KR102164717B1 - LoRa Based Multi-Hop Communication System - Google Patents

Abstract

A multi-hop communication system based on long range (LoRa) is disclosed. According to the present invention, the multi-hop communication system based on LoRa comprises: a user terminal for generating destination information and control information; a plurality of controllers; a plurality of control-hops which receives an information frame and analyzes a hop coefficient and control information, controls the operation of the controller according to the control information based on the hop coefficient, or retransmitting the information frame, and consists of a main control-hop and a sub control-hop; and a concentrator for generating the hop coefficient matching the destination information based on connection information including connection map information between the plurality of control-hops, and generating and transmitting the information frame including the hop coefficient and the control information. The concentrator and the plurality of control-hops communicate based on LoRa, the main control-hop communicates directly with the concentrator, and the sub control-hop communicates with the concentrator via the main control-hop or another sub control-hop.

Description

LoRa Based Multi-Hop Communication System

The present invention (Disclosure) relates to a LoRa-based multi-hop communication system, and specifically, it is possible to solve the inconvenience of installation and maintenance in a wired communication method, and to solve the problem of limiting physical distance in a wireless communication method. It relates to a LoRa-based multi-hop communication system.

Here, background technology related to the present invention is provided, and these do not necessarily mean known technology (This section provides background information related to the present disclosure which is not necessarily prior art).

The Modbus-based LoRa wireless communication system is a communication method that combines the classic wired communication-based Modbus protocol and the low-power long-distance wireless communication LoRa protocol.

While the frame itself is simple and easy to implement, it is possible to overcome the problems of installation and maintenance, which are disadvantages of wired communication, so that data exchange over a relatively long distance in the industrial field is easy. In addition, it is used for data collection and processing of controllers such as Digital Motor Protector (DMP) and Intelligence Motor Protection and Controller (IMPC).

LoRa wireless communication is a protocol that promotes a long distance communication distance as an advantage over conventional wireless communication, and its implementation method is not complicated and is a communication method using relatively low power. In addition, it is easy to form a star network by connecting several sensors to one node, including the multi-sensor function.

LoRa communication is a wireless communication method that emphasizes low power and long distance, and is characterized by low cost.

In particular, it is specialized in ways to use IoT devices and sensor measurement applications that exchange data of specific periods (minutes and hours), rather than data exchanged in real time. In addition, users who have used communication modules such as Bluetooth, WiFi, and ZigBee have the advantage of being very easy to adopt and use technology because they have accessibility that can be used without difficulty.

Using this advantage, by using LoRa wireless communication for current measurement monitoring in the past, data is remotely transmitted from controllers within a wireless communication radius centered on the concentrator (AP), and the desired setting value is transmitted remotely. Pursuing convenience.

1 is a diagram illustrating a conventional Star Network scheme.

The Star Network method is a generic term for a network network that puts all controllers within the range of one concentrator (AP, Access Point) and exchanges wireless communication with the controllers within the communication range.

In particular, in the conventional intelligent motor protection relay, only wired communication is used in accordance with the Modbus protocol protocol using RS485 communication, which is a wired communication, or parameters are exchanged or measurement data is transmitted using only the Star Network-based 1:1 communication described above. come.

As described above, the existing wireless communication techniques for electronic protection relays or various controllers are in the Star-Network method, and multiple lower nodes, that is, controllers, are connected to one Access Point to access a large amount of work in a 1:1 method. Only data exchange within the limited wireless communication distance of the point itself was possible.

In addition, since the LoRa protocol is a low-power-based wireless communication protocol, it is vulnerable to a large amount of shielding film in industrial sites and a large amount of noise in a communication environment, so that the theoretical original communication distance can be used only very limitedly.

For this reason, it is difficult to cover the entire practical wide industrial site, and there is a problem that it is easily affected by radio communication interference elements such as noise or shielding.

In order to solve this problem, it is possible to temporarily solve the problem by placing an Access Point device for each specific point, but the cost aspect and communication efficiency are very low.

