Patent Publication Number: US-2023154199-A1

Title: Driving control system and method of controlling the same using sensor fusion between vehicles

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from and the benefit of Korean Patent Application Nos. 10-2021-0158535 and 10-2021-0158536, filed on Nov. 17, 2021, which are hereby incorporated by reference for all purposes as if set forth herein. 
     BACKGROUND 
     Field 
     Exemplary embodiments of the present disclosure relate to a driving control system and a method of controlling the same using sensor fusion between vehicles, which recognize one or more adjacent vehicles by allowing the vehicles to share sensor data through communication and using the fused sensor data and control driving in response to the sensor data and the driving of the recognized vehicle. 
     Discussion of the Background 
     An autonomous vehicle refers to a vehicle that autonomously travels to a given destination by recognizing a surrounding environment and performing control to determine a traveling situation without a driver&#39;s intervention. 
     The vehicle performs autonomous driving while controlling a traveling direction by controlling a steering angle based on map information and acquired information. The vehicle acquires information on road or other vehicles positioned at the periphery by using a plurality of sensors, cameras, position information, and the like while traveling. The vehicle controls driving based on the acquired data. 
     Because the vehicle does not travel alone on the road, the vehicle needs to recognize a position of a peripheral vehicle and control driving in accordance with a change in position of the peripheral vehicle while preventing a collision between the vehicles. 
     In general, in case that the position recognition is performed precisely by a high-definition map (HDMap) and a GPS, it is possible to implement an autonomous driving system in the vehicle, without a sensor, by sharing, in real time, information on coordinates of objects by means of V2X (vehicle to anything). 
     However, there are problems in that a process of maintaining and repairing the HDMap cannot be performed in real time, and it is difficult to perform the position recognition because of a GPS coordinate error and a shadow zone. 
     Further, the vehicle needs to stably share information on peripheral objects in real time by using the V2X in various environments, but there is a limitation in stability, and information on vehicles manufactured in the past cannot be identified. Therefore, most of autonomous vehicles control autonomous driving by recognizing surrounding environments by using sensors. 
     In general, the autonomous driving system applied to the vehicle recognizes the surrounding environment by using an ultrasonic sensor, a camera, Radar, and Lidar. 
     The ultrasonic sensor, Radar, and Lidar respectively emit ultrasonic waves, electromagnetic waves, and light into the atmosphere and process reflected signals, thereby determining the presence or absence of peripheral obstacles. For this reason, there is a problem in that recognition performance is changed by a change in medium in a traveling situation. 
     The camera may provide not only information on obstacles but also information on roads such as lanes, like visual information of a person. However, it is not easy to recognize all various patterns indicated by a combination of the object and the background. In particular, there is a problem in that recognition performance deteriorates when the object and the background are similar to each other. 
     The autonomous vehicle is not yet perfectly operated, unlike a situation in which a person normally drives a vehicle. For this reason, an unexpected situation may occur partially. 
     Korean Patent No. 10-2205299 discloses a method of changing lanes by allowing vehicles to share data. The patent document proposes a technology for allowing the vehicle to move between the lanes by transmitting and receiving basic safety messages through communication between the vehicles and predicting a position of another vehicle in consideration of a communication delay time. 
     However, there is a limitation in stability of the shared data. Further, the technology has a limitation because the technology does not recognize the peripheral vehicle by adopting data in respect to the adjacent vehicle within a predetermined distance. 
     Accordingly, to overcome a limitation of recognition performance caused by a single sensor, there is a need for a solution related to an autonomous driving system that fuses information acquired by processing sensor signals, produces information with higher reliability, and uses the information to control a vehicle. 
     DOCUMENT OF RELATED ART 
     Patent Document 
     
         
         (Patent Document 1) Korean Patent No. 10-2205299 
       
    
     SUMMARY 
     Various embodiments are directed to providing a driving control system and a method of controlling the same using sensor fusion between vehicles, which recognize a peripheral environment by allowing the vehicles to share sensor data, fusing the sensor data, and matching the adjacent vehicle with the sensor data. 
     Various embodiments are directed to providing a driving control system and a method of controlling the same using sensor fusion between vehicles, which increase the number of sensors used to recognize a traveling environment by fusing sensor data, improve performance in recognizing a periphery, and control driving in accordance with a change in peripheral environment and a traveling state of another vehicle. 
     In an embodiment, a driving control system using sensor fusion between vehicles includes: a camera unit including a plurality of cameras and configured to capture an image of a periphery of a vehicle; a detection unit configured to measure a position of the vehicle and detect an object at the periphery of the vehicle; an image recognition unit configured to analyze the image captured by the camera unit, recognize a number plate of a second vehicle positioned at the periphery, and extract a vehicle identification number; a communication unit configured to include the vehicle identification number and sensor data acquired from the detection unit in an optional field of a basic safety message (BSM) and communicate with a plurality of vehicles positioned within a predetermined distance by a V2X (vehicle to anything) method; a data processing unit configured to match the plurality of vehicles and a plurality of basic safety messages based on at least one of the vehicle identification number and positions and operations of the plurality of vehicles; a coordinate conversion unit configured to extract sensor data from a basic safety message of the second vehicle on which matching is completely performed, the coordinate conversion unit being configured to convert the sensor data into a coordinate based on a host vehicle; and a control unit configured to control driving based on information on the periphery of the vehicle acquired by fusing data of the detection unit and the sensor data of the second vehicle based on a result of matching on the second vehicle. 
     The data processing unit may compare a vehicle identification number of the second vehicle and the vehicle identification number included in the plurality of basic safety messages and match the basic safety message coincident with the vehicle identification number with the second vehicle, and the data processing unit may analyze positions and operations of the plurality of vehicles based on information included in the plurality of basic safety messages in respect to a third vehicle having a number plate that is unrecognizable among the plurality of vehicles, compare the analysis result with data of the third vehicle detected by the detection unit, and match the third vehicle. 
     The data processing unit may compare at least one of position information, operation information, and object information of the third vehicle detected by the detection unit with data included in the plurality of basic safety messages and match the basic safety message coincident in an error range with the third vehicle. 
     The data processing unit may produce and register a new track in respect to the matched vehicle, change a matching candidate, which has succeeded matching for a predetermined period of time among the one or more matching candidates included in the matched data, to identified matching, convert the identified matching, which is not matched for the period of time among one or more identified matching, into a matching candidate, eliminate a track in respect to the matching candidate that is not matched for the period of time among one or more matching candidates, and manage a result of matching on the plurality of vehicles. 
     The coordinate conversion unit may acquire a coordinate in respect to a fourth vehicle detected by the second vehicle from the sensor data included in the basic safety message of the second vehicle and convert a coordinate of the fourth vehicle into a coordinate based on the host vehicle. 
     In case that a terrestrial magnetism sensor is included, the coordinate conversion unit may convert a coordinate value of the fourth vehicle detected by the second vehicle into a coordinate based on a traveling direction angle of the vehicle and a traveling direction angle of the second vehicle based on a north side (N-pole) detected by the terrestrial magnetism sensor. In case that no terrestrial magnetism sensor is included, the coordinate conversion unit may convert a coordinate of the fourth vehicle based on a difference between a traveling direction and a lane of a road on which the vehicle travels. 
     In an embodiment, a method of operating a driving control system using sensor fusion between vehicles according to another embodiment of the present disclosure includes: capturing, by a plurality of cameras, an image of a periphery of a vehicle and detecting a position of the vehicle and an object at the periphery of the vehicle; recognizing a number plate of a second vehicle from the image and extracting a vehicle identification number; including the vehicle identification number and sensor data in an optional field of a basic safety message (BSM) and performing communication with a plurality of vehicles positioned within a predetermined distance by a V2X (vehicle to anything) method; matching the plurality of vehicles and a plurality of basic safety messages based on at least one of the vehicle identification number and positions and operations of the plurality of vehicles; extracting sensor data from a basic safety message of the second vehicle on which matching is completely performed and converting a coordinate based on a host vehicle; acquiring information in respect to the periphery of the vehicle by fusing sensor data of the host vehicle and the sensor data of the second vehicle based on a result of matching on the second vehicle; and performing autonomous driving based on acquired information. 
