Multi-directional tilt sensor and monitoring system for building structures based on dual patch antennas

Abstract

The present invention belongs to the field of building structure health monitoring, and relates to a multi-directional tilt sensor and monitoring system for building structures based on dual patch antennas. The sensor provided by the present invention can be installed on a building structure to sense the multi-directional tilt of the building structure; the tilt of the building structure in different directions will cause changes in the liquid height in the upper containers of the patch antenna in the X direction and the patch antenna in the Y direction, and further cause changes in electromagnetic parameters such as the resonance frequencies of the patch antenna in the X direction and the patch antenna in the Y direction; by decoupling the changes in the resonance frequencies of the two patch antennas, the tilt direction and degree of the building structure can be determined; the reading device of the monitoring system can wirelessly read the changes in the resonance frequencies of the two patch antennas in different directions of the sensor, so as to realize the wireless monitoring of the multi-directional tilt of the building structure.

Description

Technical Field

[0001] The present invention belongs to the field of building structure health monitoring, and relates to a multi-directional tilt sensor and a monitoring system for building structures based on dual patch antennas. Background Art

[0002] During the long-term use of buildings, due to factors such as uneven settlement, buildings are prone to tilt. The tilt of buildings will cause uneven stress on the structure, and excessive tilt is also extremely likely to cause the overall overturning or damage of the buildings. Therefore, during the entire service life of the building structure, it is necessary to monitor the tilt of the building structure in real time in order to timely understand the service status of the building structure and ensure the safe use of the building structure.

[0003] Currently, there are various types of sensing devices for building tilt monitoring in engineering, such as building structure tilt sensors based on liquid plane level monitoring, fiber optic tilt sensors, gyroscopes and other sensing technologies. These sensors can effectively monitor the tilt of building structures, but currently, the sensors used for building structure tilt monitoring usually can only monitor and sense the tilt of building structures in a certain direction. There are still certain difficulties in using a single tilt sensor to monitor the multi-directional tilt of building structures. In addition, since most current tilt sensors require continuous power supply and use wired methods for signal transmission, this will lead to complex wiring of the monitoring system, time-consuming and laborious installation, and high costs, which limits their application in actual engineering structures to a certain extent. Summary of the Invention

[0004] In order to solve the problems of the tilt sensor requiring wired signal transmission and power supply, and to solve the shortcoming that traditional tilt sensors usually only sense and monitor the tilt of buildings in a single direction, the present invention provides a multi-directional tilt sensor and a monitoring system for building structures based on dual patch antennas, which can be installed in the building structure to realize the monitoring of the multi-directional tilt of the building structure.

[0005] The present invention is realized through the following technical solutions:

[0006] A multi-directional tilt sensor for building structures based on dual patch antennas, wherein the multi-directional tilt sensor for building structures includes Component One and Component Two;

[0007] Component One includes a high-frequency dielectric board (1), a ground plane (2) located on the lower surface of the high-frequency dielectric board (1), an X-direction patch antenna (3), a Y-direction patch antenna (4), a microstrip feeder line (5), and a radio frequency chip (6);

[0008] The X-direction patch antenna (3), the Y-direction patch antenna (4), the microstrip feeder line (5), and the RF chip (6) are all disposed on the upper surface of the high-frequency dielectric board (1); the two patch antennas, namely the X-direction patch antenna (3) and the Y-direction patch antenna (4), are connected to the RF chip (6) through a bifurcated Y-shaped microstrip feeder line (5).

[0009] The second component includes an upper liquid container (7) and a high-dielectric constant liquid (8) contained in the upper liquid container (7).

[0010] The upper liquid container (7) is a cube or a cuboid; the upper liquid container (7) is disposed above the X-direction patch antenna (3) and the Y-direction patch antenna (4), and two sides of the upper liquid container are respectively aligned with the edges of the X-direction patch antenna (3) and the Y-direction patch antenna (4).

[0011] Further, the material of the ground plane (2) is copper.

[0012] The X-direction patch antenna (3) and the Y-direction patch antenna (4) have the same structure, including two layers of metal sheets and an intermediate dielectric layer located between the two layers of metal sheets.

[0013] The X-direction patch antenna (3) and the Y-direction patch antenna (4) are both rectangular.

