KR20180083074A - Monitoring device for streetlights - Google Patents

Abstract

The present invention relates to a monitoring device for a streetlamp, which is placed in each streetlamp to monitor states of the streetlamp and transmits monitoring information to a monitoring computer which monitors streetlamps. The monitoring device of the present invention comprises one or more sensors which measure information including positions, currents, voltages, illumination, temperatures, and humidity; a control module which receives measured data from the sensors and generates monitoring information able to be transmitted; and a communication module which transmits information from the control module. The communication module of the monitoring device is configured by a low power wireless broadband communication module and transmits the monitoring information to a monitoring computer through a low power communication network.

Description

{MONITORING DEVICE FOR STREETLIGHTS}

The present invention relates to a monitoring apparatus for a street lamp, and more particularly, to an apparatus for monitoring information of a street lamp by monitoring the state of the street lamp by being disposed in each street lamp.

Street lamps can be used to identify roads, objects, or passengers when pedestrians or vehicles pass by illuminating roads and other lights at night, thereby preventing traffic accidents and crimes, ensuring the safety of road users, It can be used.

Streetlights are installed in large cities and downtown areas with many lights from buildings, but they are installed in places where there are few buildings or various social infrastructures because they have to be installed in a place where there is little traffic or buildings, It takes a lot of time and money to manage, maintain and repair.

It is difficult and often expensive to check whether the streetlight is operating normally because the manager has to travel long distances in order to manage the streetlights that are located far away from the manager's location to maintain and repair the streetlights.

Recently, an intelligent streetlight system has been developed which monitors the operation status of streetlights and notifies the manager of the operation of the streetlights disposed at the remote or wide area. However, since the efficiency is low compared to the high cost, to be.

There is a smart streetlight system of 'EZLuz system' or 'CITY SENSE' of 'Wisys Technologies' as a technology to manage streetlight efficiently. In these technologies, data collected from a streetlight is transmitted to a server of an administrator using ZigBee communication, radio frequency (RF) communication, or mobile communication network.

However, since communication modules such as ZigBee and RF technology are priced at about 200,000 won or more per unit, it is very difficult to install such a communication module for each streetlight. Moreover, this type of communication module has a lower efficiency than a high construction cost because the number of devices that can be connected to one server at the same time is also small. Furthermore, when using a mobile communication network, it is difficult to cover not only the price of a communication module but also a high communication cost.

Moreover, there is also a problem that mountainous areas and island areas are often not equipped with infrastructure for these types of communication.

Japanese Patent Application Laid-Open No. 10-2015-0029999 Japanese Patent Application Laid-Open No. 10-2015-0134687

The present invention monitors the state of a street lamp and the state of a street lamp in consideration of a problem of a street lamp management currently installed, particularly, a problem in management of a street lamp that is scattered in a wide area rather than a big city or a busy street, And to provide a device for transmission.

Particularly, the present invention can provide a low-cost, low-cost, and minimized expansion of communication infrastructure for communication equipment that transmits information monitored by a monitoring device of a streetlight, Device.

The inventors of the present invention have developed a low power wide area network (LPWAN) as a communication method for transmitting information monitored by a monitoring method of a streetlight, which is one of the measures to solve the problems of the present invention . In particular, 'LoRaWAN' was considered among LPWANs.

As shown in FIG. 1, conventional wireless communication systems support large capacity communication compared to low power wide area communication technologies such as LoRaWAN. However, in some wireless communication such as Wi-Fi (IEEE802.11ac), communication distance is about 50 m .

However, since the management system of the streetlight needs to receive monitoring information from a street lamp disposed at a remote place, and the monitoring information is not large in size, there is a need for a technology capable of communicating a small amount of data over a long distance Do. Accordingly, the inventors of the present invention have pointed out that a low power long distance wireless communication (LPWAN) such as LoRaWAN is suitable for application to the management system of a streetlight.

For this reason, the present invention applies a low power long distance wireless communication technology such as LoRaWAN to a streetlight management system. Specifically, a communication module required for low power long distance wireless communication is applied to a monitoring device attached to a streetlight.

LoRaWAN communication technology has high security using Advanced Encryption Standard base64 (AES base64) method unlike other wireless communication technologies such as Bluetooth or ZigBee.

Since the LoRaWAN communication is performed through the frequency band of the band (ISM Band) used for industrial, scientific, and medical purposes, the LoRaWAN communication module does not require the cost for the purchase of the frequency band, and the communication module such as ZigBee or LTE- The price is 1/5 of the price. Moreover, you can connect up to 20,000 clients at a time. This makes the initial installation cost and maintenance cost relatively inexpensive compared to other wireless communications.

