This application claims the priority benefit of Taiwan application serial no. 102210815, filed on Jun. 10, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
Technical Field
The invention relates to an apparatus and system combined with a structural safety monitoring function and a lighting function.
Related Art
A bridge across a valley or serving as a viaduct is constantly influenced by stableness of a foundation, and after the bridge suffers from wind, sunshine, rain and other weather changes for a long period of time, and is even wrecked by earthquakes, typhoons, lightning and other harsh weather conditions plus frequent overload of vehicles driving thereon and a fatigue stress load of long time vibration, either the bridge is naturally aged due to disrepair or sometimes the bridge encounters an accident of sudden tilt or fracture. Especially, bridges, buildings and other structures located in an area with frequent economic activities are in need of long-term monitoring. Conditions of roads and bridges in remote area are hard to be monitored and managed by manpower. Therefore, it is necessary and important to seek an economic and efficient solution.
In view of bridge structural health monitoring (SHM), a conventional method is to develop a bridge safety monitoring system by using hydraulic pressure gauges, inclinometers and tension meters, and the various sensors are connected to a data server through optical fiber wiring for data interpretation, and related data is transmitted to a cloud end through a telecommunication network, by which a pier tunneling condition, a bridge tilt condition and a bridge gap condition are automatically monitored to ensure safety of the bridge. A main disadvantage thereof lies in an expensive setup cost, and serial connection between the sensing nodes requires optical fiber or electric wire, and if a certain node is damaged, direct replacement thereof is not easy. Moreover, a city power or a large battery is required to supply power thereto. Therefore, since the deployment of the sensing nodes is not easy, and multi-point deployment cannot be implemented, there are many blind spots and omissions on a monitoring network. In some foreign countries, although a wireless sensor network (WSN) especially a Zigbee is used to monitor the bridge, a function thereof is limited to transmission of sensing data of the sensor of each node, and a whole operation mechanism or an added value is not provided. Moreover, the sensing data can only be transmitted through the WSN, and if any node or a main node of the WSN is damaged, or functions of the system are incomplete, or the whole system is malfunction, in case of absence of auto repair or absence of an emergency replacement mechanism, difficulties in manual maintenance and reconfiguration are additional encountered. Moreover, the aforementioned apparatus and system cannot monitor and warn the overload vehicles in real-time.
The invention provides a safety monitoring apparatus and a system thereof for bridge, building or structure, and a theory thereof is based on an energy method—the theorem of Castiano, by which when a structure is subjected to various loads (for example, vehicles, pedestrian, machinery, self weight, strong winds, heavy rain, river flow impact, terrain latent change or earthquake, etc.), and the structure is still in an elastic safety range, i.e. a stress of the material of the structure does not exceed a yield-point thereof, and a whole displacement is a linear function of a whole load, and an overlapping principle is applicable. Therefore, regardless of whether a single device is used to test one point or multiple devices are used to test different positions, and regardless of whether it is the maximum amplitude position or resonant node, the above theoretical basis can all be used to regard current data as safety amplitude, vibration frequency, etc. When any point on the structure is damaged, especially when a pier cornerstone is scoured and an exposed length thereof is changed, the pier cornerstone is eroded under water flow, and the structure is locally fractured in internal thereof, etc., there are different degrees of changes in a cross-sectional area, an elastic coefficient, a shear elastic coefficient, a shaft moment of inertia, a polar moment of inertia, a volume elastic coefficient, or even a length, etc. on a stress bearing point, which may accordingly change an amplitude, a vibration frequency, etc. of the structure, or present a high frequency vibration, sudden change, etc. in real-time. Under a long-term tracking and recording practise, safety peak data of different structures and different measuring points are obtained to accordingly define a time-scale threshold and an instantaneous strength threshold for safety monitoring. When the monitored data exceeds the threshold, the apparatus or system may send a warning message, and usage of the structure can be prohibited to prevent accidents, or the structure can be strengthened to prolong a service life thereof, or the structure can be locally strengthened to decrease a maintenance cost of the structure.
