Composite measurement method and device for measuring inclination angle and vibration speed of building structure

Abstract

The invention discloses a composite measurement method and device for measuring the inclination angle and the vibration speed of a building structure, and the method comprises the steps: receiving acceleration data collected by an MEMS acceleration sensor at high frequency and environment temperature data collected by a temperature sensor after the composite measurement device vibrates and is awakened; drawing a change curve of acceleration along with time according to the acceleration data; segmenting the change curve, carrying out integration on each segment of curve to obtain a plurality of segments of speed curves, and summarizing the plurality of segments of speed curves to obtain a complete speed curve; performing translation item removal processing on the complete speed curve, and outputting the maximum speed according to the processed speed curve; calculating the inclination angle of the building structure according to the acceleration data, and correcting the inclination angle by using the environment temperature data to obtain an actual inclination angle value; and outputting the maximum speed and the actual inclination angle value as measurement results. According to the invention, long-time automatic measurement of the inclination angle and the vibration speed of the building structure is realized, the inclination angle is corrected through the environment temperature, and the measurement precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building structure safety monitoring, and in particular to a composite measurement method and device for measuring the inclination angle and vibration speed of a building structure. Background Art

[0002] When evaluating the safety and reliability of building structures, vibration speed and inclination angle are two important indicators. If the vibration of a building exceeds the permissible threshold, a series of damages may occur. Long-term continuous vibration will also cause fatigue and overstress problems in the main load-bearing components, thereby endangering the safety of the building; and when the inclination angle of the building exceeds a certain limit, its structural stability will be threatened. Therefore, monitoring the inclination angle and vibration speed of the building structure is crucial for housing safety management.

[0003] However, the existing measuring devices have a single structure and function, and can only monitor one parameter, namely the inclination angle or the vibration speed. If you want to monitor these two indicators at the same time, you need to install and use two sensors, which not only increases the workload of the on-site installation personnel, but also greatly increases the cost of house safety monitoring. In addition, when measuring the inclination angle, the current inclinometer is easily affected by the on-site environment or human damage, which will affect the final measurement accuracy. Summary of the invention

[0004] In order to solve at least one of the above-mentioned technical problems, the present invention provides a composite measurement method and device for measuring the inclination angle and vibration velocity of a building structure.

[0005] In a first aspect, the present invention provides a composite measurement method for measuring the inclination angle and vibration velocity of a building structure, the method comprising:

[0006] When the composite measuring device is awakened by vibration, it receives the acceleration data collected by the MEMS acceleration sensor at high frequency and the ambient temperature data collected by the temperature sensor, and draws a curve of acceleration change over time based on the acceleration data;

[0007] The curve of acceleration changing with time is divided into segments, and multiple speed curves are obtained by integrating each segment, and the complete speed curve is obtained by summarizing. The complete speed curve is processed to remove the translation term, and the maximum speed is output according to the processed speed curve.

[0008] The inclination angle of the building structure is calculated based on the acceleration data, and the inclination angle is corrected using the ambient temperature data to obtain the actual inclination angle value;

[0009] The maximum speed and actual inclination angle are output together as measurement results.

[0010] Preferably, the method of correcting the inclination angle by using the ambient temperature data to obtain the actual inclination angle value includes:

[0011] Set multiple groups of temperature data and angle data, obtain the actual inclination values ​​at different temperatures and angles through temperature tests, and obtain data sets; the experimental angle range is [-10°, 10°], and the experimental temperature range is [-60℃, 60℃]; the angle interval during the experiment is 0.5°, and the temperature interval is 5℃;

[0012] The data set is input into the convolutional neural network optimization model trained based on the genetic algorithm. The angle interval and temperature interval are continuously refined through the convolutional neural network optimization model until the angle interval is 0.001° and the temperature interval is 0.1°C. The actual inclination values ​​corresponding to the refined different temperatures and angles are obtained to establish a mapping relationship table between different temperatures, angles and actual inclination values.

[0013] According to the measured inclination angle of the building structure and the ambient temperature, the actual inclination angle value of the building structure is matched in the mapping relationship table.

[0014] Preferably, the curve of acceleration changing with time is segmented, and each segment of the curve is integrated to obtain multiple segments of velocity curves, including:

[0015] Detrending the acceleration over time curve:

[0016] a i =A i -b1+b2iΔt;

[0017]

[0018] In the formula, A i is the original acceleration of the i-th sample collected, i=1,2,...N, N is the sample length; b1 and b2 are fitting coefficients, Δt is the sampling interval; k is the number of sampling points in the detrending term processing, satisfying k=1,2,...N, a i is the acceleration data after removing the trend term;

[0019] According to the acceleration data after detrending, a new acceleration-time curve is drawn and segmented. After integrating each segment, multiple velocity curves are obtained:

[0020]

[0021] Where V j represents the velocity curve obtained after integration, j represents the amount of data contained in the integral of a section of the curve, there are n of them, satisfying j=1,2,...n.

