JP7218848B2 - Sensor device and livestock management system - Google Patents

Description

The present invention relates to a sensor device and a livestock management system using the sensor device.

There are a large number of livestock raised in breeding farms such as piggeries and cowsheds, and it is difficult to manage all of them manually. Proposed. In a livestock management system, a sensor device having a power generation unit that generates electric power and a transmission unit that transmits power generation information of the power generation unit is attached to livestock to estimate the state of the livestock. When the power generation unit is a solar power generation unit, based on the power generation information of the power generation unit, the movement timing between the livestock barn and the grazing land is determined. Further, when the power generation unit is vibration power generation, estrus is estimated from the amount of activity based on the power generation information of the power generation unit.

Such a sensor device attached to livestock consumes a certain amount of power because it is necessary to periodically measure the condition of the livestock and transmit data to an external device. However, since it is necessary to manage many livestock, it is necessary to avoid work such as replacing the battery of the sensor device, and there has been a demand for a device that can operate for a long period of time. In addition, it is desirable to be as small and lightweight as possible so that livestock do not feel stressed by the sensor device.

In addition, it is desirable for these livestock management systems to operate equipment by power generation such as sunlight or electromagnetic waves. Patent Literature 2 describes a sensor device that rectifies an induced electromotive force generated by an antenna absorbing electromagnetic waves, stores the induced electromotive force in a power storage unit, and operates a sensor using the stored power. Thereby, a sensor device having a contactless charging function and a signal transmitting function can be realized.

WO2016/181604 JP-A-2008-65660

However, in the livestock management system described in Patent Literature 1, the information obtained from the sensor device is only the power generation state, and other information related to livestock cannot be obtained. In addition, the information that can be obtained by analyzing the data obtained from the amount of power generated by the power generation unit is limited, and it was required to collect a wide range of data such as the body temperature of livestock, the amount of food eaten, and the amount of movement.

In the sensor device described in Patent Document 2, it is necessary to increase the number of turns of the antenna to increase the winding diameter in order to improve the reception sensitivity and efficiently generate power. It was difficult to apply it to a sensor device that In addition, since a plurality of substrates are connected by electromagnetic coupling between antennas, a plurality of antennas are required, increasing power consumption and manufacturing costs.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sensor device and a sensor system capable of collecting necessary information while minimizing power consumption.

In order to solve the above problems, a first invention is a sensor device that transmits measurement data to an external device by wireless communication, comprising a power supply unit that supplies power, and the power supplied from the power supply unit. a plurality of sensors that operate and sense the surrounding environment; a storage unit that stores a plurality of environmental data sensed by the plurality of sensors ; To all the sensors and the communication unit provided in the sensor device of the power supply unit, and a communication unit that performs unidirectional communication only for transmission, which transmits the plurality of environmental data to the external device by the wireless communication. and time management means for managing time, wherein the switching means controls the sensor device at a predetermined timing based on a signal from the time management means. The supply of power to all the sensors and the communication unit provided in the device and the interruption of the power are repeated, and the switching means from the power supply unit to all the sensors and the communication unit provided in the sensor device When the power is supplied to the communication unit at the same time, the sensor performs sensing and the communication unit transmits the plurality of environmental data obtained by the sensing to the external device through the wireless communication, After transmitting the environmental data to the external device, the switching means simultaneously cuts off the power from the power supply unit to all the sensors provided in the sensor device and the communication unit, and the communication unit is configured to: The sensor device is characterized by transmitting a plurality of the environment data collectively to the external device only once during a period from when the power is supplied from the power supply unit until the power is cut off .

In a second invention, in the sensor device according to the first invention, the power supply unit includes a power generation unit that generates power from external energy, a rectifier that rectifies the power generated by the power generation unit, and the and a power storage unit that stores electric power rectified by the rectifier, wherein the power generation unit is at least one of photovoltaic power generation and electromagnetic wave power generation.

