JP2007145251A - Driving support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving support device capable of performing an accurate driving assist to a control object in various situations by calculating, based on the detection of a road sign formed on a road surface, a road distance to the control object associated with the detected road sign. <P>SOLUTION: In this device, when it is determined that a road sign is presented within a predetermined range from a vehicle 2 (S2: YES), the road sign is recognized from an image taken by a rear camera 3 (S3), and a road distance from the vehicle 2 to a control object relevant with the recognized road sign is calculated (S5-S7). When it is determined that the road distance to the control object reaches a predetermined distance (S8: YES), the guide of traveling or the control of the vehicle according to the kind of the relevant control object is performed (S11). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving support device that assists a user in driving based on an image captured by an imaging unit, and more particularly, to a detected road marking based on detecting a road marking formed on the road surface. The present invention relates to a driving support apparatus that can assist driving accurately with respect to a controlled object under various circumstances by indirectly calculating a road distance to the associated controlled object.

Conventionally, road information obtained from the map data of the navigation device and various information related to vehicle travel, such as the current position specified by GPS, etc., are acquired, and notification to the driver, driving assistance, and further driving A driving support device that prevents vehicle accidents by intervening in the vehicle has been proposed.
And in such a driving support device, in order to perform necessary notification and control of the vehicle at a more accurate timing, an imaging means such as a camera is provided on the entire surface of the vehicle, and notification is made based on the captured image. And some that control the vehicle. For example, in Japanese Patent Laid-Open No. 2004-86363, a temporary stop line formed on a road on which the host vehicle travels is detected from image data captured by a CCD camera installed toward the front of the vehicle, and the detection result The vehicle driving assistance device that performs driving assistance at an intersection based on the above is described.
JP 2004-86363 A (pages 8 to 10, FIG. 4)

  However, in the vehicle driving assistance device described in Patent Document 1 described above, a temporary stop line to be controlled is directly detected by detection means such as a CCD camera, and guidance and vehicle control are performed for the detected control object. However, these devices have the following problems when put to practical use.

First, in order to perform guidance for the control target and control of the vehicle, it is necessary to detect the control target at a certain distance from the control target to the vehicle. Therefore, the remote control target is clearly imaged. An expensive system such as a high-performance camera was required. Even if a high-performance camera is used, there is a limit to the distance at which a control target can be detected, and results have been inadequate to perform necessary guidance and vehicle control. Furthermore, when the control target cannot be detected for some reason, the necessary guidance or vehicle control for the control target cannot be performed.
In addition, when a control target (for example, a temporary stop line) having a line segment in a direction perpendicular to the traveling direction of the vehicle is to be captured by a camera provided in the traveling vehicle, the control target in the captured image is blurred. There was a possibility that it could not be recognized correctly.

  On the other hand, in recent years, a vehicle equipped with a parking assistance device that displays a camera image obtained by capturing the rear environment of the vehicle during parking and assists the driver's parking operation with respect to the vehicle has appeared. In such a parking assistance device, the situation of the backward direction side with respect to the vehicle is displayed as an image to assist the driver's parking operation with respect to the vehicle, or the vehicle travels based on the signal from the steering angle sensor. There is known one that supports a driver's parking operation with respect to a vehicle by calculating a prediction curve and displaying the calculated progress prediction curve superimposed on the captured camera image as described above. However, these devices are used only during parking, and are not particularly used during normal driving. Therefore, there has been a demand for a new application in which the camera for imaging the rear environment during parking is used during normal driving.

  The present invention has been made to solve the above-described conventional problems, and indirectly calculates the road distance to the control object based on detecting the road marking formed on the road surface. An object of the present invention is to provide a driving support device capable of assisting driving with respect to an accurate control object under various circumstances.

In order to achieve the above object, a driving support device according to claim 1 of the present application is disposed in a vehicle, and an imaging unit that captures an image of the periphery of the vehicle, and a driving that assists a user's driving based on an image captured by the imaging unit. In the driving support device having the auxiliary means, formed on the road surface on which the vehicle travels based on the sign information storage means storing the position information of the road sign formed on the road surface and the image taken by the imaging means. The road marking detection means for detecting the road marking, the road marking detected by the road marking detection means, and the positional information stored in the marking information storage means, and associated with the road marking detected from the vehicle Object distance calculation means for calculating a road distance to the controlled object, wherein the driving assistance means is based on the calculation result of the object distance calculation means. And having to assist the operation of the user.
Here, “road marking” means a certain stylized line using paints, road fences or the like for necessary guidance, guidance, caution, regulations, instructions, etc. for road traffic. In addition, it means a character or symbol placed on the road surface, for example, a stop line or a pedestrian crossing.
In addition, the “control object” refers to an object on the road on which driving assistance (for example, guidance on the control object, control of the vehicle, etc.) is to be performed. There are intersections and entrances to curves.

  A driving support device according to a second aspect of the present invention is the driving support device according to the first aspect, further comprising drive control means for controlling driving of the vehicle, wherein the driving assistance means is provided from the vehicle to the control object. Control of driving by the vehicle drive control means is performed based on a road distance.

  According to a third aspect of the present invention, there is provided a driving assistance device according to the first aspect, further comprising traveling guidance means for performing guidance related to traveling to a user, wherein the driving assistance means includes the vehicle to be controlled. Guidance by the travel guidance means is performed based on a road distance to an object.

  Furthermore, the driving support apparatus according to claim 4 is the driving support apparatus according to any one of claims 1 to 3, wherein a current position detection means for detecting a current position of the vehicle, a detection result of the current position detection means, and the Road marking presence determining means for determining whether or not there is a road marking within a predetermined range from the current location of the vehicle based on position information stored in the marking information storage means, and the road marking detection means Is characterized in that the road marking is detected when it is determined by the road marking presence determination means that the road marking is present.

