KR101960707B1 - IoT System Using Wireless Sensor Network and Gateway - Google Patents

Abstract

More particularly, the present invention proposes a system structure applicable to an industrial field requiring a small-scale / low-cost IoT environment, and suggests an efficient power management method of the sensor device , And a wireless sensor network and a gateway using the same to extend the battery life and eventually extend the life cycle of the system.
The present invention provides a system introduction efficiency applicable to an industrial field requiring a small-scale / low-cost IoT environment.

Description

[0001] The present invention relates to an IoT system using a wireless sensor network and a gateway,

More particularly, the present invention proposes a system structure applicable to an industrial field requiring a small-scale / low-cost IoT environment, and suggests an efficient power management method of the sensor device , And a wireless sensor network and a gateway using the same to extend the battery life and eventually extend the life cycle of the system.

So far, the IoT implementation method has been implemented in a low speed wireless network or a simple IoT relay type in an Ethernet network by using a simple relay network.

As such conventional technology, the home gateway apparatus according to Patent Publication No. 10-2006-0135187 includes a tuner for selecting a communication channel, a cable modem means, a data signal processing means for performing a TCP / IP communication interface, a serial communication interface And RS-232 processing means for providing the RS-232.

However, in 2G or 3G networks, there is a problem that normal communication can not be performed when high-capacity image information of HD, high-speed interface bi-directional communication for sensor interlocking, security function with high CPU occupancy rate and open middleware is applied.

Accordingly, in order to solve such a problem, it is required to perform a high-speed data service by automatically selecting a gigabit communication or an LTE radio network for high-speed data transmission, and automatically recognize the existing communication network in case of a line disconnection, Is becoming an important issue in the field of IoT.

In addition, there is a problem that it is difficult to track the position of a wired vehicle such as an ATM device when the vehicle is stolen. In addition, a weight information sensor such as a waste transportation vehicle is used to track the real- have.

Since the sensor specifications for the Internet (IoT) implementation are required from conventional analog to video image streaming, there is a problem that smooth communication can not be achieved with existing 2G or 3G networks.

To this end, the need for high-speed wireless communication and Gigabit Ethernet-class gateway systems capable of HD video service has increased.

In order to interoperate with sensors, a high-end gateway system is required not only for existing communication network interfaces but also for security applications requiring high-speed data service bi-directional communication and CPU occupation ratio, and various object internet supporting open middleware.

In addition, to provide high-speed data service, it is required to develop a system having a GMS (Gateway Management Server) function considering LTE interface, bi-directional communication for supporting Giga LAN and Wi-Fi based gateway, and managing the Internet.

In order to increase the service reliability of these networks, stable network operation is required in any environment.

On the other hand, various IoT technologies are being studied throughout the industry and they are trying to apply these technologies effectively.

However, most of the work on IoT relies on the complex architecture of sensor devices, gateways, network servers, and application servers.

Of course, they have obvious advantages in terms of flexibility and scalability.

The problem is that such a configuration is relatively complicated, resulting in implementation difficulties and unnecessary costs, resulting in a hindrance to the introduction of IoT in industries requiring a small network environment.

For example, IoT (Internet of Things) refers to technology that connects sensors and communication functions to various objects and connects them to the Internet.

Here, things become a variety of embedded systems such as home appliances, mobile devices, smart devices, healthcare equipment, and wearable computers.

In addition, the sensor information of various objects can be acquired and controlled from a remotely located server through a communication function.

IoT is subordinate to LPWAN (Low Power Wide Area Network) which is a broad concept, and LPWAN technology is mainly led by three standardization groups.

The first is SIGFOX, which is the first in the world to define the concept of LPWAN (2008) and to expand its power based on its monopoly position.

SIGFOX uses UNB (Ultra Narrow Band) as a wireless technology for IoT, and supports coverage up to 50km.

The second is the LoRa (Long Range) Alliance, led by SemTech and IBM Research.

LoRa is a wireless technology that uses simplified code division multiple access (CDMA) with less interference and noise immunity.

Compared to SIGFOX, it has wide coverage (up to 80km).

Finally, WEIGHTLESS is an open standard.

WEIGHTLESS is characterized by using a combination of Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) in a multiple access scheme.

A typical common feature of the above technologies is that the system uses an Industrial Scientific and Medical (ISM) band as a frequency band and a system as shown in FIG.

The configuration as shown in FIG. 1 ensures flexibility and scalability to continuously add a number of sensor devices and gateways (G / W).

However, in a field where a low-cost / small-scale IoT environment is constructed and utilized by itself, it may not be suitable due to the complexity of the structure, installation cost, and difficulty in operation.

Accordingly, the present invention proposes a system structure that can be applied to an industrial field requiring a small-scale / low-cost IoT environment, and suggests an efficient power management method of the sensor device, thereby extending battery life and ultimately increasing the life cycle of the system .