     The matching of the plurality of vehicles and the plurality of basic safety messages may further include: comparing the vehicle identification number of the second vehicle having a recognized number plate with the vehicle identification number included in the plurality of basic safety messages; and matching a second basic safety message having a vehicle identification number coincident with the second vehicle with the second vehicle. 
     The matching of the plurality of vehicles and the plurality of basic safety messages may further include: detecting lane information and a position and operation of a third vehicle, which has a number plate that is not recognized, by using a plurality of sensors provided in a detection unit; analyzing at least one of lane information and positions and operations of the plurality of vehicles based on data included in the plurality of basic safety messages; setting up at least one matching candidate estimated as a basic safety message of the third vehicle; and comparing data of the third vehicle with the matching candidate and matching a third basic safety message coincident with data of the third vehicle in an error range with the third vehicle. 
     The method may further include: producing and registering a new track in respect to the third vehicle; changing a matching candidate, which has succeeded matching for a predetermined period of time among the one or more matching candidates included in the matched data, to identified matching; converting the identified matching, which is not matched for the period of time among one or more identified matching, into a matching candidate from the matched data; and eliminating a track in respect to the matching candidate that is not matched for the period of time among one or more matching candidates, in which a result of matching is managed based on accumulated data. 
     The converting of the coordinate may further include: acquiring a coordinate in respect to a fourth vehicle detected by the second vehicle from sensor data included in the basic safety message of the second vehicle; calculating a traveling direction angle of the vehicle and a traveling direction angle of the second vehicle based on a north side (N-pole) detected by a terrestrial magnetism sensor in case that the terrestrial magnetism sensor is included; compensating for a rotation by rotating the traveling direction angle of the vehicle by a difference of a rotation axis with respect to the fourth vehicle; compensating for a translation by using a distance between the vehicle and the second vehicle, a distance between the second vehicle and the fourth vehicle, and a rotation angle with respect to the fourth vehicle; and converting a coordinate value of the fourth vehicle detected by the second vehicle into a coordinate by using the rotation compensation and the translation compensation. 
     The converting of the coordinate may further include: acquiring a coordinate in respect to a fourth vehicle detected by the second vehicle from sensor data included in the basic safety message of the second vehicle; calculating a difference between a traveling direction and a lane of a road on which the vehicle travels in case that no terrestrial magnetism sensor is included; calculating a change in tangential gradient of the lane; calculating a rotation angle by using the difference between the lane and the traveling direction and the change in tangential gradient of the lane; and converting a coordinate value of the fourth vehicle detected by the second vehicle into a coordinate in response to the rotation angle. 
     The performing of the communication may include receiving the basic safety message including at least one of lanes, other vehicles, objects, traffic signals, and traffic information detected by the plurality of sensors and the vehicle identification number included in the optional field of the basic safety message from the plurality of vehicles. 
     In an embodiment, a driving control system using sensor fusion between vehicles includes: a camera unit including a plurality of cameras and configured to capture an image of a periphery of a vehicle; a detection unit configured to measure a position of the vehicle and detect an object at the periphery of the vehicle; an image recognition unit configured to analyze the image captured by the camera unit, recognize a number plate of a vehicle positioned at the periphery, and extract a vehicle identification number; a communication unit configured to include the vehicle identification number and sensor data acquired from the detection unit in an optional field of a basic safety message (BSM) and communicate with a plurality of vehicles positioned within a predetermined distance by a V2X (vehicle to anything) method; a data processing unit configured to match the plurality of vehicles and a plurality of basic safety messages based on at least one of the vehicle identification number and positions and operations of the plurality of vehicles; and a control unit configured to identify information on an erroneously detected vehicle or a non-detected vehicle through the basic safety message, the control unit being configured to restrict a traveling velocity and control driving of the vehicle based on the basic safety message in case that the erroneously detected vehicle or the non-recognized vehicle is present. 
     The control unit requests positions and detailed detection in respect to the erroneously detected vehicle and the non-recognized vehicle from the plurality of vehicles. 
     When information on a front vehicle, which is not detected by the detection unit, is identified from the basic safety message of the completely matched second vehicle, the control unit may prohibit acceleration and control driving based on the basic safety message of the second vehicle. When reliability in respect to data of the second vehicle is low, the control unit may decrease a maximum velocity and prepare braking by controlling a brake system. 
     When the front vehicle is detected by the detection unit, the control unit may identify whether a front vehicle is detected from the basic safety message of the completely matched second vehicle, and redetect the front vehicle by changing a recognition critical value of the detection unit in case that the front vehicle is not detected by the second vehicle. 
     The control unit may control the vehicle based on data of the detection unit when the front vehicle is detected after the redetection, and determine that the front vehicle is not present in case that the front vehicle is not detected. 
     In case that the front vehicle is not detected after the redetection of the front vehicle, the control unit may prohibit acceleration and control the driving based on the basic safety message. 
     In an embodiment, a method of controlling a driving control system using sensor fusion between vehicles according to still another embodiment of the present disclosure includes: capturing, by a camera, an image of a periphery of a vehicle and detecting a plurality of adjacent vehicles by using the image and a sensor of a detection unit; receiving basic safety messages (BSM) from the plurality of vehicles and matching the plurality of vehicles and a plurality of basic safety messages; identifying information on at least one of an erroneously detected vehicle and a non-recognized vehicle by the detection unit based on a basic safety message of a second vehicle on which matching is completely performed; and restricting a traveling velocity and controlling driving based on the basic safety message in case that the erroneously detected vehicle or the non-recognized vehicle is present. 
     The method may further include requesting positions and detailed detection in respect to the erroneously detected vehicle and the non-recognized vehicle from the plurality of vehicles. 
     When information on a front vehicle, which is not detected by the detection unit, is identified from the basic safety message of the second vehicle, acceleration may be prohibited, and the driving may be controlled based on the basic safety message of the second vehicle. 
     The method may further include decreasing a maximum velocity and preparing braking by controlling a brake system when reliability in respect to data of the second vehicle is low. 
     The method may further include: identifying whether a front vehicle is detected from the basic safety message of the second vehicle in respect to the front vehicle detected by the detection unit; and redetecting the front vehicle by changing a recognition critical value of the detection unit in case that the front vehicle is not detected by the second vehicle. 
     The method may further include controlling the vehicle based on data of the detection unit when the front vehicle is detected after the redetecting of the front vehicle; and determining that the front vehicle is not present in case that the front vehicle is not detected. 
     In case that the front vehicle is not detected after the redetecting of the front vehicle, acceleration may be prohibited, and the driving may be controlled based on the basic safety message. 
     According to the aspect, the driving control system and the method of controlling the same using sensor fusion between vehicles according to the present disclosure fuses and uses sensor data of another vehicle, which makes it possible to increase the detectable range and improve recognition performance related to the surrounding environment and object. 
     According to the aspect, the present disclosure may easily recognize a vehicle or object positioned at the periphery by converting the coordinate of the sensor data of the matched vehicle and fusing sensor data of the host vehicle, which makes it possible to improve recognition accuracy, prevent an accident caused by a collision, and improve stability of the vehicle. 
     According to the aspect, the present disclosure acquires and corrects information on an erroneously recognized vehicle by using sensor data of another vehicle even though the adjacent vehicle cannot be recognized or the vehicle, which is not present, is erroneously recognized, which makes it possible to accurately recognize the surrounding environment and improve the traveling stability. 
     According to the aspect of the present disclosure, the number of sensor data, which may be fused, increases in accordance with the number of adjacent vehicles, which makes it possible to increase the detectable range, enable stable autonomous driving, produce recognition data having high reliability, and improve the autonomous driving step. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram briefly illustrating a configuration of a driving control system using sensor fusion between vehicles according to an embodiment of the present disclosure. 
         FIG.  2    is a view for explaining data used for sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIGS.  3 A and  3 B  are exemplified views for explaining a vehicle recognition method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  4    is a flowchart illustrating a sensor fusion method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIGS.  5 A and  5 B  are views for explaining vehicle matching using position information of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  6    is a flowchart illustrating a vehicle matching method using position information of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  7    is a flowchart illustrating a method of managing matched data of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIGS.  8 A and  8 B  are exemplified views for explaining coordinate conversion of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  9    is an exemplified view illustrating an example related to vehicle matching of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  10    is a flowchart illustrating a driving control method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  11    is a view for explaining vehicle matching related to a non-recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  12    is a flowchart illustrating a non-recognized vehicle matching method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  13    is a view for explaining information correction related to an erroneously recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  14    is a flowchart illustrating a method of performing information correction on an erroneously recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  15    is a view for explaining vehicle matching using sensor data by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
         FIG.  16    is an exemplified view illustrating an example related to vehicle matching by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     Hereinafter, the present disclosure will be described with reference to the accompanying drawings. 
