JP2020123216A - Sensing system, and sensor terminal - Google Patents

Abstract

To provide a sensing system capable of reducing consumption power.SOLUTION: A sensing system 100 includes a plurality of sensor terminals 200. One of the plurality of sensor terminals 200 becomes a master terminal 200A, and an operation mode of a slave terminal group 200B, which is a group of the sensor terminals 200 other than the master terminal 200A, can be switched based on a state of the master terminal 200A.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sensing system that monitors a plurality of objects.

In some cases, we want to monitor a set of objects such as humans, animals and plants, robots, electronic devices, and industrial machines, and analyze their behavior. In such cases, a small battery-powered sensor terminal is often attached to each object to monitor the object. The operating time of the sensor terminal is restricted by the battery capacity, and when the remaining battery level becomes empty, maintenance such as replacement or charging of the sensor terminal battery is required.

In the conventional sensing system, a plurality of sensor terminals are treated equally and all the sensor terminals operate at high speed regardless of the state of the object. Therefore, the power consumption of the plurality of sensor terminals is uniformly large, the battery consumption is large, and frequent battery replacement is required.

The present invention has been made in such a situation, and one of the exemplary objects of an aspect thereof is to provide a sensing system capable of reducing power consumption.

One aspect of the present invention relates to a sensing system. The sensing system includes a plurality of sensor terminals. One of the plurality of sensor terminals serves as a master terminal, and the operation modes of the slave terminal groups, which are sensor terminals other than the master terminal, can be switched based on the state of the master terminal.

Another aspect of the present invention relates to a sensor terminal forming a sensing stem. The sensor terminal includes a sensor, an arithmetic processing unit that processes the output of the sensor, a wireless transceiver, a battery, and a memory. When the sensor terminal is set as the master terminal, it can switch between the first mode in which the power consumption is relatively high and the speed is high, and the second mode in which the power consumption is relatively low and the speed is relatively low, and are set as the master terminal. , Always operates in the first mode and is set as a slave terminal, the first mode and the second mode are selected according to the states of other master terminals.

According to an aspect of the present invention, power consumption can be reduced.

It is a block diagram of the sensing system concerning an embodiment. It is a block diagram which shows the structural example of a sensor terminal. It is a flow chart which shows operation of a sensing system. It is a time chart which shows an example of operation of a sensing system. It is a figure which shows the livestock monitoring system.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplicated description will be omitted as appropriate. Further, the embodiments are merely examples and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

FIG. 1 is a block diagram of a sensing system according to an embodiment. The sensing system 100 monitors and analyzes the states of the plurality of objects OBJ1 to OBJN (N≧2). Multiple objects are of the same type.

The sensing system 100 includes a plurality of sensor terminals 200_1 to 200_N and a central processing unit 300. Each sensor terminal 200_# (#=1, 2,... N) is connected to the corresponding object OBJ#.

The central processing unit 300 manages the plurality of sensor terminals 200_1 to 200_N. The central processing unit 300 and the sensor terminal 200 are wirelessly connected to each other and can transmit data bidirectionally. The central processing unit 300 may be a small terminal such as a smartphone or a tablet, or a workstation or a computer. Alternatively, part or all of the central processing unit 300 may be mounted on the cloud.

A plurality of operation modes of the plurality of sensor terminals 200_1 to 200_N can be switched. Specifically, each of the sensor terminals 200 has a relatively high power consumption and a high speed in a first mode (also referred to as a high speed mode) and a relatively low power consumption and a second mode in which the speed is slow (also referred to as a low speed mode). ,) can be switched.

One of the plurality of sensor terminals 200_1 to 200_N operates as a reader. A sensor terminal that serves as a reader is collectively referred to as a master terminal 200A, sensor terminals other than the reader are collectively referred to as slave terminals, and a plurality of slave terminals are collectively referred to as a slave terminal group 200B. In FIG. 1, the sensor terminal 200_1 is the master terminal 200A, and the other 200_2 to 200_N are the slave terminal groups 200B.

The master terminal 200A always operates in the high speed mode. On the other hand, the operation mode of the slave terminal group 200B is selected based on the state of the master terminal 200A.

FIG. 2 is a block diagram showing a configuration example of the sensor terminal. The sensor terminal 200 includes one or a plurality of sensors (hereinafter collectively referred to as a sensor group) 202, an arithmetic processing unit 204, a wireless transceiver 206, a battery 208, a memory 210, and a power supply circuit 212.

The type of the sensor 202 is not particularly limited, and is selected according to the type of the object OBJ. For example, the sensor 202 may be a temperature sensor, an acceleration sensor, an angular velocity sensor (gyro sensor), an image sensor, or the like, but is not limited thereto.

