KR101980644B1 - Data process method to support multiple data comunication - Google Patents

Abstract

The present invention provides a data processing method for processing internal data and external data in different paths wherein a data processing method is for manipulation control of multiple unmanned aerial vehicles with a single ground control system (GCS) using a data processing apparatus. The data processing apparatus comprises: a process unit including a message processing unit, a packet data processing unit, and a MAC frame processing unit for processing the external data transceived with the unmanned aerial vehicle and the internal data to control the unmanned aerial vehicle; and an interface unit including a virtual network interface (VNI), a libpcap interface (LPI), and a network interface (NI) to set a path of the internal data and the external data.

Description

Technical Field [0001] The present invention relates to a data processing method for supporting multiple data communication,

The present invention relates to a data processing method for supporting multiple data communication schemes such as IP-based traffic data communication and socket communication.

The Platform Centric Warfare (PCW) environment, which used to be the dominant factor in the battle for the victory of the war through its powerful firepower, is a network center that brings battle victory through sharing real-time battlefield information through surveillance and reconnaissance information between combat elements. Network Centric Warfare (NCW). As a factor for NCW realization, surveillance and reconnaissance system plays an important role. And among the ground / maritime / public surveillance reconnaissance systems, the public surveillance and reconnaissance system, which has high mobility and excellent surveillance ability over a wide area, is the core of NCW. Among the public surveillance and reconnaissance systems, UAVs are becoming increasingly important because of their capability of sharing battlefield situations and high-precision hits through surveillance and reconnaissance. The unmanned aerial vehicle (UAV) system, which is mainly focused on UAVs, performs surveillance and reconnaissance missions in the air, and manages unmanned aerial vehicles (UAVs) that act as sensors and manages UAVs on the ground. And a Ground Control System (GCS). The UAV and ground control system send and receive data collected during the surveillance mission such as Tc (Telecommand) to control the UAV, Tm (Telemetry) including the location, status and performance of the UAV, and images and images. , Data Link (Data Link) is a digital communication technology that enables communication between UAV and ground control system.

Data links operating in unmanned aircraft systems are based on the Common Data Link (CDL), which is capable of transmitting Tc and Tm data based on the STANAG 4586 standard and collecting data such as images and images. MPL-CDL (Multi-Platform CDL), which is a typical public data link, has been developed in the US and MPI-CDL (Multi-Platform Image and Intelligence CDL) has been developed in Korea. Unmanned data link ensures UAV control information delivery time through quality of service (QoS) in narrow frequency band as well as large data transmission, and it can control and operate many UAVs with IP based 1: N communication structure. .

Data link communication equipment operated to support a 1: N communication structure in a narrow frequency band requires processing that reflects characteristics of each data type. Since Tc and Tm data are data for UAV control, they are small in size but high in importance, so it is necessary to guarantee transmission time together with priority processing through QoS guarantee. On the other hand, video data requires faster delivery so that playback delay is minimized because real-time situation sharing is more important than data transmission guarantee. In addition, it is necessary to be able to route the Tc and Tm data communicating with the data communicating with the unmanned equipment having the IP address such as the camera and the sensor equally mounted on several UAVs and the socket type.

Data link communication equipment for multi-UAV control requires data processing structure that reflects the characteristics of each data and communication structure, and the following functions should be reflected in design considering these characteristics. First, it is necessary to guarantee transmission time of Tc and Tm data and to transmit / receive by dividing into a wired section and a data link section. Since Tc and Tm data are information for UAV control, it is necessary to guarantee a predetermined transmission time irrespective of the frequency bandwidth and data amount of the data link section. In addition, it is necessary to receive and transmit the data coming into the wired section and the data coming into the wireless section through the data link in a socket manner in accordance with the UDP / IP communication method defined in STANAG 4586 standard. Second, the external transmission data transmitted and received by the UAV and the internal transmission data such as Tc and Tm should be able to be routed based on the destination IP address. The data transmitted by the GCS can have the same number of different destination addresses as the UAV, and after receiving by the data link communication equipment, it can quickly identify the interworking interface so as to minimize the propagation delay along with route setting corresponding to the destination address Be able to deliver. Third, it is necessary to guarantee the data rate by data type through QoS guarantee. Even if data exceeding the bandwidth allocated to the image data occurs, the Tc and Tm data must be transmitted in accordance with the determined transmission rate without being affected, and the image data must be processed in accordance with the determined transmission rate. In this way, the data link communication equipment for multi-UAV control should be designed considering characteristics of 1: N communication method and data processing structure.

Korean Patent No. 10-1355676 Korean Patent No. 10-1846227

The present invention provides a data processing method for supporting multiple data communication capable of controlling and controlling multiple unmanned vehicles by using one ground control system.

The present invention provides a data processing method for supporting multiple data communication that reflects functional features to be considered in designing a data link communication equipment.