[0014] The RF chip (6) is soldered to the high-frequency dielectric board (1).

[0015] Further, the length of the X-direction patch antenna (3) in the X-axis direction is L x , and the length of the Y-direction patch antenna (4) in the Y-axis direction is L y , and L x ≠L y .

[0016] Further, the material of the upper liquid container (7) is acrylic, and the upper liquid container (7) is integrally sealed, and there is a high-dielectric constant liquid and air inside the upper liquid container (7).

[0017] Further, when the upper liquid container (7) is placed horizontally, the average height of the high-dielectric constant liquid (8) inside the upper liquid container (7) is h 0 ;

[0018] The length L ab of the side of the upper liquid container (7) in the X-axis direction is greater than the length L x of the X-direction patch antenna (3); and the length Lad Greater than the length L of the Y-direction patch antenna (4) y .

[0019] Furthermore, the first component and the second component of the building structure multi-directional tilt sensor are horizontally installed on the building structure as a whole. When the building structure tilts, the building structure multi-directional tilt sensor tilts in the same way as the building structure, and then the liquid level height of the high-dielectric constant liquid (8) inside the upper liquid container (7) changes;

[0020] By determining the height of the liquid level of the high-dielectric constant liquid (8) inside the upper liquid container (7), the tilt degrees of the building structure in the X and Y directions are determined.

[0021] Furthermore, the calculation method for the tilt degrees of the building structure in the X and Y directions includes:

[0022] S1: Let point a, point b, point c, and point d be the contact points between the four corners of the upper liquid container and the high-frequency dielectric plate, and point a is the intersection point of the extension line of the outer side of the X-direction patch antenna and the extension line of the outer side of the Y-direction patch antenna, point b is on the extension line of the outer side of the X-direction patch antenna, and point d is on the extension line of the outer side of the Y-direction patch antenna;

[0023] S2: By the change in the resonant frequencies of the X-direction patch antenna and the Y-direction patch antenna, the liquid level height h after the building structure tilts is inversely deduced a , h b and h d ;

[0024] h a represents the liquid level height corresponding to the upper part of point a, h b represents the liquid level height corresponding to the upper part of point b, h d represents the liquid level height corresponding to the upper part of point d;

[0025] S3: The tilt degrees of the building structure in the X-axis and Y-axis directions satisfy:

[0026]

[0027] where, α x represents the tilt degree of the building structure in the X-axis direction; α y represents the tilt degree of the building structure in the Y-axis direction; L ab is the length of the side of the upper liquid container in the X-axis direction, L ad is the length of the side of the upper liquid container in the Y-axis direction;

[0028] S4: After vectorially synthesizing the tilt degrees of the building structure in the X-axis and Y-axis directions, the tilt direction and tilt degree sensing within 360° in the plane are realized.

[0029] Further, in step S2, the liquid level h after the building structure is tilted is inferred by the change of the resonant frequency of the patch antenna in the X direction and the patch antenna in the Y direction. a ,h b and h d , specifically including:

[0030] S21: According to the relevant electromagnetic theory, the calculation formula of the resonant frequency of the X-direction patch antenna and the Y-direction patch antenna is expressed as:

[0031]

[0032]

[0033] Among them, f x is the resonant frequency of the patch antenna in the X direction, f y is the resonant frequency of the patch antenna in the Y direction; c is the propagation speed of electromagnetic waves in a vacuum, ε x is the effective dielectric constant of the high-frequency dielectric plate within the range of the patch antenna in the X direction; ε y is the effective dielectric constant of the high-frequency dielectric plate within the Y-direction patch antenna range, ε x and ε y They are all affected by the height of the high dielectric constant liquid in the liquid container covering the patch antenna;

[0034] Among them, ε x and ε y It is expressed as:

[0035]

[0036]

[0037] Among them, ε 0 is the initial dielectric constant of the high-frequency dielectric plate; k is the correlation coefficient between the effective dielectric constant and the height of the high dielectric constant liquid in the liquid container above the patch antenna;

[0038] in,

[0039] h b +h d =2*h 0 (7)

[0040] Then formula (6) can be rewritten as:

[0041]

[0042] Combining equations (3)(4)(5)(8), we can calculate h a and h b ;

[0043] Furthermore, h is calculated by formula (7). d .