     Here, thicknesses of lines, sizes of constituent elements, or the like illustrated in the drawings, may be exaggerated for clarity and convenience of description. In addition, the terms used below are defined in consideration of the functions thereof in the present disclosure and may vary depending on the intention of a user or an operator or a usual practice. Therefore, such terms should be defined based on the entire contents of the present specification. 
       FIG.  1    is a block diagram briefly illustrating a configuration of a driving control system using sensor fusion between vehicles according to an embodiment of the present disclosure. 
     As illustrated in  FIG.  1   , the driving control system includes a camera unit  170 , a detection unit  160 , a data unit  180 , a communication unit  150 , an image recognition unit  120 , a data processing unit  130 , a coordinate conversion unit  140 , and a control unit  110  configured to control an overall operation. 
     The driving control system further includes a drive unit (not illustrated) configured to control a power source such as a motor (not illustrated), a battery management system (not illustrated) configured to manage a battery, a brake system (not illustrated), and a steering system (not illustrated). However, descriptions thereof will be omitted. 
     The detection unit  160  includes a plurality of sensors and detects an object adjacent to the periphery of the vehicle, for example, detects another vehicle, and the detection unit  160  detects a surrounding environment of the vehicle and road information. 
     The detection unit  160  includes a position sensor  161  configured to detect a position of the vehicle, and an obstacle sensor  162  configured to detect a peripheral object. 
     The position sensor  161  includes a GPS sensor and has a sensor capable of detecting a position of the current vehicle through communication with other devices. The position sensor  161  may include a sensor configured to detect a position by analyzing a signal transmitted or received by using a UWB method. 
     The obstacle sensor  162  detects an object positioned within a predetermined distance from the vehicle. The obstacle sensor  162  includes at least one of an infrared sensor, an ultrasonic sensor, a laser sensor, Radar, and Lidar. The obstacle sensor  162  may measure a distance from the detected object. 
     In addition, the detection unit  160  may include a vehicle velocity sensor, a temperature sensor, a pressure sensor, and the like and detect a traveling state of the vehicle and vehicle information. 
     The camera unit  170  includes a plurality of cameras  171  and  172  and capture images of the periphery of the vehicle. The camera unit  170  includes a first camera  171  installed at one side of a front portion of the vehicle or installed adjacent to a front glass and configured to capture an image of a front side in a traveling direction, and a second camera  172  installed at a rear side of the vehicle and configured to capture an image of the rear side. 
     In addition, the camera unit  170  may produce a surround view related to the periphery of the vehicle  10  by using the plurality of cameras. 
     The camera unit  170  applies the captured image to the control unit  110  and stores image data in the data unit  180 . The camera unit  170  may further include an image processing unit (not illustrated) that converts an image signal of the camera into image data in a predetermined format. 
     The data unit  180  stores control data for controlling the vehicle, data detected by the detection unit  160 , data transmitted or received by the communication unit  150 , and data related to the captured image. 
     The communication unit  150  includes a plurality of communication modules and performs CAN communication for transmitting or receiving data in the vehicle, near field communication such as Bluetooth, or wireless communication for connection with an external server or the like. 
     The communication unit  150  communicates with a road information server for providing an external database (DB) (not illustrated) or road information. The communication unit  150  receives information on the current position of the vehicle, information on road on which the vehicle travels, traffic information, traffic jam information, information on the periphery of the road, weather information, and the like. 
     The communication unit  150  may be connected to a portable terminal (not illustrated) of a driver through a near-field communication module. 
     The communication unit  150  communicates with another adjacent vehicle. 
     The communication unit  150  transmits and receives a basic safety message (BSM) by performing the communication with another vehicle by using a V2X (vehicle to anything) method. 
     The communication unit  150  includes and transmits sensor data to an optional field of the basic safety message (BSM), thereby allowing the vehicles to share the sensor data. 
     The image recognition unit  120  recognizes a number plate of another vehicle positioned at the periphery of the vehicle based on the image captured by the camera unit  170 . 
     The image recognition unit  120  may recognize a number plate of a vehicle positioned at the front side by using a front image and recognize a number plate of a vehicle positioned at the rear side by using a rear image. 
     In addition, the image recognition unit  120  analyzes a motion of another vehicle based on the captured image. The image recognition unit  120  analyzes operations related to a movement between lanes, whether acceleration or deceleration is performed, and the like based on the images of the vehicles positioned to front, rear, left, and right sides. 
     The data processing unit  130  distinguishes between the vehicles by extracting information included in the optional field of the basic safety message received through the communication unit, analyzing the extracted data, and matching the extracted data with the number plate recognized by the image recognition unit  120 . 
     The data processing unit  130  identifies the vehicle matched with the number plate. In case that the number plate cannot be recognized, the data processing unit  130  compares an operation of the vehicle analyzed based on the image with the data of the basic safety message and matches the vehicle. 
     The coordinate conversion unit  140  converts data of another vehicle included in the basic safety message into a coordinate based on a host vehicle. The coordinate conversion unit  140  may set up the coordinate conversion related to the matched vehicle in consideration of a relative position of the corresponding vehicle. 
     Because each of the vehicles records information on position or the like based on the host vehicle, the coordinate conversion unit  140  analyzes the data received from another vehicle and converts, based on the host vehicle, a coordinate set up based on the corresponding vehicle center. 
     During the autonomous driving, the control unit  110  sets up a route to a destination and performs control to perform autonomous driving based on road information acquired by the detection unit  160  and the camera unit  170 , the surrounding environment, and information on another adjacent vehicle. In addition, the control unit  110  controls a steering angle, controls an operation of the vehicle to accelerate or decelerate the vehicle, and controls a brake system (not illustrated) to stop the vehicle. 
     Because the autonomous driving method may be performed by using various known methods, a detailed description thereof will be omitted. 
     The control unit  110  recognizes an adjacent vehicle and tracks an operation of the vehicle based on a vehicle matching result through the basic safety message and the recognition of the number plate and based on a vehicle matching result through the basic safety message and the operation of the vehicle. 
     In addition, when the coordinate conversion unit  140  receives data of another vehicle recognized by the matched vehicle and converts sensor data of the vehicle into the coordinate, the control unit  110  fuses the coordinate and the data acquired from the detection unit  160  of the host vehicle by means of the basic safety message and controls the driving. 
     The control unit  110  analyzes the operation of another vehicle based on the sensor data of the received basic safety message and controls the driving in accordance with a change in operation of another vehicle. 
     The control unit  110  may use not only data of the detection unit  160  but also sensor data detected by another vehicle. Therefore, the control unit  110  may acquire a larger amount of information and also acquire information related to a blind spot, thereby easily tracking the operation of the peripheral vehicle and acquiring information on the periphery. 
     Even though the vehicle is not recognized from the image, the control unit  110  controls the driving by accelerating or decelerating the vehicle in response to a change in operation of the vehicle such as when the vehicle enters a traveling lane or when any one of front vehicles decelerates. 
     The control unit  110  outputs a notification related to a generated event, a change in operation of the recognized vehicle, changes during the traveling, and the like in the form of at least one combination of a notification message, alarm sound, a sound effect, a voice notification, and warning light through an output unit (not illustrated) while the vehicle travels. 
     Therefore, the driving control system of the vehicle  10  fuses, through the coordinate conversion, the sensor information of the host vehicle with the sensor data of the matched vehicle received through the basic safety message (BSM), thereby increasing the number of sensors used for the traveling environment recognition by using the sensor information of another vehicle. 
     The control unit  110  may be a controller typically called an electronic control unit (ECU), a micro-controller unit (MCU), and the like. The control unit  110  may include a processor and a memory coupled to the processor. The memory may store commands for allowing the processor to perform the operations of the control unit  110  according to the embodiment of the present disclosure and/or the steps of the present disclosure. 
