Patent Publication Number: US-2021182575-A1

Title: Device and method for generating travel trajectory data in intersection, and vehicle-mounted device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is based on Japanese Patent Application No. 2018-163073 filed Aug. 31, 2018, and Japanese Patent Application No. 2019-147339 filed Aug. 9, 2019, the descriptions of which are incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     This disclosure relates to a device and a method for generating travel trajectory data in an intersection, and a vehicle-mounted device. 
     Related Art 
     There is a technique for accurately measuring a shape and a location of a road using a special-purpose vehicle and generating travel trajectory data for autonomous driving. In principle, this technique needs expensive sensors and considerable amounts of human work, and can only generate travel trajectory data related to a limited extent, such as a freeway, a car-only road and the like. Travel trajectory data related to an open road can not be generated and thus travel trajectory data in or within an intersection can not be generated. In view of the foregoing, it is desired to have a technique for generating travel trajectory data in an intersection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a functional block diagram of the overall configuration of one embodiment; 
         FIG. 2  is a functional block diagram of a controller of a map data generation device; 
         FIG. 3  is a functional block diagram of an image recognizer; 
         FIG. 4  is a flowchart of the overall process; 
         FIG. 5  is an illustration of line markings in an intersection; 
         FIG. 6  is a flowchart of a process of generating travel trajectory data using line markings; 
         FIG. 7  is an illustration of travel trajectory data; 
         FIG. 8  is an illustration of areas of specific colors in an intersection; 
         FIG. 9  is a flowchart of a process of generating travel trajectory data using areas of specific colors; 
         FIG. 10  is an illustration of travel trajectory data; 
         FIG. 11  is an illustration of striped areas in an intersection; 
         FIG. 12  is a flowchart of a process of generating travel trajectory data using striped areas; 
         FIG. 13  is an illustration of travel trajectory data; 
         FIG. 14  is an illustration of a diamond-shaped marking in an intersection; 
         FIG. 15  is a flowchart of a process of generating travel trajectory data using a diamond-shaped marking; 
         FIG. 16  is an illustration of travel trajectory data; 
         FIG. 17  is an illustration of a roundabout; 
         FIG. 18  is a flowchart of a process of generating travel trajectory data in a roundabout; and 
         FIG. 19  is an illustration of travel trajectory data. 
     
    
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS 
     For example, JP-A-2017-97088 discloses a technique for estimating a new road using a GPS trajectory that indicates a Global Positioning System (GPS) location of a vehicle as an absolute trajectory, and estimating a connection between the estimated new road and an existing road, and thereby updating a map data. In addition, for example, JP-A-2010-26875 discloses a technique for connecting an entering lane that enters an intersection and an existing lane that exits from the intersection with a circular arc (e.g., a quadratic Bezier curve) to generate travel trajectory data in the intersection. 
     There is an issue with the technique disclosed in JP-A-2017-97088 that large variations in GPS location may reduce the accuracy of the travel trajectory data. In addition, there is an issue with the technique disclosed in JP-A-2010-26875 that since there are a variety of travel trajectories of vehicles depending on intersection shapes, the travel trajectory data is likely to deviate from the actual travel trajectory and thus impractical. 
     In view of the foregoing, it is desired to have a technique for appropriately generating travel trajectory data that is data enabling specification of a travel trajectory in an intersection for autonomous driving. 
     According to one aspect of the present disclosure, a road marking recognizer is configured to recognize a road marking in an intersection using captured image data of the intersection. A travel trajectory data generator is configured to, in response to a result of recognition by the road marking recognizer, generate travel trajectory data that is data enabling specification of a travel trajectory in the intersection for autonomous driving. 
     A road marking in an intersection is recognized using captured image data of the intersection. Travel trajectory data that is data enabling specification of a travel trajectory in the intersection for autonomous driving is generated in response to a result of recognition. Where a road marking actually exists on a road in an intersection, travel trajectory data is generated in response to the actually existing road marking, which enables appropriate generation of the travel trajectory data in the intersection for autonomous driving. 
     Hereinafter, one embodiment will be described with reference to the accompanying drawings. In the map data generation system  1 , as illustrated in  FIG. 1 , a vehicle-mounted device  2  mounted to each vehicle and a map data generation device  3  located on the network side are data communicatively connected via the communication network. There is a many-to-one relationship between the vehicle-mounted devices  2  and the map data generator  3 . The map data generation device  3  is able to data-communicate with a plurality of the vehicle-mounted devices  2 . 
     The vehicle-mounted device  2  includes a controller  4 , a data communication unit  5 , a positioning unit  6 , an image data input unit  7 , an autonomous driving controller  8 , and a storage device  9 . These functional blocks are data communicatively connected via an internal bus  10 . The controller  4  is configured as a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and input/output interface (I/O). The controller  4  is configured to perform processes corresponding to the computer programs by executing the computer programs stored in the non-transitory tangible storage medium, thereby controlling the overall operations of vehicle-mounted device  2 . 