A data processing method according to an embodiment of the present invention includes a processing unit including a message processing unit, a packet data processing unit, and a MAC frame processing unit for processing external data transmitted and received by the UAV and internal data for controlling the UAV, And an interface unit including VNI, LPI, and NI to set a path of external data, wherein the external data includes an LPI, a packet data processing unit, and a MAC And the internal data is transmitted and received through a message processing unit, a VNI, a packet data processing unit, and a MAC frame processing unit. The internal data is transmitted from the UAV to the GCS including the status, performance, and location information of the UAV. Tm data and UAV flight control, The external data includes Tc data received from the GCS for GDC and GDC, and the external data is processed by ARP or DISK based on the IP address and then converted into MAC frame data and transmitted through the data link. And transmits the received external data to the UTRAN through the ARP or DISK processing based on the IP address and transmits the external data to the UTRAN. A process of performing an ARP request and response when it is judged that the data is not valid data, a process of comparing the destination of the data or the destination IP address with the NI address in case of valid data, or if the subnet check fails, , The destination or destination IP address and the NI address are not the same, and the subnet check The method comprising the steps of: if the destination IP address and the NI address of the packet data received from the GCS do not match, extracting the subnet of the destination IP address Checking the MAC address corresponding to the destination IP in the ARP table if the subnet check is successful; and generating an Ethernet header when the MAC address search is successful, Adding the data to the data and transmitting the data through the LPI; and if the MAC address search fails, performing the ARP request and response to the destination IP address according to the ARP transmission procedure.

The receiving of the external data further includes determining the internal data if the destination IP address and the NI address of the packet data received from the GCS are the same.

The internal data is received by comparing the destination IP address and the NI address of the packet data and if they are the same, changing the destination IP address to the VNI address, recalculating the IP check sum according to the IP header value change, A step of storing destination information by analyzing the IP address of the destination IP address, and a step of checking if the destination IP address and the destination address of the packet data are not the same by checking the subnet of the destination IP address, Transmitting to the LAN section through the LPI, and dis- card processing if not confirmed.

The internal data transmission process includes generating internal data from the GCS address information stored in the internal data receiving process, re-calculating the IP checksum after changing the IP address of the internal data to the NI address, And converting the packet-classified internal data into MAC frame data, and transmitting the MAC frame data through the data link.

A data processing apparatus and method according to embodiments of the present invention can transmit Tc and Tm data based on a User Datagram Protocol (UDP) / Internet Protocol (IP) based on a data link section and a wire section, A virtual network interface (VNI) is applied to guarantee the transmission time and the image data distributed on the same path can be quickly transmitted to the destination. Also, it is possible to guarantee QoS by data type through data type classification.

According to the present invention, even if the load of the packet data transmission / reception processing increases, the data transmission time can be maintained within a certain range without abrupt change. That is, even if the traffic of the data link section increases in a plurality of UAVs, the transmission time of Tc and Tm can be guaranteed in a predictable range. Therefore, by using the data processing apparatus and method according to the present invention, a plurality of UAVs can be more efficiently controlled and controlled by using one ground control system.

FIG. 1 is a schematic view showing an interworking structure of a UAV's data link communication equipment; FIG.
2 is a schematic diagram showing an IP network structure of a multi-UAV and a GCS;
3 is a block diagram for explaining a data processing apparatus according to an embodiment of the present invention;
4 is a schematic view for explaining a flow of external data according to an embodiment of the present invention;
5 and 6 are flowcharts of a method of transmitting and receiving external data according to an embodiment of the present invention.
7 is a schematic diagram for explaining a queue structure for each data type;
8 is a schematic diagram for explaining a flow of internal data according to an embodiment of the present invention;
9 and 10 are flowcharts of a method of transmitting and receiving internal data according to an embodiment of the present invention.
11 is a schematic diagram according to an experimental example of the present invention.
12 to 14 are graphs showing experimental results of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely. In the drawings, the thickness is enlarged to clearly illustrate the various layers and regions, and the same reference numerals denote the same elements in the drawings.

Ⅰ. UAV data link

1. UAV configuration

The common data link was developed for the purpose of applying surveillance and reconnaissance system that is carried out through UAV with multi - purpose digital communication technology based on the existing analog communication method and other wireless link. In the unmanned aerial vehicle system operation based on the public data link, a technique that minimizes the disconnection as much as it can cause the failure of the mission or the loss of the UAV during the data link disconnection is applied. A communication is configured in a non-line-of-sight environment through a relay device such as a satellite, or a data link is duplicated in a line-of-sight environment in a primary link and a secondary link. The first link of the line-of-sight communication is intended to transmit a large-capacity surveillance and reconnaissance information (ISR) such as images and images collected through surveillance and reconnaissance. For this reason, And a high transmission rate. On the other hand, the secondary link is intended for UAV control so that the duty of the UAV can be maintained or returned when the primary link is disconnected, and transmission of Tc, Tm data and small image for UAV control is performed. Also, since the secondary link performs communication with a narrow frequency resource unlike the primary link, it aims to communicate with a UAV in the line of sight through an omnidirectional antenna that does not require additional antenna tracking. The present invention proposes a data processing method capable of controlling and controlling multiple UAVs in a secondary link environment.