     In addition, typically in the present field, some exemplary embodiments may be illustrated in the accompanying drawings in view of function blocks, units, and/or modules. Those skilled in the art may understand that the blocks, units, and/or modules are physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, processors, hard-wired circuits, memory elements, and wiring connections. In case that the block, unit, and/or module is implemented by a processor or other similar hardware, the block, unit, and/or module may be programmed or controlled by using software (e.g., codes) to perform various functions discussed in the present specification. In addition, the block, unit, and/or module may be implemented by exclusive hardware or implemented as a combination of exclusive hardware for performing a partial function and a processor (e.g., one or more programmed processors and relevant circuits) for performing other functions. In addition, the blocks, units, and/or modules in some exemplary embodiments may be physically divided into two or more interactive discrete blocks, units, and/or modules without departing from the concept of the present disclosure. In addition, the blocks, units, and/or modules in some exemplary embodiments may be physically coupled to more complicated blocks, units, and/or modules without departing from the concept of the present disclosure. 
       FIG.  2    is a view for explaining data used for sensor fusion between vehicles according to the embodiment of the present disclosure. 
     The driving control system exchanges a basic safety message (BSM) defined in a protocol (SAE J2735) with a device within a predetermined communication range, e.g., a range of 500 m for each particular period (ex: 100 ms) by using V2X. 
     As illustrated in  FIG.  2   , the driving control system may transmit and receive a basic safety message including an optional field as well as two data fields and determined data fields by using a V2X communication method. The driving control system may transmit and receive data including data related to recognized environment information and sensor data in addition to the optional field. 
     The basic safety message includes a first data field  181 , a second data field  182 , and an optional field  183 . 
     The driving control system transmits, to another vehicle, a basic safety message including the sensor data included in the optional field  183  and detects and uses the sensor data of the optional field included in the basic safety message of another vehicle. 
     The first data field  181  includes a basic vehicle state. The basic vehicle information includes information related to a message sequence number, temporary ID, time, position information (position latitude, longitude, elevation, and accuracy), a vehicle velocity, heading, steering wheel angle, acceleration information (vehicle accelerations and yaw rate), a brake status, a vehicle length, a vehicle width, and the like. 
     The second data field  182  includes a vehicle events object, a vehicle path history object, a vehicle path prediction object, and a vehicle relative positioning RTCM 1002 data object. 
     The optional field  183  includes sensor data and a vehicle identification number (license plate). The sensor data may include lanes, information on other vehicles, signal information (traffic signs), traffic signals, and the like. 
     Because no data are assigned to the optional field  183 , the optional field  183  may include data related to detected sensor data, recognized environment information, a number plate, and the like. 
     The driving control system shares the sensor data by using the optional field  183  of the basic safety message and acquires information on the periphery by fusing the sensor data with the data detected by the driving control system. 
     For example, assuming that two vehicles A and B exist at the front side and travel at the same velocity and acceleration, the driving control system, it is difficult to distinguish between vehicle A and vehicle B only by using a GPS signal because there is an error of several meters in GPS position information. 
     The driving control system may distinguish between the two vehicles, which are not easily distinguished, by fusing the sensor data included in two basic safety messages transmitted from the vehicles with the sensor data measured by the detection unit  160  of the host vehicle and matching the vehicles with the sensor data. 
     The driving control system may match the vehicles by recognizing the number plate of the vehicle. Further, the driving control system may match the vehicles by distinguishing between operations of the vehicles based on the sensor data of the vehicles. 
       FIGS.  3 A and  3 B  are exemplified views for explaining a vehicle recognition method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  3 A , the driving control system recognizes a number plate of another vehicle by using the plurality of cameras of the camera unit  170 , particularly, the first camera  171  configured to capture the front image, and the first camera  172  configured to capture the rear image. The driving control system recognizes a number plate of a rear vehicle based on the rear image. 
     The image recognition unit  120  of the driving control system recognizes the vehicles from the images, separates the images of the vehicles, and then recognizes the number plates of the vehicles. 
     It is mandatory to mark a vehicle registration number (vehicle identification number) on the number plate of the vehicle, which is provided in the form of a rectangular metal plate, in order to manage the vehicle. The vehicle identification number marked on the number plate is the only number assigned to a single vehicle. Therefore, the driving control system performs the vehicle matching by using the vehicle identification number. 
     The image recognition unit  120  extracts the vehicle identification number by recognizing the number plate. The data processing unit compares the extracted vehicle identification number with the vehicle identification number included in the basic safety message and matches the basic safety message with the vehicle having the recognized number plate. 
     The driving control system includes the sensor data and the vehicle identification number in the optional field  183  of the basic safety message (BSM). Therefore, the driving control system may not only identify the vehicle from which the basic safety message is received, but also distinguish between the vehicles by matching the vehicles with the vehicle identification numbers recognized from the images and match the actual vehicles with the basic safety message. 
     The driving control system acquires images from the first camera  171  at the front side and the second camera  172  at the rear side and recognizes the vehicles and the number plates by using the image recognition unit  120 . The driving control system uses pre-stored learning data and extracts the vehicle identification number by means of a technology for recognizing letters or numbers from images based on deep learning. 
     In some instances, the driving control system may be connected to an external server through the communication unit  150  and extract the vehicle identification number from the image based on deep learning. 
     The driving control system uses an object recognition network and detects a vehicle and a bounding box that surrounds transverse letters. 
     Because the number plate is mounted at a center of a vehicle bumper, the driving control system extracts a bounding box of a letter class included in a vehicle bounding box with an added margin as a candidate group, changes a size of a region of the letter bounding box to a predetermined size, and recognizes letters by inputting an image of the letter bounding box to an optical character recognition (OCR) network. 
     The recognized letter string is as illustrated in  FIG.  3 B . 
     The driving control system determines the consistency indicating whether the recognized letter string is coincident with a number plate format. Because the standard of the number plate may vary for each country, the driving control system determines one letter string or two letter strings depending on the standard. 
     For example, in case that a plurality of letter strings is recognized, the driving control system determines the consistency indicating whether the letters, among GENESIS, GV80, 4WD, and 129CHA2912, conform to the number plate format. 
     In addition, in case that a plurality of letter strings is recognized in one vehicle, the driving control system determines the consistency in respect to a result of combining the two letter strings. 
     For example, the driving control system may combine GENESIS, GV80, 4WD, and 129CHA2912 into GENESISGV80, GV804WD, and the like and determine the consistency. 
     The driving control system recognizes 129CHA2912, which conforms to the number plate format, as the number plate through the combination and the consistency analysis related to the recognized letter strings. 
       FIG.  4    is a flowchart illustrating a sensor fusion method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  4   , the driving control system receives a basic safety message (BSM) from another vehicle through the communication unit  150  (S 310 ). The basic safety message may be transmitted to or received from other vehicles within a predetermined distance at regular intervals by the V2X method. 
     During the communication, the driving control system transmits the sensor data including at least one of lanes, other vehicles, objects, traffic signals, and traffic information detected by the plurality of sensors and the vehicle identification number included in the optional field of the basic safety message. The driving control system receives the basic safety message including the sensor data from the plurality of vehicles. 
     The driving control system analyzes the images acquired by the plurality of cameras  171  and  172  of the camera unit  170 , and the image recognition unit  120  distinguishes between the vehicles in the images and recognizes the number plate in the image region determined as the vehicle (S 320 ). 
     The driving control system acquires the vehicle identification number by analyzing the image of the recognized number plate based on deep learning (S 340 ). The driving control system compares the vehicle identification number, which is extracted from the optional field of the basic safety message (BSM) by the data processing unit  130 , with the vehicle identification number recognized from the number plate and determines whether the two vehicle identification numbers are coincident with each other (S 340 ). 
     When the vehicle identification number extracted from the optional field of the basic safety message is coincident with the vehicle identification number recognized from the image, the data processing unit  130  matches the sensor data with the corresponding vehicle identification number (S 350 ). 
     Meanwhile, when the vehicle identification number extracted from the optional field of the basic safety message is not coincident with the vehicle identification number recognized from the image or when there is no coincident vehicle identification number, the data processing unit  130  sorts the vehicle into a vehicle positioned in a non-recognized region in which it is difficult to recognize the number plate from the image (S 370 ). The data processing unit  130  may perform the vehicle matching based on the vehicle operation or vehicle position to be described below in respect to the vehicle in the non-recognized region. 
     The data processing unit  130  stores the data related to the matched vehicle in the data unit  180  and tracks the operation of the corresponding vehicle (S 360 ). 
