounting bracket (5) and can drive the sensor mounting bracket (5) to rotate 180 degrees through the second servo rotor (3-2) under the drive of the second 180-degree servo (2-2);

[0009] The ultrasonic sensor (6) is fixed on the sensor mounting bracket (5), and the ultrasonic sensor (6) is a transceiver integrated ultrasonic sensor, and the transmitting port and the receiving port are located on the same surface (S 1 ) of the sensor mounting bracket (5).

[0010] As a further preference of the present invention, the connecting member is a U-shaped bracket (4);

[0011] The first servo rotor (3-1) is fixedly connected to the bottom surface of the U-shaped bracket (4) and can drive the U-shaped bracket (4) to rotate 180 degrees through the first servo rotor (3-1) under the drive of the first 180-degree servo (2-1);

[0012] The second servo mounting bracket (1-2) is inserted and mounted in the U-shaped bracket (4).

[0013] As a further preference of the present invention, in the first 180-degree angle servo (2-1), the surface opposite to the first servo rotor (3-1) is defined as the bottom surface (S 2 ) of the first 180-degree angle servo (2-1), and at the same time is also defined as the back surface (S 2 ) of the entire sensing unit;

[0014] The distance from the rotation axis of the second servo rotor (3-2) to the bottom surface (S 2 ) of the first 180-degree angle servo (2-1) does not exceed 6 cm.

[0015] As a further preference of the present invention, the three-dimensional temperature field sensing unit can be arranged relatively or back-to-back in space in the form of any two combinations;

[0016] If two three-dimensional temperature field sensing units are arranged relatively in space, then the output shafts of the first 180-degree angle servos (2-1) of the two are collinear and at the same height in space, and the back surfaces (S 2 ) of the two sensing units do not point at each other, and in the rotation range, the coverage areas of the ultrasonic wave emission paths emitted by the ultrasonic sensors (6) of the two in space must cross and overlap;

[0017] If two three-dimensional temperature field sensing units are arranged back-to-back in space, then the output shafts of the first 180-degree angle servos (2-1) of the two are collinear and at the same height in space, but the back surfaces (S 2 ) of the two sensing units both point at each other, and in the rotation range, the coverage areas of the ultrasonic wave emission paths emitted by the ultrasonic sensors (6) of the two in space do not cross and overlap.

[0018] According to the second aspect of the present invention, the present invention provides a three-dimensional temperature field sensing device for performing three-dimensional temperature field sensing on an isometric measured space, which is characterized in that it includes 4 above-mentioned three-dimensional temperature field sensing units, and these 4 three-dimensional temperature field sensing units are respectively denoted as S A , S B , S C , S D , wherein,

[0019] S A and S B are arranged relatively on a group of opposite side walls in the space, and the projections of S A , S B on the horizontal plane of the space respectively overlap with the midpoints of the horizontal projection line segments of these 2 side walls, the output shafts of the first 180-degree angle servos (2-1) of the two are collinear, and are at the same height in space, and in the rotation range, the coverage areas covered by the ultrasonic wave emission paths emitted by the ultrasonic sensors (6) of the two cross and overlap;

[0020] S C and S D are oppositely arranged on another set of opposite side walls within the space. The projections of S C , S D on the horizontal plane of this space respectively overlap with the midpoints of the horizontal projection line segments of these two side walls. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, and they are at the same height in the space. Moreover, within the rotation range, the regions covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap;

[0021] S A The output shaft of the first 180-degree angle servo motor (2-1) of is perpendicular to the output shaft of the first 180-degree angle servo motor (2-1) of S C in the space;

[0022] S A and S B The connection line of and S C and S D are at the same height and perpendicularly intersect in the space. Among them, denote the projection of the connection line of S A and S B on the horizontal plane as the first connection line, and the projection of the connection line of S C and S D on the horizontal plane as the second connection line. Then, the rectangle constructed with the first connection line and the second connection line can completely cover the projection of this space on the horizontal plane; one side of the rectangle is parallel to the first connection line, and the other side is parallel to the second connection line.

[0023] According to the third aspect of the present invention, the present invention provides a three-dimensional temperature field sensing device for sensing the three-dimensional temperature field of an isometric measured space, which is characterized in that it includes 4 above-mentioned three-dimensional temperature field sensing units, and these 4 three-dimensional temperature field sensing units are respectively denoted as S A , S B , S C , S D , among which,

[0024] (i) When the shape of the projection boundary of the measured space on the horizontal plane is a rectangle:

[0025] S A and S B are oppositely arranged on a set of opposite side walls within the space. S A , S BThe projections on the horizontal plane of this space respectively overlap with the midpoints of the horizontal projection line segments of these two side walls. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, have the same height in space, and within the rotation range, the regions covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two cross and overlap;

[0026] S C and S D Are arranged back to back at the geometric center of the space. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, have the same height in space, and within the rotation range, there is no overlapping part in the regions covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two;

[0027] S A The output shaft of the first 180-degree angle servo motor (2-1) of S C Is perpendicular in space to the output shaft of the first 180-degree angle servo motor (2-1) of S

[0028] S A and S B The connection line of S C and S D Is of the same height and perpendicularly intersects in space;

[0029] (ii) If the shape of the projection boundary of the measured space on the horizontal plane is a T-shape formed by the edge-to-edge overlap and intersection of two rectangles:

[0030] Denote the overlapping space of the two rectangles as the common space. The projection of this common space on the horizontal plane is a rectangle. Then, three sides of this rectangle are within the projection area of the measured space on the horizontal plane, and one side overlaps with the projection boundary of the measured space on the horizontal plane;

[0031] S A and S B Are relatively arranged on a set of opposite side walls within the space. Among them, the projection of S A On the horizontal plane of this space is on the only side that overlaps with the projection boundary of the measured space on the horizontal plane within the common space, while the projections of S A and S B On the horizontal plane of this space respectively overlap with the midpoints of the horizontal projection line segments of these two side walls. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, have the same height in space, and within the rotation range, the regions covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two cross and overlap;

[0032] S C and S DSet back-to-back at the geometric center of the shared space, the output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, and they are at the same height in the space. Moreover, in the rotation range, there is no overlapping part in the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two;

[0033] S A The output shaft of the first 180-degree angle servo motor (2-1) of C is perpendicular in space to the output shaft of the first 180-degree angle servo motor (2-1) of

[0034] S A and B The connection line between C and D is at the same height in space as and perpendicular to the connection line between

[0035] (iii) If the shape of the projection boundary of the measured space on the horizontal plane is an L shape formed by the overlapping intersection of the sides of two rectangles:

[0036] Record the overlapping space of the two rectangles as the shared space. The projection of this shared space on the horizontal plane is a rectangle. Then, two adjacent sides of this rectangle are within the projection area of the measured space on the horizontal plane, and the other two adjacent sides overlap with the projection boundary of the measured space on the horizontal plane;

[0037] In the rectangular projection of the shared space on the horizontal plane, there are two adjacent sides that overlap with the projection boundary of the measured space on the horizontal plane. The projections of A , B on the horizontal plane are respectively set on these two adjacent sides and overlap with the midpoints of these two adjacent sides;

[0038] S C and D Set back-to-back at the geometric center of the shared space, the output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, and they are at the same height in the space. Moreover, in the rotation range, there is no overlapping part in the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two;

[0039] S A The output shaft of the first 180-degree angle servo motor (2-1) of B is at the same height in space as and perpendicular to the output shaft of the first 180-degree angle servo motor (2-1) of C and D The intersection point is the midpoint of the connection line between C and D and is at the same height as the connection line between

[0040] In the horizontal projection rectangle of the shared space, there are two adjacent sides that overlap with the projection boundaries of the measured space on the horizontal plane, and these two adjacent sides can form a right triangle when combined with a rectangle diagonal in the horizontal projection rectangle of the shared space. Then S C and S D The projection of the connection line on the horizontal plane coincides with the hypotenuse in this right triangle.

[0041] According to the fourth aspect of the present invention, the present invention provides a three-dimensional temperature field sensing device for performing three-dimensional temperature field sensing on a measured space with the same height. It is characterized in that it includes 4 above-mentioned three-dimensional temperature field sensing units, and these 4 three-dimensional temperature field sensing units are respectively denoted as S A 、S B 、S C 、S D , where

[0042] S A and S B Are arranged back to back at the geometric center of the space. The output shafts of their first 180-degree angle servo motors (2-1) are collinear, and they are at the same height in the space. And in the rotation range, the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two do not overlap;

[0043] S C and S D Are relatively arranged on a set of opposite side walls in the space. The projections of S C and S D on the horizontal plane of the space respectively overlap with the midpoints of the horizontal projection line segments of these 2 side walls. The output shafts of their first 180-degree angle servo motors (2-1) are collinear, and they are at the same height in the space. And in the rotation range, the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two cross and overlap;

[0044] S A 、S B 、S C 、S D The output shafts of the first 180-degree angle servo motors (2-1) of the four are collinear, and they are at the same height in the space. They are arranged in sequence according to S C 、S A 、S B 、S D ;

[0045] At the same time, if the space is evenly divided into two sides by the dividing interface located at the geometric center of S A and S B , then, S C and S A Are relatively arranged on one side, S B and S DAre arranged oppositely on the other side.

[0046] According to the fifth aspect of the present invention, the present invention provides a three-dimensional temperature field sensing device for sensing the three-dimensional temperature field of a measured space with the same height. It is characterized in that it includes 4 above-mentioned three-dimensional temperature field sensing units, and these 4 three-dimensional temperature field sensing units are respectively denoted as S A , S B , S C , S D , wherein,

[0047] The space is evenly divided into two sides. S A and S B are arranged back to back at the geometric center of one side space. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, and they are at the same height in the space. And in the rotation range, the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two do not overlap;

[0048] S C and S D are arranged back to back at the geometric center of the other side space. The output shafts of the first 180-degree angle servo motors (2-1) of the two are collinear, and they are at the same height in the space. And in the rotation range, the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two do not overlap;

[0049] S A , S B , S C , S D The output shafts of the first 180-degree angle servo motors (2-1) of the four are collinear, and they are at the same height in the space. They are arranged in sequence according to the order of S A , S B , S C , S D ;

[0050] At the same time, the area covered by the ultrasonic emission path emitted by the ultrasonic sensor (6) of S B overlaps with the areas that can be covered by S C , S D . The area covered by the ultrasonic emission path emitted by the ultrasonic sensor (6) of S C overlaps with the areas that can be covered by S B , S A . S A and S D are arranged back to back.