In a third invention, a sensor device for transmitting measurement data to an external device by wireless communication, comprising: a power generation unit that supplies power and generates power from external energy; and a rectifier that rectifies the power generated by the power generation unit. a power storage unit that stores the power rectified by the rectifier; a plurality of sensors that operate on the power supplied from the power supply unit and sense the surrounding environment; a communication unit that operates on the power supplied from the supply unit and performs unidirectional communication that only transmits environmental data sensed by the sensor to the external device via the wireless communication; and a sensor device of the power supply unit. and switching means for switching between supply and interruption of the power to all the sensors and the communication unit, wherein the switching means switches the power supply to the sensors when the voltage of the power storage unit reaches a predetermined value. The power supply to all the sensors and the communication unit provided in the device and the power cutoff are repeated, and the switching means supplies all the sensors provided in the sensor device from the power supply unit. and when the power is supplied to the communication unit at the same time, the sensor performs sensing and the communication unit transmits the environmental data obtained by the sensing to the external device through the wireless communication, and the communication unit transmits the After transmitting the environmental data to the external device, the switching means simultaneously cuts off the power from the power supply unit to all the sensors provided in the sensor device and the communication unit, and the communication unit The sensor device is characterized by transmitting a plurality of the environment data collectively to the external device only once during a period from when the power is supplied from a power supply unit until the power is cut off .

In a fourth invention, the sensor device according to any one of the first invention to the third invention attached to livestock, the external device receiving and storing the environmental data from the communication unit, and the sensor a receiver that receives the environmental data from a device, the receiver recognizes signal strength from the sensor device within a reception area, and the external device receives radio waves from the sensor device. A livestock management system characterized by associating and storing an identifier for identifying the receiver received from the sensor device and the strength of the signal received from the sensor device.

According to the first invention, the switching means supplies power to the sensor section and the communication section only when the sensor section senses and the communication section transmits environmental data. Standby power can be reduced. In addition, since environmental data obtained by sensing by the sensor section is transmitted to the external device by the communication section, there is a one-to-one relationship between sensing by the sensor section and communication by the communication section. As a result, it is possible to transmit the environment data sensed with the minimum required amount of power to the external device.

According to the second invention, since the power supply unit uses power generated by solar power generation and/or electromagnetic wave power generation, it is not necessary to mount a battery, battery, or the like. This eliminates the need for a circuit for managing the power supply, thereby reducing the power consumption of the sensor device. Moreover, since electric power is generated by photovoltaic power generation and/or electromagnetic wave power generation, micro energy harvesting using natural energy can be realized. Furthermore, the sensor device can be manufactured at a low cost compared to batteries and cells.

According to the third invention, since the storage unit stores environmental data for one past time and overwrites the past environmental data when new environmental data is measured, the past environmental data that has been measured is not stored. When storing past environmental data, it is necessary to constantly supply power to the communication unit in order to operate the storage unit. Power consumption can be kept low.

According to the fourth invention, since the signal strength of the sensor device mounted on the livestock and the identifier of the receiver are associated with each other and stored in the external device, the distance between the sensor device and the receiver is estimated from the signal strength, thereby enabling GPS It is possible to detect the position information of livestock with minimum power consumption without using Also, by overlapping the reception areas of a plurality of receivers, it is possible to analyze the signal strengths from the plurality of receivers and detect position information more accurately.

1 is a schematic diagram of a sensor system according to a first embodiment of the invention; FIG. 1 is a block diagram of a sensor device of a sensor system according to a first embodiment of the invention; FIG. 4 is an operation flowchart of the sensor device according to the first embodiment of the present invention; 4 is a time chart of the sensor device according to the first embodiment of the invention; 4 is a graph showing temperature detection results of the sensor device according to the first embodiment of the present invention; 4 is a graph showing pressure detection results of the sensor device according to the first embodiment of the present invention; FIG. 4 is a schematic diagram illustrating a position information detection method of the sensor system according to the first embodiment of the present invention; 5 is a graph showing detection results of position information of the sensor system according to the first embodiment of the present invention; 4 is a flow chart of a sensor device of a sensor system according to a second embodiment of the invention; 6 is a time chart of the sensor device of the sensor system according to the second embodiment of the present invention;

A sensor system 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG. The sensor system 1 is attached to a plurality of cows 10 and periodically measures surrounding environmental data to manage the cows 10 . The livestock to be managed is not limited to cattle 10, and can be applied to, for example, pigs, horses, sheep, chickens, pet animals, and the like. Moreover, this system can be applied not only to livestock but also to animals such as fish, birds, and insects. The application field of the sensor system 1 is not limited to livestock management and monitoring, and can be used as various IoT (Internet of Things) devices.

