Road surface drawing system

Abstract

To provide a road surface drawing system which can grasp a status of a pedestrian with good visibility.SOLUTION: A road surface drawing system includes a camera for photographing a front space of a vehicle, a controller which detects a pedestrian 100 existing in the front space and white lines of a road in front of the vehicle on the basis of image data obtained by the camera, and performs control so as to irradiate the road with light on the basis of the respective detection results, and a lamp unit which is controlled by the controller and irradiates with the road with light, wherein the controller controls the lamp unit so that a position on the road corresponding to a position of the pedestrian 100 is irradiated with a first bright line, when the pedestrian 100 exists and a relative distance between the pedestrian 100 and the vehicle is less than a threshold, and the first bright line is linear light in an extension direction of a central white line 110 provided on the road, and is emitted while overlapping the central white line 110.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a road surface drawing system.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2008-143510 (Patent Document 1) describes a warning irradiation device that irradiates the road surface with light that displays the direction of a person estimated to be dangerous from the host vehicle and the distance to the person, thereby alerting both the driver and the person regardless of the color of the person's clothing. As the light irradiated onto the road surface, lights in the shape of a T, a Y, an arrow, etc. (road surface drawing) that are irradiated so as to extend toward the person are described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the prior art described in Patent Document 1, when a pedestrian exists outside the white line on the oncoming lane side (sidewalk), in order to convey the presence and position of the pedestrian to the driver, complex character drawings such as a T are irradiated. However, when an oncoming vehicle passes between the host vehicle and the pedestrian in the oncoming lane, the complex character drawings such as a T hit the oncoming vehicle, so that the drawing does not face the pedestrian, and the driver loses sight of the position of the pedestrian. In addition, the light of the drawing can also cause glare to the driver of the oncoming vehicle. This problem occurs not only with complex character drawings but also, for example, with a single line drawing that extends straight from the host vehicle to the pedestrian. One of the objectives of the specific aspect according to the present disclosure is to provide a road surface drawing system that enables the driver of the host vehicle to visually recognize the situation of the pedestrian with good visibility.

Means for Solving the Problems

[0005] A road surface drawing system according to one embodiment of the present disclosure includes (a) a camera that photographs the space in front of a vehicle, (b) a controller that detects pedestrians present in the space in front of the vehicle and detects the white lines of the road in front of the vehicle based on image data obtained by the camera, and controls the illumination of the road based on the respective detection results, and (c) a lamp unit that illuminates the road under the control of the controller, (d) the controller controls the lamp unit so that a first bright line is illuminated at a position on the road corresponding to the position of the pedestrian when the pedestrian is present and the relative distance between the pedestrian and the vehicle is less than a threshold, and (e) the first bright line is a straight line of light along the direction of extension of the center white line provided between the vehicle's lane and the adjacent opposing lane on the road, and is illuminated superimposed on the center white line.

[0006] According to the above configuration, a road surface drawing system is provided that can clearly grasp the situation of pedestrians (accurate location, sense of distance, and whether or not they are entering the road). [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a block diagram showing the configuration of a road surface drawing system according to one embodiment. [Figure 2] Figure 2(A) is a schematic diagram showing an example of the installation of each lamp unit. Figure 2(B) is a schematic diagram showing an example of the configuration of the lamp unit. [Figure 3] Figure 3 shows an example of a computer system configuration. [Figure 4] Figure 4 is a flowchart showing the operation procedure of the road surface drawing system. [Figure 5] Figures 5(A) to 5(C) are diagrams illustrating the drawing patterns of the bright lines. [Figure 6] Figures 6(A) to 6(C) are diagrams illustrating the drawing patterns of the bright lines. [Figure 7]Figures 7(A) and 7(B) are diagrams illustrating the drawing method of the bright lines. [Figure 8] Figures 8(A) and 8(B) are diagrams illustrating the drawing patterns of the bright lines. [Figure 9] Figures 9(A) to 9(C) are diagrams illustrating the drawing patterns of the bright lines. [Figure 10] Figures 10(A) and 10(B) are diagrams illustrating the drawing method of the bright lines. [Figure 11] Figures 11(A) to 11(C) are diagrams illustrating the drawing patterns of the bright lines. [Modes for carrying out the invention]