2. UAV data link communication equipment configuration

Unmanned data link communication equipment operated by a secondary link has characteristics different from general communication equipment and data processing method. Devices such as cameras and sensors mounted on UAVs are assigned IP addresses and perform IP communication as host devices. Since a small local area network (LAN) is constructed within the UAV, it is necessary to manage the media access control address (MAC address) of the equipments mounted on the UAV and to process the route setting and transmission data based on the destination IP address. In addition, it should be able to interwork through data conversion so that data communication can be performed with other communication methods other than IP and modules inside a communication device connected to the medium. FIG. 1 shows an interworking structure of a UAV's data link communication equipment. In the UAV, there are provided equipment such as a camera and a sensor, and communication equipment including a plurality of modules is provided. As shown in FIG. 1, the Tc information received from the GCS must be converted into a communication method and medium capable of receiving the module in the communication equipment, and transmitted, and the information of the UAV must be converted into Tm and transmitted to the GCS . A data processing structure capable of efficiently processing this will be described in detail.

Ⅱ. Data processing apparatus and method

1. Data processing device

Prior to the implementation of the data processing apparatus according to the present invention, the IP network of the data link including the GCS and N UAVs is designated as Class C, and a different subnet is assigned to each GCS and UAV. FIG. 2 is a schematic diagram showing an IP network structure of a multi-UAV and a GCS. As shown in FIG. 2, a LAN can be configured for each UAV by assigning different subnets to a plurality of UAVs. IP address assignment can be simplified by specifying a host IP address, so that it is easy to manage IP addresses and can be expanded. If the host IP of the camera is set to 20, the camera of UAV # 1 can be assigned and managed as 192.168.1.10, and the camera of UAV # 2 can be assigned and managed as 192.168.2.10. This has the merit of being able to cope easily even when new host IP allocation is required owing to the addition of UAV equipment for surveillance and reconnaissance.

The data processing apparatus according to an embodiment of the present invention may include three applications and three kernel interfaces as shown in FIG. The data processing apparatus of the present invention can be used to divide the internal transmission data for controlling the Tc and Tm into the UTRAN and the external transmission data transmitted and received in the UAV. The application includes a message processing unit 110 for processing Tc and Tm data, a packet data processing unit (PDP) 120 for processing packet data, a MAC frame generating / restoring unit 120 for transmitting / And a MAC Frame Processor (MFP) 130. The message processor 110 may include, for example, a STANAG 4586 Message Process (STMP) process for processing Tc and Tm data of the STANAG 4586 standard using a socket communication method. The kernel interface includes a virtual network interface (VNI) 210 based on a tun driver for allowing internal transmission data of Tc and Tm to be communicated in a socket manner, And a LibPcap Interface (LPI) 220 based on a cap (libpcap). In addition, the kernel interface may further include a network interface (NI) Meanwhile, the data processing apparatus of the present invention may further include a NIC (Network Interface Card) 310 at a physical level.

The data can be divided into data that need to be distributed to the LPI 220 and the VNI 210 from the viewpoint of data processing, and data transmission / reception time points for each interface can be classified as follows.

LPI transmission data: Data that needs to be transmitted in the data link section. It is used to transmit image data or sensor data

LPI receive data: The data received in the data link section, the data to be transmitted from the GCS for control of the UAV

VNI transmission data: Tm data including data of UAV that needs to be transmitted in the data link section, UAV, which requires transmission from UAV to GCS

VNI receive data: Data received in the data link section, Tc data to be transmitted from GCS to UAV for the purpose of UAV flight control,

The LPI 220 and the VNI 210 process data in the form of an IP packet without an Ethernet header and perform transmission and reception such that packet data can be distributed based on an IP address as in the operation of a network layer. Meanwhile, the message processing unit 110 and the packet data processing unit 120 process data received from the LPI 220, the VNI 210, and the MAC frame processing unit 130. The message processing unit 110 processes the internal transmission data in a UDP / IP socket manner, and the packet data processing unit 120 processes external transmission data in cooperation with the MAC frame processing unit 130. Functions of each processing unit will be described as follows.

The message processor 110 transmits and receives STANAG data using a GCS and a UDP / IP socket communication method and transmits and receives socket data of a data link section through a VNI 210 and a network interface (NI) The socket data of the LAN section is processed as one socket.

