JP2007274564A - Calibration apparatus and calibration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily correct a mounting angle of an imaging unit and to improve correction accuracy. <P>SOLUTION: A calibration apparatus includes: a vehicle-mounted camera; a light emitting device which is mounted in the vehicle-mounted camera and irradiates the ground to form a marker on the ground; a marker photographing processing means for photographing the marker by means of the vehicle-mounted camera; an image recognition processing means for recognizing the marker from an image of the marker; and a mounting angle calculation processing means for calculating a mounting angle of the camera on the basis of the recognized marker. The ground is irradiated with the light emitting device to form the marker on the ground, the marker is photographed by the vehicle-mounted camera and the mounting angle of the camera is calculated on the basis of the recognized marker. Thus, it is not necessary to manually set a position to form the marker and not only operation can be simplified but also correction accuracy can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a calibration apparatus and a calibration method.

  Conventionally, in a navigation device, for example, the current position of a vehicle, that is, the current location, is detected by GPS (global positioning system), map data is read from a data recording unit, a map screen is formed on a display unit, The map screen displays a vehicle position indicating the current location, a map around the vehicle position, and the like. Therefore, the driver who is an operator can drive the vehicle according to the vehicle position displayed on the map screen.

  When the driver inputs a destination and sets search conditions, a route search process is performed based on the search conditions, and a route from the starting point represented by the current location to the destination is searched according to the map data. Is done. Then, the searched route, that is, the searched route is displayed on the map screen together with the vehicle position, and guidance for the searched route, that is, route guidance is performed. Therefore, the driver can drive the vehicle along the displayed search route.

  By the way, for example, in order to monitor the surroundings of a vehicle, a camera as an imaging device is attached with the optical axis directed obliquely downward, and an object to be photographed such as a feature, another vehicle, a roadside structure, or a structure. And the object to be photographed in the image is recognized (see, for example, Patent Document 1).

In order to mount the camera at an accurate mounting angle or change the mounting angle, a marker is placed at a fixed position on the road, and the mounting angle is corrected while shooting the marker with the camera.
JP-A-8-16999

  However, in the conventional camera, it is necessary to manually set the position where the marker is placed, which is not only troublesome but also reduces the accuracy of correction.

  The present invention provides a calibration device and a calibration method that can solve the problems of the conventional camera and can easily correct the mounting angle of the imaging device and increase the accuracy of the correction. For the purpose.

  Therefore, in the calibration device of the present invention, a vehicle-mounted camera, a light-emitting device that is attached to the vehicle-mounted camera and that irradiates the ground to form a marker on the ground, and a marker photographing process that photographs the marker with the vehicle-mounted camera Means, image recognition processing means for recognizing a marker from the image of the marker, and attachment angle calculation processing means for calculating a camera attachment angle based on the recognized marker.

  According to the present invention, the ground is irradiated by the light emitting device, the marker is formed on the ground, the marker is photographed by the in-vehicle camera, the marker is recognized from the marker image, and the camera is attached based on the recognized marker. Since the angle is calculated, it is not necessary to manually set the position where the marker is formed, and not only can the operation be simplified, but also the correction accuracy can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a navigation system according to an embodiment of the present invention.

  In the figure, reference numeral 10 denotes an automatic transmission control unit as a power train control unit. The automatic transmission control unit 10 is a power train that performs a shift at a predetermined gear ratio, for example, a continuously variable transmission as an automatic transmission. (CVT), stepped transmission (automatic transmission), electric drive device, etc. are controlled.

  Reference numeral 14 is an information terminal, for example, a navigation device as an in-vehicle device mounted on a vehicle, 63 is a network, 51 is an information center as an information provider, and the automatic transmission control unit 10, the navigation device 14, the network 63, the information center 51 and the like constitute a navigation system.