In the driving support device according to claim 1 having the above-described configuration, by detecting a road marking formed on a road surface on which the vehicle travels, and calculating a road distance to a control object associated with the detected road marking. Because it assists the operation of the control object, there is no need to detect the control object such as a stop line or an intersection directly, based on the detection result of the road marking at an early stage when the distance from the control object is far away. Indirectly, it is possible to accurately calculate the road distance from the vehicle to the controlled object. Therefore, it is possible to reliably control the control object without requiring an expensive device such as an image pickup device using a front camera in order to take an image of a distant place.
Further, in the case where the control object is directly detected as in the prior art, guidance and control for the control object cannot be performed when the target control object cannot be recognized, but it is based on the road marking. Even if one road marking cannot be detected by indirectly detecting the control target, the control target is detected by detecting another road marking associated with the same control target. It is possible to perform guidance and control for the.
In addition, since it is possible to specify the exact position of the vehicle, it is possible to guide the route at a more accurate timing in the guidance at a location that requires a guidance route such as an intersection.
Furthermore, even if the control object has a line segment in a direction perpendicular to the traveling direction of the vehicle (for example, a stop line), it is not necessary to directly image the control object. There is no possibility that the control object cannot be correctly recognized due to the blurring of the image caused by imaging.

  In the driving support device according to the second aspect of the invention, since the driving of the vehicle is controlled based on the road distance from the vehicle to the controlled object, an expensive device such as an imaging device using a front camera is used to take an image of a distant place. It is possible to reliably control the vehicle according to the type of the control object without requiring it.

  In the driving support device according to the third aspect of the present invention, guidance on traveling is performed on the basis of the road distance from the vehicle to the controlled object, so that an expensive device such as an imaging device using a front camera is required to image a distant place. Therefore, it is possible to reliably guide traveling according to the type of the control object.

  Further, in the driving support device according to claim 4, since the road marking is detected when the road marking exists within a predetermined range from the current position of the vehicle, the detection processing using the imaging means is performed only at a necessary timing, and the road surface It is possible to minimize the processing load on the apparatus in detecting the sign. Accordingly, an inexpensive system can be configured without requiring a separate image processing control unit.

  Hereinafter, the driving support device according to the present invention will be described in detail with reference to the drawings based on the first and second embodiments embodied.

(First embodiment)
First, a schematic configuration of the driving support device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a driving support apparatus 1 according to the first embodiment.
As shown in FIG. 1, the driving support device 1 according to the first embodiment includes a rear camera (imaging means) 3, a navigation device 4, a vehicle ECU 5, and the like installed on a vehicle 2.

  The rear camera 3 uses a solid-state image sensor such as a CCD, for example, and is installed near the upper center of the license plate mounted on the rear side of the vehicle 2 and installed with the line of sight 45 degrees below the horizontal. The Then, the rear side of the vehicle in the traveling direction of the vehicle 2 is imaged when parked, and the captured image (hereinafter referred to as a BGM (back guide monitor) image) is displayed on the liquid crystal display 7 of the navigation device. On the other hand, during normal traveling, road markings such as a stop line, a pedestrian crossing, and the maximum speed of the vehicle formed on the road surface around the vehicle 2 are imaged as described later. Then, the distance from the vehicle 2 to a control object that is a target for performing vehicle guidance and control of the vehicle such as a stop line, an intersection, a curve entrance, and the like is indirectly calculated based on the captured road marking image.

The navigation device 4 includes a navigation ECU (Electronic Control Unit) 6 and a liquid crystal display (running guide means) that is provided on the center console or panel surface of the vehicle 2 and displays a map and a search route to the destination. ) 7, a speaker (running guidance means) 8 for outputting voice guidance related to route guidance, a current location detection unit (current location detection means) 9 for specifying the current location and traveling direction of the vehicle 2 on the map, and for displaying a map The data recording unit 10 stores information related to the map data and the types and positions of road markings formed on the road surface, and the communication device 13 for communicating with an information center or the like.
The navigation ECU (driving assistance means, road marking means, object distance calculation means, road marking presence determination means) 6 is a vehicle 2 based on a captured image captured by the rear camera 3 in addition to normal route search and route guidance processing. Detection processing for detecting road markings formed on the road surface on which the vehicle travels, calculation for indirectly calculating the road distance from the vehicle 2 to a controlled object such as a stop line, an intersection, or a curve entrance from the detected road marking This is an electronic control unit that performs an instruction for drive control of the vehicle 2 and a route guidance process based on the processing and the calculated distance. The detailed configuration of the navigation ECU 6 will be described later.

  The vehicle ECU 5 is an electronic control unit of the vehicle 2 that controls the operation of the engine, transmission, accelerator, brake, and the like. A brake actuator (drive control means) 11 and an accelerator actuator (drive control means) 12 are connected to the vehicle ECU 5. Yes. The navigation ECU 6 transmits a control signal to the brake actuator 11 and the accelerator actuator 12 via the vehicle ECU 5 when a predetermined condition is satisfied, changes the brake pressure and the amount of air taken into the engine, and automatically increases the braking force. To give.

Next, the configuration related to the control system of the driving support device 1 according to the first embodiment will be described with reference to FIG. FIG. 2 is a block diagram schematically showing a control system of the driving support device 1 according to the first embodiment.
In FIG. 2, the control system of the driving support device 1 is configured based on the navigation device 4 and the vehicle ECU 5, and predetermined peripheral devices are connected to each control means.

  Hereinafter, each component constituting the navigation device 4 will be described. The current location detection unit 9 includes a GPS 31, a geomagnetic sensor 32, a gyro sensor 33, a steering sensor 34, a distance sensor 35, an altimeter (not shown), and the like. It is possible to detect the current position, direction, travel distance from a predetermined point, and the like.