The arithmetic processing unit 204 processes the output of the sensor group 202. The wireless transceiver 206 transmits to the central processing unit 300 primary data output from the sensor and/or secondary data obtained by the arithmetic processing unit 204 processing the primary data. The communication method of the wireless transceiver 206 is not particularly limited, but LPWA (Low Power Wide Area), wireless LAN (Local Area Network), Bluetooth (registered trademark), ZigBee (registered trademark), or the like can be used.

If multiple sensors are provided, the secondary data may be multimodal data. The memory 210 is provided in association with the arithmetic processing device 204. The battery 208 is a power source for electronic components mounted on the sensor terminal 200. The power supply circuit 212 receives the voltage of the battery 208 (battery voltage) and lowers (or increases) the voltage to generate a power supply voltage to be supplied to the arithmetic processing device 204, the memory 210, and the sensor 202. The power supply circuit 212 can include multi-channel power supplies, and is configured such that the power supply voltage level can be set individually for each channel.

The above-described first mode (high speed mode) can be associated with a mode in which the operating frequency of the arithmetic processing device 204 is relatively high, and the second mode (low speed mode) is in which the operating frequency of the arithmetic processing device 204 is relatively high. Can be associated with lower modes.

When an electronic circuit such as the arithmetic processing unit 204 is modeled as a simple capacitor, its power consumption is
P=f·C·V ²
Becomes f is the operating frequency, C is the capacitance of the capacitor, and V is the power supply voltage. When the operating frequency f is lowered, the processing capability is lowered, but in return, the power consumption P can be lowered. When lowering the operating frequency f, the power supply voltage V can be lowered in combination with it, and thus the power consumption P can be further lowered. There is also a method of reducing the power consumption by lowering the power supply voltage Vdd generated by the power supply circuit 212, and the operating frequency of the arithmetic processing device 204 lowers accordingly.

The selection of the master terminal will be described. In the present embodiment, the central processing unit 300 selects the master terminal. As described above, the data (primary data or secondary data) of the plurality of sensor terminals 200 is collected in the central processing unit 300. The central processing unit 300 can determine the master terminal by statistically analyzing these data.

For example, the sensor terminal attached to the earliest active one of the plurality of objects can be selected as the master terminal. In this case, the central processing unit 300, based on the primary data or the secondary data obtained from the plurality of sensor terminals, for each of the plurality of objects, a plurality of first index data having a correlation with the activity or the activity. The sensor terminal that is generated and the value of the plurality of first index data is first activated may be selected as the master terminal.

The central processing unit 300 may repeat the process of redetermining the master terminal at a predetermined update timing. The redetermination of the master terminal may be performed every predetermined period. For example, it may be every several hours, every day, or every several days, and the cycle may be determined according to the type of the object.

Next, the control of the operation mode of the slave terminal group based on the state of the master terminal will be described. In the present embodiment, the central processing unit 300 also controls the operation mode of the slave terminal group. The central processing unit 300 knows which of the plurality of terminals is the master terminal. Therefore, the central processing unit 300 may set the slave terminal group to the first mode when the state of the master terminal satisfies the predetermined condition, and may set the slave terminal group to the second mode when the state does not satisfy the predetermined condition.

Regarding a plurality of objects OBJ, there are a state in which detailed data should be acquired (a state of high interest) and a state in which such detailed data is not required (low interest). The fact that the master terminal satisfies the predetermined condition can be associated with a state of high interest. For example, when the target object is performing (or is not performing) a specific motion/activity, if a detailed analysis is desired for the target object, a predetermined condition may be defined in association with the specific motion.

As the index indicating the state of the master terminal, either the primary data output from any one of the sensors 202 or the secondary data obtained by processing the primary data (referred to as monitoring data) can be used. The central processing unit 300 may set the slave terminal group in the second mode when the monitoring data satisfies the predetermined condition.

For example, the central processing unit 300 compares the monitoring data with a threshold value, maintains or changes the slave terminal group to the second mode when the monitoring data is lower than the threshold value, and when the monitoring data exceeds the threshold value, The slave terminal group may be set to the first mode.

As shown in FIG. 2, when each sensor terminal 200 includes a plurality of sensors 202, monitoring data may be generated for each sensor 202 and a predetermined condition may be set for each monitoring data.

In one embodiment, one sensor 202 can be an acceleration sensor and another sensor 202 can be an angular velocity sensor. In this case, the monitoring data based on the output of the acceleration sensor is compared with the corresponding threshold value, and the monitoring data based on the output of the angular velocity sensor is compared with the corresponding threshold value. Then, when any of the monitoring data exceeds the threshold value, the slave terminal group may be set to the first mode.