     The data communication unit  5  controls data communication with the map data generation device  3 . The positioning unit  6  includes a Global Positioning System (GPS) receiver, an acceleration sensor, a geomagnetic sensor, and others, and determines a current location of the vehicle-mounted device  2  and outputs positioning data indicating the current location and a time of day of positioning to the controller  4 . The vehicle-mounted camera  11  is installed separately from the vehicle-mounted device  2  and captures images of, for example, forward scenes of the vehicle, and outputs captured image data as vehicle image data to the vehicle-mounted device  2 . Upon receipt of the vehicle image data from the vehicle-mounted camera  11 , the image data input unit  7  outputs the received vehicle image data to the controller  4 . The vehicle-mounted camera  11  is not limited to the camera for capturing images of the forward scenes of the vehicle. The vehicle-mounted camera  11  may be a camera for capturing images of rear scenes or side scenes of the vehicle. The camera for capturing images of rear scenes or side scenes of the vehicle is attached to the vehicle body with a larger depression angle than the camera that captures images of forward scenes of the vehicle, which can provide advantages of easy acquisition of clear image data. Alternatively, a plurality of the cameras that capture images of forward scenes, rear scenes, and side scenes of the vehicle may be employed. 
     The autonomous driving controller  8  is configured to, upon receipt of a control signal from the controller  4 , control the operations of the autonomous driving electronic control unit (ECU)  12  and control autonomous driving of the vehicle. 
     The storage device  9  includes a probe data storage  13  storing probe data and a map data storage  14  storing map data. The map data storage  14  includes an initial map data storage  15  storing initial map data described later. The initial map data includes travel trajectory data that indicates travel trajectories when the vehicle actually travels using the autonomous driving function. The autonomous driving controller  8  controls the autonomous driving of the vehicle using the travel trajectory data included in the initial map data. The autonomous driving controller  8  estimates a position and an orientation of the vehicle in an intersection using, for example, image data captured by the vehicle-mounted camera  11  and causes the vehicle to travel along the travel trajectory indicated by the travel trajectory data. The position and the orientation of the vehicle in the intersection are determined based on installation information, such as sizes and degrees of tilt of a plurality of landmarks included in the image data captured by the vehicle-mounted camera  11  using, for example, an optical navigation technique. With such a configuration, the position and the orientation of the vehicle can be estimated more accurately as compared with when the GPS positioning result or a result of a dead reckoning process is used as it is. The landmarks will be described later. 
     The controller  4  associates the positioning data received from the positioning unit  6  with the vehicle image data received from the image data input unit  7 , and regularly stores the probe data including the associated positioning data and the vehicle image data in the probe data storage  13 . Every predetermined time interval or every time the traveled distance of the vehicle reaches a predetermined distance, the controller  4  reads the probe data from the probe data storage  13  and transmits the read probe data from the data communication unit  5  to the map data generation device  3 . In addition, upon the data communication unit  5  receiving the initial map data delivered from device  3 , the controller  4  stores the received initial map data in the initial map data storage  15 . 
     The map data generation device  3  includes a controller  16 , a data communication unit  17 , and a storage device  18 . These functional blocks are data communicatively connected via an internal bus  19 . The controller  16  is configured as a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and input/output interface (I/O). The controller  16  is configured to perform processes corresponding to the computer programs by executing the computer programs stored in the non-transitory tangible storage medium, thereby controlling the overall operations of the map data generation device  3 . The computer programs to be executed by the controller  16  includes a travel trajectory data generation program. 
     The data communication unit  17  controls data communication with the vehicle-mounted device  2 . The storage device  18  includes a probe data storage  20  storing probe data and a map data storage  21  storing map data. The map data storage  14  includes a road information data storage  33  storing road information data described later, an intersection-to-intersection travel trajectory data storage  34  storing intersection-to-intersection travel trajectory data, and an in-intersection travel trajectory data storage  36  storing travel trajectory data in intersections, a landmark data storage  37  storing landmark data, and an initial map data storage  38  storing initial map data. 
     Upon the data communication unit  17  receiving the probe data transmitted from the vehicle-mounted device  2 , the controller  16  stores the received probe data in the probe data storage  20 . Upon the controller  16  generating the initial map data described later, the controller  16  causes the data communication unit  17  to deliver the generated initial map data to the vehicle-mounted device  2 . That is, since the vehicle-mounted device  2  and the map data generation device  3  are in a many-to-one relationship, the controller  16  stores plural pieces of probe data transmitted from the plurality of vehicle-mounted devices  2  in the probe data storage  20 , and causes the data communication unit  17  to deliver the initial map data to the plurality of vehicle-mounted devices  2 . 
     The controller  16  has a function of generating travel trajectory data. As illustrated in  FIG. 2 , the controller  16  includes, as functional blocks, an image recognizer  22 , a road information data generator  23 , an intersection-to-intersection travel trajectory data generator  24 , and in-intersection travel trajectory data generator  25 , a landmark data generator  26 , and an initial map data generator  27 . 