[0022] Preferably, the processing of removing translation items from the complete velocity curve comprises:

[0023] Perform the de-translation processing on each speed data in the complete speed curve:

[0024]

[0025] Where v represents the velocity data after removing the translation term, and V represents the velocity data before removing the translation term.

[0026] Preferably, after the acceleration-time variation curve is subjected to detrending term processing, the method further comprises:

[0027] Perform Fourier transform on the acceleration variation curve obtained after removing the trend term to obtain the spectrum curve;

[0028] Based on the frequency corresponding to the maximum amplitude output of the spectrum curve, the frequency change is determined according to the frequency corresponding to the maximum amplitude, and the damage of the building structure is evaluated according to the frequency change.

[0029] Preferably, after outputting the maximum speed and the actual inclination angle value as the measurement results, the method further comprises:

[0030] When it is monitored that the maximum speed exceeds a preset vibration speed threshold, or the actual inclination value of the building structure exceeds a preset inclination threshold, an alarm prompt is triggered.

[0031] In a second aspect, the present invention further provides a composite measuring device for measuring the inclination angle and vibration velocity of a building structure, which is used to implement the composite measuring method for measuring the inclination angle and vibration velocity of a building structure as described in any one of the first aspects, and the device comprises:

[0032] The chassis and the protective shell; the protective shell and the chassis are connected by snap-fit, and a waterproof ring is provided at the connection of the protective shell;

[0033] The protective shell is provided with a plurality of positioning and mounting grooves on its circumference and are evenly distributed;

[0034] The chassis is provided with a control mainboard, a battery and a sensor group;

[0035] The battery is used to power the composite measuring device;

[0036] The control mainboard is used to generate control instructions to control the sensor group to collect data, and the sensor group includes a MEMS acceleration sensor and a temperature sensor; the MEMS acceleration sensor is used to collect acceleration data of the building structure at high frequency, and the temperature sensor is used to collect ambient temperature data; wherein,

[0037] An edge algorithm is deployed in the MEMS acceleration sensor, and the edge algorithm is used to calculate the vibration speed of the building structure according to the acceleration data, and is also used to calculate the inclination angle of the building structure according to the acceleration data, and correct the inclination angle using the ambient temperature data.

[0038] Preferably, the device further comprises a vibration awakening unit, which is used to automatically awaken the composite measurement device when it is detected that the vibration acceleration of the building structure exceeds a preset threshold.

[0039] Preferably, the protective housing is embedded with indicator lights; the indicator lights include a status light, a flashing light and a charging light;

[0040] The status light is used to display different colors when the composite measuring device is in different working states;

[0041] The strobe light is used to give an alarm prompt by strobing;

[0042] The charging light is used to display the charging status.

[0043] Preferably, the chassis is also provided with an external interface, including a SIM card slot and a Type-C port; the external interface is used for connecting an external battery, a power bank or a solar panel

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1) The composite monitoring method provided by the present invention can simultaneously measure two parameters, namely, the inclination angle and the vibration velocity. Compared with the existing method of requiring different devices to measure the two parameters separately, the present invention can integrate the composite measurement function, is easy to use and reduces the measurement cost.

[0046] 2) When measuring vibration velocity, the present invention first removes the trend term of the acceleration change curve, divides the curve into multiple integrals, and reduces the integral error by as small a sampling interval as possible; finally, the obtained complete velocity curve is processed to remove the translation term to eliminate the integral error caused by the translation term, thereby greatly improving the measurement accuracy of the vibration velocity. By using the ambient temperature to correct the measured inclination angle, the deficiency of the existing inclinometer that the ambient temperature cannot be measured can be compensated, and the measurement accuracy of the inclination angle of the building structure can be improved.

[0047] 3) After detrending the acceleration change curve, the present invention obtains a spectrum curve through Fourier transform; based on the frequency corresponding to the maximum amplitude output of the spectrum curve, the frequency change is determined according to the frequency corresponding to the maximum amplitude, and the damage to the building structure is evaluated according to the frequency change, thereby enhancing the energy efficiency of building structure safety monitoring. In addition, in the measurement method of the present invention, when the monitoring data reaches the warning value, the strobe light will turn on the strobe mode for warning, thereby improving the safety monitoring performance.

[0048] 4) In view of the problem that current measuring devices are easily damaged by the on-site environment or human damage, have small battery capacity, and cannot last for a long time, resulting in interruption of monitoring data, the composite measuring device provided by the present invention uses a protective shell in an approximately arc shape to protect the internal device, and adopts a 20,000 mAh lithium battery to power the equipment, which can achieve long battery life and solve the problem of insufficient power supply capacity and short battery life of existing measuring devices.

