阅读说明：本技术 传感器系统和传感器的落下判定方法 (Sensor system and method for determining falling of sensor ) 是由 武田和义 于 2020-01-31 设计创作，主要内容包括：提供一种传感器系统和传感器的落下判定方法。传感器系统包括：传感器,设置于构造物,检测加速度；存储部,存储设置信息,所述设置信息表示重力加速度的方向与所述传感器的检测轴方向的关系；以及落下判定部,基于所述传感器检测出的所述检测轴方向的加速度的代表值和基于所述设置信息确定的所述检测轴方向的重力加速度值,进行所述传感器是否落下的判定。(Provided are a sensor system and a method for determining falling of a sensor. The sensor system includes: a sensor provided in a structure and detecting acceleration; a storage unit that stores setting information indicating a relationship between a direction of gravitational acceleration and a detection axis direction of the sensor; and a drop determination unit configured to determine whether or not the sensor has dropped based on a representative value of the acceleration in the detection axis direction detected by the sensor and a gravitational acceleration value in the detection axis direction determined based on the setting information.)

1. A sensor system, comprising:

a sensor provided in a structure and detecting acceleration;

a storage unit that stores setting information indicating a relationship between a direction of gravitational acceleration and a detection axis direction of the sensor; and

and a drop determination unit configured to determine whether or not the sensor has dropped based on a representative value of the acceleration in the detection axis direction detected by the sensor and a gravitational acceleration value in the detection axis direction specified based on the setting information.

2. The sensor system of claim 1,

the fall determination unit determines that the sensor has fallen when an absolute value of a difference between a representative value of acceleration detected by the sensor and the gravitational acceleration value is greater than a determination value with respect to the detection axis direction.

3. The sensor system of claim 2,

the sensor has a plurality of the detection axes in mutually different directions,

the fall determination unit determines that the sensor falls when an absolute value of the difference is larger than a determination value for any one or more of the plurality of detection axis directions.

4. The sensor system of claim 1,

the sensor has a plurality of the detection axes in mutually different directions,

the fall determination unit determines that the sensor falls when an absolute value of a difference between a representative value of the acceleration detected by the sensor and the gravitational acceleration value is greater than a first determination value for any two or more of the plurality of detection axis directions.

5. The sensor system of claim 1,

the sensor has a plurality of the detection axes in mutually different directions,

the fall determination unit determines that the sensor has fallen when a difference between an absolute value of the representative value of the acceleration detected by the sensor and an absolute value of the gravitational acceleration value is greater than a first determination value for any two or more of the plurality of detection axis directions.

6. The sensor system according to claim 4 or 5,

the fall determination unit determines that the sensor falls when an absolute value of the difference is larger than a second determination value for any one or more of the plurality of detection axis directions.

7. The sensor system of claim 1,

the representative value is a mean or median value.

8. The sensor system of claim 1,

the storage unit stores the determination result of the drop determination unit,

the fall determination unit does not perform the determination when the determination result stored in the storage unit indicates that the sensor falls.

9. The sensor system of claim 1,

the sensor system includes an arithmetic unit for performing an arithmetic operation based on an acceleration value detected by the sensor,

the fall determination unit does not output the acceleration value detected by the sensor to the calculation unit when it is determined that the sensor has fallen.

10. The sensor system of claim 1,

the sensor system includes an output unit that outputs a determination result of the drop determination unit to the outside of the sensor system.

11. A method for determining falling of a sensor, comprising:

a data acquisition step of acquiring an output signal of a sensor that is provided in a structure and detects acceleration;

a representative value calculation step of calculating a representative value of the acceleration in the detection axis direction detected by the sensor based on the output signal of the sensor; and

and a drop determination step of determining whether or not the sensor has dropped based on the representative value of the acceleration in the detection axis direction and a gravitational acceleration value in the detection axis direction determined based on setting information indicating a relationship between the direction of the gravitational acceleration stored in the storage unit and the detection axis direction of the sensor.

Technical Field

The invention relates to a sensor system and a method for determining falling of a sensor.

Background

Patent document 1 describes a drop detection device that detects accelerations in directions along three axes orthogonal to each other, obtains a determination value that is a difference between an acceleration value in the direction along the other two axes and a detection value in the direction along one axis as a reference, and determines that a state is dropping when a state in which the determination value is within a predetermined value range continues for a predetermined time or longer.

Patent document 1: international publication No. 2010/010781

However, the drop detection device described in patent document 1 detects a falling state by the acceleration becoming 0G during the falling, and has the following problems: if the state during the fall cannot be detected, it cannot be determined as a fall after the fall.

Disclosure of Invention

One aspect of the sensor system of the present invention is characterized by comprising: a sensor provided in a structure and detecting acceleration; a storage unit that stores setting information showing a relationship between a direction of gravitational acceleration and a detection axis direction of the sensor; and a drop determination unit configured to determine whether or not the sensor has dropped based on a representative value of the acceleration in the detection axis direction detected by the sensor and a gravitational acceleration value in the detection axis direction determined based on the setting information.

In one aspect of the sensor system, the fall determination unit may determine that the sensor falls when an absolute value of a difference between a representative value of the acceleration detected by the sensor and the gravitational acceleration value is larger than a determination value with respect to the detection axis direction.

In one aspect of the sensor system, the sensor may have a plurality of the detection axes in different directions, and the fall determination unit may determine that the sensor falls when an absolute value of the difference is larger than a determination value for at least one of the plurality of detection axis directions.

In one aspect of the sensor system, the sensor may have a plurality of the detection axes in directions different from each other, and the fall determination unit may determine that the sensor falls when an absolute value of a difference between a representative value of the acceleration detected by the sensor and the gravitational acceleration value is larger than a first determination value for any two or more of the plurality of detection axes.

In one aspect of the sensor system, the sensor may have a plurality of the detection axes in directions different from each other, and the fall determination unit may determine that the sensor falls when a difference between an absolute value of a representative value of the acceleration detected by the sensor and an absolute value of the gravitational acceleration value is larger than a first determination value for any two or more of the plurality of detection axes.

In one aspect of the sensor system, the fall determination unit may determine that the sensor falls when an absolute value of the difference is larger than a second determination value with respect to any one or more of the plurality of detection axis directions.