A sensor system 1 includes a sensor device 2 , a receiver 3 , a PC terminal 4 and a mobile terminal 5 . The sensor device 2 is integrated with an ear tag attached to the ear of the cow 10 . As a result, the sensor device 2 is less likely to come off from the cow 10 even when the cow 10 rubs against a fence or the like or the cow 10 collides with each other. It is desirable that the sensor device 2 is attached to a location that does not cause stress to the cow 10. For example, the sensor device 2 may be attached around the tail, on the back, on the legs, etc., in addition to the ear tag.

As shown in FIG. 2 , the sensor device 2 has a power supply section 21 , a communication section 22 , a sensor section 23 and switching means 24 . In FIG. 2, a thick solid line indicates power supply, and a solid line with thin arrows indicates digital or analog communication. The power supply unit 21 has a power generation unit 25 , a power storage unit 26 , a rectifier 27 , and a power control unit 28 . The power generation unit 25 is a micro energy harvester that generates electric power from the surrounding environment. For example, the power generation unit 25 generates electric power based on heat, light, vibration, radio waves such as electromagnetic waves, or organic matter such as plants. In the present embodiment, the power generation unit 25 generates electric power by photovoltaic power generation, but power generation by electromagnetic waves may be used, or a hybrid system combining photovoltaic power generation and electromagnetic wave power generation may be used. As a result, the sensor device 2 can be stably operated even when there is no sunlight for a long time or when the cow 10 is in the barn for a long time.

The power storage unit 26 is provided to store power generated by the power generation unit 25 . Electric power generated by the power generation unit 25 is stored in the power storage unit 26 and used to operate the communication unit 22 or the sensor unit 23 . Although a small supercapacitor is used as power storage unit 26 in the present embodiment, it is not limited to this and may be a lithium ion capacitor, a ceramic capacitor, a film capacitor, a tantalum capacitor, a lithium ion battery, or the like. Moreover, you may use these electrical storage materials in combination according to the purpose of use. Moreover, the capacitance of the electric storage unit 26 is preferably in the range of 0.01 F to 2.2 F, and particularly in the range of 0.01 F to 0.1 F for miniaturization of the sensor device 2 . Since a supercapacitor is used as the power storage unit 26, it can be charged and discharged even in a low-temperature environment, and problems such as a decrease in power storage efficiency due to outside air temperature are unlikely to occur. Although the outside temperature of the cowshed may drop below freezing in winter, the power storage unit 26 can store the electric power generated by the power generation unit 25 without being affected by the temperature. In addition, even if the battery is repeatedly charged and discharged, it does not easily deteriorate, and the product life is extended.

The rectifier 27 is composed of a plurality of diodes or the like, and the power generated by the power generation section 25 is rectified by the rectifier 27 and stored in the power storage section 26 . The power control unit 28 monitors the voltage of the storage unit 26 and switches the switching means 24 . In this embodiment, the power control unit 28 has an RTC 28A (Real Time Clock) and a booster circuit 28B. The RTC 28A manages the time set by date and year. Since the power consumption of the RTC 28A is very small, the power stored in the power storage unit 26 is consumed for operation.

Based on the signal from the RTC 28A, the power control unit 28 controls the energization time during which the power supply unit 21 supplies power to the communication unit 22 and the sensor unit 23, and the power supply unit 21 supplies power to the communication unit 22 and the sensor unit 23. The stop time when no supply is performed is measured. In this embodiment, the energization time is set to 2 seconds, the stop time is set to 4 minutes and 58 seconds, and the cycle from sensing by the sensor unit 23 to the next sensing is set to 5 minutes. When the stop time is switched to the energization time, the power control unit 28 turns on the switching means 24 to supply power from the power supply unit 21 to the communication unit 22 and the sensor unit 23, and when the energization time ends and the stop time comes again. The switching means 24 is turned off to stop the power supply to the communication section 22 and the sensor section 23 . The energization time and stop time can be arbitrarily set according to the capacitance of the electricity storage unit 26, the power generation state of the power generation unit 25, and the like.

The power supplied from the power supply unit 21 to the communication unit 22 and the sensor unit 23 is stepped up to the driving voltage of the communication unit 22 and the sensor unit 23 by the step-up circuit 28B.

