KR101213534B1 - Remote control system and method for underwater robot - Google Patents

Abstract

The present invention relates to an underwater robot remote control system and method capable of remotely controlling a plurality of underwater robots.
The remote control method of the present invention includes the steps of: broadcasting a preamble message to a plurality of underwater robots in a cluster to which the gateway belongs in the advertisement section of the underwater communication protocol; Selecting a cluster to join each of the plurality of underwater robots in a join section of the underwater communication protocol, and transmitting a join message including request information for joining the selected cluster and location information thereof to the gateway; Allocating a beacon frame to the plurality of underwater robots in the beacon section of the underwater communication protocol in the gateway and allocating a time slot for data transmission according to the location information of the underwater robot; Transmitting, by the underwater robot, the underwater information collection data to the gateway through time slots respectively allocated in the control section of the underwater communication protocol; And broadcasting, at the gateway, a control message for the underwater robot received from an upper node in the data transmission section of the underwater communication protocol to the plurality of underwater robots.

Description

Underwater robot remote control system and method {REMOTE CONTROL SYSTEM AND METHOD FOR UNDERWATER ROBOT}

The present invention relates to an underwater robot remote control system and method, and more particularly, to a remote underwater robot remote control system that can remotely control a plurality of underwater robots by transmitting a control message to the underwater robot using a sonar signal and It is about a method.

Communication in the aquatic environment can be used in a variety of areas, including marine data collection, seabed exploration and development, disaster prevention, marine environmental monitoring, military tactical monitoring, and route discovery. Such underwater communication is further activated by underwater robots such as AUV (Autonomous Underwater Vehicle) and ROV (Remotely Operated Vehicle). For efficient operation of the seabed exploration and development system, it is essential to build a control system for underwater robots using underwater wireless communication.

However, underwater communication, unlike radio (RF) communication used on the ground, because electromagnetic waves and light waves rapidly attenuate only limited communication by underwater sound waves. Acoustic wave communication used underwater has a very limited bandwidth, so there is a small amount of data that can be transmitted at one time and damage the underwater channel due to multipath and fading. In addition, sonar communication has a problem of battery consumption due to long transmission delay and packet collision.

In the past, nodes have secured channels in advance and transmit data through a given channel, which is suitable for underwater environments, and has been studied for energy efficiency. This sets the transmission channel of each node by transmitting a control message to secure the channel in the initialization section and notifying adjacent nodes of their channel usage time. However, since the channel is set in advance, when there is no data to be transmitted, unnecessary waste of the channel is generated, and when the number of nodes increases due to the number of nodes, energy consumption and transmission delay due to channel collision occur.

In addition, as a method of minimizing collisions during data transmission to overcome this problem, a technique for minimizing energy consumption and maximizing throughput is proposed in consideration of high transmission delay and low bandwidth in an underwater environment. In this technology, the transmission cycle section is divided into a slot reservation section and a data transmission section. The slot reservation section is a section for reserving slots necessary for contention on the basis of contention, and data transmission section is excluded when data transmission is performed. And inactive, minimizing energy consumption. However, since all nodes must remain active in the slot reservation interval, unnecessary energy loss may occur, and if nodes within the same transmission range transmit reservation messages using the same reservation slot at the same time, a collision occurs.

The present invention has been proposed to solve the above problems of the prior art, a remote underwater robot remote control system for preventing collisions by transmitting data from a plurality of underwater robots according to a pre-allocated time slot in the underwater environment and The purpose is to provide a method.

Another object of the present invention is to provide an underwater robot remote control system and method capable of guaranteeing real-time control of the underwater robot control by asynchronously controlling the underwater robot by transmitting an aperiodic control message to a plurality of underwater robots. have.

In addition, the present invention is a remote underwater robot that can increase the energy efficiency by broadcasting the control messages for each underwater robot received from the upper node into a single message through the buffering process (merging) to a single message It is an additional object to provide a control system and method.

Furthermore, another object of the present invention is to provide an underwater robot remote control system and method for preventing unnecessary energy consumption of other underwater robots when the robot enters and leaves the cluster.

According to an aspect of the present invention,

Broadcasting a preamble message to a plurality of underwater robots in a cluster to which the gateway belongs in the advertisement section of the underwater communication protocol; Selecting a cluster to join each of the plurality of underwater robots in a join section of the underwater communication protocol, and transmitting a join message including request information for joining the selected cluster and location information thereof to the gateway; Allocating a beacon frame to the plurality of underwater robots in the beacon section of the underwater communication protocol in the gateway and allocating a time slot for data transmission according to the location information of the underwater robot; Transmitting, by the underwater robot, the underwater information collection data to the gateway through time slots respectively allocated in the control section of the underwater communication protocol; And broadcasting, at the gateway, a control message for the underwater robot received from an upper node in the data transmission section of the underwater communication protocol to the plurality of underwater robots. It provides a remote control method of the underwater robot comprising a.