     The image recognizer  22  receives inputs of navigation map data stored in the navigation map data storage  28 , basis map data stored in the basis map data storage  29 , aerial photo data stored in the aerial photo data storage  30 , satellite photo data stored in the satellite photo data storage  31 , vehicle image data stored in vehicle image data storage  32 , performs image-recognition process on these input data, and outputs a recognition result to the road information data generator  23 . The navigation map is map data used in a navigation system installed in the vehicle. The basis map data is map data issued by, for example, the Geospatial Information Authority of Japan. The aerial photo data is photographic data of the ground captured by a camera mounted to an aircraft. The satellite photo data is photographic data of the ground captured by cameras mounted to the satellites. The vehicle image data is image data of road surfaces captured by the vehicle-mounted cameras  11  described above, and included in the probe data stored in the probe data storage  20 . 
     The road information data generator  23 , upon receipt of a recognition result from the image recognizer  22 , generates road information data using the received recognition result. The road information data is data including a road type, such as a national road or a prefectural road, a traffic type, such as one-way traffic or two-way traffic, road-related information, such as a road width. Upon generation of the road information data, the road information data generator  23  stores the generated road information data in the road information data storage  33 . 
     The intersection-to-intersection travel trajectory data generator  24  receives inputs of navigation map data and road information data, and uses these input data to generate intersection-to-intersection travel trajectory data. The travel trajectory data between intersections is data indicating intersection-to-intersection travel trajectories that the vehicle travels during autonomous driving. Upon generation of the intersection-to-intersection travel trajectory data, the intersection-to-intersection travel trajectory data generator  24  stores the generated travel trajectory data between intersections in the intersection-to-intersection travel trajectory data storage  34 . 
     The in-intersection travel trajectory data generator  25  receives inputs of the existing collected data stored in the existing collected data storage  35  and the road information data, and generates the travel trajectory data in the intersection using the input data. The travel trajectory data in the intersection is data indicating a travel trajectory in the intersection that the vehicle travels during autonomous driving. Upon generating the travel trajectory data in the intersection, the in-intersection travel trajectory data generator  25  stores the generated the travel trajectory data in the intersection in the in-intersection travel trajectory data storage  36 . The travel trajectory data generated by the travel trajectory data generator  25  may be any one of data indicating a virtual lane in an intersection, data used when the vehicle actually passes through an intersection during autonomous driving, and data used as terrestrial object data. That is, the travel trajectory data generated by the travel trajectory data generator  25  may be data used directly by the vehicle during autonomous driving, or may be data used indirectly by the vehicle during autonomous driving. The travel trajectory data for making a right turn corresponds to, for example, data indicating an area or a center line in an intersection, in or along which the vehicle has to travel during autonomous driving, or terrestrial objects that define the area or the center line. The travel trajectory data for making a left turn corresponds to, for example, data indicating an area or a center line in an intersection, in or along which the vehicle has to travel during autonomous driving, or terrestrial objects that define the area or the center line. 
     The landmark generator  26  receives inputs of existing collected data and road information data, and generates landmark data using the input data. The landmark data is data indicating installation locations, types, sizes and the like of signs and signboards on roads. The landmarks may further include traffic lights, stop lines, channelizing strips, edges of lanes, and others. Upon generating landmark data, the landmark generator  26  stores the generated landmark data in the landmark data storage  37 . 
     The initial map data generator  27  receives inputs of the travel trajectory data between intersections stored in the intersection-to-intersection travel trajectory data storage  34 , the travel trajectory data in intersections stored in the in-intersection travel trajectory data storage  36 , and the landmark data stored in the landmark data storage  37  and generates initial map data using these input data. The initial map data is data integrating the travel trajectory data between intersections and the travel trajectory data in intersections. Upon generating the initial map data, the initial map data generator  27  stores the generated initial map data in the initial map data storage  38 . 
     As illustrated in  FIG. 3 , the image recognizer  22  includes a pre-detection processor  39 , a detection processor  40 , and a recognition processor  41  as a configuration for generating travel trajectory data in an intersection. 
     The pre-detection processor  39  includes a brightness adjuster  39   a,  a roadside tree masker  39   b,  and a vehicle detector  39   c.  The brightness adjuster  39   a  adjusts the brightness of the aerial photo data, the satellite photo data, and the vehicle image data to a level suitable for image recognition. The roadside tree masker  39   b  masks roadside tree parts included in the aerial photo data, the satellite photo data, and the vehicle image data. The vehicle detector  39   c  detects vehicles included in the aerial photo data, the satellite photo data and the vehicle image data. 
     The detection processor  40  includes a white-line intensity calculator  40   a,  a noise masker  40   b,  a white-line center detector  40   c,  and a white-line information generator  40   d.  The white-line intensity calculator  40   a  determines the intensity of each white line painted on the road included in the aerial photo data, the satellite photo data, and the vehicle image data. The noise masker  40   b  masks noise included in the aerial photo data, the satellite photo data, and the vehicle image data. The white-line center detector  40   c  detects the center of each white line painted on the road included in the aerial photo data, the satellite photo data, and the vehicle image data. The white-line information generator  40   d  generates information, such as the intensity and the center of each white line. 
