JP4948338B2 - Inter-vehicle distance measuring device - Google Patents

Description

  The present invention relates to an inter-vehicle distance measuring device for measuring an inter-vehicle distance between a front and rear vehicle and a host vehicle, and in particular, captures a road with white lines with an in-vehicle imaging camera, and determines the inter-vehicle distance from the number of white lines captured. It is related with the inter-vehicle distance measuring device which calculates.

  With the improvement of the mounting rate of imaging cameras in automobiles, applications using imaging data are rapidly expanding. Many of these applications assist the driver's driving and improve the safety of the vehicle when traveling or parking. For example, in a system that displays obstacles around a vehicle, a plurality of super-wide-angle imaging cameras can be used to synthesize imaging data and display a 360 ° video around the vehicle. Further, by converting the viewpoint of the imaging data, it is also possible to display an image as if looking down from directly above the vehicle.

  Patent Document 1 relates to a navigation system, which sequentially images road surfaces including white lines on which the host vehicle is traveling, and measures the distance between white lines from those road surfaces. Based on the measured distance, it is determined whether the running road is an expressway or a general road.

  Patent Document 2 relates to a road type determination device, which captures a white line that divides a traveling lane drawn on a road surface, and based on the length of the white line extracted by image processing, is the road on which the vehicle is traveling an expressway? Judge whether it is a general road. Thus, the road type determination device can determine whether the host vehicle is present on any road even when the highway and the general road are running in parallel up and down.

JP 2001-28951 A JP-A-2005-114535

  As a technique for measuring the distance to an object or obstacle existing around a vehicle, there is a measurement system using an infrared laser, a millimeter wave radar, or the like. In these measurement systems, an infrared laser for distance measurement or the like must be newly installed in the vehicle, and the processing operation for calculating the distance is complicated, which increases the cost of the measurement system. There is.

  The present invention is made in order to solve the above-described problem, and can measure the distance to an object existing in front of or behind the host vehicle using an imaging camera mounted on the vehicle. It aims at providing the distance measuring device which suppressed cost.

  A distance measuring device according to the present invention images a road with a white line drawn to divide a driving lane, outputs imaging data, and detects whether an object exists on the road based on the imaging data Based on the number of white lines discriminated by the discriminating means, the discriminating means for discriminating the number of white lines between the object and the vehicle based on the imaging data when the detecting means detects the object Calculating means for calculating a distance from the own vehicle to the object. Preferably, the determination unit further determines the number of white line intervals between the object and the vehicle, and the calculation unit calculates the distance based on the number of white lines and the number of white line intervals.

  The distance measuring device according to the present invention captures an image of a road on which a white line is drawn in order to delimit a driving lane, outputs image data, and detects whether an object exists on the road based on the image data. A detection means, a determination means for determining the number of white line intervals between the object and the vehicle based on the imaging data, and a number of white line intervals determined by the determination means when the object is detected by the detection means; And calculating means for calculating a distance from the own vehicle to the object. Preferably, the determination unit further determines the number of white lines between the object and the vehicle, and the calculation unit calculates the distance based on the number of white line intervals and the number of white lines.

  Preferably, the determination unit includes the number of white lines and the white line interval between the end of the white line closest to the vehicle in the imaging data and the end of the white line closest to the object. Determine at least one of the numbers. The distance measuring device further includes road discriminating means for discriminating whether the road on which the vehicle is traveling is an expressway or a general road, and the calculating means is defined as an expressway or an ordinary road based on a discrimination result of the road discriminating means. The distance is calculated using the length of the white line or the interval between the white lines. The distance measuring device further includes display means for displaying the distance calculated by the calculating means on the display, and warns of approach to an object when the distance calculated by the calculating means is equal to or less than a preset value. A warning means may be included.

  The distance measurement program or the distance measurement method according to the present invention includes a step of imaging a road on which a white line is drawn in order to divide a driving lane, and whether or not an object exists on the road based on the imaging data captured in the imaging step. Detecting the number of white lines between the object and the vehicle based on the imaging data, and detecting the number of white lines from the vehicle to the object based on the determined number of white lines when the object is detected. Calculating a distance.

