Management method and management system

Abstract

This management method for managing an angle of a target object in order to maintain and manage the target object, which is held in a structure, includes: using a sensor attached to the target object to detect the angle of the target object for a predetermined period of time, and acquiring sensor data including a detected value of the angle, output from the sensor, and a detection time thereof (steps S208 to S212); and subjecting the acquired sensor data to frequency analysis to extract maintenance-related information (steps S214 to S216).

Description

Management method and management system

[0001] The present invention relates to a management method and management system, and a sensor device, and more particularly to a management method and management device for managing changes (such as abnormalities) in the state (angle, posture, etc.) of an object, and a sensor device used to measure the inclination angle of an object, etc. This application claims priority based on Japanese Patent Application Nos. 2022-211039 and 2022-211553, filed on December 28, 2022, the contents of which are incorporated herein by reference.

[0002] For example, in tunnels, jet fans are installed to ventilate the tunnel for the purposes of ensuring the driver's field of vision and reducing the carbon monoxide concentration inside the tunnel. To prevent the jet fans from falling, inspection vehicles are used to periodically inspect the suspension status of the jet fans by workers. However, this inspection is a complex task and difficult to perform frequently. To address this issue, Patent Document 1 discloses an invention that uses a sensor to detect whether the suspension status (holding status) of the jet fan is appropriate. In this invention, the sensor detects the tilt of the jet fan to determine whether the suspension status of the jet fan is appropriate.

[0003] However, jet fans suspended from the ceiling of a tunnel are subject to vibrations caused by passing vehicles and vibrations resulting from the operation of the jet fan. Therefore, simply detecting the tilt of the jet fan body, as in the invention described in Patent Document 1, makes it difficult to appropriately determine whether maintenance of the jet fan's suspension components is necessary. Furthermore, in fields such as civil engineering and construction, it is sometimes necessary to manage changes in the state (tilt angle, posture, etc.) of moving objects (objects), not just objects held by structures like the jet fan described above, to prevent them from falling or tipping over. Examples include the falling of a suspended load during slinging work or the tipping over of construction machinery such as a crane truck.

[0004] JP 2007-191942 A

[0005] According to a first aspect, there is provided a management method for managing changes in the angle of an object held on a structure, the management method including: detecting the angle of the object for a predetermined period of time using a sensor attached to the object; acquiring sensor data including the detected value of the angle and the time of detection output from the sensor; and performing frequency analysis of the acquired sensor data to extract maintenance-related information.

[0006] According to a second aspect, there is provided a management method for managing changes in the angle of an object, which monitors the difference between the initial value of the inclination angle of the object in a predetermined direction measured by a sensor attached to the object, and issues an alarm when the difference exceeds a predetermined threshold.

[0007] According to a third aspect, there is provided a management system for managing changes in the angle of an object held on a structure, comprising: a sensor device attached to the object and detecting the angle of the object; and a management device that detects the angle using the sensor device for a predetermined period of time and acquires sensor data output from the sensor device including the detected value of the angle and the time of detection, wherein the management device performs frequency analysis of the acquired sensor data to extract maintenance-related information.

[0008] According to a fourth aspect, there is provided a sensor device used to measure the inclination angle of an object, comprising a sensor unit including an angle sensor that measures the inclination angle of the object in a predetermined direction and a power supply unit, and a housing that houses the sensor unit, wherein a power switch is attached to the housing in a state where it is partially exposed to the outside, and the power switch switches from an off state to an on state when the housing is attached to the object, and power supply from the power supply unit to the angle sensor is started.

[0009] According to a fifth aspect, there is provided a management system for managing changes in the angle of an object, comprising a sensor device according to the fourth aspect attached to the object and an alarm device connected to the sensor device, wherein the sensor unit of the sensor device further has an arithmetic processing unit, and the arithmetic processing unit sets the inclination angle measured by the angle sensor when power supply from the power supply unit to the angle sensor starts as an initial value of the inclination angle, calculates the difference between the measured value of the inclination angle measured by the angle sensor after setting and the initial value, and when the difference exceeds a predetermined threshold, issues an alarm command to the alarm device.

[0010] According to a sixth aspect, there is provided a management system for managing changes in the angle of an object, comprising a sensor device and a management device according to the fourth aspect connected to each other via a network, and an alarm device connected to the management device, wherein the sensor device transmits a measurement standby command to the management device when the power switch is switched to the on state, and the management device receives the measurement standby command and, after instructing the sensor device to start measurement, starts acquiring angle data measured by the sensor device, sets the angle data acquired at the start of acquisition to the initial value of the inclination angle, and after setting, monitors changes over time in the difference between the angle data measured by the sensor device and the initial value, and when the difference exceeds a predetermined threshold, gives an alarm instruction to the alarm device.

[0011] According to a seventh aspect, there is provided a management system for managing changes in the angle of an object, comprising a sensor device attached to the object and detecting the angle of the object, a management device connected to the sensor device, and an alarm device connected to the management device, wherein the management device monitors the difference between the initial value of the inclination angle of the object in a predetermined direction measured by the sensor device, and when the difference exceeds a predetermined threshold, gives an alarm command to the alarm device.

[0012] According to an eighth aspect, there is provided a management method for managing an object held by a structure or moved by a drive unit, the management method including: detecting the angle of the object using a sensor attached to the object, acquiring sensor data including the sensor's detection information and the detection time, and monitoring the sensor data with different detection times to detect the state of the object.

[0013] According to a ninth aspect, there is provided a management system for managing an object held on a structure or moved by a drive unit, comprising: a sensor device attached to the object and detecting angle information of the object; and a management device to which the sensor device is connected via a communication network, wherein sensor data including the detection information of the sensor device and the detection time thereof is sent to the management device via the communication network, and the management device monitors the sensor data with different detection times to detect the state of the object.

[0014] 1 is a diagram illustrating an overall configuration of a management system according to a first embodiment. It is a block diagram illustrating an overall configuration of the sensor device of FIG. 1. It is a block diagram illustrating an overall configuration of the relay device of FIG. 1. It is a diagram illustrating a jet fan as a measurement target (object) of the sensor device, suspended from the ceiling of a tunnel. FIGS. 5(A) to 5(D) are diagrams for explaining frequency decomposition (frequency analysis) of a signal of a time change in the angle of a predetermined direction. It is a diagram illustrating a frequency spectrum waveform of the signal of FIG. 5(A). It is a flowchart corresponding to a processing algorithm according to a program executed by the CPU of the server. It is a flowchart corresponding to a processing algorithm according to a program executed by the CPU of the relay device. It is a diagram illustrating an overall configuration of a management system according to a second embodiment. It is a block diagram illustrating an example of the configuration of the sensor device of FIG. 9, illustrating a side view of the sensor device immediately before being fixed to an object. It is a block diagram illustrating an example of the configuration of the alarm device of FIG. It is a diagram for explaining slinging work performed in work of transporting heavy objects such as steel plates by a crane. It is a flowchart illustrating a processing algorithm executed according to a program by the processing unit of the sensor device. It is a flowchart illustrating a processing algorithm executed according to a program by the server 12. 16(A) and 16(B) are diagrams for explaining a modified example of the second embodiment, showing the side and rear views, respectively, of a crane truck.

[0015] First Embodiment A first embodiment will be described below with reference to FIGS. 1 to 8. FIG. 1 schematically illustrates the configuration of a management system 10 according to the first embodiment. The management system 10 includes a base station 14, a server 12 that also functions as a management device, and a mobile terminal 16, all of which are connected to each other via a wide area network (hereinafter abbreviated as "network") 13 such as the Internet, a relay device 40 connected to the base station 14 via mobile communication (e.g., 3G / (4G / LTE) / 5G communication), and a sensor device 18 wirelessly connected to the relay device 40. The communication method between the relay device 40 and the network 13, the server 12, and the mobile terminal 16 is not limited to the mobile communication method described above.

[0016] Communication between the sensor device 18 and the relay device 40 is possible via LPWA (Low Power Wide Area) wireless. LPWA wireless is a specific low-power wireless communication technology that is a communication method that achieves long-distance communication with low power consumption. However, the wireless method between the sensor device 18 and the relay device 40 is not limited to LPWA.

[0017] In this embodiment, a commonly used server computer is used as the server 12, but a cloud (computer) may also be used. The server 12 includes a CPU, ROM, RAM, HDD, and other storage devices (not shown). The CPU uses, for example, the RAM as a work area and executes various processing algorithms defined by various programs stored in the ROM, HDD, and other storage devices. Note that the configuration of the management device is not limited to that of this embodiment. The management device is not limited to hardware as in this embodiment, and may be software capable of executing at least the control functions and calculation functions for controlling the relay device 40 and the sensor device 18, for example.

[0018] The server 12 stores the relay device 40 and an application that controls the sensor device 18 via the relay device 40. The mobile terminal 16 can also control the relay device 40 by accessing the server 12.

[0019] As shown in the block diagram of Figure 2, the sensor device 18 includes a sensor unit 180 having an angle sensor 181, an arithmetic processing unit 182, a communication unit 183, a display operation unit 187, and a power supply unit 184 consisting of, for example, a battery, and a waterproof housing 185 that houses the sensor unit 180 therein.

[0020] The angle sensor 181, the communication unit 183, and the display operation unit 187 are connected to the arithmetic processing unit 182. The power supply from the power supply unit 184 to each of the angle sensor 181, the communication unit 183, and the display operation unit 187 is turned on and off under control of wireless communication from the relay device 40.