  Specifically, the GPS 31 detects the current location and current time of the vehicle on the earth by receiving radio waves generated by artificial satellites, and the geomagnetic sensor 32 measures the direction of the vehicle by measuring the geomagnetism. Is detected.

  And the gyro sensor 33 detects the turning angle of the own vehicle. Here, as the gyro sensor 33, for example, a gas rate gyro, a vibration gyro, or the like is used. Further, by integrating the turning angle detected by the gyro sensor 33, the vehicle direction can be detected.

  The steering sensor 34 detects the rudder angle of the host vehicle. Here, as the steering sensor 34, for example, an optical rotation sensor attached to a rotating portion of a steering wheel (not shown), a rotation resistance sensor, an angle sensor attached to a wheel, or the like is used.

  Further, the distance sensor 35 detects a moving speed (integrated moving distance) based on a vehicle speed pulse generated at every constant travel distance from the engine.

  Further, the data recording unit 10 stores an external storage device and a hard disk (not shown) as a recording medium, a predetermined program recorded on the hard disk, route guidance such as map data, and information necessary for map display. A map DB 41, a road marking DB (marking information storage means) 42 in which information related to road markings is stored, and the like are provided, and a recording head (not shown) which is a driver for writing predetermined data to the hard disk is provided. In the first embodiment, a hard disk is used as the external storage device and storage medium of the data recording unit 10, but in addition to the hard disk, a magnetic disk such as a flexible disk can be used as the external storage device. Also, a memory card, magnetic tape, magnetic drum, CD, MD, DVD, optical disk, MO, IC card, optical card, etc. can be used as an external storage device.

  The map DB 41 stores various information necessary for route guidance and map display. For example, map data for displaying a map, intersection data for each intersection, node data for node points, and road information. Road data, search data for searching for a route, facility data related to a facility, search data for searching for a point, and the like are recorded. Furthermore, in the navigation apparatus 4 according to the first embodiment, the type of road marking formed on the road surface with respect to the road marking DB 42 (for example, stop line, pedestrian crossing, maximum speed) and the type of detected road marking are shown. Specific information for specifying and coordinate data for specifying the position of the road marking on the map are also recorded. The road marking DB 42 will be described in detail later with reference to FIG.

  The navigation ECU 6 is used as a working memory when the CPU performs various arithmetic processes, in addition to the arithmetic device that controls the entire navigation device 4 and the CPU as the control device, and when a route is searched for. In addition to RAM, which stores route data, and control programs, a route guidance processing program that searches for a route to the destination, guides the searched guidance route, and an image captured by the rear camera 3 It includes an internal storage device such as a ROM in which a driving support processing program (see FIG. 9) described later for calculating driving distances to objects (stop lines, intersections, curve entrances, etc.) and driving assistance is recorded. Yes. As the RAM, ROM, etc., a semiconductor memory, a magnetic core, etc. are used. As the arithmetic device and the control device, an MPU or the like can be used instead of the CPU.

  The navigation ECU 6 includes a GUI control unit 51, a location unit 52, and a route search / guidance processing unit 53. Based on information acquired from the rear camera 3, the current location detection unit 9, the data recording unit 10, and each peripheral device. Various controls are performed.

Here, the GUI control unit 51 displays an appropriate map image around the vehicle on the liquid crystal display 7 based on the map data read from the map DB 41 and the current position of the vehicle detected by the location unit 52. When route guidance is required, an icon, a guidance screen, a search route, and the like are combined with the map image and displayed on the liquid crystal display 7.
The location unit 52 detects the current absolute position (latitude / longitude) of the vehicle 2 based on each information supplied from the current location detection unit 9. Further, it is determined whether or not a road marking exists within a predetermined range (30 m forward to 20 m backward) of the vehicle 2 from the detected current position and information stored in the road marking DB 42. The image picked up by 3 is taken and analyzed, and a road marking on the road surface is detected. Further, the distance between the road marking detected from the captured image and the vehicle 2 is calculated, and further the distance to the control object associated with the road marking is calculated from the distance, and the brake actuator 11 according to the calculated distance, The accelerator actuator 12 is controlled to control the driving of the vehicle 2, or traveling is guided by the liquid crystal display 7 and the speaker 8.
Further, the route search / guidance processing unit 53 performs a route search from the current location to the destination based on the node point data and the search data stored in the data recording unit 10 when the destination is set, and is set. The route guidance is performed using the liquid crystal display 7 and the speaker 8 according to the guidance route.

  The navigation ECU 6 is electrically connected to peripheral devices such as a liquid crystal display 7, a speaker 8, and a communication device 13.

  The liquid crystal display 7 has operation guidance, operation menu, key guidance, guidance route from the current location to the destination, guidance information along the guidance route, traffic information, news, weather forecast, time, mail, TV program, rear camera The BGM image captured in step 3 is displayed. Instead of the liquid crystal display 7, it is also possible to use a CRT display, a plasma display, or the like, or a hologram device that projects a hologram onto the windshield of a vehicle.

  Further, the speaker 8 outputs voice guidance for guiding traveling along the guidance route based on an instruction from the navigation ECU 6. Here, examples of the voice guidance to be guided include “Please turn right at the intersection 200 meters ahead” and “The next national highway No. XX is congested”. In addition to the synthesized voice, the voice output from the speaker 8 can output various sound effects and various guidance information recorded in advance on a tape, a memory, or the like. Furthermore, in the navigation device 4 according to the first embodiment, when the distance from the own vehicle to the control object becomes a predetermined distance, the travel guidance related to the control object (for example, the stop line) is displayed by the liquid crystal display 7 and the speaker 8. Warning of approaching).