Korean Patent Publication No. 10-2006-0135187

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art,

It is an object of the present invention to provide a system applicable to an industrial field requiring a small-scale / low-cost IoT environment, and propose an efficient power management method of a sensor device, thereby prolonging a battery life and ultimately extending a life cycle of the system .

According to an aspect of the present invention, there is provided an i-thi system using a wireless sensor network and a gateway according to an embodiment of the present invention,

Acquires temperature and humidity information from the temperature and humidity sensor 10, acquires illuminance information from the illuminance sensor 20, acquires battery voltage from the battery 30, and acquires temperature and humidity information, illuminance information, battery voltage information (100) for providing temporary data including the temporary data to the sensor data transmitting means (200) and acquiring status information on whether all the temporary data has been transmitted from the sensor data transmitting means (200)

Sensor data transmitting means (200) for temporarily storing the temporary data provided from the sensor data acquiring means (100), transmitting the temporary data to the gateway, and providing status information about whether or not all the temporary data has been transmitted to the sensor data acquiring means, A sensor device 1000 comprising:

A gateway central controller 2100 for determining whether the temporary data provided by the sensor device is normal and removing the checksum byte and providing temporary data to the bridge unit;

A bridge unit 2200 for connecting communication between the gateway central control unit and the wireless communication unit and providing provisional data provided by the gateway central control unit to the wireless communication unit;

And a wireless communication unit 2300 for transmitting the provisional data provided by the bridge unit to the sensor data management server 3000. The gateway 2000 comprises:

And a sensor data management server 3000 for acquiring temporary data transmitted from the gateway and periodically storing the obtained temporary data in the power management database 3100.

In addition, the sensor data acquisition means (100)

A temperature / humidity obtaining unit 110 for obtaining temperature and humidity information from the temperature / humidity sensor 10;

An illuminance acquiring unit 120 for acquiring illuminance information from the illuminance sensor 20;

A battery voltage obtaining unit 130 for obtaining a battery voltage from the battery 30;

A memory unit 140 for storing packet data;

A sensing data collecting unit 150 for acquiring the temperature and humidity information, the illuminance information, and the battery voltage information and providing the sensing data to the sensing data obtaining unit 210 of the sensor data transmitting means 200;

Acquiring status information for acquiring status information about whether all the temporary data stored in the temporary data storage unit 230 provided by the sensor data transmitting unit 200 has been transmitted or whether new temperature and humidity information, illuminance information, and battery voltage information are acquired (160); and

The control unit 110 controls the temperature and humidity acquisition unit 110, the illumination acquisition unit 120, the battery voltage acquisition unit 130, the memory unit 140, the sensing data collection unit 150, And a sensor central control unit (170).

Further, the sensor data transmitting means (200)

A sensing data acquisition unit 210 for receiving temperature and humidity information, illumination information, and battery voltage information provided from the sensing data collection unit 150 of the sensor data acquisition unit 100 and temporarily storing the received temperature and humidity information, );Wow

A temporary data storage unit 230 for temporarily storing temperature and humidity information, illumination information, and battery voltage information provided by the sensing data acquisition unit;

State information for providing the status information on whether temperature and humidity information, roughness information, and temporary data, which are battery voltage information, all stored in the temporary data storage unit are transmitted to the status information obtaining unit 160 of the sensor data obtaining unit 100, A check unit 220;

And a sensing data transmission unit 240 for transmitting temporary data, which is temperature and humidity information, illumination information, and battery voltage information, stored in the temporary data storage unit, to the gateway 2000.

In addition, the sensor data management server (3000)

The sensor device controls to transmit the temporary data of the sensor at a predetermined time period and transmits the sleep interval control information to the gateway for the remaining time excluding the transmission time to operate in the sleep mode, A control processing unit 3200;

And a battery power management unit 3300 for estimating a replacement time point of the battery by referring to the battery voltage information included in the temporary data transmitted from the sensor device.

At this time, in the gateway 2000,

The temporary data format to be transmitted is,

Packet data, sensor data, and power data.

In addition, the sensing data transmission unit 240 of the sensor data transmission unit 200 provides a power table for setting the output power [dBm] in eight steps for RF output power management, RSSI is provided,

The gateway central control unit 2100 in the gateway performs adaptive power control for adjusting the RF Power Table Level of the sensor device according to the reception intensity.

As described above, the iOuti system using the wireless sensor network and the gateway of the present invention provides a system introduction efficiency applicable to an industrial field requiring a small-scale / low-cost IoT environment.

In addition, it provides an efficient power management method of the sensor device, thereby extending the life of the battery and ultimately providing the effect of extending the life cycle of the system.