[0044] A multi-directional tilt monitoring system for building structures based on dual patch antennas, including the multi-directional tilt sensor for building structures and a reader (9);

[0045] The multi-directional tilt sensor for building structures is installed at the top of the building structure, and the reader (9) is placed in the area near the building to be measured;

[0046] The reader (9) emits a swept-frequency electromagnetic wave to the radio frequency chip (6) in the multi-directional tilt sensor for building structures to activate the radio frequency chip (6);

[0047] After the radio frequency chip (6) is activated, it generates an electric current and emits an electromagnetic wave signal through the patch antenna. After the electromagnetic wave signal is received by the reader (9), data processing is performed to obtain the tilt direction and tilt degree of the building structure.

[0048] Further, the reader (9) includes a wireless transceiver module, a control module, a modulation and demodulation module, and a digital processing module;

[0049] The wireless transceiver module includes transmitting and receiving antennas for transmitting and receiving modulated electromagnetic wave signals of different frequencies to the radio frequency chip in the multi-directional tilt sensor for building structures;

[0050] The modulation and demodulation module is used for modulating and demodulating the electromagnetic wave signals transmitted and received by the wireless transceiver module, and transmitting the data information contained in the electromagnetic wave signals to the control module and the digital processing module; the data information includes the tilt sensor number and the measuring point position;

[0051] The control module is used for controlling the reader to emit modulated electromagnetic wave signals of different frequencies to the tilt sensor, and detecting the threshold activation power of the radio frequency chip in the multi-directional tilt sensor for building structures under the action of electromagnetic waves of different frequencies, and further obtaining the resonant frequency information of the patch antennas in different directions in the sensor;

[0052] The digital processing module calculates the tilt degrees of the building structure in the X direction and the Y direction according to the change amounts of the resonant frequencies of the patch antennas in two different directions of the sensor, and realizes the tilt monitoring of the building structure where the sensor is installed after vector synthesis.

[0053] The beneficial technical effects of the present invention:

[0054] (1) The sensor provided by the present invention is provided with a liquid container and a high dielectric constant liquid on the dual patch antenna. According to the change in the liquid level of the high dielectric constant liquid in the container caused by the tilt of the building structure, the resonant frequency of the dual patch antenna is further changed, so as to realize the monitoring and sensing of the tilt of the building structure.

[0055] (2) The present invention establishes the corresponding relationship between the resonant frequency of the dual patch antenna and the inclination in different directions of the building structure. According to the change and decoupling of the resonant frequency of the dual patch antenna, quantitative characterization of the multi-directional inclination of the building structure can be achieved.

[0056] (3) In the present invention, the sizes of the two patch antennas are designed differently so that their initial resonant frequencies are different, avoiding the phenomenon of frequency band interference during actual use and ensuring the accuracy of monitoring and sensing multi-directional inclination.

[0057] (4) The present invention can realize passive wireless monitoring of the inclination of the building structure. Passive means that the sensing end based on the dual patch antenna does not require energy input through a power source such as a battery, and wireless means that signal transmission does not require cables. The present invention realizes passive wireless inclination monitoring of the building structure through the electromagnetic waves transmitted and received by the reader, avoiding the dependence on power sources and cables of traditional inclination sensors and reducing the monitoring, traditional installation, and wiring costs. Description of the Drawings

[0058] Figure 1 Schematic diagram of Component 1 in the embodiment of the present invention;

[0059] Figure 2 Schematic diagram of Component 2 in the embodiment of the present invention;

[0060] Figure 3 Top view of the multi-directional inclination sensor for building structure based on dual patch antenna in the embodiment of the present invention;

[0061] Figure 4 Schematic diagram of the liquid plane height in the X direction when the building structure inclines in the positive X-axis direction in the embodiment of the present invention;

[0062] Figure 5 Schematic diagram of the liquid plane height in the Y direction when the building structure inclines in the positive X-axis direction in the embodiment of the present invention;

[0063] Figure 6 Schematic diagram of the multi-directional inclination monitoring system for building structure based on dual patch antenna in the embodiment of the present invention. Detailed Embodiments

[0064] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0065] On the contrary, the present invention covers any alternatives, modifications, equivalent methods, and solutions that are defined by the claims and fall within the spirit and scope of the present invention. Further, in order to enable the public to better understand the present invention, in the following detailed description of the present invention, some specific details are described in detail. Those skilled in the art can fully understand the present invention even without the description of these details.