To solve these problems, it is possible to solve the inconvenience of installation and maintenance in the existing wired communication method, and an electronic protection relay or controller that can solve the physical distance limitation problem that occurs in the LoRa-based wireless communication method. The development of a new communication system for controlling the controller in the industrial field is urgent.

1. Korean Patent Application Publication No. 10-2008-0042675

The present invention (Disclosure) provides a LoRa-based multi-hop communication system that is simple to install hardware, can communicate with multiple intelligent motor protection relays or controllers at the same time, and can be used in a wide range even with low power. It is for work purposes.

Here, a summary of the present invention is provided, and this section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features).

In order to solve the above problems, a LoRa-based multi-hop communication system according to one of the various aspects describing the present invention includes a user terminal for generating destination information and control information; A plurality of controllers; Receives the information frame, analyzes the hop coefficient and control information, controls the operation of the controller according to the control information based on the hop coefficient, or retransmits the information frame, and performs main control-hop and sub control- A plurality of control-hops consisting of hops; And generating a hop coefficient matching the destination information based on control-hop connection information including connection map information between the plurality of control-hops, and generating the information frame including the hop coefficient and the control information. A concentrator for generating and transmitting; wherein the concentrator and the plurality of control-hops communicate based on LoRa, and the main control-hop communicates directly with the concentrator, and the sub-control-hop is the main control- It communicates with the concentrator via a hop or another sub-control-hop.

In the LoRa-based multi-hop communication system according to an aspect of the present invention, the user terminal generates a search message, and the concentrator receives the search message, broadcasts it, and receives a confirmation message. A transmitter/receiver unit, a concentrator-MCU (Micro Control Unit) for generating the hop connection information based on the destination information and the confirmation message, and a concentrator-memory storing the hop connection information, and the plurality of The control-hop includes a LoRa communication unit, and the LoRa communication unit of the main control-hop receives the search message from the concentrator and generates confirmation information corresponding to the search message, and the sub-control- Broadcasting the search message to a hop, receiving confirmation information of the sub-control-hop, merging it with the confirmation information generated by itself to generate the confirmation message, transmitting the confirmation message, and The LoRa communication unit may receive the search message broadcasted by the main control-hop, generate the confirmation information, and transmit the confirmation information.

In the LoRa-based multi-hop communication system according to an aspect of the present invention, the LoRa communication unit includes: a LoRa MCU that analyzes the search message to generate the confirmation information and the confirmation message; A LoRa transceiver for transmitting and receiving LoRa information including the information frame, the search message, the confirmation information, and the confirmation message; And a LoRa receiving buffer temporarily storing the LoRa information received by the LoRa transmitting and receiving unit, and a LoRa transmitting buffer temporarily storing the LoRa information transmitted through the LoRa transmitting and receiving unit.

In the LoRa-based multi-hop communication system according to an aspect of the present invention, the search message includes a list of the plurality of controller MAC addresses, and the LoRa MCU includes any one of the MAC address lists. The confirmation information may be generated according to whether or not the MAC address matches its own MAC address.

In the LoRa-based multi-hop communication system according to an aspect of the present invention, the control-hop further includes a control unit, and the control unit includes a control MCU that controls the controller according to the control information, The control MCU may include a controller memory for storing information generated in the process of controlling the controller.

According to the present invention, by using a multi-hop radio scheme, it is possible to solve the problem of transmission/reception distance limitation occurring in a general Star Network-based single hop communication.

According to the present invention, by adding a hop coefficient to a frame, it is possible to selectively and simultaneously control at least one or more specific controllers.

1 is a diagram illustrating a conventional Star Network scheme.
2 is a diagram for explaining an embodiment of a multi-hop communication system based on LoRa according to the present invention.
3 is a diagram for describing control-hop connection information.
Fig. 4 is a diagram for explaining the structure of an information frame.
5 is a diagram for explaining the configuration of a control-hop in the LoRa-based multi-hop communication system according to the present embodiment.
6 is a diagram illustrating a process of generating control-hop connection information in another embodiment of the LoRa-based multi-hop communication system according to the present invention.
7 is a view for explaining another form of control-hop connection information.