In an embodiment of the present disclosure, the allocating the timeslots may include allocating the timeslots in the order in which the distances from the gateway to the underwater robots are close using the position information of the underwater robots included in the join message.

In an embodiment of the present invention, the gateway receives aperiodic control message for the underwater robot from the upper node.

In an embodiment of the present disclosure, the broadcasting of the control message for the underwater robot may include: buffering each of the underwater robot control messages received aperiodically from the upper node at the gateway for a preset time; Merging the buffered control message to produce one unified control message; Encrypting the integration control message; And broadcasting the encrypted integrated control message to the plurality of underwater robots.

In an embodiment of the present invention, the underwater robot remote control method, when the new underwater robot enters into the cluster and receives the beacon frame broadcast from the gateway, the new underwater robot maintenance / sleep interval of the underwater communication protocol The method may further include transmitting a join message including the subscription request information for joining the cluster and its location information to the gateway.

In an embodiment of the present invention, the underwater robot remote control method, the beacon frame in the beacon interval of the next period of the underwater communication protocol in the gateway broadcasts each of the underwater robot by broadcasting a plurality of underwater robot including the new underwater robot Allocating a timeslot according to the position information; And transmitting the underwater information collection data to the gateway through the allocated timeslot in a control section of a next period of the underwater communication protocol in a plurality of underwater robots including the new underwater robot. As shown in FIG.

In an embodiment of the present invention, the underwater robot remote control method, the new underwater robot to the control message for each underwater robot received aperiodically from the upper node in the data transmission section of the next period of the underwater communication protocol in the gateway The method may further include broadcasting to a plurality of underwater robots, including.

In an embodiment of the present disclosure, broadcasting to the underwater robot may include: buffering each of the underwater robot control messages at the gateway; Merging the buffered control message to produce one unified control message; Encrypting the integration control message; And broadcasting the encrypted integrated control message to a plurality of underwater robots, including the new underwater robot.

In an embodiment of the present invention, the underwater robot remote control method, when the plurality of underwater robot moves the position and the distance to the gateway is changed in the joining section of the underwater communication protocol in the plurality of underwater robot Transmitting a join message including location information to the gateway; And at the gateway, broadcasting a beacon frame to the plurality of underwater robots in a beacon section of the underwater communication protocol, and allocating a time slot according to the changed position information of the underwater robot; And transmitting the underwater information collection data to the gateway through the allocated timeslot in a control section of the underwater communication protocol in the plurality of underwater robots. .

In an embodiment of the present disclosure, the allocating the timeslots may include allocating the timeslots in the order in which the distances from the gateway to the underwater robots are close using the changed position information of the underwater robots included in the join message. Do.

In an embodiment of the present invention, the underwater robot, which does not need to be allocated the timeslot, operates in a sleep mode in the maintenance / sleep period of the underwater communication protocol and maintains the inactive state.

In addition, the present invention for achieving the above object,

In the advertisement section of the underwater communication protocol, broadcast a preamble message into the cluster to which it belongs, and broadcast the beacon frame into the cluster in the beacon section of the underwater communication protocol to allocate a time slot for data transmission. A gateway for broadcasting a plurality of control messages received in a data transmission section into the cluster; In the join section of the underwater communication protocol, each of the clusters to which it joins is selected, and a join message including request information and its location information for joining the selected cluster is transmitted to the gateway, and the control section of the underwater communication protocol A plurality of underwater robots for transmitting the underwater information collection data to the gateway through the assigned timeslot; And an upper node that transmits the plurality of underwater robot-specific control messages aperiodically to the gateway through a wireless network.

In an embodiment of the present invention, the gateway allocates timeslots in the order of distance from the gateway to each of the underwater robots using location information of the underwater robots included in the join messages received from the plurality of underwater robots. .

In an embodiment of the present invention, the gateway buffers the plurality of underwater robot-specific control messages received aperiodically from the upper node for a predetermined time and merges the buffered plurality of control messages into one to integrate one. A control message is generated, and the integrated control message is encrypted and broadcasted to the plurality of underwater robots.

In an embodiment of the present invention, the underwater robot remote control system is a new underwater robot enters into the cluster and receives a beacon frame broadcast from the gateway in the new underwater robot in the maintenance / sleep interval of the underwater communication protocol The join message including the subscription request information and its location information for joining the cluster is transmitted to the gateway.

In an embodiment of the present invention, the underwater communication protocol includes a frame including an initialization section consisting of the advertisement section and the join section, and a superframe section consisting of the control section, the data transmission section, and the maintenance / sleep section.