[0066] Embodiment 1: A multi-directional tilt sensor for building structures based on a dual patch antenna, where the multi-directional tilt sensor for building structures includes Component One and Component Two;

[0067] As Figure 1 shown, Component One includes a high-frequency dielectric board 1, a ground plane 2 located on the lower surface of the high-frequency dielectric board 1, an X-direction patch antenna 3, a Y-direction patch antenna 4, a microstrip feeder 5, and a radio frequency chip 6; among them, the radio frequency chip is an RFID radio frequency chip;

[0068] The X-direction patch antenna 3, the Y-direction patch antenna 4, the microstrip feeder 5, and the radio frequency chip 6 are all arranged on the upper surface of the high-frequency dielectric board 1; the two patch antennas, the X-direction patch antenna 3 and the Y-direction patch antenna 4, are connected to the radio frequency chip 6 through a bifurcated Y-shaped microstrip feeder 5; specifically, the X-direction patch antenna 3 is arranged along the X-axis direction, the Y-direction patch antenna 4 is arranged along the Y-axis direction, and the two patch antennas do not touch;

[0069] As Figure 2 shown, Component Two includes an upper liquid container 7 and a high-dielectric-constant liquid 8 contained in the upper liquid container 7;

[0070] The upper liquid container 7 is a cube or a cuboid; the upper liquid container 7 is arranged above the X-direction patch antenna 3 and the Y-direction patch antenna 4, and two sides of the upper liquid container are respectively aligned with the edges of the X-direction patch antenna 3 and the Y-direction patch antenna 4, as Figure 3 shown. Specifically, the upper liquid container 7 is pasted above the X-direction patch antenna 3 and the Y-direction patch antenna 4 with glue to prevent the position of the upper liquid container 7 from changing.

[0071] In this embodiment, the material of the high-frequency dielectric board 1 is an RT5880 high-frequency dielectric board, or a high-frequency dielectric board of RO3010 and FR4 models.

[0072] The material of the ground plane 2 is copper;

[0073] The X-direction patch antenna 3 and the Y-direction patch antenna 4 have the same structure, including two layers of metal sheets and an intermediate dielectric layer located between the two layers of metal sheets;

[0074] Both the X-direction patch antenna 3 and the Y-direction patch antenna 4 are rectangular;

[0075] The radio frequency chip 6 is soldered on the high-frequency dielectric board 1.

[0076] Specifically, the material of the metal sheet in both the X-direction patch antenna 3 and the Y-direction patch antenna 4 is copper; and the material of the intermediate dielectric layer is the same as that of the high-frequency dielectric board 1.

[0077] Specifically, the radio frequency chip 6 is soldered at the corner or end of the high-frequency dielectric board close to the patch antenna, and is connected to the two patch antennas through a bifurcated microstrip transmission line.

[0078] In this embodiment, the length of the X-direction patch antenna 3 in the X-axis direction is L x , and the length of the Y-direction patch antenna 4 in the Y-axis direction is L y , and L x ≠L y .

[0079] L x and L y The preferred lengths of L x can be set to ly = (0.6 - 0.9)L x , preferably ly = 0.8L

[0080] For example, if the length of the X-direction patch antenna is set to 10 cm, the length of the Y-direction patch antenna is set to about 6 - 9 cm, preferably 8 cm. The patch width generally does not exceed 50% of the patch length.

[0081] In this embodiment, when the upper liquid container 7 is placed horizontally, the average height of the high-dielectric constant liquid 8 inside the upper liquid container 7 is h 0 ;

[0082] Preferably, the average height h 0 is set to 40 - 60% of the height of the upper liquid container 7, preferably 50%; at this time, when the average height h 0 is set to 50% of the height of the upper liquid container 7, the tilt angle range that this sensor can measure is ±2*h 0 / L ab (tilt angle range measurable in the X direction) or ±2*h 0 / L ad(The range of tilt angles that can be measured in the Y direction);

[0083] The length L of the upper liquid container 7 on the side in the X-axis direction ab is greater than the length L of the patch antenna 3 in the X direction x ; and the length L of the upper liquid container 7 on the side in the Y-axis direction ad is greater than the length L of the patch antenna 4 in the Y direction y , as Figure 3 shown.