The communication section 22 has a data transmission section 29 and a control section 30 . The data transmission unit 29 has a communication circuit and an antenna for communicating with the receiver 3, and performs data communication with the receiver 3 using Bluetooth (registered trademark). The communication method between the data transmission unit 29 and the receiver 3 is not limited to this, and includes Wifi (registered trademark), Zigbee (registered trademark), LPWA (Low Power Wide Area), 920 MHz band wireless communication, wireless LAN, 3G or 4G. mobile communication, infrared communication, or the like. During data communication between the communication unit 22 and the receiver 3 , the identifier assigned to each sensor device 2 is transmitted together with the environmental data measured by the sensor unit 23 . As a result, the PC terminal 4 and the portable terminal 5 can identify which sensor device 2 is responsible for the environmental data obtained. The identifier may be assigned to the sensor device 2 in advance, or may be assigned when the sensor device 2 and the receiver 3 start communication.

The control unit 30 is a microcomputer that controls the communication unit 22 and the sensor unit 23, and has an A/D conversion unit 30A and a storage unit 30B. The A/D conversion section 30A converts the analog signal from the sensor section 23 into a digital signal. The storage unit 30B has a ROM (Read Only Memory) that stores programs executed by the control unit 30 and a RAM (Random Access Memory) that stores environmental data measured by the sensor unit 23 . The RAM also functions as a working memory when the control unit 30 executes programs. The storage unit 30B stores environmental data measured by the sensor unit 23 for only one past measurement, and when new environmental data is measured, the previous environmental data stored is overwritten.

The communication unit 22 and the sensor unit 23 are connected by serial communication through an I2C bus. The sensor unit 23 can measure various environmental data, and can measure at least one of temperature, humidity, illuminance, atmospheric pressure, CO2 concentration, methane gas concentration, and wind force. In this embodiment, the sensor unit 23 can measure temperature and humidity. The control unit 30 converts the digital signal received from the sensor unit 23 through serial communication into numerical data by incorporating it into a predetermined calculation formula, stores the numerical data in the storage unit 30B, and receives the numerical data in the data transmission unit 29. hand over. The data transmission unit 29 transmits environment data to the receiver 3 by wireless communication.

The switching means 24 is on the power supply line through which the power supply unit 21 supplies power to the communication unit 22 and the sensor unit 23, and switches the power supply control unit 28 to supply and cut off power to the communication unit 22 and the sensor unit 23. provided for switching. The switching means 24 is composed of an element such as a transistor, and may be composed of a junction FET or a MOSFET.

A plurality of receivers 3 are provided so as to cover the ranch and barn, which are the active areas of the cows 10 , and the environmental data transmitted from the data transmitter 29 are received by at least one receiver 3 . The environmental data received by the receiver 3 is assigned an identifier of the receiver 3 and transmitted to the PC terminal 4 via the external network 6 . At this time, the mobile terminal 5 can browse the environmental data transmitted to the PC terminal 4 via the external network 6 . The PC terminal 4 is placed away from the barn, and the portable terminal 5 is held by a worker who manages the barn. A cowshed worker can grasp the condition of the cow 10 in real time by using the mobile terminal 5 . The PC terminal 4 corresponds to the external device of the invention.

Next, sensing by the sensor device 2 will be described with reference to FIGS. 3 and 4. FIG. 4(a) shows switching between the ON state and the OFF state of the switching means 24, FIG. 4(b) shows changes in the current value in the communication section 22, and FIG. 4(c) shows changes in the current value in the sensor section 23. represents change.

Electric power generated by the power generation unit 25 by photovoltaic power generation is stored in the power storage unit 26 via the rectifier 27 . The power control unit 28 determines whether or not the stop time has switched to the energization time based on the signal from the RTC 28A (S1). When the power supply time has changed (S1: YES), the power control unit 28 turns on the switching means 24 and supplies power to the communication unit 22 and the sensor unit 23 (S2, t1).

When power is supplied from the power supply unit 21, the communication unit 22 is initialized (reset) by the control unit 30 starting a program at approximately the same timing as t1. As shown in FIG. 4B, the communication unit 22 consumes a predetermined amount of power at the timing of program initialization. The control unit 30 reads the identifier (ID) assigned to the sensor device 2 and the minimum necessary information from the storage unit 30B (t2). The minimum necessary information here means, for example, manufacturer information of each element, necessary information of Bluetooth Beacon, ID information of system and module, revision of microcomputer software, sensor information indicating what kind of sensor is connected, etc. There is As shown in FIG. 4B, the communication unit 22 and the sensor unit 23 start I2C bus communication (t3), and the control unit 30 transmits a temperature information request to the sensor unit 23 (t4). The sensor unit 23 detects the outside air temperature in response to the temperature information request from the communication unit 22 (t5, S3), and transmits the detected data to the control unit 30 through serial communication. The current value of the sensor unit 23 at t5 is 150 mA.