In addition, LoRaWAN's communication distance is up to 16km, which makes it suitable for use in a wide area where communication infrastructure can not be installed close to each other. In particular, LoRaWAN communication automatically finds another channel that does not interfere even if there is interference on a specific channel, and uses it to automatically retransmit information even if transmission fails.

In the present invention, a low-power wide area communication technology including a LoRaWAN is applied to a monitoring apparatus for a streetlight that is disposed in each streetlight and monitors the state of the streetlight to transmit monitored information to a monitoring computer for monitoring the streetlight.

The monitoring device of the present invention includes at least one sensor for measuring information including position, current, voltage, illuminance, temperature, and humidity, a control module for receiving measurement data from the sensor and generating transmittable monitoring information, And the communication module of the monitoring device is composed of a low power wireless wide area communication module and transmits monitoring information to the monitoring computer through the low power communication network.

The monitoring apparatus of the present invention measures information about the operation of the streetlight, that is, the current and voltage supplied to the streetlight, measures illuminance, temperature and humidity as information about the streetlight, measures positioning information as the position information of the streetlight , And transmits the measured information to the monitoring computer through the low power wireless wide area communication module.

The low power wireless wide area communication module uses the frequency band which does not use the frequency use cost, so the use cost is not required, and the module cost is low and the initial investment cost is low, so the operation cost and the investment cost are low.

Particularly, the information monitored by the streetlight is small in data size of the information, but even if there is no communication infrastructure including a communication repeater at a short distance depending on the position of the streetlight, it is required to be transmitted to a repeater existing in a long distance. The communication through is suitable for this characteristic.

In addition, the monitored information must be transmitted to the surveillance computer in a stable manner. In low-power wireless communication technology, even if the information transmission fails, the information is automatically retransmitted, thereby enabling reliable monitoring of the stable streetlight.

1 is a graph showing a range of a communication speed and a communication distance in a commercialized wireless communication technology.
FIG. 2 is a conceptual diagram illustrating the overall configuration of a management system using a monitoring device of a streetlight according to the present invention.
FIG. 3 is a diagram illustrating a configuration of a monitoring apparatus according to an embodiment of the present invention.
FIG. 4 is a diagram showing a main interface of a graphical user interface for an administrator in a monitoring computer constructed using LabView.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of a streetlight monitoring apparatus according to the present invention will be described with reference to the accompanying drawings.

First, the overall configuration of a monitoring system of a streetlight using the monitoring apparatus of the streetlight according to the present invention will be described with reference to FIG.

The monitoring apparatuses of the streetlights are connected to the monitoring apparatus according to the present invention. The monitoring apparatus of the streetlights transmits monitored information including its serial number and positioning information to the repeater using LoRaWAN communication, Transmits the information to the surveillance computer via Ethernet, and the surveillance computer confirms which streetlight the information transmitted through the serial number and the positioning information is from, and also confirms the state of the streetlight .

FIG. 3 shows an example of a monitoring apparatus according to the present invention, which is arranged in each streetlight to perform monitoring.

Referring to FIG. 3, the monitoring apparatus according to the embodiment of the present invention includes a current and voltage sensor 11, a temperature and humidity sensor 12, an illuminance sensor 14, These sensors are connected to a Raspberry Pi control module, which functions as a control unit 20. The sensors are connected to a general purpose input / output (GPIO) module of the Raspberry Pi module by a PCB (PCB) ) Pin.

Table 1 below shows the communication method between each sensor and the Raspberry Pi control unit.

The ambient light sensor 14 and the current and voltage sensor 11 are using SPI communication, and the temperature and humidity sensor 12 communicates using the GPIO pin. Since the voltage and current sensor 11 used in the present embodiment uses a precise analog value, an analog-to-digital converter (ADC) converter is connected to the digital value so that the control unit can process the data. Also, Universal Asynchronous Receiver / Transmitter (UART) communication is used to connect the GPS module and LoRaWAN module to the controller.

Devices Temperature and humidity Current and voltage Illuminance GPS module Communication module Model DHT22 attopilot PCF8591 island-746 LoRaWAN Communication method GPIO SPI UART

The monitoring apparatus of the present embodiment measures a plurality of sensor values connected to the substrate using the pins of the Raspberry Pi module 20 and the USB port. Voltage and current values are required to understand the state of the streetlight in real time. If it is confirmed that the power supply of the street lamp is unstable or there is a problem from the information about the measured voltage and current, the administrator who confirms this information on the monitoring computer resolves the problem and reduces the time to be left untreated.