[0049] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background technology, the drawings required for use in the embodiments of the present invention or the background technology will be described below.

[0051] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and are used to illustrate the technical solutions of the present disclosure together with the specification.

[0052] Figure 1 A top view of a protective housing of a composite measuring device for measuring the inclination angle and vibration velocity of a building structure provided by an embodiment of the present invention;

[0053] Figure 2 for Figure 1 A schematic diagram of the structure of the chassis corresponding to the protective housing;

[0054] Figure 3 is a side view of the composite measuring device;

[0055] Figure 4 It is a structural schematic diagram of a breathable mesh plate used in a chassis;

[0056] Figure 5 A schematic flow chart of a measurement method of a composite measurement device for measuring the inclination angle and vibration velocity of a building structure provided by an embodiment of the present invention;

[0057] Figure 6 A schematic diagram of a flow chart of measuring vibration velocity provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0060] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] At present, the vibration and tilt of building structures are often measured separately and cannot be integrated into the same device, which increases the monitoring cost. The following problems usually exist in the method of installing inclinometers on building structures to automatically monitor the tilt changes of structures: 1) The existing inclinometer positioning and installation holes are small. Once one hole is drilled off, all holes need to be drilled again; 2) The battery capacity is small and the endurance is poor. It is impossible to collect data for a long time at a high frequency, and it is easy to interrupt the monitoring data; 3) The complex on-site environment is easy to affect the inclinometer or even damage it, resulting in inaccurate monitoring data; 4) The existing inclinometer cannot measure the ambient temperature and cannot eliminate the influence of the ambient temperature on the measurement data.

[0062] To this end, the present invention aims to provide a composite measuring device and method, which can use one device to simultaneously measure the inclination angle and vibration speed of a building structure. The device includes a protective shell, which can protect the internal device, reduce the impact of the on-site environment on it, and increase the service life of the built-in sensor; the protective shell is arc-shaped, and the positioning installation hole is changed to an installation positioning groove for easy positioning and installation; it contains a 20,000 mAh rechargeable lithium battery and a temperature sensor inside, which can measure the ambient temperature to facilitate the correction of the measured inclination angle, thereby obtaining the actual inclination angle value, while reducing the measurement cost and improving the measurement accuracy and operating convenience.

[0063] In one embodiment, the present invention provides a composite measuring device for measuring the inclination angle and vibration velocity of a building structure. Figure 1-2 , Figure 1 Schematic diagram of the structure of the protective housing of the composite measuring device, Figure 2 The schematic diagram of the structure of the chassis of the composite measuring device is shown in FIG. Specifically, the device includes:

[0064] Chassis and protective shell; the protective shell and the chassis are connected by snap-fit, and a waterproof ring 2 is provided at the connection of the protective shell; a plurality of positioning and mounting grooves 1 are provided on the circumference of the protective shell, and are evenly distributed;

[0065] The chassis contains the control motherboard, battery and sensor group;

[0066] The battery is used to power the composite measuring device;

[0067] The control mainboard is used to generate control instructions to control the sensor group to collect data. The sensor group includes a MEMS acceleration sensor and a temperature sensor. The MEMS acceleration sensor is used to collect acceleration data of the building structure at high frequency, and the temperature sensor is used to collect ambient temperature data. Among them,

[0068] An edge algorithm is deployed in the MEMS acceleration sensor, which is used to calculate the vibration speed of the building structure based on the acceleration data, and is also used to calculate the inclination angle of the building structure based on the acceleration data, and correct the inclination angle using the ambient temperature data.

[0069] In this embodiment, the protective shell is approximately arc-shaped and mainly plays a protective role, protecting the various devices inside the chassis, that is, the control motherboard and the sensor from being damaged by the on-site environment or human damage. Among them, a number of positioning and installation grooves 1 are arranged on the circumference of the protective shell and are evenly distributed. During the design process, three positioning and installation grooves 1 can be reserved for installation on the building structure, such as Figure 1 shown.

[0070] Preferably, the protective housing is connected to the chassis by snap-fit ​​connection, that is, Figure 1The buckle 3 in the bottom plate is connected with the corresponding hole buckle of the bottom plate. In addition, the protective shell and the bottom plate can also be connected by threaded connection to assemble the protective shell and the bottom plate.

[0071] Furthermore, there are waterproof rings 2 at the connection points of the protective shell to prevent rainwater from entering the interior and causing damage to the main control board, sensors, etc. It is made of thermoplastic polymer material, which is light, strong and high temperature resistant. Internal devices, such as sensors, are protected by the shell and can be recycled repeatedly, saving monitoring costs.

[0072] Preferably, the control mainboard and the sensor group together constitute a control unit 5 for collecting data and measuring and analyzing. The battery is placed in the battery compartment 6 to power the device.