[0021] In this embodiment, a 2D MEMS (two-dimensional microelectromechanical system) tilt angle sensor is used as the angle sensor 181, for example. The 2D MEMS tilt angle sensor requires extremely low power consumption, in the microampere range, making it suitable for wireless applications. For example, the angle sensor 181 has two pairs of electrodes, each consisting of a fixed electrode and a movable electrode. Using the horizontal positional relationship between the electrodes as a reference, the sensor measures the amount of change in capacitance between the electrodes that accompanies a change in positional relationship due to tilt, converting this into an angle, and outputs tilt angle information in two directions. The angle sensor 181 may also have an ASIC built in.

[0022] The angle sensor is not limited to a 2D MEMS tilt angle sensor, and other types of 2D tilt angle sensors may be used. Furthermore, the angle sensor is not limited to a 2D tilt angle sensor, and may include a 3D tilt angle sensor or a combination of multiple 1D tilt angle sensors. As a 3D tilt angle sensor, for example, a 3D MEMS tilt angle sensor may be used. As a 3D MEMS tilt angle sensor, for example, a sensor incorporating two MEMS acceleration sensors with symmetrical output characteristics and an ASIC may be used.

[0023] The arithmetic processing unit 182 includes an ADC (Analog-to-Digital Converter) and an MCU (Micro Controller Unit). The ADC is a device such as an electronic circuit that converts an analog signal into a digital signal. In this embodiment, the ADC samples the intensity of the analog signal output from the angle sensor 181 at regular intervals and quantizes the value to convert it into a digital signal. This converts continuous data regarding the tilt angle into discrete data. The MCU is implemented as an integrated circuit equipped with a CPU (Central Processing Unit) as a central processing unit, a RAM (Random Access Memory) as a main storage device, and other peripheral devices (such as a ROM, an input / output circuit, and a timer circuit). The MCU executes a processing algorithm defined by a program stored in the ROM. The MCU controls the hardware installed in the sensor device 18.

[0024] The communication unit 183 performs wireless communication via the antenna 183 a. The communication unit 183 can use any medium, such as radio waves, light, or ultrasound, for communication, but here, LoRa (registered trademark) wireless, which is a type of LPWA wireless, is used as an example.

[0025] For example, the communication unit 183 transmits data output by the arithmetic processing unit 182 in accordance with an instruction from the arithmetic processing unit 182 to a predetermined output destination, in this case, to the relay device 40 .

[0026] The display operation unit 187 is made up of, for example, a touch panel, and functions as a user interface for inputting predetermined settings for the sensor device 18, and also as a display device for displaying information.

[0027] 2 and may be configured with only the angle sensor 181, the communication unit 183, and the power supply unit 184. In this case, the calculation processing unit 182 may be provided in another device such as the relay device 40.

[0028] 3 is a block diagram showing a schematic configuration of the relay device 40. The relay device 40 includes a control unit 41, a storage unit 42, a wireless communication unit 43, a network control unit 44, a display unit 45, and an input unit 46, all of which are connected to the control unit 41. An antenna 43a is connected to the wireless communication unit 43.

[0029] The control unit 41 is configured with, for example, a microprocessor and its peripheral circuits, and controls the entire relay device 40 and performs arithmetic processing.

[0030] The storage unit 42 is composed of nonvolatile memory such as ROM, rewritable nonvolatile memory such as flash memory, and volatile memory such as RAM. The ROM stores control programs and the like necessary for operating the relay device 40. The RAM stores the programs currently being executed by the control unit 41 and information necessary for their execution. The rewritable nonvolatile memory stores various setting data and the like.

[0031] The wireless communication unit 43 includes an LPWA wireless unit. The LPWA wireless unit communicates with the sensor device 18 via LPWA wireless (here, LoRa wireless). More specifically, the wireless communication unit 43 (LPWA wireless unit) operates intermittently or continuously, and receives information transmitted from the communication unit 183 (LPWA wireless unit) of the sensor device 18 via an antenna 43a. The antenna 43a transmits and receives radio waves.

[0032] The network control unit 44 communicates with the base station 14 via mobile communication (e.g., 3G / (4G / LTE) / 5G communication). The display unit 45 is formed of a liquid crystal display or the like, and the input unit 46 is provided with an input device such as a keyboard or a mouse. Instead of the display unit 45 and the input unit 46, a display operation unit may be provided which is formed of, for example, a touch panel and functions as a user interface for inputting predetermined settings for the relay device 40 and also functions as a display device for displaying information.

[0033] The relay device 40 configured in this way receives the data transmitted from the sensor device 18 in accordance with the above-mentioned program, and transmits the data to the server 12 via the base station 14 by mobile communication.

[0034] 4 shows a jet fan 100, which is the measurement target (object) of the sensor device 18. The jet fan 100 has a configuration in which, although not shown, a motor (electric motor) and axial fans attached to both sides of the motor's rotating shaft are installed inside a cylindrical casing 101. The center (axial center) of the motor's rotating shaft is approximately aligned with the central axis of the casing 101.

[0035] The casing 101 is supported (held) in a suspended state approximately horizontally (parallel to the XY plane in FIG. 4 ) on the ceiling wall 110a of the tunnel 110 by two pairs (four) of first connecting parts 102a, 102b, 102c, and 102d that primarily support the casing 101, and a pair of second connecting parts 104a and 104b that suppress the swinging of the casing 101. Here, the axial direction of the casing 101 shown in FIG. 4 is the Y-axis direction, the vertical direction perpendicular to the Y-axis is the Z-axis direction, and the direction perpendicular to the Y-axis and Z-axis is the X-axis direction.

[0036] The pair of first coupling portions 102a, 102b couple a pair of connection portions (ears) 106a (connection portion 106a on the far side of the page is not shown in Figure 4) provided on both side surfaces of casing 101 slightly to the left of the center in the axial direction (Y-axis direction) in Figure 4 to hanging hardware 105a, 105b fixed to the underside of ceiling wall 110a. The pair of first coupling portions 102c, 102d couple a pair of connection portions (ears) 106b (connection portion 106b on the far side of the page is not shown in Figure 4) provided on both side surfaces of casing 101 slightly to the right of the center in the axial direction (Y-axis direction) in Figure 4 to hanging hardware 105c, 105d fixed to the underside of ceiling wall 110a.

[0037] Each of the hanging fittings 105a, 105b, 105c, and 105d is fixed to the ceiling wall 110a with an anchor or the like (not shown).

[0038] The first connecting portions 102a to 102d are arranged so that the spacing between them increases from each connection portion 106a, 106b on the casing 101 toward each of the hanging fittings 105a to 105d on the tunnel 110 side, thereby minimizing shaking of the casing 101 in the axial direction (Y-axis direction) and the lateral direction (X-axis direction) perpendicular to the axial direction.

[0039] Meanwhile, second coupling portions 104a, 104b respectively couple connecting portions 107a, 107b provided at the top of casing 101 to hanging fittings 108a, 108b fixed to the underside of ceiling wall 110a. Second coupling portions 104a, 104b are attached to one end and the other end of the axial direction (Y-axis direction) of the top of casing 101. Hanging fittings 108a, 108b are fixed to ceiling wall 110a with anchors or the like (not shown). Hanging fittings 108a, 108b are provided on ceiling wall 110a outside and above both ends of casing 101 in the axial direction.

[0040] In this embodiment, the above-mentioned first connecting portions 102a to 102d, second connecting portions 104a and 104b, hanging fittings 105a to 105d, connection portions 106a and 106b, connection portions 107a and 107b, and hanging fittings 108a and 108b constitute a hanging system 200 (hanging member) that hangs the jet fan 100 from the ceiling wall 110a.

[0041] The sensor device 18 is fixed (attached) to the top surface of the casing 101 at the center in the axial direction. The sensor device 18 is fixed to the top surface of the casing 101 by, for example, the magnetic force of a magnet provided in the housing 185. Immediately after the sensor device 18 is fixed, the casing 101 is held parallel to the horizontal plane, and the sensor device 18 is initially set to output (0, 0) as the tilt angle (α, β) in two-dimensional directions, in this case, the rotation directions around the X-axis and Y-axis in FIG. 4 (θx direction, θy direction).

[0042] In this embodiment, the sensor device 18 is used to detect the tilt angle α in the θx direction and the tilt angle β in the θy direction of the jet fan 100 (casing 101). The sensor device 18 is fixed to the axial center of the top of the +Z side of the casing 101.

[0043] In this embodiment, the sensor device 18 detects the tilt angle α of the casing 101 in the θx direction and the tilt angle β in the θy direction from moment to moment, and the discrete data of the detected tilt angles is correlated with the data at the time of detection and transmitted as sensor data to the relay device 40 via LPWA wireless. The relay device 40 then transmits the sensor data to the server 12 via the base station 14 and the network 13 via mobile communication, either intermittently or continuously.

[0044] In this embodiment, which will be described in detail later, the server 12 calculates time-varying waveform data of the tilt angle (angle) from the sensor data (angle data) transmitted to the server 12 every moment, and then performs frequency analysis on this time-varying waveform data using a fast Fourier transform (FFT) technique. This will be briefly described below.

[0045] The sensor device 18 of this embodiment is used to efficiently determine when maintenance of the jet fan 100 is required by detecting whether or not there is a change in the holding state of the casing 101 over time by the suspension system 200 that suspends and supports the jet fan 100 (casing 101) on the ceiling wall 110a.