In an embodiment of the present invention, the underwater robot remote control system has its own position in the join section of the underwater communication protocol in the plurality of underwater robots when the distance from the gateway is changed by moving the plurality of underwater robots position A join message including information is transmitted to the gateway, and the beacon frame is broadcast to the plurality of underwater robots in the beacon section of the underwater communication protocol, and the timeslot is allocated according to the changed position information of the underwater robot.

In addition,

An advertisement section in which the gateway broadcasts the preamble message to a plurality of underwater robots in its cluster; A join section for selecting a cluster to be joined by the plurality of underwater robots and transmitting a join message including request information for joining the selected cluster and location information thereof to the gateway; A beacon section for generating a beacon frame including the plurality of underwater robot information and time slot assignment information at the gateway and broadcasting to the plurality of underwater robots to allocate time slots for data transmission according to the position information of the underwater robot; A control section for transmitting the underwater information collection data to the gateway through timeslots assigned by the plurality of underwater robots; A data transmission section for broadcasting the underwater robot control message received aperiodically from the upper node in the gateway to the underwater robot; And a maintenance / sleep section that transmits a join message including subscription request information and location information for joining the cluster from the new underwater robot to the gateway when a new underwater robot enters the cluster. It provides an underwater communication protocol.

In an embodiment of the present invention, in the data transmission section, the gateway buffers the plurality of underwater robot-specific control messages transmitted aperiodically from the upper node for a predetermined time and merges the buffered plurality of control messages. It generates a single integrated control message to encrypt the integrated control message and broadcast it to the plurality of underwater robots.

Underwater robot remote control system and method according to the present invention has the following effects.

First, the present invention can prevent collisions between data periodically transmitted from a plurality of underwater robots in an underwater environment.

In addition, the present invention can control a plurality of underwater robots in the aquatic environment aperiodically at a desired time at a remote location.

In addition, the present invention can improve energy efficiency by merging and broadcasting a plurality of control messages to be transmitted to a plurality of underwater robots in an underwater environment.

Furthermore, the present invention can prevent unnecessary energy consumption of existing underwater robots even when a plurality of underwater robots enter and leave their clusters.

1 is a schematic configuration diagram of an underwater robot remote control system according to an embodiment of the present invention.
2 is a structural diagram of an underwater communication protocol according to an embodiment of the present invention.
3 is a view illustrating a process of generating an integrated control message by integrating a control message in a gateway according to an embodiment of the present invention.
4 is a flowchart illustrating a remote control method of a plurality of underwater robots according to an embodiment of the present invention.
5 is an exemplary diagram of a network topology for a case where a new underwater robot enters into a cluster according to another embodiment of the present invention.
6 is a flow chart for explaining a remote control method of the underwater robot according to another embodiment of the present invention in FIG.
7 is an exemplary diagram of a network topology for a case where an underwater robot moves in a cluster according to another embodiment of the present invention.
8 is a flow chart for explaining a remote control method of the underwater robot according to another embodiment of the present invention in FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The present invention transmits a control message aperiodically to a plurality of underwater robots based on sonar communication, and periodically transmits underwater information collection data by using a time slot assigned to each underwater robot. To this end, the present invention provides a MAC (MAC) protocol that is adaptive to changes in the state of a communication channel and flexible to changes in topology according to the mobility of underwater robots. In addition, the present invention provides an optimal communication method for remotely controlling the underwater robot using a Time Division Multiple Access (TDMA) based MAC protocol suitable for aquatic environments.

1 is a schematic diagram of an underwater robot remote control system according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the underwater robot remote control system of the present invention includes a ground node 110, a plurality of gateways 120, and a plurality of underwater robots 130. In the present invention, it can be seen that a clustering-based structured underwater network topology is formed. In the present embodiment, the network topology includes two clusters 140 and 141, and each cluster 140 and 141 includes a gateway 120 and a plurality of underwater robots 130.

The underwater robot 130 periodically collects a variety of underwater information in the underwater environment and transmits it to the gateway 120 located in the cluster to which it belongs using a radio wave signal. The gateway 120 serves as a head of the cluster to which it belongs, receives underwater information collection data periodically transmitted as a radio wave signal from a plurality of underwater robots 130 and transmits it to the ground node 110 through a wireless network. do. In an embodiment of the present invention, such a wireless network may use a code division multiple access (CDMA) network. To this end, by providing a device such as a base station, a base station controller, it is possible to transmit data to a wide range.

In addition, the gateway 120 generates a MAC layer based on the underwater information using the underwater information collection data periodically transmitted from the plurality of underwater robots 130 and continuously updates it. The gateway 120 estimates a change in the underwater communication channel of each underwater robot 130 based on the underwater information accumulated in the MAC layer, thereby causing a collision when each underwater robot 130 in the cluster to which it belongs transmits and receives data. Do time synchronization and time slot assignments.