  Then, the communication device 13 is used for information such as traffic congestion information, regulation information, parking lot information, traffic accident information, service area congestion, etc. transmitted from an information center, for example, a VICS (registered trademark: Vehicle Information and Communication System) center. It is a beacon receiver that receives traffic information composed of each information as a radio beacon, an optical beacon, or the like via a radio beacon device, an optical beacon device, or the like arranged along a road. The communication device 13 is a network that enables communication in a communication system such as a LAN, WAN, intranet, cellular phone network, telephone network, public communication network, dedicated communication network, or communication network such as the Internet. It may be a device. Further, the communication device 13 includes an FM receiver that receives FM multiplex information including information such as news and weather forecast as FM multiplex broadcast via the FM broadcast station in addition to the information from the information center. The beacon receiver and the FM receiver are unitized and arranged as a VICS receiver, but can be arranged separately. Moreover, the navigation apparatus 4 which concerns on 1st Embodiment connects to an information center via the communication apparatus 13, and updates the information stored in map DB41 and road marking DB42.

  Next, the road marking DB 42 in which information related to road marking is stored in the data recording unit 10 will be described with reference to FIG. FIG. 3 is a diagram showing a storage area of the road marking DB 42 according to the first embodiment.

As shown in FIG. 3, the storage area of the road marking DB 42 includes coordinates (positions) on the road marking map data, the type of road marking, a control object associated with the road marking, and a measurement start point of the road marking. It consists of the road distance from the control object (when there are a plurality of measurement start points closest to the control object). For example, in FIG. 3, a road marking “with a pedestrian crossing” is formed at coordinates (x1, y1), and the road marking is associated with a road marking “stop line” as a control object 60 m ahead. It is shown that In addition, a road marking of “arrow” is formed at the coordinates (x2, y2), and “intersection (node of intersection)” is associated with the road marking as a control object 54 m ahead. Indicates. In addition, a road marking of “maximum speed” is formed at the coordinates (x3, y3), and “corner (node of corner start point)” is associated with the road marking as a control object 72 m ahead. Indicates that In addition, a road marking of “pedestrian crossing” is formed at the coordinates (x4, y4), and “crossing (node of intersection)” is associated with the road marking as a control object 89 m ahead. It shows that.
In addition, regarding the road distance to the control object, when the road includes a plurality of lanes, the road distance to the control object for each lane is recorded.

  Here, the control object is a target for driving guidance and vehicle control, and is a traveling direction of the road on which the road marking is formed, and is a node point in a predetermined section (for example, 10 m to 200 m) Other road markings are used. Then, when the rear camera 3 images one of the road markings recorded in the road marking DB 42, the navigation ECU 6 indirectly calculates the road distance to the associated control object from the captured image. When the road distance reaches a predetermined distance, drive control of the vehicle 2 and travel guidance are performed.

  In addition, the content of the drive control of the vehicle 2 and the guidance of traveling differ depending on the type of the control object associated, for example, when “stop line” is associated as the control object, the road to the stop line When the distance becomes 50 m, the character string “Stop line is approaching” indicating that the stop line is approaching is displayed on the liquid crystal display 7, and the warning sound of the same content is displayed from the speaker 8. Is output. Further, when deceleration is not performed at that time, the brake actuator 11 is controlled to perform deceleration control so that the vehicle 2 stops before the stop line.

  Further, when “intersection” is associated as the control object, route guidance is performed according to the guidance route set when the road distance to the node of the corresponding intersection becomes 10 m. For example, a guidance display indicating a left turn is displayed on the liquid crystal display 7, and a guidance voice “Please turn left at the next intersection” is output from the speaker 8. In the case where no guidance route is set, no guidance display or guidance voice is output.

  In addition, when “corner” is associated as the control object, the corner of the corner recorded in the map DB 41 before entering the corner at the time when the road distance to the node of the corresponding corner start point becomes 50 m. The brake actuator 11 and the accelerator actuator 12 are controlled so as to achieve an optimum speed for R (for example, 40 km / h at R30), and acceleration / deceleration control is performed. Further, during cornering, the brake actuator 11 and the accelerator actuator 12 are similarly controlled so as to achieve an optimum speed, thereby performing acceleration and deceleration control.

Next, the distance between the vehicle 2 and the road marking when the road marking is imaged by the rear camera 3 of the vehicle 2 with reference to FIGS. 4 to 8, and the distance between the vehicle 2 and the control object associated with the road marking. The calculation method will be described with a specific example.
In the following specific example, among the road markings formed on the road surface 60 on which the vehicle 2 travels, a road marking 61 “with a pedestrian crossing” associated with a road marking 69 of a stop line as an object to be controlled is imaged. Let's show the case. 4 is a top view showing the vehicle 2 that images the road marking 61, FIG. 5 is a side view that shows the vehicle 2 that images the road marking 61, and FIG. 6 is a rear camera of the vehicle 2 in the state of FIGS. 3 is a schematic diagram illustrating a captured image 62 captured by 3.

  As shown in FIG. 5, the rear camera 3 is mounted so that the optical axis L is directed 45 degrees downward from the horizontal so that the rear can be imaged from the vicinity of the rear bumper 63 of the vehicle 2, and the imaging range is fixed. Yes. Therefore, the distance to the subject can be calculated from the position of the image data (specifically, the number of pixels from the lower edge) in the captured image shown in FIG. 6 captured by the rear camera 3.