An embodiment of the invention provides a safety monitoring apparatus for bridge, building or structure, and each monitoring apparatus is installed with a three-axis accelerometer, by which not only a long-term variation of an inclination of a foundation at the installation place is monitored, a transient monitoring is also implemented, and a sensing value of the three-axis accelerometer is regularly read for determination. The determination is performed according to an inbuilt formula and historical data to determine whether there is a safety issue, where the inbuilt formula or a look-up table can be obtained by simulating the whole bridge to evaluate a safety data range of each node that is influenced by wind, earthquake or large vehicles, etc.
An embodiment of the invention provides a safety monitoring apparatus for bridge, building or structure, and each monitoring apparatus uses a solar battery as a power supply, and a consecutive wireless communication mechanism is used to transmit monitoring data, so as to facilitate installing outdoors for a long-term usage. Since electricity arrangement and wire arrangement are not required, in collaboration with a data processing capability of the apparatus, in case of a natural disaster, even if power and communication are cut off, the real-time and continuous security monitoring mechanism still functions. Since it is unnecessary to replace a battery, maintenance cost and related expenses are accordingly decreased. Since electricity arrangement and wire arrangement are not required, when a location of a monitoring spot is improper, the location can be easily changed for amelioration, and only a mechanical fixing part is required to be disassembled, and after reallocation is completed, the apparatus is reset to continue monitoring. Similarly, equipment replacement due to malfunction is also easy.
An embodiment of the invention provides a safety monitoring apparatus for bridge, building or structure, where each safety monitoring apparatus includes a light-emitting diode (LED) lighting mechanism and has a decoration effect. The apparatus self determines and sets a control instruction for lighting LED lamp beads according to a lighting intensity and a charging power of the apparatus, or obtains the control instruction of the LED lamp beads from external through a wireless communication module, and presents a lighting effect of different frequencies, colors and brightness according to the control instruction. Under a coding operation of the whole system, complicated decoration lighting patterns varied along with time can be presented, and a combination of a huge amount of the lighting patterns can serve as a billboard. In this case, an added value of the apparatus is increased, and when the apparatus is damaged, as the added value of the apparatus is accordingly disappeared, a repair and maintenance mechanism is forced to quickly react, by which integrity of the safety monitoring function is compensated and assisted, so as to avoid natural waste of the apparatus.
An embodiment of the invention provides a safety monitoring apparatus and a system thereof for bridge, building or structure, where each safety monitoring apparatus has a wireless communication function, and the apparatus can automatically switch a master-slave identity, and transmit data in a consecutive manner having a range exceeding a transmitting and receiving range of a single radio device, and can also directly communicate with a mobile communication device (a mobile phone or a tablet PC, etc.) in case that a radio communication gateway/router is damaged, and any ambient available mobile communication device serves as the gateway/router, and based on an automatic repair function, data is still transmitted to a main control center through Internet. When the communication is interrupted, the apparatus is capable of self processing data of detection sensor. Therefore, although the network is disconnected, and there is no available temporary gateway/router, the monitoring apparatuses can still communicate with each other, and when any single monitoring apparatus has a safety issue, a warning message is sent onsite, or neighbouring monitoring apparatuses are notified to commonly send the warning message, so as to achieve a maximum warning effect. Alternatively, the main control center is notified to decrease occurrence of structure accident, or the single apparatus send the warning message by itself to achieve a basic warning effect.
An embodiment of the invention provides a safety monitoring apparatus and a system thereof for bridge, building or structure, where each monitoring apparatus has a safety monitoring sensor and has a wireless communication function, and the apparatus can automatically switch a master-slave identity, and transmit data in a consecutive manner having a range exceeding a transmitting and receiving range of a single radio device, by regularly adjusting a timer of each monitoring apparatus, the monitoring apparatuses are synchronous, and then each of the monitoring apparatuses continuously records sensing values of the safety monitoring sensors thereof at a fixed sampling time, and transmits the sensing data to the main control center in batches for long-term recording or study and determination. A method of study and determination is to compare a normal value obtained through computer simulation according to dynamic behaviours of the monitored structure with a measuring value of each monitoring apparatus to determine whether the measuring value is abnormal.
An embodiment of the invention provides a safety monitoring on-site warning apparatus and a system thereof for bridge, building or structure. When a vehicle passing through the structure is overload, for example, a gravel truck, a heavy-duty vehicle, etc., based on monitoring of each location, as the vehicle produces a strong vibration that exceeds a safety threshold when passing through the structure, each of the monitoring apparatuses along the road displays an overload message through built-in LED lamps, so as to implement immediate interception to prevent continuous expansion of the destruction, or achieve a deterrent effect. In a storm, along with wind and rain of that moment and rising of water flow, it is determined whether a dangerous situation is entered in real-time, and the dangerous situation is indicated by a LED lamp message of the apparatus in real-time.