In the present invention, an underwater communication protocol suitable for an underwater environment is provided in the network topology structure as described above, thereby performing data communication between the gateway 120 and the underwater robot 130. This underwater communication protocol is suitable for the underwater environment and is called P-MAC (Preamble-MAC) protocol as an adaptive and dynamic MAC (MAC) protocol. The present invention provides a system and method for performing a sonic communication using the P-MAC protocol to remotely control a plurality of underwater robots 130 through this.

2 is a structural diagram of an underwater communication protocol according to an embodiment of the present invention.

As shown in FIG. 2, the underwater communication protocol according to the present invention is an interval for initial topology formation and time synchronization, and the gateway 120 creates and updates an internal database, and performs time synchronization based on this. ) Is an initialization period 200 that joins the appropriate cluster, and a superframe period 270 for performing data transmission and for maintaining the network topology formed by the initialization period 200. Is done.

The initialization period 200 is divided into an advertisement period 210 and a join period 270.

The advertisement section 210 generates a preamble message based on the adaptive MAC protocol and is a section in which the gateway 120 broadcasts it to the plurality of underwater robots 130 at predetermined time intervals. The preamble message includes information such as sequence number, time interval, repetition count, and transmission history. According to the broadcasting of the preamble message, the plurality of underwater robots 130 may measure information such as channel status and channel variation, and through this, the gateway 120 may provide information necessary for dynamically configuring a cluster to which the gateway 120 belongs. Are utilized.

The join section 220 is a section for forming a network topology based on the information collected by the advertisement section 210. In this section 220, the plurality of underwater robots 130 selects a cluster to join, and transmits a join message to the gateway 120 to be joined to the cluster. The join message includes cluster subscription request information, location information of each underwater robot 130, channel status, channel variation, reception history, and the like. As a result, the gateway 120 may predict the propagation delay time of the underwater robot 130 through the contents of the join message. In addition, the gateway 120 generates a beacon frame, which will be described later, through join messages received from the plurality of underwater robots 130. The beacon frame 130 includes information of the underwater robot 130 participating in the cluster, allocation information of a time slot, interval and repetition period of the superframe, activation and deactivation information, and the like. Accordingly, the gateway 120 allocates an appropriate time slot for each underwater robot 130 in the control section of the next superframe section using the location information of the underwater robot 130.

Next, the superframe period 270 is largely beacon period (230), control period (240), data transmission period (data transmission period) 250 and maintenance / sleep period (maintenance & sleep period) 260.

The beacon section 230 is a section for sending the beacon frame generated as described above.

The control section 240 is a section for allocating an appropriate timeslot 241 through the location information of the plurality of underwater robots 130 obtained in the initialization section 210. At this time, the number of assignable timeslots 241 is variable and it is desirable to set the maximum number of nodes in a policy. The reason is that if a large number of timeslots are allocated without restriction, a large amount of time is allocated to data reception, which makes it difficult to guarantee real time. In addition, the control section 240 to the gateway 120, the data including the location information, underwater information collection data, etc. of each of the underwater robot 130 through the time slot 241 each of which is assigned a plurality of underwater robot (130) It is a section to transmit. Here, the position information of each underwater robot 130 is for periodically notifying the change in position according to the movement of the underwater robot (130).

The data transmission section 250 broadcasts the control message for each underwater robot 130 received aperiodically from the ground node 110 to the plurality of underwater robots 130 through an encapsulation process. It is a section. At this time, the gateway 120 receives a control message for each underwater robot 130 aperiodically from the ground node 110. The gateway 120 performs a process of merging into a single control message after buffering in an internal buffer device. After generating the integrated control message and broadcasts the integrated control message to a number of underwater robot (130). Therefore, in the above encryption process, the encryption process may be performed on one integrated control message instead of performing the encryption process for each control message for each underwater robot 130. As a result, each underwater robot 130 processes encryption and broadcasting of the integrated control message, thereby generating relatively low energy consumption and improving efficiency in terms of data processing.

When the new underwater robot 130 enters into the cluster, the maintenance / sleep section 260 generates a subscription message for joining the cluster in the activated state by operating the underwater robot 130 in the maintenance mode. It is a section to transmit to. As a result, the gateway 120 allocates a new timeslot 241 for the newly joined underwater robot 130 in the next control section 240. At this time, the existing underwater robot 130 that does not need to be assigned a new timeslot operates in the sleep mode to maintain an inactive state to prevent unnecessary energy consumption.