The control unit 30 converts the detection data received from the sensor unit 23 into digital data by the A/D conversion unit 30A, converts the data into numerical data using a predetermined calculation formula, and stores the data in the storage unit 30B as environmental data ( S4, t6). In this embodiment, since the temperature and humidity can be detected (S5: NO), the control unit 30 again transmits a humidity information request to the sensor unit 23 through I2C bus communication (t7). The sensor unit 23 detects humidity in response to the humidity information request from the communication unit 22 (t8, S3), and transmits the detected detection data to the control unit 30 through serial communication.

The control unit 30 converts the detection data received from the sensor unit 23 into digital data in the A/D conversion unit 30A, converts the data into numerical data using a predetermined calculation formula, and stores the data in the storage unit 30B as environmental data. (S4, t9). The control unit 30 determines that all the data has been acquired because the environmental data of the temperature and humidity have been acquired (S5: YES), and receives the environmental data of the temperature and humidity from the data transmission unit 29 by wireless communication with an identifier attached. to the machine 3 (S6, t10). The current value of the communication unit 22 at t10 is 10 mA.

In FIGS. 4(b) and 4(c), from t1 to t11, which is the energization time, standby power is consumed in the communication unit 22 and the sensor unit 23 in addition to power consumption for communication, etc. The power consumption in the communication unit 22 and the sensor unit 23 is zero from t10 to t1. The standby current value of the communication unit 22 and the sensor unit 23 in this embodiment is 60 nA, and the average current value of the communication unit 22 and the sensor unit 23 during the energization time is about 10 mA. The power consumption at is several mW. Specifically, it is 5 mW for the pulse during wireless communication at t10, several μW (maximum 10 μW) during access to the sensor unit 23 at t4 and t7, and on the order of nW during standby from t1 to t11.

When the power supply control unit 28 determines that the energization time has passed, that is, 2 seconds have passed since t1 (t11, S7: YES), it turns off the switching means 24 (S8), and the energization time after 4 minutes and 58 seconds. (S1: NO).

The receiver 3 that has received the environmental data from the data transmitter 29 adds the identifier of the receiver 3 and the signal strength from the data transmitter 29 and transmits the environmental data to the PC terminal 4 . The PC terminal 4 stores the identifier of the receiver 3, the identifier of the sensor device 2, the signal strength, and the environmental data in association with each other.

FIG. 5 shows a table comparing the temperature of the cow 10 detected by the sensor device 2 and the outside air temperature. In this embodiment, the sensor device 2 is attached to the ear tag of the cow 10 to measure the body temperature of the cow 10 indirectly. The temperature measured by the sensor device 2 is close to the average body temperature of the cow 10 without being affected by the outside air temperature. By managing the body temperature of the cow 10, the state of pregnancy, estrus, infectious disease, etc. can be grasped.

FIG. 6 shows a graph when the atmospheric pressure is measured by the sensor unit 23. As shown in FIG. At this time, the energization time is set to 2 seconds, the stop time is set to 8 seconds, and one cycle is set to 10 seconds. In the measurement results, the measured pressure locally increases in the area A, which is due to the cow 10 lowering its head. Therefore, by analyzing the measurement result of the atmospheric pressure, it is possible to measure the frequency with which the cow 10 eats grass or the like.

Next, positional information detection of the cow 10 using the sensor device 2 will be described with reference to FIGS. 7 and 8. FIG. A plurality of receivers 3 are installed so as to cover the entire area of the ranch and cow barn where cows 10 are grazed, and the receivers 3 can detect the sensor device 2 existing within the reception area 3A. can. The reception area 3A is a circle with a radius of about 20 m, but can be arbitrarily set according to the types of the receiver 3 and the data transmission section 29. FIG.