[0051] According to the sixth aspect of the present invention, the present invention provides a method for calculating the ultrasonic trajectory via a grid in a three-dimensional space, which is used in cooperation with the above-mentioned three-dimensional temperature field sensing unit or the above-mentioned three-dimensional temperature field sensing device, and is characterized by including the following steps:

[0052] (1) According to the preset shape and geometric size of the measured three-dimensional space, preprocess the measured three-dimensional space and coordinate it using the space rectangular coordinate system Oxyz, so that the measured three-dimensional space can be completely divided into n cube-shaped grids, and the edge length of each grid is l 0 ; Then, calculate the center coordinates C j (x grid-j , y grid-j , z grid-j ) and vertex coordinates

[0053] (2) According to the installation position of each three-dimensional temperature field sensing unit, and in each three-dimensional temperature field sensing unit, the stepping angle Δθ of the first 180-degree angle servo 1 , and the stepping angle Δθ of the second 180-degree angle servo 2 , determine all m ultrasonic trajectories, m > n; preferably, m ≥ 2n;

[0054] (3) From a top-down perspective, project each ultrasonic trajectory onto a two-dimensional plane respectively to present it in the grid in the xOy plane, and then calculate the perpendicular vectors from the 4 vertices of each grid in the plane to the straight line obtained by projecting the ultrasonic trajectory one by one; if the directions of the 4 perpendicular vectors of a certain grid are not completely the same, it means that the straight line obtained by projecting the ultrasonic trajectory passes through this grid in the xOy plane, thereby determining the x-dimension and y-dimension coordinates (x grid , y grid ) of the center point of this grid passed by this ultrasonic trajectory in space;

[0055] If it is determined that in the xOy plane, the straight line obtained by projecting a certain ultrasonic trajectory passes through the grid with the center point (x grid , y grid ), then according to the 4 vertex coordinates of this grid, calculate the coordinates (x 1 , y 1 ) and (x 2 , y 2 ) of the two intersection points of the straight line obtained by projecting this ultrasonic trajectory and the grid boundary, and further calculate the projection distance of this ultrasonic trajectory passing through this grid when projected onto the xOy plane, and establish the coordinates (x grid , ygrid ) and the one-to-one correspondence with the grid projection distance l xOy constitute a set H of calculation results of the xOy plane projection xOy {(x grid , y grid ), l xOy};

[0056] From the perspective of the right view, perform two-dimensional plane projections on each ultrasonic trajectory respectively to present it in the grid in the yOz plane, and then calculate the perpendicular vectors from the four vertices of each grid in the plane to the straight line obtained by the projection of the ultrasonic trajectory one by one. If the directions of the four perpendicular vectors of a certain grid are not completely consistent, it means that the straight line obtained by the projection of the ultrasonic trajectory passes through this grid in the yOz plane, thereby determining the y-dimension and z-dimension coordinates (y grid , z grid ) of the center point of the grid passed by this ultrasonic trajectory in space;

[0057] If it is determined that in the yOz plane, the straight line obtained by the projection of a certain ultrasonic trajectory passes through the grid with the center point (y grid , z grid ), then according to the four vertex coordinates of this grid the coordinates (y 1 , z 1 ) and (y 2 , z 2 ) of the two intersection points of the straight line obtained by the projection of this ultrasonic trajectory and the grid boundary can be calculated, and then the longitudinal height difference l Δz = |z 2 - z 1 | of this ultrasonic trajectory when projected onto the yOz plane can be calculated, and for the straight line obtained by projecting the same ultrasonic trajectory onto the yOz plane, establish a one-to-one correspondence between the coordinates (y grid , z grid ) of the center point of each passing grid and the longitudinal height difference l Δz of this grid, constituting a set H of calculation results of the yOz plane projection yOz {(y grid , z grid ), l Δz};

[0058] For an ultrasonic trajectory, the two sets of calculation results H xOy {(x grid , y grid ), l xOy} and H yOz {(y grid , z grid ), l Δz}, filter out the two-dimensional coordinate items with the same y-dimension among them, and then through (x grid , y grid ) and (y grid , z grid ), construct the center point coordinates (x pass-j , y pass-j , z pass-j ) of all the cube grids passed by this ultrasonic trajectory in the three-dimensional space. Then, according to the two-dimensional coordinate items (x grid , y grid ) and (y grid , z grid ) corresponding to the center point of a passed cube grid one by one, and the corresponding projection distance l xOy and the longitudinal height difference l Δz , calculate the space distance passed by this ultrasonic trajectory within a certain cube grid and combine the center point coordinates (x pass-j , y pass-j , z pass-j ) of all the cube grids passed by this ultrasonic trajectory, as well as the passed space distance l j , establish a one-to-one correspondence relationship to form a set H Oxyz {(x pass-j , y pass-j , z pass-j ), l j} of the space Oxyz calculation results of the ultrasonic trajectory;

[0059] (4) Substitute all m ultrasonic trajectories into n cube grids for calculation in turn, that is, first judge whether each ultrasonic trajectory passes through all n grids in turn; if it does not pass through, the space distance passed within the corresponding grid is counted as 0; if it passes through, then calculate the space distance passed within the cube, so as to obtain m sets of space Oxyz calculation result sets H Oxyz {(x pass-j , y pass-j , z pass-j ), l j}, and then the trajectory of the ultrasonic wave passing through the grid in the three-dimensional space can be solved; among them, for the i-th ultrasonic trajectory, the trajectory passing through the grid is the total space distance passed within all n grids, including a distance of 0 and a non-zero distance, 1 ≤ i ≤ m.

[0060] According to the seventh aspect of the present invention, the present invention provides a measurement data correction method for cooperating with the above three-dimensional temperature field sensing unit or the above three-dimensional temperature field sensing device, which is characterized by including the following steps:

[0061] According to the installation position S of the ultrasonic sensing unit and the rotation angle θ of the first servo motor1 , the rotation angle θ of the second servo 2 , calculate the straight line where a certain ultrasonic trajectory t emitted by the sensing unit is located, and infer the wall surface ρ that reflects this ultrasonic trajectory according to the preset three-dimensional spatial form;

[0062] According to the straight line where the ultrasonic trajectory t is located and the spatial relationship between the wall surface ρ that reflects this ultrasonic trajectory, calculate the line-plane angle β formed by the two; at the same time, define the complementary angle α of the line-plane angle as the angle between the straight line where the ultrasonic trajectory t is located and the wall surface ρ that reflects this ultrasonic trajectory, that is, satisfy α + β = 90°;

[0063] And the value range of the angle α between the ultrasonic wave and the wall is 0° ≤ α ≤ 75°;

[0064] Then, compare the step angle Δθ of the first 180-degree servo in the three-dimensional temperature field sensing unit 1 , and the step angle Δθ of the second 180-degree servo 2 , take the smaller value of the two and denote it as Δθ, that is, Δθ = min{Δθ 1 , Δθ 2};

[0065] For any ultrasonic trajectory t, with the unit of α being °, then calculate c according to the following formula Δθ (α):

[0066] When 1° ≤ Δθ ≤ 2°, then,

[0067] When 2° < Δθ < 4°, then,

[0068] When Δθ ≥ 4°, then,

[0069] If the original time data measured by the ultrasonic sensing unit is denoted as m(α, Δθ), and the data output after calibration is denoted as o(α, Δθ), then there is:

[0070] o(α, Δθ) = c Δθ (α)m(α, Δθ).

[0071] Through the above technical solution conceived by the present invention, compared with the prior art, the present invention utilizes the reflection of sound waves by the wall surface of a closed three-dimensional space (the wall surface within the space is not a sound-absorbing material), and arranges the ultrasonic transmitting and receiving devices at the same position, that is, an integrated ultrasonic transceiver device is formed (at this time, the receiving device can obtain the echo of the wall surface). At the same time, through the cooperation of the two 180-degree servo motors and the servo drive structure, the above-mentioned integrated ultrasonic transceiver device can control the horizontal orientation and pitch angle through the cooperation of the motor and the mechanical structure, enabling the mechanical structure to have the ability of multi-axis rotation and freely adjusting the orientation angle of the end plane of the entire mechanical structure, thereby realizing omnidirectionality in the three-dimensional space.

[0072] In the present invention, the integrated ultrasonic transceiver sensor is installed at the end plane of the mechanical structure. In the use scenario of a closed three-dimensional space, the wall echo can be effectively utilized without the need to cooperate with a fixed receiving device. Combining with the omnidirectionality of the mechanical structure and removing the restrictions caused by the fixation of the receiving device, it only needs to be fixedly installed once at a suitable position (the installation position can be not limited to the side, but also in the center of the space). The orientation angle of the end plane where the ultrasonic sensor is located can be adjusted arbitrarily, so it is very easy to achieve full coverage of the measurement range in the space and obtain the ability to measure the two-dimensional plane temperature field at various heights in the three-dimensional space, thus greatly improving the flexibility of the device layout.

[0073] Different from the traditional separate ultrasonic transceiver sensors that can only be separately installed on the side wall, the present invention is based on the mechanical structure of a multi-axis pan-tilt head and can be flexibly arranged in the use scenario. It can be installed on the side wall or installed in the center of the room through a bracket.

[0074] One of the key improvements of the present invention is to provide a method for resolving the ultrasonic trajectory through a grid in a three-dimensional space. The present invention realizes the sensing of the temperature field in the whole space by discretizing the three-dimensional space and then solving the temperature in all discrete grids. During the process of discretizing the three-dimensional space, it is necessary to first perform a certain preprocessing on it according to the shape and geometric size of the space, so that the processed size can divide the room into several cube-shaped grids. If it is necessary to solve the temperature in all discrete grids in the space, it is necessary to clarify the length of each ultrasonic sensing device's emission trajectory when passing through each grid in the space, that is, the grid passage of the ultrasonic trajectory; during the process of resolving the grid passage of the ultrasonic trajectory, the resolution result will be jointly affected by three factors: the grid division method, the installation position of the ultrasonic sensing device, and the deflection angles of the two servo motors in the sensing device; the method of the present invention is to first determine which grids a certain ultrasonic trajectory will pass through in the space, and then calculate the length of the ultrasonic trajectory in each passing grid one by one. Solving the problem of the division method of the cube grids in the space and the problem of resolving the grid passage of the ultrasonic trajectory can provide known and necessary numerical conditions for the process of solving the temperature in all discrete grids. Combining with the measured data of each ultrasonic sensing unit, the sensing of the temperature field in the whole space can be realized.

[0075] Another key improvement of the present invention is to provide a method for correcting the measured data of the sensing device under different working conditions. Since a transceiver-integrated ultrasonic sensor is used in the present invention and it needs to measure by receiving the echo from the wall, except for the most ideal working condition of emitting ultrasonic signals perpendicularly facing the wall, when emitting signals at different angles deviating from the perpendicular facing the wall, the direction of the wall's reflection of the echo signal will also deviate from the direction of the sensor receiving the echo signal, thus introducing additional errors during the measurement time. In order to obtain more accurate measurement results, that is, to weaken the measurement errors under non-ideal working conditions as much as possible, it is necessary to design corresponding correction methods for the factors introducing additional errors. During the operation of the sensing device, the angle α between the emitted ultrasonic trajectory and the perpendicular direction of the wall it contacts, and the smaller step angle Δθ of the two servo motors in the sensing device are two key factors introducing additional errors. The correction method will select different groups of correction formulas with α as the independent variable according to different Δθ ranges, calculate the correction coefficient corresponding to the current measured data, and after processing the measured data with the correction data, output it as the final measurement result, thus effectively weakening the adverse effects brought by the additional errors introduced under non-ideal working conditions. Description of the Drawings

[0076] Figure 1 It is a schematic diagram of the mechanical structure and its coverage range at the sensor end provided by the embodiment of the present invention; among them, Figure 1In (a) and (b) are respectively schematic diagrams of the mechanical structure at the sensor end from different perspectives; Figure 1 In (c) and (d) are respectively schematic diagrams of the coverage range of the ultrasonic emission path when an ultrasonic sensing unit is fixed on the inner side wall of an enclosed space from a three-dimensional perspective and a top-down projection perspective; Figure 1 In (e) and (f) are respectively schematic diagrams of the coverage range of the ultrasonic emission path when two ultrasonic sensing units are fixed on a vertical bracket in the center of the space in a "back-to-back" form from a three-dimensional perspective and a top-down projection perspective.

[0077] Figure 2 Shows four typical distribution methods that the sensor provided by the embodiment of the present invention can have when the measured area is a cuboid room, and a schematic diagram of the grid division form within the measured area.

[0078] Figure 3 Shows four typical distribution methods that the sensor provided by the embodiment of the present invention can have when the measured area is a "T"-shaped room.

[0079] Figure 4 Shows four typical distribution methods that the sensor provided by the embodiment of the present invention can have when the measured area is an "L"-shaped room.

[0080] Figure 5 Is the main operation logic diagram of the control program in the measurement and control system provided by the embodiment of the present invention.

[0081] Figure 6 Is the block diagram of the hardware organization architecture in the measurement system provided by the embodiment of the present invention.

[0082] Figure 7 、 Figure 8 Is a schematic diagram of the method for solving the grid of all ultrasonic trajectories in space in the measurement system provided by the embodiment of the present invention.

[0083] Figure 9 、 Figure 10 Is a schematic diagram of the correction algorithm for the obtained original time measurement result data in the measurement system provided by the embodiment of the present invention.

[0084] Figure 1 The meanings of the reference numerals in the figures are as follows: 1-1 and 1-2 are both servo mounting brackets, 1-1 is the first servo mounting bracket, and 1-2 is the second servo mounting bracket; 2-1 and 2-2 are both 180-degree servos (abbreviated as servos), 2-1 is the first 180-degree servo, and 2-2 is the second 180-degree servo; 3-1 and 3-2 are both servo rotors (abbreviated as rotors), 3-1 is the first servo rotor, and 3-2 is the second servo rotor; 4 is a U-shaped bracket, 5 is a sensor mounting bracket, 6 is an ultrasonic sensor, S0 is the installation reference plane, S 1 is the working plane, S 2 is the back surface of the entire sensing unit (abbreviated as the back surface; that is, the bottom surface of the first 180-degree servo in the sensing unit).