Here, a plurality of measurement start points for measuring the distance to the vehicle 2 are defined in advance in the road marking, and the distance from the vehicle 2 to the measurement start point closest to the traveling direction is determined from the vehicle 2 to the road surface. Treat as the distance to the marking. For example, FIG. 7A is a schematic diagram showing measurement start points 61A to 61D of the road marking 61 “with crosswalk”, and FIG. 7B is a road marking 65 of “maximum speed (20 km / h)”. It is the schematic diagram which showed the measurement start points 65A-65D.
As shown in FIG. 7 (A) and FIG. 7 (B), a plurality of road marking start points are provided at the corners and tips of lines (boundary lines) that form road markings. Has a unique arrangement. And when navigation ECU6 images a road marking, it becomes possible to determine the kind of road marking by specifying the boundary line and measurement start point of the road marking from the image of the imaged road marking.

  Further, in the captured image obtained by imaging the road marking shown in FIG. 6, the distance D1 between the vehicle 2 and the measurement start point from the position of the measurement start point (specifically, the number of pixels from the lower edge to the measurement start point). It is possible to calculate. Here, of the plurality of measurement start points, the distance to which the measurement start point is calculated is determined for each road marking, for example, “with crosswalk” shown in FIG. In the road marking 61, the distance from the measurement start point 61A is calculated. However, the measurement start point 61A is due to some cause (for example, when a part of the white line is hidden by an obstacle such as sand or a puddle, or when the paint is peeled off by a part of the white line due to deterioration over the years) If the distance cannot be specified, the distance to the measurement start point 61B is calculated first, and then the distance between the measurement start point 61A and the measurement start point 61B is used to indirectly calculate the distance to the measurement start point 61A. Is done. Furthermore, when the measurement start point 61B cannot be specified, the measurement start point 61C is used, and when the measurement start point 61C cannot be specified, the measurement start point 61D is used.

  Further, in the road marking 65 of “maximum speed (20 km / h)” shown in FIG. 7B, the distance between the measurement start point 65A and the measurement start point 65B is calculated. However, the measurement start point 65A and the measurement start point 65B are for some reason (for example, a part of the white line is hidden by an obstacle such as sand or a puddle, or a part of the white line is peeled off due to deterioration over the years. If the measurement start point 65C and the measurement start point 65D are used, the distance between the measurement start point 65A and the measurement start point 65B is indirectly calculated.

  On the other hand, when the distance D1 between the vehicle 2 and the measurement start point of the road marking is calculated by the method described above, the control object (see FIG. 3) associated with the road marking detected from the vehicle 2 based on the distance D1 is calculated. It is possible to calculate the road distance. FIG. 8 is a schematic diagram illustrating a method of calculating a road distance from the vehicle 2 to the control object when a road marking is imaged by the rear camera 3 of the vehicle 2.

FIG. 8 shows the case where the vehicle 2 detects the road marking 61 “with a pedestrian crossing” with the rear camera 3. Further, the road marking 61 has a road distance D2 ahead as a control object. A road marking 69 of “stop line” is associated.
In that case, by subtracting the distance D1 from the distance D2, it becomes possible to calculate the road distance (D2-D1) from the vehicle 2 to the controlled object at the time when the road marking 61 is detected. Further, the navigation ECU 6 calculates the travel distance S of the vehicle 2 by the distance sensor 35 based on the vehicle speed pulse generated at every constant travel distance from the engine. Then, by subtracting the travel distance S from the distance from the vehicle 2 to the controlled object (D2-D1), the road distance (D2-D1-S) from the traveling vehicle 2 to the controlled object is calculated. It becomes possible. Further, the vehicle 2 is stopped along the stop line by controlling the brake actuator 11 based on the calculated distance (D2-D1-S) from the “stop line” to the road marking 69. The brake pressure can be adjusted.

In FIG. 9, as another specific example, the vehicle 2 travels on a road composed of three lanes, and the road distance to the corner start point 72 that is the control target is calculated based on the detection of the road surface display 71. The case where it does is shown. Here, in a road composed of a plurality of lanes, a control object for the road marking 61 (a corner start point 72 in FIG. 9) is a road distance D2 along the curve for each lane (the outer lane has a longer distance D2). ) Is associated.
Then, as shown in FIG. 9, when the vehicle 2 detects the road marking 71 “with a pedestrian crossing” with the rear camera 3, the distance D1 is subtracted from the distance D2 to detect the road marking 71. It is possible to calculate the road distance (D2-D1) along the curve from the vehicle 2 to the controlled object. Further, the navigation ECU 6 calculates the travel distance S of the vehicle 2 by the distance sensor 35 based on the vehicle speed pulse generated at every constant travel distance from the engine. Then, by subtracting the travel distance S from the distance from the vehicle 2 to the control object (D2-D1), the road distance (D2-D1-S) along the curve from the traveling vehicle 2 to the control object. ) Can be calculated.

Further, in FIG. 10, as another specific example, the vehicle 2 travels on a road constituted by an uphill and, based on the detection of the road surface display 73, up to the road marking 74 of the “stop line” that is the control object. The case of calculating the road distance will be described. Here, the road marking 73 is associated with a “stop line” road marking 74 at a road distance D2 along the slope of the slope as a control object.
Then, as shown in FIG. 10, when the vehicle 2 detects the road marking 73 “with a pedestrian crossing” with the rear camera 3, the distance D1 is subtracted from the distance D2 to detect the road marking 73. It is possible to calculate the road distance (D2-D1) along the slope of the slope from the vehicle 2 to the controlled object. Further, the navigation ECU 6 calculates the travel distance S of the vehicle 2 by the distance sensor 35 based on the vehicle speed pulse generated at every constant travel distance from the engine. Then, by subtracting the travel distance S from the distance (D2-D1) from the vehicle 2 to the controlled object, a road distance (D2-D1) along the slope of the slope from the traveling vehicle 2 to the controlled object. -S) can be calculated.