The receivers 3 include a first receiver 31 having a first reception area 31A, a second receiver 32 having a second reception area 32A, a third receiver 33 having a third reception area 33A, and a fourth reception area 33A. and a fourth receiver 34 having an area 34A. The receiver 3 can detect the strength of the signal received from the data transmitter 29 of the sensor device 2 within the reception area 3A, and can estimate the distance between the receiver 3 and the sensor device 2 based on the signal strength. A first cow 11 , a second cow 12 and a third cow 13 are present in the reception area 3 A of the receiver 3 .

Since the first cow 11 is in the region where the first reception area 31A and the second reception area 32A overlap, it is detected by the first receiver 31 and the second receiver 32 with substantially the same signal strength. As a result, it is determined that the first cow 11 is at a position where the first reception area 31A and the second reception area 32A overlap and is at approximately the same distance from the first receiver 31 and the second receiver 32. can do.

The second cow 12 is detected by the second receiver 32 and the third receiver 33 because it is in the area where the second reception area 32A and the third reception area 33A overlap. Here, since the second bull 12 is closer to the third receiver 33 side, the signal strength detected by the third receiver 33 is stronger than the signal strength detected by the second receiver 32 . As a result, it can be determined that the second cow 12 is at a position where the second reception area 32A and the third reception area 33A overlap and is near the third receiver 33. FIG.

The third cow 13 is detected only by the fourth receiver 34 because it is in the fourth reception area 34A of the fourth receiver 34 . This confirms that the third cow 13 is at the farthest position within the fourth reception area 34A.

FIG. 8 is a graph showing the relationship between the signal strength of the detection signal detected by the first receiver 31 and time. It is confirmed that the first cow 11 is in the first receiving area 31A from 22:30 to about 23:00. It is confirmed that the second cow 12 is in the first reception area 31A for a relatively long time from 3:30 to 6:00. Although the third cow 13 was temporarily located in the first reception area 31A, it is considered that it temporarily entered the periphery of the first reception area 31A due to the weak signal strength. By combining and analyzing the detection signal of the first receiver 31 and the detection signal of the other receiver 3, the positional information of the cow 10 can be grasped.

According to such a configuration, the switching means 24 supplies power to the sensor unit 23 and the communication unit 22 only when the sensor unit 23 senses and the communication unit 22 transmits environmental data. The standby power consumption of the unit and the sensor unit can be reduced. In addition, since environmental data obtained by sensing by the sensor unit 23 is transmitted to the PC terminal 4, which is an external device, by the communication unit 22, there is a one-to-one relationship between sensing by the sensor unit 23 and communication by the communication unit 22. in nature. As a result, environmental data sensed with the minimum amount of electric power required can be transmitted to the PC terminal 4 .

With such a configuration, the power supply unit 21 uses power generated by solar power generation and/or electromagnetic wave power generation, so there is no need to mount a battery or the like. This eliminates the need for a circuit for managing the power supply, and the power consumption of the sensor device 2 can be reduced. Moreover, since electric power is generated by photovoltaic power generation and/or electromagnetic wave power generation, micro energy harvesting using natural energy can be realized. Furthermore, the sensor device can be manufactured at a low cost compared to batteries and batteries.

According to such a configuration, the storage unit 30B stores the past environmental data and overwrites the past environmental data when new environmental data is measured, so the past environmental data that has been measured is not stored. In the case of storing past environmental data, power supply to the communication unit 22 is always required to operate the storage unit 30B, but in the present invention, power supply to the communication unit 22 is unnecessary during non-communication Therefore, the power consumption can be kept low.

According to such a configuration, since the signal strength of the sensor device 2 mounted on the cow 10 and the identifier of the receiver 3 are associated and stored in the PC terminal 4, the distance between the sensor device 2 and the receiver 3 can be determined from the signal strength. By estimating, the positional information of the cow 10 can be detected with minimum power consumption without using GPS. Also, by overlapping the receiving areas 3A of a plurality of receivers 3, it is possible to analyze the signal strengths from the plurality of receivers 3 and detect position information more accurately.

Next, a second embodiment of the invention will be described with reference to FIGS. 9 and 10. FIG. The same reference numerals are assigned to the same configurations as in the first embodiment, and the description thereof is omitted. In the first embodiment, the power controller 28 of the sensor device 2 controls the switching means 24 based on the signal from the RTC 28A. , the switching means 24 is controlled in response to .