[0084] In this embodiment, the component one and component two of the building structure multi-directional tilt sensor are horizontally installed on the building structure as a whole. When the building structure tilts, the building structure multi-directional tilt sensor tilts in the same way as the building structure, and then the liquid level height of the high-dielectric-constant liquid 8 inside the upper liquid container 7 changes;

[0085] By determining the height of the liquid level of the high-dielectric-constant liquid 8 inside the upper liquid container 7, the tilt degrees of the building structure in the X and Y directions are determined.

[0086] In this embodiment, the calculation method for the tilt degrees of the building structure in the X and Y directions includes:

[0087] S1: Let points a, b, c, and d be the contact points of the four corners of the upper liquid container with the high-frequency dielectric plate, and point a is the intersection point of the extension lines of the outer sides of the patch antenna in the X direction and the extension lines of the outer sides of the patch antenna in the Y direction. Point b is on the extension line of the outer side of the patch antenna in the X direction, and point d is on the extension line of the outer side of the patch antenna in the Y direction;

[0088] S2: By the change in the resonant frequencies of the patch antenna in the X direction and the patch antenna in the Y direction, the liquid level height h after the building structure tilts is deduced a , h b and h d ;

[0089] h a represents the liquid level height corresponding to the upper side of point a, h b represents the liquid level height corresponding to the upper side of point b, h d represents the liquid level height corresponding to the upper side of point d;

[0090] S3: The tilt degrees of the building structure in the X-axis and Y-axis directions satisfy:

[0091]

[0092] where, α x represents the tilt degree of the building structure in the X-axis direction; α y represents the tilt degree of the building structure in the Y-axis direction; L abis the length of the side of the upper liquid container in the X-axis direction, L ad is the length of the side of the upper liquid container in the Y-axis direction;

[0093] S4: After synthesizing the inclination degree vectors of the building structure in the X-axis and Y-axis directions, realize the inclination direction and inclination degree sensing within 360° in the plane. After synthesizing the inclination degree vectors of the building structure in the X-axis and Y-axis directions in this step, the inclination direction and degree of the building structure can be determined. The inclination direction can be any direction within the range of 360° in the plane, so the disadvantage that traditional sensors can only sense the inclination degree in a single direction can be avoided.

[0094] In this embodiment, in step S2, the liquid level height h after the building structure is inclined is deduced by the change of the resonance frequencies of the X-direction patch antenna and the Y-direction patch antenna a , h b and h d , specifically including:

[0095] S21: According to the relevant theory of electromagnetism, the calculation formulas for the resonance frequencies of the X-direction patch antenna and the Y-direction patch antenna are expressed as:

[0096]

[0097] Among them, f x is the resonance frequency of the X-direction patch antenna, f y is the resonance frequency of the Y-direction patch antenna; c is the propagation speed of electromagnetic waves in vacuum, ε x is the effective dielectric constant of the high-frequency dielectric plate within the range of the X-direction patch antenna; ε y is the effective dielectric constant of the high-frequency dielectric plate within the range of the Y-direction patch antenna, ε x and ε y are both affected by the height of the high-dielectric constant liquid in the upper liquid container of the patch antenna;

[0098] Since there is a high-dielectric constant liquid with a dielectric constant much higher than that of air in the upper container of the patch antenna, it will have a certain impact on the effective dielectric constant. According to the relevant theory of electromagnetism, the effective dielectric constants ε x and ε y are correlated with the initial dielectric constant ε 0 and the height of the liquid covering the patch antenna. Let the degree of correlation be k;

[0099] Among them, ε x and ε y are expressed as:

[0100]

[0101] Among them, ε 0is the initial dielectric constant of the high-frequency dielectric plate; k is the correlation coefficient between the effective dielectric constant and the height of the high dielectric constant liquid in the liquid container above the patch antenna. The value of the correlation coefficient k needs to be determined according to the type of high dielectric constant liquid through simulation and experiments.