Hereinafter, an embodiment of implementing the LoRa-based multi-hop communication system according to the present invention will be described in detail with reference to the drawings.

However, the intrinsic technical idea of the present invention cannot be said to be limited by the embodiments to be described below, and the intrinsic technical idea of the present invention is given below by a person skilled in the art. It turns out to cover the range that can be easily proposed by a method of substitution or change of the embodiment described in FIG.

In addition, since the terms used below are selected for convenience of description, in grasping the intrinsic technical idea of the present invention, it is not limited to the dictionary meaning and is appropriately interpreted as a meaning consistent with the technical idea of the present invention. Should be.

2 is a diagram illustrating an embodiment of a multi-hop communication system based on LoRa according to the present invention.

3 is a diagram illustrating control-hop connection information, and FIG. 4 is a diagram illustrating a structure of an information frame.

5 is a diagram for explaining the configuration of a control-hop in the LoRa-based multi-hop communication system according to the present embodiment.

Referring to FIG. 2, the LoRa-based multi-hop communication system according to the present embodiment includes a user terminal 100, a controller 200, a control-hop 300, and a concentrator 400.

The user terminal 100 generates destination information and control information.

The controller 200 controls operation remotely by a user, and a plurality of controllers 200 may be disposed in a specific space, and may be operated independently of each other.

The control-hop 300 receives the information frame, analyzes the hop coefficient and control information, and controls the operation of the controller 200 according to the control information based on the hop coefficient, or retransmits the information frame.

In addition, the control-hop 300 is composed of a main control-hop 300 and a sub-control-hop 300.

The main control-hop (control-hop 10, 30) communicates directly with the concentrator 400, and the sub-control-hop (control-hop 11, 31, 32) communicates with the main control-hop or another sub-control-hop. It communicates with the concentrator 400 through the medium.

The concentrator (AP, Access Point, 400) generates a hop coefficient matching destination information based on the control-hop connection information, and generates and transmits an information frame including the hop coefficient and control information.

The control-hop connection information includes connection map information between the concentrator 400 and the plurality of control-hops 300.

In the LoRa-based multi-hop communication system according to the present embodiment, the concentrator 400 and the plurality of control-hops 300 communicate based on LoRa.

Referring to FIG. 2, in the LoRa-based multi-hop communication system according to the present invention, a control-hop 11 in which wireless communication is impossible because it is located at a distance from the concentrator 400 directly communicates with the concentrator 400. Communicate with

Here, the control-hop 10 is the main control-hop, and the control-hop 11 is the sub-control-hop.

The destination information is information on whether the controller 200 connected to either the main control-hop or the sub-control-hop is the destination, or the controller 200 connected to the main control-hop and the sub-control-hop is the destination. Includes.

The hop coefficient is obtained by converting such destination information into predetermined numerical information.

Assuming that the number of main control-hop and sub-control-hop is one, the hop coefficient and destination information will be described as follows.

If the destination included in the destination information is a single destination as the main control-hop, the hop coefficient may be 1. If the destination included in the destination information is a single destination as a sub-control-hop, the hop coefficient may be 2.

On the other hand, if the destination included in the destination information is a plurality of destinations including both the main control-hop and the sub-control-hop, the hop coefficient may be 3.

When two or more sub-control-hops are formed in one main control-hop, the value of the hop coefficient may increase according to the number of sub-control-hops.

The main control-hop, sub-control-hop, and control-hop connection information will be described with reference to FIG. 3.

As can be seen in FIG. 3, a control-hop disposed outside the radio communication radius of each concentrator AP may communicate with the concentrator via another control-hop.

Control-hops 10, 20, 30 and 40 each communicate directly with the concentrator (AP).

Control-hops 11, 21, 31, and 41 that are located at a distance from the concentrator (AP) and out of the radio communication radius are difficult to communicate with each concentrator (AP).

However, the control-hops 11, 21, 31, and 41 are located relatively close to the control-hops 10, 20, 30, and 40 in which wireless communication is possible.