1 is a schematic diagram showing a configuration of a conventional LPWAN system.
2 is an overall configuration diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.
3 is an overall block diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.
4 is an overall block diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating an example of a transmission data format of a sensor device of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention. FIG. 6 is a field detail view of sensor device transmission data, 9 is an exemplary view of an initial RF setting value of the sensor data transmitting means, FIG. 10 is an example of a sleep interval control for power management, and FIG. FIG. 12 is an exemplary graph of an optimal power table setting value, FIG. 13 is an example of RSSI step setting according to reception intensity, FIG. 14 is a sensor device adaptive power control graph, Fig. 15 is a power consumption graph according to the adaptive power control, Fig. 16 is a voltage distribution circuit diagram, Fig. FIG. 18 is a graph showing an execution time and consumed current for each step. FIG.

The iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention,

Acquires temperature and humidity information from the temperature and humidity sensor 10, acquires illuminance information from the illuminance sensor 20, acquires battery voltage from the battery 30, and acquires temperature and humidity information, illuminance information, battery voltage information (100) for providing temporary data including the temporary data to the sensor data transmitting means (200) and acquiring status information on whether all the temporary data has been transmitted from the sensor data transmitting means (200)

Sensor data transmitting means (200) for temporarily storing the temporary data provided from the sensor data acquiring means (100), transmitting the temporary data to the gateway, and providing status information about whether or not all the temporary data has been transmitted to the sensor data acquiring means, A sensor device 1000 comprising:

A gateway central controller 2100 for determining whether the temporary data provided by the sensor device is normal and removing the checksum byte and providing temporary data to the bridge unit;

A bridge unit 2200 for connecting communication between the gateway central control unit and the wireless communication unit and providing provisional data provided by the gateway central control unit to the wireless communication unit;

And a wireless communication unit 2300 for transmitting the provisional data provided by the bridge unit to the sensor data management server 3000. The gateway 2000 comprises:

And a sensor data management server 3000 for acquiring temporary data transmitted from the gateway and periodically storing the obtained temporary data in the power management database 3100.

In addition, the sensor data acquisition means (100)

A temperature / humidity obtaining unit 110 for obtaining temperature and humidity information from the temperature / humidity sensor 10;

An illuminance acquiring unit 120 for acquiring illuminance information from the illuminance sensor 20;

A battery voltage obtaining unit 130 for obtaining a battery voltage from the battery 30;

A memory unit 140 for storing packet data;

A sensing data collecting unit 150 for acquiring the temperature and humidity information, the illuminance information, and the battery voltage information and providing the sensing data to the sensing data obtaining unit 210 of the sensor data transmitting means 200;

Acquiring status information for acquiring status information about whether all the temporary data stored in the temporary data storage unit 230 provided by the sensor data transmitting unit 200 has been transmitted or whether new temperature and humidity information, illuminance information, and battery voltage information are acquired (160); and

The control unit 110 controls the temperature and humidity acquisition unit 110, the illumination acquisition unit 120, the battery voltage acquisition unit 130, the memory unit 140, the sensing data collection unit 150, And a sensor central control unit (170).

Further, the sensor data transmitting means (200)

A sensing data acquisition unit 210 for receiving temperature and humidity information, illumination information, and battery voltage information provided from the sensing data collection unit 150 of the sensor data acquisition unit 100 and temporarily storing the received temperature and humidity information, );Wow

A temporary data storage unit 230 for temporarily storing temperature and humidity information, illumination information, and battery voltage information provided by the sensing data acquisition unit;

State information for providing the status information on whether temperature and humidity information, roughness information, and temporary data, which are battery voltage information, all stored in the temporary data storage unit are transmitted to the status information obtaining unit 160 of the sensor data obtaining unit 100, A check unit 220;

And a sensing data transmission unit 240 for transmitting temporary data, which is temperature and humidity information, illumination information, and battery voltage information, stored in the temporary data storage unit, to the gateway 2000.

In addition, the sensor data management server (3000)

The sensor device controls to transmit the temporary data of the sensor at a predetermined time period and transmits the sleep interval control information to the gateway for the remaining time excluding the transmission time to operate in the sleep mode, A control processing unit 3200;

And a battery power management unit 3300 for estimating a replacement time point of the battery by referring to the battery voltage information included in the temporary data transmitted from the sensor device.

At this time, the sensor data acquisition means 100 of the sensor device 1000,

And the transmission output is divided into a plurality of stages on the basis of 0 dBm which is a point where the consumption current abruptly rises according to the transmission output.

At this time, the gateway 2000,

In order to adaptively control the transmission power of the sensor device through communication with the sensor device, the reception intensity region is divided into five levels, and a critical region is set based on the reception intensity corresponding to 0 dBm, The transmission output of the sensor device is incremented by one step and the transmission output of the sensor device is decreased by one step when the reception intensity is equal to or more than the critical region.

At this time, the temporary data format to be transmitted to the gateway 2000,

Packet data, sensor data, and power data.