  The navigation device 14 constitutes a GPS (Global Positioning System), a GPS sensor 15 as a current location detection unit for detecting the current location of the vehicle, and data as an information recording unit in which various information is recorded in addition to map data. The recording unit 16, a navigation processing unit 17 that performs various arithmetic processing such as navigation processing based on the input information, a direction sensor 18 as a direction detection unit that detects the vehicle direction, and a driver who is an operator is predetermined. A display unit 35 as a first output unit for performing various displays by an image displayed on a screen (not shown) and notifying a driver, The voice input unit 36 as a second input unit for performing predetermined input by voice, various displays by voice, and notification to the driver A voice output unit 37 as a second output unit, and a communication unit 38 as a transmission / reception unit functioning as a communication terminal. The navigation processing unit 17 includes a GPS sensor 15, a data recording unit 16, an orientation sensor 18, An operation unit 34, a display unit 35, a voice input unit 36, a voice output unit 37, and a communication unit 38 are connected.

  The navigation processing unit 17 is attached to the automatic transmission control unit 10, a predetermined position at the front end of the vehicle, and a front monitoring device 48 for monitoring the front of the vehicle, and a predetermined position at the rear end of the vehicle. As an imaging device that captures the rear of the vehicle, a back camera (rear monitoring camera) 49 as an in-vehicle camera, and an engine load detection unit that detects an operation of an accelerator pedal (not shown) by a driver by an accelerator opening. An accelerator sensor 42, a brake sensor 43 as a brake detection unit that detects an operation of a brake pedal (not shown) by a driver by a brake depression amount, a vehicle speed sensor 44 as a vehicle speed detection unit that detects a vehicle speed, and the like are connected.

  The accelerator sensor 42, the brake sensor 43, and the like constitute an operation information detection unit for detecting vehicle operation information by the driver. In addition, various in-vehicle cameras such as a front camera that captures the front of the vehicle (front monitoring camera) and a side camera that monitors the side of the vehicle can be used as the imaging device. Further, the back camera 49 includes an angle adjustment mechanism so that the attachment angle can be changed.

  The GPS sensor 15 detects the current location on the earth by receiving radio waves generated by an artificial satellite, and also detects the time. In the present embodiment, the GPS sensor 15 is used as the current position detection unit. However, in place of the GPS sensor 15, a distance sensor, a steering sensor, an altimeter, etc. (not shown) are used alone or in combination. You can also Further, a gyro sensor, a geomagnetic sensor, or the like can be used as the direction sensor 18. In the present embodiment, the azimuth sensor 18 and the vehicle speed sensor 44 are arranged. However, when a GPS sensor having a function of detecting the vehicle azimuth, the vehicle speed, etc. is used, the azimuth sensor 18. The vehicle speed sensor 44 and the like are not necessary.

  The data recording unit 16 includes a map database including map data files, and map data is recorded in the map database. The map data includes intersection data relating to intersections, node data relating to nodes, road data relating to road links, search data processed for searching, facility data relating to facilities, and feature data relating to features on the road. Is included.

  The feature is a display object that is installed or formed on a road in order to provide various driving information to the driver or to perform various driving guidance. , Crosswalks, manhole covers, traffic lights, etc. The display line includes a stop line for stopping a vehicle on the road, a vehicle lane boundary line that divides each lane, a partition line that indicates a parking space, and the road sign is formed on each lane. Traffic stop signs indicating the direction of travel in the lane with arrows, temporary stop points such as “stop” (including non-priority road entry to priority road, railroad crossings, intersections where a red light flashes, etc.) And a guidance sign that is formed on each lane and provides guidance in the direction of the lane, such as “direction XX”. The vehicle lane boundary line includes a road boundary line formed by a solid line on the shoulder side and the opposite lane side of the road, and a lane boundary formed by a broken line between each lane in a region sandwiched between the road boundary lines. Includes lines.

  The feature data includes position information that represents the position of each feature by coordinates, image information that represents each feature by image, and the like. When a radio wave beacon device, an optical beacon device, etc., which will be described later, are regarded as features, the current traffic information is sent to the vehicle with a different signal for each lane. Therefore, a signal sent from a radio beacon device, an optical beacon device, or the like is also included in the feature data.