  According to the present invention, since the distance to the object is calculated using the imaging means, an existing vehicle-mounted camera can be used, and a low-cost distance measuring device can be provided. Furthermore, since the distance to the object is measured by the number of white lines or the number of white line intervals, the processing calculation is simple. Furthermore, by displaying the distance to the object, abnormal approach to the object can be avoided.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. Here, the example which measures the distance to the vehicle which exists on the road ahead or back of the own vehicle is used.

  FIG. 1 is a block diagram showing a configuration of an inter-vehicle distance measuring device 10 according to an embodiment of the present invention. The inter-vehicle distance measuring device 10 captures an image of a road on which a white line (center line) is drawn in order to divide a traveling lane, and outputs image data. Image processing that performs image processing on the image data output by the image capture camera 12 Unit 14, a vehicle position calculation unit 18 that calculates the vehicle position based on GPS satellites and autonomous navigation sensors, a memory 20 that stores an inter-vehicle distance measurement program, road map data, and the like, a display 22, and a display 22 display Display control unit 24 that controls the sound, speaker 26, sound output unit 28 that controls the sound output of speaker 26, and control unit 30 that controls each unit based on the inter-vehicle distance measurement program.

  The image processing unit 14 further includes a vehicle detection unit 15 that detects whether or not a vehicle is present in the imaging data, and when the vehicle detection unit 15 detects the vehicle, the detection vehicle and the host vehicle are detected using the imaging data. And a white line discriminating unit 16 for discriminating the number of white lines and / or the number of white line intervals between them.

  The imaging camera 12 is constituted by an optical system including an imaging element such as a CCD or CMOS sensor and a lens. For example, as shown in FIG. 2, the imaging camera 12a is attached to a bumper in the front part of the vehicle. The imaging camera 12a images the front of the vehicle with a viewing angle θ1. An imaging camera 12b is attached to a bumper at the rear of the vehicle, and the imaging camera 12b images the rear of the vehicle with a viewing angle θ2. The imaging camera 12 is not limited to the configuration shown in FIG. 2, and the imaging camera 12 may image each direction of the vehicle using more imaging cameras, and the mounting position is not necessarily limited to the bumper. .

  The image data captured by the imaging camera 12 can be displayed on the display 22 by the display control unit 24 for the purpose of driving assistance of the driver at the time of departure or parking of the host vehicle. Further, as will be described later, the imaging data is used for detecting whether or not a vehicle is present in front of or behind the host vehicle. When a vehicle is further detected, the number of white lines or the number of white line intervals is determined. Used for.

  The vehicle detection unit 15 detects whether there is a vehicle using a known image processing unit such as pattern matching. For example, it is possible to register vehicle pattern data to be detected in advance in the vehicle detection unit 15, compare the pattern data with the analyzed imaging data, and detect the vehicle based on the degree of comparison between the two. When the vehicle detection unit 15 detects a vehicle in the imaging data, the vehicle detection unit 15 outputs detection data including the coordinate position of the vehicle to the white line determination unit 16. Here, when a plurality of vehicles are detected at the same time, detection data relating to the vehicle closest to the host vehicle is selected and output.

  Similar to the vehicle detection unit 15, the white line determination unit 16 can extract an image related to the white line from the imaging data using a known image processing method such as pattern matching. Then, the white line determination unit 16 is based on the coordinate data of the vehicle received from the vehicle detection unit 15 and the number of white lines between the detected vehicle and the own vehicle and the white line interval between the white line and the white line. Determine the number of The white line determination unit 16 outputs the determined number of white lines and the number of white line intervals to the control unit 30.

  The memory 20 stores an inter-vehicle distance measurement program, road map data, and the like. The road map data includes white line data relating to the length of white lines and the length of white line intervals corresponding to the road type. FIG. 3 is a table showing road type white line data stored in the memory. On expressways, the length of white lines is defined as 8 m and the distance between white lines is defined as 12 m, as shown in FIG. 4 (a). On ordinary roads, the length of white lines is defined as shown in FIG. 4 (b). Is 5 m, and the length of the white line interval is 5 m.