3 is a view illustrating a process of generating an integrated control message by integrating a control message in a gateway according to an embodiment of the present invention.

Referring to FIG. 3, the gateway 120 according to the present invention aperiodically receives a control message for each underwater robot 130 from the ground node 110 through a wireless network. Through this, the ground node 110 may perform remote control for each underwater robot 130. In this case, when the gateway 120 receives the control message for each underwater robot 130 aperiodically, the integrated control device buffers the control message for a predetermined time t using an internal buffer device (not shown). Create as a message. Such an integrated control message may preferably be generated in a frame structure. Thereafter, the integrated control message is broadcast to a plurality of underwater robot 130 after the encryption process.

4 is a flowchart illustrating a remote control method of a plurality of underwater robots according to an embodiment of the present invention.

In FIG. 4, a plurality of underwater robots R1, through a process of transmitting and receiving messages with the plurality of underwater robots R1, R2, and R3 using a sonic signal at the gateway G / W according to an embodiment of the present invention. A method of remotely controlling R2, R3) is shown.

As shown in FIG. 4, the gateway G / W generates a preamble message 410 in the advertisement section 210 of the initialization section 200 and generates a plurality of preamble messages at predetermined time intervals. Broadcast to the underwater robot (R1, R2, R3) (S101). As a result, the underwater robots R1, R2, and R3 receive the broadcast preamble message 410 thus broadcasted in the joining section 220, respectively, to select a cluster to join each other, and to join the selected cluster. Create a join message including the location information of the transmission to the gateway (G / W) (S103).

Thereafter, the gateway G / W generates a beacon frame in the beacon section 230 and broadcasts it to the plurality of underwater robots R1, R2, and R3 (S105). Using the beacon frame, time slots for data transmission for each underwater robot R1, R2, and R3 are allocated according to the location information of each underwater robot R1, R2, and R3. Subsequently, the underwater robots R1, R2, and R3 transmit the underwater information collection data 420 to the gateway G / W through the timeslot 241 allocated in the control section 240 (S107).

At this time, the ground node 110 may transmit a control message for the underwater robot (R1, R2, R3) aperiodically through the gateway (G / W). In this case, the gateway G / W buffers the control messages for each underwater robot R1, R2, and R3 received aperiodically from the ground node 110 in the data transmission section 250 for a predetermined time, and then integrates them. Through the process of merging, an integrated control message is generated and converted into an encrypted message (blocked message) 430 and broadcasted to a plurality of underwater robots R1, R2, and R3 (S109).

After that, the gateway G / W continuously broadcasts a new beacon frame to the underwater robots R1, R2, and R3 at the next control section (S111), and the underwater robots R1, R2, and R3 are at their positions. The collected information and the underwater information are transmitted to the gateway G / W through its time slot (S113). The location information is for periodically notifying the change of position according to the movement of each underwater robot (R1, R2, R3).

5 is an exemplary diagram of a network topology when a new underwater robot enters into a cluster according to another embodiment of the present invention.

5 illustrates a plurality of clusters A, B, C, and D according to another embodiment of the present invention. Each cluster A, B, C, and D includes a gateway G / W and a plurality of underwater robots R1 to R11. At this time, it is natural that the number of underwater robots can be changed for each cluster.

Underwater robots R1 to R11 are guaranteed mobility so that they can enter another cluster from the cluster they belong to during the mission. For example, there is shown an example in which the underwater robot R4 leaves the existing cluster C and enters another cluster A. In this case, the underwater robot R4 initially performs underwater communication with the gateway GW2 belonging to the cluster C, and later performs underwater communication with the gateway GW1 belonging to the newly entered cluster A.

6 is a flowchart illustrating a remote control method of the underwater robot according to another embodiment of the present invention in FIG. 5.

In FIG. 6, when a new underwater robot R4 enters a cluster according to another embodiment of the present invention, the gateway 120 transmits and receives a message to and from a plurality of underwater robots 130 using a sonar signal. A method of remotely controlling a number of underwater robots 130 is shown.

5 and 6, the gateways G / W1 and G / W2 according to another embodiment of the present invention generate a preamble message in the advertisement section 210, and the clusters to which the gateways belong to each other at preset time intervals. Broadcast to underwater robots R1, R2, R3, R4, R5, and R6 in (A, C). That is, in the example of the drawing, in the cluster A, the first robot G / W1 to the underwater robots R1, R2, and R3, and in the cluster C, the underwater gateway R4 in the second gateway G / W2. Broadcast a preamble message with R5 and R6). Accordingly, each of the underwater robots R1 to R6 receives the preamble message broadcasted in this way in the joining section 220, selects clusters to join each of them, and joins the selected clusters to join the selected clusters. The join message including the location information is transmitted to the gateways G / W1 and G / W2.