  The intersection data includes the name of the intersection, the road entering the guidance intersection (hereinafter referred to as “entrance road”), the road exiting from the guidance intersection (hereinafter referred to as “exit road”), the presence / absence of a traffic signal, and the type of traffic signal ( For example, data such as a sensitive signal) is included. For example, when the traffic light is a sensitive traffic light, data indicating the position of a sensing area that is a vehicle detection area by the vehicle sensing sensor is included.

  The road data relating to the lane includes lane data (lane information) including the number of lanes indicating the number of lanes of the road, the lane number assigned to each lane on the road, lane position information, and the like.

  The data recording unit 16 also records data for outputting predetermined information by the audio output unit 37.

  Further, the data recording unit 16 includes a statistical database composed of statistical data files, a travel history database composed of travel history data files, and the like. Statistical data is stored in the statistical data file, and travel history data is stored in the travel history data file. However, both are recorded as performance data.

  The statistical data is a history of traffic information provided in the past, that is, history information representing a history, and a road traffic information center (not shown) such as a VICS (registered trademark: Vehicle Information and Communication System) center as an information provider. Traffic information provided in the past, etc., road traffic census information that is data representing traffic volume by road traffic census provided by the Ministry of Land, Infrastructure, Transport and Tourism, road timetable information provided by the Ministry of Land, Infrastructure, Transport and Tourism alone, or It is created by using in combination, processing as needed, and applying statistical processing. It is possible to add traffic jam prediction information for predicting traffic jams to the statistical data. In that case, in creating the statistical data, detailed conditions such as date and time, day of the week, weather, various events, seasons, facility information (presence / absence of large facilities such as department stores and supermarkets) are added to the history information.

  The data items of the statistical data include a link number for each road link, a direction flag that represents a traveling direction, an information type that represents a type of information, a degree of congestion at each predetermined timing, and a time when the road link is traveled. , A link required time representing a required time for each predetermined timing, and average data for each day of the link required time, for example, day average data.

  Further, the travel history data is collected from a plurality of vehicles, that is, the own vehicle or other vehicles by the information center 51, and is a track record that represents the track record of the vehicle on the road on which each vehicle has traveled, that is, the track record. The probe data is calculated and accumulated based on the travel data.

  The data items of the travel history data include a link required time at each predetermined timing when traveling on each road link, a degree of congestion at each predetermined timing when traveling on each road link, and the like. Note that travel history data can be added to the statistical data. Further, in the present embodiment, the congestion level is used as a congestion index that represents the degree of congestion, and is represented separately for congestion, congestion, and non-congestion.

  The data recording unit 16 includes a disk (not shown) such as a hard disk, a CD, a DVD, and an optical disk in order to record the various data, and also reads / writes for reading and writing various data. A head (not shown) such as a head is provided. Further, a memory card or the like can be used for the data recording unit 16. An external storage device is constituted by the disks, memory cards and the like.

  In the present embodiment, the map database, the statistical database, the travel history database, and the like are formed in the data recording unit 16, but in the information center 51, the map database, the statistical database, the travel history A database or the like can also be formed.

  The navigation processing unit 17 is a control device that performs overall control of the navigation device 14 and a CPU 31 as an arithmetic device, a RAM 32 that is used as a working memory when the CPU 31 performs various arithmetic processes, In addition to the above program, a ROM 33 in which various programs for searching for a route to the destination, route guidance and the like are recorded, and a flash memory (not shown) used for recording various data, programs and the like are provided. . The RAM 32, ROM 33, flash memory, etc. constitute an internal storage device.

  In the present embodiment, various programs can be recorded in the ROM 33 and various data can be recorded in the data recording unit 16, but the programs, data, and the like can also be recorded on a disk or the like. In this case, the program, data, etc. can be read from a disk or the like and written to the flash memory. Therefore, the program, data, etc. can be updated by exchanging the disk or the like. Further, the control program, data, and the like of the automatic transmission control unit 10 can be recorded on the disk or the like. Further, the program, data, and the like can be received via the communication unit 38 and written into the flash memory of the navigation processing unit 17.

