CN111351518A - Intelligent sensing equipment and method for safety of highway bridge structure - Google Patents
Intelligent sensing equipment and method for safety of highway bridge structure Download PDFInfo
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Abstract
The invention discloses a safety intelligent sensing device for a highway bridge structure, which comprises: the liquid level monitoring device comprises two sensing components, a liquid level monitoring device and a control device, wherein the sensing components comprise a base, a liquid storage cylinder and a liquid level observation pipe; the ultrasonic sensor assembly comprises at least three ultrasonic probes, one ultrasonic sensor assembly is arranged in a liquid storage cylinder of one sensing assembly, one ultrasonic probe forms a detection point, and the detection point is positioned at the bottom of the liquid storage cylinder and emits ultrasonic waves from bottom to top; and the transmission component comprises an optical fiber and an optical fiber modem. The invention also discloses an intelligent sensing method for the safety of the highway bridge structure. The invention realizes the local calibration of the sensor, eliminates the system error and has higher precision and reliability.
Description
Technical Field
The invention relates to the technical field of bridge engineering. More particularly, the invention relates to an intelligent sensing device and method for highway bridge structure safety.
Background
A large number of sensors are distributed in a traditional bridge structure health monitoring system and used for sensing information such as cracks, deformation, environment temperature and humidity, structure temperature and humidity, vehicle load and the like of a bridge structure. The service life of a bridge structure is usually 50-100 years, the sensor is stressed on steel and can be influenced by factors such as environment, faults, unknown input, material degradation and the like in the long-term working process, the looseness of a steel structure causes inevitable system errors in collected monitoring data, the precision and the long-term reliability of data collection are seriously influenced, and the effective service life of the sensor is shortened.
The accuracy and reliability of sensor data are improved at home and abroad, and multi-sensor data fusion proofreading is widely adopted. The data fusion technology focuses on the proofreading among multiple sensors, can reduce accidental errors, but cannot calibrate and eliminate system errors and cannot reverse the precision loss caused by long-term system errors. In order to ensure that the sensor can accurately reflect the real state of the structure, the method has important significance for self-calibration of the sensor. Self-calibration is the use of internal and external sensors to infer a monitored target value when the calibration target and a specific calibration procedure are unknown. The purpose of using a self-calibration method is to eliminate the significant, redundant and in some cases impossible to calibrate automation applications to ensure long-term automation. Self-calibration is an indispensable important component of a structural health monitoring system, and an accurate, efficient and robust self-calibration method needs to be researched.
The deflection and the spatial inclination angle of the structure are important indexes of the rigidity characteristic of the bridge. The change characteristics of the deflection and the inclination angle reflect the health state of the structure, so the method is an important index for monitoring the bridge. Currently, a communicating pipe based on a vibrating wire or an optical fiber sensor is mainly adopted to monitor the deflection; a micro-electro-mechanical system (MEMS) is adopted to measure the inclination angle of the structure, and no sensor adopting an ultrasonic method to measure the inclination angle is available.
Disclosure of Invention
An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.
The invention also aims to provide intelligent sensing equipment and method for the safety of the highway bridge structure, which realize local calibration of the sensor, eliminate system errors and have higher precision and reliability.
To achieve these objects and other advantages in accordance with the purpose of the invention, there is provided a smart security sensing apparatus for a highway bridge structure, comprising:
the sensing assemblies comprise bases, liquid storage cylinders and liquid level observation pipes, liquid is contained in the liquid storage cylinders, the liquid storage cylinders are further provided with vent holes, the liquid storage cylinders and the liquid level observation pipes of the sensing assemblies are communicated, the liquid storage cylinders of the two sensing assemblies are communicated through liquid communication pipes, the two sensing assemblies are both mounted on a beam body of a bridge, the bases are mounted at the same initial height, one sensing assembly is located above a bridge pier, and the other sensing assembly is located in a span;
the ultrasonic sensor assembly comprises at least three ultrasonic probes, one ultrasonic sensor assembly is arranged in a liquid storage cylinder of one sensing assembly, one ultrasonic probe forms a detection point, and the detection point is positioned at the bottom of the liquid storage cylinder and emits ultrasonic waves from bottom to top;
and the transmission assembly comprises an optical fiber and an optical fiber modem, wherein the cable of the ultrasonic probe is connected with the optical fiber modem, and the vibration frequency received by the ultrasonic probe is subjected to sound-light-electricity conversion and then is transmitted to the cloud platform through the optical fiber.
Preferably, the ultrasonic sensor assembly includes three ultrasonic probes.
Preferably, the method further comprises the following steps:
the sensor group comprises an accelerometer, a speedometer, a deflectometer, a crack meter, a thermometer, a strain gauge and a pressure ring, and is arranged on a beam body, a stay cable, a suspender, a bridge tower and/or a bridge pier of the bridge.