[0046] However, when an automobile (vehicle) travels on a roadway (not shown) within tunnel 110, for example, the travel of the automobile (vehicle) generates vibrations (vibrations due to vehicle travel) in tunnel 110 (including ceiling wall 110a), and the vibrations due to the vehicle travel are transmitted to casing 101 via first couplings 102a-102d and second couplings 104a, 104b. Furthermore, vibrations (jet fan drive vibrations) due to the rotation of the motor and axial fan of jet fan 100 while it is running are transmitted to casing 101. Therefore, in a normal state, i.e., when an automobile is traveling on the roadway within tunnel 110 and jet fan 100 is running, frequency analysis of the (time-series) detection signal (time-varying signal of the tilt angle of casing 101) of angle sensor 181 along a predetermined time axis reveals that the frequency components include the frequency components of the vibrations due to the vehicle travel and the frequency components of the jet fan drive vibrations. Therefore, in order to reliably detect whether or not the holding state of the casing 101 by the suspension system 200 changes over time under normal conditions, it is necessary to remove unnecessary frequency components such as vibration components caused by vehicle movement and jet fan driving vibrations from the time change signal of the inclination angle of the casing 101.

[0047] The aforementioned fast Fourier transform (FFT) is a method of frequency analysis. Frequency analysis is a method for understanding signal characteristics, and is performed in the frequency domain. Frequency analysis enables signal component analysis, which is difficult with analysis in the time domain. For example, if a signal showing the time change in angle of a predetermined direction as shown in FIG. 5A contains three frequency components, frequency decomposition of this signal will result in signals (periodic signals) of three frequency components as shown in FIGS. 5B to 5D.

[0048] The signal waveform in FIG. 5B has a frequency of f３ , the amplitude is R ３ The signal waveform in FIG. 5C is a sine wave with a frequency of f ２ , the amplitude is R ２ The signal waveform in FIG. 5(D) is a sine wave with a frequency of f １ , the amplitude is R １ These waveforms are obtained as a result of Fourier transform. As a result, the waveform (spectral information) shown in Figure 6 is obtained as the frequency spectrum waveform of the signal in Figure 5(A).

[0049] Therefore, in this embodiment, in order to obtain the spectral information shown in FIG. 6, the server 12 creates time-varying waveform data of the tilt angle based on the sensor data output from the sensor device 18 every moment and transmitted via the relay device 40, and then performs frequency analysis on this time-varying waveform data using the fast Fourier transform (FFT) technique.

[0050] Actual output data (tilt angle data) from the sensor device 18 is acquired for a predetermined time when a vehicle is traveling on the roadway within the tunnel 110 and the jet fan 100 is driven, and the resulting time-varying signal of the tilt angle can include a change component in the tilt angle due to vibration of the casing 101 caused by the traveling vehicle (frequency component of vibration due to vehicle traveling) and a change component in the tilt angle due to vibration of the casing 101 caused by driving the jet fan (frequency component of driving vibration of the jet fan), regardless of whether there is a change (deterioration) in the suspended holding state of the jet fan 100. Hereinafter, for convenience, the frequency of the frequency component of vibration due to vehicle traveling will be referred to as f ２ , the frequency of the frequency component of the jet fan driving vibration is f ３ Let's say.

[0051] frequency f ２ , f ３ can be obtained in advance by experiment as follows. This experiment is carried out while the jet fan 100 is held in the initial state by the suspension system 200 described above.

[0052] First, when there are no vehicles traveling on the roadway inside the tunnel 110, the jet fan 100 is driven, and output data from the sensor device 18 is acquired for a predetermined time at a predetermined sampling interval. The time-varying waveform of the inclination angle obtained from the sampling data is subjected to frequency analysis, and the frequency corresponding to the maximum spectrum in the frequency spectrum waveform obtained as a result is determined. This determined frequency is called f ３ Let's say.

[0053] Next, while the jet fan 100 is stopped, a predetermined number of vehicles, for example, 30 vehicles, pass under the jet fan 100, and output data from the sensor device 18 is acquired at a predetermined sampling interval. The waveform of the time change in the tilt angle obtained from the sampling data is subjected to frequency analysis to determine the frequency corresponding to the maximum spectrum in the frequency spectrum waveform. This determined frequency is called f ２ Let's say.

[0054] In addition, the frequency f ２ , frequency f ３ Either of these can be found first. ２ <f ３ It is known that...

[0055] Consider a normal state, that is, a state in which the jet fan 100 is in operation and a vehicle passes under the jet fan 100, and the jet fan 100 is maintained in its initial state by the suspension system 200. In this case, output data from the sensor device 18 is acquired at a predetermined sampling interval for a certain period of time, and the frequency spectrum waveform obtained from this sampling data as described above includes a frequency f ３ , f ２ The spectrum should include:

[0056] Next, consider a case where, in the above-mentioned normal state, a change occurs in at least a part of the suspension system 200 from its initial state, causing the holding state of the jet fan 100 to change (deteriorate) from its initial state. The change in the holding state of the jet fan 100 from its initial state means that some of the connecting parts have loosened (deteriorated holding state), and this deterioration in the holding state is also likely to cause the sampled value of the tilt angle of the casing 101 to vibrate over time. In this case, the above-mentioned frequency spectrum waveform, which is obtained from the result of frequency analysis of the time-varying waveform of the tilt angle obtained by sampling the output data of the sensor device for a predetermined time, includes a frequency f ３ , f ２ In addition to the spectrum of １ In other words, the frequency spectrum waveform contains the spectrum of frequency f ３ , f ２ Not only that, but also another frequency f １ If the signal includes the above, it can be inferred that a change from the initial state has occurred in at least a part of the suspension system 200. In this embodiment, based on this idea, the occurrence of a change from the initial state of the suspension system 200 is detected, and based on the detection result, a determination is made as to whether maintenance of the suspension system 200 is required.

[0057] Next, the operation of each part when performing maintenance management of the jet fan 100 using the management system 10 according to this embodiment will be described.

[0058] It is assumed that the jet fan 100 is suspended horizontally by the suspension system 200 so as to be substantially parallel to the ceiling wall 110a of the tunnel 110. The sensor device 18 is fixed to the top of the casing 101 (see FIG. 4). The frequency f ２ , f ３ It is assumed that the frequency components of the vibration caused by the running of the vehicle and the frequency components of the driving vibration of the jet fan do not necessarily coincide with each other in the θx direction and the θy direction, but in the following, the frequency components in either direction are assumed to be equal to the frequency f２ , f ３ It is assumed that

[0059] First, the maintenance manager accesses the server 12 via the mobile terminal 16 and instructs the server 12 to start maintenance management.

[0060] Fig. 7 shows a flowchart corresponding to a processing algorithm according to a program executed by the CPU of the server 12. The flowchart in Fig. 7 starts upon input of a command instructing the start of the above-mentioned maintenance management.

[0061] First, in step S202, the relay device 40 is instructed to start measurement. This instruction to start measurement is given through mobile communication (e.g., 3G / (4G / LTE) / 5G communication) via the base station 14. Prior to the start of mobile communication, communication is established between the server 12 and the relay device 40.

[0062] In the next step S204, the process waits for the start of measurement. Specifically, the process waits for a notification that measurement has started from the relay device 40. Then, when the notification that measurement has started is received from the relay device 40 via mobile communication, the process proceeds to the next step S206.

[0063] In step S206, a request for transmission of sensor data is made via mobile communication to relay device 40. As described above, the sensor data includes at least the measured values ​​of the tilt angles in the θx and θy directions and information on the time of measurement.

[0064] In the next step S208 to S210, a loop is repeated for a predetermined time T, in which sensor data is received and information on the tilt angles in the θx and θy directions (including the measurement values ​​and measurement times) is stored in a storage area in memory. It is desirable to provide a separate storage area for each direction. As a result, the measurement values ​​of the tilt angles in each direction for the predetermined time T are stored in chronological order in each storage area in memory.

[0065] When a predetermined time T has elapsed after the request to transmit sensor data, the determination in step S210 becomes positive, and the process proceeds to step S212, where the relay device 40 is instructed to end measurement via mobile communication.

[0066] In the next step S214, time-varying waveform data of the tilt angle in each direction is created based on the tilt angle information stored in chronological order in the respective storage areas in the memory. By the processing of this step S214, time-varying waveform data of the tilt angle over a predetermined time T, for example, time-varying waveform data similar to the time-varying waveform of the tilt angle (angle) shown in Figure 5(A) is obtained. Such time-varying waveform data is obtained for each of the tilt angles in the θx direction and the θy direction.

[0067] In the next step S216, the time-varying waveform data of the tilt angle in each direction is frequency-analyzed using FFT (Fast Fourier Transform), and frequency spectrum waveform data is created based on the frequency analysis results. Here, FFT refers to an algorithm for quickly calculating a Discrete Fourier Transform (DFT) on a computer.

[0068] By the process of step S216, the time-varying waveform data of the tilt angle for the predetermined time T is subjected to frequency analysis (frequency decomposition), and the frequency f ３ , f ２ From this waveform data, frequency spectrum waveform data (spectrum information) is obtained in which spectra for multiple frequencies are arranged in a coordinate system with the horizontal axis representing frequency and the vertical axis representing amplitude, similar to the frequency spectrum waveform data shown in Figure 6. Such spectrum waveform data is obtained in both the θx direction and the θy direction.

[0069] In the next step S218, it is determined whether or not maintenance of the jet fan 100 is required, in this case, inspection or repair of the suspension system 200. If the determination in step S218 is negative, the process proceeds to step S220.