[0085] Figures 2 to 4 The 4 three-dimensional temperature field sensing units S shown in A 、S B 、S C 、S D have the same height (i.e., are on the same horizontal plane). Detailed implementation manners

[0086] In the following description, for the purpose of illustration rather than limitation, specific details of types such as specific system structures, technologies, functions, etc. are presented to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0087] It should be understood that when used in the specification and appended claims of the present application, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations. It should also be understood that the term "and / or" used in the specification and appended claims of the present application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0088] The three-dimensional temperature field sensing device of the present invention is based on the mechanical structure of a multi-axis gimbal. It can be further used in conjunction with a measurement and control system based on a microcontroller and a function module for solving and reconstructing the spatial temperature field. By using the measurement and control system based on a microcontroller, the movement of the mechanical structure can be controlled, the feedback signals of ultrasonic sensors can be processed, the measurement data can be calculated, and a graphical operation interface is realized in combination with a touch screen; by using an external memory, the measurement data and calculation results can be exported, and the configuration data of the system can be saved in real time for callback after power-off restart.

[0089] Among them, the mechanical structure based on the multi-axis gimbal includes: two servos with an output shaft rotation range of 180 degrees; several servo transmission structure parts; a set of servo mounting brackets; a transceiver integrated ultrasonic sensor. The two servos with an output shaft rotation range of 180 degrees are arranged at right angles to each other in space. For example, the first servo can provide pitch angle adjustment, connect to the second servo through a transmission structure, and the second servo can provide azimuth angle adjustment. Then, through another transmission structure, it connects to the end plane of the entire mechanical structure, finally forming a multi-axis gimbal. Regarding several servo transmission structure parts, first connect the second servo as a whole to the output shaft of the first servo, and then connect the end plane to the output shaft of the second servo. The end plane is the installation position of the ultrasonic sensor; the cooperation between the two servos with an output shaft rotation range of 180 degrees and several servo transmission structure parts enables the mechanical structure based on the multi-axis gimbal to have the ability of multi-axis rotation and can freely adjust the orientation angle of the end plane of the entire mechanical structure. A set of servo mounting brackets can be set and connected to the first servo (i.e., the first servo for adjusting the pitch angle), which can not only fixedly install the entire gimbal (that is, enable the entire mechanical structure part to be fixedly installed at a certain position), but also indicate whether the installation direction of the gimbal is correct (this is because the mounting bracket itself has a certain prompting function. Only when the mechanical structure is fixed and the servo mounting bracket is horizontal to the ground can the functions of the multi-axis gimbal be normally exerted). The transceiver integrated ultrasonic sensor is installed at the end plane, and its transceiver orientation angle can be freely adjusted following the end plane, and it can receive echo signals by using the reflection of the wall surface of the closed three-dimensional space (non-sound-absorbing material), so it also has omnidirectionality in three-dimensional space measurement. In the use scenario of a closed three-dimensional space, different from the traditional separate ultrasonic sensors for the receiving and transmitting units that can only be separately installed on the side walls, the combination of the transceiver integrated ultrasonic sensor and the multi-axis gimbal can be installed on the side walls or through a bracket in the center of the room, thus greatly improving the flexibility of equipment layout.

[0090] For the measurement and control system based on the microcontroller, it is a miniaturized and low-power electronic measurement system based on the microcontroller, and can include:

[0091] Multi-form human-computer interaction function modules, consisting of a 32-bit microcontroller, a capacitive touch liquid crystal screen, an external memory, a Bluetooth wireless module, an active buzzer, a small dot matrix liquid crystal screen;

[0092] The overall planning and control function module of the mechanical structure, which is implemented using the timer module in the microcontroller;

[0093] The function module for exporting measurement and configuration data, which is implemented using the external memory port in the microcontroller.

[0094] The electronic devices included in the mechanical structure, namely two 180-degree servo motors and a transceiver integrated ultrasonic sensor, are connected to the measurement system in different forms. Among them, the measurement system outputs control signals unidirectionally to the servo motors and transmits control and feedback signals bidirectionally to the ultrasonic sensor.

[0095] For example, the multi-form human-computer interaction function module specifically includes:

[0096] A capacitive touch liquid crystal screen, which designs a corresponding graphical interface according to the specific functions of the measurement system and can communicate bidirectionally with the microcontroller;

[0097] On the capacitive touch liquid crystal screen, directly clicking on the elements in the graphical interface can send the corresponding control instructions to the microcontroller, thereby changing the measurement parameters and controlling the start and stop of the measurement process;

[0098] A Bluetooth wireless module that can wirelessly forward the status information of the measurement system via Bluetooth at regular intervals, enabling the operator to monitor its operating status without touching the measurement system;

[0099] A small dot matrix liquid crystal screen that simply displays the key parameters of the measurement system;

[0100] An active buzzer that gives a feedback of successful instruction execution every time the operator sends a control instruction through the capacitive touch liquid crystal screen.

[0101] The overall control function module of the mechanical structure specifically uses the timer module in the microcontroller. This module can both output PWM (Pulse Width Modulation Encoding) signals and measure the pulse width of signals;

[0102] The two servo motors with an output shaft rotation range of 180 degrees are both controlled by the PWM signals output by the timer module, causing them to rotate to a certain angle and fix, thereby driving the end plane installed with the ultrasonic sensor to also obtain a definite orientation;

[0103] The transceiver integrated ultrasonic sensor measures the time interval from the emission of sound waves to the reception of echoes, that is, the total flight time of the sound waves, and feeds back a pulse signal with a high-level pulse width equal to the measurement result to the timer module in the microcontroller;

[0104] After the microcontroller receives the measurement result signal, by capturing and calculating its high-level pulse width, the time measurement result of the transceiver integrated ultrasonic sensor can be obtained.

[0105] The export function module for measurement and configuration data is specifically implemented by using the external memory port of the microcontroller and cooperating with an external memory through the SDIO (Secure Digital Input and Output) protocol.

[0106] After each change of the configuration parameters of the measurement system, the microcontroller will pack all relevant variables in the cache according to a certain data format, generate a configuration file and write it into the external memory.

[0107] This file will be updated in the form of automatically overwriting the original file each time it is written.

[0108] At the same time, when the microcontroller is powered on and started for the first time, it will automatically read the external memory and load the parameters saved last time in this configuration file into the cache.

[0109] After each measurement process is completed and the data processing is completed through software operations, the microcontroller will automatically save the raw data measured by the sensor and the data processed by the algorithm as two files respectively and write them into the external memory, thus realizing the export of measurement and calculation data.

[0110] That is to say, the control function of the servo motors in the mechanical structure part of the measurement system can be realized in the following form. Each of the two 180-degree servo motors included in each mechanical structure is connected to a timer channel of the microcontroller through a signal line; each timer channel of the microcontroller can output square wave signals with different frequencies and different duty cycles, that is, PWM (Pulse Width Modulation Coding) signals. For the convenience of control, the two 180-degree servo motors in the mechanical structure usually use the same model, and their control signal frequencies are the same, and the mapping relationship of the rotation angles (linearly positively correlated with the duty cycle of the PWM signal) is the same; after the microcontroller outputs the control signals of the two servo motors respectively, they will be fixed at a specific angle respectively, so that the end plane of the mechanical structure can also obtain a definite orientation.

[0111] The control function of the measurement system for the ultrasonic sensors in the mechanical structure part can be realized in the following form. One ultrasonic sensor contained in each mechanical structure is connected to a timer channel and a GPIO (General-Purpose Input / Output) channel of the microcontroller through two signal lines respectively. The GPIO channel of the microcontroller is used to output a short pulse signal as the start instruction for the ultrasonic sensor. After the ultrasonic sensor emits ultrasonic waves, the internal clock immediately starts timing. After receiving the echo, it calculates this time difference and feeds it back to the timer channel of the microcontroller through a long pulse signal (relative to the start instruction). The high-level pulse width of this long pulse signal is the emission / reception time difference of the ultrasonic sensor. The timer channel of the microcontroller also has the function of input capture, that is, it can time with a certain accuracy and measure the high-level pulse width of the input pulse signal. The long pulse signal fed back by the ultrasonic sensor can take half of its high-level pulse width as the flight time of the sound wave, which is used as the basis for calculating the sound speed in the later stage.

[0112] In addition, the human-machine interaction function of the measurement system can be realized in the following ways. The capacitive touch liquid crystal screen in the measurement system has designed a corresponding graphical interface according to the specific functions of the entire sensing device and can communicate bidirectionally with the microcontroller. By directly selecting elements in the graphical interface on the touch screen, the corresponding control instructions can be sent to the microcontroller. The control instructions include both the change of measurement parameters and the start and stop of the measurement and calculation processes. After receiving the control instructions, the single-chip microcomputer immediately changes the variables of the measurement parameters associated with the instructions or immediately executes the measurement / calculation operations described in the instructions, and at the same time feeds back the execution results of the instructions, including the updated measurement parameters and the progress of the measurement / calculation operations, to the corresponding display elements on the touch screen interface in real time. The small dot matrix liquid crystal screen in the measurement system unidirectionally receives the control signals output by the microcontroller, which are used to display the key state parameters of the entire sensing device, simplifies the content in the touch screen, and updates it synchronously to facilitate the operator to quickly view. The active buzzer in the measurement system unidirectionally receives the control signals output by the microcontroller. After the operator sends a control instruction by clicking on the touch screen each time, if the microcontroller successfully executes the instruction, while updating the content on the two display screens, the active buzzer will be enabled and emit a short beep to remind the operator. On the one hand, only when the instruction sent through the touch screen is successfully executed by the microcontroller will the buzzer sound, and the operator can use this as a basis for judging the effectiveness of the operation. On the other hand, if the operator accidentally makes a wrong operation, it can also be discovered and corrected in time through the sound prompt of the buzzer. The Bluetooth wireless module in the measurement system can forward the status information of the entire sensing device through the Bluetooth wireless channel at regular intervals, enabling the operator to monitor the operating status of the sensing device through devices with Bluetooth communication functions such as smartphones and personal computers without touching the sensing device.

[0113] The function module of the spatial temperature field solution and reconstruction algorithm solves the discrete temperature distribution by the least squares method and then reconstructs the entire temperature field through the interpolation algorithm. For example:

[0114] In a specific usage scenario, by modifying the measurement parameters, the measured spatial region can be divided into a certain number of cubic grids, and at the same time, the emission paths of the ultrasonic sensors are set, and it is ensured that at least two emission paths pass through all the divided grids;

[0115] Then, combined with all the set measurement paths, calculate the distances they pass through in all the divided grids. It should be noted that the number of set emission paths m is more than the total number of divided grids n, that is, it must satisfy m > n;

[0116] The temperature at any position within the same divided grid is regarded as consistent. Therefore, no matter what path the ultrasonic wave takes through the cube grid in space, it is regarded as having a consistent sound speed;

[0117] It should be supplemented that even if the control condition of m > n is satisfied, the grid division should not be too dense. Generally speaking, when the number of emission paths m is not less than twice the total number of divided grids n, the least squares method can obtain a better solution effect, and can be preferably set as: m ≥ 2n.

[0118] What is directly measured by the ultrasonic sensor is the total flight time of the sound wave in each set path, that is, the sum of the flight times within all the grids that the sound wave passes through in this path. Then, by combining the distances in different grids passed by each path, the sound speed in each grid can be taken as an unknown, and a system of equations can be listed for solution;

[0119] Since the number of set ultrasonic paths (i.e., the number of equations in the system of equations) is more than the total number of divided grids (i.e., the number of unknowns in the system of equations), this system of equations has no solution in the algebraic sense. It is necessary to use the least squares method to solve the best least squares solution of the sound speed in each grid as the basis for solving the discrete temperature distribution in the measured area;

[0120] Through the relationship formula between the sound speed and the temperature, combined with the best least squares solution of the sound speed in each grid, the temperature in all divided grids can be obtained, that is, the discrete temperature distribution in the measured area. Regarding the initially obtained discrete temperature distribution as the temperature value at the geometric center point of each grid, and then combining algorithms such as linear interpolation, spline interpolation, and Lagrange interpolation, the temperature field in the entire measured area can be reconstructed.