  The operation unit 34 is operated by the driver to correct the current location at the start of traveling, to input a departure point and a destination, to input a passing point, and to activate the communication unit 38. As the operation unit 34, a keyboard, a mouse, or the like disposed independently of the display unit 35 can be used. Further, as the operation unit 34, a predetermined input operation is performed by touching or clicking an image operation unit such as various keys, switches, and buttons displayed as images on the screen formed in the display unit 35. It is possible to use a touch panel that can be used.

  A display is used as the display unit 35. Then, on various screens formed on the display unit 35, the current position of the vehicle is displayed as the vehicle position, the vehicle direction is displayed as the vehicle direction, a map, a search route, guidance information along the search route, traffic In addition to displaying information and the like, displaying the distance to the next intersection on the searched route, and the traveling direction at the next intersection, the operation of the image operation unit, operation unit 34, voice input unit 36, etc. It is possible to display guidance, operation menus and key guidance, and to display FM multiplex broadcast programs.

  The voice input unit 36 includes a microphone (not shown) and the like, and can input necessary information by voice. Further, the voice output unit 37 includes a voice synthesizer and a speaker (not shown), and the search route, guidance information, traffic information, and the like are output from the voice output unit 37, for example, as voice synthesized by the voice synthesizer. .

  The communication unit 38 transmits various information such as current traffic information and general information transmitted from the road traffic information center to radio wave beacons via radio wave beacon devices, optical beacon devices and the like arranged along the road. A beacon receiver for receiving as an optical beacon, an FM receiver for receiving as an FM multiplex broadcast via an FM broadcast station, and the like. The traffic information includes traffic jam information, regulation information, parking lot information, traffic accident information, service area congestion status information, and the like, and general information includes news, weather forecasts, and the like. Further, the beacon receiver and the FM receiver are unitized and arranged as a VICS receiver, but can be arranged separately.

  The traffic information includes an information type indicating a type of information, a mesh number for specifying a mesh, a link number that specifies two points, for example, a road link that connects between intersections, and indicates a link between uplink and downlink , Including link information representing the content of information provided in association with the link number, for example, when the traffic information is traffic jam information, the link information is a distance from the start point of the road link to the head of the traffic jam Congestion head data representing traffic congestion degree, congestion section, traffic jam length representing the distance from the beginning of the traffic jam to the end of the traffic jam, link required time representing the time required to travel on the road link, and the like.

  And the communication part 38 can receive various information, such as traffic information and general information other than data, such as the said map data, statistical data, and driving history data, from the said information center 51 via the network 63. .

  For this purpose, the information center 51 includes a server 53, a communication unit 57 connected to the server 53, a database (DB) 58 as an information recording unit, and the like. A CPU 54, a RAM 55, a ROM 56, etc. are provided as devices. The database 58 records data similar to the various data recorded in the data recording unit 16, for example, the map data, statistical data, travel history data, and the like. Further, the information center 51 provides various information such as current traffic information and general information transmitted from the road traffic information center, and travel history data collected from a plurality of vehicles (own vehicle or other vehicles) in real time. can do.

  The forward monitoring device 48 is composed of a radar such as a laser radar or a millimeter wave radar, an ultrasonic sensor, or a combination thereof, and monitors a vehicle traveling ahead, that is, a preceding vehicle, Monitor stop points and obstacles. Further, the front monitoring device 48 detects a relative speed indicating a relative vehicle speed with respect to the preceding vehicle, an approach speed with respect to a temporary stop position, an approach speed with respect to an obstacle, and the like, and calculates an inter-vehicle distance, an inter-vehicle time, etc. To do.