[0070] The determination in step S218 is made based on the data of the frequency spectrum waveform in each direction as follows: Therefore, the data of the frequency spectrum waveform is an example of maintenance-related information.

[0071] For each of the θx direction and the θy direction, a frequency f ２ , f ３ As a result of this determination, it is determined whether or not a spectrum of a frequency other than frequency f is included in the frequency spectrum waveform in at least one of the θx direction and the θy direction. ２ , f ３ If a spectrum with a significant magnitude of a frequency other than ２ , f ３ If only one or both of the above spectrums are included, it can be determined that maintenance is not required.

[0072] In this case, the frequency f ２ , f ３ The spectrum with significant magnitudes of frequencies other than f is considered to be a spectrum that represents a change (deterioration) over time in the state of holding the jet fan by the suspension system 200, and the magnitude of the spectrum will differ depending on the degree of that change. Therefore, the frequency spectrum waveform in at least one direction is considered to include a frequency f ２ , f ３ The spectrum includes significant magnitudes of frequencies other than the frequency f ２ , f ３ It is also possible to determine that maintenance is required only when the magnitude of the spectrum of frequencies other than the above exceeds a predetermined threshold, and to determine that maintenance is not required in other cases.

[0073] Here, in step S218, in addition to determining whether or not the above-described maintenance of the suspension system 200 (inspection, repair, etc. of the suspension system 200) is necessary, it may also be determined whether or not there is a failure in the motor and the axial flow fan. ３This can be done based on the magnitude of the spectrum.

[0074] In step S220, the process waits for a waiting time WT to elapse. Here, the waiting time WT refers to a measurement pause time and is determined in advance. The waiting time WT can also be set to 0. Once the waiting time WT has elapsed, the process returns to step S202, and the loop processing (including determination) of steps S202 to S220 is repeated until the determination in step S218 is affirmative or the process is forcibly terminated. As a result, a series of processes for measuring the inclination angle by the sensor device 18 for a predetermined time T and determining whether maintenance is required using the sensor data from the sensor device 18 are repeated at intervals of the waiting time WT.

[0075] On the other hand, if the determination in step S218 is affirmative, the process proceeds to step S222, where warning information is sent to the mobile terminal 16 to inform the mobile terminal 16 that maintenance of the suspension system 200 for the jet fan 100 (and the jet fan 100) is required, and the series of processes is then terminated. As a result, for example, a message "Maintenance Required" is displayed on the display of the mobile terminal 16. An alarm sound may also be emitted along with the message. Upon receiving the warning information, a worker will immediately rush to the site to perform maintenance, but prior to the worker's arrival at the site, passage below the jet fan may be prohibited as a fail-safe measure. In this case, the measurement information obtained from the sensor device 18 may be divided into multiple levels, for example, according to the amount of displacement, and passage may be prohibited only when the risk of falling is at a high level. For example, when the frequency f ２ , f ３ The magnitude of the spectrum of frequencies other than the above may be determined to which of a number of levels, for example, classified according to the degree of risk of falling, and passage may be prohibited only when the degree of risk of falling is at a high level.

[0076] Fig. 8 shows a flowchart corresponding to a processing algorithm according to a program executed by the CPU of control unit 41 of relay device 40. The flowchart of Fig. 8 starts when the exchange of commands for establishing communication between relay device 40 and server 12 is completed, prior to the processing of step S202 described above.

[0077] First, in step S302, the process waits for a command to start measurement to be input. When the command to start measurement is given from the server 12 (see step S202 above), the process proceeds to step S304, where the power to the sensor device 18 is turned on via LPWA wireless communication, and then the process proceeds to the next step, S306.

[0078] In step S306, the sensor device 18 is instructed to start measurement via LPWA wireless communication and is requested to transmit sensor data. In the next steps S308 to S310, a loop is performed in which the sensor data is repeatedly received and transferred to the server 12 until an instruction to end measurement is received. The sensor data is received via LPWA wireless communication, and transferred to the server 12 via mobile communication.

[0079] When the server 12 issues an instruction to end the measurement (see step S212 described above), the process proceeds to step S312, where the power to the sensor device 18 is turned off via LPWA wireless communication, and the series of processes is then terminated.

[0080] The sensor device 18 starts measurement in response to the instruction to start measurement in step S306 above, and continues to transmit sensor data including data on the tilt angles in two directions (discrete data) and the measurement times to the relay device 40 via LPWA wireless until the power is turned off.

[0081] The management system 10 according to the present embodiment described above is a management method for managing changes in the angle of an object (e.g., a jet fan 100) held in a structure (e.g., a tunnel 110). The management method includes: detecting the angle of the object (e.g., a two-dimensional tilt angle) for a predetermined period of time using a sensor device 18 (sensor) attached to the object; acquiring sensor data (angle data) including the detected angle value and the time of detection output from the sensor device 18 (steps S208 and S210); and extracting maintenance-related information by performing frequency analysis on the acquired sensor data (steps S214 and S216). The extracted maintenance-related information includes frequency spectrum waveform data obtained as a result of the frequency analysis. Furthermore, the management system 10 determines whether maintenance is required based on the maintenance-related information (step S218). Note that, as an example, the jet fan 100 is suspended from the ceiling wall 110 a of the tunnel 110 by the suspension system 200; however, the present invention is not limited to this configuration; the jet fan 100 may be fixed to the ceiling wall 110 a of the tunnel 110. The management method according to this embodiment is used for the maintenance management of an object held in a structure, and therefore can also be expressed as a method for maintaining and managing an object.

[0082] In this embodiment, the sensor device 18 is attached to the casing 101 of the jet fan 100 and detects the angle (tilt angle in a two-dimensional direction) of the casing 101. The frequency spectrum waveform data included in the maintenance-related information is obtained as follows: That is, sensor data (angle data) including the detected value of the tilt angle from the sensor device 18 and the time of detection thereof is received via wireless communication (including LPWA wireless communication and mobile wireless communication), time-varying waveform data of the tilt angle in a two-dimensional direction is created based on the received sensor data, and the time-varying waveform data is frequency-analyzed using a Fourier transform (here, FFT), thereby obtaining the analysis result (frequency spectrum waveform).

[0083] According to the management system 10 of this embodiment, if maintenance is required, such as when some abnormality occurs in the suspension and holding state of the jet fan 100, the server 12 determines that maintenance is required and notifies the mobile terminal 16 of warning information that maintenance is required for the suspension system 200 of the jet fan 100. This notification causes, for example, a message "Maintenance Required" to be displayed on the display of the mobile terminal 16. Therefore, according to this embodiment, there is no need for periodic visual inspection work by an operator, which was previously performed by restricting vehicle passage.

[0084] In the above embodiment, the management system 10 is described as being used for the maintenance management of an object held in a structure. However, this is not limited to this. Maintenance management, including automatic determination of the need for maintenance of an object held in a structure, can be achieved using the sensor device 18 and the relay device 40, similar to the above embodiment, without using the base station 14, the network 13, and the server 12. For example, the control unit 41 (CPU) of the relay device 40 may wirelessly receive sensor data (angle data) including a detected angle of the object from the sensor device 18 and the time of detection for a predetermined period of time T, similar to the server 12 in the above embodiment, perform frequency analysis on the received angle data, extract maintenance-related information including frequency spectrum waveform data, and determine the need for maintenance based on the extracted maintenance-related information. This can be easily achieved by rewriting the program executed by the control unit 41 (CPU). In this case, the relay device 40 may notify the mobile terminal 16 of the need for maintenance by issuing a command. Alternatively, or in addition to this, the control unit 41 of the relay device 40 may display the need for maintenance on the display unit 45.

[0085] Alternatively, a sensor module having the same overall configuration as the sensor device 18 of the above embodiment and having an arithmetic processing unit 182 with an FFT function unit may be provided in place of the sensor device 18. In such a case, the arithmetic processing unit 182 of the sensor module creates time-varying waveform data of the tilt angle in two-dimensional directions based on sensor data acquired for a predetermined time T, similar to the server 12 of the above embodiment, and performs frequency analysis of the time-varying waveform data using a Fourier transform (in this case, FFT) to create frequency spectrum waveform data obtained from the analysis results. In this case, the determination of whether maintenance of the suspension system 200 is required based on the frequency spectrum waveform data may be made by the arithmetic processing unit 182 of the sensor module, or may be made by an external device connected to the sensor module via wireless communication, such as the relay device 40 or the server 12. In either case, it is desirable for the sensor module, relay device 40, or server 12 to notify the mobile terminal 16 that maintenance of the suspension system 200 is required and to display, for example, "Maintenance Required" on the display screen. The sensor data output from the sensor device 18 is not limited to the measurement value of the angle of the angle sensor 181 itself, but may be data including as measurement information other physical quantities substantially equivalent to the angle, such as a positional deviation (displacement) of the measurement point obtained by calculation using trigonometric functions (sine, tangent, cosine, etc.). As is clear from the above description of the 2D MEMS sensor, the sensor device 18 (angle sensor 181) measures the tilt angle of the object with respect to the horizontal plane, i.e., the tilt angles around each of two orthogonal axes (e.g., the X-axis and the Y-axis) in the horizontal plane (tilt angle in the θx direction and tilt angle in the θy direction), which can also be said to measure the tilt angles in two directions with respect to the normal to the horizontal plane (i.e., the vertical axis).