In addition, the sensing data transmission unit 240 of the sensor data transmission unit 200 provides a power table for setting the output power [dBm] in eight steps for RF output power management, RSSI is provided,

The gateway central control unit 2100 in the gateway performs adaptive power control for adjusting the RF Power Table Level of the sensor device according to the reception intensity.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The ioTi, which is generally described in the present invention, is referred to as " IoT "

2 is an overall configuration diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.

As shown in FIG. 2, the system of the present invention largely comprises a plurality of sensor devices 1000, a gateway 2000, and a sensor data management server 3000.

At this time, the general LPWAN system has a separate network server for managing the gateway in order to facilitate the joining or termination of the sensor device.

However, the system of the present invention can provide a merit that small-scale and low-cost components can be used through direct connection between the gateway 2000 and the sensor data management server 3000 without a network server.

Meanwhile, the sensor device 1000 and the gateway 2000 preferably communicate with RF433 wireless communication, and the gateway and the sensor data management server 3000 use Wi-Fi wireless communication, Connected to the public network.

3 is an overall block diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.

As shown in FIG. 3, the sensor device 1000 acquires the temperature, the humidity, the illuminance, and the battery voltage level supplied to the device.

At this time, the sensor device 1000 includes the sensor data acquisition means 100 and the sensor data transmission means 200.

The sensor data acquisition means 100 acquires temperature and humidity information from the temperature / humidity sensor 10, acquires illumination information from the illumination sensor 20, acquires battery voltage from the battery 30, The sensor data transmitting means 200 provides the temporary data including the humidity information, the illuminance information, and the battery voltage information to the sensor data transmitting means 200 and acquires status information on whether all of the temporary data has been transmitted from the sensor data transmitting means 200 do.

The sensor data transmitting means 200 temporarily stores the temporary data provided from the sensor data acquiring means 100, transmits the temporary data to the gateway, and transmits status information about whether or not all of the temporary data has been transmitted to the sensor data acquiring means As shown in FIG.

In order to perform the above function, the sensor data acquisition means 100 acquires,

A temperature / humidity obtaining unit 110 for obtaining temperature and humidity information from the temperature / humidity sensor 10;

An illuminance acquiring unit 120 for acquiring illuminance information from the illuminance sensor 20;

A battery voltage obtaining unit 130 for obtaining a battery voltage from the battery 30;

A memory unit 140 for storing packet data;

A sensing data collecting unit 150 for acquiring the temperature and humidity information, the illuminance information, and the battery voltage information and providing the sensing data to the sensing data obtaining unit 210 of the sensor data transmitting means 200;

Acquiring status information for acquiring status information about whether all the temporary data stored in the temporary data storage unit 230 provided by the sensor data transmitting unit 200 has been transmitted or whether new temperature and humidity information, illuminance information, and battery voltage information are acquired (160); and

The control unit 110 controls the temperature and humidity acquisition unit 110, the illumination acquisition unit 120, the battery voltage acquisition unit 130, the memory unit 140, the sensing data collection unit 150, And a sensor central control unit (170).

The temperature and humidity information is acquired from the temperature and humidity sensor 10 through the temperature and humidity acquisition unit 110 and the illumination information is acquired from the illumination sensor 20 through the illumination acquisition unit 120, And acquires the battery voltage from the battery 30 through the battery charger 130,

The sensing data collecting unit 150 acquires the temperature and humidity information, the illuminance information, and the battery voltage information and provides the sensed data to the sensing data obtaining unit 210 of the sensor data transmitting unit 200.

In this case, the memory unit 140 stores packet data.

The state information acquisition unit 160 determines whether the temporary data stored in the temporary data storage unit 230 provided by the sensor data transmission unit 200 has been transmitted or acquired new temperature and humidity information, And obtains the status information about the user.

That is, if the sensing data collecting unit 150 provides temporary data including temperature and humidity information, roughness information, and battery voltage information to the sensing data obtaining unit 210 of the sensor data transmitting unit 200, Temporarily stores it in the temporary data storage unit 230 provided by the means 200, modulates it to a frequency of 433 MHz, and transmits it to the gateway.

In this process, the status information check unit 220 of the sensor data transmitting unit 200 provides the status information obtaining unit 160 with status information indicating whether all the temporary data in the temporary data storing unit has been transmitted.

At this time, the temporary data format transmitted to the gateway 2000 includes packet data, sensor data, and power data.

5, the information transmitted from the sensor device 1000 has a total length of 23 bytes and is divided into three types (packet data indicating information of the packet itself, sensor data having sensor information , And power data required for power management).

Each field of the packet is described in detail in FIG.

 That is, the packet data includes Packet ID (RF433 Transmission Packet ID), F / W version (firmware version information), Sensor Device ID (Sensor Device ID), Gateway ID (Gateway ID), Sequence Number .