The intelligent sensing method for the safety of the highway bridge structure comprises the following steps:
step 1) installing the intelligent express way bridge structure safety sensing equipment, wherein a sensing component positioned above a bridge pier is a datum point, and a sensing component positioned in a span is an observation point;
and 2) when the midspan is downwarped, sequentially emitting ultrasonic waves from the bottom surface to the reference point and the observation point by all ultrasonic probes in the liquid storage cylinder of the sensing assembly, reflecting the ultrasonic waves by the liquid level, simultaneously receiving the ultrasonic waves to form an ultrasonic matrix, solving a moment, obtaining the liquid level heights of the reference point and the observation point, and performing difference to obtain a difference value between the observation point and the reference point, namely the midspan deflection.
Preferably, the method further comprises the following steps:
and 3) obtaining the space coordinates of all detection points of the ultrasonic sensor assembly according to the liquid level height of the observation point, and calculating the space angle of the normal line of the water surface, namely the mid-span space inclination angle.
Preferably, the spatial angle of the water surface normal is calculated in step 3) by:
r＝r0+t(r1-r0)+s(r2-r0)，
wherein t and s are a pair of plane basis vectors, and satisfy- ∞ < t, s <infinity, r0、r1、r2Is the spatial coordinate r (x) of the detection point of three ultrasonic probesj,yj,zj) J is 0,1,2, r is the space coordinate of any point of the plane formed by the three detection points;
n(r-r0)＝0，n1(x-x0)+n2(y-y0)+n3(z-z0)＝0
wherein n is a normal vector;
and (3) solving a water surface normal equation according to the cross product of any two vectors of the water surface:
calculating the spatial angle of the water surface normal
I.e. the mid-span spatial tilt angle.
The invention at least comprises the following beneficial effects:
firstly, under the condition that a calibration target and a specific calibration program are unknown, a self-calibration method is adopted to infer a monitoring target value, and the automatic application that is obvious, redundant and incapable of being calibrated under certain conditions is eliminated, so that long-term automatic operation is ensured;
secondly, the static level is different from a conventional vibrating wire or optical fiber-based static level, a sensing element of the level is not in a stressed state, the problems of long-term creep, creep and failure do not exist, the precision and the stability of a sensor cannot be reduced after long-term use, ultrasonic waves transmitted and received in liquid are transmitted and received by an ultrasonic probe array, the resolution ratio can reach 0.005mm, the measurement precision is 0.01mm, and the requirement of high-precision level monitoring is met; wide voltage input DC is 10-36V, normal power consumption is 0.6W, and low power consumption meets the environmental requirement of long-term use of structural health monitoring; the electromagnetic and noise interference resistance is realized, and the influence of severe cold and freezing is avoided; the method can effectively reduce the relative error of the sensor data, basically realizes self calibration of the sensor, and effectively improves the measurement precision.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Drawings
FIG. 1 is a schematic structural view of one embodiment of the apparatus of the present invention;
FIG. 2 is a schematic view showing the internal construction of the apparatus shown in FIG. 1 according to the present invention;
figure 3 is a diagram of the field installation of the apparatus of the present invention.
Detailed Description
The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.
It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials, if not otherwise specified, are commercially available; in the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can, for example, be fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. The terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the invention and to simplify the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.
As shown in fig. 1-3, the present invention provides an intelligent sensing device for highway bridge structure safety, comprising:
two perception components, the perception component includes the base 6, the liquid storage cylinder 3, the liquid level observation tube 4, the base 6 is the installation position, can adopt the way of the pre-buried bolt, the bolt can choose M10-12mm, the liquid is contained in the liquid storage cylinder 3, the liquid is pure water of degasification, through the vacuum pump air exhaust or boil degasification cooling, can consider to mix antifreeze or copper sulfate or silicon oil, the liquid storage cylinder 3 also has the vent 2 to exhaust, the vent 2 is furnished with the plug through the trachea tee bend, with the atmosphere conduction, the liquid storage cylinder 3 of each perception component, the liquid level observation tube 4 communicate, the liquid storage cylinders 3 of two perception components communicate through the liquid pipe 5, through the liquid pipe 5 tee bend is furnished with the plug in order to avoid the night leakage, the air pressure above the inner page of the liquid storage cylinders 3 of two perception components and the internal pressure keep the unanimity, should be lower than both ends in the middle of, the liquid level observation pipe 4 is convenient for technicians to observe liquid level and ensures that liquid in the cylinder is sufficient, the two sensing assemblies are both arranged on a beam body of the bridge, the base 6 is arranged at the same initial height, the initial height is the same horizontal height in the initial stage of bridge construction, one sensing assembly is arranged above a pier, the pier can be considered as a fixed point which does not vertically displace relatively, so that the reference point is selected, the other sensing assembly is arranged in a midspan, and the sensing assembly is selected as an observation point due to the fact that the midspan can be warped downwards under the long-term use of the bridge;
the liquid storage device comprises two ultrasonic sensor assemblies, wherein each ultrasonic sensor assembly comprises at least three ultrasonic probes, three points form a plane, three detection points can measure data, the data measured by the detection points are more accurate, one ultrasonic sensor assembly is arranged in a liquid storage cylinder 3 of one sensing assembly, one ultrasonic probe forms one detection point, the detection point is positioned at the bottom of the liquid storage cylinder 3, and ultrasonic waves are emitted from bottom to top;
the transmission assembly comprises an optical fiber 1 and an optical fiber modem, wherein a cable of the ultrasonic probe can be welded and lengthened, is connected with a socket of the optical fiber modem, and transmits the vibration frequency received by the ultrasonic probe to the cloud platform through the optical fiber 1 after performing acousto-optic conversion.