[0086] In the above embodiment, the necessity of maintenance of the suspension system 200 of the jet fan 100 is mainly determined. However, the amplitude of the sine wave of the frequency component of the driving vibration of the jet fan, that is, the frequency f ３Based on the magnitude of the spectrum, it may be possible to determine whether or not an abnormality or failure has occurred in the motor and / or the axial flow fans attached to both sides of the rotating shaft of the motor.

[0087] In addition, when using the sensor device 18 to monitor changes over time in the holding state of road accessories such as the jet fan 100 over a long period of time, it is necessary to supply power (power feeding) to the sensor device 18.Possible countermeasures in this case include power feeding using a MEMS vibration generator, wireless power feeding (contactless power feeding) that transmits power using the induced magnetic flux generated between the electromagnetic induction type power transmitting side and power receiving side, solar power generation, or wired LAN power feeding using a LAN cable.

[0088] In the above embodiment, the jet fan 100 suspended from the ceiling of the tunnel 110 is used as the object, and a case has been described in which a determination is made as to whether or not maintenance of the object is required. However, the object of the management system 10 according to the above embodiment is not limited to this. The object may be any road accessory that is attached to a structure, and may be a jet fan, a duct-type ventilation system, a guide board, a road sign, etc. In addition to tunnels, the structure may also include various structures installed on roads, such as viaducts, gantries, and poles. Here, if the object is a road accessory that does not have a motor, such as a guide board or a road sign, no drive vibration is generated by motor drive, and therefore the need for maintenance of the object can be determined based on the frequency f of the frequency component of the vibration caused by vehicle travel. ２ is calculated in advance in the same manner as above, and the frequency f ２ Whether there is a spectrum with a significant magnitude of frequencies other than f ２ Based on the magnitude of the spectrum with significant magnitude of frequencies other than the above, it is possible to determine whether or not maintenance is required for the target object, such as a guide board or road sign.

[0089] Furthermore, in the above embodiment, a case where an object is suspended and supported on a structure has been described, but the management system and management method of the above embodiment can also be applied to a structure that supports an object from below. Furthermore, in the above embodiment, a tunnel 110 (an example of a road structure) that holds a jet fan 100 has been taken up as the structure, but the management system and management method of the above embodiment can also be applied to structures other than road-related structures, such as structures that support signs for supermarkets, convenience stores, etc.

[0090] It is also possible to detect the two-dimensional tilt of an object suspended from the ceiling by a suspension member using a displacement sensor that detects changes in the distance from the ceiling, but in this case, at least four displacement sensors are required. In contrast, in the above embodiment, the two-dimensional tilt angle of the object can be detected using a single angle sensor 18.

[0091] So far, a management system and a management method for managing changes in the angle of an object held by a structure have been described, in order to maintain and manage the object. Specifically, in order to appropriately determine the timing of maintenance, time-varying waveform data (detection signal) of the object's tilt angle (angle) is decomposed in the frequency domain to remove noise components other than the target component and extract the target component, i.e., the component of change in the tilt angle of the object over time due to changes in the holding state of the object by the structure. However, the management system and the management method for managing changes in the angle of the object are not limited to this. As a second embodiment described below, a management system and a management method for managing changes in the angle of the object may also be considered, which uses the results of analyzing changes in the tilt angle (angle) of the object in the time domain to detect in advance the risk of the object falling.

[0092] Second Embodiment A second embodiment will be described below with reference to FIGS. 9 to 16B. Here, components identical or equivalent to those in the first embodiment described above will be designated by the same reference numerals, and their description will be omitted where appropriate. This second embodiment relates to a method for managing changes in the angle of an object, which monitors the change in the object's inclination angle from a reference state at any given time, e.g., an initial state, in order to detect in advance the risk of the object falling. FIG. 9 schematically illustrates the overall configuration of a management system 1010 suitable for implementing the management method according to this second embodiment. The management system 1010 includes a server 12, which also functions as a management device, a mobile terminal 16, a sensor device 18, and an alarm device 50, all of which are connected to one another via a network 13, such as the Internet.

[0093] The mobile terminal 16 is carried by a worker at the site. However, the mobile terminal 16 does not necessarily have to be provided.

[0094] In the second embodiment, the management device is configured by the server 12, but is not limited to this. The management device may be either hardware or software, and only needs to have at least a configuration (or function) that can calculate the initial value of the tilt angle of the measurement object and the difference between the initial value and the measured value based on the output of the sensor device 18.

[0095] As shown in FIG. 10 , the sensor device 18 includes a sensor unit 180 having an angle sensor 181, a processing unit 182, a communication unit 183, a display / operation unit 187, and a power supply unit 184, such as a battery, similar to the sensor device according to the first embodiment, and a waterproof housing 185 that houses the sensor unit 180. However, in the sensor device 18 according to the second embodiment, a power switch 186 is provided in the sensor unit 180, and the power supply from the power supply unit 184 to each component of the sensor unit 180 can be turned on and off by operating the power switch 186. The power switch 186 is attached to the housing 185 with a portion of it exposed to the outside from the bottom surface of the housing 185. In the second embodiment, a normally open push button switch is used as the power switch 186. As shown in FIG. 11 , the tip of a button portion 186 a of the power switch (push button switch) 186 is exposed from the bottom surface of the housing 185. The contacts of the switch 186 are configured to close when the tip of the button portion 186a is pressed into a position where it is approximately flush with the bottom end of the housing 185. In the second embodiment, when the sensor device 18 is removed from the object, the button portion 186a of the power switch 186 returns to its original position (home position) by the biasing force of a spring (not shown), the contacts open, and the supply of power from the power supply unit 184 to each unit of the sensor unit 180 is stopped.

[0096] In the second embodiment, the communication unit 183 is configured as a wireless communication unit that performs wireless communication. However, the communication unit 183 is not limited to the wireless configuration and may be at least partially wired. Furthermore, the sensor unit 180 is not limited to the configuration shown in FIG. 10 . It may be configured with only a portion of the configuration shown in FIG. 10 , such as the angle sensor 181, the communication unit 183, and the power supply unit 184. In this case, the angle sensor 181 and the communication unit 183 do not need to be integrated; it is sufficient that the angle sensor 181, i.e., the sensor device 18, has the function of measuring angle information at the installation location. For example, the angle sensor 181 and other units (including the arithmetic processing unit 182, etc.) may be connected via a wireless or wired communication line, and measurement data from the angle sensor 181 may be output to the other units via the communication line. However, if the push button switch 186 described above is used, it is necessary to adopt a configuration in which power is supplied to the angle sensor 181 via the push button switch 186. Furthermore, the functions of the other units described above may be provided by other terminals connected to the network 13.

[0097] In the second embodiment, a 2D MEMS tilt angle sensor that outputs information on tilt angles (α, β) in two directions (θx direction and θy direction) is used as the angle sensor 181. Here, the θx direction and the θy direction are tilt directions around the X-axis and the Y-axis of the three-dimensional orthogonal coordinate system shown in FIG.

[0098] The arithmetic processing unit 182 includes an ADC and an MCU, as described above. Note that instead of providing the arithmetic processing unit 182, an ASIC built into the angle sensor 181 may also have the functions of the arithmetic processing unit 182.

[0099] An example of a structure for attaching the sensor device 18 to an object will now be described with reference to Fig. 11. Fig. 11 shows a side view of the sensor device 18 immediately before being fixed to an object (for convenience, referred to as an object 1100).

[0100] The bottom of the housing 185 has multiple recesses formed therein, and permanent magnets 190 are disposed in each recess. When the sensor device 18 is attached to the object 1100, the magnetic force of the multiple permanent magnets 190 magnetically attracts the sensor device 18 to the object 1100. A magnetic shield member 189 is provided near the bottom of the housing 185. The number and shape of the permanent magnets are not particularly important, and the shape of the recesses formed in the bottom of the housing 185 need only allow the permanent magnets to be disposed therein. In the state immediately before the sensor device 18 is attached (fixed) as shown in FIG. 11 , the contacts of the power switch (push button switch) 186 are in the OFF state. However, after the sensor device 18 is attached (fixed), the button portion 186 a is pressed into the housing 185, causing the bottom end of the housing 185 to abut against the object 1100, turning the contacts on. The method of fixing the sensor device 18 is not limited to magnetic adsorption using a magnet, but may also be mechanical fixation using screws or clamps, or vacuum adsorption using a vacuum chuck or the like.

[0101] 12, the alarm device 50 includes a control unit 51, a communication unit 52, a speaker 53, and a display unit 54, as well as a waterproof housing 55 that houses these components. In the second embodiment, the communication unit 52 is configured as a wireless communication unit that performs wireless communication, but the communication unit 52 is not limited to being wireless and may be wired.

[0102] The control unit 51 is composed of a microcontroller and generates an alarm sound from the speaker 53 based on an externally input alarm command. That is, the control unit 51 provides the speaker 53 with an electrical signal representing a predetermined sound based on the alarm command, and the speaker 53 converts the provided electrical signal into a physical sound and emits it. The alarm sound may be a predetermined sound such as that emitted from a siren or buzzer, or may be a voice message representing the warning content. The display unit 54 is an LCD or other display that displays an image corresponding to a display command from the control unit 51. For example, the display unit 54 displays the warning content in text. The alarm device may also be a device that has a light-emitting element that lights up or flashes and issues an alarm using light.

[0103] The communication unit 52 is connected to the network 13. That is, in the second embodiment, the alarm device 50 is connected to the server 12 and other terminals via the network 13. However, this is not limiting, and the alarm device 50 (its communication unit 52) ​​may be connected to the server 12 without going through the network 13.