In one form of the sensor system, the representative value may be a mean value or a median value.

In one aspect of the sensor system, the storage unit may store a determination result of the drop determination unit, and the drop determination unit may not perform the determination when the determination result stored in the storage unit indicates that the sensor has dropped.

In one aspect of the sensor system, the sensor system may include an arithmetic unit that performs arithmetic operation based on an acceleration value detected by the sensor, and the fall determination unit may not output the acceleration value detected by the sensor to the arithmetic unit when it is determined that the sensor has fallen.

In one aspect of the sensor system, the sensor system may include an output unit that outputs a determination result of the drop determination unit to an outside of the sensor system.

One aspect of the sensor drop determination method according to the present invention is a sensor drop determination method including: a data acquisition step of acquiring an output signal of a sensor that is provided in a structure and detects acceleration; a representative value calculation step of calculating a representative value of the acceleration in the detection axis direction detected by the sensor based on the output signal of the sensor; and a drop determination step of determining whether or not the sensor has dropped based on the representative value of the acceleration in the detection axis direction and a gravitational acceleration value in the detection axis direction determined based on setting information indicating a relationship between the direction of the gravitational acceleration stored in the storage unit and the detection axis direction of the sensor.

Drawings

Fig. 1 is a diagram showing a structure monitoring system according to a first embodiment.

Fig. 2 is a diagram showing an example of a state in which a plurality of sensors are mounted in a building.

Fig. 3 is a diagram showing a configuration example of the measurement device in the first embodiment.

Fig. 4 is a diagram illustrating an example of a state in which the sensor is attached to a structure.

Fig. 5 is a diagram showing another example of a state in which the sensor is attached to a structure.

Fig. 6 is a diagram showing a state after the sensor in fig. 4 is dropped.

Fig. 7 is a diagram showing a state after the sensor in fig. 5 is dropped.

Fig. 8 is a flowchart showing an example of processing steps performed by the processing unit executing the measurement program in the first embodiment.

Fig. 9 is a flowchart showing an example of the procedure of the drop determination processing in the first embodiment.

Fig. 10 is a diagram showing a structure of a structure monitoring system according to a second embodiment.

Fig. 11 is a diagram showing an example of the configuration of the sensor system in the second embodiment.

Fig. 12 is a diagram showing a configuration example of the measuring apparatus according to the second embodiment.

Fig. 13 is a flowchart showing an example of processing steps performed by the processing unit executing the measurement program in the second embodiment.

Fig. 14 is a flowchart showing an example of the procedure of the drop determination processing in the second embodiment.

Fig. 15 is a flowchart showing an example of the procedure of the drop determination processing in the modification.

Description of the reference numerals

1. 1a … sensor system, 2 … building, 4 … steel skeleton column, 5a, 5b, 5c … cable, 6 … T connector, 7 … magnet holder, 10 … sensor, 10a … sensor body, 10b … connector, 20, 20a … measuring device, 21 … processing section, 22 … storage section, 23 … communication section, 30 … communication network, 40 … management system, 51 … processing section, 52 … storage section, 53 … communication section, 61 … processing section, 62 … storage section, 63 … communication section, 100, 100a … structure monitoring system, 211 … data acquisition section, 212 … drop determination section, 213 … calculation section, 214 … communication control section, 215 … management section, 221 … setting information, 222 … measuring program, 223 … calculation program, 224 … communication program, 225 … management program, 226 drop determination section 226 …, 39511 drop determination section 511 … acquisition section, 512 … drop determination section, 514 … communication control section, 515 … management section, 521 … setting information, 522 … measurement program, 524 … communication program, 525 … management program, 526 … drop determination result information, 611 … data acquisition section, 613 … arithmetic section, 614 … communication control section, 615 … management section, 623 … arithmetic program, 624 … communication program, 625 … management program.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are not intended to limit the contents of the present invention described in the claims. All the configurations described below are not necessarily essential components of the present invention.

The sensor system of the present invention can be used for various systems. Hereinafter, a structure monitoring system using the sensor system of the present invention will be described as an example.

1. First embodiment

1-1. Structure monitoring System configuration

Fig. 1 is a diagram showing a structure monitoring system according to a first embodiment. As shown in fig. 1, the structure monitoring system 100 includes a sensor system 1 and a management system 40. The sensor system 1 includes n sensors 10 and a measurement device 20. Wherein n is an integer of 1 or more.

Each of the n sensors 10 is an acceleration sensor, is provided on the structure, has a plurality of detection axes in different directions, and detects acceleration in the direction of the plurality of detection axes, and may be, for example, a quartz acceleration sensor or an MEMS (Micro Electro Mechanical Systems) acceleration sensor. In the present embodiment, each of the n sensors 10 has three detection axes of X, Y, and Z axes orthogonal to each other, and detects acceleration in the X, Y, and Z axes directions.

The structure provided with the n sensors 10 may be a stationary structure, that is, a structure that does not move relative to the ground surface. Fig. 2 is a diagram showing an example of a state in which n sensors 10 are mounted on a building 2 as a structure. In the example of fig. 2, the building 2 is a five-story building having floors 1F to 5F, a roof RF, and a steel column 4, and five sensors 10 are mounted on the building 2. Specifically, the four sensors 10 are attached to the steel skeleton column 4 at four positions, i.e., between the floor 1F and the floor 2F, between the floor 3F and the floor 4F, between the floor 5F and the roof RF, and at four positions of the roof RF. Further, one sensor 10 is mounted on the floor 1F. Thus, in the example of fig. 2, five sensors 10 are provided at mutually different height positions of the building 2. However, the arrangement and number of the sensors 10 are not particularly limited, and may be appropriately changed according to the size, shape, and the like of the structure.

Returning to fig. 1, each of the n sensors 10 and the measurement device 20 are connected by a communication bus (not shown), for example, a CAN (Controller Area Network), and the measurement device 20 communicates with the n sensors 10 via the communication bus. CAN is a communication system having high reliability against errors and noises, and is suitable for this embodiment. However, the communication between each of the n sensors 10 and the measuring device 20 is not limited to CAN, and may be connected by another communication bus specification or LAN (Local Area Network). The communication between each sensor 10 and the measuring device 20 may be wired communication or wireless communication. The measurement device 20 communicates with the management system 40 via the communication network 30. The communication network 30 may be a public line such as the internet.