  The control unit 30 reads road map data from the memory 20 based on the output of the vehicle position calculation unit 18 and determines whether the road on which the vehicle is traveling is an expressway or a general road. Further, the white line data of the corresponding road is selected based on the determination result. Further, the control unit 30 uses the number of white lines and / or the number of white line intervals determined by the white line determination unit 16 and the selected white line data to calculate the inter-vehicle distance from the own vehicle to the vehicle. .

  Next, the measurement operation in the inter-vehicle distance measuring device of the present embodiment and the warning operation for avoiding abnormal approach with another vehicle will be described with reference to the flowchart of FIG. First, a road ahead or behind the subject vehicle is imaged by the imaging camera 12, and imaging data is output to the image processing unit 14 (step S101). For example, when the host vehicle moves forward, a road ahead of the host vehicle may be imaged by the imaging camera 12a. It is arbitrary whether to image the front or the rear, and the front and the rear may be imaged simultaneously. The imaging direction may be selected according to a user instruction.

  FIG. 6 is an example of imaging data obtained by imaging a road ahead of the host vehicle. As shown in the figure, a plurality of white lines 52 are drawn at the approximate center of the road 50 in order to divide the driving lane. A forward vehicle 62 traveling in front of the host vehicle is displayed. This imaging data is displayed on the display 22 by the display control unit 24 (step S102).

  Next, the vehicle detection unit 15 performs image processing on the imaging data from the imaging camera 12, and detects whether or not a vehicle is present in the imaging data (step S103). For example, in the example illustrated in FIG. 6, the forward vehicle 62 in the imaging data is detected. When the vehicle is detected, the white line determination unit 16 extracts the white line 52 from the imaging data shown in FIG. 6 (step S104), and then determines the number of white lines and the number of white line intervals (step S105).

  FIG. 7 shows a white line between the preceding vehicle and the host vehicle. A region F surrounded by a dotted line is imaging data, that is, an imaging range. The white line determination unit 16 selects the end A of the white line 52a closest to the host vehicle 60 from the white lines 52a to 52d in the imaging range F, and the white line 52b closest to the rear part of the forward vehicle 62. The end B of is selected. As a result, the number M of white lines existing between the end A and the end B is two, the number N of white line intervals is two, and the number M of white lines is equal to the number N of white line intervals.

  FIG. 8 shows an example in which a white line exists in another manner between the preceding vehicle and the host vehicle. In the example shown in FIG. 8A, the end A of the white line 52a at the closest position to the own vehicle 60 in the imaging range F is the same as that in FIG. An end B1 of a certain white line 52d is selected. In this case, the number M of white lines existing between the end A and the end B1 is two, and the number N of white line intervals is three.

  Further, in the example shown in FIG. 8B, the end A1 of the white line 52b (52a is outside the imaging range) that is closest to the host vehicle is selected and is closest to the rear of the forward vehicle 62. An end B of a certain white line 52c is selected. In this case, the number M of white lines existing between the end A1 and the end B is two, and the number N of white line intervals is one. Thus, the number M of white lines and the number N of white line intervals vary depending on the positional relationship between the host vehicle and the preceding vehicle.

  Next, the control unit 30 measures the distance from the host vehicle to the preceding vehicle using the determination result of the white line determination unit 16. At this time, the control unit 30 refers to the output of the vehicle position calculation unit 18 and the road map data, and reads white line data (see FIG. 3) corresponding to the road on which the vehicle travels backward from the memory 20. The control unit 30 uses the number M of white lines, the number N of white line intervals, and the white line data received from the white line determination unit 16 to measure the inter-vehicle distance from the own vehicle to the preceding vehicle according to the following equation (step S106).

  For example, as shown in FIG. 7, if the number M of white lines between the own vehicle and the preceding vehicle is two, the number of white line intervals is two, and the traveling road is a highway, the approximate inter-vehicle distance is , (8 m × 2) + (12 m × 2) = 40 meters. In the case of a general road, the inter-vehicle distance = (5 m × 2) + (5 m × 2) = 20 meters. Similarly, in the case of FIG. 8A, the distance between vehicles is 52 meters if it is a highway, 25 meters if it is a general road, and in the case of FIG. The distance is 28 meters, and if it is a general road, the inter-vehicle distance is 15 meters.