The packet data processing unit 120 transmits an ARP or a Discard packet based on the IP address to the packets received from the VNI 210, the LPI 220 and the MAC frame processing unit 130. [ . The packet data processing unit 120 also performs a data forwarding process to the MAC frame processing unit 130, the LPI 220, and the VNI 210. The data to be transmitted to the MAC frame processing unit 130 is subjected to data classification and queue input so that QoS can be guaranteed.

The MAC frame processing unit 130 converts a packet received from the packet data processing unit 120 into a MAC frame for transmission and reception of data through a data link and transmits the converted data to a packet, And transfers the packet data to the packet data processing unit 120. That is, the MAC frame processing unit 130 of the UAVs receives data transmitted from the UAV to the GCS by the packet data processing unit 120, converts the data into MAC frames, restores data received from the GCS to the UAV, And transmits them to the packet data processing unit 120. [

Meanwhile, since the MAC frame processing unit 130 for processing packet data and processing for generating and restoring MAC frames may generate a large number of loads, the asymmetric multiprocessing A CPU on which the message processing unit 110 and the packet data processing unit 120 are executed is called a master and a CPU on which the MAC frame processing unit 130 is executed is remotely operated Remote).

In order to process the external transmission data in such a data processing apparatus and maintain the internal transmission data transmission time of Tc and Tm within a certain range, data interlocking and processing of the packet data processing unit 120 and the VNI 210 are very important. Such a data processing apparatus may be provided in a UAV. The data processing apparatus may also be provided in the GCS. That is, the data processing apparatuses of the same structure are provided in the UAV and the GCS, so that the external data or the internal data are moved between them. In the following, a data interlocking method for processing internal transmission data and external transmission data and its implementation will be described.

2. How to handle external data

In order to process the data transmitted from the UAV, the packet data processing unit 120 processes the LPI 220 and transmits the packet to the data link section. The image data transmitted from the UAV has the GCS IP address as the destination address. The GCS is located in a network having different subnets as shown in FIG. 2. In this structure, in order to transmit to a GCS having a different subnet, an IP address assigned to a data link communication apparatus is allocated to a gateway address Is required. The LPI 220 is activated in an anonymous mode to capture all packets coming into the NIC 310. In the anonymous mode, a packet transmitted through the NIC 310 is also captured. The packet data processing unit 120 processes the received packet. The data to be transmitted to the GCS from the onboard device is captured by the LPI 220 and transferred to the packet data processing unit 120. On the contrary, the data transmitted from the GCS for the onboard equipment control is transferred from the data processing unit 120 to the LPI 220 to be transmitted to the mounting equipment. The external data transmission flow transmitted from the onboard equipment to the GCS and the external data reception flow received from the GCS for the onboard equipment control are shown in FIG. 4, the external data transmission processing method is shown in FIG. 5, The reception processing method is shown in Fig. 4 and 5 illustrate a data flow in a UAV and a GCS according to the transmission and reception of external data. FIGS. 5 and 6 are flowcharts for explaining a processing method, that is, a control method, Respectively. In FIG. 4, the same reference numerals are assigned to the same components in order to distinguish the data processing apparatus of the UAV and the data processing apparatus of the GCS.

4, the external data transmitted from the UAV to the GCS is input to the GCS through the data link via the LPI 221, the packet data processing unit 121, and the MAC frame processing unit 131 of the UAV. Here, the packet data processing unit 121 performs ARP or DISK processing on the packet received through the LPI 221 based on the IP address, and then forwards the packet to the MAC frame processing unit 131. The MAC frame processing unit 131 processes the packet And converts the packet received from the data processing unit 121 into a MAC frame so that the packet can be transmitted through the data link. The GCS receives the data input from the UAV through the data link to the LPI 222 through the MAC frame processing unit 132 and the packet data processing unit 122, and then transfers the data to the user interface. Here, the MAC frame processing unit 132 restores the MAC frames input through the data link into packets, separates the data according to data types, and transmits the packetized data to the packet data processing unit 122. The packet data processing unit 122 includes a MAC frame processing unit 132 And then forwards the packet to the LPI 222 after processing the ARP or DISCARD based on the IP address.

4, the external data received by the UAV from the GCS for control of the onboard equipment is input to the packet data processing unit 120 through the LPI 220 of the GCS, And then inputted to the MAC frame processing unit 130, converted into a MAC frame, and then input into the URI through the data link. In the UAV, the data received from the GCS via the data link is transferred to the LPI 220 through the MAC frame processing unit 130 and the packet data processing unit 120, and then transferred to the mounting equipment.

As described above, external data of the UAV is provided through the LPI 221 and the NIC 311. That is, the external data is not transmitted / received through the VNI 211 and the message processing unit 111, but is transferred to the packet data processing unit 121 through the LPI 221 or to the LPI 221 through the packet data processing unit 121 .