In summary, the invention provides a multi-function wireless safety monitoring apparatus and a system for bridge or building, which additionally have functions of illumination, decoration, display, warning, etc. to mitigate disadvantages of a conventional monitoring system, so as to create a globally applicable safety monitoring mechanism for bridge, building or structure, which not only has features of easy installation and easy setting, but also has a real-time monitoring function and a warning function, and is capable of safely operating when communication and power supply are cut off due to a natural disaster. Moreover, basic elements are creatively used to enhance an added value of the system, such that the safety monitoring system is more valuable, so as to avoid a situation of just finding that the monitoring apparatus set up according to the conventional technique has failed for a long time due to damage after occurrence of an accident, and losing the function of sending the warning message in time or in advance due to that the maintenance is not easy, or the communication and power supply are cut off in the surrounding area.
In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Hardware components of a structural safety monitoring and luminary lighting apparatus and a system thereof of the invention include a solar LED lamp wireless sensor device, a solar LED lamp wireless sensor device and a router of an inbuilt router, or in collaboration of a general router in the market, the apparatus and system can be connected to a server of the Internet and a main control center to form an integral monitoring and lighting system.
Basic Structure of the Solar LED Lamp Wireless Sensor Device
Referring to
Referring to
Referring to the circuit structure of
The safety sensor 19 of
Regarding the concept of three axial directions, regardless an angle change of the apparatus, the apparatus can simultaneously measure up and down or back and forth vibration values and resonant values of the bridge impacted by a horizontally flowed water flow and influenced by driving variations of vehicles passing there through. Therefore, based on the concept of the three axial directions, the apparatus is not influenced by a usage environment, an installation orientation, an angle status, etc., so as to avoid causing inconvenience in installation and application.
When the safety sensor 19 is a three-axis accelerometer and includes a temperature sensor, besides data of accelerations of each axial direction is measured, influence on variations of the structure due to temperature difference between day and night, and a temperature difference between four seasons is also measured.
When the safety sensor 19 is a three-axis accelerometer and includes an exposed humidity sensor, besides data of accelerations of each axial direction is measured, humidity of different parts of the structure or distribution of rain covering part of the structure can also be measured, so as to define different time-dimension thresholds to structure materials, or monitoring control values limited by a local maintenance period.
When the safety sensor 19 is a three-axis accelerometer and includes an exposed wind speed sensor, besides data of accelerations of each axial direction is measured, a relationship between the strong wind and a vibration response of the structure can also be measured.
When the safety sensor 19 is a three-axis accelerometer and includes an exposed water (liquid) level ultrasonic sensor, besides data of accelerations of each axial direction is measured, the safety sensor 19 can directly measure whether a water (liquid) level under the bridge exceeds a security alert level.
When the safety sensor 19 is a three-axis accelerometer and includes a tilt sensor, besides data of accelerations of each axial direction is measured, the safety sensor 19 can also be applied for monitoring railroad, electric tower, etc. deployed in wild to prevent subsidence, tilt and sliding of a foundation and tracks of the railroad.
Referring to
Embodiments of Communication Steps
As shown in
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As shown in
In an exemplary embodiment, the damage level of the bridge (i.e. structure) can be seen as the reduction of the natural (main) frequency of the structure, namely, the reduction of the stiffness. Based on ω=(k/m)1/2, where ω represents the natural frequency, k represents the stiffness, and m represents the mass. The variation of the mass is limited when the structure is fractured or the bridge pier is scoured and exposed, but the equivalent stiffness has a larger variation, and therefore, the reduction of the natural frequency is the reduction of the stiffness. If it wants to obtain the mode shape, the accelerometers respectively disposed on a plane between two adjacent bridge piers and installed in the solar LED lamp wireless sensor devices should simultaneously record and transmit the same to the central control unit for computing. In some exemplary embodiments, only a part of the solar LED lamp wireless sensor devices applied in the bridge monitoring may either be the three-axis accelerometers having high sensitivity and low noise or be the single-axis accelerometers (i.e. measuring the environment vibration of the portion(s) perpendicular to the bridge deck), and the other of the solar LED lamp wireless sensor devices applied in the bridge monitoring may be configured to serve as hops. For example, the corresponding references (i.e. natural frequency, damping ratio, etc.) can be assigned to each of the solar LED lamp wireless sensor devices for comparison, and then the parameters of the structure characteristics for each solar LED lamp wireless sensor device can be continuously sampled for every each time, wherein the sampling frequency can be between 100-2000 Hz, the resolution of the accelerometers is 16-bit or the above, and the noise of the accelerometers is 0.1-150 μg/Hz1/2, but not limited thereto.