In the technical scheme, different from the conventional static level based on vibrating wires or optical fibers, the sensing element of the level is not in a stressed state, the problems of long-term creep, creep and failure do not exist, the precision and the stability of the sensor cannot be reduced after long-term use, ultrasonic waves transmitted in liquid are transmitted and received by the ultrasonic probe array, the resolution ratio can reach 0.005mm, the measurement precision is 0.01mm, and the requirement of high-precision level monitoring is met; wide voltage input DC is 10-36V, normal power consumption is 0.6W, and low power consumption meets the environmental requirement of long-term use of structural health monitoring; the electromagnetic and noise interference resistance is realized, and the influence of severe cold and freezing is avoided; the invention can effectively reduce the relative error of the sensor data, basically realizes self calibration of the sensor and effectively improves the measurement precision.
In another aspect, the ultrasonic sensor assembly includes three ultrasonic probes. Three detection points can form a surface, an ultrasonic matrix can be obtained by adopting three ultrasonic probes, the measurement effect is good, and the cost is balanced.
In another technical solution, the method further comprises:
the sensor group comprises an accelerometer, a speedometer, a deflectometer, a crack meter, a thermometer, a strain gauge and a pressure ring, and is arranged on a beam body, a stay cable, a suspender, a bridge tower and/or a bridge pier of the bridge. The accelerometer, the speedometer, the deflectometer and the strain gauge are integrated stress, the crack gauge and the pressure ring are local stress, and the thermometer is environmental quantity, so that the bridge structure can be detected in multiple directions.
The intelligent sensing method for the safety of the highway bridge structure comprises the following steps:
step 1) installing the intelligent express way bridge structure safety sensing equipment, wherein a sensing assembly positioned above a bridge pier is a datum point, a sensing assembly positioned in a span is an observation point, the number of the observation points can be one or more, and the observation points are measured in parallel and are not influenced by each other;
step 2) when the liquid level in the liquid storage barrel 3 of the observation point rises during midspan downwarping, the downwarping value of the main beam during midspan can be obtained through water level measurement, for the reference point and the observation point, all ultrasonic probes in the liquid storage barrel 3 of the sensing assembly successively emit ultrasonic waves from the bottom surface upwards, the ultrasonic waves of each ultrasonic probe reach the water surface, and the ultrasonic waves are received simultaneously after being reflected by the liquid surface to form an ultrasonic matrix,
and (3) accurately obtaining the calibration value of the ultrasonic probe based on the parameter correction value according to the Jacobi matrix as long as the output/input characteristics of the ultrasonic probe system are kept unchanged during real-time calibration and measurement, the measurement precision of the ultrasonic probe system depends on the real-time calibration precision, no error is introduced due to instability caused by drift of any other time characteristics, the ultrasonic matrix is demodulated, analyzed and subjected to moment solving to obtain the reference point and the liquid level heights H2 and H1 of the observation point, and the difference delta is H1-H2 to obtain the difference value between the observation point and the reference point, namely the mid-span deflection.
In the technical scheme, the method can effectively reduce the relative error of the data of the ultrasonic probe, realizes self calibration based on the ultrasonic probe, and effectively improves the measurement precision.
In another technical solution, the method further comprises:
and 3) obtaining the space coordinates of all detection points of the ultrasonic sensor assembly according to the liquid level height of the observation point, and calculating the space angle of the normal line of the water surface.
In another technical solution, the way of calculating the spatial angle of the water surface normal in step 3) is:
r＝r0+t(r1-r0)+s(r2-r0)，
wherein t and s are a pair of plane basis vectors, and satisfy- ∞ < t, s <infinity, r0、r1、r2Is the spatial coordinate r (x) of the detection point of three ultrasonic probesj,yj,zj) J is 0,1,2, r is the space coordinate of any point of the plane formed by the three detection points;
n(r-r0)＝0，n1(x-x0)+n2(y-y0)+n3(z-z0)＝0
wherein n is a normal vector;
and (3) solving a water surface normal equation according to the cross product of any two vectors of the water surface:
calculating the spatial angle of the water surface normal
I.e. the mid-span spatial tilt angle.