[0073] Preferably, an indicator light 4 is embedded on the protective housing; the indicator light 4 includes a status light, a flashing light and a charging light;

[0074] The status light is used to display different colors when the composite measuring device is in different working states;

[0075] The strobe light is used to give an alarm prompt through flashing;

[0076] The charging light is used to show the charging status.

[0077] In this embodiment, three indicator lights 4 are embedded on the protective shell, namely, the status light, the flashing light and the charging light. The status light mainly reflects the working status of the device. When the device is turned on or wakes up regularly to collect data, the status light is always red. When the device is dormant, the status light is off. When the mobile terminal is connected to the device via Bluetooth for debugging, the status light is always purple. The flashing light mainly uses electronic components to flash the light source slowly or quickly, which plays the role of on-site reminder and warning. When the monitoring data collected by the device exceeds the set monitoring alarm threshold, the flashing light turns on the strobe mode to remind the on-site personnel to pay attention or stay away. When the alarm situation is eliminated, the platform sends the alarm elimination command to the device, and the flashing light goes out. The charging light will be always on when it is charging, and it will go out when the charging is completed. In addition, the installation mark is printed on the protective shell.

[0078] See also Figure 3 , Figure 3 is a side view of the device. Figure 2-3 It can be seen that the chassis is also provided with an external interface 7, including a SIM card slot and a Type-C port for external batteries, power banks or solar panels.

[0079] The external interface 7 mainly includes a SIM card slot and a Type-C port, which can be directly connected to an external battery, a power bank or a solar panel to meet emergency, short-term and long-term monitoring and endurance requirements. When installed, the external interface 7 faces downward to prevent rainwater from entering on rainy days.

[0080] See also Figure 4 , Figure 4 This is a bottom view of the device, looking up from the bottom of the chassis. The chassis adopts a breathable mesh plate 8 structure, which can enhance the heat dissipation effect when the device is running, and has the advantages of reducing dust accumulation, reducing the weight of the device and facilitating carrying.

[0081] Preferably, the battery is a 20,000 mAh lithium battery. By using a 20,000 mAh lithium-ion battery to power the device, a long battery life can be achieved, solving the problem of insufficient power supply capacity and short battery life.

[0082] Preferably, the composite measuring device further comprises a vibration awakening unit, which is used to automatically awaken the composite measuring device when it is detected that the vibration acceleration of the building structure exceeds a preset threshold.

[0083] In addition to conventional timed monitoring, because in most cases, MEMS accelerometers are in a dormant state, conventional MEMS accelerometers are prone to miss dangerous and abnormal conditions of the house. In this embodiment, there is a vibration wake-up device inside the device. When the vibration of the building exceeds the threshold (the threshold can be automatically set and adjusted), the device will be automatically awakened, and the collected data will be sent back to the monitoring platform. At the same time, in order to monitor and analyze the vibration of the building, the collection strategy of this scheme is quite different from that of the conventional inclinometer. In order to further analyze the acceleration measured by the sensor, after the device wakes up, data above 100Hz will be collected within 5s. The vibration analysis process is placed in the edge computing, and data processing, storage and analysis are performed where the data is generated, which reduces the need to transmit data to the cloud for processing, and can solve the transmission problem of a large amount of vibration data. After the vibration data processing and analysis are completed, the maximum value of the absolute value of the frequency and velocity signal and other data are transmitted back to the platform together with the inclination and temperature data.

[0084] In one embodiment, specific parameters of the composite measuring device are given, as shown in Table 1.

[0085] Table 1 Equipment parameter description

[0086]

[0087]

[0088] Therefore, the composite measuring device provided by the present invention utilizes an arc-shaped protective shell to protect the internal device. At the same time, when the monitoring data reaches the warning value, the strobe light will turn on the strobe mode for warning. In addition to the MEMS acceleration sensor, the device also contains a temperature sensor, which can measure the two parameters of inclination and vibration speed at the same time. Compared with the existing method of requiring different equipment to measure these two parameters separately, the present invention can integrate composite measurement functions, is easy to use and reduces the cost of the device. In addition, since a temperature sensor is provided, it can make up for the deficiency of the existing inclinometer that cannot measure the ambient temperature. The device not only protects the internal device to the greatest extent, realizes long-term automatic monitoring of inclination and vibration, but also can measure the surrounding environmental temperature, so as to eliminate the influence of ambient temperature on the measurement data, greatly improving the measurement accuracy.

[0089] See also Figure 5-6 , Figure 5 A flow chart of the retest measurement method is provided. Figure 6 Schematic diagram of the process for measuring vibration velocity.