[0102] Since the liquid in the container is completely sealed, point a and point d are points on the diagonal of the container, so there is always:

[0103] in,

[0104] h b +h d =2*h 0 (7)

[0105] Then formula (6) can be rewritten as:

[0106]

[0107] By combining equations (3), (4), (5), and (8), the two variables, the resonant frequency change of the patch antenna in the X direction and the resonant frequency change of the patch antenna in the Y direction, are decoupled to calculate h a and h b ;

[0108] Then, h is calculated by formula (7): d .

[0109] Embodiment 2: A building structure multi-directional tilt monitoring system based on dual patch antennas, characterized by comprising the building structure multi-directional tilt sensor and reader 9 described in Embodiment 1;

[0110] The building structure multi-directional tilt sensor is installed on the top of the building structure, and the reader 9 is placed in the vicinity of the building to be tested; specifically, the reader 9 is placed at any position in the vicinity of the building to be tested, but care should be taken to avoid large-area metal shielding that affects the transmission of electromagnetic wave signals.

[0111] The reader 9 transmits a frequency sweeping electromagnetic wave to the radio frequency chip 6 in the multi-directional tilt sensor of the building structure to activate the radio frequency chip 6;

[0112] After the radio frequency chip 6 is activated, it generates current and transmits electromagnetic wave signals through the patch antenna. After the electromagnetic wave signals are received and processed by the reader 9, data processing is performed to obtain the tilt direction and tilt degree of the building structure.

[0113] In this embodiment, the reader 9 includes a wireless transceiver module, a control module, a modulation and demodulation module, and a digital processing module;

[0114] The wireless transceiver module includes a transmitting and receiving antenna, which is used to transmit and receive modulated electromagnetic wave signals of different frequencies to the radio frequency chip in the building structure multi-directional tilt sensor;

[0115] Specifically, the wireless transceiver module transmits modulated electromagnetic wave signals of different frequencies to the building structure multi-directional tilt sensor based on dual patch antennas installed on the building structure; the X-direction patch antenna and the Y-direction patch antenna of the sensor are designed with different sizes and have different initial resonance frequencies, so the signals of the two patch antennas can be better distinguished; when the electromagnetic wave signal received by the sensor radio frequency chip 6 corresponds to the resonance frequency of any direction patch antenna, the threshold activation power of the radio frequency chip 6 will be significantly reduced, and the radio frequency chip 6 is activated to work. After the radio frequency chip 6 is activated, it generates current and transmits electromagnetic wave signals carrying sensor number, measuring point position, and patch antenna resonance frequency information through the patch antenna. After the electromagnetic wave signals are received and processed by the reader 9, the number, position of the sensor, and the resonance frequency information of the two different direction patch antennas are obtained;

[0116] The modulation and demodulation module is used to modulate and demodulate the electromagnetic wave signals transmitted and received by the wireless transceiver module, and transfer the data information contained in the electromagnetic wave signals to the control module and the digital processing module; the data information includes tilt sensor number and measuring point position;

[0117] The control module is used to control the reader to transmit modulated electromagnetic wave signals of different frequencies to the tilt sensor, and detect the threshold activation power of the radio frequency chip in the building structure multi-directional tilt sensor under the action of electromagnetic waves of different frequencies, so as to obtain the resonance frequency information of different direction patch antennas in the sensor;

[0118] The digital processing module calculates the tilt degrees of the building structure in the X direction and the Y direction according to the resonance frequency change amounts of the two different direction patch antennas of the sensor, and realizes the tilt monitoring of the building structure where the sensor is installed after vector synthesis. This tilt can be in any direction within the 360° range in the plane.

[0119] The building structure tilt sensor based on dual patch antennas provided by the present invention can be installed on the building structure to realize the sensing of multi-directional tilt of the building structure; the tilt of the building structure in different directions will cause changes in the liquid height in the upper containers of the X-direction patch antenna and the Y-direction patch antenna, and further cause changes in electromagnetic parameters such as the resonance frequencies of the X-direction patch antenna and the Y-direction patch antenna; by decoupling the resonance frequency changes of the two patch antennas, the tilt direction and degree of the building structure can be determined, and this tilt direction can be in any direction within the 360° range in the plane; the reading device of the monitoring system can wirelessly read the resonance frequency changes of the two different direction patch antennas of the sensor, so as to realize the wireless monitoring of the multi-directional tilt of the building structure.