Thereafter, the first gateway G / W1 generates a beacon frame and broadcasts it to the underwater robots R1, R2, and R3 in the cluster A to which the first gateway G / W1 transmits data for each underwater robot R1, R2, and R3. Allocate the time slots for each of the underwater robots (R4, R5 and R5) by generating beacon frames in the second gateway (G / W2) and broadcasting them to the underwater robots (R4, R5, R6) in the cluster (C) to which they belong. In operation S201, a time slot for data transmission is allocated according to the location information of R 6. Afterwards, each of the underwater robots R1 to R6 transmits the underwater information collection data to the corresponding gateways G / W1 and G / W2 through the timeslot 241 allocated in the control section 240 (S203).

Subsequently, each gateway G / W1 and G / W2 generates a control message for each underwater robot R1 to R6 received aperiodically from the ground node 110 in the data transmission section 250 as an integrated control message. Then, it is converted into an encrypted message (BM: blocked message) and broadcasted to the respective underwater robots R1 to R6 (S205).

Subsequently, when the specific underwater robot R4 leaves the existing cluster C and enters the new cluster A, the first gateway G / W1 may determine the beacon frame in the next control section 240. By broadcasting to the underwater robots R1, R2, R3, and R4 in the cluster A, time slots for data transmission for each underwater robot R1, R2, R3, and R4 are allocated (S207). Then, in the control section 240, the existing underwater robots R1, R2, and R3 transmit the underwater information collection data to the first gateway G / W1 (S209), and the first gateway in the data transmission section 250. (G / W1) converts the integrated control message of each underwater robot (R1, R2, R3) received aperiodically from the ground node (110) into an encrypted message (BM: blocked message) to convert the respective underwater robot ( Broadcast to R1, R2, R3 (S211).

Thereafter, the specific underwater robot R4 entering into the new cluster A in the maintenance / sleep section 260 receives a beacon frame received in step S207 and issues a join message for joining its cluster A. FIG. It transmits to one gateway G / W1 (S213). Accordingly, in the next control section 240, the first gateway G / W1 transmits a beacon frame to the underwater robots R1, R2, R3, and R4 in its cluster A, and each underwater robot R1. , R2, R3, and R4 transmit the underwater information collection data and the location information to the first gateway G / W1 through the timeslot assigned thereto (S215). Through these processes, the underwater robot R4 participates in the new cluster A and transmits and receives data with the first gateway G / W1.

Meanwhile, since the underwater robot R4 is moved to another cluster in step S207, only the existing underwater robots R5 and R6 are not received because the underwater robot R4 does not receive the beacon frame broadcasted by the second gateway G / W2. Data is transmitted and received with the second gateway G / W2.

7 is an exemplary diagram of a network topology for a case where an underwater robot moves in a cluster according to another embodiment of the present invention.

In the example cluster of FIG. 7, the distance from the gateway (G / W) 120 to the underwater robots R1, R2, and R3 130 is in the order of R3>R2> R1. Subsequently, when the underwater robots R1, R2, and R3 move as shown in the cluster on the right, the distance from the gateway G / W to the respective underwater robots R1, R2, and R3 is in the order of R2>R3> R1. . Of course, this order is an example and the order of the distances can be changed.

FIG. 8 is a flowchart illustrating a method for remotely controlling an underwater robot according to still another exemplary embodiment of the present disclosure in FIG. 7.

In FIG. 8, when a specific underwater robot 130 moves according to another embodiment of the present invention, a gateway (G / W) 120 transmits and receives a message to and from a plurality of underwater robots 130 using a sonar signal. A method of remotely controlling a plurality of underwater robots (R1, R2, R3) 130 through the process is shown.

7 and 8, the gateway G / W according to another embodiment of the present invention generates a preamble message in the advertisement section 210, and at each preset time interval, the underwater robot in the cluster to which it belongs. Broadcast to (R1, R2, R3). Thus, each of the underwater robots R1, R2, and R3 receives the preamble message broadcasted in the join section 220 and transmits the join message to the gateway (G / W) to join the cluster.

Thereafter, the gateway G / W generates a beacon frame and broadcasts it to the underwater robots R1, R2, and R3 in the cluster, thereby transmitting data according to the location information of each of the underwater robots R1, R2, and R3. Allocates a slot (S301). At this time, these timeslots are assigned sequentially according to the distance of each underwater robot (R1, R2, R3). For example, in the left cluster of FIG. 7, timeslots are allocated in the order of R1, R2, and R3. Accordingly, the underwater robots R1, R2, and R3 sequentially transmit the underwater information collection data to the gateway G / W through the time slot 241 assigned to the control section 240 (S303).