[0121] The calculation function of the measurement system for the measurement data can be realized in the following form. The microcontroller first calculates each emission trajectory of each ultrasonic sensor according to the measurement parameters used in this measurement process, including the number, position, and emission angle of the ultrasonic sensors; then, according to the geometric size, the number of grid divisions, and the grid division method of the measurement area, etc., it can calculate which grids each trajectory of all ultrasonic sensors will pass through, and the specific length of each trajectory within the grids it passes through; number each trajectory with i and each grid with j, then the distance of the i-th trajectory passing through the j-th grid is denoted as s ij If the i-th trajectory does not pass through the j-th grid, then denote s ij = 0. Generally speaking, each grid will have at least 2 emission trajectories of ultrasonic waves passing through, and the total number m of the emission trajectories is set to be greater than the number n of divided grids. Therefore, a full-column rank matrix S = [s ij m×n ​, each row in the matrix represents the distances within different grids passed by the same trajectory (the subscript i of s ij is consistent), each column in the matrix represents the lengths of different trajectories passed within the same grid (the subscript j of s ij is consistent), and the above parameters satisfy (preferably m ≥ 2n). Within the same divided grid, the temperature at any position is considered the same. Therefore, for all ultrasonic trajectories passing through the same grid, their sound speeds are regarded as the same; denote the sound speed in the j-th grid as c j , then the original numerical range 1 ≤ j ≤ n can still be used, take the reciprocals of the sound speeds in all n grids and construct an n-dimensional column vector For each ultrasonic sensor, the measured value is the total flight time of each ultrasonic trajectory. If the ultrasonic wave is regarded as being immediately reflected by the wall in practical applications, then for a certain trajectory, the one-way flight time can be directly taken as half of the total flight time; denote the one-way flight time of the i-th trajectory as t i , then the original numerical range 1 ≤ i ≤ m can still be used, construct the one-way flight times of all m trajectories into an m-dimensional column vector T = [t i m×1 . For a specific i-th trajectory, its one-way flight time t i is equal to the sum of the flight times within all the grids it passes through; specifically in terms of calculation steps, divide the distance s ij of this trajectory within each passed grid by the sound speed c j in this grid, and the flight time of the trajectory within a certain passed grid can be obtained Then sum up the flight times within all the passed grids, and the flight time t i of this trajectory can be obtained. Written as a mathematical expression, it is Based on the m transmitted trajectories and n grids that have been constructed, a system of linear equations with m equations and n unknowns can be listed, and can be expressed in matrix form as S m×n C n×1 = T m×1 , where S m×n and T m×1 matrices are known, and the C n×1 matrix is the unknown to be solved; since the coefficient matrix S m×n of this system of linear equations is a column full-rank matrix, that is, its number of rows (number of equations) m is greater than the number of columns (number of unknowns) n, so this system of linear equations is theoretically unsolvable. If the system of linear equations SC = T has no solution, it also means that the modulus of the vector (SC - T) m×1 is not equal to 0, but we can still obtain the optimal least squares solution C * such that the vector (SC​* -T) m×1 has the minimum norm length, that is, an optimal solution C with the minimum error is found for the original linear equation system SC = T * ; if the coefficient matrix S m×n is a column full-rank matrix, its pseudo-inverse matrix can be calculated first The calculation formula is S + =(S T S) -1 S T , where is the transpose matrix of the original coefficient matrix S m×n , and the subscript -1 indicates taking the inverse of this n-order square matrix; after obtaining the pseudo-inverse matrix of the coefficient matrix, the best least-squares solution can be calculated. The expression is , that is, the best least-squares solution of the reciprocal of the sound speed in all n grids Modern microcontrollers are usually equipped with a floating-point arithmetic unit and common operation modules such as matrix transpose, multiplication, and inversion. Therefore, the above algorithm can be easily implemented through a software program in the microcontroller. After calculating the best least-squares solution , the sound speed in each grid is also calculated accordingly. Then, combined with the relationship formula between the sound speed and temperature in the medium, the temperature in the grid can be inversely solved; taking air, a common medium, as an example, if the temperature of air in the j-th grid is t air,j (°C), then after measuring the sound speed in this grid, the relationship between the two can be expressed as where γ = 1.402 is the adiabatic index of air and is the gas constant of air. After transforming the relationship formula into , the temperature in the grid can be calculated through the sound speed. Since the number of grids divided in the measurement area is limited, the grid temperatures calculated through the above process can be regarded as the temperature values at the geometric center points of each grid. Then, combined with the existing temperature data and using an interpolation algorithm, the temperature values at different positions between the geometric center points of the grids can be deduced, and the temperature field in the entire measurement area can be reconstructed; algorithms such as linear interpolation, spline interpolation, and Lagrange interpolation can all be implemented through a software program in the microcontroller and can be selected according to different numbers of grid divisions and grid division methods when reconstructing the temperature field to achieve the best temperature field reconstruction effect.

[0122] The data storage function of the measurement system can be realized in the following manner. The external memory equipped in the measurement system can communicate bidirectionally with the microcontroller; the hardware part of the microcontroller includes a physical port of the SDIO (Secure Digital Input Output) protocol for data interaction with the external memory; the software part of the microcontroller includes a driver module for docking with the FAT (File Allocation Table) file system. Through the combination of software and hardware in the microcontroller, the measurement data obtained through the sensor and the calculation data after algorithm processing can be conveniently packaged into files and written into the external memory; the configuration parameters in the sensing device can also be saved as files in real time, written into the external memory, and read after each device restart, without having to repeat the configuration. The FAT file system used by the external memory is supported by almost all modern personal computers. It can be accessed through a reading device adapted to the SDIO protocol to directly access the saved measurement and calculation data and back up it to the computer for further use; the saved configuration files can also be modified or backed up, so that specific configuration parameters can be directly used after restarting the device.

[0123] The following are specific embodiments:

[0124] Embodiment 1——

[0125] As Figure 1 shown in (a) and (b) of, the mechanical structure of the sensor end in the embodiment of the present invention includes the following parts: two servo mounting brackets 1-1 and 1-2, two 180-degree servos 2-1 and 2-2, two servo rotors 3-1 and 3-2, a U-shaped bracket 4, a sensor mounting bracket 5, and an ultrasonic sensor 6. Among them, the two sheet-like servo mounting brackets 1-1 and 1-2 realize a primary commutation of the servo rotation axis in space through the U-shaped bracket 4. Among them, the servo mounting bracket 1-1 is parallel to the bottom surface of the U-shaped bracket 4, and the servo mounting bracket 1-2 is inserted into the U-shaped bracket 4, so that the plane where the servo mounting bracket 1-1 is located is perpendicular to the plane where the servo mounting bracket 1-2 is located. Since the two servo brackets are perpendicular to the rotation axes of their respective servos, the rotation axes of the servos 2-1 and 2-2 are also perpendicular, thus realizing a primary commutation of the rotation axis; the servo 2-1 is installed on the servo mounting bracket 1-1, and its rotor 3-1 is fixedly connected to the bottom surface of the U-shaped bracket 4, and can drive the U-shaped bracket 4 to have an up-and-down pitching rotation range of 180 degrees under the drive of the servo 2-1; the servo 2-2 is installed on the servo mounting bracket 1-2, and the sensor mounting bracket 5 is installed on its rotor 3-2, and the ultrasonic sensor 6 is installed on the sensor mounting bracket 5, and can have a left-and-right swing rotation range of 180 degrees under the drive of the servo 2-2. Define the upper end surface of the servo 2-1 as the installation reference plane S 0 , and define the plane where the transmitting / receiving port of the ultrasonic sensor 6 is located as the working plane S 1, define the bottom surface of the servo 2-1 (i.e., the surface of the servo 2-1 opposite to its rotor 3-1) as the back surface (abbreviated as the back surface) S of the entire sensing unit 2 .

[0126] The ultrasonic sensor in the embodiment of the present invention can measure the temperature in a three-dimensional enclosed space precisely relying on the above-mentioned mechanical structure at the sensor end. Taking a cuboid room as an example of the three-dimensional enclosed space, the basic characteristics and working principle of this mechanical structure can be described as follows: First, the servo 2-1 is installed on the servo mounting bracket 1-1, and the servo mounting bracket 1-1 needs to be fixed on the inner side wall of the enclosed space or on the vertical bracket in the center of the space, so that the installation reference plane S 0 simultaneously meets the requirements of facing upward, being parallel to the ground, and for the convenience of measurement and calculation, this mechanical mechanism is generally installed at half of the space height; then, the central axis of the rotor 3-1 is installed on the output shaft of the servo 2-1, and the two are driven by means of gear meshing; next, the U-shaped bracket 4 is installed on the rotor 3-1 so that it can rotate synchronously with the rotor 3-1, and the horizontal center line of the rotor is always parallel to the bottom center line of the U-shaped bracket; there is enough space in the central part of the U-shaped bracket 4 for the installation of the servo mounting bracket 1-2, and the servo mounting bracket 1-2 is always kept parallel to the horizontal center line of the rotor 3-1; subsequently, the installation forms of the servo 2-2 and the rotor 3-2 are the same as those of the previous servo 2-1 and rotor 3-1; the sensor mounting bracket 5 is fixed on the rotor 3-2, and the bottom surface of 5 can rotate synchronously with the rotor 3-2, driving the top surface of 5 to be parallel to the horizontal center line of the rotor 3-2; the ultrasonic sensor 6 is installed on the upper side of 5, and it should be noted that the emission / reception port of the ultrasonic sensor 6 faces the outside of the upper side of 5, which is defined as the working plane S 1 orientation.

[0127] Through the two 180-degree servo motors 2-1 and 2-2, and the mechanical structure parts of the rest, finally, the working plane S 1 can be driven to pitch up and down and swing left and right, so that the ultrasonic sensor 6 can perform the ultrasonic receiving / transmitting operation on the positions at different directions and different heights within the 180-degree left and right swing range in the enclosed space. Still taking the cuboid room as an example, Figure 1 in (c), (e) and (d), (f) respectively show the three-dimensional perspective in the Oxyz coordinate system and the top-down projection perspective in the xOy coordinate system, presenting two typical installation forms in the room. Different installation positions can be selected, and different numbers of ultrasonic sensors can be selected and matched. Using a single ultrasonic sensor or a combination of several ultrasonic sensors, the entire enclosed space can be covered. For example:

[0128] If it is selected to be installed at the midpoint of the side wall and the installation height is half of the room height, as Figure 1 shown in (c) and (d) of

[0129] below, then using 1 sensor-end mechanical structure is sufficient to cover the entire room relying on the left and right swing range of 180 degrees; 2 If it is selected to be installed on the vertical bracket in the center of the space, two sensor-end mechanical structures can be used. Install them "back to back" in the center of the room, and the installation height is half of the room height, that is, at this time, the backs S of the two sensing units Figure 1 are at the same height and both point to the back of each other, as shown in (e) and (f) of

[0130] below, so that the left and right swing ranges of the two 180 degrees are combined into a form of a complete 360-degree circle to achieve the coverage of the entire room.