[0120] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A building structure multi-directional tilt sensor based on dual patch antennas, characterized in that: The building structure multi-directional tilt sensor comprises component one and component two; The component 1 comprises a high-frequency dielectric plate (1), a ground plane (2) located on the lower surface of the high-frequency dielectric plate (1), an X-direction patch antenna (3), a Y-direction patch antenna (4), a microstrip feed line (5), and a radio frequency chip (6); The X-direction patch antenna (3), the Y-direction patch antenna (4), the microstrip feed line (5) and the radio frequency chip (6) are all arranged on the upper surface of the high-frequency dielectric plate (1); the X-direction patch antenna (3) and the Y-direction patch antenna (4) are connected to the radio frequency chip (6) via a bifurcated Y-shaped microstrip feed line (5); The second component comprises an overlying liquid container (7) and a high dielectric constant liquid (8) contained in the overlying liquid container (7); The overlying liquid container (7) is a cube or a rectangular parallelepiped; the overlying liquid container (7) is arranged above the X-direction patch antenna (3) and the Y-direction patch antenna (4), and two sides of the overlying liquid container are respectively aligned with the edges of the X-direction patch antenna (3) and the Y-direction patch antenna (4).

2. The building structure multi-directional tilt sensor based on dual patch antenna according to claim 1, characterized in that: The material of the ground plane (2) is copper; The X-direction patch antenna (3) and the Y-direction patch antenna (4) have the same structure, comprising two layers of metal sheets, an upper layer and a lower layer, and an intermediate dielectric layer located between the two layers of metal sheets; The X-direction patch antenna (3) and the Y-direction patch antenna (4) are both rectangular; The radio frequency chip (6) is welded on the high-frequency dielectric plate (1).

3. The building structure multi-directional tilt sensor based on dual patch antenna according to claim 1, characterized in that: The length of the X-direction patch antenna (3) in the X-axis direction is L x The length of the Y-direction patch antenna (4) in the Y-axis direction is L y , and L x ≠L y .

4. The building structure multi-directional tilt sensor based on dual patch antennas according to claim 1, characterized in that: The material of the overlying liquid container (7) is acrylic, and the overlying liquid container (7) is sealed as a whole, and the overlying liquid container (7) contains high dielectric constant liquid and air.

5. The building structure multi-directional tilt sensor based on dual patch antennas according to claim 3, characterized in that: When the overlying liquid container (7) is placed horizontally, the average height of the high dielectric constant liquid (8) inside the overlying liquid container (7) is h0; The length L of the side of the upper liquid container (7) in the X-axis direction ab Greater than the length L of the X-direction patch antenna (3) x ; and the length L of the side of the upper liquid container (7) in the Y-axis direction ad Greater than the length L of the Y-direction patch antenna (4) y .

6. The building structure multi-directional tilt sensor based on dual patch antennas according to claim 1, characterized in that: Components 1 and 2 of the building structure multi-directional tilt sensor are installed horizontally on the building structure as a whole, and when the building structure tilts, the building structure multi-directional tilt sensor tilts the same as the building structure, thereby changing the liquid level of the high dielectric constant liquid (8) in the overlying liquid container (7); The degree of inclination of the building structure in the X and Y directions is determined by determining the height of the liquid level of the high dielectric constant liquid (8) inside the overlying liquid container (7).