[0008] Figure 1 is a block diagram showing the configuration of a road surface drawing system according to one embodiment. The road surface drawing system 1 of this embodiment consists of a controller 10, a camera 11, a raindrop sensor 12, a vehicle speed sensor 13, and a pair of lamp units 30L and 30R. This road surface drawing system 1 is mounted on the front of the vehicle and draws bright lines (line-shaped lights) on the road surface in front of the vehicle according to the situation of pedestrians present in front of the vehicle. Pedestrians include not only people walking but also people riding bicycles.

[0009] The controller 10 controls the light illumination by each headlight unit 30L, 30R. This controller 10 can be configured using a computer system that includes, for example, a processor (CPU: Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory or other storage device, and an input / output interface. In this embodiment, the controller 10 becomes capable of performing predetermined functions when a program previously stored in the storage device (or ROM) is read and executed by the processor.

[0010] Camera 11 captures the space in front of the vehicle and generates image data. Based on this image data, the image processing unit 20 of the controller 10 detects the location of pedestrians and other conditions. Note that the functions of the image processing unit 20 may also be provided on the camera 11 side.

[0011] The raindrop sensor 12 detects the amount of rainfall at the location where the vehicle is located and outputs a signal (or data) that indicates a change in accordance with the amount of rainfall. Various known types can be used as the raindrop sensor 12. For example, a sensor such as the one described in Japanese Patent Application Publication No. 2006-29807, which is installed on the inside of the vehicle's windshield and detects raindrops adhering to the outer surface of the glass by optical means, can be used.

[0012] The vehicle speed sensor 13 detects the vehicle's speed and outputs a vehicle speed signal (vehicle speed pulse). If the vehicle already has a vehicle speed sensor for other purposes, that sensor may be used as the vehicle speed sensor 13.

[0013] The vehicle's own position data 14 is generated by a position detection means (not shown) such as a car navigation system or GPS sensor installed in the vehicle, and is input to the vehicle's own position detection unit 221 of the controller 10.

[0014] A pair of lamp units 30L and 30R are mounted at predetermined positions on the left and right sides of the front of the vehicle and operate in response to control signals provided by the controller 10 to project a linear (line-shaped) beam of light to a desired position in front of the vehicle. Each lamp unit 30L and 30R includes a driver 31 and an LED array 32 driven by this driver 31.

[0015] The controller 10 described above is composed of an image processing unit 20, a vehicle position detection unit 21, a weather detection unit 22, a relative position calculation unit 23, a relative distance calculation unit 24, a boundary line calculation unit 25, and a road surface drawing control unit 26, which are functional blocks realized by program execution.

[0016] The image processing unit 20 performs image recognition processing on the image data generated by the camera 11 to detect the situation in front of the host vehicle, such as the position of a pedestrian, the position of a vehicle ahead (a preceding vehicle or an oncoming vehicle), and the white lines on the road.

[0017] The host vehicle position detection unit 21 detects the position of the host vehicle based on the host vehicle position data. To know the position of the host vehicle, this host vehicle position data 14 may be configured to include a car navigation system, and it is also possible to calculate whether the host vehicle is located in the city, on a road with a straight line of 100 m or more, or on a road with only a straight line of less than 100 m from the map information of this car navigation. The definition of a road in the present disclosure is a road with a good view that can be visually recognized by the driver. Therefore, not only straight roads but also curves are included if they can be seen through. In other words, intersections and S-shaped roads with a clear view ahead are also included as roads.