Accordingly, control-hops 11, 21, 31, and 41 are relay-connected to control-hops 10, 20, 30, and 40, respectively, to communicate. Control-hops 10, 20, 30, and 40 serve as repeaters between control-hops 11, 21, 31, and 41 and the concentrator (AP).

Control-hops 10, 20, 30, 40 are the main control-hops, and control-hops 11, 21, 31, and 41 are sub-control-hops.

As shown in FIG. 3, the control-hop connection information includes the connection status of the concentrator (AP), the control-hop 300, and the main control-hop and the sub-control-hop in the form of a map.

Accordingly, referring to FIGS. 2 to 3, the LoRa-based multi-hop communication system according to the present invention can solve the limitation of the physical distance at which the concentrator (AP) 400 can communicate.

Further, referring to FIG. 4, the information frame includes a hop coefficient in its front end.

By using the hop coefficient, the main control-hop and the sub-control-hop can be controlled for each connection step.

In addition, if the hop count further includes the address of a control-hop or controller, for example, a Mac address, a controller connected to a single or multiple sub-control-hops connected to one main control-hop is specified. Can be controlled.

That is, the hop coefficient and the MAC address of the controller or control-hop are used as two-dimensional coordinates, so that a specific controller can be controlled.

5 is a diagram illustrating a configuration of a control-hop in a multi-hop communication system based on LoRa according to the present invention.

Referring to FIG. 5, the control-hop 300 may include a LoRa communication unit 310 and a control unit 320, respectively.

The LoRa communication unit 310 communicates with the concentrator 400 to receive an information frame or retransmit it to another control-hop 300.

The control unit 320 controls the operation of the controller 200.

The configurations of the above-described main control-hop and sub-control-hop are the same as shown in FIG. 5.

The control-hop 300 according to the present invention has a structure in which a conventional control unit 320 for controlling the controller 200 is combined with a LoRa communication unit 310 for wireless communication with a concentrator in a LoRa method.

Meanwhile, in another embodiment of the LoRa-based multi-hop communication system according to the present invention, the controller 200 may be an intelligent motor protection relay.

In addition, the control unit may include a control MCU that controls the controller according to the control information, and a control memory that stores information generated in the process of the control MCU controlling the controller.

6 is a diagram illustrating a process of generating control-hop connection information in another embodiment of the LoRa-based multi-hop communication system according to the present invention.

Referring to FIG. 6, in the LoRa-based multi-hop communication system according to the present embodiment, the user terminal 100 generates a search message and transmits it to the concentrator 400.

The concentrator 400 includes a concentrator-transmitting/receiving unit, a concentrator-MCU, and a concentrator-memory.

The concentrator-transmitting/receiving unit receives and broadcasts a search message and receives a confirmation message. The concentrator-MCU (Micro Control Unit) generates control-hop connection information based on the destination information and the confirmation message. The concentrator-memory stores control-hop connection information.

According to the present embodiment, the LoRa communication unit 310 of the main control-hop-in control-hop 10 directly receives a search message from the concentrator 400 and generates confirmation information corresponding to the search message. In addition, the control-hop 10 broadcasts a search message to the sub-control-hop 300 again and receives confirmation information of the sub-control-hop 300.

In addition, the LoRa communication unit of the main control-hop and control-hop 10 generates a confirmation message by merging the confirmation information generated by itself and another confirmation information received from the sub-control-hop 300, and concentrates this. It transmits to the machine 400.

The LoRa communication unit of the sub-control-hop 300 receives the search message broadcasted by the main control-hop-in control-hop 10, generates confirmation information, and transmits it to the main control-hop.

The LoRa-based multi-hop communication system according to the present embodiment collects information on the connection type of the concentrator 400, the main control-hop (control-hop 10), and the sub-control-hop (control-hop 11). Create control-hop connection information.

In an actual field in which a control-hop and a controller connected thereto are arranged, it is difficult for an operator or an administrator to directly define the connection between the main control-hop and the sub-control-hop. This is because the number of controllers may be large, and wireless communication obstacles in the field, that is, EMI and various devices for shielding them, may be scattered.