Each of the n sensors 10 measures acceleration caused by vibration of the structure, and transmits measured acceleration data to the measurement device 20. The measurement device 20 receives acceleration data from each of the n sensors 10, generates information relating to the state of the structure based on the acceleration data, and transmits the information to the management system 40. The information related to the state of the structure may include information such as displacement and fatigue of the structure.

The measurement device 20 is installed inside the structure or outside the structure and in proximity to the structure. Further, the management system 40 is provided at a remote location from the structure. A monitor can monitor the state of the structure from a remote location via the management system 40. However, the installation locations of the measurement device 20 and the management system 40 are not particularly limited.

1-2. construction of measuring device

Fig. 3 is a diagram showing an example of the configuration of the measuring device 20. As shown in fig. 3, the measurement device 20 includes: a processing unit 21, a storage unit 22, and a communication unit 23.

The storage unit 22 stores setting information 221. The setting information 221 is information as follows: the relationship between the direction of the gravitational acceleration and the direction of each detection axis of each sensor 10 is shown in a state where each sensor 10 is attached to a structure. For example, in a state where the sensor 10 is attached to a structure so that the Y-axis direction is vertically upward, the gravitational acceleration value in the Y-axis direction is-1G, and the gravitational acceleration value in the X-axis direction and the gravitational acceleration value in the Z-axis direction are 0G. Therefore, the setting information 221 may include information indicating that the acceleration values of gravity in the X-axis direction, the Y-axis direction, and the Z-axis direction of the sensor 10 are 0G, -1G, and 0G, respectively.

The storage unit 22 also stores a measurement program 222, an arithmetic program 223, a communication program 224, and a management program 225.

The storage unit 22 may include a semiconductor Memory such as an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory), or a volatile Memory such as a register. The storage unit 22 may include a semiconductor Memory such as an EEPROM (Electrically erasable programmable Read Only Memory) or a flash Memory, a magnetic storage device such as a hard disk device, or a nonvolatile Memory such as an optical storage device such as an optical disk device.

The communication unit 23 is an interface unit for communicating the measurement device 20 with the management system 40. In the present embodiment, the processing unit 21 transmits various information obtained by the calculation of the calculation unit 213 to the management system 40 via the communication unit 23. The management system 40 also transmits the latest version of each program to the storage unit 22 via the communication unit 23.

The processing unit 21 includes: a data acquisition unit 211, a drop determination unit 212, a calculation unit 213, a communication control unit 214, and a management unit 215.

In the present embodiment, the Processing Unit 21 is a Processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a DSP (Digital Signal Processor), and functions as each of the above-described units by executing various programs stored in the storage Unit 22 as an information storage device. Specifically, the processing unit 21 functions as the data acquisition unit 211 and the drop determination unit 212 by executing the measurement program 222. The processing unit 21 functions as the arithmetic unit 213 by executing the arithmetic program 223. The processing unit 21 functions as the communication control unit 214 by executing the communication program 224. The processing unit 21 functions as a management unit 215 by executing the management program 225.

The data acquisition unit 211 acquires acceleration data which is output signals of the n sensors 10.

The drop determination unit 212 determines whether or not each sensor 10 has dropped based on the representative value of the acceleration in each detection axis direction detected by each sensor 10 and the gravitational acceleration value in each detection axis direction of each sensor 10 specified based on the setting information 221. In the present embodiment, the drop determination unit 212 determines whether each of the n sensors 10 has dropped at a predetermined cycle, and stores the determination result in the storage unit 22 as drop determination result information 226. The details of the processing of drop determination unit 212 will be described later.

The calculation unit 213 performs calculation based on the acceleration values detected by the sensors 10. The calculation unit 213 performs calculation for calculating displacement, fatigue, and the like of the structure, for example.

The communication control unit 214 controls the communication operation between the communication unit 23 and the management system 40.

The management unit 215 monitors whether or not the data acquisition unit 211, the drop determination unit 212, the calculation unit 213, and the communication control unit 214 are operating normally. When any one of the data acquisition unit 211, the drop determination unit 212, the calculation unit 213, and the communication control unit 214 is abnormal, the management unit 215 terminates the corresponding program and restarts the program. The management unit 215 monitors whether or not the latest version of each of the measurement program 222, the calculation program 223, and the communication program 224 is stored in the storage unit 22. When the latest version of any program is stored in the storage unit 22, the management unit 215 terminates the corresponding program, updates the program to the latest version, and restarts the program.

1-3. method for determining falling of sensor

Fig. 4 is a diagram illustrating an example of a state in which the sensor 10 is attached to a structure. Fig. 5 is a diagram showing another example of a state in which the sensor 10 is attached to a structure.

In fig. 4 and 5, the cables 5a, 5b, 5c and the T-shaped connector 6 form part of a communication bus. One end of each of the cables 5a, 5b, 5c is connected to a T-connector 6. The other end of the cable 5c is connected to the connector 10b of the sensor 10. Although not shown, the other ends of the cables 5a and 5b are connected to other T-connectors. The T-shaped connector, not shown, is connected to the connector 10b of another sensor 10 or the connector of the measurement device 20, not shown. The sensor body 10a of the sensor 10 is fixed to the magnet holder 7 by a screw or the like, and the magnet holder 7 is attached to a metal part of a structure by a magnetic force.

In the example of fig. 4, the T-shaped connector 6 is attached to the structure so that the cables 5a and 5b are substantially perpendicular to each other, and the magnet holder 7 is attached to the structure so that the X-axis direction of the sensor 10 is opposite to the gravitational acceleration direction. Therefore, the gravitational acceleration value in the X-axis direction is-1G, and the gravitational acceleration value in the Y-axis direction and the gravitational acceleration value in the Z-axis direction are 0G.

Therefore, the setting information 221 includes information indicating that the acceleration values of gravity in the X-axis direction, the Y-axis direction, and the Z-axis direction of the sensor 10 are-1G, 0G, and 0G, respectively, for example.