The above is the configuration of the sensing system 100. Next, the operation will be described.
FIG. 3 is a flowchart showing the operation of the sensing system 100. First, the master terminal is determined (S100). Then, the master terminal is set to the first mode (S102), and the other slave terminal groups are set to the second mode (S104).

Then, the state of the master terminal is monitored (S106). When the state of the master terminal satisfies the predetermined condition (Y of S106), the slave terminal group is set to the first mode (S108). When the state of the master terminal does not satisfy the predetermined condition (N in S106), the slave terminal group is maintained in the second mode, or when the slave terminal group is once changed to the first mode, is returned to the second mode.

If it is the update timing of the master terminal (Y in S110), the process returns to step S100 and the master terminal is re-determined (S100). When it is not the update timing (N in S110), the process returns to step S106, and the state monitoring of the master terminal is continued.

FIG. 4 is a time chart showing an example of the operation of the sensing system 100. The master terminal always operates in the first mode. The slave terminal group operates in the first mode and the second mode in a time division manner based on the state of the master terminal. The power consumption of the entire system can be significantly reduced while the slave terminal group operates in the second mode.

The above is the operation of the sensing system 100. According to this sensing system 100, by deciding one of the plurality of sensor terminals as the master terminal and treating it unequally with the slave terminal group, it is possible to reduce the power consumption of the entire system.

Next, an example of a specific application of the sensing system 100 will be described. In one application, the object OBJ is a livestock such as a cow and the sensing system 100 is used to manage the health of the livestock. FIG. 5 is a diagram showing a livestock monitoring system. In this example, the sensor terminal 200 includes a temperature sensor, an angular velocity sensor, and an acceleration sensor as the sensor terminal 200. The sensor terminal 200 may further include an image sensor.

For example, in the central processing unit 300, the sensor terminal 200 attached to the earliest awakening of the plurality of cows (object OBJ) is the master terminal 200A, and the sensor terminals 200 attached to the remaining cows are the slave terminal groups. 200B. Whether the cow is awake or sleeping can be determined based on the output of the temperature sensor, the output of the acceleration sensor, the output of the angular velocity sensor, or any combination thereof. You may use the discriminator which mounted the prediction model obtained by learning.

The central processing unit 300 monitors the state of the master terminal 200A. For example, the central processing unit 300 may set the slave terminal group 200B in the first mode on condition that the cow to which the master terminal 200A is attached has moved 10 steps. In this case, the monitoring data is the number of steps of the cow and can be generated based on the output of the acceleration sensor. The threshold value to be compared with the monitoring data is 10.

The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that this embodiment is merely an example, and that various modifications can be made to the combinations of the respective constituent elements and the respective processing processes, and that such modifications are also within the scope of the present invention. is there. Hereinafter, such modified examples will be described.

(Modification 1)
In the above-described embodiment, depending on the conditions under which the central processing unit 300 selects the master terminal 200A, a situation may occur in which a specific sensor terminal 200 is frequently selected as the master terminal 200A. For example, in a livestock health care system, a particular cattle always wakes up first. In this case, the batteries of the sensor terminals attached to the specific object are quickly consumed, and the consumption of the batteries of the other sensor terminals is suppressed. Therefore, although the frequency of battery replacement increases, only the battery of a specific sensor terminal needs to be replaced, and in some cases it may be possible to enjoy it.

Therefore, in Modification 1, the central processing unit 300 may not always dynamically select the master terminal 200A, but the same sensor terminal 200 may always be fixedly operated as the master terminal 200A. In this case, only the battery of the master terminal 200A needs to be replaced.

(Modification 2)
The central processing unit 300 may determine the master terminal 200A so that the cumulative power consumption of the plurality of sensor terminals 200 is equalized. For example, the central processing unit 300 may select the plurality of sensor terminals 200 as the master terminal 200A in a predetermined order. Alternatively, the central processing unit 300 may monitor the power consumption of the plurality of sensor terminals 200 and select the master terminal 200A based on the monitoring result.

As a result, the batteries of the plurality of sensor terminals 200 are consumed evenly, and it is possible to enjoy the advantage that the frequency of battery replacement can be reduced.

(Modification 3)
In the second mode, the operation speed of the memory 210 may be reduced in addition to or instead of the arithmetic processing unit 204 of the slave terminal group 200B. As a result, the power consumption of the slave terminal group 200B can be reduced.

(Modification 4)
The memory 210 may be switchable between (i) a high speed mode in which the writing speed is high and the data retention time is short, and (ii) a low speed mode in which the writing speed is low and the data retention time is long. The short data retention time means that the refresh frequency is high and thus the power consumption increases. On the contrary, a long data retention time means that the frequency of refresh can be reduced, and thus power consumption is suppressed. For example, the high speed mode may be a mode in which the write voltage to the cell is relatively high, and the low speed mode may be a mode in which the write voltage to the cell is relatively low.