The sensor data includes payload type (payload type classification (data or command)), payload length (payload length (18 bytes)), temperature (temperature data), humidity (humidity data), and CDS .

The power data includes Sleep Interval, RF Power Level, Battery Power Level, and Checksum (the checksum information of sensor data and power data) have.

Packet ID, F / W ver., Sensor Device ID, and Gateway ID of the packet data are pre-stored in the memory unit 140.

When the entire packet is transmitted, it is read from the memory unit 140 and transmitted. In the case of sensor data, data is acquired from each sensor at the transmission time and transmitted.

On the other hand, the sensor data transmitting means (200)

A sensing data acquisition unit 210 for receiving temperature and humidity information, illumination information, and battery voltage information provided from the sensing data collection unit 150 of the sensor data acquisition unit 100 and temporarily storing the received temperature and humidity information, );Wow

A temporary data storage unit 230 for temporarily storing temperature and humidity information, illumination information, and battery voltage information provided by the sensing data acquisition unit;

State information for providing the status information on whether temperature and humidity information, roughness information, and temporary data, which are battery voltage information, all stored in the temporary data storage unit are transmitted to the status information obtaining unit 160 of the sensor data obtaining unit 100, A check unit 220;

And a sensing data transmission unit 240 for transmitting temporary data, which is temperature and humidity information, illumination information, and battery voltage information, stored in the temporary data storage unit, to the gateway 2000.

That is, the sensing data acquiring unit 210 receives the temperature and humidity information, illumination information, and battery voltage information provided from the sensing data collecting unit 150 of the sensor data acquiring unit 100, Respectively.

The temporary data storage unit 230 temporarily stores temperature and humidity information, illumination information, and battery voltage information provided by the sensing data acquisition unit.

The status information check unit 220 transmits status information about whether temperature and humidity information, roughness information, and temporary data, which are battery voltage information, stored in the temporary data storage unit are all transmitted, to the status information obtaining unit 160 ).

The sensing data transmission unit 240 transmits temporary data, which is temperature and humidity information, illumination information, and battery voltage information stored in the temporary data storage unit, to the gateway 2000.

On the other hand, as shown in FIG. 2, in the gateway 2000 of the present invention,

A gateway central controller 2100 for determining whether the temporary data provided by the sensor device is normal and removing the checksum byte and providing temporary data to the bridge unit;

A bridge unit 2200 for connecting communication between the gateway central control unit and the wireless communication unit and providing provisional data provided by the gateway central control unit to the wireless communication unit;

And a wireless communication unit 2300 for transmitting the provisional data provided by the bridge unit to the sensor data management server 3000.

The gateway 2000 is an open hardware-based platform as one of solutions for IoT.

A configuration in which a wireless communication function is included so that an Internet connection can be established to a platform capable of acquiring information through sensor devices.

Accordingly, the gateway disclosed in the present invention constitutes a shield device for demodulating a signal transmitted at 433 MHz in a sensor device, and a gateway central control unit for converting received data into packets transmittable through a public network.

On the other hand, the wireless communication unit 2300 preferably uses OpenWRT, which is optimized for the IoT system as a Linux environment, and OpenWRT is a Linux-based open source operating system for a wireless LAN router.

When the data is received by RF433, the sensor data transmitting means notifies the state information obtaining unit 160 of the sensor data obtaining means 160 that new data has been received through the state information checking unit, and the sensing data collecting unit 150 ) To fetch the data temporarily stored in the temporary data storage unit.

The received data is analyzed by the sensor central control unit 170 and then responded to the sensor device in the format shown in FIG.

The packet data in the response data format is the same as in Fig. 6, and Checksum is applied only to the data after the Response Type in Control Data.

FIG. 8 illustrates success / failure responses for each field of the control data of the gateway.

That is, the common includes fields of Payload Type (Payload Type received from the sensor device), Payload Length (Payload Length received from the sensor device), and Response Type (ACK in case of success and NAK in case of error).

Success includes Sleep Interval (sensor device sleep time transmitted from the server) and RF Power Level (RF Power Level to be used in the sensor device).

The error includes a field of Error Code (predefined error cause code if Response Type is NAK) and Padding (0x00).

When the data received from the sensor device in the gateway is analyzed as normal, 2 bytes of Checksum in FIG. 5 are removed, and 1 byte of Receive Signal Strength Indicator (RSSI) as a reception strength is added and transmitted to the gateway central control unit 2100 through the UART .

The data transmitted to the gateway central control unit 2100 is transmitted to the wireless communication unit through the bridge unit, and the wireless communication unit connects to the Wi-Fi wireless access point (AP) and finally transmits the data to the sensor data management server 3000.

For example, data transmission from the gateway to the sensor data management server 3000 is performed in the POST manner by calling the Linux run command cURL in the gateway central control unit 2100.