In the example of fig. 4, when the magnet holder 7 is detached from the structure for some reason, the sensor 10 falls to the state shown in fig. 6, and the orientation is changed by 90 ° from the installation orientation. That is, in the example of fig. 4, when the sensor 10 is dropped, the Y-axis direction of the sensor 10 and the gravitational acceleration direction are oriented in the same direction. Therefore, the gravitational acceleration value in the X-axis direction is 0G, the gravitational acceleration value in the Y-axis direction is 1G, and the gravitational acceleration value in the Z-axis direction is kept at 0G. Therefore, in the case where the sensor 10 falls from the state of fig. 4, the difference in the gravitational acceleration values in the X-axis direction is 1G, the difference in the gravitational acceleration values in the Y-axis direction is 1G, and the difference in the gravitational acceleration values in the Z-axis direction is 0G. Further, if the sensor 10 is dropped from the state where the magnet clamp 7 is attached to the structure so that the X-axis direction of the sensor 10 and the gravitational acceleration direction are in the same direction, the difference in the gravitational acceleration values in the X-axis direction is-1G, the difference in the gravitational acceleration values in the Y-axis direction is 1G, and the difference in the gravitational acceleration values in the Z-axis direction is 0G. Depending on the orientation in which the sensor 10 is fixed to the magnet holder 7 or the orientation in which the magnet holder 7 is attached to the structure, the difference in the gravitational acceleration values in the X-axis direction, the difference in the gravitational acceleration values in the Y-axis direction, and the difference in the gravitational acceleration values in the Z-axis direction can be 1G or-1G. That is, when the sensor 10 is dropped and the orientation is changed by 90 ° from the installation orientation, the absolute value of the difference between the gravitational acceleration value after the sensor 10 is dropped and the gravitational acceleration value when the sensor 10 is installed is 1G in the directions of any two axes of the X axis, the Y axis, and the Z axis, and the difference is 0G in the direction of the other axis.

Therefore, the drop determination unit 212 calculates the absolute value of the difference between the gravitational acceleration value calculated from the acceleration data output from the sensor 10 and the gravitational acceleration value when the sensor 10 is installed for each of the X-axis direction, the Y-axis direction, and the Z-axis direction, and can determine that the sensor 10 has dropped if the absolute value of the difference between the gravitational acceleration values in any two or more axial directions is greater than the first determination value.

Here, since the structure vibrates periodically, the sensor 10 detects acceleration due to the vibration of the structure together with the gravitational acceleration. Therefore, the acceleration values in the X-axis direction, the Y-axis direction, and the Z-axis direction detected by the sensor 10 do not coincide with the acceleration values in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. Therefore, in order to reduce the acceleration value based on the periodic vibration of the structure, the fall determination unit 212 calculates representative values of the acceleration values in the X-axis direction, the Y-axis direction, and the Z-axis direction detected by the sensor 10. Then, the drop determination unit 212 determines that the sensor 10 has dropped when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravitational acceleration value specified based on the setting information 221 is greater than the first determination value in any two or more of the X-axis direction, the Y-axis direction, and the Z-axis direction. The first determination value is set to 500mG, which is half 1G, for example.

Further, if the calculation time of the representative value of the acceleration detected by the sensor 10 is extended, the acceleration value based on the periodic vibration of the structure is further reduced, so that the first determination value can be further reduced, and the drop determination unit 212 can determine that the sensor 10 has dropped even when the sensor 10 has dropped and the orientation has changed by 30 °, 45 °, or 60 ° from the installation orientation. However, if the calculation time of the representative value of the acceleration is too long, the calculation load becomes large, and the calculation accuracy of the representative value may be degraded due to the influence of the temperature change of the sensor 10, and therefore, it is preferable to appropriately set the calculation time of the representative value of the acceleration in consideration of the falling mode of the sensor 10 and the like.

On the other hand, in the example of fig. 5, the T-shaped connector 6 is attached to the structure so that the cables 5a and 5b are almost horizontal, and the magnet holder 7 is attached to the structure so that the Y-axis direction of the sensor 10 is opposite to the gravitational acceleration direction. Therefore, the gravitational acceleration value in the Y-axis direction is-1G, and the gravitational acceleration value in the X-axis direction and the gravitational acceleration value in the Z-axis direction are 0G. Therefore, the setting information 221 includes, for example, information indicating that the acceleration values of the sensor 10 in the X-axis direction, the Y-axis direction, and the Z-axis direction are 0G, -1G, and 0G, respectively.

In the example of fig. 5, when the magnet holder 7 is detached from the structure for some reason, the sensor 10 falls to the state shown in fig. 7, and the orientation is changed by 180 ° from the installation orientation. That is, in the example of fig. 5, when the sensor 10 is dropped, the Y-axis direction of the sensor 10 and the gravitational acceleration direction are in the same direction. Therefore, the gravitational acceleration value in the Y-axis direction is 1G, and the gravitational acceleration value in the X-axis direction and the gravitational acceleration value in the Z-axis direction are kept to 0G. Therefore, when the sensor 10 falls from the state of fig. 5, the difference in the gravitational acceleration values in the Y-axis direction is 2G, and the difference in the gravitational acceleration values in the X-axis direction and the Z-axis direction is 0G. Further, if the sensor 10 is dropped from the state where the magnet holder 7 is attached to the structure so that the Y-axis direction of the sensor 10 is oriented in the same direction as the gravitational acceleration direction, the difference between the gravitational acceleration values in the Y-axis direction is-2G, and the difference between the gravitational acceleration values in the X-axis direction and the Z-axis direction is 0G. Depending on the orientation in which the sensor 10 is fixed to the magnet holder 7 or the orientation in which the magnet holder 7 is attached to the structure, the difference in the gravitational acceleration values in the X-axis direction, the difference in the gravitational acceleration values in the Y-axis direction, and the difference in the gravitational acceleration values in the Z-axis direction can be 2G or-2G. That is, when the sensor 10 is dropped and the orientation is changed by 180 ° from the installation orientation, the absolute value of the difference between the gravitational acceleration value after the sensor 10 is dropped and the gravitational acceleration value when the sensor 10 is installed is 2G in the direction of any one of the X axis, the Y axis, and the Z axis, and the difference is 0G in the directions of the other two axes. Therefore, when the sensor 10 falls and the orientation is changed by 180 ° from the installation orientation, it cannot be determined that the sensor 10 falls under the condition that the absolute value of the difference between the gravitational acceleration values in any two or more axial directions is larger than the first determination value.