     The coordinate conversion unit  140  converts the sensor data included in the basic safety message of the matched vehicle into a coordinate based on the host vehicle. 
     The control unit  110  acquires information on the periphery of the vehicle by fusing the data of the detection unit  160  and the sensor data of the matched vehicle with the converted coordinate and controls the autonomous driving based on the information. 
     For example, in case that a vehicle positioned at the front side is matched, a traveling velocity may be controlled in response to a change in velocity of the front vehicle to prevent a collision. Further, when a front right vehicle moves between the lanes, the driving may be controlled in response to the movement of the front right vehicle. 
       FIGS.  5 A and  5 B  are views for explaining vehicle matching using position information of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     In case that the vehicle  10  is matched with the basic safety message by recognizing the number plate by using the image of the camera, the accuracy of the vehicle matching is improved, but a distance between the vehicles needs to be short to the extent that the letter string may be identified. 
     In addition, in case that the number plate of the vehicle  10  is recognized based on the image captured by the camera, number plates of a front vehicle, a rear vehicle, a left front vehicle, a left rear vehicle, a right front vehicle, and a right rear vehicle may be recognized. However, in case that the vehicle is positioned at the left or right side or an angle of view of the camera is partially included, the number plates of the plurality of vehicles are hardly recognized from the images, and the vehicles cannot be matched by using the images. 
     Therefore, the driving control system matches the vehicle based on the position or operation of the vehicle in case that the data processing unit  130  cannot recognize the number plate from the image. 
     The driving control system may erroneously match the vehicles when performing the matching only by using an absolute coordinate, a velocity, and direction information at a particular point in time because of an error of the GPS and a likelihood that the message and the vehicle detected by the sensor correspond to each other in a multi-to-multi corresponding manner. Therefore, the driving control system tracks the matched vehicle, identifies whether information related to a plurality of samples has consistency, and then finally performs the vehicle matching. The driving control system may improve the accuracy by reidentifying whether the vehicle matching is normally completed by tracking the vehicle. 
     As illustrated in  FIG.  5 A , in case that the vehicle positioned adjacent to a side lane, the driving control system may receive a GPS value and a sensor value of the vehicle. 
     The data processing unit  130  configures an actually measured vehicle candidate region by mapping the vehicle value measured by the sensor within a GPS error range of the host vehicle, produces a candidate region related to the vehicle, which has transmitted the basic safety message, by applying the GPS error range to the received basic safety message (BSM), and sets up a matching candidate by obtaining an intersection with the candidate region related to the actually measured vehicle. 
     The data processing unit  130  determines a matching failure in case that there are multiple information intersections between the sensor value and the GPS value and the vehicles cannot be distinguished even when the information on the GPS and the sensor with the identified matching is eliminated. 
     The data processing unit  130  matches a GPS signal of the host vehicle with respect to a first vehicle V 1  and a sensor value received from the first vehicle V 1  and matches a GPS signal of the host vehicle with respect to a second vehicle V 2  and a sensor value of the second vehicle V 2 . 
     However, the data processing unit  130  determines a matching failure because the candidate regions related to the first and second vehicles overlap. 
     In addition, the data processing unit  130  determines a matching failure in respect to the corresponding vehicle in case that there is no data matched with the GPS value of the host vehicle with respect to a third vehicle e. 
     As illustrated in  FIG.  5 B , in case that the driving control system may identify a longitudinal position of a vehicle, i.e., in case that a distance difference is larger than a GPS error or a velocity difference may be identified, the driving control system matches the vehicles through the position intersection between the GPS value and the sensor value, produces a track, and then performs the tracking. 
     The data processing unit  130  matches the GPS signal of the host vehicle with respect to the first vehicle V 1  and the sensor value received from the first vehicle V 1  and matches the GPS signal of the host vehicle with respect to the second vehicle V 2  and the sensor value of the second vehicle V 2 . Because the regions of the first and second vehicles do not overlap, the driving control system matches the vehicle, produces the track, and performs the tracking. 
     The driving control system finally performs the vehicle matching based on a tracking result. 
       FIG.  6    is a flowchart illustrating a vehicle matching method using position information of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  6   , the driving control system manages the matched vehicle by tracking an operation of the matched vehicle. 
     The data processing unit  130  matches the actually measured vehicle and the basic safety message by matching the autonomously measured position related to the vehicle and the position information included in the basic safety message (S 410 ). 
     The data processing unit  130  identifies whether the matching is already identified based on an ID (temporary ID) included in the basic safety message (S 420 ). In case that the matching is identified matching, the data processing unit  130  performs the vehicle matching (S 460 ). 
     In case that the matching is not identified matching, the data processing unit  130  determines whether the number of expected candidates to be matched is one (S 430 ). 
     In case that the number of expected candidates is one, the data processing unit  130  matches the corresponding candidate and the vehicle (S 460 ). 
     Meanwhile, in case that the number of expected candidates is two or more, the data processing unit  130  determines whether the matching may be performed by using velocity information of the vehicle (S 440 ). The data processing unit  130  calculates a velocity of the vehicle, compares the velocity with the velocity of the vehicle included in the basic safety message, and matches the vehicle (S 460 ). 
     In case that the matching cannot be performed by the velocity, the data processing unit  130  determines whether the matching may be performed by lane information (S 450 ). In case that the matching may be performed by the lane information, the data processing unit  130  performs the vehicle matching based on the lane and a traveling direction of the vehicle (S 460 ). 
     In case that the host vehicle and a candidate vehicle are positioned on edge lanes or a traveling lane may be recognized based on a guard rail or the like, the data processing unit  130  may match the vehicle by extracting the sensor data from the optional field of the basic safety message (BSM) and determining whether the sensor data is identical to the sensor information. 
     In case that the matching may be performed by the velocity, the data processing unit  130  matches the vehicle based on the vehicle velocity of the basic safety message (S 460 ). 
     Meanwhile, the data processing unit  130  determines a matching failure in case that the matching is not identified, the number of expected candidates is two or more, and the matching cannot be performed by the velocity and lane information. 
       FIG.  7    is a flowchart illustrating a method of managing matched data of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  7   , in case of recognize the number plate from the image and matching the vehicle based on the information on position or operation of the vehicle, the driving control system tracks the operation of the corresponding vehicle and identifies whether the vehicle matching is normally performed. 
     The data processing unit  130  fuses a previous matching result and a new matching result based on the ID of the basic safety message (S 470 ). 
     The data processing unit  130  registers a new track related to a matching candidate (S 490 ) in respect to new matching (S 480 ). The driving control system tracks and records the operation of the vehicle with the matched information. 
     The data processing unit  130  determines whether there is a track having succeeded in preset long-term matching among the matching candidates in respect to the previous matching (S 500 ). In case that there is the track having succeeded in long-term matching, the corresponding matching candidate is changed to identified matching (S 510 ). 
     The data processing unit  130  determines whether there is a candidate that has not been subjected to long-term matching in respect to the identified matching (S 520 ). In respect to the candidate that has not been subjected to the long-term matching among the matching candidates, the corresponding identified matching is changed to the matching candidate (S 530 ). 
     In addition, the data processing unit  130  determines whether there is a candidate that has not been subjected to the long-term matching among the matching candidates (S 540 ), and the candidate, which has not been subjected to the long-term matching, eliminates the matching candidate track (S 550 ). 
     The data processing unit  130  matches the vehicle based on the position or operation of the vehicle and registers and manages the track in respect to the matched vehicle. Therefore, the data processing unit  130  may change the candidate to the identified matching based on the matching result for a predetermined period of time or change the identified matching to the candidate. Further, the data processing unit  130  may manage information on the vehicle matching in accordance with a vehicle tracking record by eliminating the track from the candidate that is not matched for a period of time. 
       FIGS.  8 A and  8 B  are exemplified views for explaining coordinate conversion of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     The driving control system fuses sensor information by transmitting or receiving the sensor data included in the optional field of the basic safety message (BSM) of the V2X. The driving control system converts the sensor data of the matched vehicle into a host vehicle coordinate system by moving parallelly based on relative coordinate information measured by a host vehicle sensor and rotating and changing by using a rotation angle calculated based on a terrestrial magnetism sensor, a lane, and a traveling direction. 