2.1 External Data Transmission Processing

FIG. 5 is a flowchart for explaining a data processing method according to an embodiment of the present invention, and is a flowchart for explaining a process of transmitting external data to a GCS in a UAV. That is, FIG. 5 is a flowchart of a data processing method for transmitting external data from the data processing unit of the UAV to the GCS.

First, it is determined whether the data transmitted from the onboard device is valid data based on the IP address (S101). That is, when transmission data is input to the packet data processing unit 120 through the LPI 220 in the UAV, the packet data processing unit 120 determines whether the data is valid based on the IP address.

As a result of the determination, if it is not valid data, it is confirmed whether it is ARP request data (S102). That is, it confirms whether it is ARP request data to be transmitted in the broadcast method before transmitting data to the GCS from the onboard equipment. If it is confirmed that the data is ARP request data, an APR response message is transmitted (S103). Otherwise, it is confirmed whether the data is ARP response data (S104). In the case of the ARP response data, an ARP node is added (S105), and if it is not the ARP response data, a diskette process is performed (S106).

As a result of the determination, if it is valid data, the MAC frame processing unit 130 forwards or discards the processed data (S107 to S111). The DISCARD condition is that the destination or destination IP address is the same as the NI address. That is, it is determined whether the transmission destination or the destination IP address is the same as the NI address (S107). A packet having the same destination IP address can be regarded as a captured packet transmitted from the data link communication device to the LAN section, and a packet having the same destination IP address can be regarded as socket data transmitted to the message processing section 110 through the LAN section. .

If the destination or destination IP address is not the same as the NI address, it is processed according to the result of the subnet check (S109). If the destination or destination IP address is not identical to the NI address, the MAC frame processing unit 130 (S111). The packets forwarded to the MFP are input to the AMP queue for each data type through packet classification as shown in FIG. The input data is designed to guarantee the transmission time to the destination according to the transmission rate assigned to each data. In addition, the packets to be input to the queue are formed as IP packets except for the Ethernet header, thereby reducing the packet size by at least 10%, thereby improving the transmission efficiency of the data link section having a narrow bandwidth.

2.2 External Data Reception Processing

FIG. 6 is a flowchart for explaining a data processing method according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating a process of receiving external data from a GCS. That is, FIG. 6 is a flowchart of a data processing method for receiving external data from the GCS in the data processing unit of the UAV.

The destination IP address of the packet received from the MAC frame processing unit 130 is checked to determine whether it is the same as the IP address of the NI (S201). If it is the same, it is determined that the Tc data is required to be transmitted to the message processing unit 110, and the Tc data is transmitted to the VNI 210.

A packet whose destination IP address is different but whose subnet is the same as the IP address of NI can be determined as data for controlling the onboard device, and transmission processing to the LAN section is required. First, it is checked whether the UAV is data of the UAV by checking the subnet of the destination IP address (S203). If it is confirmed, the MAC address corresponding to the destination IP is searched in the ARP table (S204). If the MAC address search is successful, an Ethernet header is generated based on the information (S205), an Ethernet header is added to the packet (S206), and the packet is transmitted to the LAN section through the LPI (S207) and the NIC (310).

If the MAC address search corresponding to the destination IP is unsuccessful in the ARP table, an ARP request is transmitted to the destination IP address in accordance with the ARP transmission procedure and the ARP response is received (S209). When the ARP response is normally received, the MAC address of the mounted device is updated in the ARP table (S210), and the packet is transmitted to the NIC to finally transmit the packet to the mounted device. Conversely, when an ARP request retry is exceeded or a timeout occurs, a dis- card is performed (S208).

3. Internal transmission data processing structure

The VNI 210 enables the transmission of the Tc and Tm data received from the GCS to the message processor 110 during the data link period to the socket communication without changing the structure of the UDP / IP packet or an additional mechanism. A separate mechanism for data processing needs to be added when transmitting a message from the packet data processing unit 120 to the message processing unit 110 in the memory copy mode without using the VNI 210 or performing local socket communication. In addition, in case of local socket communication, it is necessary to generate a local socket separately from the LAN section socket, and since the data structure for processing the socket including the queue needs to be implemented and managed in a double, the complexity becomes high . On the other hand, when the VNI 210 is used, socket communication can be performed between a LAN section and a data link section with one socket through a simple procedure of IP address change and IP checksum reconfiguration. This makes it possible to simply maintain the socket data processing structure of the message processor 110 and maintain the data transfer time within a certain range as described above. Meanwhile, in the UAV, a packet transmitted to the message processing unit 110 based on the VNI 210 is divided into internal received data, and a packet transmitted from the VNI 210 to the data processing unit 120 is divided into internal transmission data Respectively. The internal data reception and transmission processing flow is shown in FIG. 8, the internal data reception processing method is shown in FIG. 9, and the internal data transmission processing method is shown in FIG. That is, FIG. 8 shows a data flow in the UAV and GCS according to transmission and reception of internal data, and FIGS. 9 and 10 are flowcharts for explaining a processing method, that is, a control method in accordance with transmission and reception of internal data Respectively. In FIG. 8, the same reference numerals are assigned to the same components in order to distinguish the data processing device of the UAV and the GCS data processing device.