[0131] Example 2 -

[0132] This embodiment uses at most 4 sensor-end mechanical structures in the above Example 1, and correspondingly, a total of at most 4 ultrasonic sensors are provided; these 4 sensors are numbered S A , S B , S C , S D , as shown in Figure 2 below. The ultrasonic emission paths of each ultrasonic sensor are represented by thin lines. In the embodiment of the present invention, it is planned to select ultrasonic sensors with a larger detection angle. Even if the direction of the ultrasonic wave emitted by the sensor is not the ideal situation perpendicular to the wall surface, the sensor can correctly receive the reflected echo of the wall surface in the same direction. Therefore Figure 2 the ultrasonic reflection paths in Figure 2 can be regarded as consistent with the emission paths. At the same time, in

[0133] below, taking a cuboid room as an example, the grid division form within the measured area is also shown; if the geometric shape of the boundary of the measured area is regular, generally the area inside will be evenly divided into several cube grids, and the projection of the grid boundary within the area is represented by a dotted line in the figure. Figure 2Four typical sensor position distribution methods are respectively shown, which are: (a)(b) middle-mounted distribution with four sides attached to the wall, (c)(d) middle-mounted / space-middle-mounted distribution with the long side attached to the wall, (e)(f) middle-mounted / space-middle-mounted distribution with the short side attached to the wall, (g)(h) completely space-middle-mounted distribution. Among them Figure 2 (a)(c)(e)(g) in it show the sensor positions in the three-dimensional space under the entire Oxyz coordinate system from an axonometric perspective. Figure 2 (b)(d)(f)(h) in it show the sensor positions and the projection of the ultrasonic trajectory in the xOy plane from a top view perspective. Combining Figure 1 (c) and (d) in it, and Figure 1 (e) and (f) in the two sets of figures, the typical installation forms shown Figure 2 For the four typical position distributions shown, it can be realized that in each grid in the entire room, there are at least two ultrasonic waves emitted by different sensors that can pass through. If the traditional side-wall installation method (a)(b) is adopted, then theoretically at least only 2 sensors are required, and any two opposite side midpoints are set relatively, and the entire room can be covered. One of the innovation points in the embodiment of the present invention is that if all 4 sensors are used, 2 of them can be set back-to-back on the vertical bracket in the center of the room in the form shown in (c)(d) and (e)(f), and even all 4 sensors can be set back-to-back on the vertical bracket in the center of the room in the form shown in (g)(h), and it is not necessarily required to set all the sensors relatively on the side wall. No matter which of the above distribution methods is adopted, as long as the control part of the mechanical structure is modified in the control program according to the grid division form in the specific measured area, and the orientation angle interval of each ultrasonic sensor during each measurement is reasonably adjusted, a sufficient total number of emission paths can be obtained, so that the temperature field in the three-dimensional enclosed space can be successfully calculated through the measurement data.

[0134] It should be noted that when two sensors are set back-to-back on the vertical bracket in the center of the room, the center distance between them (that is, in a sensing unit, the distance between the rotation axis of the second servo rotor 3-2 and the bottom surface of the first 180-degree servo 2-1 (that is, the back surface of the entire sensing unit) S 2 and the distance between the rotation axis of the second servo rotor 3-2 and the bottom surface of the first 180-degree servo 2-1 (that is, the back surface of the entire sensing unit) S 2 in another sensing unit) is generally less than 12 cm. This short distance accounts for a very small proportion of the size of the entire room. Therefore, in practical applications, it can be considered that these two sensors can be combined into a "new sensor" with 360-degree full coverage ability through the "coaxial rotation" method. In order to distinguish specific two sensors set back-to-back in the "back-to-back" form,Figure 2 The ratio of the center distance between the two to the size of the entire room is exaggerated to some extent and does not represent the installation form in actual applications.

[0135] The above embodiments are only illustrative. For example, in addition to the enclosed three-dimensional space in the shape of a cuboid, the present invention is also applicable to enclosed three-dimensional spaces of other three-dimensional shapes, such as "T"-shaped and "L"-shaped enclosed three-dimensional spaces. As Figure 3 shown, it is a top-down view showing the positions of the sensors in the xOy plane within a "T"-shaped room; at this time, four sensors S A 、S B 、S C 、S D at the same height in the space can either be all oppositely arranged as shown in (a) of Figure 3 , or a pair of sensors can be oppositely arranged and the other pair of sensors can be arranged back to back as shown in (b) of Figure 3 . As Figure 4 shown, it is a top-down view showing the positions of the sensors in the xOy plane within an "L"-shaped room; at this time, four sensors S A 、S B 、S C 、S D at the same height in the space can either be all oppositely arranged as shown in (a) of Figure 4 , or a pair of sensors can be vertically arranged and the other pair of sensors can be arranged back to back as shown in (b) of Figure 4 .

[0136] Embodiment 3——

[0137] The above three-dimensional temperature field sensing device can be used in conjunction with an electronic measurement system based on a microcontroller, which is miniaturized and low-power.

[0138] The embodiments of the present invention exemplify the control program in the measurement and control system. Figure 5The figure shows the main operation logic diagram of the control program in the measurement and control system. The control program is burned into the microcontroller (MCU). After the system is powered on, an initialization process is executed once, and then it enters an infinite servo loop process until the system is manually powered off. Since the cache (RAM) of the microcontroller is volatile memory, and the non-volatile flash memory has problems such as small capacity, inconvenient access, and complex management, in the embodiment of the present invention, an external memory (Micro SD card) with the FAT32 file system is selected as the storage medium for non-static data such as configuration parameters, measurement results, and calculation results. On the one hand, compared with the flash memory capacity (in KB) of the microcontroller, the capacity of the external memory is often larger (in GB), and it can store tens of thousands of measurement and calculation results; on the other hand, almost all current operating systems support storage devices with the FAT32 file system for reading and writing, and can perform convenient and fast file management through a graphical interface.

[0139] The main operation logic of the control program can be divided into two major processes according to Figure 5 each step shown in the figure: the part before and including "initializing each peripheral of the system according to the configuration parameters" is the "initialization process"; and the part after and including "the MCU monitors the serial port instructions of the touch screen" is the "infinite servo loop process". Now, these two major processes will be described in detail respectively:

[0140] The "initialization process" is only executed once after the system is powered on. First, it initializes the configuration variables in the microcontroller with default values, and then reads the external memory to check whether it contains a configuration file. The configuration file is a text file with a certain format, which contains the prompts and custom values of each configuration parameter: if any of the three situations of the configuration file not existing, the format of the configuration file being incorrect, and the value range of the configuration parameter being abnormal is detected, it is determined that the configuration file is illegal, and the configuration parameters in the system remain the default values without change; if there are no such problems above, it is considered that the configuration file is legal, and at this time, each configuration parameter in the configuration file will be updated to the system one by one. Finally, the control program initializes each peripheral of the system according to the configuration parameters (whether to keep the default value or update to the custom value depends on whether the configuration file in the previous step is legal), and the "initialization process" ends.

[0141] The "infinite servo loop process" will continue to run after the control program finishes the "initialization process" until the system is shut down by manually cutting off the power. The microcontroller continuously monitors a specific serial port and constantly compares the data received through the serial port with the preset instructions until the serial port data matches the preset instructions. Since the human-machine interaction of the control program is implemented through a touch screen with a graphical interface, and this touch screen communicates two-way control instructions with the microcontroller through this specific serial port, it can be regarded as playing the role of "total control": If the touch screen is clicked to make the serial port data match the instructions related to the "configuration mode", at this time, the key parameters during measurement can be customized by continuing to click the touch screen. And every time any configuration parameter is modified, a new configuration file will be generated, written into the external memory and overwrite the original one to ensure that the real-time update of the configuration parameters is saved; If the touch screen is clicked to make the serial port data match the instructions related to the "measurement and calculation mode", at this time, the file number for saving the measurement and calculation results can be set by continuing to click the touch screen, and the measurement and calculation process will be started, that is, first control the sensor to measure, then calculate according to the measurement results, and finally package the measurement and calculation results into a file and write it into the external memory (during the process of writing into the external memory, if it is detected that there is already a measurement and calculation result file with the corresponding number in the external memory, the old file will be overwritten by the latest measurement and calculation result file). Whether it is the above-mentioned "configuration mode" or "measurement and calculation mode", both take writing into the external memory as the end flag of execution. After that, it will return to the process where the microcontroller continuously monitors the specific serial port (that is, the serial port to which the touch screen is mounted) until the next matching instruction is input by clicking the touch screen. The above content is the way of execution in each loop process of the "infinite servo loop process".

[0142] After the system is powered off and shut down, the external memory can be taken out from the slot of the microcontroller and connected to the computer through a reading device (Micro SD card reader), and then the computer can be used to access the configuration file and measurement data. The measurement data file will give the detailed configuration parameters involved, all sensor measurement values, and all calculation results during this measurement process for further data processing. Since a latest configuration file is saved every time the configuration parameters are modified, it is also possible to customize the initialization of specific configuration parameters after the next power-on by modifying the configuration file in the external memory; The configuration file can also be copied to the computer as a backup or template for subsequent use; If you want to reset all configuration parameters after the next power-on, just delete the configuration file (or move it to other locations in the computer).

[0143] Embodiment 4——

[0144] The embodiments of the present invention exemplify the hardware devices in the measurement control system. AsFigure 6 As shown in the figure, it is the hardware architecture of the measurement system in the embodiment of the present invention, which mainly includes seven parts: a microcontroller, a capacitive touch liquid crystal screen, an external memory, a Bluetooth wireless module, a small dot matrix liquid crystal screen, an active buzzer, and four groups of sensor combinations. Among them, the microcontroller is the signal and instruction processing center of the system, the capacitive touch liquid crystal screen is the human-computer interaction interface assembly of the system, and the external memory is used to store all configuration data and measurement data of the system; after each operation is executed through the human-computer interaction interface, the Bluetooth wireless module will immediately feedback the detailed information of this operation externally, the small dot matrix liquid crystal screen will update the brief status of the system after the operation in real time, and the active buzzer will also emit a short beep to remind the operator. The four groups of sensor combinations are the core of the system measurement function. Each group of sensors adopts the sensor end mechanical structure in Embodiment 1 above, that is, each group of sensors includes two servos and one ultrasonic sensor. The two servos are used to achieve up and down pitching and left and right swinging to adjust the transceiver plane orientation of the ultrasonic sensor, and then emit ultrasonic waves and receive echo signals in a fixed direction. Finally, the time difference from the emission of the ultrasonic wave to the reception of the echo is obtained. This measurement result will be fed back to the microcontroller in the form of a pulse signal, and the high-level pulse width of the pulse signal is the measured time difference. The installation positions of these 4 groups of sensors can refer to Embodiment 2.

[0145] Figure 6 Shown is the block diagram of the hardware architecture in the measurement system, which shows how each part of the hardware except the microcontroller (MCU) communicates with the signal processing module in the microcontroller. In the microcontroller, the General-Purpose Input / Output (GPIO) module is responsible for outputting the measurement trigger signals for the four groups of sensor combinations and the enable signal for the active buzzer. The Timer (TIMER) module is responsible for outputting the angle control signals for the servos, capturing the measurement result pulse signals of the four groups of sensor combinations and calculating their high-level pulse widths. The Universal Asynchronous Receiver / Transmitter (UART) module is responsible for data interaction with the touch liquid crystal screen and transmitting the operation feedback information to the Bluetooth wireless module. The Inter-Integrated Circuit (IIC) module is responsible for updating the display content of the small dot matrix liquid crystal screen. The Secure Digital Input / Output (SDIO) module is responsible for the read and write operations of the external memory. Figure 6 The arrows in the figure represent the transmission directions on a single signal line, which can be unidirectional output from the microcontroller, unidirectional output from the remaining hardware, or two-way interaction between the microcontroller and the remaining hardware, a total of three forms. All the thin lines represent the connections between single pins; the only wide arrow represents the connection between the four parallel data transmission pins in the part where the microcontroller interacts with the external memory.

[0146] It should be added that Figure 6All the hardware components need to be connected to a common ground and can be uniformly powered by 5V DC power supply. After measurement, the maximum power of the entire system under full load is approximately 9.2W, and the average power is approximately 8.4W; when converted to the current under 5V, they are 1.84A at peak and 1.68A on average respectively. Therefore, when selecting a power adapter or mobile power supply for this system, a power supply with an output power of not less than 10W can be used, that is, the continuous power supply capacity under 5V DC is not less than 2A, to ensure the normal operation of each function of the system.

[0147] Considering the development of semiconductor technology and large-scale integrated circuits, microcontrollers with characteristics such as low cost, low power consumption, and miniaturization have sufficient performance and computing power to serve as the central unit of the above measurement system.

[0148] Example 5——

[0149] The present invention also provides a method for calculating the ultrasonic trajectory through the grid in a three-dimensional space, which can calculate the grid through distance of the ultrasonic trajectory in space. Regarding the software part of the measurement and control system included in the above embodiments of the present invention, the details involved in this method are as Figure 7 、 Figure 8 shown:

[0150] Taking a cuboid room as an example, its three-dimensional spatial form is as shown in (a) of Figure 7 . After inputting the size data of the room in the human-computer interaction interface, the calculation method will perform a certain approximation process so that the processed size can divide the room completely into several cube-shaped grids; assuming the geometric sizes of the room after approximation are L (length), W (width), and H (height), at this time the room can be completely divided into cubes with an edge length of l 0 , then the total number of grids divided can be calculated as If a spatial rectangular coordinate system Oxyz is established according to the method shown in (a) of Figure 7 and the grids are numbered in a certain order, then the geometric center point coordinates of the jth (1≤j≤n) grid can be determined as C j (x grid-j ,y grid-j ,z grid-j ), and the coordinates of the total 8 vertices of this grid are as shown in (b) of Figure 7 .