In an exemplary embodiment, a pre-treatment can be performed on the signal(s) by an Ensemble Empirical Mode Decomposition (EEMD) method for eliminating the noise influence, and each mode can be determined by using Hilbert-Huang transform method. In addition, Random Decrement Technique (RDT) can be used to obtain the free vibration modal response for structure, and Ibrahim Time Domain (ITD) method can be used for identification. In the other exemplary embodiment, for the normal monitoring, Stochastic Subspace Identification-covariance driven (SSI-COV) and Recursive Stochastic Subspace Identification-covariance driven (RSSI-DATA & RSSI-COV) can also be used for identification. And, the dynamic parameters (for example, the natural frequency, damping, vibration mode, etc.) of the structure can be extracted according to the output information obtained by measuring the small vibration. At the abnormal state, the damage can be estimated by the measured signal(s), and different damage levels can be established for defining or obtaining the time, location, degree about damage happening.
Embodiments of Operation Steps of the Structural Safety Monitoring and Lighting System
Referring to
Referring to
Referring to
Referring to
Referring to
Embodiment for Monitoring a Bridge Structure
Referring to 8 steps shown in
Step one, solar LED lamp wireless sensor slave node(s): as shown in
Step two, solar LED lamp wireless sensor master node(s): as shown in
Step three, as shown in
Step four, as shown in
Step five, as shown in
Step six, as shown in
Step seven, as shown in
If more than one solar LED lamp wireless sensor devices discover abnormal conditions, the safety monitoring slave nodes can be directly changed to master nodes in succession, and scan the other neighbouring nodes, and the slave nodes written with data send messages including its own information and the abnormal sensing data in succession. Once the master node writes data into the selected slave node, the master node itself is immediately changed to a slave node, and stays to serve as the slave node by, for example, 60 seconds, so as to obtain a larger data transmission amount without occupying much permission of the master node. In this way, the worst case is that each node on the bridge has data to transmit, and it is assumed that a data transmission distance of each node is 50 meters, and a distance between two neighbouring nodes is 1 meter, so that the first to the fiftieth slave nodes that are closest to the relay station can all successfully transmit data to the relay station. Obviously, the farther a data transmission distance of each node is, the shorter time is required for transmitting the abnormal sensing data to the relay station, and the more denser the nodes is, the more possible a local damage situation is detected. In the present embodiment, each safety monitoring device is spaced from the neighbouring safety monitoring device by one meter, and when a safety issue occurs, a controller can easily focus on the problem, and deals with the problem in the most expeditious manner, so as to avoid occurrence of the safety problem.
Embodiment of Auto Repair of the Safety Monitoring System
If a relay station is damaged, the data can be transmitted to the undamaged relay station to automatically repair the communication system, so as to greatly improve reliability of the system.
In a method for determining whether the relay station is damaged, if the last node cannot transmit data to the relay station and the transmission cannot be implemented after three continuous attempts, it is determined that the relay station is malfunctioned. In the last, after the message is transmitted to another relay station without malfunction, the message can be transmitted to the main control center to implement maintenance and repair.
According to the data transmission method of the invention, a situation that the damaged slave node can still transmit data to the relay station is avoided, since when the abnormal node scans the valid slave nodes, according to the aforementioned embodiment, it is known that there are probably 50 slave nodes available for selection, so that the data can be indeed transmitted to the relay station. Moreover, the main control center analyses the received data, and if a certain slave node is abnormal, the neighbouring nodes should send abnormal messages of different degrees, and if there is not such activity, the neighbouring nodes probably have a problem.
In case of no safety issue, each of the solar LED lamp wireless sensor devices regularly performs self test operations/steps, which are as follow.