8, the reception internal data of the UAV is input to the MAC frame processing unit 131 through the data link and is transmitted to the message processing unit 111 through the packet data processing unit 121 and the VNI 211 do. Here, the MAC frame processing unit 131 restores the data received through the data link into packets, divides the data into data types, and transmits the data to the packet data processing unit 121. The packet data processing unit 121 receives the MAC frame processing unit 130 ARP or DISCARD processing based on the IP address, and then forwards the packet data to the VNI 211. [ The message processor 111 receives the STANAG data using the UDP / IP socket communication method and transmits the socket data of the data link section received via the VNI 211 and the LAN data received through the network interface (NI) Handles the socket data of the interval as one socket. The transmission data from the GCS is input to the MAC frame processing unit 131 of the UAV through the LPI 222, the packet data processing unit 122, and the MAC frame processing unit 132 via the data link.

8, the transmission internal data of the UAV is inputted from the message processing unit 111 to the MAC frame processing unit 131 after being ARP-processed by the packet data processing unit 121 through the VNI 211 MAC frame, and then input to the GCS through the data link. In addition, the GCS receives the data input from the UAV through the data link, is transferred to the LPI 222 through the MAC frame processing unit 132 and the packet data processing unit 122, and then transmitted to the user interface.

As described above, the internal data reception and transmission of the UAV is performed through the message processing unit 111 and the VNI 211. That is, the internal data is not transmitted / received via the LPI 221, but is transferred from the message processing unit 111 via the VNI 211 or the VNI 211 to the message processing unit 111. On the other hand, although not shown, a modem and a radiator (antenna, etc.) may be provided between the UAV and the GCS. That is, the data of the MAC frame processing unit 130 of the UAV is transmitted to the GCS through the modem and the antenna, and the GCS can receive the data from the MAC frame processing unit 130 through the antenna and the modem. Also, although not shown, the UAV can transmit and receive Tm and Tc data from the UAV management module to the message processing unit 111, and the GCS can transmit and receive Tm and Tc data from the UAV to the NIC 312. That is, in the UAV, the message processing unit 111 is connected to the UAV management module, and the GCS is connected to the UAV controller.

3.1 Internal Data Reception Processing

9 is a flowchart for explaining a data processing method according to an embodiment of the present invention, and is a flowchart for explaining an internal data reception processing method. That is, FIG. 9 is a flowchart illustrating a method of processing data received from the MAC frame processing unit in the data processing unit of the UAV.

The destination IP address of the IP packet transmitted from the MAC frame processing unit 130 is compared with the NI IP address in step S301. If the IP address is identical to the destination IP address in step S301, the destination IP address is determined to be Tc for UAV control and transmitted to the message processing unit 110 via the VNI 210 (S302 to S304). In order to transmit the message to the message processing unit 110 via the VNI 210, a UDP / IP packet having a VNI IP address as a destination IP address should be input as a VNI. Since the data received from the MAC frame processing unit 130 is in the form of a UDP / IP packet, the destination IP address is changed to the VNI IP (S302), the IP checksum according to the IP header value change is recalculated (S303) (S304). The UDP header and payload are not modified, so the UDP cache is not recalculated. After receiving the message, the message processor 110 analyzes the IP address of the sender and stores the sender information in a variable form.

On the other hand, if the destination IP address and the NI address of the IP packet transmitted from the MAC frame processing unit 130 are not the same, the subnetwork of the destination IP address is checked to check whether or not the UAV is data (S305) ) And the NIC 310 to the LAN section (S306). If it is not confirmed, dis card processing is performed (S307).

3.2 Internal Data Transmission Processing

10 is a flowchart for explaining a data processing method according to an embodiment of the present invention, and is a flowchart for explaining an internal data transmission processing method. That is, FIG. 10 is a flowchart for explaining a data processing method of transmitting data inputted through the VNI to the MAC frame processing unit in the data processing unit of the UAV.

UAV flight, status information, etc. are sent to GCS as Tm of STANAG 4586 message format. The message processor 110 performs a corresponding function. The message processor 110 transmits a Tm in the same manner as a general socket transmission method to the GCS address information stored in the receiving process in order to transmit a message to the GCS. The packet data processing unit 120 receives data from the message processing unit 110 through the VNI 210 in step S401 and transmits a destination IP address to the packet data processing unit 110 in the same manner as the destination IP changing procedure in the internal data receiving process IP address (S402), and inputs it to the AMP queue through packet classification. The IP check sum is recalculated (S403) and forwarded to the MAC frame processing unit 130 (S405) through packet classification (S404). The input packet is received by the GCS over the data link interval in the UDP socket communication method.