In the second embodiment, the power control unit 28 includes a comparator that compares the voltage of the power storage unit 26 with a reference voltage, and when the voltage of the power storage unit 26 reaches the discharge threshold of 3.5 [V], the switching means 24 is turned on to supply power to the communication unit 22 and the sensor unit 23, and when the voltage of the electricity storage unit 26 reaches the cutoff threshold of 1.5 [V], the switching means 24 is turned off to turn off the communication unit 22 and the sensor unit 23. Power supply to the sensor unit 23 is cut off. The threshold for switching the switching means 24 can be arbitrarily set according to the capacitance of the storage unit 26, the power generation state of the power generation unit 25, and the like.

Next, sensing by the sensor device 2 will be described with reference to FIGS. 9 and 10. FIG.

Electric power generated by the power generation unit 25 by photovoltaic power generation is stored in the power storage unit 26 via the rectifier 27 . The power control unit 28 determines whether the voltage of the electric storage unit 26 is equal to or higher than the discharge threshold of 3.5 [V] (S11). When the voltage of the storage unit 26 exceeds the discharge threshold (S11: YES), the power control unit 28 turns on the switching means 24 to supply power to the communication unit 22 and the sensor unit 23 (S2, t1).

When power is supplied from the power supply unit 21, the communication unit 22 is initialized (reset) by the control unit 30 starting a program at approximately the same timing as t1. The communication unit 22 consumes a predetermined amount of power at the timing of program initialization. The control unit 30 reads the identifier (ID) assigned to the sensor device 2 and the minimum necessary information from the storage unit 30B (t2). The communication unit 22 and the sensor unit 23 start I2C bus communication (t3), and the control unit 30 transmits a temperature information request to the sensor unit 23 (t4). The sensor unit 23 detects the outside air temperature in response to the temperature information request from the communication unit 22 (t5, S3), and transmits the detected data to the control unit 30 through serial communication.

The control unit 30 converts the detection data received from the sensor unit 23 into digital data in the A/D conversion unit 30A, converts the data into numerical data using a predetermined calculation formula, and stores the data in the storage unit 30B as environmental data. (S4, t6). In this embodiment, since the temperature and humidity can be detected (S6: NO), the control unit 30 again transmits a humidity information request to the sensor unit 23 by I2C bus communication (t7). The sensor unit 23 detects humidity in response to the humidity information request from the communication unit 22 (t8, S3), and transmits the detected detection data to the control unit 30 through serial communication.

The control unit 30 converts the detection data received from the sensor unit 23 into digital data using the A/D conversion unit 30A, converts the data into numerical data using a predetermined calculation formula, and stores the data in the storage unit 30B (S4, t9). The control unit 30 determines that all the data has been acquired (S5: YES), and wirelessly transmits the environmental data of temperature and humidity from the data transmission unit 29 to the receiver 3 (S6, t10). As shown in FIG. 10B, the terminal voltage of the power storage unit 26 decreases stepwise according to the power consumption of the communication unit 22 and the sensor unit 23 . 10(c) and 10(d), standby power is consumed in the communication unit 22 and the sensor unit 23 from t1 to t10, which is the energization time. 22 and the sensor unit 23 will be zero.

When the power control unit 28 determines that the voltage is equal to or less than the cutoff threshold (t11, S17: YES), it turns off the switching means 24 (S8), and waits until the power storage unit 26 is charged again and becomes equal to or greater than the discharge threshold (S11: NO).

The sensor device and sensor system according to the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims.

In the above-described embodiment, the sensor unit 23 can measure at least one of temperature, humidity, illuminance, atmospheric pressure, CO2 concentration, methane gas concentration, and wind force, but the present invention is not limited to this. For example, a 9-axis gyro sensor, a vibration sensor, a touch sensor using a capacitance sensor, a magnetic sensor, a pyroelectric sensor, an ultrasonic sensor, or the like can be used. For example, when the animals to be managed are fish, the water temperature may be detected by a temperature sensor, the water level may be detected by an atmospheric pressure sensor, and the geomagnetism may be detected by a 9-axis sensor to detect the direction of movement. Moreover, when animals in the soil are the target, the moisture content in the soil can be detected by a humidity sensor.

In the above embodiment, the environment data detected by the sensor device 2 is stored in the PC terminal 4 by the receiver 3 via the external network 6, but the data is not limited to this and can be stored on a cloud server. good too. As a result, data detected by the sensor system 1 can be confirmed by a plurality of terminals.