Therefore, the fall determination unit 212 calculates the absolute value of the difference between the gravitational acceleration value calculated from the acceleration data output from the sensor 10 and the gravitational acceleration value when the sensor 10 is installed, for each of the X-axis direction, the Y-axis direction, and the Z-axis direction, and determines that the sensor 10 falls when the absolute value of the difference between the gravitational acceleration values in any one or more axial directions is larger than the second determination value.

That is, in any one or more of the X-axis direction, the Y-axis direction, and the Z-axis direction, when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravitational acceleration value specified based on the setting information 221 is larger than the second determination value, the drop determination unit 212 determines that the sensor 10 has dropped. The second determination value is set to a value larger than the first determination value, for example, 1G which is half of 2G.

1-4. processing of measurement program

Fig. 8 is a flowchart showing an example of processing steps performed by the processing unit 21 executing the measurement program 222.

As shown in fig. 8, if the processing unit 21 is in a measurable state (Y in step S1), it first functions as the data acquisition unit 211 to acquire acceleration data from each sensor 10 (step S2).

Next, the processing unit 21 functions as the fall determination unit 212, refers to the fall determination result information 226 stored in the storage unit 22 (step S3), and outputs the acceleration data of each sensor 10 that has not fallen to the calculation unit 213 (step S4). Therefore, the calculation unit 213 performs calculation based on the acceleration data output from the drop determination unit 212, that is, the acceleration values detected by the sensors 10 that have not dropped. In other words, when determining that the sensor 10 is falling, the fall determination unit 212 does not output the acceleration value detected by the sensor 10 to the calculation unit 213, and therefore the calculation unit 213 does not use the acceleration value detected by the falling sensor 10 for calculation. Therefore, the risk that the calculation unit 213 performs an erroneous calculation based on the acceleration value detected by the falling sensor 10 is reduced.

Next, the processing unit 21 determines whether or not a predetermined time has elapsed since the state was made measurable or since the drop determination of step S7 was performed last time (step S6), and when the predetermined time has elapsed (Y of step S6), the processing unit functions as the drop determination unit 212 to perform the drop determination of each sensor 10 (step S7). If the predetermined time has not elapsed (N in step S6), the processing unit 21 does not perform the drop determination in step S7.

The processing unit 21 repeats the processing of steps S2 to S7 until the management unit 215 terminates and restarts the measurement program 222 (N of step S8). Further, if the management unit 215 finishes and restarts the measurement program 222 (Y at step S8), the processing unit 21 repeats the processing at steps S2 to S7 after the measurement program is in a measurable state (Y at step S1).

Fig. 9 is a flowchart showing an example of the step of the drop determination processing in step S7 in fig. 8. The processing unit 21 functions as the drop determination unit 212 and performs the processing of steps S101 to S113 in fig. 9.

First, the drop determination unit 212 sets the variable i to 1 (step S101) and refers to the drop determination result information 226 stored in the storage unit 22 (step S102).

Next, when the fall determination result information 226 indicates that the i-th sensor 10 has not fallen (N in step S103), the fall determination unit 212 calculates a representative value of acceleration data for each detection axis of the i-th sensor 10 (step S104).

Next, the drop determination unit 212 refers to the installation information 221 stored in the storage unit 22 (step S105).

Next, the drop determination unit 212 calculates an absolute value of a difference between the representative value of the acceleration data calculated in step S104 and the gravitational acceleration value determined based on the setting information 221 for each detection axis of the i-th sensor 10 (step S106).

When there are not two or more detection axes having a difference calculated in step S106 larger than the first determination value (N in step S107), and when there are not 1 or more detection axes having a difference calculated in step S106 larger than the second determination value (N in step S108), the drop determination unit 212 determines that the i-th sensor 10 has not dropped (step S109).

If there are two or more detection axes having a difference calculated in step S106 larger than the first determination value (Y in step S107), or if there is one or more detection axes having a difference calculated in step S106 larger than the second determination value (Y in step S108), the drop determination unit 212 determines that the i-th sensor 10 has dropped (step S110).

Next, the drop determination unit 212 updates the drop determination result information 226 with the determination result of step S109 or the determination result of step S110 (step S111).

When the fall determination result information 226 indicates that the i-th sensor 10 falls (Y in step S103), the fall determination unit 212 does not perform the processing in steps S104 to S111, that is, the fall determination of the i-th sensor 10.

When the variable i is smaller than the total number N of the sensors 10 (Y in step S112), the drop determination unit 212 increments the variable i by 1 (step S113) and repeats the processing from step S102 and thereafter, and if the variable i is equal to N (N in step S112), the drop determination processing is terminated.

In fig. 8 and 9, the fall determination is performed by calculating the representative value and the absolute value of the acceleration data acquired from each sensor 10 for a predetermined time every time the predetermined time elapses, but the fall determination may be performed by calculating the moving average value and the absolute value thereof or the moving median value and the absolute value thereof for the predetermined time of the acceleration data every time the acceleration data is acquired from each sensor 10.

Step S2 in fig. 8 is an example of the data acquisition step. Step S104 in fig. 9 is an example of a representative value calculation step. Steps S105, S106, S107, S108, S109, and S110 in fig. 9 exemplify a drop determination step.

1-5. Effect

As described above, in the present embodiment, the fall determination unit 212 determines whether or not the sensor 10 has fallen based on the representative value of the acceleration in each of the three axial directions detected by the sensor 10 provided in the structure and the gravitational acceleration value in each of the three axial directions specified by the setting information 221 stored in the storage unit 22. That is, the fall determination unit 212 determines that the sensor 10 falls based on the difference between the orientation of the gravitational acceleration based on the setting information 221 before the sensor 10 falls and the orientation of the gravitational acceleration based on the detection value of the sensor 10 after the sensor 10 falls. Therefore, according to the sensor system 1A of the present embodiment or the sensor drop determination method of the present embodiment, it is not necessary to detect a state in the middle of the drop of the sensor 10, and it is possible to determine that the sensor 10 has dropped even after the sensor 10 has dropped. Therefore, for example, even when the sensor 10 falls during a period from the end of the measurement program 222 to the restart, the fall determination unit 212 can determine that the sensor 10 falls after the restart of the measurement program 222.