Also. For example, street lights should be blinking when fog occurs around a streetlight, causing the ambient humidity to rise or the night environment becomes dark or bright. Such information can be confirmed through the information measured by the temperature and humidity sensor 12 and the illuminance sensor 14, and an administrator can cope with it.

Thus, the status of the streetlight and the environment around the streetlight are monitored based on the information received from the monitoring device, so that the flicker and brightness can be adjusted according to the situation.

The monitoring system of the street lamp operating including the monitoring apparatus according to the present embodiment operates as follows.

When monitoring is started by the monitoring device attached to each streetlight, the Raspberry Pi module 20 measures data using various sensors and transmits data to the repeater (see FIG. 2) through the communication module 30 do.

If the first event identifies a change in the status of the streetlight, the surveillance computer informs the administrator and displays the identification number of the streetlight. The administrator resets the state of the streetlight through a separate streetlight control route, thereby attempting to restore the streetlight to its original state.

After resetting, if the streetlight monitoring device measures the status of the streetlight and sends related information, the administrator checks the status of the streetlight through the surveillance computer. If there is no problem, the manager continuously checks the state information of the streetlight. It is identified as a street light, registered in the management system list, and dispatched to the installation site of the street light to repair the street light.

The second event is to check the environment change around the streetlight and to control the LED of the streetlight according to the situation of the streetlight. These environmental changes are temperature and humidity information from temperature and humidity sensors and illuminance information from the illuminance sensor. The manager can determine based on the information transmitted by the monitoring device, and can take a corresponding action, based on the fogged situation and the darkness around the streetlight.

Next, a process of processing measured data and transmitting the measured data by the sensors of the monitoring apparatus of the present embodiment will be described.

Since the LoRaWAN communication module 30 for transmitting information measured by the sensors communicates using a low-power long-distance wireless communication method, the lifetime and the communication distance of the module are long, while the amount of data that can be transmitted in one packet is about 80 bytes And as the size of the data frame increases, the probability of data loss increases, and the transmission rate is significantly lowered.

To solve this problem, we can reduce the data size by using two methods.

First, the data measured using the sensors are sorted to have the same shape as the data frame of Table 2, and the data size is reduced by converting from decimal to hexadecimal, and then transmitted to the router.

Number Volt Current Intensity Humidity Temporary Time Latitude Longitude Data 1 byte 3byte 3byte 2byte 2byte 2byte 6byte 8byte 9byte 6byte

LoRaWAN communication transmits data after encrypting data using AES base64 method. The repeater decodes the transmitted data using a decoder and transmits the data to the monitoring computer by using TCP / IP communication. TCP / IP communication is more reliable than other communications and does not incur the separate data cost and installation cost.

FIG. 4 is a main interface of a graphical user interface for an administrator in a surveillance computer constructed using LabView, and is composed of data divided into an IP setting portion, an entire data, and an identification number so as to be able to efficiently monitor and control in real time.

First, the IP is set to bring data in the repeater, and data having the same form as the data frame of Table 2 is divided into respective data values and output to the entire data portion. In this part, all the data is output irrespective of the identification number assigned to each streetlight. If any of the connected streetlights has a problem, it becomes an emergency alarm.

Divides the data according to the identification number assigned to each Raspberry Pi control module, that is, the identification number of each streetlight, and periodically stores the data values divided by the total data value and the identification number. The data divided by the identification number constitutes a status notification window so that the voltage and current for visually confirming the status of each streetlight can be visually checked and can be adjusted to blink and brightness according to the situation of the streetlight and the environment around the streetlight. In addition, the illuminance and temperature and humidity can be configured in the form of a thermometer so that the display color of the thermometer changes when a specific environment such as fog or night occurs.

By using this, it is possible to monitor the street light in real time and solve it in a short time even if a problem occurs, and it is possible to manually operate the weather lamp or alarm by adjusting the flashing and brightness of the installed street lamps remotely.

In order to evaluate the performance of the monitoring system constructed by the monitoring apparatus according to the present invention, a total of two items were selected and evaluated.

We measured the communication distance of LoRaWAN in indoor Non-Line of Sight (NLOS) environment and measured the maximum distance for stable communication and measured it in indoor Line of Sight (LOS) environment. In addition, the error rate of the measured data using the sensors and the data measured by the voltage and current dedicated digital multimeter, illuminometer, and hygrometer were analyzed. This error rate is compared with the error rate based on the data sheet of each sensor.