     The recognition processor  41  includes a channelizing strip recognizer  42  (corresponding to a road marking recognizer), an arrow recognizer  43 , and a stop-line recognizer  44 . The channelizing strip recognizer  42  is a functional block that uses the aerial photo data, the satellite photo data, and the vehicle image data as image data of an intersection to recognize road markings in the intersection. The channelizing strip recognizer  42  includes a line marking recognizer  42   a,  an area recognizer  42   b,  a striped area recognizer  42   c,  and a diamond-shape recognizer  42   d.  The line marking recognizer  42   a  recognizes line markings painted on a road in an intersection included in the aerial photo data, the satellite photo data, and the vehicle image data. The area recognizer  42   b  recognizes areas of specific colors (e.g., blue, red and the like that are different from the asphalt color) painted on a road in an intersection included in the aerial photo data, satellite photo data, and the vehicle image data. 
     The striped area recognizer  42   c  recognizes striped areas painted on a road in an intersection included in the aerial photo data, the satellite photo data, and the vehicle image data. The diamond-shaped recognizer  42   d  recognizes a diamond-shaped marking painted on a road in an intersection included in the aerial photo data, the satellite photo data, and the vehicle image data. The channelizing strips are these line markings, areas of specific colors, striped areas, and diamond-shaped markings in an intersection, which are markings for guiding safe and smooth driving of vehicles in an intersection. 
     The arrow recognizer  43  recognizes arrows painted on a road in an intersection, included in the aerial photo data, the satellite photo data, and the vehicle image data. The stop line recognizer  44  recognizes stop lines painted on a road in an intersection, included in the aerial photo data, the satellite photo data, and the vehicle image data. 
     Operations of the above-described configuration will now be described with reference to  FIGS. 4-19 . 
     The controller  16  sequentially performs a pre-detection process, a detection process, and a recognition process in the image recognizer  22 , and performs a travel trajectory data generation process in the in-intersection travel trajectory data generator  25 . The controller  16  performs, as the pre-detection process, brightness adjustment (at S 1 ), roadside tree masking (at S 2 ), and vehicle detection (at S 3 ) on the aerial photo data, the satellite photo data, and the vehicle image data. Upon completing the pre-detection process, the controller  16  performs, as the detection process, white-line intensity calculation (at S 4 ), noise masking (at S 5 ), white-line center detection (at S 6 ), and white-line information generation (at S 7 ) on the aerial photo data, the satellite photo data, and the vehicle image data that were processed in the pre-detection process. 
     Upon completion of the detection process, the controller  16  performs, as a recognition process, channelizing strip recognition (at S 8  to S 11  corresponding to a channelizing strip recognition procedure) on the aerial photo data, the satellite photo data, and the vehicle image data that were processed in the detection process. That is, the controller  16  performs line marking recognition (at S 8 ) to recognize line markings painted on a road in an intersection, and performs area recognition (at S 9 ) to recognize areas of specific colors painted on a road in an intersection. The controller  16  performs striped area recognition (at S 10 ) to recognize striped areas painted on a road in an intersection, and performs diamond-shape recognition (at S 11 ) to recognize diamond-shaped markings painted on a road in an intersection. Subsequently to the channelizing strip recognition, the controller  16  performs arrow recognition (at S 12 ) to recognize arrows painted on a road in an intersection, and performs stop-line recognition (at S 13 ) to recognize stop lines painted on a road in an intersection. Then, upon completion of the recognition process, the controller  16  generates travel trajectory data in the intersection in response to a recognition result (at S 13  corresponding to a trajectory data generation procedure). 
     The process of generating travel trajectory data will now be described with reference to  FIGS. 5  to  FIG. 19 . In the following, it is assumed that the vehicle is traveling in an area to which a road traffic act that regulates left-hand traffic is applied. In such an area that a road traffic act that regulates the left-hand traffic is applied, the vehicle has to cross oncoming lanes to make a right turn. 
     (1) Process of Generating Travel Trajectory Data by Recognizing Lane Markings on a Road in an Intersection 
       FIG. 5  illustrates an example of an intersection where the north-south direction road is a two-way road having two lanes for each direction and the east-west direction road is a two-way road having three lanes for each direction. The east-west direction road has a right turn only lane for each direction. The term “intersection” as used herein includes not only an area where the north-south direction road and the east-west direction road intersect, but also areas having arrow painted. Therefore, the intersection means a broader area (indicated by a dashed-two dotted line A in  FIG. 5 ) than the area of the two roads intersect. 