The LoRa-based multi-hop communication system according to the present embodiment receives confirmation information received from all control-hops by broadcasting a search message, and automatically generates control-hop connection information at the time point.

The control-hop connection information formed in this way may use a control-hop or a unique number of each controller.

The unique number may preferably be a Mac address.

Accordingly, a user using a user terminal can freely control a desired controller by generating destination information only with the controller's unique number.

In addition, in the LoRa-based multi-hop communication system according to the present embodiment, the LoRa communication unit includes a LoRa MCU, a LoRA transmitting and receiving unit, a LoRa receiving buffer, and a LoRa transmitting buffer.

Lora MCU analyzes the search message and generates confirmation information and confirmation message.

The LoRa transceiver unit transmits and receives LoRa information including an information frame, a search message, confirmation information, and confirmation message.

The LoRa receiving buffer temporarily stores LoRa information received by the LoRa transceiver, and the LoRa transmitting buffer temporarily stores LoRa information transmitted through the LoRa transceiver.

When the control-hop connection information is generated as described above, the LoRa communication unit of each control-hop may set itself as a main control-hop or a sub-control-hop.

In addition, after the device address of the LoRa communication unit is included in each of the confirmation information, and confirmation information for a search message generated once is generated once, the confirmation information may not be generated again.

Accordingly, when a search message from a plurality of main control-hops is repeatedly received in one sub-control-hop, the effective distance in wireless communication can be connected to the main control-hop arranged at the shortest distance.

The search message includes a list of a plurality of controller MAC addresses, and the LoRa MCU may generate confirmation information according to whether any one of the MAC address lists matches its own MAC address.

Also, referring to FIG. 6, the control-hop 300 may have a timer therein.

The timer measures the transmission/reception time of all information transmitted/received through the LoRa transceiver, and the LoRa MCU determines whether or not to determine a communication error based on this.

For example, after a certain transmission information is transmitted, if the corresponding reception information is not received, the transmission information is retransmitted after a certain period of time. If the number of retransmissions exceeds the specified number, the communication line is determined as a communication error.

If it is determined as a communication error, the reception information from the corresponding communication line is no longer waiting.

In the LoRa-based multi-hop communication system according to the present invention, communication error determination using a timer mainly functions in two ways.

First, it is the transmission and reception quality evaluation.

All communications between the concentrator and the control-hop, and the control-hop and the control-hop are determined for communication errors in the manner described above.

If the communication error determination is not made, incomplete communication may be repeated infinitely, or a problem may arise that waits for receiving information to be received for an infinite amount of time even though communication is impossible and the received information is not received.

Second, when a communication error determination occurs, the above-described search message is retransmitted to reset the control-hop connection information.

If a communication error is determined in a specific communication line from the already completed control-hop connection information, it means that the corresponding communication line among the control-hop connection information cannot be used.

As described above, in a field in which a controller is used, various elements that impede the quality of wireless communication may change in real time.

When the initial control-hop connection information is generated, even if normal communication is possible, it is necessary to reset the control-hop connection information as the strength and range of the radio communication quality impairing factor changes over time.

However, the control-hop connection information update, which updates the control-hop connection information, is a factor that hinders workability in the field if it is repeated at a specific time period.

Accordingly, in the LoRa-based multi-hop communication system according to the present invention, communication error determination using a timer is used as one of the necessary elements for updating the control-hop connection information.

That is, when a communication error determination occurs in the process of performing work in the field using the set control-hop connection information, the control-hop connection information is updated.

This is because a communication line capable of replacing the communication line for which the communication error has been determined can be newly searched.

7 is a diagram illustrating another form of control-hop connection information.

According to FIG. 7, a control-hop outside the wireless communication radius of the concentrator communicates with the concentrator indirectly through the main control-hop as a sub-control-hop.

In this case, some of the sub-control-hops may be connected to a concentrator AP located at a distance, not a concentrator AP having a physical distance disposed at the shortest distance.