     As illustrated in  FIG.  8 A , when a basic safety message (BSM) and sensor data of a counterpart vehicle are completely matched, the coordinate conversion unit  140  identifies a relative coordinate between the vehicles based on the sensor data. 
     The coordinate conversion unit  140  fuses sensor data measured by the vehicles by adding information on the terrestrial magnetism sensor or lane reference direction and transmits the information on the terrestrial magnetism sensor or lane reference traveling angle, which may indicate a direction difference between the vehicles by using the optional field of the basic safety message (BSM). 
     The driving control system of the vehicle  10  matches the vehicle and detects a target vehicle by using sensor data of another vehicle. 
     For example, the first vehicle  11  travels in an eleventh direction D 11  that defines a first angle θ e  with respect to a north side N, and the second vehicle  12  travels in a twenty-first direction D 21  that defines a second angle θ v  with respect to the north side N. 
     The first vehicle  11  may match and identify the second vehicle  12  and identify the third vehicle  13  based on data included in the basic safety message of the second vehicle  12 . 
     The second vehicle  12  is detected as a coordinate (R t , θ t ) with respect to the third vehicle  13 , and the first vehicle  11  converts a coordinate of the third vehicle  13  into a coordinate with respect to the host vehicle through the basic safety message (BSM) of the second vehicle  12 . 
     The first vehicle  11  compensates for the rotation and translation of the coordinate system during the coordinate conversion. 
     The first vehicle  11  shares traveling direction angles θ e  and θ v  of the vehicle based on the north side N and an N-pole by using the terrestrial magnetism sensor and compensates for the rotation by rotating and converting a rotation axis difference by (θ e −θ v ). In addition, the first vehicle  11  compensates for the translation by using a distance R s  from the second vehicle measured by the host vehicle sensor and a rotation angle θ s  with respect to the third vehicle. 
     The first vehicle  11  calculates a coordinate (R f , θ f ) by converting a position of the third vehicle  13 , which is a target vehicle detected by another vehicle, into the host vehicle coordinate system. 
     The coordinate conversion of the third vehicle  13  by the first vehicle  11  may be calculated based on Equation 1 below. 
     
       
         
           
             
               
                 
                   
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     The coordinate is converted by using a traveling direction angle between the first vehicle  11  and the second vehicle  12 , a straight distance R s  between the first vehicle  11  and the second vehicle  12 , a straight distance R t  between the second vehicle  12  and the third vehicle  13 , and rotation angles θ s  and θ t  with respect to the third vehicle. 
     As illustrated in  FIG.  8 B , in case that there is no terrestrial magnetism sensor or an error is large, the driving control system of the vehicle  10  converts the coordinate by using the lane or the like. 
     A fourth vehicle  14  calculates a direction angle difference by sharing a traveling angle based on the lane by using the optional field of the basic safety message (BSM). 
     When the fourth vehicle  14  travels in a forty-first direction D 41  that is the traveling direction, the fourth vehicle  14  calculates a direction angle θ 4  with respect to the forty-first direction D 41 , which is the traveling direction, based on a tangential direction D 42  with respect to the lane. 
     When a fifth vehicle  15  travels in a fifty-first direction D 51  that is the traveling direction, the fifth vehicle  15  calculates a direction angle θ 5  with respect to the fifty-first direction D 51 , which is the traveling direction, based on tangential directions D 52  and D 53  with respect to the lane. 
     Assuming that an equation of the lane of the fourth vehicle  14  is f(o) and an equation of the lane of the fifth vehicle  15 , which is the identified matched vehicle, is g(o), a change in tangential gradient of the lane is tan −1 (f′(x))−tan −1 (f′0). 
     A rotation angle for rotating and converting an obstacle position into the host vehicle coordinate system is calculated based on a change in tangential gradient of the lane, tan −1 (f′0) and tan −1 (g′0), the difference between the traveling direction and the lane obtained by the vehicle. 
       Rotation angle=tan −1 ( f ′( x ))−tan −1 ( f ′(0))−tan −1 ( g ′(0))  [Equation 2]
 
     Therefore, the vehicle  10  may obtain a position of an obstacle in the host vehicle coordinate system, which is detected in the identified matched vehicle, by performing the translation by R s  and θ s  that is host vehicle sensor information. 
       FIG.  9    is an exemplified view illustrating another example related to vehicle matching of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     The driving control system transmits and receives the basic safety message (BSM) to and from the vehicle within a predetermined distance for a predetermined period, detects the number plate from the image captured by the camera unit  170  by using the image recognition unit  120 , compares the number plate with the vehicle identification number included in the basic safety message, and matches the vehicle. In case that the recognition of the number plate may be performed, the driving control system matches the vehicle based on the number plate. In case that the recognition of the number plate cannot be performed, the driving control system matches the vehicle based on the position or operation of the vehicle. 
     As illustrated in  FIG.  9   , when the matching and coordinate conversion in respect to another vehicle are completed, the driving control system fuses and uses sensor data of another vehicle. 
     The control unit  110  acquires information on the surrounding environment by fusing data obtained by the detection unit  160  and the sensor data of another vehicle and controls the autonomous driving by detecting approach of another vehicle. 
     The first vehicle  21  matches the vehicle by recognizing the number plate in respect to the third vehicle  23  and matches the vehicle based on the position in respect to the second vehicle  22 . 
     The first vehicle  21  receives the basic safety message of the second vehicle  22  and the third vehicle  23  and uses the sensor data, thereby increasing the number of available sensors. 
     The first vehicle  21  may also acquire information on a vehicle disposed forward of the third vehicle  23  by using the sensor data of the matched vehicle. 
     Therefore, the driving control system may use sensors larger in number than the provided sensors, produce data having high reliability, and precisely control driving in accordance with a motion (operation) of an adjacent vehicle. 
       FIG.  10    is a flowchart illustrating a driving control method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  10   , the driving control system of the vehicle recognizes a peripheral vehicle by using an image captured by the camera (S 570 ). 
     The driving control system transmits and receives the basic safety message (BSM) to and from the vehicle within a predetermined distance for a predetermined period (S 580 ). 
     The driving control system detects the number plate from the image captured by the camera unit  170  by using the image recognition unit  120  and recognizes the vehicle identification number from the number plate. 
     In case that the recognition of the number plate may be performed, the driving control system matches the vehicle based on the number plate (S 600 ). In case that the recognition of the number plate cannot be performed, the driving control system matches the vehicle based on the position or operation of the vehicle (S 610 ). 
     As described above, the driving control system may match the vehicle identification number with the vehicle identification number included in the basic safety message and match the vehicle by performing the tracking based on the position or operation of the vehicle. 
     When the vehicle matching is completed, the driving control system extracts sensor data included in the optional field of the basic safety message of the matched vehicle (S 620 ). 
     Because the driving control system knows information on the relative position between the vehicles after the matching is completed, the driving control system may improve obstacle recognition performance by transmitting the data acquired from the sensors. 
     Because the position information of the sensor data is determined based on the position of the vehicle, the driving control system converts data of another vehicle into the coordinate based on the host vehicle. 
     Because the driving control system requires rotation information for the coordinate conversion, the driving control system converts the coordinate by calculating conversion angle information based on the terrestrial magnetism sensor or lane. 
     In case that the terrestrial magnetism sensor is provided (S 630 ), the coordinate is converted based on a measured value of the terrestrial magnetism sensor as described above with reference to  FIG.  8 A  (S 640 ). As illustrated in  FIG.  8 B , in case that no terrestrial magnetism sensor is provided, the coordinate is converted based on the lane and traveling direction (S 650 ). 
     The driving control system couples the converted coordinate of another vehicle to a coordinate value of its own sensor (S 660 ) and controls driving in response to the recognized operation of the vehicle, data, and the like (S 670 ). 
       FIG.  11    is a view for explaining vehicle matching related to a non-recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  11   , the driving control system may determine whether the first vehicle  21  and the fourth vehicle  24  are present based on the sensor data of the basic safety message (BSM) received from the second vehicle  22  in a situation in which the fourth vehicle  24  positioned forward of the first vehicle  21  cannot be recognized. 
     During the process in which the first vehicle  21  travels, the first vehicle  21  recognizes the vehicle positioned at the front side based on the front image and detects the vehicle positioned in detection regions A 13  and A 14  by using the plurality of sensors. 