  The back camera 49 is composed of a CCD element and is mounted with the optical axis obliquely downward to monitor the rear of the vehicle. In addition to the features, the rear camera 49 is a vehicle traveling behind the vehicle. Vehicles, roadside buildings, structures, and the like are photographed as objects to be photographed, and image data of the photographed objects are generated and sent to the CPU 31. The CPU 31 reads the image data and performs image processing on the image data, thereby recognizing each object to be photographed in the image as a recognition object. In the present embodiment, a CCD element is used as the back camera 49, but a C-MOS element or the like can be used.

  The navigation system, the navigation processing unit 17, the CPUs 31, 54, the server 53, and the like function as a computer alone or in combination of two or more, and perform arithmetic processing based on various programs, data, and the like. The data recording unit 16, RAMs 32 and 55, ROMs 33 and 56, database 58, flash memory, and the like constitute a recording medium. An MPU or the like can be used instead of the CPUs 31 and 54 as the arithmetic unit.

  Next, a basic operation of the navigation system having the above configuration will be described.

  First, when the operation unit 34 is operated by the driver and the navigation device 14 is activated, a navigation initialization processing unit (not shown) of the CPU 31 performs navigation initialization processing, and the current location of the vehicle detected by the GPS sensor 15, The vehicle direction detected by the direction sensor 18 is read, and various data are initialized. Next, the matching processing means (not shown) of the CPU 31 performs matching processing, reads the current location, and based on the trajectory of the read current location and the shape, arrangement, etc. of each road link constituting the road around the current location, The current location is identified by determining on which road link the current location is located.

  In the present embodiment, the matching processing unit further specifies the current location based on the position of each feature that is the subject to be photographed by the back camera 49. Note that in a vehicle including a front camera that captures the front of the vehicle, the position of each feature can be calculated by the front camera.

  For this purpose, image recognition processing means (not shown) of the CPU 31 performs image recognition processing, reads image data from the back camera 49, and recognizes a feature in the image composed of the image data. A distance calculation processing unit (not shown) of the CPU 31 performs a distance calculation process, and calculates a distance from the back camera 49 to the actual feature based on the position of the feature in the image. The current location specifying processing means of the matching processing means performs current location specifying processing, reads the distance, reads the feature data from the data recording unit 16 to acquire the coordinates of the feature, and the coordinates and the distance Based on the current location.

  A lane identification processing unit (not shown) of the CPU 31 performs a lane identification process, and records features and data as necessary based on the travel history of the lane, the features recognized based on the image data, and the like. Based on the collation result when collating with the feature data read from the unit 16, the traveling lane is specified. Furthermore, a high-precision GPS sensor can be used to accurately detect the current location, and the traveling lane can be specified based on the detection result.

  When the feature is made of a ferromagnetic material such as steel such as a manhole cover, the lane identification processing unit reads the sensor output of the geomagnetic sensor, and there is a manhole cover or the like based on the sensor output. It is also possible to determine whether or not the vehicle lane is based on the determination result. Further, if necessary, it is possible to identify the traveling lane by combining the sensor output of the geomagnetic sensor, the current location, etc. simultaneously with performing image processing on the image data of the display lines.

  Subsequently, a basic information acquisition processing unit (not shown) of the CPU 31 performs a basic information acquisition process and acquires the map data by reading it from the data recording unit 16 or receiving it from the information center 51 or the like via the communication unit 38. And get. In addition, when acquiring map data from the information center 51 etc., the said basic information acquisition process means downloads the received map data to flash memory.

  A display processing unit (not shown) of the CPU 31 performs display processing and forms various screens on the display unit 35. For example, the map display processing means of the display processing means performs a map display process, forms a map screen on the display unit 35, displays a surrounding map on the map screen, and sets the current position as the vehicle position and the direction of the vehicle. Is displayed as the vehicle direction.

  Accordingly, the driver can drive the vehicle according to the map, the vehicle position, and the vehicle direction.