In the present embodiment, the drop determination unit 212 determines that the sensor 10 has dropped when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravitational acceleration value is greater than the first determination value in any two or more directions of the three axes. Therefore, according to the sensor system 1A of the present embodiment or the sensor drop determination method of the present embodiment, for example, when the sensor 10 drops and the orientation of the sensor 10 changes in a range including 90 ° to some extent from before the drop, it can be determined that the sensor 10 drops.

In the present embodiment, the drop determination unit 212 determines that the sensor 10 has dropped when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravitational acceleration value is greater than the second determination value in any one or more of the three axial directions. Therefore, according to the sensor system 1A of the present embodiment or the method of determining the falling of the sensor of the present embodiment, for example, when the sensor 10 falls and the orientation of the sensor 10 is changed in a range including 180 ° to some extent from before the fall, it can be determined that the sensor 10 falls.

In the present embodiment, the fall determination unit 212 stores the result of the fall determination in the storage unit 22, and when the determination result stored in the storage unit 22 indicates that the sensor 10 has fallen, the fall determination is not performed thereafter. Therefore, for example, when the measurement program 222 is restarted, the drop determination unit 212 does not need to perform the drop determination when the sensor 10 determines that the sensor has dropped before the restart. Therefore, according to the sensor system 1A of the present embodiment or the sensor drop determination method of the present embodiment, unnecessary power consumption of the sensor system 1 caused by the drop determination in which the determination result is specified can be reduced.

In the present embodiment, when determining that the sensor 10 is falling, the fall determination unit 212 does not output the acceleration value detected by the sensor 10 to the calculation unit 213. Therefore, according to the sensor system 1A of the present embodiment or the sensor drop determination method of the present embodiment, it is possible to reduce the risk that the calculation unit 213 performs an erroneous calculation based on the acceleration value detected by the sensor 10 that has dropped.

2. Second embodiment

Hereinafter, the same components as those of the first embodiment in the second embodiment will be given the same reference numerals, and the description thereof will be mainly given of differences from the first embodiment, and redundant description thereof will be omitted or simplified.

2-1. Structure monitoring System configuration

Fig. 10 is a diagram showing a structure of a structure monitoring system according to a second embodiment. As shown in fig. 10, a structure monitoring system 100A includes: n sensor systems 1A, a measurement device 20A, and a management system 40. Wherein n is an integer of 1 or more.

Each of the n sensor systems 1A is connected to the measurement device 20A via a communication bus, not shown, and the measurement device 20A communicates with the n sensor systems 1A via the communication bus.

The measurement device 20A communicates with the management system 40 via the communication network 30.

Each of the n sensor systems 1A is installed in a structure, measures acceleration caused by vibration of the structure, and transmits measured acceleration data to the measurement device 20A. For example, the n sensor systems 1A are mounted on the building 2 as a structure in the same manner as in the case shown in fig. 2.

The measurement device 20A receives acceleration data from each of the n sensor systems 1A, generates information relating to the state of the structure based on the acceleration data, and transmits the information to the management system 40.

2-2. construction of sensor System

Fig. 11 is a diagram showing a configuration example of the sensor system 1A. As shown in fig. 11, the sensor system 1A includes: a sensor 10, a processing unit 51, a storage unit 52, and a communication unit 53.

The sensor 10 is an acceleration sensor, has a plurality of detection axes in different directions from each other, and detects accelerations in the directions of the plurality of detection axes.

The storage unit 52 stores setting information 521. The setting information 521 is the following information: the relationship between the direction of the gravitational acceleration and the direction of each detection axis of the sensor 10 is shown in a state where the sensor 10 is attached to a structure. The storage unit 52 stores a measurement program 522, a communication program 524, and a management program 525.

The communication unit 53 is an interface unit for communicating the sensor system 1A and the measurement device 20A. In the present embodiment, the processing unit 51 transmits the acceleration data acquired by the data acquisition unit 511 from the sensor 10 or the information of the determination result of the fall determination unit 512 to the measurement device 20A via the communication unit 53. The measurement device 20A transmits the measurement program 522 and the latest version of the communication program 524 to the storage unit 52 via the communication unit 53.

The processing unit 51 includes: a data acquisition unit 511, a drop determination unit 512, a communication control unit 514, and a management unit 515. In the present embodiment, the processing unit 51 is a processor, and functions as the above-described units by executing various programs stored in the storage unit 52 as an information storage device. Specifically, the processing unit 51 functions as the data acquisition unit 511 and the drop determination unit 512 by executing the measurement program 522. The processing unit 51 functions as the communication control unit 514 by executing the communication program 524. The processing unit 51 also functions as a management unit 515 by executing the management program 525.

The data acquisition unit 511 acquires acceleration data as an output signal of the sensor 10. The data acquisition unit 511 transmits the acquired acceleration data to the measurement device 20A via the communication unit 53.

The drop determination unit 512 determines whether or not the sensor 10 has dropped based on the representative value of the acceleration in each detection axis direction detected by the sensor 10 and the gravitational acceleration value in each detection axis direction of the sensor 10 specified based on the setting information 521. The drop determination unit 512 determines whether or not the sensor 10 has dropped at predetermined intervals, and stores the determination result in the storage unit 52 as drop determination result information 526. The drop determination unit 512 transmits the determination result to the measurement device 20A via the communication unit 53. That is, the communication unit 53 functions as an output unit that outputs the determination result of the drop determination unit 512 to the outside of the sensor system 1A.

The communication control unit 514 controls the communication operation between the communication unit 53 and the measurement device 20A.

The management unit 515 monitors whether or not the data acquisition unit 511, the drop determination unit 512, and the communication control unit 514 are operating normally. When any one of the data acquisition unit 511, the drop determination unit 512, and the communication control unit 514 has an abnormal operation, the management unit 515 terminates the corresponding program and restarts the program. The management unit 515 monitors whether or not the latest version of each of the measurement program 522 and the communication program 524 is stored in the storage unit 52. When the latest version of any program is stored in the storage unit 52, the management unit 515 terminates the corresponding program, updates the program to the latest version, and restarts the program.

2-3. construction of measuring device

Fig. 12 is a diagram showing a configuration example of the measurement device 20A. As shown in fig. 12, the measurement device 20A includes: a processing unit 61, a storage unit 62, and a communication unit 63.