The memory of the master terminal 200A may be operated in the high speed mode, and the memory of the slave terminal group 200B may be operated by switching between the high speed mode and the low speed mode.

(Modification 5)
The central processing unit 300 may dynamically set the threshold value to be compared with the monitoring data. For example, the threshold value may be dynamically set based on the data acquired by the master terminal 200A.

(Modification 6)
In the embodiment, the central processing unit 300 monitors the state of the master terminal 200A, but not limited to this, the master terminal 200A monitors its own state and determines whether or not a predetermined condition is satisfied. You can In this case, the arithmetic processing unit 204 of the master terminal 200A may be mounted so as to compare the monitoring data based on the output of the sensor 202 with a threshold value. In this case, the operation mode of the slave terminal group 200B may be set via the central processing unit 300. Alternatively, a protocol that allows the sensor terminals 200 to communicate with each other without going through the central processing unit 300 may be adopted, and the master terminal 200A may directly notify the slave terminal group 200B of the operation mode.

(Modification 7)
In the embodiment, one of the plurality of sensor terminals 200 is the master terminal, but the present invention is not limited to this, and a plurality of master terminals may exist.

Although the present invention has been described using specific terms based on the embodiments, the embodiments merely show the principle and application of the present invention, and the embodiments are defined in the claims. Many modifications and changes in arrangement are possible without departing from the concept of the present invention.

100 sensing system 200 sensor terminal 202 sensor 204 arithmetic processing unit 206 wireless communication means 208 battery 210 memory 212 power supply circuit 300 central processing unit 302 arithmetic processing unit 200A master terminal 200B slave terminal group

Claims (14)

Equipped with multiple sensor terminals,
One of the plurality of sensor terminals serves as a master terminal, and an operation mode of a slave terminal group, which is a sensor terminal other than the master terminal, can be switched based on a state of the master terminal. Each of the plurality of sensor terminals can switch between a first mode in which the power consumption is relatively large and the speed is relatively fast, and a second mode in which the power consumption is relatively small and the speed is relatively slow,
The master terminal always operates in the first mode,
The sensing system according to claim 1, wherein the operation mode of the slave terminal group is selected based on the state of the master terminal. Further comprising a central processing unit for managing the plurality of sensor terminals,
Each of the plurality of sensor terminals,
A sensor,
An arithmetic processing unit that processes the output of the sensor;
Wireless transceiver,
A battery,
Including
The wireless transceiver transmits primary data output from the sensor and/or secondary data obtained by processing the primary data by the arithmetic processing unit to the central processing unit. The sensing system according to 1 or 2. The sensing system according to claim 3, wherein the central processing unit determines the master terminal based on data received from the plurality of sensor terminals. The sensing system according to claim 4, wherein the central processing unit repeats a process of determining the master terminal. The sensing system according to claim 4 or 5, wherein the central processing unit determines the master terminal so that accumulated power consumption of the plurality of sensor terminals is equalized. The said central processing unit controls the operation mode of the said slave terminal group based on the data received from the said master terminal, The sensing system in any one of Claim 3 to 6 characterized by the above-mentioned. 7. The sensing device according to claim 3, wherein in the master terminal, the arithmetic processing unit controls an operation mode of the slave terminal group based on the primary data or the secondary data. system. 9. The sensing system according to claim 3, wherein the sensor terminal has a different operation frequency of the arithmetic processing device for each operation mode. The sensing system according to claim 3, wherein the sensor terminal has a different power supply voltage of the arithmetic processing device for each operation mode. Each of the plurality of sensor terminals further includes a memory,
The memory can be switched between (i) a high-speed mode in which the writing speed is high and the data retention time is short, and (ii) a low-speed mode in which the writing speed is low and the data retention time is long. The sensing system according to any one of 3 to 10. The memory of the master terminal operates in the high speed mode,
The sensing system according to claim 11, wherein the memory of the slave terminal group operates in the high speed mode or the low speed mode. 13. The sensing system according to claim 11, wherein a write voltage to the memory is relatively high in the high speed mode, and a write voltage to the memory is relatively low in the low speed mode. A sensor terminal that constitutes a sensing system,
A sensor,
An arithmetic processing unit that processes the output of the sensor;
Wireless transceiver,
A battery,
Memory and
Equipped with
The sensor terminal can switch between a first mode in which the power consumption is relatively large and the speed is high, and a second mode in which the power consumption is relatively low and the speed is relatively low,
When set as a master terminal, it always operates in the first mode,
A sensor terminal, wherein when set as a slave terminal, the first mode and the second mode are selected according to the states of other master terminals.

Images