Ⅲ. Performance Verification

1. Configure the test environment

1.1 Construction of test environment

The environment for performance verification is a 1: N data link in which one GCS manages and manages a large number of UAVs, using an omnidirectional antenna capable of beamforming without any additional orientation and efficiently using a narrow frequency band Tc and Tm based on STANAG 4586 standard can be transmitted and received by TDMA (Time Division Multiple Access) communication method. As shown in FIG. 11, a 1: N communication structure is difficult to use a plurality of actual UAVs. Therefore, one GCS data link communication device and two UAV data link communication devices are interlocked to form a 1: 2 communication environment Respectively. The data link for GCS and UAV communication is configured as shown in Table 1 to simulate a narrow frequency band. In the wireless environment, instead of using the antenna, RF cable of each data link communication equipment is connected by RF cable. For STANAG 4586 data processing, the GCS is connected to a notebook equipped with control software to periodically transmit and receive Tc and Tm data, and time slots are allocated so that data can be transmitted every 25 Hz by data type.

Parameter Value Channel Access TDMA Bandwidth (Hz) 4M Modulation 8PSK Code rate 2/3

[Table 2] shows the network information set so that the GCS, UAV # 1, and UAV # 2 can communicate with each other. It is configured to have different subnets based on Class-C, so that network communication based on IP address forwarding is required. As shown in FIG. 11, the traffic generator # 1 and the traffic generator # 2 are connected to the GCS, the UAV # 1, and the UAV # 2, respectively, so that data processing performance can be verified. In order to transmit / receive the data generated by the traffic generator between the traffic generators, the transmission / reception IP addresses of the traffic generator ports are set as shown in [Table 3]. With this configuration, the port # 1 of the traffic generators # 1 and # 2 is mutually transmittable and receivable, and the port # 2 of the traffic generators # 1 and # 2 is also set to be mutually transmittable and receivable.

Parameter IP Address SubnetMask GCS 192.168.0.100 255.255.255.0 Control GUI 192.168.0.60 255.255.255.0 UAV # 1 192.168.1.100 255.255.255.0 UAV # 2 192.168.2.100 255.255.255.0

Parameter IP Address Source Destination Traffic
Generator # 1 Port 1 192.168.0.20 192.168.1.20 Port 2 192.168.0.21 192.168.2.20 Traffic
Generator # 2 Port 1 192.168.1.20 192.168.0.20 Port 2 192.168.2.20 192.168.0.21

1.2 Test configuration setting As a method of performance verification, it is necessary to allocate time slots for Tc, Tm, and image data, and check whether Tc and Tm data processing is performed within a certain range of time Respectively. The image data is replaced with the data generated by the traffic generator so that the maximum transmission rate can be maintained for a certain period of time. Also, as a method for increasing the data processing load, by increasing the frame per second (FPS) by decreasing the frame size of the packet generated at the same transmission rate, the amount of packets processed per second in the data processing structure is increased.

The performance verification test is a method of measuring the average time by accumulating the round trip time (RTT) of data transmitted from the UAV GUI, generating data processing load on GCS, UAV # 1, UAV # 2 for 1 hour, Respectively. The RTT calculates the time difference after receiving the Tm responding from the UAV to the Tc transmitted from the UAV GUI. The data processing load is generated at different data processing points in the following order. First, it is set to generate data at an equal transmission rate in each traffic generator port, so that an equal load is generated in the data transmission / reception processing of the UAV # 1 and # 2. Second, the traffic generator # 1 connected to the GCS generates data at the minimum transmission rate to generate a data transmission load. The traffic generator # 1 and # 2 of the traffic generator # 2 connected to the UAVs # 1 and # 2 Transmission speed. The last test generates the maximum transmission rate at ports # 1 and # 2 of traffic generator # 1 connected to the GCS to generate a data reception load in contrast to the second test method and generates the maximum transmission rate of traffic generator # 2 connected to UAV # 1 and # 2 And data is generated at the minimum transmission speed on ports # 1 and # 2.

2. Verification Result

[Table 4] shows the transmission / reception direction of data generated through the traffic generator and the transmission rate allocated to the image data during the performance test using the uniform test method. As shown in FIG. 12, it can be seen that the variation range of the RTT is not large according to the transmission speed and the FPS variation, and the variation range of the processing time is maintained within a certain range.