The storage unit 62 stores an arithmetic program 623, a communication program 624, and a management program 625.

The communication unit 63 is an interface unit for communicating the measurement device 20A with the management system 40. In the present embodiment, the processing unit 61 transmits various information obtained by the calculation of the calculation unit 613 to the management system 40 via the communication unit 63. The management system 40 also transmits the latest version of each program to the storage unit 62 via the communication unit 63.

The processing section 61 includes: a data acquisition unit 611, a calculation unit 613, a communication control unit 614, and a management unit 615.

In the present embodiment, the processing unit 61 is a processor, and functions as the above-described units by executing various programs stored in the storage unit 62 as an information storage device.

Specifically, the processing unit 61 functions as the data acquisition unit 611 and the arithmetic unit 613 by executing the arithmetic program 623. The processing unit 61 also functions as the communication control unit 614 by executing the communication program 624. The processing unit 61 also functions as the management unit 615 by executing the management program 625.

The data acquisition unit 611 acquires the acceleration data, which is the output signal of the n sensor systems 1A, and the determination result of the drop determination of the sensor 10. The data acquisition unit 611 then outputs the acceleration data from the sensor system 1A determined that the sensor 10 has not fallen to the calculation unit 613. In other words, the data acquisition unit 611 does not output the acceleration data from the sensor system 1A, which has determined that the sensor 10 has fallen, to the calculation unit 613.

The arithmetic unit 613 performs arithmetic operation based on the acceleration data output from the data acquisition unit 611.

The calculation unit 613 performs calculations for calculating the displacement, fatigue, and the like of the structure, for example.

The communication control unit 614 controls the communication operation of the management system 40 by the communication unit 63.

The management unit 615 monitors whether or not the data acquisition unit 611, the calculation unit 613, and the communication control unit 614 operate normally. When any one of the data acquisition unit 611, the arithmetic unit 613, and the communication control unit 614 has an abnormal operation, the management unit 615 terminates the corresponding program and restarts the program. The management unit 615 monitors whether or not the latest version of each of the calculation program 623 and the communication program 624 is stored in the storage unit 62. When the latest version of any program is stored in the storage unit 62, the management unit 615 terminates the corresponding program, updates the program to the latest version, and restarts the program. Further, if the management unit 615 receives the latest version of the measurement program 522 from the management system 40 via the communication unit 63, the latest version of the measurement program 522 is transmitted to each sensor system 1A.

2-4. processing of measurement program

Fig. 13 is a flowchart showing an example of processing steps performed by the processing unit 51 by executing the measurement program 522.

As shown in fig. 13, if the processing unit 51 is in a measurable state (Y in step S11), it first functions as the data acquisition unit 211 to acquire acceleration data from the sensor 10 (step S12).

Next, the processing unit 51 determines whether or not a predetermined time has elapsed since the state in which the sensor 10 can be measured or the fall determination at step S14 was performed last (step S13), and when the predetermined time has elapsed (Y at step S13), the processing unit functions as the fall determination unit 512 to determine the fall of the sensor 10 (step S14). If the predetermined time has not elapsed (N in step S13), the processing unit 51 does not perform the drop determination in step S14.

The processing unit 51 repeats the processing of steps S12 to S14 until the management unit 515 terminates and restarts the measurement program 522 (N of step S15). Further, if the management unit 515 terminates and restarts the measurement program 522 (Y at step S15), the processing unit 51 repeats the processing at steps S12 to S14 after the measurement program becomes measurable (Y at step S11).

Fig. 14 is a flowchart showing an example of the step of the drop determination processing in step S14 in fig. 13. The processing unit 51 functions as the drop determination unit 512 and performs the processing of steps S201 to S211 in fig. 14.

First, the fall determination unit 512 refers to the fall determination result information 526 stored in the storage unit 52 (step S201).

Next, when the fall determination result information 526 indicates that the sensor 10 has not fallen (N in step S202), the fall determination unit 512 calculates a representative value of acceleration data for each detection axis of the sensor 10 (step S203).

Next, the drop determination unit 512 refers to the setting information 521 stored in the storage unit 52 (step S204).

Next, the drop determination unit 512 calculates, for each detection axis of the sensor 10, an absolute value of a difference between the representative value of the acceleration data calculated in step S203 and the gravitational acceleration value determined based on the setting information 521 (step S205).

If there are not two or more detection axes having a difference calculated in step S205 larger than the first determination value (N in step S206), and if there is not one or more detection axes having a difference calculated in step S205 larger than the second determination value (N in step S207), the drop determination unit 512 determines that the sensor 10 has not dropped (step S208).

If there are two or more detection axes having a difference calculated in step S205 larger than the first determination value (Y in step S206), or if there is one or more detection axes having a difference calculated in step S205 larger than the second determination value (Y in step S207), the drop determination unit 512 determines that the sensor 10 has dropped (step S209).

Next, the drop determination unit 512 updates the drop determination result information 526 with the determination result of step S208 or the determination result of step S209 (step S210).

Then, the drop determination unit 512 transmits the determination result of step S208 or the determination result of step S209 to the measurement device 20A via the communication unit 53 (step S211), and ends the drop determination process.

When the fall determination result information 526 indicates that the sensor 10 has fallen (Y in step S202), the fall determination unit 512 ends the fall determination process without performing the processes in steps S203 to S211.

In fig. 13 and 14, the fall determination is performed by calculating the representative value and the absolute value of the acceleration data acquired from the sensor 10 for a predetermined time every time the predetermined time elapses, but the fall determination may be performed by calculating the moving average value and the absolute value thereof or the moving median value and the absolute value thereof for the predetermined time of the acceleration data every time the acceleration data is acquired from the sensor 10.

Step S12 in fig. 13 is an example of the data acquisition step. Step S203 in fig. 14 is an example of a representative value calculation step. Steps S204, S205, S206, S207, S208, and S209 in fig. 14 exemplify a drop determination step.

2-5. action and effect

According to the sensor system 1A and the sensor drop determination method of the second embodiment described above, the same effects as those of the first embodiment can be obtained.