  Further, when the driver operates the operation unit 34 to input a destination, a destination setting processing unit (not shown) of the CPU 31 performs a destination setting process to set the destination. Note that the departure place can be input and set as necessary. Moreover, a predetermined point can be registered in advance, and the registered point can be set as a destination. Subsequently, when the driver operates the operation unit 34 to input a search condition, a search condition setting processing unit (not shown) of the CPU 31 performs a search condition setting process to set the search condition.

  When the destination and the search condition are set in this way, the route search processing unit (not shown) of the CPU 31 performs the route search process, reads the current location, the destination, the search condition, and the like from the data recording unit 16. Based on the current location, the destination, and the search data, a route from the departure point to the destination represented by the current location is searched based on the search condition, and route data representing the searched route is output. At this time, the route with the smallest total link cost assigned to each road link is set as the searched route.

  In addition, when a plurality of lanes are formed on the road and a traveling lane is specified, the route search processing unit searches for a searched route for each lane. In this case, the route data includes the lane number of the traveling lane.

  The information center 51 can perform a route search process. In that case, the CPU 31 transmits the current location, the destination, search conditions, and the like to the information center 51. When the information center 51 receives the current location, destination, search conditions, etc., the route search processing means (not shown) of the CPU 54 performs route search processing similar to that of the CPU 31 and reads the search data from the database 58 to obtain the current location, destination. Based on the location and the search data, a route from the departure point to the destination is searched under the search conditions, and route data representing the searched route is output. Next, a transmission processing unit (not shown) of the CPU 54 performs transmission processing and transmits the route data to the navigation device 14.

  Subsequently, a guidance processing means (not shown) of the CPU 31 performs guidance processing and provides route guidance. For this purpose, the route display processing means of the guidance processing means performs route display processing, reads the route data, and displays the searched route on the map screen according to the route data.

  By the way, in the route guidance, when the vehicle needs to turn right or left at a predetermined intersection, the intersection is set as a guidance point and a guidance intersection.

  For this purpose, the guidance intersection setting processing means of the guidance processing means performs guidance intersection setting processing and determines whether there is an intersection that requires the vehicle to turn left or right according to the route data, that is, based on the searched route. If there is an intersection that requires the vehicle to turn left or right, the intersection is set as a guide intersection.

  In addition, when the searched route is searched for in each lane, the recommended lane setting processing unit of the guidance processing unit performs a recommended lane setting process and, as described above, a lane recommended to travel, for example, When passing through the guidance intersection, a lane suitable for entering the guidance intersection, a lane suitable for exiting the guidance intersection, and the like are selected and set as recommended lanes. The route display processing means displays the search route on the map screen, and displays an enlarged view of the road on which the vehicle is traveling, that is, an enlarged view of the road, in a predetermined area of the map screen. Lane guidance according to the figure. In this case, each lane and recommended lanes among the lanes are displayed on the enlarged road view.

  Subsequently, the voice output processing means of the guidance processing means performs voice output processing and outputs route guidance from the voice output unit 37 by voice. For this purpose, the route guidance point setting processing means of the guidance processing means performs route guidance point setting processing, at a location that is a predetermined distance away from the guidance intersection on the searched route (on the vehicle side). Set one or more route guidance points. Further, the point guidance processing means of the guidance processing means performs the point guidance processing, and when the vehicle reaches each route guidance point, the guidance intersection is preliminarily set for each route guidance point, for example, guidance from the own vehicle position. Route guidance is provided for distances to intersections, left and right turns at guidance intersections, etc. In addition, when a recommended lane is set, the lane guidance processing means of the point guidance processing means performs lane guidance processing, and contents set in advance for each route guidance point, for example, from the vehicle position to the guidance intersection For each recommended lane, the recommended lane ahead of the guidance intersection, etc., the lane guidance is provided by voice phrases. If the travel lane is different from the recommended lane, the lane guidance processing means guides the vehicle from the travel lane to the recommended lane. Therefore, the driver can drive the vehicle along the recommended lane.