Subsequently, the gateway G / W merges the control messages for the underwater robots R1, R2, and R3 aperiodically transmitted from the ground node 110 in the data transmission section 250 to form an integrated control message. It generates and converts it into an encrypted message (BM: blocked message) and broadcasts it to underwater robots R1, R2, and R3 (S305).

Subsequent S307 to S311, the gateway G / W broadcasts the beacon frame to the underwater robots R1, R2, and R3, and the underwater robots R1, R2, and R3 locate the gateway G / W. And transmits the underwater information collection data and broadcasts the integrated control message encrypted at the gateway G / W to the underwater nodes R1, R2, and R3.

Here, when the distances of the underwater robots R1, R2, and R3 are changed, that is, changed to R2> R3> R1, as shown in the right cluster of FIG. 7, the beacon frame is changed to the underwater robots R1 and R2. Broadcasts to R3), and changes the order of time slots according to the changed position information of each of the underwater robots R1, R2, and R3 (S313). That is, time slots are sequentially assigned according to the distance of each underwater robot R1, R2, R3. For example, in the right cluster of FIG. 7, timeslots are allocated in the order of R1, R3, and R2. Accordingly, the underwater robots R1, R2, and R3 sequentially receive the underwater information to the corresponding gateway G / W according to the order R1-R3-R2 of the timeslot 241 allocated to the underwater robot R1, R2, and R3. The collected data is transmitted (S315).

While the invention has been shown and described with reference to certain preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the appended claims, The genius will be so self-evident. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Recently, as the development of marine resources is required, research and development on underwater communication technology is actively progressing. Such underwater communication technology is expanding to various fields. Recently, underwater communication technology is also being considered as a plurality of applications are converged. In particular, by incorporating mobile robots into the underwater environment, it is possible to collect more information in a wider area.

Accordingly, in this convergence field, a plurality of underwater robots require aperiodic remote control of the underwater robots. In this aspect, the present invention can be very useful in the field of underwater resource development because it can control a plurality of underwater robots in a remote place aperiodically in the remote environment.

110: ground node 120: gateway (G / W)
130: underwater robot 200: initialization section
210: advertising section 220: signing section
230: beacon section 240: control section
250: Data transmission section 260: Maintenance / sleep section
270: Super frame section

Claims (19)