Source Destination Data rate (Mbps) GCS UAV # 1 1.2096 GCS UAV # 2 1.2096 UAV # 1 GCS 1.2096 UAV # 2 GCS 1.2096

[Table 5] shows the transfer rates assigned to generate the data transmission load of the UAVs # 1 and # 2, which are the second tests. It assumes the data processing load that can occur when transmitting small images in UAV, and assumes 2.2Mbps image transmission per UAV. 13 is a graph showing the test results. As in the first test result, it can be seen that the range of RTT change according to the FPS change is not large and the range is maintained.

Source Destination Data rate (Mbps) GCS UAV # 1 0.1728 GCS UAV # 2 0.1728 UAV # 1 GCS 2.2464 UAV # 2 GCS 2.2464

[Table 6] shows the values assigned to allow the data reception load of the UAVs # 1 and # 2, which are the third tests, to occur. We assume the data processing load that can occur when transmitting large amounts of data for unmanned mission or control in GCS. 14 is a graph showing the test results and shows a pattern similar to that of the previous tests. As in the test 1 and 2, the width of the RTT change is kept constant even when the FPS value is changed can see.

Source Destination Data rate (Mbps) GCS UAV # 1 2.2464 GCS UAV # 2 2.2464 UAV # 1 GCS 0.1728 UAV # 2 GCS 0.1728

Even if the packet throughput of the data processing structure changes significantly in three test results that are set to cause different loads, the transmission time of Tc and Tm data and the response time therefor do not increase or decrease sharply and are maintained within a certain range Respectively. Also, it is confirmed that even if the data throughput increases due to the traffic increase in the data link interval, there is no error due to packet loss or redundancy.

As described above, the present invention proposes a data processing apparatus and method suitable for controlling a plurality of UAVs. Through the performance verification, it was confirmed that the data transmission time through the proposed data processing structure does not change drastically but remains within a certain range even if the processing load of packet data transmission / reception increases. This shows that, even if the traffic of the data link interval increases in a large number of UAVs, the transmission time of Tc and Tm can be guaranteed in a predictable range.

Although the technical idea of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for explanation purposes only and not for the purpose of limitation. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

110: Message processor 120: Packet data processor
130: MAC frame processing unit 210: VNI
220: LPI 230: NI
310: NIC

Claims (4)

A processing unit including a message processing unit, a packet data processing unit, and a MAC frame processing unit for processing external data transmitted and received by the UAV and internal data for controlling the UAV; a processing unit including a VNI, an LPI And a data processing apparatus including an interface unit including NI, the data processing method comprising:
The external data is transmitted / received through the LPI, the packet data processing unit and the MAC frame processing unit,
The internal data is transmitted / received through a message processing unit, a VNI, a packet data processing unit, and a MAC frame processing unit,
The internal data includes Tm data transmitted from the UAV to the GCS including the status, performance, and position information of the UAV, Tc data received from the GCS to the UAV for the UAV flight control,
The external data is obtained by processing packet data by ARP or DISK based on an IP address, converting the MAC frame data into MAC frame data, transmitting the data through the data link, restoring the MAC frame data received through the data link into packet data, And performs ARP or DISK processing on the received ARP,
The transmission of the external data includes:
Determining whether data transmitted from the UAV is effective data based on an IP address, performing an ARP request and response when the data is not valid data,
Comparing the destination of the data or the destination IP address with the NI address in case of valid data, or dis- card processing if the subnet check fails,
If the destination or the destination IP address and the NI address are not the same and the subnet check is successful, the packet data is divided and converted into MAC frame data,
The process of receiving the external data includes:
Checking the subnet of the destination IP address if the destination IP address and the NI address of the packet data received from the GCS are not the same,
Dis- card processing if the subnet check fails,
If the subnet check is successful, searching for the MAC address corresponding to the destination IP in the ARP table,
If the MAC address search is successful, an Ethernet header is generated and added to the packet data, and then transmitted through the LPI.
And performing an ARP request and response to the destination IP address according to the ARP transmission procedure when the MAC address search fails.
The method of claim 1, further comprising the step of determining the internal data if the destination IP address and the NI address of the packet data received from the GCS are the same.
The method of claim 2,
Comparing the destination IP address of the packet data with the NI address and changing the destination IP address to the VNI address if the destination IP address and the NI address are the same,
Recalculating the IP checksum according to the change of the IP header value,
Analyzing a destination IP address and storing destination information;
Checking whether the destination IP address and the NI address of the packet data are identical to each other or not by checking the subnet of the destination IP address;
Transmitting to the LAN section via the LPI if it is confirmed, and dis- carding if not confirmed.
4. The method of claim 3,
Generating internal data from the GCS address information stored in the internal data receiving step,
A process of re-calculating the IP checksum and distinguishing the packets after changing the destination IP address of the internal data to the NI address,
Converting the packet-classified internal data into MAC frame data, and transmitting the MAC frame data through the data link.

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