[0104] FIG. 13 is a diagram illustrating a slinging operation performed using a slinging jig in an operation to transport a heavy object (carried object) such as a steel plate by a crane (not shown). For the slinging operation, as shown in FIG. 13 , a slinging jig 61 is used, which includes a wire 62 that can be suspended from a crane hook 71 and a pair of hooks 64 attached to both ends (lower ends) of the wire 62. Specifically, during slinging, two slingers 72a manually support each of the pair of hooks 64 disposed on either side of the object (also referred to as a hoisted load) 60 on a platform 74, while a crane handler 72b operates the crane to lift the object 60. Therefore, when the object 60 is lifted and moved upward, there is a risk that the object 60 may lose balance, tilt, and fall, especially immediately after it leaves the platform 74. This constantly poses a risk of injury to the slingers 72a due to the falling object 60.

[0105] In the second embodiment, as shown in Fig. 13, the sensor device 18 is fixed (attached) to the transported object (hanging load) 60 by magnetic attraction before the transported object 60 is lifted, thereby preventing the above-mentioned situation in which the slinger 72a is injured due to the drop of the transported object 60. This will be explained below.

[0106] FIG. 14 shows a flowchart corresponding to a processing algorithm executed in accordance with a program by the CPU of the arithmetic processing unit 182 of the sensor device 18 used in slinging work.

[0107] The processing algorithm shown in the flowchart of Fig. 14 starts, for example, when the sensor device 18 is attached to the transported object (hanging load) 60 by magnetic attraction, the power switch 186 is turned on, and power supply from the power supply unit 184 to each unit of the sensor device 18 is started. The sensor device 18 is attached to the transported object 60 by one of the slingers 72a. The start condition of the processing algorithm shown in the flowchart of Fig. 14 is not limited to the start of power supply by turning on the power switch as described above, but can be determined arbitrarily in advance.

[0108] First, in step S102, a power-on notification command is sent to the server 12 via the network 13. In the next step S104, the process waits for an instruction to start measurement. Then, as will be described later, when a command to start measurement is input from the server 12, the process proceeds to step S106.

[0109] In step S106, the angle sensor 181 is instructed to start measurement. In practice, at this time, it is desirable to display a message on the screen of the display operation unit 187 indicating that measurement is about to start. This allows the slinger 72a to confirm that measurement is about to start, and after confirmation, to instruct the crane handler 72b to start the lifting operation. However, it is not necessary to display a message on the screen of the display operation unit 187 indicating that measurement is about to start. In this case, the slinger 72a may instruct the crane handler 72b to start the lifting operation after a certain period of time has elapsed since the sensor device 18 was attached to the transported object 60. Upon receiving the instruction to start the lifting operation from the slinger 72a, the crane handler 72b begins the lifting operation of the transported object (hanging load) 60 using the crane.

[0110] In the next step S108, angle information (tilt angle information) measured by the angle sensor 181 is acquired, and then in step S110, sensor data is created based on the acquired angle information and transmitted to the server 12. In this embodiment, the sensor data is a single piece of data that includes not only the angle information but also information on the measurement time. Here, a single piece of data may include multiple pieces of information that are linked to each other. In this specification, the sensor data may also be referred to as angle data, as appropriate. Note that the angle information may be other physical quantities that are substantially equivalent to an angle, such as measurement information such as the positional deviation (displacement) of the measurement point described above.

[0111] In the next step S112, it is determined whether or not the measurement should be terminated, and if this determination is negative, the process returns to step S108, and thereafter, the loop process (including determination) from step S108 to step S112 is repeated until the determination in step S112 is positive. Here, the determination in step S112 is made based on whether or not an instruction to terminate the measurement has been received from the server 12 (or another terminal device connected to the network 13).

[0112] If the determination in step S112 is positive, the series of processes ends. However, when the sensor device 18 is used for rigging work, a situation in which the determination in step S112 is positive does not normally occur.

[0113] 15 shows a flowchart corresponding to a processing algorithm executed by the CPU of the server 12 according to a program when managing the inclination angle of the transported object 60 during slinging work and the subsequent transportation of the transported object 60. The processing algorithm corresponding to the flowchart of FIG. 15 is started when the server 12 receives the above-mentioned power-on notification command from the sensor device 18.

[0114] First, in step S1002, the count value n of a counter indicating the number of times a power-on command has been received from the sensor device 18 is incremented by 1 (n←n+1). The count value n is initially set to "0." The count value n is stored in a non-volatile memory, such as a flash memory or an EEPROM. Therefore, by checking the count value n of the counter, it is possible to check, whenever necessary, the number of times the sensor device 18 has been powered on, i.e., the number of times the sensor device 18 has been attached to an object (the number of times it has been replaced).

[0115] In the next step S1004, the sensor device 18 is instructed to start measurement. As a result, the determination in the above-mentioned step S104 becomes positive, and a series of measurement processes (steps S106 to S112) is started on the sensor device 18 side.

[0116] In step S1006, the process waits for sensor data (angle data) to be sent from the sensor device 18. When the sensor data (angle data) is sent, the process proceeds to step S1007, where the sensor data (angle data) is received, and then the process proceeds to step S1008.

[0117] In step S1008, it is determined whether the received angle data is the initial data. If it is the initial data, the process proceeds to step S1010. In step S1010, the angle included in the received angle data is set as the initial value of the tilt angle, and then the process proceeds to step S1012. Note that it is preferable to set the initial value before the measurement target (object) starts moving. In addition, the instruction to start measurement does not necessarily have to be issued by the server 12. For example, it may be issued simultaneously with the power switch 186 of the sensor device 18 being turned on, or it may be issued by the worker installing the sensor device 18 via the display operation unit 187.

[0118] On the other hand, if the determination in step S1008 is negative, that is, if the received angle data is not the first, that is, if the data is received for the second time or later, the process proceeds to step S1012.

[0119] In step S1012, the difference between the angle (tilt angle) included in the sensor data (angle data) received in step S1007 and the initial value of the tilt angle is calculated, and then the process proceeds to step S1014. If step S1010 has been executed, the difference calculated in step S1012 is 0. In step S1014, it is determined whether the difference is greater than a predetermined threshold value, and if the determination here is negative, the process returns to step S1006, and the loop processing (including determination) of steps S1006 to S1014 is repeated.

[0120] On the other hand, if the difference is greater than the threshold, i.e., if the change in the measured inclination angle from the initial value exceeds a predetermined threshold, it is determined that there is a high probability that the transported object (load) 60 will lose balance and fall. The process proceeds to step S1016, instructs the alarm device 50 to issue an alarm, and then terminates the series of processes. If the threshold is set to an inappropriately small value, an alarm will be issued even for slight swaying of the suspended load 60 that does not result in a fall. Conversely, if the threshold is set to an extremely large value, an alarm will not be issued even if the suspended load 60 actually falls. Therefore, in this embodiment, an appropriate value is set based on the results of experiments or simulations. An alarm may be issued not only when the change in the measured inclination angle from the initial value exceeds the predetermined threshold, but also before the threshold is exceeded. Alternatively, the threshold may be set to a value determined by the above-mentioned experiments or the like before the transported object (load) 60 loses balance and falls, i.e., a value before (just before) the transported object (load) 60 loses balance.

[0121] The alarm is issued by the control unit 51 of the alarm device 50 according to a program. The control unit 51 of the alarm device 50 may issue a loud sound (such as a siren) or an audio message such as "Hanged load falling, run away" from the speaker 53, or may simultaneously display a warning message on the screen of the display unit 54. Note that the method of issuing the alarm (or warning) is not limited to sound or image display, and light may be used instead of or in combination with sound or image display. For example, the alarm device 50 may be provided with a light-emitting unit that lights up or flashes, such as a rotating light that emits a flashing light warning.

[0122] Other possible warning methods besides sound, image display, and light include vibration, email, telephone, etc. For example, when the control unit 51 of the alarm device 50 generates a sound from the speaker 53, it may instruct the mobile terminal 16 via the network 13 to vibrate the vibrator, or may send an email or make a phone call to the mobile terminal 16, etc. Of course, when the server 12 instructs the alarm device 50 to issue an alert, it may also send an email or make a phone call to the mobile terminal 16, etc. In this case, the mobile terminal 16, etc. functions as the alarm device.

[0123] As described above, the sensor device 18 according to the second embodiment includes a sensor unit 180 including an angle sensor 181 that measures the tilt angle of an object in a predetermined direction, a power supply unit 184, and other components (e.g., an arithmetic processing unit 182), and a housing 185 that covers the sensor unit 180. A power switch 186 is attached to the housing 185 while being partially exposed to the outside. The power switch 186 switches from an off state to an on state when the housing 185 is attached to the object, and power supply from the power supply unit 184 to each component of the sensor unit 180, including the angle sensor 181, begins. Therefore, the sensor device 18 according to the second embodiment does not require operation of the power switch 186 when attaching the sensor device 18 to the object. In addition, the second embodiment employs magnetic attraction using a permanent magnet 190 as a means for attaching the sensor device 18 to the object. This allows the sensor device 18 (housing 185) to be attached to the object with a single touch by magnetic attraction.