  Further, the guidance point enlarged map display processing means of the guidance processing means performs the guidance point enlarged map display processing, reads the intersection data, and before the vehicle reaches the guidance intersection, the guidance point enlarged map display process is performed in a predetermined area of the map screen. An enlarged view, that is, an enlarged view of the intersection is displayed, and route guidance based on the enlarged view of the intersection is performed. In this case, a map of the vicinity of the guidance intersection, a search route, and landmarks such as facilities that are landmarks at the guidance intersection are displayed on the enlarged intersection. When a plurality of lanes are formed on the approach road or the exit road and the lane guidance is performed, the guide point enlarged map display processing means displays the recommended lane on the intersection enlarged map.

  By the way, as described above, for example, in order to monitor the surroundings of the own vehicle, the back camera 49 is mounted with the optical axis obliquely downward, and features, other vehicles, roadside structures, structures For example, a subject to be photographed in the image can be recognized.

  However, if the mounting angle of the back camera 49 is not accurate, the object to be photographed cannot be accurately recognized.

  Therefore, the mounting angle of the back camera 49 can be corrected by a calibration device.

  2 is a diagram illustrating the operation of the calibration apparatus according to the embodiment of the present invention, FIG. 3 is a perspective view of the back camera according to the embodiment of the present invention, and FIG. 4 is a diagram of the marker by the back camera according to the embodiment of the present invention. FIG. 5 is a diagram illustrating a shooting state, FIG. 5 is a first diagram illustrating a method for correcting the mounting angle in the embodiment of the present invention, and FIG. 6 is a second diagram illustrating a method for correcting the mounting angle in the embodiment of the present invention. is there.

  In this case, the back camera 49 includes a lens 71, a frame 72 that holds the lens 71, and the like, and the front end surface 73 of the frame 72 has a plurality of locations in the circumferential direction, that is, four locations in the present embodiment. Laser pointers qi (i = 1, 2,..., 4) as light emitting devices are attached at equal pitches.

  Then, a marker creation processing unit (not shown) of the CPU 31 performs a marker creation process, generates a laser beam by each pointer qi with the back camera 49 mounted on the own vehicle, irradiates the ground Se, and ground Se. On the top, a marker ki (i = 1, 2,..., 4) is formed at a position corresponding to each pointer qi. Although the pointer qi has a circular shape at the light source portion, the back camera 49 is mounted with its optical axis obliquely downward, so that each marker ki has a shape that is distorted and has an elliptical shape. Become.

  Subsequently, a marker photographing processing unit (not shown) of the CPU 31 performs a marker photographing process, photographs each marker ki with the back camera 49, generates image data of the photographed marker ki, and sends the image data to the CPU 31.

  The image recognition processing means performs image processing on the image data sent from the back camera 49 and recognizes each marker ki in the image. Subsequently, an attachment angle calculation processing unit (not shown) of the CPU 31 performs an attachment angle calculation process, and calculates the attachment angle of the back camera 49 based on the recognized size and shape of each marker ki. The calibration device includes a back camera 49, a pointer qi, a CPU 31, and the like.

  The vertical length of each pointer qi is ε1, the vertical distance between the pointers q1 and q3 (between the pointers q2 and q4) is ε2, and the horizontal length between the pointers q1 and q2 (between the pointers q3 and q4) is The distance is ε3, and as shown in FIG. 5, the vertical length of each marker ki is u1, the vertical distance between the markers k1 and k3 (between the markers k2 and k4) is u2, and the marker When the horizontal distance between k1 and k2 (between the markers k3 and k4) is u3, the mounting angle calculation processing means is a back camera based on the lengths u1, ε1 and the distances u2, u3, ε2, ε3. 49 is calculated.

The mounting angle of the back camera 49 can be expressed by an angle formed by the optical axis of the back camera 49 and a line extending vertically downward from the back camera 49. When the mounting angle is θ1, for example, from the distances u2 and ε2. θ1 = cos ⁻ (ε2 / u2)
It becomes.