7. The building structure multi-directional tilt sensor based on dual patch antennas according to claim 6, characterized in that: The calculation method of the inclination of the building structure in the X and Y directions includes: S1: Assume that point a, point b, point c and point d are the contact points between the four corners of the overlying liquid container and the high-frequency dielectric plate, and point a is the intersection of the extension line of the outer edge of the patch antenna in the X direction and the extension line of the outer edge of the patch antenna in the Y direction, point b is on the extension line of the outer edge of the patch antenna in the X direction, and point d is on the extension line of the outer edge of the patch antenna in the Y direction; S2: The liquid level h after the building structure is tilted is inferred by the change of the resonant frequency of the patch antenna in the X direction and the patch antenna in the Y direction a ,h b and h d ; h a represents the height of the liquid level above point a, h b represents the liquid level above point b, h d Indicates the liquid level above point d; S3: The inclination of the building structure in the X-axis and Y-axis directions meets the following requirements: Among them, α x Indicates the inclination of the building structure in the X-axis direction; α y Indicates the inclination of the building structure in the Y-axis direction; L ab is the length of the side of the overlying liquid container in the X-axis direction, L ad is the length of the side of the overlying liquid container in the Y-axis direction; S4: After synthesizing the inclination vectors of the building structure in the X-axis and Y-axis directions, 360° inclination direction and inclination degree sensing in the plane is achieved.

8. The building structure multi-directional tilt sensor based on dual patch antennas according to claim 7, characterized in that: Step S2, inversely inferring the liquid level h after the building structure is tilted by the change of the resonant frequency of the patch antenna in the X direction and the patch antenna in the Y direction a ,h b and h d , specifically including: S21: According to the relevant electromagnetic theory, the calculation formula of the resonant frequency of the X-direction patch antenna and the Y-direction patch antenna is expressed as: Among them, f x is the resonant frequency of the patch antenna in the X direction, f y is the resonant frequency of the patch antenna in the Y direction; c is the propagation speed of electromagnetic waves in a vacuum, ε x is the effective dielectric constant of the high-frequency dielectric plate within the range of the patch antenna in the X direction; ε y is the effective dielectric constant of the high-frequency dielectric plate within the Y-direction patch antenna range, ε x and ε y Both are affected by the height of the high dielectric constant liquid in the liquid container above the patch antenna; L x is the length of the X-direction patch antenna in the X-axis direction, L y is the length of the Y-direction patch antenna in the Y-axis direction; Among them, ε x and ε y It is expressed as: Where ε0 is the initial dielectric constant of the high-frequency dielectric plate; k is the correlation coefficient between the effective dielectric constant and the height of the high dielectric constant liquid in the liquid container above the patch antenna; in, h b + h d =2*h0 (7) Then formula (6) can be rewritten as: Combining equations (3)(4)(5)(8), we can calculate h a and h b ; Then, h is calculated by formula (7): d .

9. A building structure multi-directional tilt monitoring system based on dual patch antennas, characterized in that: It comprises the building structure multi-directional tilt sensor and reader (9) as described in any one of claims 1 to 8; The building structure multi-directional tilt sensor is installed on the top of the building structure, and the reader (9) is placed in the vicinity of the building to be tested; The reader (9) transmits a frequency sweeping electromagnetic wave to the radio frequency chip (6) in the building structure multi-directional tilt sensor to activate the radio frequency chip (6); After the radio frequency chip (6) is activated, it generates current and transmits electromagnetic wave signals through the patch antenna. After the electromagnetic wave signals are received by the reader (9), data processing is performed to obtain the tilt direction and tilt degree of the building structure.

10. The building structure multi-directional tilt monitoring system based on dual patch antennas according to claim 9, characterized in that: The reader (9) comprises a wireless transceiver module, a control module, a modulation and demodulation module, and a digital processing module; The wireless transceiver module includes a transmitting and receiving antenna, which is used to transmit and receive modulated electromagnetic wave signals of different frequencies to the radio frequency chip in the building structure multi-directional tilt sensor; The modulation and demodulation module is used to modulate and demodulate the electromagnetic wave signals transmitted and received by the wireless transceiver module, and transmit the data information contained in the electromagnetic wave signals to the control module and the digital processing module; the data information includes the tilt sensor number and the measuring point position; The control module is used to control the reader to transmit modulated electromagnetic wave signals of different frequencies to the tilt sensor, and detect the threshold activation power of the radio frequency chip in the building structure multi-directional tilt sensor under the action of electromagnetic waves of different frequencies, thereby obtaining the resonant frequency information of the patch antennas in different directions in the sensor; The digital processing module calculates the inclination of the building structure in the X and Y directions according to the change in the resonant frequency of the patch antennas in two different directions of the sensor, and realizes the inclination monitoring of the building structure where the sensor is installed after vector synthesis.

Images