[0090] like Figure 5 As shown, in one embodiment, the present invention further provides a composite measurement method for measuring the inclination angle and vibration velocity of a building structure, which is applied to the composite measurement device for measuring the inclination angle and vibration velocity of a building structure provided in the above embodiment, and the method includes:

[0091] S10, when the composite measuring device is awakened by vibration, it receives the acceleration data collected by the MEMS acceleration sensor at high frequency and the ambient temperature data collected by the temperature sensor, and draws a curve of acceleration change over time according to the acceleration data;

[0092] S20, segmenting the curve of acceleration changing with time, integrating each segment of the curve to obtain multiple segments of velocity curves, and summarizing to obtain a complete velocity curve; performing translation item removal processing on the complete velocity curve, and outputting the maximum velocity according to the processed velocity curve;

[0093] S30, calculating the inclination angle of the building structure according to the acceleration data, and correcting the inclination angle using the ambient temperature data to obtain an actual inclination angle value;

[0094] S40: Output the maximum speed and the actual inclination angle as measurement results.

[0095] In this embodiment, the composite measuring device automatically wakes up when it detects vibration. Acceleration data from the MEMS acceleration sensor and ambient temperature data from the temperature sensor are collected at high frequency. The change of acceleration over time is visualized by drawing an acceleration-time curve. When calculating the vibration velocity, the acceleration-time curve is processed in sections, and each section is integrated to convert it into a velocity curve. These velocity curves are merged to form a complete velocity curve. The translation term is removed from the complete velocity curve, that is, the fixed offset caused by non-vibration is eliminated, and the maximum velocity value is determined based on the processed curve. When calculating the inclination angle, the acceleration data is used to calculate the inclination angle of the building during vibration. The inclination angle measurement value is adjusted using the ambient temperature data to compensate for the impact of temperature changes on the sensor readings, so as to obtain a more accurate actual inclination angle, and finally the measurement results including the maximum velocity and the actual inclination angle corrected by temperature are output.

[0096] Therefore, this embodiment uses a composite measurement method, high-frequency sampling and temperature compensation technology to improve the measurement accuracy of vibration velocity and inclination, making the analysis result more reliable and improving the safety monitoring performance of the building structure.

[0097] In one embodiment, in step S20, the curve of acceleration changing with time is segmented, and each segment of the curve is integrated to obtain multiple segments of velocity curves, including:

[0098] Detrending the acceleration over time curve:

[0099] a i =A i -b1+b2iΔt;

[0100]

[0101] In the formula, A i is the original acceleration of the i-th sample collected, i=1,2,...N, N is the sample length; b1 and b2 are fitting coefficients, Δt is the sampling interval; k is the number of sampling points in the detrending term processing, satisfying k=1,2,...N, a i is the acceleration data after removing the trend term;

[0102] According to the acceleration data after detrending, a new acceleration-time curve is drawn and segmented. After integrating each segment, multiple velocity curves are obtained:

[0103]

[0104] Where V j represents the velocity curve obtained after integration, j represents the amount of data contained in the integral of a section of the curve, there are n of them, satisfying j=1,2,...n.

[0105] In order to improve the accuracy of the velocity curve obtained by integrating the acceleration data, it is first necessary to perform detrending on the original acceleration curve over time. This is because in the actual measurement process, due to the influence of sensor drift, environmental factors or installation position, the collected acceleration data may contain long-term trend offsets, that is, fixed offsets not caused by vibration. If these offsets are not processed, they will accumulate into significant errors during the integration process, affecting the accuracy of the final velocity calculation.

[0106] After detrending, a new acceleration-time curve is obtained. In order to minimize the integration error, the 100 vibration data can be divided into one segment, or even more finely divided, and then each segment is integrated to make the result of the integration as close to the true value as possible. j In the calculation formula, in order to minimize the integral error, Δt should be minimized. Since the sampling frequency is usually 50 Hz or 100 Hz, the value of the sampling interval Δt should be less than or equal to 0.02s. The smaller the sampling interval, the higher the calculation accuracy. In the actual process, the specific sampling frequency should be considered comprehensively considering the two factors of measurement cost and measurement accuracy. No further limitation is made here.

[0107] Since the integration process is affected by the "translation term", in one embodiment, after obtaining the complete speed curve, it is necessary to remove the translation term from the complete speed curve, and output the maximum speed according to the processed speed curve; wherein the translation term processing process is as follows:

[0108] Perform the de-translation processing on each speed data in the complete speed curve:

[0109]

[0110] Where v represents the velocity data after removing the translation term, and V represents the velocity data before removing the translation term.

[0111] Therefore, this embodiment can effectively eliminate the fixed offset caused by the sensor installation position or initial conditions by removing the translation term, so that the velocity data more accurately reflects the actual motion state of the object without including these irrelevant offset information. Without the translation term removal processing, any fixed offset will gradually accumulate during the integration process, resulting in a large error. By removing the translation term, this error accumulation can be significantly reduced, which can greatly improve the measurement accuracy during long-term monitoring of building structures.