     However, even though the first vehicle  21  is positioned forward of the fourth vehicle  24 , the fourth vehicle  24  sometimes cannot be recognized. 
     In case that the first vehicle  21  cannot recognize the fourth vehicle from the image, the fourth vehicle may be recognized by using the plurality of sensors. However, the fourth vehicle  24  cannot be recognized in case that the fourth vehicle  24  is positioned at a position deviating from the detection region of the sensor. 
     For example, abnormality may occur on the camera of the first vehicle  21 , foreign substances may be attached to a front glass, a shape of the fourth vehicle cannot be normally recognized, and the fourth vehicle  24  cannot be detected from the image because of at least one of weather situations. In addition, the first vehicle  21  cannot clearly identify a front state in a weather situation such as heavy snow, fog, or the like, and the vehicle sometimes cannot be recognized. 
     In case that the fourth vehicle  24  is positioned at a position out of the detection regions A 13  and A 14  in the situation in which the fourth vehicle  24  cannot be recognized from the image as described above, the first vehicle  21  may determine that no vehicle is present at the front side without recognizing the fourth vehicle  24 . 
     In this situation, in case that the first vehicle  21  accelerates after determining that no other vehicle is present at the front side, there may occur an accident in which the first vehicle  21  and the fourth vehicle  24  collide with each other. Because the fourth vehicle is positioned in the detection region, a braking distance may increase in an acceleration situation, and a collision accident may occur even though the first vehicle  21  detects the fourth vehicle while accelerating and performs braking. 
     In this case, even though the first vehicle  21  determines that no vehicle is present at the front side without recognizing the fourth vehicle  24 , the first vehicle  21  may identify the vehicle detected and matched by the second vehicle  22  through the sensor data included in the basic safety message of the second vehicle  22  before the first vehicle  21  accelerates. 
     The driving control system determines whether information on a non-recognized vehicle exists in the data received from the second vehicle  22 , and the driving control system controls driving based on data on the corresponding vehicle in case that the information on the non-recognized vehicle exists. 
     In addition, the driving control system determines reliability related to the data of the second vehicle  22  and controls driving in accordance with the reliability. The driving control system determines that the fourth vehicle  24  is present when the reliability related to the data of the second vehicle  22  is high. 
     In case that the reliability is high, the driving control system estimates a position of the fourth vehicle  24  based on the sensor data and controls driving in response to the position of the fourth vehicle  24 . 
     The driving control system restricts acceleration so that the acceleration is not performed even though the reliability of the data of the second vehicle  22  is high, and the driving control system controls the vehicle based on the sensor data of the received basic safety message. 
     In case that the reliability related to the data of the second vehicle  22  is low, the driving control system restricts a maximum velocity. In addition, the driving control system prepares braking to decelerate the vehicle immediately after the vehicle is detected by the sensor in order to prepare for a case in which the fourth vehicle  24  is actually positioned forward of the vehicle. For example, the driving control system may prepare braking by charging a brake with pressure. 
     The driving control system may request the second vehicle  22  to precisely detect the position of the vehicle in respect to the fourth vehicle  24  that is the non-recognized vehicle. In addition, the driving control system may request the data related to the fourth vehicle  24  from another adjacent vehicle. 
     In case that the driving control system receives the data related to the non-recognized fourth vehicle  24  through the plurality of basic safety messages received from the plurality of vehicles, the driving control system compares the data of the second vehicle, determines the position of the fourth vehicle  24 , and recognizes the vehicle. 
     The driving control system estimates the position of the fourth vehicle  24  based on the sensor data and controls driving in response to the position of the fourth vehicle  24 . 
       FIG.  12    is a flowchart illustrating a non-recognized vehicle matching method of the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  12   , the driving control system recognizes the vehicle based on the image captured by the camera and detects a peripheral vehicle based on the plurality of sensors (S 700 ). The driving control system performs the vehicle matching based on the number plate of the vehicle recognized from the image. 
     The control unit  110  of the driving control system receives data from an adjacent vehicle by transmitting and receiving the basic safety message (BSM) to and from the adjacent vehicle. 
     The first vehicle  21  determines whether information on a non-recognized vehicle exists based on the basic safety message (BSM) of the second vehicle  22  (S 720 ). 
     In case that the second vehicle  22  detects the fourth vehicle  24 , which is a preceding vehicle traveling on the same lane as the first vehicle  21 , in the situation in which the first vehicle  21  cannot detect a front vehicle, the first vehicle  21  may identify information on the fourth vehicle through the sensor data of the second vehicle  22 . 
     The control unit  110  controls the vehicle, which corresponds to the fourth vehicle  24  that is a non-recognized vehicle, based on data reliability of the second vehicle. The reliability refers to data set up as a level or numerical value based on whether the vehicle, which has transmitted the data, is the matched vehicle, the stability according to the transmission or reception of data, the accuracy of the vehicle data, and the distance between the vehicles. 
     The control unit  110  determines a level related to reliability of the second vehicle  22 . When the reliability is lower than a predetermined value, the control unit  110  restricts a velocity by reducing a maximum velocity (S 740 ) and prepares braking to immediately decelerates the vehicle (S 750 ). In a situation in which it is impossible to determine whether the fourth vehicle  24 , which is a non-recognized vehicle, is actually positioned at the front side, the control unit restricts the velocity of the vehicle and prepares braking to brake the vehicle immediately after the vehicle is detected by the sensor in consideration of a likelihood of a collision. 
     Meanwhile, in case that the reliability related to the data of the second vehicle  22  is as high as a predetermined value or more, the control unit  110  determines that the fourth vehicle  24  is positioned at the front side and prohibits acceleration in consideration of a likelihood of a collision in an acceleration situation (S 760 ). 
     The control unit  110  controls the vehicle based on the received basic safety message (BSM) (S 770 ). 
     The control unit  110  requests detailed information related to the fourth vehicle  24 , which is a non-recognized vehicle, from another adjacent vehicle (S 780 ), estimates the position of the fourth vehicle  24  based on the received data, and controls the vehicle (S 790 ). The control unit  110  determines that the fourth vehicle  24  is positioned at the estimated position even though the fourth vehicle  24  is not actually detected, and the control unit  110  controls driving based on the determination result. 
     When the front vehicle is detected by the image or sensor while the front vehicle travels, the driving control system performs the vehicle matching based on any one of the recognition of the number plate, the vehicle position, and the vehicle operation. When the driving control system determines the detected vehicle as the fourth vehicle  24 , the driving control system sorts the fourth vehicle into matched vehicles and tracks the operation of the fourth vehicle  24 . In addition, the driving control system receives the basic safety message of the fourth vehicle and controls the first vehicle. 
       FIG.  13    is a view for explaining information correction related to an erroneously recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  13   , the driving control system detects a fifth vehicle  25  positioned forward of the first vehicle  21 . When the driving control system determines that the fifth vehicle  25  is present in a detection region A 16  by the sensor in a state in which the fifth vehicle  25  cannot be recognized from the image, the driving control system determines that the fifth vehicle is present at the corresponding position. 
     To identify the fifth vehicle  25 , the driving control system determines whether the fifth vehicle  25  is present based on the sensor data of the basic safety message (BSM) received from the second vehicle  22 . 
     Whether the second vehicle  22  detects the fifth vehicle  25  is determined based on the sensor data included in the basic safety message of the second vehicle  22 . In case that the second vehicle  22  cannot detect the fifth vehicle, the fifth vehicle  25  detected by the sensor may be determined as a ghost vehicle, i.e., a vehicle that is not actually present. 
     In case that there is no vehicle that detects the fifth vehicle based on the basic safety message or in case that the vehicle is not included even in the data track candidate of the matched vehicle, the driving control system determines the fifth vehicle  25  as a ghost vehicle. 
     Before the driving control system determines the fifth vehicle as the ghost vehicle, the driving control system resets a vehicle recognition critical value so that the vehicle is detected again in a wider range. The driving control system may change detection sensitivity or detection range of the sensor and change recognition setting according to the image. 
     After the reset, the driving control system redetermines whether the fifth vehicle  25  is detected. In case that the fifth vehicle is detected, the driving control system determines that the fifth vehicle is actually present, and the driving control system controls the vehicle based on the sensor data. 