[0018] The weather detection unit 22 detects the weather condition, specifically the rainfall amount, based on the output of the raindrop sensor 13. When the rainfall amount exceeds a predetermined value, the weather detection unit 22 outputs that fact to the road surface drawing control unit 26.

[0019] The relative position calculation unit 23 detects the position and shape of the white lines existing in front of the host vehicle based on the image recognition result by the image processing unit 20.

[0020] The relative distance calculation unit 24 calculates the relative distance between the pedestrian and the host vehicle based on the current position detected by the host vehicle position detection based on the host vehicle position data and the image recognition result by the image processing unit 20.

[0021] When there is no white line on the road surface, the boundary line calculation unit 25 calculates a boundary line, which is a virtual line that can replace the white line, based on the image recognition result by the image processing unit 20.

[0022] The road surface drawing control unit 26 generates a control signal for projecting a bright line onto the road surface based on the position and shape of the white line determined by the relative position calculation unit 23, the relative distance between the pedestrian and the vehicle determined by the relative distance calculation unit 24, the boundary line determined by the boundary line calculation unit 25, and the weather conditions detected by the weather detection unit 22, and outputs the control signal to each lamp unit 30L, 30R.

[0023] Figure 2(A) is a schematic diagram showing an example of the installation of each lamp unit. Each lamp unit 30L and 30R is positioned at a predetermined location on the left and right sides of the front of the vehicle 50. In the illustrated example, lamp units 30L and 30R are positioned adjacent to lamp units 40L and 40R, respectively, which are used to illuminate high beams and low beams.

[0024] Figure 2(B) is a schematic diagram showing an example of the configuration of a lamp unit. The lamp unit 30L (30R) in the illustrated example consists of an LED array 32 having a plurality of LEDs (Light Emitting Diodes) arranged in two directions, and a lens 33 that projects the light emitted from the LED array 32. The LED array 32 is positioned so that its center substantially coincides with the focal point of the lens 33. By individually controlling the lighting state of each LED in the LED array 32 with a driver 31, a bright line can be projected onto a desired position on the road surface. The area to which the road surface drawing is projected is an area that includes at least both the high beam area and the low beam area in the front-rear direction (for example, an area within 100m from near the vehicle, or an area beyond 100m), and in the left-right direction, it is an area that includes at least the driving lane (including the white lines on the side of the driving lane and the center white line), and further includes the oncoming lane (including the white lines on the oncoming lane side). In this embodiment, the longitudinal direction is 100m from the vehicle itself, and the lateral direction is an area that includes both the driving lane and the oncoming lane.

[0025] The configuration of the lamp unit 30L is not limited to this, and various known configurations can be adopted. For example, a lamp unit with a light source bulb combined with a reflector or shielding plate may be used. Alternatively, a lamp unit equipped with a light source and liquid crystal elements, in which the light transmission state of each pixel of the liquid crystal elements can be individually controlled, may be used. Furthermore, a lamp unit equipped with a light-emitting element such as a laser diode and a scanning element such as a mirror device that scans the light emitted from the light-emitting element, in which the timing of the on / off of the light-emitting element and the scanning timing by the scanning element can be controlled, may be used.

[0026] Figure 3 shows an example of the configuration of a computer system. The controller 10 described above can be configured using a computer system like the one shown. The CPU (Central Processing Unit) 201 performs information processing by reading and executing the program 207 stored in the memory device 204. The ROM (Read-Only Memory) 202 stores basic control programs and the like necessary for the operation of the CPU 201. The RAM (Temporary Memory) 203 temporarily stores data necessary for information processing by the CPU 201. The memory device 204 is a large-capacity storage device for storing data and is composed of a hard disk drive or a solid-state drive. The communication device 205 performs processing related to data communication with other external devices. The input / output unit 206 is an interface for connecting with external devices and, in this embodiment, is used for connecting with the camera 11, the raindrop sensor 12, the vehicle speed sensor 13, and the lamp units 30L and 30R. The CPU 201 and other components are connected to each other via a bus so that they can communicate with each other.