[0112] In one embodiment, the principle of calculating the inclination angle of the building structure based on acceleration data is Newton's second law. Under external action, the object to be measured (mass m) is acted upon by the inertial force F and the spring force, resulting in a displacement x. When the spring force is balanced with the inertial force generated by the accelerated motion of the object to be measured, there will be no relative motion between the object to be measured and the ground. At this time, the deformation of the spring (i.e., the displacement x of the object) reflects the magnitude of the measured acceleration a. According to Newton's second law, the relationship between the inertial force F and the measured acceleration a is shown in the following formula:

[0113] F = μx = -ma;

[0114]

[0115] Where: μ is the stiffness coefficient of the spring, x is the displacement of the object being measured, and m is the mass of the object being measured.

[0116] In actual measurement, after the MEMS acceleration sensor obtains a certain amount of acceleration data within a specified time, the mean and standard deviation of the acceleration are obtained. If the difference between all accelerations and the average acceleration is within 3 times the standard deviation, the structural inclination is calculated based on the mean acceleration. However, there is still a deviation between the inclination calculated in this way and the actual inclination value, because the inclination measurement will be affected by the ambient temperature. Therefore, in order to accurately measure the inclination, in one embodiment, it is also necessary to obtain the ambient temperature collected by the temperature sensor, and use the ambient temperature to correct the inclination to obtain the actual inclination value.

[0117] Specifically, the method of correcting the inclination angle by using the ambient temperature to obtain the actual inclination angle value includes:

[0118] Set multiple groups of temperature data and angle data, obtain the actual inclination values ​​at different temperatures and angles through temperature tests, and obtain data sets; the experimental angle range is [-10°, 10°], and the experimental temperature range is [-60℃, 60℃]; the angle interval during the experiment is 0.5°, and the temperature interval is 5℃;

[0119] The data set is input into the convolutional neural network optimization model trained based on the genetic algorithm. The angle interval and temperature interval are continuously refined through the convolutional neural network optimization model until the angle interval is 0.001° and the temperature interval is 0.1°C. The actual inclination values ​​corresponding to the refined different temperatures and angles are obtained to establish a mapping relationship table between different temperatures and angles and the actual inclination values.

[0120] According to the measured inclination angle of the building structure and the ambient temperature, the actual inclination angle value of the building structure is matched in the mapping relationship table.

[0121] This embodiment can more accurately reflect the real inclination of the building structure under different temperature conditions by establishing a mapping relationship table based on experimental data. This method takes into account the influence of temperature changes on the thermal expansion and contraction of materials, thereby improving the accuracy of inclination measurement. Since the experiment covers a wide range of temperature (-60°C to 60°C) and angle range (-10° to 10°), it can be applied to building structure monitoring under various environmental conditions. By optimizing the convolutional neural network model through genetic algorithm and gradually refining the angle interval (from 0.5° to 0.001°) and temperature interval (from 5°C to 0.1°C), more detailed data points can be obtained, so that the final mapping relationship table can provide a very accurate estimate of the actual inclination value. In the long-term monitoring process, changes in ambient temperature may cause cumulative errors in traditional measurement methods. This method effectively reduces the accumulation of such errors by updating the actual inclination value in real time or regularly, ensuring the consistency and reliability of the monitoring results. By accurately measuring the inclination value of the building structure, potential safety hazards can be discovered in time and corresponding measures can be taken to improve the safety of housing construction and use.

[0122] It should be noted that the entire algorithm process for calculating the vibration velocity and inclination angle is deployed in the front-end sensor, and the sensor only needs to send back the maximum and minimum values ​​in the final velocity curve v. It can be understood that v on the velocity curve has positive and negative values, and the maximum value (positive number) and the minimum value (negative number) are sent together, and the maximum velocity is taken as the final measured vibration velocity after taking the absolute value.

[0123] In one embodiment, after the acceleration-time variation curve is subjected to detrending term processing, the frequency is also monitored, such as Figure 6 The specific process is as follows:

[0124] Perform Fourier transform on the acceleration variation curve obtained after removing the trend term to obtain the spectrum curve;

[0125] Based on the frequency corresponding to the maximum amplitude output of the spectrum curve, the frequency change is determined according to the frequency corresponding to the maximum amplitude, and the damage of the building structure is evaluated according to the frequency change.

[0126] Specifically, the Fourier transform process is as follows:

[0127]

[0128] Where F(w) is the frequency domain curve, f(t) is the acceleration variation curve with time after removing the trend term, and w is the frequency.