Control hop 41, for example, is a concentrator with concentrator 4 arranged in the nearest vicinity.

However, it can be connected to concentrator 3 through an external relay connection path through control-hop 32 connected to concentrator 3.

Control-hop 41 can be connected to concentrator 4 through control-hop 40, but the communication distance with control-hop 32 is short. Accordingly, the control-hop 41 is physically adjacent to the concentrator 4, but may be configured as a sub-control-hop belonging to the concentrator 3 in consideration of a wireless communication path.

This same phenomenon applies equally to control-hop 31 and control-hop 20.

As described above, in the LoRa-based multi-hop communication system according to the present invention, control-hop connection information is generated.

The control-hop connection information is generated based on a search message broadcast through a user terminal and a concentrator, and response information generated in each control-hop corresponding thereto.

As the control-hop acts as another control-hop repeater, each concentrator and all control-hops are linked to each other in the shortest distance, and the map information in which all concentrators and control-hops are connected is control-hop connection information.

The state of wireless communication between the concentrator and the control-hop and the control-hop and the control-hop is not always constant.

Depending on not only the physical structure of the site where the controller is installed, but also the operating conditions and movement conditions of various facilities that consume high power, the elements of radio interference in the site change from moment to moment.

The control-hop connection information according to the present invention forms map information in which the effective communication distance between each concentrator and each control-hop is the shortest distance.

Accordingly, the LoRa-based multi-hop communication system according to the present invention can always form an optimal communication network in a field situation.

Claims (5)

A user terminal for generating destination information and control information;
A plurality of controllers;
Receive an information frame to analyze hop coefficient and control information, control the operation of the controller according to the control information based on the hop coefficient, or retransmit the information frame, and main control-hop and sub-control-hop A plurality of control-hops consisting of; And
Generates a hop coefficient matching the destination information based on control-hop connection information including connection map information between the plurality of control-hops, and generates the information frame including the hop coefficient and the control information Including; concentrator to transmit by,
The concentrator and the plurality of control-hops communicate based on LoRa,
The main control-hop communicates directly with the concentrator,
The sub control-hop communicates with the concentrator via the main control-hop or another sub control-hop, and
The user terminal generates a search message,
The concentrator,
A concentrator-transmitting and receiving unit receiving and broadcasting the search message and receiving a confirmation message, and a concentrator-MCU (Micro Control Unit) and the hop generating hop connection information based on the destination information and the confirmation message. Concentrator-memory in which connection information is stored, and
The plurality of control-hops,
Including a LoRa communication unit,
The LoRa communication unit of the main control-hop,
It receives the search message from the concentrator and generates confirmation information corresponding to the search message, broadcasts the search message to the sub-control-hop, and receives confirmation information of the sub-control-hop, which is generated by itself. Merges with the confirmation information to generate the confirmation message, and sends the confirmation message,
The LoRa communication unit of the sub-control-hop,
LoRa-based multi-hop communication system for generating the confirmation information by receiving the search message broadcasted by the main control-hop, and transmitting the confirmation information delete The method according to claim 1,
The LoRa communication unit,
A LoRa MCU that analyzes the search message to generate the confirmation information and the confirmation message;
A LoRa transceiver for transmitting and receiving LoRa information including the information frame, the search message, the confirmation information, and the confirmation message; And
LoRa-based multi-hop communication system comprising; a LoRa receiving buffer temporarily storing the LoRa information received by the LoRa transmitting and receiving unit, and a LoRa transmitting buffer temporarily storing the LoRa information transmitted through the LoRa transmitting and receiving unit. The method of claim 3,
The above search message is:
Includes a list of the plurality of controller MAC address (MAC Address),
The LoRa MCU,
A LoRa-based multi-hop communication system that generates the identification information according to whether any one of the MAC address list matches its own MAC address. The method according to claim 1,
The control-hop is,
Further comprising a control unit,
The control unit,
A LoRa-based multi-hop communication system comprising a control MCU that controls the controller according to the control information, and a controller memory that stores information generated in a process of the control MCU controlling the controller.

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