Step one, regular operation: each node regularly transmits a safety message to the relay station every 24 hours, and if a node is malfunctioned, the uploaded data of the relay station may have related message, so as to facilitate maintenance and repair. Regarding a damaged node, replacement thereof is only mechanical disassembling, and only coordinate data of longitude, latitude and altitude of the relay station, coordinate data of longitude, latitude and altitude of itself and a related operation program are provided for resetting the node.
Step two, calibration operation: a timer of each node is required to be calibrated, and regarding the bridge monitoring, requirement on synchronization of the timers of the nodes is more stringent, and a method thereof is that the relay station obtains a standard time from the cloud every a fixed time interval, and write the current standard time to the neighbouring slave nodes, and the slave nodes written with the standard time are changed to the master nodes to write the current standard time to the neighbouring slave nodes until the timers of all of the nodes are updated to the current standard time, so as to achieve a synchronization activity.
Possible Effects of Embodiments
Embodiment One: Single Tower Cable-stayed Bridge
A single tower cable-stayed bridge is constructed in a curved shape of streamline in collaboration with an image and concept of a sailing ship, a bridge span is about 164 meters, an average width of the bridge is 5 meters, a height of a bridge tower is 49 meters, a distance between a water (liquid) level in the harbour and the bottom of the bridge is about 12 meters.
The solar LED lamp wireless sensor devices respectively containing the three-axis accelerometer and an exposed liquid level ultrasonic sensor are disposed every other meter at both sides of the bridge and the bridge tower, and totally 426 solar LED lamp wireless sensor devices are installed. Fourth colors RGBW of the lamp of the device may achieve a multi color dimming function, which is not only used for lighting and decoration lighting, but is also used for monitoring a level change of river, a bridge tower vibration and a bridge deck vibration, and vibration peaks, off peaks of the past are recorded in a long-term, which becomes a main prevention mechanism of safety monitoring.
Embodiment Two: Monitoring of a Train Bridge
Regarding monitoring of the train bridge, a plurality of the solar LED lamp wireless sensor devices containing the three-axis accelerometer are installed on the bridge, and when a train passes by, 40 seconds of vibration is recorded, a frequency spectrum recorded by the accelerometer is 0.25-20 Hz, and a recording time of each sensor device is required to be synchronized.
Railway safety monitoring is another application of the invention, when the train is running at a high speed, deformation of railway may cause a disaster, so that deflection meters and thermometers are installed on the railway to detect whether the railway is displaced or sunk due to external force, or whether the railway is deformed due to a temperature variation. Moreover, the deflection meters and hydraulic gages are installed on railway embankment to detect whether the railway embankment is displaced or sunk.
Embodiment Three: Monitoring of Electric Tower, Monitoring of Electric Tower Landslide
Electric towers are distributed in remote mountainous areas in large numbers, and face blowing of strong winds over a long period of time, and the mountainous areas have a risk of earthquakes or landslides, so that an electric tower safety monitoring system is necessary. According to the invention, a plug and play wireless communication network is used, and by installing the solar LED lamp wireless sensor devices respectively containing an inclinometer at 8 positions on each of an upper layer and a lower layer of the electric tower (total 16 sensing points), a three-dimensional tilt status of the electric tower can be monitored in real-time 24-hour a day, and data is transmitted to the main control center through the wireless communication network in real-time, such that a supervisor can learn a tilt status of the electric tower without checking the electric tower onsite.
In summary, the invention provides a safety monitoring apparatus and system for bridge, building or structure, which has features of simple installation and setting, and can be used in long-time, and is neither in need of direct control of manpower, nor in need of power supply of a city power. The apparatus and system of the invention can be applied in wild, remote area, or long bridges, viaducts, urban rapid transit rails, railway tracks contacting towns, or even electric towers, mountain slopes, flood banks of river or sea, etc. to achieve a safety monitoring effect.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
Number | Date | Country | Kind |
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102210815 U | Jun 2013 | TW | national |
Number | Name | Date | Kind |
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20060155818 | Odenwald | Jul 2006 | A1 |
20070257625 | Brison | Nov 2007 | A1 |
20140167969 | Wedig | Jun 2014 | A1 |
Number | Date | Country | |
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20140361888 A1 | Dec 2014 | US |