[0124] The management system 1010 according to the second embodiment includes a sensor device 18, a server 12, an alarm device 50, and other terminals (e.g., a mobile terminal 16), all connected via a network 13. When the sensor device 18 is attached to a transported object 60, the sensor device 18 transmits a power-on notification command (measurement standby command) to the server 12 when the power switch 186 is switched to the on state. The server 12 receives the power-on notification command, starts the algorithm of Fig. 15, and instructs the sensor device 18 to start measurement (step S1004). After that, the server 12 starts acquiring angle data measured by the sensor device 18 and sets the acquired angle data as an initial value for the inclination angle (steps S1008 and S1010). After the setting, the server 12 monitors the difference between the angle data measured by the sensor device 18 and the initial value (steps S1012 and S1014). When the difference exceeds a threshold (Yes in step S1014), the server 12 instructs the alarm device 50 to issue an alarm (step S1016). Therefore, according to the management system 1010 of the second embodiment, a management method for managing changes in the inclination angle of an object is realized, which includes monitoring the difference between the initial value of the inclination angle of the object in a predetermined direction measured by a sensor device 18 attached to the object, which is the transported object (suspended load) 60, and issuing an alarm when the difference exceeds a predetermined threshold as a result of the monitoring.

[0125] Therefore, according to the management system and management method of the second embodiment, by responding to an alarm and stopping the work or evacuating before the transported object (suspended load) 60 loses balance and falls during the rigging work of the transported object 60 or during subsequent transport work by crane, it is highly likely that man-made disasters caused by the fall of the transported object 60 can be prevented.

[0126] <<Variant Example>> This variant example relates to a case where the sensor device 18 is used to manage the tilt angle of a construction machine, for example, a crane truck 80 as shown in FIGS. 16(A) and 16(B), in order to detect in advance the occurrence of tipping over.

[0127] Figure 16(A) shows the side of the crane truck 80, and Figure 16(B) shows the rear of the crane truck 80. As shown in Figures 16(A) and 16(B), pairs of outrigger devices 82 are provided in pairs in the vehicle width direction at the front and rear of the vehicle body of the crane truck 80.

[0128] A pair of outrigger devices 82 provided at the rear of the vehicle body are arranged symmetrically on the left and right, and each includes a slide beam 84 of the same configuration that can be extended and retracted in the vehicle width direction, and a jack 86 attached to the tip of the slide beam 84.

[0129] As can be seen from the positional changes of the jack 86 indicated by the solid and two-dot chain lines and the double-headed arrow c in Figure 16(B), the slide beam 84 can be extended and retracted in the vehicle width direction so as to be able to set the slide beam 84 between a retracted state and an extended state. The jack 86 is a hydraulic jack having a cylinder 86a and a piston rod 86b that can be raised and lowered along the longitudinal direction of the cylinder 86a. The piston rod 86b can be raised and lowered so as to be able to set the slide beam 84 between a retracted state and a ground-contact state, as indicated by the double-headed arrow d in Figure 16(B).

[0130] The pair of outrigger devices 82 on the front side of the vehicle body are configured in the same manner as the outrigger devices on the rear side of the vehicle body.

[0131] At construction sites, etc., the boom 83 of a crane truck 80 is rotated (pivoted) in a predetermined direction via a swivel 81 and then extended diagonally upward (or directly upward) to perform necessary work. Prior to the start of work, the slide beams 84 of the four outrigger devices 82 (front, rear, left, and right) are extended outward in the width direction of the vehicle, and the lower ends (pedestals) of the piston rods 86b of the jacks 86 are pressed against the ground (and, if necessary, the vehicle body is raised a predetermined amount), thereby preventing the crane truck from tipping over. However, there are cases where the crane truck tips over, for example, when the boom 83 is rotated with a load hoisted by the crane. Causes of this include the outrigger devices (together with the decking) collapsing on soft ground, the load being too heavy, or operator error.

[0132] In this modification, the sensor device 18 is attached to the slide beam 84 of at least one outrigger device 82 by magnetic attraction before work begins. In this modification, the slide beam 84 is the object to which the sensor device 18 is attached, and the crane truck 80 is the driving unit (moving device) that moves the object. This modification also uses the management system 1010 described in the second embodiment. Therefore, after the sensor device 18 is attached to the slide beam 84, the sensor device 18 and the server 12 basically operate in the same manner as in the second embodiment. The server 12 monitors the magnitude relationship between the amount of change in the tilt angle of the slide beam 84 from its initial value (the aforementioned difference) and a predetermined threshold value. If the amount of change in the tilt angle from the initial value exceeds the threshold value, the alarm device 50 issues an alarm. A simulation or experiment regarding the tipping of a crane truck is conducted in advance to determine the extent to which the tilt angle measured by the sensor device 18 must change from its initial value (the value in the initial state) before the crane truck tips over, i.e., the limit value of the difference in tilt angle that causes tipping, and the threshold value is set to a value that takes a safety factor into account. Here, there are two types of outrigger devices, H-type and X-type, and the above initial values ​​differ for each type. Therefore, the limit value for the difference in tilt angle at which the crane vehicle will tip over differs for each type. Therefore, it is desirable to set a threshold value according to the type of outrigger device. Alternatively, the threshold value may be set according to the type with the smallest limit value for the difference. In this way, the management system 10 manages the change in the tilt angle of the slide beam 84, and the alarm device 50 issues an alarm before the vehicle body tips over, thereby increasing the probability of preventing unexpected accidents caused by the vehicle body tipping over.

[0133] Furthermore, crane work may be performed while the vehicle is being moved within the same work site. In such cases, particularly at work sites with poor ground and / or narrow spaces, work procedures require the outrigger devices 82 to be retracted before the move and extended after the move. In such cases, the sensor device 18 must be detached from the slide beam 84 before the move and then reattached after the move. In this embodiment, the count value n of the counter described above is incremented by one each time the sensor device 18 is attached to the target object (slide beam 84). Therefore, a work manager or the like can check, as necessary, whether the sensor device 18 was attached or detached according to the procedure by checking the count value n of the counter. The explanations of the second embodiment regarding the method for fixing the sensor device 18, the method for issuing an alarm, and the setting of the initial tilt angle can also be applied to this modified example.

[0134] The management system 1010 of the second embodiment can be applied not only to crane trucks but also to other vehicle-mounted construction machines equipped with a crane function. The management system 1010 of the second embodiment can also be applied to vehicle-mounted construction machines that do not have a crane function, as long as there is a possibility of them tipping over. The object to which the sensor device 18 is attached is not limited to a part of the outrigger device 82 described above (such as the slide beam 84).

[0135] In the second embodiment in which the object is the transported object (suspended load) 60, the number of attachments does not need to be confirmed, and therefore step S1002 may be omitted. In the second embodiment and the modified example, the server 12 and the alarm device 50 are connected via the network 13, but the alarm device 50 may be connected to the server 12 without going through a network.

[0136] Furthermore, in the second embodiment and the modified example described above, when the server 12 instructs the alarm device 50 to issue an alert, it may also send information (or a signal) to a terminal device connected to the network 13, such as a mobile terminal 16, to notify the occurrence of an emergency.

[0137] Alternatively, a management system configuration in which the server 12 is removed from the configuration shown in FIG. 9 may be adopted. In this case, similar to the server 12 in the second embodiment, the arithmetic processing unit 182 of the sensor device 18 sets the initial inclination angle to the inclination angle measured by the angle sensor 181 when the power supply unit 184 starts supplying power to the angle sensor 181, monitors the change over time in the difference between the initial inclination angle measured by the angle sensor 181 after the setting, and issues an alarm command to the alarm device 50 when the difference exceeds a predetermined threshold. This can be achieved by modifying the software (program) of the arithmetic processing unit 182. In this case, when the arithmetic processing unit 182 instructs the alarm device 50 to issue an alarm, it may also send information notifying the occurrence of an emergency to a terminal device connected to the network 13, such as a mobile terminal 16. In this case, by installing a SIM card in the sensor device 18, information can be transmitted to the terminal via LTE (Long Term Evolution) communication.

[0138] However, it is also possible to provide only the sensor device 18 and the alarm device 50 connected thereto without providing the mobile terminal 16. In other words, the network 13 does not have to be provided.

[0139] In the second embodiment, a plurality of sensor devices 18 and / or alarm devices 50 may be connected to the network 13. A siren may be provided instead of or in addition to the alarm device 50.

[0140] In the second embodiment, a sling-type transported object (suspended load) is taken as an example of an object whose tilt angle is measured by the sensor device 18, but the transported object that is the target in the second embodiment is not limited to a sling-type object, and may be a structure transported by a crane installed at a building construction site, a container suspended and transported by a crane installed at a container port, a structure (bridge girder, etc.) sent out in the construction of a bridge / elevated structure, or a roof (unit) in the construction of a roof to be installed at a stadium. In short, any heavy object that is moved can be a target.

[0141] In the above-described modified example, a crane truck, which is a vehicle-mounted construction machine, was used as the object for measuring the tilt angle by the sensor device 18, but the object is not limited to this, and can also be a crane used in building construction, a crane for transporting containers installed at a container port, etc. In other words, it can also be a machine that moves and transports heavy objects, a mechanism that moves part of a structure to be built, etc.

[0142] In the second embodiment and its modified example, the object whose tilt angle is measured by the sensor device 18 is an object that can be transported or moved by a drive unit. However, the present invention is not limited to this. The sensor device 18 and management system 1010 of the second embodiment may also measure an object fixed to the ground, such as an earth retaining wall or a bearing wall. The issuance of an alarm increases the probability of preventing an accident caused by the collapse of the earth retaining wall or bearing wall. In this case, however, it is not necessary to count the number of times the sensor device 18 is installed, and it is preferable to configure the management system 1010 so that multiple sensor devices 18 measure multiple locations on the object.