  When measuring the inter-vehicle distance to the preceding vehicle, the control unit 30 displays the measurement result on the display (step S107). FIG. 9 is a display example of the measured inter-vehicle distance. In the display example shown in FIG. 9A, the inter-vehicle distance display 70 is combined with the imaging data of the vehicle front 62 displayed on the display 22. In addition to visual output, the control unit 30 may cause the audio output unit 28 to output the inter-vehicle distance as audio.

  In addition to this display example, as shown in FIG. 9B, the image data 72 by the imaging camera 12a is displayed on the display, the traveling speed display 74 of the own vehicle, and the inter-vehicle distance display 70 with the preceding vehicle. The traveling direction guidance 76 for the next intersection may be displayed together.

  Next, the control unit 30 determines whether or not the calculated inter-vehicle distance is equal to or less than a predetermined constant distance (step S108). For example, when the inter-vehicle distance is equal to or less than a certain distance, the risk of contact with the front and rear vehicles increases rapidly. Therefore, when it is determined that the inter-vehicle distance is equal to or less than a certain distance, the control unit 30 displays a warning on the display 22 via the display control unit 24 or emits a warning sound from the speaker 26 via the voice control unit 28. The user is urged to warn of approaching the front and rear vehicles (step S109). It is desirable to set the predetermined distance different according to the expressway or the general road.

  As described above, the inter-vehicle distance measuring device according to the present embodiment detects whether a vehicle exists from the imaging data, and determines the vehicle from the number of white lines and the number of white line intervals between the vehicle and the own vehicle. By calculating the inter-vehicle distance from the host vehicle and displaying it on the display, the user can recognize the inter-vehicle distance from the front and rear vehicles, and avoid an abnormal approach to the front and rear vehicles. The vehicle detection and distance measurement shown in FIG. 5 are performed at regular intervals, and the front and rear vehicles are regularly checked. In addition, since the inter-vehicle distance is calculated using an existing imaging camera such as a front imaging camera or a rear imaging camera mounted on the vehicle, there is no need to use an infrared sensor or a millimeter wave radar, thereby suppressing an increase in cost. Can do.

  In the above embodiment, the front of the host vehicle is imaged and the inter-vehicle distance between the front vehicle and the host vehicle is calculated. However, the present invention is not limited to this, and the rear side of the host vehicle is imaged. The inter-vehicle distance may be calculated. The target to be detected is not limited to a vehicle, but may be a two-wheeled vehicle, a person, an object, or other obstacles, and these targets may be stationary or moving. Furthermore, although the said Example used the road by which the driving lane was divided | segmented into two by the white line as an example, not only this but the road divided | segmented into the three or more driving lanes by the several white line may be sufficient. . Furthermore, the inter-vehicle distance measuring device of the present embodiment does not matter whether the own vehicle is running or stopped.

  FIG. 10 is a block diagram illustrating a configuration example of a navigation system to which the inter-vehicle distance measuring device is applied. The navigation system 100 includes an input unit 110 that receives an input from the user in addition to the inter-vehicle distance measuring device 10, and the control unit 30 searches for an optimal route from the vehicle position to the destination, or the route. The navigation function part 120 which guides is included. When the host vehicle is traveling, a road map around the host vehicle position is displayed on the display 22, and a mark indicating the host vehicle position is synthesized and displayed there.

  For example, as shown in FIG. 11, the display 22 is divided into two screen displays, a road map including a guide route to the destination is displayed on one screen 22a, and an imaging camera is displayed on the other screen 22b. The captured image data is displayed, and the distance between the front and rear vehicles is also displayed there.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments according to the present invention, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible.

  The inter-vehicle distance measuring device according to the present invention can be used as an inter-vehicle distance warning system when the vehicle is traveling. As a usage mode, it can be functionally coupled to an electronic device such as a navigation device or another computer.