Broadcasting a preamble message to a plurality of underwater robots in a cluster to which the gateway belongs in the advertisement section of the underwater communication protocol;
Selecting a cluster to join each of the plurality of underwater robots in a join section of the underwater communication protocol, and transmitting a join message including request information for joining the selected cluster and location information thereof to the gateway;
Allocating a beacon frame to the plurality of underwater robots in the beacon section of the underwater communication protocol in the gateway and allocating a time slot for data transmission according to the location information of the underwater robot;
Transmitting, by the underwater robot, the underwater information collection data to the gateway through time slots respectively allocated in the control section of the underwater communication protocol; And
Broadcasting, at the gateway, a control message for the underwater robot received from an upper node in the data transmission section of the underwater communication protocol to the plurality of underwater robots; Including,
The step of assigning the timeslot, remote control of the underwater robot, the time slots are assigned in the order that the distance from the gateway to the underwater robot using the position information of the underwater robot included in the join message Way. delete The method of claim 1,
And remotely receiving a control message for the underwater robot from the upper node in the gateway. The method of claim 3,
Broadcasting a control message for the underwater robot,
Buffering a control message for each of the underwater robots aperiodically transmitted from the upper node at the gateway for a preset time;
Merging the buffered control message to produce one unified control message;
Encrypting the integration control message; And
Broadcasting the encrypted integrated control message to the plurality of underwater robots; Remote control method of the underwater robot comprising a. The method of claim 1,
When a new underwater robot enters into the cluster and receives a beacon frame broadcast from the gateway, the new underwater robot receives subscription request information and its location information for joining the cluster in the maintenance / sleep period of the underwater communication protocol. The remote control method of the underwater robot further comprising the step of transmitting a join message including a. The method of claim 5,
At the gateway, broadcasting a beacon frame to a plurality of underwater robots including the new underwater robot in a beacon section of the next period of the underwater communication protocol and allocating a time slot according to the location information of each underwater robot; And
Transmitting underwater information collection data to the gateway through the allocated timeslot in a control section of a next period of the underwater communication protocol in a plurality of underwater robots including the new underwater robot; Remote control method of the underwater robot, characterized in that it further comprises. The method according to claim 6,
And broadcasting, by the gateway, the plurality of underwater robots including the new underwater robot, the control messages for each of the underwater robots aperiodically transmitted from the upper node in the data transmission section of the next period of the underwater communication protocol. Remote control method of the underwater robot, characterized in that. The method of claim 7, wherein broadcasting to the plurality of underwater robots,
Buffering the control message for each underwater robot at the gateway;
Merging the buffered control message to produce one unified control message;
Encrypting the integration control message; And
Broadcasting the encrypted integrated control message to a plurality of underwater robots, including the new underwater robot; Remote control method of the underwater robot comprising a. The method of claim 1,
When the plurality of underwater robots move their positions and the distance to the gateway is changed, transmitting a join message including their location information to the gateway in a join section of the underwater communication protocol by the plurality of underwater robots; And
At the gateway, broadcasting a beacon frame in the beacon section of the underwater communication protocol to the plurality of underwater robots and allocating a time slot according to the changed position information of the underwater robot; And
Transmitting the underwater information collection data to the gateway through the allocated timeslot in the control section of the underwater communication protocol in the plurality of underwater robots; Remote control method of the underwater robot, characterized in that it further comprises. 10. The method of claim 9, wherein assigning the timeslots comprises:
And assigning time slots in the order of close proximity to the underwater robot from the gateway by using the changed position information of the underwater robot included in the join message. 10. The method according to claim 6 or 9,
The underwater robot, which does not need to be assigned the timeslot, operates in a sleep mode in a maintenance / slip section of the underwater communication protocol and maintains the inactive state. In the advertisement section of the underwater communication protocol, broadcast a preamble message into the cluster to which it belongs, and broadcast the beacon frame into the cluster in the beacon section of the underwater communication protocol to allocate a time slot for data transmission. A gateway for broadcasting a plurality of control messages received in a data transmission section into the cluster;
In the join section of the underwater communication protocol, each of the clusters to which it joins is selected, and a join message including request information and its location information for joining the selected cluster is transmitted to the gateway, and the control section of the underwater communication protocol A plurality of underwater robots for transmitting the underwater information collection data to the gateway through the assigned timeslot; And
An upper node for aperiodically transmitting the plurality of underwater robot control messages to the gateway through a wireless network; Including,
The gateway assigns time slots in order of close proximity to each of the underwater robots using the location information of the underwater robots included in the join messages received from the plurality of underwater robots. Remote control system. delete The method of claim 12, wherein the gateway,
The plurality of underwater robot-specific control messages received from the upper node are buffered for a predetermined time and merged the buffered control messages into a single integrated control message, and the integrated control message is generated. The remote control system of the underwater robot, characterized in that for encrypting and broadcasting to the plurality of underwater robots. The method of claim 12,
When a new underwater robot enters into the cluster and receives a beacon frame broadcast from the gateway, the new underwater robot receives subscription request information and its location information for joining the cluster in the maintenance / sleep period of the underwater communication protocol. Remote control system of the underwater robot, characterized in that for transmitting a join message including the gateway. 16. The method of claim 15,
The underwater communication protocol is a remote control system of the underwater robot consisting of a frame comprising an initialization section consisting of the advertising section and the join section, and a super frame section consisting of the control section, data transmission section and maintenance / sleep section. . The method of claim 12,
When the plurality of underwater robots move their positions and the distance from the gateway is changed, the plurality of underwater robots transmit a join message including their location information to the gateway in the join section of the underwater communication protocol, and at the gateway Broadcasting a beacon frame to the plurality of underwater robots in the beacon section of the underwater communication protocol, the remote control system of the underwater robot, characterized in that to allocate a time slot according to the changed position information of the underwater robot. Forming, at the gateway, an advertisement section for broadcasting the preamble message to a plurality of underwater robots in a cluster to which the gateway belongs;
Selecting a cluster to be joined by the plurality of underwater robots and forming a join section for transmitting a join message including request information for joining the selected cluster and location information thereof to the gateway;
The gateway generates a beacon frame including the plurality of underwater robot information and timeslot allocation information and broadcasts the information to the plurality of underwater robots to allocate time slots for data transmission according to the position information of the underwater robot. Forming;
Forming a control section for transmitting the underwater information collection data to the gateway through timeslots allocated by the plurality of underwater robots;
Forming a data transmission section for broadcasting the underwater robot control message received aperiodically from an upper node in the gateway to the underwater robot; And
When the new underwater robot enters into the cluster, forming a maintenance / sleep section for transmitting a join message including subscription request information and location information for joining the cluster from the new underwater robot to the gateway; Method of forming an underwater communication protocol for remote control of the underwater robot comprising a. 19. The method of claim 18,
In the data transmission section, the gateway buffers the plurality of underwater robot-specific control messages received from the upper node periodically for a predetermined time and merges the buffered plurality of control messages into one integrated control message. And encrypting the integrated control message and broadcasting to the plurality of underwater robots, wherein the underwater communication protocol for remote control of the underwater robot is generated.

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