     As illustrated in  FIG. 6 , the controller  16  performs the recognition process. Upon recognizing line markings on a road in an intersection (at S 21 ), the controller  16  generates travel trajectory data in the intersection in response to a recognition result (at S 22 ). Upon generating the travel trajectory data in the intersection, the controller  16  complements connections at both ends of the generated travel trajectory data such that the travel trajectory data is smoothly connected to the travel trajectory data between intersections at both the entrance-to-intersection end and exit-from-intersection end of the travel trajectory data, thereby correcting the shape and location of the travel trajectory data (at S 23 ). 
     That is, where line markings a 1  and a 2  are painted on the road in the intersection for the right turn only lane entering the intersection from the east-direction, the controller  16  recognizes the painted line markings a 1  and a 2 . Similarly, where markings a 3  and a 4  are painted on the road in the intersection for the right turn only lane that the controller  16  entering the intersection from the west-direction, the controller  16  recognizes line markings a 3  and a 4 . 
     Where striped areas e 1  and e 2  are painted on the road in the intersection, the controller  16  recognizes the painted striped areas e 1  and e 2  and thus recognizes the no-entry area for the vehicle. Where a diamond-shaped marking f 1  is painted on the road in the intersection, the controller  16  recognizes the diamond-shaped marking and thus recognizes an approach direction for the vehicle. Where right-turn arrows c 1  and c 2  are painted on the road entering the intersection, the controller  16  recognizes the painted right-turn arrows c 1  and c 2  and thus recognizes right-turn lanes. Where stop lines d 1  and d 2  are painted on the road entering the intersection, the controller  16  recognizes the painted stop lines d 1  and d 2  and thus recognizes stop positions in the lanes. 
     As illustrated in  FIG. 7 , upon recognizing the line markings a 1  and a 2  for the right turn only lane that enters the intersection from the east-direction, the controller  16  recognizes the line markings a 1  and a 2  and generates travel trajectory data L 1  turning right within the intersection that follows the recognized line markings a 1  and a 2 . The controller  16  may correct a position of the travel trajectory data L 1  with reference to the recognized right-turn arrows or the stop lines in compliance with the traffic laws. Upon generating the travel trajectory data L 1 , the controller  16  complements connections at both ends of the generated travel trajectory data L 1  such that the travel trajectory data L 1  is smoothly connected to the travel trajectory data between intersections L 2  at the entrance-to-intersection end of the travel trajectory data L 1  and the travel trajectory data L 1  is smoothly connected to the travel trajectory data between intersections L 3  at the exit-from-intersection end of the travel trajectory data L 1 , thereby correcting the shape and location of the travel trajectory data L 1 . Any methods, such as Lagrange interpolation, Newtonian interpolation, spline interpolation or the like, may be employed to complement the connections. 
     Similarly, upon recognizing the line markings a 3  and a 4  for the right turn only lane that enters the intersection from the west-direction, the controller  16  recognizes the line markings a 3  and a 4  and generates travel trajectory data L 4  turning right within the intersection that follows the recognized line markings a 3  and a 4 . Upon generating the travel trajectory data L 4 , the controller  16  complements connections at both ends of the generated travel trajectory data L 4  such that the travel trajectory data L 4  is smoothly connected to the travel trajectory data between intersections L 5  at the entrance-to-intersection end of the travel trajectory data L 4  and the travel trajectory data L 4  is smoothly connected to the travel trajectory data between intersections L 6  at the exit-from-intersection end of the travel trajectory data L 4 , thereby correcting the shape and location of the travel trajectory data L 4 . 
     (2) Process of Generating Travel Trajectory Data by Recognizing Areas of Specific Colors on a Road in an Intersection 
       FIG. 8  illustrates an example of an intersection where the north-south direction road is a two-way road having two lanes for each direction and the east-west direction road is a two-way road having three lanes for each direction. The east-west direction road has a right turn only lane for each direction. 
     As illustrated in  FIG. 9 , the controller  16  performs the recognition process. Upon recognizing areas of specific colors on a road in an intersection (at S 31 ), the controller  16  generates the travel trajectory data in the intersection in response to a recognition result (at S 32 ). Upon generating the travel trajectory data in the intersection, the controller  16  complements connections at both ends of the generated travel trajectory data such that the travel trajectory data is smoothly connected to the travel trajectory data between intersections at both the entrance-to-intersection end and exit-from-intersection end of the travel trajectory data, thereby correcting the shape and location of the travel trajectory data (at S 33 ). 
     That is, where an area of specific color b 1  (indicated by a dotted area in  FIG. 8 ) is painted on the road in the intersection for the right turn only lane entering the intersection from the east-direction, the controller  16  recognizes the painted area of specific color b 1 . Similarly, where an area of specific color b 2  is painted on the road in the intersection for the right turn only lane that the controller  16  entering the intersection from the west-direction, the controller  16  recognizes the area of specific color b 2 . 