[0027] Figure 4 is a flowchart illustrating the operation procedure of the road surface drawing system. Note that the order of each process can be changed as long as it does not cause inconsistencies in the control results, and other processes not described may be added, and these variations are not excluded. First, as a basic drawing pattern, as illustrated in Figures 5(A) to 5(C) and 6(A) to 6(C) which show the road ahead as seen from the vehicle, the operation procedure of the road surface drawing system 1 will be explained with reference to a pattern in which, when a pedestrian 100 is relatively far away on the opposite lane side, a relatively long bright line (second bright line) 113 is projected superimposed on the center white line 110, when the pedestrian 100 is relatively close, a relatively short bright line (first bright line) 114 is projected superimposed on the center white line 110, and when the position of the pedestrian 100 enters the inside (road side) of the white line 112 on the opposite lane side, a bright point 113 or 114 is flashed and projected.

[0028] Note that the triangles shown near the bright lines 113 or 114 in Figures 6(A) to 6(C) are merely a simulated representation of the flashing of bright lines 113 or 114 and do not actually project onto the road surface. Also, while the central white line 110 is shown as a dashed line in each figure, the central white line 110 may be a continuous straight line. Furthermore, although referred to as a "white line" for convenience, it may be a line of other colors (the same applies below).

[0029] If the vehicle speed detected by the vehicle speed sensor 13 is 10 km / h or more (Step S10; YES), and the image processing unit 20 detects a pedestrian on the opposite lane in front of the vehicle based on the image data obtained by the camera 11 (Step S11; YES), the relative distance calculation unit 24 calculates the relative distance between the pedestrian and the vehicle based on the current position detected by the vehicle position detection and the image processing results (Step S12). The relative position calculation unit 23 also detects the position and shape of the center white lines 110, 111, and 112 in front of the vehicle based on the image recognition results by the image processing unit 20 (Step S13). The calculated relative distance, position, and shape data are temporarily stored in memory.

[0030] If the relative distance between the pedestrian and the vehicle is greater than or equal to a predetermined threshold (for example, 100m or more) (Step S14; YES), and the pedestrian is outside the white line (Step S15; YES), the road surface drawing control unit 26 generates a control signal to continuously illuminate a relatively long bright line 113 so as to overlap the center white line 110, which is the lane marking between the vehicle's lane and the oncoming lane, and outputs this control signal to each lamp unit 30L, 30R (Step S16). As a result, as shown in Figure 5(A), the bright line 113 is continuously illuminated, overlapping the center white line 110. In this embodiment, the monitoring start was assumed to be within the high beam range, so the predetermined threshold was set to 100m. However, in urban areas, there may be no road 100m ahead because the roads with good visibility are short. In that case, the monitoring start may be assumed to be near the low beam range, and the predetermined threshold may be set to between 30m and 50m (for example, 40m). If map information from a car navigation system or similar indicates that the vehicle is in an urban area or that the section of road with good visibility is less than 100 meters long, the system may be configured to automatically change a predetermined threshold.

[0031] The long bright line 113 referred to here is a straight line of light that is approximately parallel to the center white line 110, that is, approximately parallel to the direction of the road's extension. The width of the bright line 113 is preferably set to be about the same as the width of the center white line 110 or slightly wider than the width of the center white line 110 at each illuminated position. If the white line 111 becomes the same or similar color as the drawn long bright line 113 due to deterioration or dirt, or if the brightness of the long bright line 113 is insufficient, if the bright line is wider than the width of the center white line 110, the portion of the drawn long bright line 113 that extends beyond the center white line 110 will be easier for the driver of the vehicle or pedestrians to see. In addition, the length of the long bright line 113 is a length that is necessary and sufficient to make the presence of pedestrians at a distance visible, for example, it is set to about 100m, the distance that high beams can reach, but it may also be about 40m, the distance that low beams can reach. Furthermore, since a relatively long emission line only needs to be distinguishable from a short emission line, a length of 9m to 100m, which is more than three times the length of a short emission line, can be considered sufficient.