[0143] In addition, when monitoring changes over time in the inclination angle of an earth retaining wall or a shear wall over a long period of time, it is necessary to supply power (power feeding) to the sensor device 18. Possible countermeasures in this case include power feeding using a MEMS vibration generator, wireless power feeding (contactless power feeding) that transmits power using an induced magnetic flux generated between an electromagnetic induction type power transmitting side and a power receiving side, solar power generation, or wired LAN power feeding using a LAN cable. In addition, in the second embodiment, depending on the type of object whose inclination angle is measured by the sensor device 18, the management system may be configured to connect the sensor device to the network 13 via a relay device and a base station, as in the first embodiment described above.

[0144] 10...Management system, 12...Server, 18...Sensor device, 40...Relay device, 100...Jet fan (object), 101...Casing, 110...Tunnel (road structure), 110a...Tunnel ceiling, 181...Angle sensor, 200...Suspension system

Claims

1. A method for managing changes in the angle of an object held on a structure, comprising the steps of: performing angle detection of the object for a predetermined period of time using a sensor attached to the object, and acquiring sensor data including a detection value of the angle and a detection time outputted from the sensor; extracting maintenance-related information by subjecting the acquired sensor data to frequency analysis; Management methods including.

2. The management method according to claim 1, The maintenance-related information includes frequency spectrum waveform data obtained from the frequency analysis result.

3. The management method according to claim 1, The management method further includes determining whether or not maintenance is required based on the maintenance-related information.

4. The management method according to claim 3, The method further includes determining in advance a specific frequency component caused by vibration acting on or generated in the object, the frequency component being unaffected by a change over time in the holding state by the structure; The determination is based on whether or not a frequency spectrum of a significant magnitude other than the frequency spectrum of the inherent frequency component is present in the frequency spectrum waveform data.

5. The management method according to claim 4, A management method in which the structure is a tunnel and the target object is a jet fan suspended from the ceiling of the tunnel by a hanging member.

6. The management method according to claim 5, The inherent frequency components are frequency components of vibrations caused by vehicle travel and frequency components of driving vibrations of a jet fan.

7. 2. The management method according to claim 1, The acquisition of the sensor data is performed by a management device via wireless communication between the management device and the sensor.

8. The management method according to claim 7, The acquisition of the sensor data is performed by the management device through wireless communication between the management device and the sensor via a relay device.

9. 2. The management method according to claim 1, The acquiring and extracting are performed in a sensor module including the sensor.

10. 2. The management method according to claim 1, A management method in which the object is held in a suspended state on the structure.

11. The management method according to claim 10, The structure is a road structure.

12. A method for managing changes in the angle of an object, comprising the steps of: monitoring a difference between an initial value and a tilt angle of the object in a predetermined direction measured by a sensor attached to the object; A management method that issues an alarm when the difference exceeds a predetermined threshold.

13. The management method according to claim 12, A management method in which the specified direction includes at least one of the tilt directions about each of two axes perpendicular to each other in a plane perpendicular to the direction of gravity.

14. The management method according to claim 12, The management method, wherein issuing an alarm includes at least one of issuing a loud sound, issuing a siren sound, and issuing a voice message to call attention.

15. The management method according to claim 12, A management method in which, when the sensor is attached to the object, the sensor measures an inclination angle of the object in a predetermined direction, and the measured inclination angle is set as the initial value.

16. The management method according to claim 12, A management method in which the object is an object that can be transported or moved.

17. 17. The management method according to claim 16, A management method in which the object is a load lifted by a crane.

18. 17. The management method according to claim 16, The management method according to the present invention, wherein the object is a construction machine.

19. A management system for managing changes in the angle of an object held on a structure, comprising: a sensor device attached to the object and detecting an angle of the object; a management device that detects the angle by the sensor device for a predetermined period of time and acquires sensor data including a detection value of the angle and a detection time output from the sensor device, The management device is a management system that performs frequency analysis on the acquired sensor data to extract maintenance-related information.

20. 20. The management system according to claim 19, A management system in which the maintenance-related information includes frequency spectrum waveform data obtained from the frequency analysis result.

21. 20. The management system according to claim 19, The management device is a management system that determines whether or not maintenance is required based on the maintenance-related information.

22. 22. The management system according to claim 21, A characteristic frequency component caused by vibration acting on or generated in the object, which is not affected by a change over time in the holding state by the structure, is obtained in advance; The management device is a management system that determines whether or not maintenance is required based on whether or not a frequency spectrum of a significant magnitude other than the frequency spectrum of the unique frequency component is present in the frequency spectrum waveform data.

23. 23. The management system according to claim 22, A management system in which the structure is a tunnel and the object is a jet fan suspended from the ceiling of the tunnel by a hanging member.

24. 24. The management system according to claim 23, A management system in which the inherent frequency components are frequency components of vibrations caused by vehicle travel and frequency components of driving vibrations of a jet fan.

25. 20. The management system according to claim 19, A management system in which the management device acquires the sensor data via wireless communication with the sensor devices.

26. 26. The management system according to claim 25, The management system further comprises a relay device that relays wireless communication between the sensor device and the management device, wherein the sensor data output from the sensor device is transmitted to the management device via the relay device.

27. 27. The management system according to claim 26, The relay device is a management system that relays different types of wireless communications between the sensor device and the management device.

28. 28. The management system according to claim 27, The relay device communicates with the sensor device by LPWA wireless, and performs mobile communication with the management device via a base station and a wide area network.

29. 20. The management system according to claim 19, A management system in which the object is held in a suspended state on the structure.

30. 30. The management system according to claim 29, A management system in which the structure is a road structure.

31. A sensor device used to measure an inclination angle of an object, The present invention includes a sensor unit including an angle sensor for measuring an inclination angle of an object in a predetermined direction and a power supply unit, and a housing that houses the sensor unit therein. A power switch is attached to the housing in a state where it is partially exposed to the outside, The power switch switches from an off state to an on state when the housing is attached to the object, and power supply from the power supply unit to the angle sensor begins.

32. 32. The sensor device according to claim 31, The sensor unit further includes a calculation processing unit, The calculation processing unit sets the inclination angle measured by the angle sensor when power supply from the power supply unit to the angle sensor starts to an initial value of the inclination angle, and calculates the difference between the measurement value of the inclination angle measured by the angle sensor after the setting and the initial value.

33. A management system for managing changes in the angle of an object, A sensor device according to claim 31 attached to the object; an alarm device connected to the sensor device, The sensor unit of the sensor device further includes a calculation processing unit, The calculation processing unit sets the inclination angle measured by the angle sensor when power supply from the power supply unit to the angle sensor starts to an initial value of the inclination angle, calculates the difference between the measurement value of the inclination angle measured by the angle sensor after setting and the initial value, and gives an alarm command to the alarm device when the difference exceeds a predetermined threshold.

34. A management system for managing changes in the angle of an object, A system including the sensor device and the management device according to claim 31, which are connected to each other via a network, and an alarm device connected to the management device, the sensor device transmits a measurement standby command to the management device at a timing when the power switch is switched to an on state; The management device receives the measurement standby command, and after instructing the sensor device to start measurement, starts acquiring angle data measured by the sensor device, sets the angle data acquired at the start of acquisition to an initial value of the inclination angle, and after setting, monitors the change over time in the difference between the angle data measured by the sensor device and the initial value, and when the difference exceeds a predetermined threshold, gives an instruction to the alarm device.

35. 34. The management system according to claim 33, A management system in which the object is an object that can be transported or moved.

36. 36. The management system according to claim 35, A management system in which the object is a load that is lifted by a crane during a rigging operation.

37. 36. The management system according to claim 35, The object is a vehicle-mounted construction machine, The sensor device is configured to be detachably attached to the object, The management device receives the measurement standby command from the sensor device every time the sensor device is attached to the object, and counts the number of times the measurement standby command is received.

38. A management system for managing changes in the angle of an object, a sensor device attached to the object and detecting an angle of the object; A management device connected to the sensor device; an alarm device connected to the management device, The management device monitors the difference between the initial value of the inclination angle of the object in a specified direction measured by the sensor device, and gives an alarm command to the alarm device when the difference exceeds a predetermined threshold.

39. 39. The management system according to claim 38, A management system in which the object is an object that can be transported or moved.

40. 40. The management system according to claim 39, A management system in which the object is a load that is lifted by a crane during a rigging operation.

41. 39. The management system according to claim 38, The management system wherein the object is a construction machine.

42. A method for managing an object held by a structure or moved by a drive unit, comprising the steps of: Detecting an angle of the object using a sensor attached to the object, and acquiring sensor data including detection information of the sensor and a detection time thereof; monitoring the sensor data having different detection times and detecting a state of the object.

43. 43. The method of claim 42, further comprising: A management method in which, when a difference between detection information contained in the sensor data having different detection times exceeds a predetermined value, alarm information is issued.

44. 43. The method of claim 42, further comprising: A management method for detecting a state of the object by performing frequency analysis on the sensor data.

45. A management system for managing an object held by a structure or moved by a drive unit, a sensor device attached to the object and detecting angle information of the object; a management device to which the sensor device is connected via a communication network; the sensor data including the detection information of the sensor device and the detection time thereof is transmitted to the management device via the communication network; The management device is a management system that monitors the sensor data having different detection times and detects the state of the object.

46. 46. ​​The management system according to claim 45, The management device is a management system that activates an alarm device connected to the communication network when a difference between detection information included in the sensor data having different detection times exceeds a predetermined value.