     Where striped areas e 1  and e 2  are painted on the road in the intersection, the controller  16  recognizes the painted striped areas e 1  and e 2  and thus recognizes the no-entry area for the vehicle. Where a diamond-shaped marking f 1  is painted on the road in the intersection, the controller  16  recognizes the diamond-shaped marking and thus recognizes an approach direction for the vehicle. Where right-turn arrows c 1  and c 2  are painted on the road entering an intersection, the controller  16  recognizes the painted right-turn arrows c 1  and c 2  and thus recognizes right-turn lanes. Where stop lines d 1  and d 2  are painted on the road entering the intersection, the controller  16  recognizes the painted stop lines d 1  and d 2  and thus recognizes stop positions in the lanes. 
     As illustrated in  FIG. 10 , upon recognizing the area of specific color b 1  for the right turn only lane that enters the intersection from the east-direction, the controller  16  generates travel trajectory data L 11  turning right in the intersection that follows the recognized area of specific color b 1 . Again, the controller  16  may correct a position of the travel trajectory data L 11  with reference to the recognized right-turn arrows or the stop lines in compliance with the traffic laws. Upon generating the travel trajectory data L 11 , the controller  16  complements connections at both ends of the generated travel trajectory data L 11  such that the travel trajectory data L 11  is smoothly connected to the travel trajectory data between intersections L 12  at the entrance-to-intersection end of the travel trajectory data L 11  and the travel trajectory data L 11  is smoothly connected to the travel trajectory data between intersections L 13  at the exit-from-intersection end of the travel trajectory data L 11 , thereby correcting the shape and location of the travel trajectory data L 1 . Any methods, such as Lagrange interpolation, Newtonian interpolation, spline interpolation or the like, may be employed to complement the connections. 
     Similarly, upon recognizing the area of specific color b 2  for the right turn only lane that enters the intersection from the west-direction, the controller  16  recognizes the area of specific color b 2  and generates travel trajectory data L 14  turning right within the intersection that follows the recognized area of specific color b 2 . Upon generating the travel trajectory data L 14 , the controller  16  complements connections at both ends of the generated travel trajectory data L 14  such that the travel trajectory data L 14  is smoothly connected to the travel trajectory data between intersections L 15  at the entrance-to-intersection end of the travel trajectory data L 14  and the travel trajectory data L 14  is smoothly connected to the travel trajectory data between intersections L 16  at the exit-from-intersection end of the travel trajectory data L 14 , thereby correcting the shape and location of the travel trajectory data L 14 . 
     (3) Process of Generating Travel Trajectory Data by Recognizing Striped Areas on a Road in an Intersection 
       FIG. 11  illustrates an example of a T-shaped intersection where the east-west direction road is a two-way road having two lanes for each direction and has a right turn only lane. 
     As illustrated in  FIG. 12 , the controller  16  performs the recognition process. Upon recognizing striped areas on a road in an intersection (at S 41 ), the controller  16  extracts frame portions of the recognized striped areas that contribute to a right turn (at S 42 ). Upon extracting the frame portions of the recognized striped areas that contribute to a right turn, the controller  16  recognizes shapes of the extracted frame portions (at S 43 ) and generates the travel trajectory data in the intersection in response to a recognition result (at S 44 ). Upon generating the travel trajectory data in the intersection, the controller  16  complements connections at both ends of the generated travel trajectory data such that the travel trajectory data is smoothly connected to the travel trajectory data between intersections at both the entrance-to-intersection end and exit-from-intersection end of the travel trajectory data, thereby correcting the shape and location of the travel trajectory data (at S 45 ). 
     That is, as illustrated in  FIG. 13 , upon recognizing the striped areas e 3  to e 5  for the right turn only lane that enters the intersection from the east-direction, the controller  16  extracts frame portions of the recognized striped areas e 3  to e 5  that contribute to a right turn and recognizes shapes of the extracted frame portions. More specifically, the controller  16  recognizes shapes of the frame portion p 1 -p 2  of the striped area e 3 , the frame portion p 3 -p 4  of the striped area e 4 , and the frame portion p 5 -p 6  of the striped area e 5 . 
     Upon recognizing the frame portions p 1 -p 2 , p 3 -p 4 , and p 5 -p 6  of the striped areas e 3  to e 5 , which contribute to a right turn, for the right turn only lane that enters the intersection from the east-direction, the controller  16  generates travel trajectory data L 21  turning right within the intersection that follows the recognized frame portions p 1 -p 2 , p 3 -p 4 , and p 5 -p 6 . Upon generating the travel trajectory data L 21 , the controller  16  complements connections at both ends of the generated travel trajectory data L 21  such that the travel trajectory data L 21  is smoothly connected to the travel trajectory data between intersections L 22  at the entrance-to-intersection end of the travel trajectory data L 21  and the travel trajectory data L 21  is smoothly connected to the travel trajectory data between intersections L 23  at the exit-from-intersection end of the travel trajectory data L 21 , thereby correcting the shape and location of the travel trajectory data L 21 . Any methods, such as Lagrange interpolation, Newtonian interpolation, spline interpolation or the like, may be employed to complement the connections. 