  For example, when the back camera 49 is mounted at the correct mounting angle θ1, as shown in FIG. 5, the vertical length of each marker ki is u1, and the distance between the markers k1 and k3 (marker k2 , K4) in the vertical direction is u2, and the horizontal distance between the markers k1 and k2 (between the markers k3 and k4) is u13, whereas when the mounting angle is changed to θ2, For example, as shown in FIG. 6, the vertical length of each marker ki is u11, the vertical distance between the markers k1 and k3 (between the markers k2 and k4) is u12, and the markers k1 and k2 The horizontal distance between the markers (between markers k3 and k4) changes to u13. Therefore, the attachment angle calculation processing means calculates the attachment angle θ2 of the back camera 49 based on the length u11 and the distances u12 and u13.

Subsequently, the correction processing means of the CPU 31 performs correction processing, reads the mounting angles θ1, θ2, and calculates the difference angle Δθ.
Δθ = θ2-θ1
Only the mounting angle of the back camera 49 is changed. For this purpose, the attachment angle adjustment processing means (not shown) of the CPU 31 performs the attachment angle adjustment processing and operates the angle adjustment mechanism. The angle adjusting mechanism is disposed at a predetermined position of the vehicle, and includes a predetermined link, a motor as a drive unit, and the like. The link is operated by driving the motor, and the mounting angle of the back camera 49 is changed. .

  In this way, the mounting angle θ1 of the back camera 49 is detected and corrected based on the marker ki formed on the ground Se by each pointer qi, so there is no need to manually set the position where the marker ki is formed. Not only can the operation be simplified, but also the accuracy of correction can be increased.

  In addition, the pointers qi are disposed on the frame 72 of the back camera 49, and when the mounting angle of the back camera 49 changes, the shape, position, etc. of the marker ki change proportionally, so the mounting angles θ1, θ2 can be easily set. Can be calculated.

Next, a flowchart will be described.
Step S1: A marker ki is created on the ground with a laser pointer.
Step S2: The marker ki is photographed by the back camera 49.
Step S3 The mounting angles θ1 and θ2 of the back camera 49 are calculated according to the size and shape.
Step S4 A correction process is performed, and the process ends.

  In the present embodiment, a plurality of markers ki are formed using a plurality of pointers qi. However, when the marker size is large, one marker is formed using one pointer. And an attachment angle calculation process can be performed based on the image of this marker.

  In the present embodiment, the mounting angle is automatically corrected by the correction processing means, but can be manually corrected.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is a figure which shows the navigation system in embodiment of this invention. It is a figure which shows operation | movement of the calibration apparatus in embodiment of this invention. It is a perspective view of the back camera in an embodiment of the invention. It is a figure which shows the imaging | photography state of the marker by the back camera in embodiment of this invention. It is a 1st figure which shows the correction method of the attachment angle in embodiment of this invention. It is a 2nd figure which shows the correction method of the attachment angle in embodiment of this invention.

Explanation of symbols

31 CPU
49 Back camera k1 to k4 Marker q1 to q4 Pointer

Claims (5)

  A vehicle-mounted camera, a light-emitting device that is attached to the vehicle-mounted camera and irradiates the ground to form a marker on the ground, marker imaging processing means that images the marker with the vehicle-mounted camera, and recognizes the marker from the image of the marker A calibration apparatus comprising: an image recognition processing means; and an attachment angle calculation processing means for calculating an attachment angle of the camera based on the recognized marker.   The calibration apparatus according to claim 1, further comprising a correction processing unit that corrects the mounting angle of the in-vehicle camera based on the calculated mounting angle.   The calibration device according to claim 1, wherein a plurality of the light emitting devices are attached to the in-vehicle camera.   The calibration apparatus according to claim 1, wherein the attachment angle calculation processing unit calculates an attachment angle based on a size and shape of the marker. The light emitting device attached to the in-vehicle camera irradiates the ground, forms a marker on the ground, images the marker with the in-vehicle camera, recognizes the marker from the image of the marker, and based on the recognized marker, A calibration method characterized by calculating an attachment angle.

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