[0151] According to the preset installation positions of different sensing units, and in each sensing unit, the stepping angle Δθ of the first servo (for adjusting the pitch angle) 1 , and the stepping angle Δθ of the second servo (for adjusting the azimuth angle) 2, determine all m ultrasonic trajectories, and sequentially number all ultrasonic trajectories with i (1 ≤ i ≤ m). Figure 7 Figure (a) in Figure 7 also shows a transceiver integrated ultrasonic sensor S fixedly installed at a certain position in the room A , and its installation coordinates can also be determined as S according to the established rectangular coordinate system A (x A , y A , z A ); and by projecting a certain trajectory emitted by the sensor S in Figure 7 Figure (a) in Figure 7 , as shown in A (c) in Figure 7 , the deflection angle θ Figure 7 of the first servo (for adjusting the pitch angle) can be defined as the angle formed by the projection of the trajectory on the yOz plane and the positive direction of the z-axis, and the deflection angle θ 1 of the second servo (for adjusting the azimuth angle) can be defined as the angle formed by the projection of the trajectory on the xOy plane and the positive direction of the x-axis. 2

[0152] Since directly calculating the three-dimensional space is too complex, for any ultrasonic trajectory emitted by any sensor, it will be converted into a two-dimensional problem for processing by projection. If it is necessary to solve the grid path of the ultrasonic trajectory, the key lies in determining whether the ultrasonic trajectory passes through a certain grid; taking a certain part of the grid in the two-dimensional plane (obtained after projecting the example trajectory) as an example, Figure 8 Figure (a) in Figure 8 shows the basis for judging that the example trajectory passes through the upper left grid, Figure 8 and Figure (b) in Figure 8 shows the basis for judging that the example trajectory does not pass through the lower right grid. If a rectangular coordinate system xOy is established in the illustrated two-dimensional plane, then according to the known starting point coordinates (x 0 , y 0 ) and the inclination angle of the straight line trajectory, the equation of the straight line trajectory can be calculated; combined with the known vertex coordinates P 1 , P 2 , P 3 , P 4 of the target grid P k = (x P-k , y P-k ) (1 ≤ k ≤ 4), the foot of the perpendicular Q 1 , Q 2 , Q 3 , Q 4 coordinates Q j = (x Q-k , y Q-k ) (1 ≤ k ≤ 4) of the line segments starting from these vertices and perpendicular to the straight line trajectory can be calculated, and vectors can be constructed with these line segments such asFigure 8 As shown in (a) in the figure, if the vector If any set of opposite directions appears in , the straight line trajectory is considered to pass through the target grid; Figure 8 As shown in (b) in the figure, if all vectors The directions are consistent, then it is considered that the straight line trajectory does not pass through the target grid. All four vectors are perpendicular to the straight line trajectory and are collinear in the plane, so when calculating, we only need to calculate In the above example, select any non-zero vector with a non-zero dimension (i.e. x k (≠0) or y k (≠0)) as the denominator, and use the coordinates of the other three vectors of the same dimension (which must be consistent with the dimension of the denominator) as the numerator, and calculate the three ratios. Then, we can judge whether the straight line trajectory passes through the target grid based on the calculation results. If all the ratios are non-negative (if the trajectory passes through the grid vertex, then There will be a zero vector, which is considered to be in the same direction as any non-zero vector), then all vectors The directions are consistent, corresponding Figure 8 The trajectory in (a) passes through the upper left corner grid; if any ratio is negative, it means that there is a situation in the opposite direction, corresponding to Figure 8 The trajectory in (b) does not pass through the lower right corner grid. According to the two-dimensional plane, all vectors Since they are all perpendicular to the straight line trajectory, the judgment algorithm is named as the judgment algorithm based on the vertical vector.

[0153] In the right Figure 7 (a) Sensor S A When solving a certain trajectory of the emission, the first two-dimensional processing is performed, and it is projected onto the xOy plane from a top-down perspective, such as Figure 8 As shown in (c) in the figure. At this time, the trajectory in the three-dimensional space degenerates into the two-dimensional xOy plane, which is the trajectory passing through the transmitter installation point (x A ,y A ), tilt angle (according to the definition of plane geometry) a straight line; and the grid in three-dimensional space also degenerates into the situation of two-dimensional xOy plane, that is, all grids with the center point at the same z coordinate become (x grid ,y grid ) as the center, with l 0 The square grid has a side length of , and the coordinates of its four vertices can be calculated as Through the above-mentioned judgment algorithm based on vertical vector, Figure 8As shown in (c) therein, calculate all the grids passed by the trajectory projection in the two-dimensional plane, and incorporate their central coordinates (x grid , y grid ) into the set H xOy {(x grid , y grid ), l xOy}; for a grid passed by the trajectory projection, according to the equation of the projected line and the vertex coordinates of the grid , the coordinates (x 1 , y 1 ) and (x 2 , y 2 ) of the two intersections of the projected line and the grid boundary can also be calculated. According to these two coordinates, when the trajectory is projected onto the xOy plane, the "projection distance" passing through this grid can be calculated, that is, the remaining parameter in the set H xOy As shown in (c) of such as Figure 8 . It should be noted that in the said set H xOy , for the same emission trajectory, the central coordinates (x grid , y grid ) of the square grid passed by its projection and the "projection distance" l xOy of the trajectory in this grid have a strict corresponding relationship, which should be particularly noted when designing the solution method.

[0154] After completing the first two-dimensional processing, the second two-dimensional processing is still required, and it is projected onto the yOz plane according to the perspective of the right view, as Figure 8 shown in (d). At this time, the trajectory in the three-dimensional space degenerates into the situation of the two-dimensional yOz plane, which is a straight line passing through the emitter installation point (y A , z A ) and having an inclination angle (according to the definition of plane geometry); and the grid in the three-dimensional space also degenerates into the situation of the two-dimensional yOz plane, that is, all the grids with the same x coordinate at the center become square grids centered on (y grid , z grid ) with side length l 0 , and the coordinates of its 4 vertices can be calculated as Through the foregoing judgment algorithm based on the vertical vector, as Figure 8 shown in (d), calculate all the grids passed by the trajectory projection in the two-dimensional plane, and incorporate their central coordinates (y grid , z grid ) into the set H yOz {(y grid , z grid ), lΔz in; for a grid through which the trajectory projection passes, according to the equation of the projected straight line and the vertex coordinates of the grid the coordinates of the two intersection points of the projected straight line and the grid boundary can also be calculated (y 1 , z 1 ) and (y 2 , z 2 ). According to these two coordinates, when the trajectory is projected onto the yOz plane, the "longitudinal height difference" passing through this grid can be calculated, that is, the remaining parameter l in the set H zOy = |z Δz - z 2 |, as shown in (d) of 1 . Similarly, it should be noted that in the set H Figure 8 , for the same emission trajectory, the central coordinates (y yOz , z grid ) of the square grid passed through by its projection, and the "longitudinal height difference" l of the trajectory in this grid grid also have a strict corresponding relationship, which especially needs to be noted when designing the solution method. Δz

[0155] By performing two-dimensionalization processing on the trajectory in three-dimensional space, the result set H xOy {(x grid , y grid ), l xOy} projected onto the xOy plane and the result set H yOz {(y grid , z grid ), l Δz} projected onto the yOz plane can be obtained. It can be seen that the coordinate items (x xOy , y grid ) in the set H grid and the coordinate items (y zOy , z grid ) in the set H grid both contain the y-axis coordinate. Therefore, by screening out all the coordinate items with the same y value in the two sets, the set H Oxyz {(x pass-j , y pass-j , z pass-j ), l j} of all the cube grids passed through by this trajectory in three-dimensional space can be constructed. In the set H Oxyz , the coordinate item (x pass-j , y pass-j , z pass-j ) is the central coordinate of the cube grid passed through by the trajectory, and l j ​Indicates the spatial distance when the trajectory passes through the grid, and the subscript j (1 ≤ j ≤ n) represents the grid number. Set H Oxyz The coordinate items (x pass-j , y pass-j , z pass-j ) in the set are composed of the coordinate items (x xOy ) in set H grid , y grid ), and the coordinate items (y zOy , z grid ) in set H grid after screening and combination. Each coordinate item (x xOy , y grid ) in set H grid strictly corresponds to a "projection distance" l xOy . Each coordinate item (y zOy , z grid ) in set H grid strictly corresponds to a "longitudinal height difference" l Δz . And as shown in (e) of Figure 8 , when the trajectory passes through the cube grid in three-dimensional space, the "projection distance" l xOy and the "longitudinal height difference" l Δz are perpendicular in space. At the same time, the two and the part of the trajectory passing through the grid form a right triangle. Therefore, the spatial distance calculation formula can be obtained as . This also shows that the spatial distance item l Oxyz in set H j also has a strict correspondence with the coordinate items (x pass-j , y pass-j , z pass-j ) therein.

[0156] As an important module of the data calculation function in the measurement and control system, the above-mentioned grid passing method for calculating the ultrasonic trajectory as shown in Figure 7 , Figure 8 is also an algorithm for constructing the coefficient matrix S m×n C n×1 = T m×1 in the linear equation system S m×n during the reconstruction of the spatial temperature field. First, approximate the three-dimensional space form to obtain cube grids. Put all 4 integrated ultrasonic sensors into use. By changing the deflection angle step value Δθ 1 of the first servo motor (used to adjust the pitch angle) and the deflection angle step value Δθ 2 of the second servo motor (used to adjust the direction angle), if the 180-degree rotation range is divided by Δθ 1and Δθ 2 are both integers, then at most ultrasonic trajectories can be obtained. If appropriate Δθ 1 and Δθ 2 (both divisible by 180 degrees) are selected such that the total number of trajectories m is not less than twice the number of grids n (i.e., m ≥ 2n), and it is ensured that at least two ultrasonic trajectories pass through each cube grid, then a good spatial temperature field reconstruction effect can be obtained; after processing all m ultrasonic trajectories and n grids through the above-mentioned method of determining the grids passed by the ultrasonic trajectories, the distance s ij passed by each trajectory numbered i (1 ≤ i ≤ m) in each grid numbered j (1 ≤ j ≤ n) is obtained in sequence, and a full-rank coefficient matrix S = [s ij can be constructed m×n , thus providing the numerical conditions for solving the linear equation system S m×n C n×1 = T m×1 using the least squares method.

[0157] Example 6 ——

[0158] The present invention also provides a measurement data correction method for cooperating with the above-mentioned three-dimensional temperature field sensing unit, which is used to process the original time data measured by the ultrasonic sensing unit and output the corrected original data. Regarding the software part of the measurement control system included in the above-mentioned embodiments of the present invention, the details and actual effects involved in this method are as Figure 9 , Figure 10 shown:

[0159] Since a transceiver-integrated ultrasonic sensor is used in the present invention and measurements need to be made by receiving the echoes from the wall surface, in addition to the most ideal condition of transmitting ultrasonic signals perpendicular to the wall surface, when signals are transmitted at different angles deviating from the perpendicular to the wall surface, the direction of the wall's reflection of the echo signal will also deviate from the direction of the sensor receiving the echo signal, thus introducing additional errors during the measurement time. The method for correcting this error is to conduct experiments by changing the angle between the transmitted signal and the wall, compare the ratio of the actual value to the measured value at different angles between the transmitted signal and the wall, and summarize several groups of formulas with the angle between the transmitted signal and the wall as the independent variable, so that in subsequent practical applications, corrections can be made according to different angles between the transmitted signal and the wall.