If the received data is analyzed as an error, data is not transmitted to the wireless communication unit 2300, NAK in the Response Type of Control Data, error code in Error Code, and 0x00 in the Padding field are filled in the response data format, Lt; / RTI >

Then, the sensor device stores the error code in the memory unit 140 and is used for error cause analysis in the future.

4 is an overall block diagram of an iOuti system using a wireless sensor network and a gateway according to an embodiment of the present invention.

As shown in Fig. 4, the sensor data management server 3000,

A power management database 3100 that acquires and periodically stores temporary data transmitted from the gateway;

The sensor device controls to transmit the temporary data of the sensor at a predetermined time period and transmits the sleep interval control information to the gateway for the remaining time excluding the transmission time to operate in the sleep mode, A control processing unit 3200;

And a battery power management unit 3300 for estimating the replacement time of the battery with reference to the battery voltage information included in the temporary data transmitted from the sensor device.

The sensor data management server 3000 can be implemented by installing Apache for a static web page, PHP for a dynamic web page, and MySQL for managing a power management database 3100 in the form of a web server.

For example, information transmitted in a POST manner from the gateway using the HTTP protocol is periodically stored in a specific table of the power management database 3100 which is interpreted in the PHP page and defined in advance.

The information stored in the power management database 3100 is utilized to establish an efficient power management strategy.

In the wireless sensor network, since the sensor device 1000 uses a battery, efficient power management is indispensable, and a lot of research has been conducted.

However, most of the studies are theoretical.

In the present invention, two power control methods and one power management method for a sensor device that can be practically applied and implemented will be described.

9 shows RF initial setting values of the sensor data transmitting means used in the embodiment.

The RF setting items include RF Frequency, RF Output Power, Rx Filter Bandwidth, Deviation, Data Rate, Modulation, Channel Spacing, and Channel Number.

The initial setting value of RF frequency is 433 MHz, the initial setting value of RF output power is 0 dBm, the initial setting value of Rx Filter Bandwidth is 541.666667 kHz, the initial setting value of Deviation is 127 kHz, The setting value is 250 kBaud. The initial setting value of modulation is GFSK, the initial setting value of channel spacing is 200 kHz, and the initial value of channel number is 0.

The sleep interval control processor 3200 controls the sensor device to transmit the temporary data of the sensor at a predetermined time period. The sleep interval control processor 3200 transmits the sleep interval control information to the gateway so as to operate in the sleep mode for the remaining time except for the transmission time, To the sensor device.

For example, in an IoT environment, the sensor device reports sensor information to the sensor data management server at a predetermined time period.

Except for the reporting interval, the remaining time is set to sleep mode to minimize power consumption.

Therefore, if the sensor data management server variably operates the reporting period, the power can be reduced accordingly.

10 shows a method of applying a reporting period stored in a server to a sensor device.

The sensor central controller 170 of the sensor device controls five sleep modes (Idle, ADC Noise Reduction, Power-down, Power-save, Standby).

It is most preferable to select the power-down that can reduce the power most and to use the watchdog timer with the wake-up method.

Meanwhile, according to the preferred embodiment, if the watchdog timer is fixed at 8 seconds, for example, the sensor data management server 3000 can be configured to receive sensor data at a multiple of 8 times.

 The procedure for controlling the sleep interval of the sleep interval control processor 3200 is as follows.

1) The sensor device 1000 transmits data to the gateway 2000, and the gateway normally responds to the sensor device.

2) The gateway transmits sensor information to the sensor data management server. At this time, the gateway receives and stores the sleep interval stored in the power management database from the sensor data management server.

To this end, according to a further aspect, the power management database 3100 may store sleep interval information.

3) When the next sensor information is received, the gateway sends the sleep interval received from the sensor data management server to the sensor device in response.

4) The sensor device saves the sleep interval received from the gateway in the memory and enters sleep mode.

Then every 8 seconds Watchdog Timer wakes up every time it is expired to check Sleep Interval.

5) If the same time as the newly set Sleep Interval has elapsed, repeat from step 1).

If the sleep interval received from the sensor data management server is 16 seconds, the sensor device performs the wake-up process twice after sleep and transmits the sensor data to the gateway.

The above procedure can control the Sleep Interval and reduce the power consumption.

11 shows the operation sequence of the sensor device sleep mode and wake-up for about 200 seconds.

As shown in FIG. 11, when the sensor device consumes about 8 mA of power at the wake-up and turns on the power of the sensor data transmitting means 200 to activate the RF function, the sensor device consumes about 28 mA of power.

When the sensor data transmitting means 200 is powered off and enters the sleep mode of the sensor device, only the power of about 0.9 mA is finally used, so that efficient power reduction can be achieved.

Meanwhile, the sensing data transmission unit 240 of the sensor data transmission unit 200 provides a power table for setting the output power [dBm] in eight steps for RF output power management.