Further, according to the sensor system 1A and the sensor drop determination method of the second embodiment, since the communication unit 53 functions as an output unit that outputs the determination result of the drop determination unit 512 to the outside of the sensor system 1A, the risk of erroneous calculation by a device connected to the sensor system 1A based on the acceleration value detected by the dropped sensor 10 is reduced.

3. Modification example

The present invention is not limited to the embodiment, and various modifications can be made within the scope of the present invention.

For example, in the above embodiments, the sensor 10 or the sensor system 1A is installed in the building 2, but the structure to which the sensor 10 or the sensor system 1A is installed is not limited to the building, and may be, for example, a power transmission tower, a wind power generator, an electronic bulletin board of a road, or the like.

For example, in each of the above embodiments, the sensor 10 determined to have fallen is not subsequently determined to have fallen, but may be periodically determined to have fallen thereafter. Thus, when the worker returns the sensor 10 or the sensor system 1A that has fallen to the original position, the fall determination unit 212 or the fall determination unit 512 can determine that the sensor 10 has not fallen even if the worker forgets to update the fall determination result information 226 or the fall determination result information 526, and therefore the calculation unit 213 or the calculation unit 613 can perform calculation using the acceleration data output from the sensor 10.

For example, in each of the above embodiments, the sensor 10 has three detection axes, but the number of detection axes may be one, two, or four or more. When there is one detection axis of the sensor 10, the drop determination unit 212 or the drop determination unit 512 may determine that the sensor 10 drops when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravitational acceleration value determined based on the setting information 221 is larger than the determination value in the direction of the one detection axis. In the case where the number of detection axes of the sensor 10 is two or more, the drop determination unit 212 or the drop determination unit 512 may perform the drop determination using the first determination value and the drop determination using the second determination value, as in the above embodiments.

For example, in each of the above embodiments, the fall determination unit 212 or the fall determination unit 512 performs both the fall determination using the first determination value and the fall determination using the second determination value, but only either one of the fall determinations may be performed. For example, if the sensor 10 or the sensor system 1A needs to be provided in the example of fig. 4, the drop determination unit 212 or the drop determination unit 512 only needs to perform the drop determination using the first determination value, or if the sensor 10 or the sensor system 1A needs to be provided in the example of fig. 5, the drop determination unit 212 or the drop determination unit 512 only needs to perform the drop determination using the second determination value.

For example, in each of the above embodiments, the fall determination unit 212 or the fall determination unit 512 determines that the sensor 10 falls when the absolute value of the difference between the representative value of the acceleration detected by the sensor 10 and the gravity acceleration value specified based on the setting information 221 or the setting information 521 is larger than the first determination value, but the object of comparison with the first determination value is not limited to this. For example, the drop determination unit 212 or the drop determination unit 512 may determine that the sensor 10 has dropped when the difference between the absolute value of the representative value of the acceleration detected by the sensor 10 and the absolute value of the gravitational acceleration value determined based on the setting information 221 or the setting information 521 is larger than the first determination value. Accordingly, even when sensor 10 or sensor system 1A falls from the state shown in fig. 4 to the state shown in fig. 6, fall determination unit 212 or fall determination unit 512 can determine that sensor 10 falls.

Fig. 15 is a flowchart showing an example of the step of the drop determination processing in step S7 in fig. 8 in this modification. The processing unit 21 functions as the drop determination unit 212 and performs the processing of steps S301 to S314 in fig. 15.

First, the drop determination unit 212 sets the variable i to 1 (step S301), and refers to the drop determination result information 226 stored in the storage unit 22 (step S302).

Next, when the fall determination result information 226 indicates that the i-th sensor 10 has not fallen (N in step S303), the fall determination unit 212 calculates a representative value of acceleration data for each detection axis of the i-th sensor 10 (step S304).

Next, the drop determination unit 212 refers to the setting information 221 stored in the storage unit 22 (step S305).

Next, the drop determination unit 212 calculates a difference between the absolute value of the representative value of the acceleration data calculated in step S104 and the absolute value of the gravitational acceleration value determined based on the setting information 221 for each detection axis of the i-th sensor 10 (step S306).

If there are not two or more detection axes having a difference larger than the first determination value calculated in step S306 (N in step S307), the drop determination unit 212 calculates, for each detection axis, the absolute value of the difference between the representative value of the acceleration data calculated in step S304 and the gravitational acceleration value determined based on the setting information 221 (step S308).

If there is not one or more detection axes having a difference larger than the second determination value calculated in step S308 (N in step S309), the drop determination unit 212 determines that the i-th sensor 10 has not dropped (step S310).

If there are two or more detection axes having a difference calculated in step S306 larger than the first determination value (Y in step S307), or if there is one or more detection axes having a difference calculated in step S308 larger than the second determination value (Y in step S309), the drop determination unit 212 determines that the i-th sensor 10 has dropped (step S311).

Next, the drop determination unit 212 updates the drop determination result information 226 with the determination result of step S310 or the determination result of step S311 (step S312).

When the fall determination result information 226 indicates that the i-th sensor 10 falls (Y in step S303), the fall determination unit 212 does not perform the processing in steps S304 to S312, that is, the fall determination of the i-th sensor 10.

When the variable i is smaller than the total number N of the sensors 10 (Y in step S313), the drop determination unit 212 increments the variable i by 1 (step S314), repeats the processing from step S302 onward, and ends the drop determination processing if the variable i is equal to N (N in step S313).

Note that, in this modification, the flowchart showing an example of the step of the drop determination processing in step S14 in fig. 13 is the same as the case where steps S301, S313, and S314 are deleted and "sensor" is replaced with "sensor" in fig. 15, and therefore, illustration and description thereof are omitted.

Step S304 in fig. 15 is an example of the representative value calculation step. Steps S305, S306, S307, S308, S309, S310, and S311 in fig. 15 exemplify a drop determination step.

The above embodiment and modification are examples and are not limited thereto. For example, the embodiments and the modifications can be combined as appropriate. In addition, the representative value in the above embodiment and the modification may be an average value or a median value.

The present invention includes substantially the same configurations as those described in the embodiments, for example, configurations having the same functions, methods, and results, or configurations having the same objects and effects. The present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. The present invention includes a configuration that achieves the same operational effects as the configurations described in the embodiments or a configuration that can achieve the same object. The present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.