  As described above, by directly calculating the road distance from the road marking detected by the rear camera 3 to the control object in front without directly recognizing the control object, it can be accurately performed at an earlier stage. It becomes possible to calculate the road distance (D2-D1-S) to the control object. Then, based on the calculated road distance (D2-D1-S) to the accurate control object, appropriate vehicle control and travel guidance at a more accurate timing can be performed.

  Next, a driving assistance processing program executed by the navigation ECU 6 of the driving assistance apparatus 1 according to the first embodiment having the above configuration will be described with reference to FIG. FIG. 11 is a flowchart of the driving support processing program in the driving support device 1 according to the first embodiment. Here, the driving support processing program detects the road marking from the captured image captured by the rear camera 3 when the vehicle 2 travels on the road surface, and calculates the road distance from the detected road marking to the vehicle and the control object. It detects and performs control which assists a user's driving | operation based on the distance. Note that the program shown in the flowchart in FIG. 11 is stored in a ROM or RAM provided in the navigation ECU 6 and is executed by the CPU.

  In the driving support process, first in step (hereinafter abbreviated as S) 1, the navigation ECU 6 detects the current location information of the vehicle 2 detected by the current location detection unit 9 and the position of the road marking recorded in the road marking DB 42 (see FIG. 3). Based on the information, information on road markings located around the vehicle 2 (2000 m forward to 500 m behind the vehicle 2 in the first embodiment) is read from the road marking DB 42.

  Next, in S2, it is determined whether or not there is a road marking located in a predetermined range (30m forward to 20m forward of the vehicle 2) of the road marking read out in S1. If it is determined that there is a road marking located in a predetermined range of the vehicle 2 (S2: YES), the process proceeds to S3, and image recognition processing of the road marking is performed. On the other hand, when it is determined that there is no road marking located in the predetermined range of the vehicle 2 (S2: NO), the process returns to S1 and the road marking information based on the current location is read again. This S2 corresponds to the process of the road marking presence determination means.

In the image recognition processing of the road marking in S3, the image of the rear environment of the vehicle 2 captured by the rear camera 3 is captured and analyzed, and the boundary line of the road marking formed on the road surface on which the vehicle travels and measurement start While specifying a point, the kind of detected road marking is determined.
Specifically, first, an image captured by the rear camera 3 is input using analog communication means such as NTSC or digital communication means such as i-link, and is converted into a digital image format such as jpeg or mpeg. . Next, using the fact that the road marking is generally a white line or a yellow line, luminance correction is performed on the road surface on which the road marking in the captured image is drawn and another road surface based on the luminance difference. After that, binarization processing to separate the target road marking from the image, geometric processing to correct distortion, smoothing processing to remove noise in the image, etc., boundary line between road marking and other road surface and measurement Detect the starting point.
Thereafter, the type of the road marking detected from the detected boundary line and the arrangement of the measurement start point is specified, and further, the road surface determined that the specified road marking type is present in the predetermined range of the host vehicle in S2. It is determined whether or not it matches the type of marking. This S3 corresponds to the process of the road marking detection means.

  In S4, it is determined whether or not the road marking has been recognized. If it is determined that the road marking has been recognized (S4: YES), that is, the road marking is detected in the captured image and is detected. If it is determined that the determined road marking matches the type of road marking determined to be located around the vehicle in S2, the process proceeds to S5. On the other hand, when it is determined that the road marking has not been recognized (S4: NO), that is, the road marking has not been detected in the captured image, or the detected road marking has been detected in S2 If it is determined that the type of the road marking determined to be located in the vicinity does not match, the process returns to S1 and the road marking information based on the current location is read again.

  In S5, the distance between the road marking detected in S3 and the vehicle 2 is calculated. Specifically, the vehicle 2 and the measurement start are determined from the position of the specified measurement start point (specifically, the number of pixels from the lower edge to the measurement start point) in the captured image obtained by capturing the road marking (see FIG. 6). A distance D1 between the points is calculated.

  Thereafter, in S6, the distance D1 between the vehicle 2 and the measurement start point calculated in S5 and the road distance D2 to the control object associated with the detected road marking (the value of D2 is the road marking DB 42 in advance). The road distance (D2-D1) from the vehicle 2 to the control object associated with the road marking detected from the vehicle 2 is calculated (see FIG. 8).

  Further, in S7, the distance sensor 35 calculates the travel distance S of the vehicle 2 from the detection point of the road marking based on the vehicle speed pulse generated every constant travel distance from the engine, and the vehicle 2 calculated in S6 is controlled. Based on the road distance to the object (D2-D1), the remaining road distance (D2-D1-S) from the traveling vehicle 2 to the control object is calculated (see FIG. 8). Note that S5 to S7 correspond to the processing of the object distance calculation means.

  In S8, based on the remaining distance (D2-D1-S) along the road to the control object calculated in S7, the vehicle 2 is set to a guidance or control start point set for each type of control object. It is determined whether or not it has been reached. For example, when the control target is a “stop line” road marking, it is determined that the guidance or control start point has been reached when the remaining distance is within 50 m. Further, when the control target is a road marking of “intersection”, it is determined that the guidance or control start point has been reached when the remaining distance is 10 m. Further, when the control target is a “corner” road marking, it is determined that the guidance or control start point has been reached when the remaining distance is within 50 m.