Also, it provides RSSI which can know the signal strength when receiving RF signal.

Accordingly, the gateway central control unit 2100 in the gateway performs adaptive power control to adjust the RF Power Table Level of the sensor device according to the reception intensity.

When receiving the information from the sensor device at the gateway, the received signal strength is measured. If the measured signal strength is smaller than the predetermined threshold, the power level is increased. If the measured signal strength is larger than the predetermined threshold, the RF power level After setting a value in the field, the value is transmitted to the sensor device.

At the time of response, the gateway sets its transmission output power to the same level as the power level responding to the sensor device.

This process is repeatedly performed for all the sensor devices connected to the gateway, thereby performing adaptive power control.

The RF output power of the sensor data transmitting means 200 is -30 dBm to 10 dBm, and the consumption current according to the RF output power is shown in FIG.

FIG. 12 shows that power consumption increases sharply at an output of RF power of 0 dBm or more.

Therefore, the initial power level is set to 0 dBm in consideration of battery life and communication quality.

When the data rate is 250 kBaud, the RSSI is measured from -110 dBm to -10 dBm.

In the gateway, as shown in FIG. 13, it is divided into 5 levels and the threshold is set to 4 levels.

Accordingly, when the RSSI is equal to or less than four, the power level of the sensor device is controlled by increasing the power level by one level according to FIG. 12 and decreasing the level by one level when the RSSI is four or more.

When the adaptive power control as described above is performed, the RSSI is repeatedly measured in the third and fourth steps, so that efficient power management is possible while maintaining the optimum communication quality.

The sensor data acquisition means (100) of the sensor device (1000)

Preferably, as shown in FIG. 12, the transmission output is divided into a plurality of stages on the basis of 0 dBm, which is a point where the consumed current abruptly rises according to the transmission output.

In the gateway 2000 of the present invention,

Preferably, as shown in FIG. 13, in order to adaptively control the transmission power of the sensor device through communication with the sensor device, the reception intensity region is divided into five levels, and based on the reception intensity corresponding to 0 dBm The transmission output of the sensor device is incremented by one step and the transmission output of the sensor device is decreased by one step when the reception intensity is greater than or equal to the critical region, do.

FIG. 14 shows a waveform in which the sensor device controls the RF output power through adaptive power control, and FIG. 15 shows the waveform of the consumed current varying according to the varying RF output power.

FIG. 15 shows a tendency that power consumed according to the RF output power of FIG. 14 increases or decreases.

Therefore, since the power saving by the adaptive power control is performed in the decreasing part, efficient power management is possible.

Meanwhile, the battery power management unit 3300 performs a function of estimating the replacement time of the battery by referring to the battery voltage information included in the temporary data transmitted from the sensor device.

The battery used in the IoT environment is not charged with consumable parts, and only the discharging is continued, so replacement is required at an appropriate time.

In the data format of FIG. 5, since the battery voltage measured by the ADC (analog-digital converter) is transmitted to the battery power level field, the sensor data management server can estimate the replacement time based on the battery voltage.

The battery residual voltage measurement is performed through the battery voltage obtaining unit 130, for example, the set voltage reference is 1.1V.

Therefore, the measurable voltage level through the battery voltage obtaining unit 130 is 1.1 V or less and is measured through a voltage distribution circuit using a resistor as shown in FIG.

Since the battery voltage obtaining section is calculated as V_IN (input voltage) XR1 / (R1 + R2), it is measured as 1.1V when the input voltage is 3.3V.

FIG. 17 shows a state in which the measured battery voltage is polynomially fitted in a first order polynomial.

As a result of numerous experiments, the sensor device can communicate with the gateway by acquiring the sensor data normally until the battery voltage reaches 2.55V.

Therefore, when the battery voltage reaches 2.55V, the sensor data management server may be configured to give an alarm to the operator to replace the battery of the sensor device.

That is, the battery power management unit 3300 estimates the replacement time of the battery, and sends an alarm signal to the administrator terminal when it is determined that the battery is replaced.

In addition, when RF output power is applied to 0 dBm, the time and consumed current in each step are measured as shown in FIG.

When the IoT system of the present invention is operated based on FIG. 18, 62.5 times is performed for 1 hour, and the current consumption is calculated based on the 62.5 times.

1.2285mA [(0.97mA X 3500s) + (8mA X 75s) + (8.2mA X 12.5s) + (26 X 12.5s)] / 3600s

1.2285mA

The capacity of a typical AA battery is 2850 mAh and the operating time is calculated as follows.

2320 hour/24 hour

96일2850mAh / 1.2285mA

2320 hour / 24 hour

96 days

Accordingly, if the power is managed as described above, the battery can be used for about three months without replacing the battery. If the sleep interval is longer, the battery can be used for a longer period of time.