[0160] First, the concept of "angle between the transmitted signal and the wall" needs to be defined. As Figure 9As shown in (a) in the figure, in three-dimensional space, the installation position of the ultrasonic sensor is denoted as S, and a certain ultrasonic trajectory emitted from point S is denoted as t; after the ultrasonic signal travels a certain distance along the trajectory t, it will touch a certain wall and be reflected. The wall of the reflected echo signal is called the "contact wall", represented by the symbol ρ, and the intersection of the trajectory t and the contact wall ρ is denoted by P t Indicates; then from the installation position point S of the ultrasonic sensor, draw a perpendicular line perpendicular to the contact wall surface ρ, and intersect the contact wall surface ρ at the foot point P S According to the above relationship, if Figure 9 As shown in (b), the three points S, P in the three-dimensional space t , P S , together constitute the SP t The right triangle ΔSP is the hypotenuse t P S ; and from the relevant knowledge in solid geometry, we know that ΔSP t P S The angle ∠SP t P S , which is the line-surface angle between the straight line where the ultrasonic trajectory t lies and the contact wall surface ρ, represented by the symbol β; and the definition of "angle to the wall" is the complementary angle of the line-surface angle β (with its sum being 90°), that is, ΔSP t P S The angle ∠P t SP S , represented by the symbol α. In practical applications, Figure 9 As shown in (a) in the figure, first determine the contact wall surface ρ of the trajectory t in the three-dimensional space based on the sensor installation position S and the trajectory t it transmits, and then find the trajectory intersection point P t and the foot point P S ; After determining the three points S, P t , P S After the position of Figure 9 The right triangle ΔSP shown in (b) t P S , and calculate ΔSP t P S The length of the two right-angled sides and According to the mathematical relationship of the angle α to the wall Find the specific value of α. The special case that needs to be explained is that when When the trajectory intersection point P t and the foot point P SCoincide. At this time, the straight line where the ultrasonic trajectory t is located forms a linear surface angle β of 90° with the contact wall surface ρ, which is the most ideal working condition for "vertically emitting ultrasonic signals directly facing the wall surface"; since the wall angle α and the linear surface angle β are complementary (their sum is 90°), the wall angle α is 0° at this time.

[0161] For the transceiver integrated ultrasonic sensor in the present invention, the upper limit of the wall angle during the measurement process is α ≤ 75°; within the range of the wall angle 0° ≤ α ≤ 75°, the error correction formula c(α) with α as the independent variable has the same form, that is, it can all be expressed as a quadratic polynomial in the form of c(α) = ax 2 + bx + c, and the specific values of the parameters a, b, and c are affected by two factors. One of the influencing factors is the stepping angle Δθ of the servo motor. Since the emission direction of the ultrasonic trajectory is jointly controlled by two servo motors in each sensing unit, and the smaller the value of the servo motor stepping angle, the greater the influence on the error correction formula. Therefore, take the Δθ 1 of the first servo motor (used to adjust the pitch angle) 2 and the Δθ 1 of the second servo motor (used to adjust the azimuth angle) 2 and take the smaller value, that is, Δθ = min{Δθ 1 (α) and c 2 (α). Denote the set of error correction formulas c 1 (α) and c 2 (α) obtained based on the smaller servo motor stepping angle Δθ as The value range of the independent variable α is If the original measurement data is obtained based on the wall angle α, the first servo motor angle of Δθ 1 and the first servo motor angle of Δθ 2 , first take the smaller servo motor stepping angle Δθ = min{Δθ 1 , Δθ 2}, then the original measurement data can be denoted as m(α, Δθ), the data output after correction using the formula is denoted as o(α, Δθ), and then correct and output according to the mathematical relationship o(α, Δθ) = c Δθ (α)m(α, Δθ).

[0162] For different ranges of the smaller servo motor stepping angle Δθ, the error correction formula c Δθ(α), after experimental measurement and data summary, the specific values of the three groups of formulas are obtained as follows (when calculating c Δθ (α), α participates in the calculation in degrees (°)):

[0163] ——When 1° ≤ Δθ ≤ 2°, then ——When 2° < Δθ < 4°, then

[0164] ——When Δθ ≥ 4°, then

[0165] Since the transceiver integrated ultrasonic sensor in the present invention has an included angle range of 0° ≤ α ≤ 75° with the wall during measurement, when dividing the grid for the measured three-dimensional space area, it is necessary to note that the grid cannot be divided too densely, that is, the edge length of the cube grid cannot be too small, otherwise, a small number of grids with a large spatial distance from the sensor will not be covered by the ultrasonic emission trajectory, thus having an adverse impact on the measurement and calculation of the spatial temperature field. As Figure 9 shown in (c) of, at this time, the included angle α of the ultrasonic trajectory t with the wall has reached the critical value of 75°, and the cube grid G in the corner is the grid with the largest spatial distance from the installation position of the sensor S; but the intersection point P t of the straight line where the ultrasonic trajectory t is located and the contact wall surface ρ Figure 9 cannot fall within the grid G, which also shows that Figure 9 the grid division method in (c) has problems, that is, a small number of grids cannot be covered by the ultrasonic trajectory emitted by the sensor S. The way to solve this problem is as shown in Figure 9 the situation shown in (d) of, that is, dividing the grid more sparsely, that is, increasing the edge length of the cube grid; at this time, the included angle α of the ultrasonic trajectory t with the wall is still at the critical value of 75°, but the intersection point P t of the straight line where the ultrasonic trajectory t is located and the contact wall surface ρ Figure 9 can fall within the cube grid G in the corner, that is, the ultrasonic trajectory emitted by the sensor S can cover the grid with the farthest spatial distance from it, which also shows that Figure 9 the grid division method shown in (d) is more reasonable.

[0166] After obtaining the error correction formula c Δθ (α) with the included angle α with the wall as the independent variable, place one ultrasonic sensing unit in an indoor space with a constant temperature. At this time, the air sound speed everywhere in this space is a constant value; use this ultrasonic sensing unit for measurement, and the time measurement results before and after using the correction formula can be obtained under different included angles α with the wall and different small servo stepping angles Δθ. Figure 10In (a), when the servo stepping angles are relatively small, i.e., Δθ = 1.5°, Δθ = 2.5°, and Δθ = 5°, and under several different typical wall angles α, the time measurement results without using the correction formula are compared with the theoretical values. It can be seen that the larger the wall angle α, the more obvious the relative error of the measurement results (exceeding 10% or even 20%); and Figure 10 in (b), the output time measurement results after using the correction formula are shown. It can be seen that under several different typical wall angles α, compared with Figure 10 the situation in (a) without using the correction formula, Figure 10 the relative errors of the measurement results in (b) are effectively controlled (all within 10%), which verifies that the error correction formula can effectively improve the time measurement accuracy of the ultrasonic sensing unit.

[0167] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional temperature field sensing unit, characterized in that: It comprises a sensor mounting bracket (5), an ultrasonic sensor (6), a first steering gear mounting bracket (1-1), a first 180-degree angle steering gear (2-1), a first steering gear rotor (3-1), a second steering gear mounting bracket (1-2), a second 180-degree angle steering gear (2-2), and a second steering gear rotor (3-2), wherein: The first 180-degree angle steering gear (2-1) is mounted on the first steering gear mounting bracket (1-1); the output shaft of the first 180-degree angle steering gear (2-1) is connected to the first steering gear rotor (3-1); the first steering gear rotor (3-1) is fixedly connected to the connecting member, and the connecting member can be driven by the first steering gear rotor (3-1) to rotate 180 degrees under the drive of the first 180-degree angle steering gear (2-1); The second steering gear mounting bracket (1-2) is fixedly connected to the connecting piece; the second 180-degree angle steering gear (2-2) is mounted on the second steering gear mounting bracket (1-2); the output shaft of the second 180-degree angle steering gear (2-2) is connected to the second steering gear rotor (3-2); the output shaft of the first 180-degree angle steering gear (2-1) is perpendicular or skewed to the output shaft of the second 180-degree angle steering gear (2-2); the second steering gear rotor (3-2) is fixedly connected to the sensor mounting bracket (5), and can drive the sensor mounting bracket (5) to rotate 180 degrees through the second steering gear rotor (3-2) under the drive of the second 180-degree angle steering gear (2-2); The ultrasonic sensor (6) is fixed on the sensor mounting bracket (5). The ultrasonic sensor (6) is an integrated transceiver ultrasonic sensor, and the transmitting port and the receiving port are located on the same surface (S1) of the sensor mounting bracket (5).

2. The three-dimensional temperature field sensing unit according to claim 1, characterized in that: The connecting piece is a U-shaped bracket (4); The first steering gear rotor (3-1) is fixedly connected to the bottom surface of the U-shaped bracket (4), and can drive the U-shaped bracket (4) to rotate 180 degrees through the first steering gear rotor (3-1) under the drive of the first 180-degree steering gear (2-1); The second steering gear mounting bracket (1-2) is inserted and mounted in the U-shaped bracket (4).

3. The three-dimensional temperature field sensing unit according to claim 1, characterized in that: The surface of the first 180-degree angle servo (2-1) opposite to the first servo rotor (3-1) is defined as the bottom surface (S2) of the first 180-degree angle servo (2-1), and is also defined as the back surface (S2) of the entire sensing unit; The distance between the rotation axis of the second steering gear rotor (3-2) and the bottom surface (S2) of the first 180-degree steering gear (2-1) is no more than 6 cm.

4. The three-dimensional temperature field sensing unit according to claim 1, characterized in that: The three-dimensional temperature field sensing units can be arranged in the form of any combination of two, facing each other or back to back in space; If two three-dimensional temperature field sensing units are arranged relative to each other in space, the output axes of the first 180-degree servos (2-1) of the two units are collinear and highly consistent in space, the back surfaces (S2) of the two sensing units are not directed toward each other, and within the rotation range, the ultrasonic emission paths emitted by the two ultrasonic sensors (6) must overlap in coverage areas in space; If two three-dimensional temperature field sensing units are arranged back to back in space, the output axes of the first 180-degree servos (2-1) of the two units are collinear and highly consistent in space, but the back surfaces (S2) of the two sensing units are both directed toward each other, and within the rotation range, the coverage areas of the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two units in space will not cross or overlap.

5. A three-dimensional temperature field sensing device, used for three-dimensional temperature field sensing of a measured space of equal height, characterized in that: The device comprises four three-dimensional temperature field sensing units as claimed in any one of claims 1 to 4, and the four three-dimensional temperature field sensing units are respectively referred to as S A , S B , S C , S D ,in, S A and S B Set relatively on a set of opposite side walls in the space, S A , S B The projections on the horizontal plane of the space overlap with the midpoints of the horizontal projection line segments of the two side walls respectively, the output axes of the first 180-degree servos (2-1) of the two are collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap within the rotation range; S C and S D Set on another set of opposite side walls in the space, S C , S D The projections on the horizontal plane of the space overlap with the midpoints of the horizontal projection line segments of the two side walls respectively, the output axes of the first 180-degree servos (2-1) of the two are collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap within the rotation range; S A The output shaft of the first 180 degree servo (2-1) is connected to S C The output shafts of the first 180-degree servo (2-1) are perpendicular to each other in space; S A and S B The connection line with S C and S D The lines of S are highly consistent in space and intersect vertically; A and S B The projection of the line connecting the two on the horizontal plane is the first line, S C and S D The projection of the line connecting the first and second lines on the horizontal plane is the second line, then, the rectangle constructed by the first and second lines can completely cover the projection of the space on the horizontal plane; one side of the rectangle is parallel to the first line, and the other side is parallel to the second line.