It is a block diagram which shows the structure of the inter-vehicle distance measuring device which concerns on the Example of this invention. It is a top view which shows arrangement | positioning of the imaging camera attached to the vehicle. It is a table which shows the white line data memorize | stored in memory. 4A shows the definition of the white line on the expressway, and FIG. 4B shows the definition of the white line on the general road. It is a flowchart explaining the measurement operation | movement and warning operation | movement of the inter-vehicle distance measuring apparatus of a present Example. It is a figure which shows the imaging data which imaged the front direction of the own vehicle. It is a figure which shows the white line between a preceding vehicle and the own vehicle. It is a figure which shows the example in which a white line exists in another aspect between a preceding vehicle and the own vehicle. It is a figure which shows the example of a display of distance between vehicles. It is a block diagram which shows the structural example of the navigation system which adapted the inter-vehicle distance measuring device. It is a figure which shows the example of the 2 screen display in a navigation system.

Explanation of symbols

10: Inter-vehicle distance measuring device 12: Imaging camera 14: Vehicle detection unit 16: White line extraction unit 18: Own vehicle position calculation unit 20: Memory 22: Display 24: Display control unit 26: Speaker 28: Audio output unit 30: Control unit 50: Roads 52, 52a to 52d: White line 60: Own vehicle 62: Front vehicles A, A1, B, B1: End

Claims (13)

Imaging means for imaging a road on which a white line is drawn in order to divide a driving lane, and outputting imaging data;
Detecting means for detecting whether an object exists on the road based on the imaging data;
When an object is detected by the detection unit, a determination unit that determines the number of white lines between the object and the vehicle based on the imaging data;
Calculating means for calculating the distance from the vehicle to the object based on the number of white lines determined by the determining means;
A distance measuring device. 2. The determination unit according to claim 1, wherein the determination unit further determines the number of white line intervals between the object and the vehicle, and the calculation unit calculates a distance based on the number of white lines and the number of white line intervals. Distance measuring device. Imaging means for imaging a road on which a white line is drawn in order to divide a driving lane, and outputting imaging data;
Detecting means for detecting whether an object exists on the road based on the imaging data;
When an object is detected by the detection unit, a determination unit that determines the number of white line intervals between the object and the vehicle based on the imaging data;
Calculating means for calculating the distance from the vehicle to the object based on the number of white line intervals determined by the determining means;
A distance measuring device. The said discrimination | determination means further discriminate | determines the number of the white lines between the said object and the own vehicle, The said calculation means calculates distance based on the number of the said white line intervals, and the number of white lines. Distance measuring device. The determination means includes the number of white lines and the white line interval between the end of the white line closest to the vehicle in the imaging data and the end of the white line closest to the object. The distance measuring device according to claim 1, wherein at least one of the numbers is discriminated. The distance measuring device further includes road discriminating means for discriminating whether the road on which the vehicle is traveling is an expressway or an ordinary road, and the calculating means is an expressway or an ordinary road based on a discrimination result of the road discriminating means. The distance measuring device according to claim 1, wherein the distance is calculated using a white line length or a white line interval defined in 1. The distance measuring device according to any one of claims 1 to 6, further comprising display means for displaying the distance calculated by the calculating means on a display. The distance measuring device further includes a warning unit that warns of an approach to the object when the distance calculated by the calculating unit is equal to or less than a preset value. The described distance measuring device. A navigation device including the distance measuring device according to claim 1. Imaging a road with a white line drawn to divide the driving lane;
Detecting whether there is an object on the road based on the imaging data imaged in the imaging step;
When an object is detected, determining the number of white lines between the object and the vehicle based on the imaging data;
And a step of calculating a distance from the own vehicle to the object based on the determined number of white lines. The distance measuring program according to claim 10, wherein the determining step further determines the number of white line intervals, and the calculating step calculates a distance based on the number of white lines and the number of white line intervals. The distance measurement program according to claim 10 or 11, further comprising a step of displaying the imaging data and a step of combining the calculated distance with the imaging data. The distance measurement program further determines whether or not the distance to the object is equal to or less than a preset distance;
Issuing a warning when the distance is less than or equal to a preset value;
The distance measurement program according to any one of claims 10 to 12, comprising:

Images