     Meanwhile, when the fifth vehicle is not detected after the driving control system resets the critical value, the driving control system determines the fifth vehicle  25  as a ghost vehicle. The driving control system prohibits acceleration in consideration of a case in which the fifth vehicle is present, and the driving control system controls the vehicle based on the received basic safety message. 
     The driving control system requests detailed information related to the fifth vehicle based on a basic safety message received from an adjacent vehicle, reidentifies whether the fifth vehicle is detected by another vehicle, identifies whether the vehicle is included in the track candidate of another vehicle, and determines the fifth vehicle as a ghost vehicle. Meanwhile, when the fifth vehicle is detected by the plurality of vehicles, the driving control system may match the fifth vehicle. 
     When a new vehicle is detected by the sensor or image even after the fifth vehicle is determined as a ghost vehicle, the driving control system identifies whether the new vehicle is the fifth vehicle by means of vehicle matching, and the driving control system controls the driving of the vehicle based on the identification result. 
       FIG.  14    is a flowchart illustrating a method of performing information correction on an erroneously recognized vehicle by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  14   , the driving control system detects the fifth vehicle  25  positioned at the front side by using the sensor (S 800 ). 
     The control unit  110  receives the basic safety message (BSM) from the second vehicle  22  (S 810 ) and determines whether the fifth vehicle  25  is present based on the sensor data included in the basic safety message (S 820 ). 
     The control unit  110  may determine whether the second vehicle  22  detects the fifth vehicle  25  or whether the fifth vehicle is matched based on the sensor data included in the basic safety message of the second vehicle  22 . The driving control system determines positions of objects detected based on its own reference by converting the sensor data of the second vehicle into the coordinate. 
     In case that the data of the fifth vehicle  25  are not present in the sensor data of the second vehicle  22 , i.e., in case that the second vehicle cannot detect the fifth vehicle, the control unit  110  resets the critical value related to the recognition of the vehicle and redetermines the vehicle in response to a case in which the signal is erroneously detected (S 830 ). 
     The control unit  110  resets the vehicle recognition critical value and then determines whether the fifth vehicle  25  is detected by the detection unit  160  (S 840 ). When the fifth vehicle is detected, the control unit performs the vehicle matching by means of the data processing unit  130  and controls the driving of the vehicle based on the sensor data (S 850 ). 
     Meanwhile, when the fifth vehicle is not detected after the control unit resets the critical value, the control unit determines the fifth vehicle  25  as a ghost vehicle. However, the control unit  110  prohibits acceleration in consideration of a case in which the fifth vehicle is present (S 860 ), and the control unit controls the vehicle based on the received basic safety message (S 870 ). 
     The control unit  110  requests detailed information on the fifth vehicle based on a basic safety message received from an adjacent vehicle (S 880 ). 
     In case that the fifth vehicle is detected and determined as a ghost vehicle, the control unit  110  identifies a detailed position through the basic safety message, reidentifies whether the fifth vehicle is a ghost vehicle, and then control the vehicle (S 890 ). 
       FIG.  15    is a view for explaining vehicle matching using sensor data by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     The autonomous driving controls the driving by recognizing an adjacent vehicle or object based on received data and data detected by the vehicle instead of the driver. Therefore, the stability and reliability need to support the autonomous driving. During the autonomous driving, the vehicle may set up steps related to the autonomous driving and set up a restriction to operations performed in respective steps. The steps of the autonomous driving may be divided into 5 steps. Steps 0 to 2 are limited to operations that assist the driver&#39;s driving, and Steps 4 or more drive the vehicle without the driver&#39;s intervention and are states in which the driver&#39;s intervention is performed as necessary. Step 5 corresponds to perfect autonomous driving. 
     As described above, there may occur a problem in that a vehicle, which is not present, is detected or a vehicle, which is present, cannot be detected. Therefore, because of the limitation in recognition performance, the autonomous vehicle performs the step of assisting the driver&#39;s driving control. 
     However, the driving control system according to the present disclosure may perform the vehicle matching by recognizing the number plate from the image and using the basic safety message and identify a plurality of erroneously detected or non-recognized vehicles by receiving sensor data of another vehicle, thereby correcting an error. 
     The driving control system may recognize the non-recognized object by receiving sensor data of another vehicle through a basic safety message even in respect to an object positioned at a blind spot. 
     Therefore, the driving control system may use the data detected by not only the sensor of the host vehicle but also a sensor of another vehicle, such that a size of a detectable region is greatly increased. Further, the driving control system may redetermine the erroneously detected or non-recognized object, thereby more accurately recognizing an object and controlling driving. 
     As illustrated in  FIG.  15   , during the driving, the driving control system receives a basic safety message BSM 1  from the second vehicle  22 , a basic safety message BSM 2  from a seventh vehicle  27 , and a basic safety message BSM 3  from an eighth vehicle  28 . The driving control system performs the vehicle matching by receiving the data of the vehicle through the received basic safety message (BSM). 
     When the vehicle matching is completely performed on the adjacent vehicle, the driving control system may share the data through the basic safety message, identify the traveling states of the vehicle, and control the driving in response to the operations of the vehicles. 
     Even though the front vehicle is not recognized, the driving control system may receive the basic safety messages of the second vehicle  22  and the seventh vehicle  27 , which are peripheral vehicles, convert the sensor data into the coordinate, and identify the coordinate. Therefore, the driving control system may reidentify whether the corresponding vehicle is present and estimate the position of the vehicle, thereby solving a problem caused by non-recognition or erroneous recognition. 
     Therefore, the driving control system may perform the autonomous driving in higher steps as the recognition performance is improved. 
       FIG.  16    is an exemplified view illustrating an example related to vehicle matching by the driving control system using sensor fusion between vehicles according to the embodiment of the present disclosure. 
     As illustrated in  FIG.  16   , the driving control system determines recognition performance and changes an autonomous driving step. 
     The image recognition unit  120  recognizes a lane based on the image captured by the camera of the camera unit  170 . In addition, the image recognition unit  120  extracts the vehicle identification number from the number plate by recognizing the front vehicle from the image. 
     The data processing unit  130  performs the vehicle matching based on the vehicle identification number through the sensor data included in the basic safety message received through the communication unit  150 . The data processing unit  130  may match the vehicle based on the operation or position of the object vehicle. 
     To determine the recognition performance, the control unit  110  determines whether the lane is recognized by the image recognition unit  120  (S 900 ) and determines whether the front vehicle is recognized and whether the matching is completely performed on the front vehicle (S 910 ). 
     The control unit  110  determines whether the matching is completely performed on the vehicle positioned on the left or right lane and determines whether the front vehicle is recognized by another vehicle through the basic safety message received from the matched vehicle (S 920 ). 
     The control unit  110  determines whether the vehicle, which is not matched, is present among the vehicles positioned on the left and right lanes (S 930 ). The control unit  110  stores the data related to the matched vehicle in the data unit  180  and manages the matched vehicle. 
     In addition, the control unit  110  determines whether the driver keeps eyes forward during the driving and determines whether the driver holds the steering wheel (S 940 ). 
     The control unit  110  may capture an image of the interior of the vehicle by using the camera, and the image recognition unit  120  may detect whether the driver keeps eyes forward from the image and whether the driver holds the steering wheel. 
     The control unit  110  increases the autonomous driving step by 1 step when a plurality of items for determining the recognition performance is all satisfied (S 950 ). 
     Meanwhile, in case that even any one of the plurality of items is not satisfied, the control unit  110  identifies the current autonomous driving step and decreases the autonomous driving step by 1 step (S 980 ) when the current autonomous driving step is Step 3 of the autonomous driving (S 970 ). The control unit  110  may maintain the autonomous driving step in case that the autonomous driving step is Step 2. 
     When the autonomous driving step is changed by increasing or decreasing, the control unit  110  predicts and outputs a notification in accordance with a change in autonomous driving step (S 960 ). 
     Even after the autonomous driving step is increased, the control unit  110  periodically redetermines the recognition performance and adjusts the autonomous driving step. 
     While the present disclosure has been described with reference to the embodiment illustrated in the drawings, the embodiment is described just for illustration, and those skilled in the art to the present technology pertains will understand that various modifications of the embodiment and any other embodiment equivalent thereto are available. Accordingly, the true technical protection scope of the present disclosure should be determined by the appended claims. 
     Although exemplary embodiments of the disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as defined in the accompanying claims. Thus, the true technical scope of the disclosure should be defined by the following claims.