[0129] In this embodiment, it is necessary to find the frequency point corresponding to the maximum amplitude on the obtained frequency spectrum curve, which usually represents the main vibration frequency or resonant frequency of the structure, and it reflects the most active response frequency of the building structure during vibration. Based on a long-term monitoring process, the frequency change within a certain time range can be obtained. It is understandable that each building structure has its own unique natural frequency (or resonant frequency), which is determined by the geometry of the structure, material properties (such as elastic modulus), boundary conditions and mass distribution. When the frequency of the external force applied to the structure is close to these natural frequencies, the structure will resonate and show a larger vibration amplitude. If the building structure is damaged, such as cracks, material aging or loose components, this will usually lead to a decrease in structural stiffness. And the change in stiffness will be directly reflected in the natural frequency of the structure. After converting the acceleration signal in the time domain into a frequency domain signal through Fourier transform, the various frequency components and their corresponding amplitudes can be clearly seen. For a building structure in good health, its spectrum should be relatively stable; once the structure is damaged, especially those factors that affect the stiffness and mass distribution, some frequency components in the spectrum will change significantly, and the most intuitive manifestation is that the frequency corresponding to the maximum amplitude has shifted, or the frequency fluctuates greatly. Therefore, by monitoring the frequency changes, the damage of the building structure can be estimated in advance, thereby improving the monitoring efficiency and providing timely warnings when abnormalities occur.

[0130] In one embodiment, after the maximum speed and the actual inclination angle value are outputted together as the measurement results, the method further comprises:

[0131] When it is monitored that the maximum speed exceeds a preset vibration speed threshold, or the actual inclination value of the building structure exceeds a preset inclination threshold, an alarm prompt is triggered.

[0132] Existing monitoring equipment does not have the function of timely on-site warning. Generally, the monitoring personnel will notice that the monitoring data of the monitoring cloud platform exceeds the limit, and immediately go to the site to check the situation, notify relevant personnel, and carry out warning processing. Real-time warning cannot be achieved. The protective shell of the device of the present invention is embedded with three indicator lights, namely the status light, the flashing light and the charging light. The status light mainly reflects the working status of the device. When the device is turned on or wakes up regularly to collect data, the status light is always red. When the device is dormant, the status light is off. When the mobile terminal is connected to the device via Bluetooth for debugging, the status light is always purple; the flashing light mainly uses electronic components to flash the light source slowly or quickly, which plays the role of on-site reminder and warning. When the monitoring data (vibration speed and inclination angle) collected by the device exceeds the set monitoring alarm threshold, the flashing light turns on the strobe mode to remind the on-site personnel to pay attention or stay away. When the alarm situation is eliminated, the platform sends an alarm cancellation command to the device, and the flashing light goes out; the charging light will be always on when it is charging, and it will go out when the charging is completed.

[0133] Therefore, the measurement method provided by the present invention uses a MEMS acceleration sensor to monitor the inclination of the house in real time; at the same time, a certain period of time is selected for high-frequency acquisition, the high-frequency acquired data is analyzed, and the vibration speed of the structure is calculated. The algorithm is placed at the front end, reducing the need to transmit data to the cloud for processing, and can solve the problem of transmitting a large amount of vibration data. After measuring the inclination angle, the inclination angle will be corrected in combination with the temperature data collected by the temperature sensor to obtain the actual inclination angle value, thereby greatly improving the measurement accuracy of the inclination angle. When the monitored inclination angle value or vibration speed exceeds the limit value, an early warning will be issued immediately. The device is easy to install and low in cost, and can promote the development of the housing safety monitoring industry.

[0134] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. Those skilled in the art can also clearly understand that the descriptions of the various embodiments of the present invention have different focuses. For the convenience and brevity of description, the same or similar parts may not be repeated in different embodiments. Therefore, for parts not described or not described in detail in a certain embodiment, refer to the records of other embodiments.

Claims

1. A composite measurement method for measuring the inclination angle and vibration velocity of a building structure, characterized in that: The method comprises: When the composite measuring device is awakened by vibration, it receives the acceleration data collected by the MEMS acceleration sensor at high frequency and the ambient temperature data collected by the temperature sensor, and draws a curve of acceleration change over time based on the acceleration data; The curve of acceleration changing with time is divided into segments, and multiple speed curves are obtained by integrating each segment, and the complete speed curve is obtained by summarizing. The complete speed curve is processed to remove the translation term, and the maximum speed is output according to the processed speed curve. The inclination angle of the building structure is calculated based on the acceleration data, and the inclination angle is corrected using the ambient temperature data to obtain the actual inclination angle value; The maximum speed and actual inclination angle are output together as measurement results.