In order to measure the wireless transmission distance of the LoRaWAN communication module, a computer, a repeater to be connected to the LoRaWAN, and a monitoring device of the present embodiment to be attached to the streetlight are provided with a test bed having a LoRaWAN communication module and a Raspberry Pi module and sensors, Respectively. In the indoor environment, the distance between the computer and the repeater is set to 2 m, and the distance between the repeater and the monitoring device is configured as shown in Table 3 below to measure the intensity of the signal depending on the distance. At this time, the strength of the signal was measured by the received signal strength indicator (RSSI) of the LoRaWAN output to the log window of the repeater.

Distance (m) Communication strength (dBm) 0 -30 10 -48 30 -59 50 -74 70 -98

In the outdoor environment, the distance between the surveillance computer and the repeater is set to 2 m, and the distance between the repeater and the monitoring device is configured as shown in Table 4 to measure the intensity of the signal depending on the distance.

Distance (m) Communication strength (dBm) 300 -52 600 -63 900 -77 1200 -89 1500 -101

The minimum communication strength for stable LoRaWAN communication is about -100dBm. Based on the above test, it is confirmed that the communication can be stably performed up to 70m in NLOS environment and 1.5km in outdoor LOS environment .

As shown in Table 5 below, Wisys Technologies' EZLuz system using ZigBee communication has a maximum communication distance of about 100 meters between the streetlight and the server, and about 210,000 won per communication module. You can also connect about 100 devices to one server. CITY SENSE system uses IEEE 802.15.4 communication, and the maximum communication distance between the street light and the server is about 1km, and the communication module is about 120,000 won per one. You can also connect about 250 devices to a server.

The streetlight management system using the LoRaWAN communication according to the present invention can communicate between the streetlight and the server by about 1.5 km in the outdoor environment and the communication module costs about 80,000 won per one. It also has about 20,000 devices connected to one server, which means it has higher efficiency at a lower cost than existing systems.

Monitoring device EZLuz CITY SENSE Invention Communication method ZigBee IEEE 802.15.4 LoRaWAN Communication distance (m) 100m 1km 1.5km Price (won) 210,000 120,000 8,000 Number of connectable devices 100 250 20,000

The indoor environment of a large number of buildings was used as a test environment, and sensor values were measured using one monitoring apparatus according to the present invention. For comparison, measurements were made at the same position using a digital multimeter, a hygrometer, and an illuminometer. Table 6 shows the measured values, and the measured error rates and the error rates from the data sheets can be compared and analyzed.

The sensor measurements of the present invention Measured values in separate measuring equipment Error rate Temperature 21 ℃ 20 ℃ 4.76% Humidity 29% 31% 6.45% electric current 0.271A 0.265A 2.21% Voltage 3.03V 3.11V 2.64% Illuminance 67LUX 60LUX 10.4%

The existing streetlight monitoring apparatus and management system has low penetration rate due to high initial cost and inefficiency in operation cost. However, when the monitoring apparatus using the LoRaWAN proposed in the present invention is used, Can be efficiently managed.

In the present invention, a low-power long distance communication using a LoRaWAN is performed using a monitoring device using a plurality of sensors. The data received through the repeater can be monitored through a computer via the LabView-based GUI, and automatic brightness control, flashing and manual LED control are possible. Furthermore, by adjusting the blinking and brightness to suit the environment around the streetlight, it is possible to prevent light pollution in residential areas and reduce unnecessary energy.

While the present invention has been described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the appended claims. Of course.

Claims (4)

A monitoring device for a streetlight, the monitoring device being disposed in each streetlight to monitor the state of the streetlight to transmit monitored information to a monitoring computer for monitoring the streetlight,
At least one sensor for measuring information including position, current, voltage, illuminance, temperature and humidity, a control module for receiving measurement data from the sensor and generating transmittable monitoring information, a communication module for transmitting information from the control module / RTI >
Wherein the communication module of the monitoring device is comprised of a low power wireless wide area communication module and transmits monitoring information to the monitoring computer through a low power communication network. The method according to claim 1,
Wherein the communication module is a LoRaWAN communication module. The method according to claim 1,
Wherein the communication module transmits information at a frequency of the ISM band. The monitoring device of claim 1, wherein the control module is configured to be able to simultaneously receive data from each sensor, the Raspberry Pi module.

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