If it is determined that the vehicle 2 has reached the guidance or control start point (S8: YES), it is determined whether the travel guidance for the controlled object or the drive control of the vehicle 2 is necessary. Or based on the presence or absence of a destination setting (S9). Here, in the driving support device 1 according to the first embodiment, when the “stop line” is associated as the control target, the stop line is displayed when the distance from the stop line becomes 50 m. A character string “stop line is approaching” indicating that the vehicle is approaching is displayed on the liquid crystal display 7, and a warning sound having the same content is output from the speaker 8. Further, when deceleration is not performed at that time, the brake actuator 11 is controlled to perform deceleration control so that the vehicle 2 stops before the stop line.
Further, when “intersection” is associated as the control object, route guidance is performed according to the guidance route set when the road distance to the node of the corresponding intersection becomes 10 m. For example, a guidance display indicating a left turn is displayed on the liquid crystal display 7, and a guidance voice “Please turn left at the next intersection” is output from the speaker 8.
In addition, when “corner” is associated as the control object, the corner of the corner recorded in the map DB 41 before entering the corner at the time when the road distance to the node of the corresponding corner start point becomes 50 m. The brake actuator 11 and the accelerator actuator 12 are controlled so as to achieve an optimum speed for R (for example, 40 km / h at R30), and acceleration / deceleration control is performed.

  Therefore, for example, even when “corner” is associated as a control object, it is necessary to control the brake actuator 11 and the accelerator actuator 12 when the vehicle 2 is already traveling at an optimum speed. Judge that there is no. Further, even when “intersection” is associated as a control object, it is not necessary to perform travel guidance when a guidance route is not set (when a destination is not set). Is determined.

  If it is determined in S10 that traveling guidance for the control object or drive control of the vehicle 2 is necessary (S10: YES), traveling guidance or vehicle 2 according to the type of the control object in S11. The drive control process is performed. The specific contents of the guidance process and the drive control process are as described above.

  On the other hand, when it is determined that the vehicle 2 has not reached the guidance or control start point (S8: NO), and when it is determined that traveling guidance for the controlled object or drive control of the vehicle 2 is not necessary (S10). : NO), the process returns to S7, and the remaining distance (D2-D1-S) from the current vehicle 2 to the control object is calculated again.

  Subsequently, in S12, whether or not the remaining distance (D2-D1-S) to the control object calculated in S7 has become 0, that is, whether or not the vehicle 2 has reached the position of the control object. Is determined. When it is determined that the position of the control target has been reached (S12: YES), the driving support process ends. On the other hand, if it is determined that the position of the control object has not been reached (S12: NO), the process returns to S7 and the remaining distance from the current vehicle 2 to the position of the control object (D2-D1- S) is calculated again.

As described above in detail, in the driving support device 1 according to the first embodiment, when it is determined that a road marking exists within a predetermined range from the vehicle 2 (S2: YES), an image captured by the rear camera 3 (S3), the road distance to the control object associated with the road surface recognized from the vehicle 2 is calculated (S5 to S7), and the road distance to the control object is predetermined. When it is determined that the distance has been reached (S8: YES), the vehicle guides or controls the vehicle according to the type of the associated control object (S11), so the control object such as a stop line or intersection is directly controlled. There is no need to detect objects, and it is possible to accurately calculate the road distance from the vehicle to the control object indirectly based on the detection result of the road marking at an early stage when the distance from the control object is far away. It becomes. Therefore, it is possible to reliably control the control object without requiring an expensive device such as an image pickup device using a front camera in order to take an image of a distant place. Further, in the case where the control object is directly detected as in the prior art, guidance and control for the control object cannot be performed when the target control object cannot be recognized, but it is based on the road marking. Even if one road marking cannot be detected by indirectly detecting the control target, the control target is detected by detecting another road marking associated with the same control target. It is possible to perform guidance and control for the.
In addition, since it is possible to specify the exact position of the vehicle 2, it is possible to guide the route at a more accurate timing in the guidance at a location that requires a guidance route such as an intersection.
Further, only when it is determined that a road marking exists within a predetermined range from the vehicle 2, the road marking is recognized from the image captured by the rear camera 3, thereby minimizing the processing load on the navigation device 4. It becomes possible. Therefore, it is possible to perform processing in parallel with the processing of the navigation function that the original navigation device 4 has, and it can be configured by an inexpensive system without requiring a separate image processing control unit. It becomes possible.
Furthermore, even if the control object has a line segment in a direction perpendicular to the traveling direction of the vehicle (for example, a stop line), it is not necessary to directly image the control object. There is no possibility that the control object cannot be correctly recognized due to the blurring of the image caused by imaging.

(Second Embodiment)
Next, the driving assistance apparatus 100 according to the second embodiment will be described with reference to FIG. In the following description, the same reference numerals as those of the driving support apparatus 1 according to the first embodiment in FIGS. 1 to 11 are the same as or equivalent to those of the driving support apparatus 1 according to the first embodiment. It is shown.

The schematic configuration of the driving support apparatus 100 according to the second embodiment is substantially the same as that of the driving support apparatus 1 according to the first embodiment. Various control processes are also substantially the same as the driving support apparatus 1 according to the first embodiment.
However, the driving support device 1 according to the first embodiment includes a rear camera 3 that captures a rear environment as an imaging unit, recognizes a road marking based on an image captured by the rear camera, and controls the control object. On the other hand, in the driving support apparatus 100 according to the second embodiment, in addition to the rear camera 3, a front camera 101 that images the front environment of the vehicle 2 is provided as an imaging unit. 101 is different from the driving support apparatus 1 according to the first embodiment in that the road marking is recognized based on the image captured in 101 and the control target is controlled.

First, a schematic configuration of the driving support apparatus 100 according to the second embodiment will be described with reference to FIG. FIG. 12 is a schematic configuration diagram of the driving support apparatus 100 according to the second embodiment.
As shown in FIG. 12, the driving support device 1 according to the second embodiment includes a front camera 101, a rear camera 3, a navigation device 4, a vehicle ECU 5, and the like installed with respect to the vehicle 2.

  The front camera 101 uses a solid-state image sensor such as a CCD, for example, and is attached near the upper center of the license plate mounted in front of the vehicle 2 and is installed with the line-of-sight direction slightly below the horizontal. . Then, a traffic light, a road sign, a road marking, and the like installed in front of the vehicle 2 are imaged.