     (4) Process of Generating Travel Trajectory Data by Recognizing a Diamond-Shaped Marking on a Road in an Intersection 
       FIG. 14  illustrates an example of an intersection where the north-south direction road is a two-way road having two lanes for each direction and the east-west direction road is a two-way road having two lanes for each direction. The east-west direction road has a right turn only lane for each direction. 
     As illustrated in  FIG. 15 , upon recognizing a diamond-shaped marking on a road in an intersection (at S 51 ) by performing the recognition process, the controller  16  extracts a frame portion of the recognized diamond-shaped marking that contributes to a right turn (at S 52 ). Upon extracting the frame portion of the recognized diamond-shaped marking that contributes to a right turn, the controller  16  recognizes a shape of the extracted frame portion (at S 53 ) and generates the travel trajectory data in the intersection in response to a recognition result (at S 54 ). Upon generating the travel trajectory data in the intersection, the controller  16  complements connections at both ends of the generated travel trajectory data such that the travel trajectory data is smoothly connected to the travel trajectory data between intersections at both the entrance-to-intersection end and exit-from-intersection end of the travel trajectory data, thereby correcting the shape and location of the travel trajectory data (at S 55 ). 
     That is, as illustrated in  FIG. 16 , upon recognizing the diamond-shaped marking f 2  for the right turn only lane that enters the intersection from the east-direction, the controller  16  extracts a frame portion of the recognized diamond-shaped marking f 2  that contributes to a right turn and recognizes a shape of the extracted frame portion. More specifically, the controller  16  recognizes a shape of the frame portion p 11 -p 12  of the diamond-shaped marking f 2 . 
     Upon recognizing the frame portion p 11 -p 12  of the diamond-shaped marking f 2 , which contributes to a right turn, for the right turn only lane that enters the intersection from the east-direction, the controller  16  generates travel trajectory data L 31  turning right within the intersection that follows the recognized frame portion p 11 -p 12 . Upon generating the travel trajectory data L 31 , the controller  16  complements connections at both ends of the generated travel trajectory data L 31  such that the travel trajectory data L 31  is smoothly connected to the travel trajectory data between intersections L 32  at the entrance-to-intersection end of the travel trajectory data L 31  and the travel trajectory data L 31  is smoothly connected to the travel trajectory data between intersections L 33  at the exit-from-intersection end of the travel trajectory data L 31 , thereby correcting the shape and location of the travel trajectory data L 31 . Any methods, such as Lagrange interpolation, Newtonian interpolation, spline interpolation or the like, may be employed to complement the connections. 
     In the above, it has been assumed that the vehicle is traveling in an area to which a road traffic act that regulates left-hand traffic is applied. Instead, it may be assumed that the vehicle is traveling in an area to which a road traffic act that regulates right-hand traffic is applied. In this case, the vehicle has to cross oncoming lanes to make a left turn. The controller  16  may therefore generate travel trajectory data turning left within an intersection. In addition, in the above, a line marking, an area of specific color, a striped area, and a diamond-shaped marking on a road in an intersection are individually recognized. Instead, a line marking, an area of specific color, a striped area, and a diamond-shaped marking on a road in an intersection may be recognized in combination to generate travel trajectory data. 
     Also when recognizing a roundabout, the controller  16  generates travel trajectory data in the outermost circular lane of the roundabout.  FIG. 17  illustrates an example where the roundabout is connected to roads in four directions. As illustrated in  FIG. 18 , upon recognizing a roundabout by performing the recognition process (at S 61 ), the controller  16  extracts the outermost circular lane of the recognized roundabout (at S 62 ). The controller  16  generates clockwise travel trajectory data in the extracted outermost circular lane (at S 63 ). Upon generating travel trajectory data in the intersection, the controller  16  complements connections at predefined positions (eight positions) along the generated travel trajectory data such that the travel trajectory data is smoothly connected to the travel trajectory data between intersections at both the entrance-to-intersection end and exit-from-intersection end of the travel trajectory data, thereby correcting the shape and location of the travel trajectory data (at S 64 ). 
     As illustrated in  FIG. 19 , the controller  16  generates clockwise travel trajectory data L 41  in the outermost circular lane of the roundabout. Upon generating the travel trajectory data L 41 , the controller  16  complements connections at predefined positions (eight positions x 1  to x 8  illustrated in  FIG. 19 ) along the generated travel trajectory data L 41  such that the travel trajectory data L 41  is smoothly connected to the travel trajectory data between intersections L 42  to L 45  at the entrance-to-intersection points and the travel trajectory data L 41  is smoothly connected to the travel trajectory data between intersections L 46  to L 49  at the exit-from-intersection points, thereby correcting the shape and location of the travel trajectory data L 41 . In this case as well, the technique for complementing connections may be any technique, such as Lagrange interpolation, Newtonian interpolation, spline interpolation or the like. As above, it has been assumed that the vehicle is traveling in an area to which a road traffic act that regulates left-hand traffic is applied. Instead, it may be assumed that the vehicle is traveling in an area to which a road traffic act that regulates right-hand traffic is applied, where the controller  16  generates counterclockwise travel trajectory data in the outermost circular lane of the roundabout. 