2. The composite measurement method for measuring the inclination angle and vibration velocity of a building structure according to claim 1, characterized in that: The method of correcting the inclination angle by using the ambient temperature data to obtain the actual inclination angle value includes: Set multiple groups of temperature data and angle data, obtain the actual inclination values ​​at different temperatures and angles through temperature tests, and obtain data sets; the experimental angle range is [-10°, 10°], and the experimental temperature range is [-60℃, 60℃]; the angle interval during the experiment is 0.5°, and the temperature interval is 5℃; The data set is input into the convolutional neural network optimization model trained based on the genetic algorithm. The angle interval and temperature interval are continuously refined through the convolutional neural network optimization model until the angle interval is 0.001° and the temperature interval is 0.1°C. The actual inclination values ​​corresponding to the refined different temperatures and angles are obtained to establish a mapping relationship table between different temperatures, angles and actual inclination values. According to the measured inclination angle of the building structure and the ambient temperature, the actual inclination angle value of the building structure is matched in the mapping relationship table.

3. The composite measurement method for measuring the inclination angle and vibration velocity of a building structure according to claim 1, characterized in that: The acceleration-time variation curve is segmented, and each segment of the curve is integrated to obtain multiple segments of velocity curves, including: Detrending the acceleration over time curve: a i =A i -b1+b2iΔt; In the formula, A i is the original acceleration of the i-th sample collected, i=1,2,...N, N is the sample length; b1 and b2 are fitting coefficients, Δt is the sampling interval; k is the number of sampling points in the detrending term processing, satisfying k=1,2,...N, a i is the acceleration data after removing the trend term; According to the acceleration data after detrending, a new acceleration-time curve is drawn and segmented. After integrating each segment, multiple speed curves are obtained: Where V j represents the velocity curve obtained after integration, j represents the amount of data contained in the integral of a section of the curve, there are n of them, satisfying j=1,2,...n.

4. The composite measurement method for measuring the inclination angle and vibration velocity of a building structure according to claim 3, characterized in that: The processing of removing the translation term from the complete speed curve includes: Perform the de-translation processing on each speed data in the complete speed curve: Where v represents the velocity data after removing the translation term, and V represents the velocity data before removing the translation term.

5. The composite measurement method for measuring the inclination angle and vibration velocity of a building structure according to claim 3, characterized in that: After the detrending term processing is performed on the acceleration-time variation curve, the method further includes: Perform Fourier transform on the acceleration variation curve obtained after removing the trend term to obtain the spectrum curve; Based on the frequency corresponding to the maximum amplitude output of the spectrum curve, the frequency change is determined according to the frequency corresponding to the maximum amplitude, and the damage of the building structure is evaluated according to the frequency change.

6. The composite measurement method for measuring the inclination angle and vibration velocity of a building structure according to claim 1, characterized in that: After the maximum speed and the actual inclination angle value are outputted as the measurement results, the method further includes: When it is monitored that the maximum speed exceeds a preset vibration speed threshold, or the actual inclination value of the building structure exceeds a preset inclination threshold, an alarm prompt is triggered.

7. A composite measuring device for measuring the inclination angle and vibration velocity of a building structure, used to implement the composite measuring method for measuring the inclination angle and vibration velocity of a building structure as claimed in any one of claims 1 to 6, characterized in that: The device comprises: The chassis and the protective shell; the protective shell and the chassis are connected by snap-fit, and a waterproof ring is provided at the connection of the protective shell; The protective shell is provided with a plurality of positioning and mounting grooves on its circumference and are evenly distributed; The chassis is provided with a control mainboard, a battery and a sensor group; The battery is used to power the composite measuring device; The control mainboard is used to generate control instructions to control the sensor group to collect data, and the sensor group includes a MEMS acceleration sensor and a temperature sensor; the MEMS acceleration sensor is used to collect acceleration data of the building structure at high frequency, and the temperature sensor is used to collect ambient temperature data; wherein, An edge algorithm is deployed in the MEMS acceleration sensor, and the edge algorithm is used to calculate the vibration speed of the building structure according to the acceleration data, and is also used to calculate the inclination angle of the building structure according to the acceleration data, and correct the inclination angle using the ambient temperature data.

8. The composite measuring device for measuring the inclination angle and vibration velocity of a building structure according to claim 7, characterized in that: The device also includes a vibration awakening unit, which is used to automatically awaken the composite measuring device when it is detected that the vibration acceleration of the building structure exceeds a preset threshold.

9. The composite measuring device for measuring the inclination angle and vibration velocity of a building structure according to claim 7, characterized in that: The protective housing is embedded with indicator lights; the indicator lights include a status light, a flashing light, and a charging light; The status light is used to display different colors when the composite measuring device is in different working states; The strobe light is used to give an alarm prompt by strobing; The charging light is used to display the charging status.

10. The composite measuring device for measuring the inclination angle and vibration velocity of a building structure according to claim 7, characterized in that: The chassis is also provided with an external interface, including a SIM card slot and a Type-C port; the external interface is used for an external battery, a power bank or a solar panel.

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