And transmitting the demodulated data to a cloud platform in a communication optical fiber 1 or 4G wireless mode. The self-calibration of the structure is realized by the following three methods:
1) self-calibration of the same sensor at different times. The sensor is influenced by the inherent characteristics, data in the time span of one day, one month, one season, one year or even continuous years are regular, and the trend term of the data is worked out through least square fitting in time, so that the trend term is used as a self-calibration basis to judge and correct an abnormal point value or abnormal trend.
2) Redundant sensors in the same location or sensors in symmetrical locations are spatially self-calibrated. And the sensor data points and the trends at the same position or the symmetrical position are symmetrical, and the abnormal point values or the abnormal trends are judged and corrected.
3) The data items and the catastrophe points of different sensors on the same component present regularity, and the abnormal point value or abnormal trend is judged and corrected by using respective data curve slope items as trend items.
The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.
Claims (6)
1. Highway bridge structures safety wisdom perception equipment, its characterized in that includes:
the sensing assemblies comprise bases, liquid storage cylinders and liquid level observation pipes, liquid is contained in the liquid storage cylinders, the liquid storage cylinders are further provided with vent holes, the liquid storage cylinders and the liquid level observation pipes of the sensing assemblies are communicated, the liquid storage cylinders of the two sensing assemblies are communicated through liquid communication pipes, the two sensing assemblies are both mounted on a beam body of a bridge, the bases are mounted at the same initial height, one sensing assembly is located above a bridge pier, and the other sensing assembly is located in a span;
the ultrasonic sensor assembly comprises at least three ultrasonic probes, one ultrasonic sensor assembly is arranged in a liquid storage cylinder of one sensing assembly, one ultrasonic probe forms a detection point, and the detection point is positioned at the bottom of the liquid storage cylinder and emits ultrasonic waves from bottom to top;
and the transmission assembly comprises an optical fiber and an optical fiber modem, wherein the cable of the ultrasonic probe is connected with the optical fiber modem, and the vibration frequency received by the ultrasonic probe is subjected to sound-light-electricity conversion and then is transmitted to the cloud platform through the optical fiber.
2. The intelligent highway bridge structure safety perception device of claim 1, wherein the ultrasonic sensor assembly includes three ultrasonic probes.
3. The intelligent highway bridge structure safety perception device of claim 1, further comprising:
the sensor group comprises an accelerometer, a speedometer, a deflectometer, a crack meter, a thermometer, a strain gauge and a pressure ring, and is arranged on a beam body, a stay cable, a suspender, a bridge tower and/or a bridge pier of the bridge.
4. The intelligent sensing method for the safety of the highway bridge structure is characterized by comprising the following steps:
step 1) installing the intelligent express way bridge structure safety sensing equipment of any one of claims 1-2, wherein a sensing component positioned above a bridge pier is a datum point, and a sensing component positioned in a span is an observation point;
and 2) when the midspan is downwarped, sequentially emitting ultrasonic waves from the bottom surface to the reference point and the observation point by all ultrasonic probes in the liquid storage cylinder of the sensing assembly, reflecting the ultrasonic waves by the liquid level, simultaneously receiving the ultrasonic waves to form an ultrasonic matrix, solving a moment, obtaining the liquid level heights of the reference point and the observation point, and performing difference to obtain a difference value between the observation point and the reference point, namely the midspan deflection.
5. The intelligent perception method for highway bridge structure safety according to claim 4, further comprising:
and 3) obtaining the space coordinates of all detection points of the ultrasonic sensor assembly according to the liquid level height of the observation point, and calculating the space angle of the normal line of the water surface, namely the mid-span space inclination angle.
6. The intelligent perception method for highway bridge structure safety according to claim 5, wherein the spatial angle of the water surface normal is calculated in step 3) by:
r＝r0+t(r1-r0)+s(r2-r0)，
wherein t and s are a pair of plane basis vectors, and satisfy- ∞ < t, s <infinity, r0、r1、r2Is the spatial coordinate r (x) of the detection point of three ultrasonic probesj,yj,zj) J is 0,1,2, r is the space coordinate of any point of the plane formed by the three detection points;
n(r-r0)＝0，n1(x-x0)+n2(y-y0)+n3(z-z0)＝0
wherein n is a normal vector;
and (3) solving a water surface normal equation according to the cross product of any two vectors of the water surface:
calculating the spatial angle of the water surface normal
I.e. the mid-span spatial tilt angle.
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