  The configurations of the rear camera 3, navigation device 4, and vehicle ECU 5 other than the front camera 101 are the same as those of the driving support device 1 according to the first embodiment described above, and a description thereof is omitted.

  And in the driving assistance apparatus 100 which concerns on 2nd Embodiment, based on the image imaged with the front camera 101, it becomes possible to implement | achieve the expansion of a control object and the improvement of the recognition rate of a road marking as follows.

  For example, when it is determined that the traffic light located at the front intersection is lit in red based on the image captured by the front camera 101, the travel guidance according to the control object of the “intersection” as described above In addition to the vehicle drive control (S8 to S11), a warning that the traffic light at the intersection is lit in red is given, and the brake actuator 11 is controlled so that the vehicle 2 stops before the intersection. It becomes possible.

  Further, when it is determined that a stop road sign is installed at an intersection ahead based on an image captured by the front camera 101, travel guidance according to the control object of the “intersection” as described above. In addition to the vehicle drive control (S8 to S11), it is possible to give a warning for a temporary stop and to control the brake actuator 11 so that the vehicle 2 stops before the intersection.

  In addition, when it is determined that a road marking is formed on the road surface ahead based on an image captured by the front camera 101, the timing at which the vehicle 2 passes the road marking is calculated, and the timing is calculated. By performing image recognition processing by the rear camera 3, it is possible to improve the recognition rate of road marking even when the rear camera 3 having a narrow field of view is used.

As described above in detail, in the driving assistance device 100 according to the second embodiment, when it is determined that a road marking is present within a predetermined range from the vehicle 2 (S2: YES), an image captured by the rear camera 3 (S3), the road distance to the control object associated with the road surface recognized from the vehicle 2 is calculated (S5 to S7), and the road distance to the control object is predetermined. When it is determined that the distance has been reached (S8: YES), the vehicle guides or controls the vehicle according to the type of the associated control object (S11), so the control object such as a stop line or intersection is directly controlled. There is no need to detect objects, and it is possible to accurately calculate the road distance from the vehicle to the control object indirectly based on the detection result of the road marking at an early stage when the distance from the control object is far away. And .
Further, based on the image analysis of the image of the environment in front of the vehicle 2 captured by the front camera 101, it is possible to perform more accurate travel guidance and vehicle drive control according to the current surrounding conditions of the vehicle 2. Further, by causing the front camera 101 to recognize the road marking in advance, it is possible to improve the recognition rate of the road marking even when the rear camera 3 with a narrow field of view is used.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the first embodiment and the second embodiment, the case where the control object is a stop line, an intersection, or a corner entrance has been described. However, the control object is not limited to the above, and for example, a pedestrian crossing In addition to road markings, it may be an interchange facility.

It is a schematic structure figure of a driving support device concerning a 1st embodiment. It is a block diagram showing typically the control system of the driving support device concerning a 1st embodiment. It is the figure which showed the memory area of road marking DB which concerns on 1st Embodiment. It is the top view which showed the vehicle which images a road marking. It is the side view which showed the vehicle which images a road marking. It is the schematic diagram which showed the captured image imaged with the back camera of the vehicle in the state of FIG.4 and FIG.5. (A) is a schematic diagram showing the measurement start point of the road marking “with pedestrian crossing”, and (B) is a schematic diagram showing the measurement start point of the road marking of “maximum speed (20 km / h)”. It is the schematic diagram shown about the calculation method of the road distance from a vehicle at the time of imaging a road marking with the back camera of a vehicle to a control target object. It is the schematic diagram shown about the calculation method of the road distance from a vehicle at the time of imaging a road marking with the back camera of a vehicle to a control target object. It is the schematic diagram shown about the calculation method of the road distance from a vehicle at the time of imaging a road marking with the back camera of a vehicle to a control target object. It is a flowchart of the driving assistance processing program in the driving assistance device which concerns on 1st Embodiment. It is a schematic block diagram of the driving assistance device which concerns on 2nd Embodiment.

Explanation of symbols

1 driving support device 2 vehicle 3 rear camera 5 vehicle ECU
6 Navigation ECU
7 Liquid crystal display 8 Speaker 9 Current position detection unit 11 Brake actuator 12 Accelerator actuator 42 Road marking DB

Claims (4)

An imaging means disposed in the vehicle for imaging the periphery of the vehicle;
In a driving assistance device having driving assistance means for assisting driving of a user based on an image taken by the imaging means,
Sign information storage means for storing the position information of the road marking formed on the road surface;
Road marking detection means for detecting a road marking formed on a road surface on which the vehicle travels based on an image captured by the imaging means;
Based on the road marking detected by the road marking detection means and the position information stored in the marking information storage means, a road distance from the vehicle to the control object associated with the road marking detected is calculated. An object distance calculating means for
The driving assistance device is characterized in that the driving assistance means has assistance for driving a user based on a calculation result of the object distance calculation means. Drive control means for controlling the drive of the vehicle,
The driving assistance apparatus according to claim 1, wherein the driving assistance unit performs driving control by the vehicle driving control unit based on a road distance from a vehicle to the control target. Provided with travel guidance means for providing guidance on travel to the user,
The driving assistance device according to claim 1, wherein the driving assistance means performs guidance by the travel guidance means based on a road distance from a vehicle to the control target. Current location detection means for detecting the current location of the vehicle;
Road marking presence determining means for determining whether or not there is a road marking within a predetermined range from the current position of the vehicle, based on the detection result of the current position detecting means and the position information stored in the marking information storage means; Have
4. The driving assistance according to claim 1, wherein the road marking detection unit detects the road marking when the road marking presence determination unit determines that the road marking is present. 5. apparatus.

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