6. A three-dimensional temperature field sensing device, used for three-dimensional temperature field sensing of a measured space of equal height, characterized in that: The device comprises four three-dimensional temperature field sensing units as claimed in any one of claims 1 to 4, and the four three-dimensional temperature field sensing units are respectively referred to as S A , S B , S C , S D ,in, (i) If the projected boundary of the measured space on the horizontal plane is a rectangle: S A and S B Set relatively on a set of opposite side walls in the space, S A , S B The projections on the horizontal plane of the space overlap with the midpoints of the horizontal projection line segments of the two side walls respectively, the output axes of the first 180-degree servos (2-1) of the two are collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap within the rotation range; S C and S D The two devices are arranged back to back at the geometric center of the space, the output axes of the first 180-degree servos (2-1) of the two devices are collinear and highly consistent in space, and within the rotation range, the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) do not overlap; S A The output shaft of the first 180 degree servo (2-1) is connected to S C The output shafts of the first 180-degree servo (2-1) are perpendicular to each other in space; S A and S B The connection line with S C and S D The lines connecting the two are highly consistent in space and intersect vertically; (ii) If the projected boundary shape of the measured space on the horizontal plane is a T-shape formed by two rectangles overlapping and intersecting edge to edge: The space where two rectangles overlap is called the common space. The projection of the common space on the horizontal plane is a rectangle. The three sides of the rectangle are within the projection area of ​​the measured space on the horizontal plane, and one side overlaps with the projection boundary of the measured space on the horizontal plane. S A and S B are arranged on a set of opposite side walls in the space, wherein S A The projection of the space on the horizontal plane is on the only edge in the shared space that overlaps with the projection boundary of the measured space on the horizontal plane, and S A , S B The projections on the horizontal plane of the space overlap with the midpoints of the horizontal projection line segments of the two side walls respectively, the output axes of the first 180-degree servos (2-1) of the two are collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap within the rotation range; S C and S D The two devices are arranged back to back at the geometric center of the shared space, the output axes of the first 180-degree servos (2-1) of the two devices are collinear and highly consistent in space, and within the rotation range, the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) do not overlap; S A The output shaft of the first 180 degree servo (2-1) is connected to S C The output shafts of the first 180-degree servo (2-1) are perpendicular to each other in space; S A and S B The connection line with S C and S D The lines connecting the two are highly consistent in space and intersect vertically; (iii) If the projected boundary shape of the measured space on the horizontal plane is an L-shape formed by the overlapping and intersecting sides of two rectangles: The space where two rectangles overlap is called the common space. The projection of the common space on the horizontal plane is a rectangle. Then two adjacent sides of the rectangle are within the projection area of ​​the measured space on the horizontal plane, and the other two adjacent sides overlap with the projection boundary of the measured space on the horizontal plane. In the rectangular projection of the shared space on the horizontal plane, there are two adjacent edges that overlap with the projection boundary of the measured space on the horizontal plane, S A , S B The projections on the horizontal plane are respectively set on the two adjacent edges and overlap with the midpoints of the two adjacent edges; S C and S D The two devices are arranged back to back at the geometric center of the shared space, the output axes of the first 180-degree servos (2-1) of the two devices are collinear and highly consistent in space, and within the rotation range, the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) do not overlap; S A The output shaft of the first 180 degree servo (2-1) is connected to S B The output shafts of the first 180-degree servo (2-1) are highly consistent in space and intersect vertically, with the intersection point being S C and S D The midpoint of the line connecting C and S D The connection height is consistent; In the horizontal projection rectangle of the shared space, there are two adjacent sides that overlap with the projection boundary of the measured space on the horizontal plane, and these two adjacent sides can be combined with a rectangular diagonal line in the horizontal projection rectangle of the shared space to form a right triangle, then S C and S D The projection of the line connecting the two on the horizontal plane coincides with the hypotenuse of the right triangle.

7. A three-dimensional temperature field sensing device, used for three-dimensional temperature field sensing of a measured space of equal height, characterized in that: The device comprises four three-dimensional temperature field sensing units as claimed in any one of claims 1 to 4, and the four three-dimensional temperature field sensing units are respectively referred to as S A , S B , S C , S D ,in, S A and S B The two devices are arranged back to back at the geometric center of the space, the output axes of the first 180-degree servos (2-1) of the two devices are collinear and highly consistent in space, and within the rotation range, the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) do not overlap; S C and S D Set relatively on a set of opposite side walls in the space, S C and S D The projections on the horizontal plane of the space overlap with the midpoints of the horizontal projection line segments of the two side walls respectively, the output axes of the first 180-degree servos (2-1) of the two are collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the ultrasonic sensors (6) of the two overlap within the rotation range; S A , S B , S C , S D The output shafts of the first 180-degree servos (2-1) of the four are collinear and highly consistent in space. Press S C , S A , S B , S D Arrange in order; At the same time, if the space is located at S A and S B The geometric center interface is divided into two sides, then S C and S A Set opposite to each other on one side, S B and S D Set opposite on the other side.

8. A three-dimensional temperature field sensing device, used for three-dimensional temperature field sensing of a measured space of equal height, characterized in that: The device comprises four three-dimensional temperature field sensing units as claimed in any one of claims 1 to 4, and the four three-dimensional temperature field sensing units are respectively referred to as S A , S B , S C , S D ,in, Divide the space into two equal parts, S A and S B The two devices are arranged at the geometric center of the space on one side, with their first 180-degree angle servos (2-1) output axes being collinear and highly consistent in space, and within the rotation range, the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) do not overlap; S C and S D The two devices are arranged at the geometric center of the space on the other side, with their first 180-degree angle servos (2-1) output axes being collinear and highly consistent in space, and the areas covered by the ultrasonic emission paths emitted by the two ultrasonic sensors (6) within the rotation range do not overlap; S A , S B , S C , S D The output shafts of the first 180-degree servos (2-1) of the four are collinear and highly consistent in space. Press S A , S B , S C , S D Arrange in order; At the same time, S B The area covered by the ultrasonic transmission path emitted by the ultrasonic sensor (6) is the same as S C , S D The areas that can be covered overlap, S C The area covered by the ultrasonic transmission path emitted by the ultrasonic sensor (6) is the same as S B , S A The areas that can be covered overlap, S A and S D Back to setting.

9. A method for calculating the ultrasonic trajectory through a grid in a three-dimensional space, used in conjunction with the three-dimensional temperature field sensing unit as claimed in any one of claims 1 to 4 or the three-dimensional temperature field sensing device as claimed in any one of claims 5 to 8, characterized in that: The following steps are involved: (1) According to the preset shape and geometric size of the three-dimensional space to be measured, the three-dimensional space to be measured is preprocessed and coordinateized using the spatial rectangular coordinate system Oxyz, so that the three-dimensional space to be measured can be completely divided into n cube-shaped grids, and the edge length of each grid is l0; then, the center coordinate C of the jth grid is calculated j (x grid-j ,y grid-j ,z grid-j ) and vertex coordinates (2) according to the installation position of each three-dimensional temperature field sensing unit, and the step angle Δθ1 of the first 180-degree angle servo and the step angle Δθ2 of the second 180-degree angle servo in each three-dimensional temperature field sensing unit, all m ultrasonic trajectories are determined, m>n; preferably, m≥2n; (3) From a bird's-eye view, perform a two-dimensional plane projection on each ultrasonic trajectory to present it in a grid in the xOy plane. Then calculate the perpendicular vectors from the four vertices of each grid in the plane to the straight line obtained by projecting the ultrasonic trajectory. If the directions of the four perpendicular vectors of a certain grid are not completely consistent, it means that the straight line obtained by projecting the ultrasonic trajectory passes through this grid in the xOy plane, thereby determining the x- and y-dimensional coordinates (x , y ) of the center point of the grid passed by the ultrasonic trajectory in space. grid ,y grid ); If it is determined that in the xOy plane, the straight line obtained by projecting a certain ultrasonic trajectory passes through the center point (x grid ,y grid ), then according to the coordinates of the four vertices of the mesh Calculate the coordinates of the two intersection points (x1, y1) and (x2, y2) of the straight line projected by this ultrasonic trajectory and the grid boundary, and then calculate the projection distance of this ultrasonic trajectory through the grid when projected into the xOy plane. And project the same ultrasonic trajectory onto the straight line in the xOy plane, and establish each straight line passing through the grid center point coordinates (x grid ,y grid ) and the projection distance l through the grid xOy One-to-one correspondence between , constitutes a set of xOy plane projection calculation results set H xOy {(x grid ,y grid ),l xOy }; From the right side of the view, a two-dimensional plane projection is performed on each ultrasonic trajectory to present it in a grid in the yOz plane. Then, the four vertices of each grid in the plane are calculated one by one, and the perpendicular vectors to the straight line obtained by the ultrasonic trajectory projection are calculated. If the directions of the four perpendicular vectors of a certain grid are not completely consistent, it means that the straight line obtained by the ultrasonic trajectory projection passes through this grid in the yOz plane, thereby determining the y- and z-dimensional coordinates (y grid ,z grid ); If it is determined that the straight line obtained by projecting a certain ultrasonic trajectory in the yOz plane passes through the center point (y grid ,z grid ), then according to the coordinates of the four vertices of the mesh The coordinates of the two intersection points (y1, z1) and (y2, z2) of the straight line projected by the ultrasonic trajectory and the grid boundary can be calculated, and then the longitudinal height difference l of the ultrasonic trajectory through the grid when projected into the yOz plane can be calculated. Δz =|z2-z1|, and project the same ultrasonic trajectory onto the straight line in the yOz plane to establish each straight line passing through the grid center coordinates (y grid ,z grid ) and the vertical height difference l through the grid Δz One-to-one correspondence between yOz and yOz constitutes a set of yOz plane projection calculation results set H yOz {(y grid ,z grid ),l Δz }; For an ultrasonic trajectory, two sets of calculation results H are obtained after two projections. xOy {(x grid ,y grid ),l xOy } and H yOz {(y grid ,z grid ),l Δz }, filter out the two-dimensional coordinate items with the same y dimension, and then use (x grid ,y grid ) and (y grid ,z grid ) constructs the ultrasonic trajectory, and the coordinates of the center points of all cube grids that it passes through in three-dimensional space (x pass-j ,y pass-j ,z pass-j ), and then according to the two-dimensional coordinate item (x grid ,y grid ) and (y grid ,z grid ), the corresponding projection distance l xOy And the longitudinal height difference l Δz , calculate the spatial distance of the ultrasonic trajectory through a certain cube grid And combine the coordinates of all the cube grid center points (x pass-j ,y pass-j ,z pass-j ), and the spatial distance l j , establish a one-to-one correspondence relationship, and form a set of spatial Oxyz calculation results of a set of ultrasonic trajectories H Oxyz {(x pass-j ,y pass-j ,z pass-j ),l j }; (4) All m ultrasonic trajectories are sequentially brought into n cube grids for calculation, that is, first determine whether each ultrasonic trajectory passes through all n grids; if not, the spatial distance of the corresponding grid is counted as 0; if it passes, the spatial distance of the corresponding grid is calculated again, thereby obtaining m sets of spatial Oxyz calculation result sets H Oxyz {(x pass-j ,y pass-j ,z pass-j ),l j }, the trajectory of the ultrasonic wave passing through the grid in the three-dimensional space can be solved; among which, for the i-th ultrasonic wave trajectory, its trajectory through the grid is the total spatial distance passed through all n grids, including distance 0 and distance non-zero, 1≤i≤m.

10. A method for correcting measurement data used in conjunction with the three-dimensional temperature field sensing unit according to any one of claims 1 to 4 or the three-dimensional temperature field sensing device according to any one of claims 5 to 8, characterized in that: The following steps are involved: According to the installation position S of the ultrasonic sensing unit, the first steering gear angle θ1, and the second steering gear angle θ2, the straight line of a certain ultrasonic trajectory t emitted by the sensing unit is calculated, and according to the preset three-dimensional spatial form, the wall surface ρ reflecting the ultrasonic trajectory is calculated; According to the spatial relationship between the straight line where the ultrasonic track t is located and the wall surface ρ reflecting the ultrasonic track, the line-surface angle β formed by the two is calculated; at the same time, the complementary angle α of the line-surface angle is defined as the wall angle formed by the straight line where the ultrasonic track t is located and the wall surface ρ reflecting the ultrasonic track, that is, α+β=90°; And the range of the angle α to the wall is 0°≤α≤75°; Then, compare the step angle Δθ1 of the first 180-degree angle servo in the same three-dimensional temperature field sensing unit with the step angle Δθ2 of the second 180-degree angle servo, take the smaller value of the two and record it as Δθ, that is, Δθ=min{Δθ1,Δθ2}; For any ultrasonic trajectory t, with α in degrees, c is calculated as follows: Δθ (α): When 1°≤Δθ≤2°, then, When 2°<Δθ<4°, then, When Δθ≥4°, then, If the original time data measured by the ultrasonic sensing unit is recorded as m(α, Δθ), and the output data after correction is recorded as o(α, Δθ), then: o(α,Δθ)=c Δθ (α)m(α,Δθ).

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