Although the power supply unit 21 and the communication unit 22 do not perform data communication in the above embodiment, the present invention is not limited to this. For example, when the power storage unit 26 is charged, the power supply unit 21 may transmit a pulse signal indicating that charging is completed to the communication unit 22 .

In the above embodiment, the signal from the sensor section 23 is an analog signal and is converted into a digital signal by the A/D conversion section 30A, but it is not limited to this. For example, the signal from the sensor unit 23 may be a digital signal and transmitted to the communication unit 22 by serial communication through the I2C bus. In this case, the digital signal received by the control unit 30 is put into a predetermined calculation formula and converted into numerical data.

1 sensor system 2 sensor device 3 receiver 4 PC terminal 5 mobile terminal 21 power supply unit 22 communication unit 23 sensor unit 24 switching means 25 power generation unit 26 power storage unit 27 rectifier 28 power control unit 29 data transmission unit 30 control unit

Claims (4)

A sensor device that transmits measurement data to an external device by wireless communication,
a power supply unit that supplies electric power;
a plurality of sensors that operate with the power supplied from the power supply unit and sense the surrounding environment;
a storage unit that stores a plurality of environmental data sensed by the plurality of sensors;
a communication unit that operates on the power supplied from the power supply unit and performs one-way communication only for transmission, which transmits the plurality of environmental data in the storage unit to the external device via the wireless communication;
switching means for switching between supplying and cutting off the power to all the sensors and the communication unit provided in the sensor device of the power supply unit;
a time management means for managing time,
The switching means supplies the power to all the sensors and the communication unit provided in the sensor device and cuts off the power at a predetermined timing based on a signal from the time management means. repetition,
When the power is simultaneously supplied from the power supply unit to all the sensors and the communication unit provided in the sensor device by the switching means, the sensor performs sensing and the communication unit is obtained by sensing. transmitting the plurality of environmental data to the external device via the wireless communication;
After the communication unit transmits the environmental data to the external device, the switching means simultaneously cuts off the power from the power supply unit to all the sensors provided in the sensor device and the communication unit;
The sensor device, wherein the communication unit collectively transmits the plurality of environmental data to the external device only once during a period from when the power is supplied from the power supply unit to when the power is cut off . The power supply unit
a power generation unit that generates power from external energy;
a rectifier that rectifies the power generated by the power generation unit;
a power storage unit that stores the power rectified by the rectifier,
2. The sensor device according to claim 1, wherein the power generation unit is at least one of photovoltaic power generation and electromagnetic wave power generation. A sensor device that transmits measurement data to an external device by wireless communication,
supply power,
a power generation unit that generates power from external energy;
a rectifier that rectifies the power generated by the power generation unit;
a power supply unit including a power storage unit that stores the power rectified by the rectifier;
a plurality of sensors that operate with the power supplied from the power supply unit and sense the surrounding environment;
a storage unit that stores a plurality of environmental data sensed by the plurality of sensors;
a communication unit that operates on the power supplied from the power supply unit and performs one-way communication only for transmission, which transmits the plurality of environmental data in the storage unit to the external device via the wireless communication;
switching means for switching between supplying and cutting off the power to all the sensors and the communication unit provided in the sensor device of the power supply unit;
The switching means repeats the supply of the power to all the sensors and the communication unit provided in the sensor device and the cutoff of the power when the voltage of the storage unit reaches a predetermined value. ,
When the power is simultaneously supplied from the power supply unit to all the sensors and the communication unit provided in the sensor device by the switching means, the sensor performs sensing and the communication unit is obtained by sensing. transmitting the plurality of environmental data to the external device via the wireless communication;
After the communication unit transmits the environmental data to the external device, the switching means simultaneously cuts off the power from the power supply unit to all the sensors provided in the sensor device and the communication unit;
The sensor device, wherein the communication unit collectively transmits the plurality of environmental data to the external device only once during a period from when the power is supplied from the power supply unit to when the power is cut off. a sensor device according to any one of claims 1 to 3 attached to livestock;
the external device that receives and stores the environmental data from the communication unit;
a receiver for receiving the environmental data from the sensor device;
the receiver perceives signal strength from the sensor device within a reception area;
The livestock management system, wherein the external device associates and stores an identifier for identifying the receiver that has received the radio wave from the sensor device and the strength of the signal received from the sensor device.

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