     The present embodiment set forth above can provide the following advantages. 
     The controller  16  recognizes channelizing strips on a road in an intersection from aerial photo data, satellite photo data, and vehicle image data, and generates travel trajectory data in the intersection for autonomous driving in response to a recognition result. Where channelizing strips are actually existing on a road in an intersection, generating the travel trajectory data in the intersection for autonomous driving in response to the actually existing channelizing strips enables appropriate generation of travel trajectory data in the intersection for autonomous driving. 
     The controller  16  recognizes line markings on a road in an intersection as channelizing strips and generates travel trajectory data that follows the recognized line markings. With this, for an intersection where line markings are painted, the travel trajectory data in the intersection for autonomous driving can appropriately be generated. 
     The controller  16  recognizes areas of specific colors on a road in an intersection as channelizing strips and generates travel trajectory data that follows the recognized areas. With this, for an intersection where areas of specific colors are painted, the travel trajectory data in the intersection for autonomous driving can appropriately be generated. 
     The controller  16  recognizes striped areas in an intersection as channelizing strips and generates travel trajectory data that follows shapes of the striped areas. With this, for an intersection where striped areas are painted, the travel trajectory data in the intersection for autonomous driving can appropriately be generated. 
     The controller  16  recognizes a diamond-shaped marking in an intersection as channelizing strips and generates travel trajectory data that follows a shape of the diamond-shaped marking. With this, for an intersection where a diamond-shaped marking is painted, the travel trajectory data in the intersection for autonomous driving can appropriately be generated. 
     The controller  16  performs, as a pre-detection process, brightness adjustment, roadside tree masking, and vehicle detection, and recognizes channelizing strips on a road in an intersection from aerial photo data, satellite photo data, and vehicle image data that were processed in the pre-detection process. Performing the pre-detection process allows the channelizing strips to be recognized after removing unnecessary information, and can improve the accuracy of recognition of channelizing strips. 
     The controller  16  performs, as a detection process, white-line intensity calculation, noise masking, white-line center detection, and white-line information generation, and recognizes channelizing strips on a road in an intersection from aerial photo data, satellite photo data, and vehicle image data that were processed in the detection process. Performing the detection process allows the channelizing strips to be recognized after emphasizing necessary information and removing unnecessary information, and can improve the accuracy of recognition of channelizing strips. 
     The present disclosure is described in compliance with the embodiments. However, it should be appreciated that the present disclosure is not limited to the embodiments set forth above or the structures thereof. The present disclosure encompasses various modified examples and modifications within the range of equivalency. In addition, the scope of the present disclosure and the range of ideas thereof include various combinations and forms and other combinations and forms additionally including one or more elements or a portion of one element. 
     The channelizing strips may be recognized using any one of the aerial photo data, the satellite photo data, and the vehicle image data, or may be recognized using all of them. 
     In the exemplary embodiment set forth above, the vehicle image data is transmitted from the vehicle-mounted device  2  to the map data generation device  3 . In the map data generation device  3 , the vehicle image data received from the vehicle-mounted device  2  is image-recognized. In an alternative embodiment, some or all of the image recognition process performed by the map data generation device  3  may be performed by the vehicle-mounted device  2 . That is, in the vehicle-mounted device  2 , for example, the vehicle image data is image-recognized to generate analysis result data indicating location coordinates and installation modes of the road markings, such as the channelizing strips or the like. The generated analysis result data may be transmitted to the map data generation device  3 . In the map data generation device  3 , road information data and travel trajectory data may be generated using the analysis result data received from the vehicle-mounted device  2 . With the configuration where the analysis result data is transmitted from the vehicle-mounted device  2  to the map data generation device  3 , an amount of data communication from the vehicle-mounted device  2  to the map data generation device  3  can be suppressed and the processing load of the map data generation device  3  can be reduced. 
     The configuration is not limited to the configuration where the brightness adjustment, the roadside tree masking and the vehicle detection are performed as the pre-detection process, but any of them may be performed, or another process may be performed as the pre-detection process. 
     The configuration is not limited to the configuration where the white line intensity calculation, the noise masking, the white-line center detection, and the white-line information generation are performed as the detection process, but any of them may be performed, or another process may be performed as the detection process. 
     The shape of the intersection is not limited to the illustrated shape. 
     The controller and its method described in relation to the present disclosure may be implemented by a dedicated computer that is provided by forming a processor and a memory programmed to execute one or more functions embodied by a computer program. Otherwise, the controller and its method described in relation to the present disclosure may be implemented by a dedicated computer that is provided by forming a processor from one or more dedicated hardware logic circuits. Alternatively, the controller and its method described in relation to the present disclosure may be implemented by one or more dedicated computers that are formed by a combination of a processor and a memory programmed to execute one or more functions and one or more hardware logic circuits. The computer program may be stored as instructions to be executed by a computer in a computer-readable non-transitory tangible recording medium.