In addition, since the battery can be replaced when necessary, it is possible to maintain continuous IoT communication.

As described above, the iOuti system using the wireless sensor network and the gateway of the present invention provides a system introduction efficiency applicable to an industrial field requiring a small-scale / low-cost IoT environment.

It will be appreciated by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is to be understood, therefore, that the embodiments described above are to be considered in all respects as illustrative and not restrictive.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

1000: Sensor device
2000: Gateway
3000: Sensor data management server

Claims (7)

In an i-thi system using a wireless sensor network and a gateway,
Acquires temperature and humidity information from the temperature and humidity sensor 10, acquires illuminance information from the illuminance sensor 20, acquires battery voltage from the battery 30, and acquires temperature and humidity information, illuminance information, battery voltage information (100) for providing temporary data including the temporary data to the sensor data transmitting means (200) and acquiring status information on whether all the temporary data has been transmitted from the sensor data transmitting means (200)
Sensor data transmitting means (200) for temporarily storing the temporary data provided from the sensor data acquiring means (100), transmitting the temporary data to the gateway, and providing status information about whether or not all the temporary data has been transmitted to the sensor data acquiring means, A sensor device 1000 comprising:

A gateway central controller 2100 for determining whether the temporary data provided by the sensor device is normal and removing the checksum byte and providing temporary data to the bridge unit;
A bridge unit 2200 for connecting communication between the gateway central control unit and the wireless communication unit and providing provisional data provided by the gateway central control unit to the wireless communication unit;
And a wireless communication unit 2300 for transmitting the provisional data provided by the bridge unit to the sensor data management server 3000. The gateway 2000 comprises:

And a sensor data management server 3000 for acquiring temporary data transmitted from the gateway and periodically storing the acquired temporary data in the power management database 3100,
The sensor data management server (3000)
The sensor device controls to transmit the temporary data of the sensor at a predetermined time period and transmits the sleep interval control information to the gateway for the remaining time excluding the transmission time to operate in the sleep mode, A control processing unit 3200;
And a battery power management unit (3300) for estimating a replacement time point of the battery by referring to the battery voltage information included in the temporary data transmitted from the sensor device. system.
The method according to claim 1,
The sensor data acquisition means (100)
A temperature / humidity obtaining unit 110 for obtaining temperature and humidity information from the temperature / humidity sensor 10;
An illuminance acquiring unit 120 for acquiring illuminance information from the illuminance sensor 20;
A battery voltage obtaining unit 130 for obtaining a battery voltage from the battery 30;
A memory unit 140 for storing packet data;
A sensing data collecting unit 150 for acquiring the temperature and humidity information, the illuminance information, and the battery voltage information and providing the sensing data to the sensing data obtaining unit 210 of the sensor data transmitting means 200;
Acquiring status information for acquiring status information about whether all the temporary data stored in the temporary data storage unit 230 provided by the sensor data transmitting unit 200 has been transmitted or whether new temperature and humidity information, illuminance information, and battery voltage information are acquired (160); and
The control unit 110 controls the temperature and humidity acquisition unit 110, the illumination acquisition unit 120, the battery voltage acquisition unit 130, the memory unit 140, the sensing data collection unit 150, And a sensor central controller 170. The wireless sensor network and the gateway using the wireless sensor network.
The method according to claim 1,
The sensor data transmitting means (200)
A sensing data acquisition unit 210 for receiving temperature and humidity information, illumination information, and battery voltage information provided from the sensing data collection unit 150 of the sensor data acquisition unit 100 and temporarily storing the received temperature and humidity information, );Wow
A temporary data storage unit 230 for temporarily storing temperature and humidity information, illumination information, and battery voltage information provided by the sensing data acquisition unit;
State information for providing the status information on whether temperature and humidity information, roughness information, and temporary data, which are battery voltage information, all stored in the temporary data storage unit are transmitted to the status information obtaining unit 160 of the sensor data obtaining unit 100, A check unit 220;
And a sensing data transmitter (240) for transmitting temporary data, which is temperature and humidity information, illumination information, and battery voltage information, stored in the temporary data storage, to the gateway (2000) IOuti system using gateway.
delete The method according to claim 1,
The sensor data acquisition means 100 of the sensor device 1000,
And the transmission output is divided into a plurality of stages based on 0 dBm, which is a point where the consumption current is rapidly increased according to the transmission power. The method according to claim 1,
The gateway 2000,
In order to adaptively control the transmission power of the sensor device through communication with the sensor device,
A threshold area is set based on a reception intensity corresponding to 0 dBm, and when the reception intensity is less than or equal to the critical area, the transmission output of the sensor device is incremented by one step, And the transmission output of the sensor device is decreased by one step in the case of the critical region or more.
The method according to claim 1,
With the gateway 2000,
The temporary data format to be transmitted is,
Packet data, sensor data, and power data.

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