[0032] Furthermore, if the relative distance between the pedestrian and the vehicle is greater than or equal to a predetermined threshold (for example, 100m or more) (Step S14; YES), and the pedestrian is located inside the white line, i.e., within the road (Step S15; NO), the road surface drawing control unit 26 generates a control signal to flash a long bright line 113 superimposed on the center white line 110, and outputs this control signal to each lamp unit 30L, 30R (Step S17). As a result, as shown in Figure 6(A), a long bright line 113 flashes and is superimposed on the center lane 110. In this embodiment, since the start of monitoring was assumed to be within the high beam area, the predetermined threshold (relative distance threshold) was set to 100m. However, in urban areas, there are short stretches of road with good visibility, so there may not be a road 100m ahead. In that case, the start of monitoring may be assumed to be near the low beam area, and the predetermined threshold may be set to between 30m and 50m (for example, 40m). In other words, if the vehicle's location is known in advance from map information such as a car navigation system to be in an urban area or on a road section with good visibility of 100m or less, the predetermined threshold can be automatically changed.

[0033] If the relative distance between the pedestrian and the vehicle is less than a threshold (step S14; NO), and the pedestrian is outside the white line, i.e., outside the road (such as a sidewalk) (step S18; YES), the road surface drawing control unit 26 generates a control signal to continuously illuminate a relatively short bright line 114 superimposed on the center white line 110 at a position corresponding to the pedestrian's position, and outputs this control signal to each lamp unit 30L, 30R (step S19). As a result, a short bright line 114 is continuously illuminated superimposed on the center lane 110, as shown in Figure 5(B) or Figure 5(C).

[0034] The short bright line 114 referred to here consists of a straight line of light that is approximately parallel to the central white line 110, that is, approximately parallel to the direction in which the road extends. The width of the short bright line 114 is preferably set to be about the same as or slightly wider than the central white line 110 at each illuminated position. If the white line 111 becomes the same or similar color as the drawn bright line 113 due to deterioration or dirt, or if the brightness of the bright line 113 is insufficient, if the bright line 114 is wider than the width of the white line 111, the portion of the drawn bright line 113 that extends beyond the white line 111 will be easier for the driver of the vehicle or pedestrians to see. Furthermore, the length of the short bright line 114 is a length that is necessary and sufficient to make the position of a pedestrian visible (a length wider than the width of a person, for example, 0.5m to 2m) and is relatively shorter than the bright line 113 described above, for example, it is preferably about 1.5m, which is the length of a person's height or the length of a person's outstretched arms. When the drawing position is far away, such as 100m, a bright line size of 1.5m in length and the same width as the white line (or slightly wider) may be difficult for the driver of the vehicle to see. Therefore, the width and length may be changed to, for example, 1.5 to 2 times to improve visibility. When the relative distance becomes shorter (for example, 50m or less), the width and length may be shortened and returned to the predetermined width and length (the adjustment of width and length may be gradual or stepwise). This can be achieved by the relative distance calculation unit 24 detecting that the relative distance is far, generating a control signal for the road surface drawing control unit 26 to draw the bright line 113 with adjusted width and length, and outputting this control signal to each lamp unit 30L, 30R.

[0035] If the relative distance between the pedestrian and the vehicle is less than a threshold (step S14; NO), and the pedestrian is located inside the white line, i.e., within the road (step S18; NO), the road surface drawing control unit 26 generates a control signal to flash a relatively short bright line 114 superimposed on the center white line 110 at a position corresponding to the pedestrian's location, and outputs this control signal to each lamp unit 30L, 30R (step S20). As a result, a short bright line 114 flashes and is superimposed on the center lane 110, as shown in Figure 6(B) or Figure 6(C).

[0036] When any of steps S16, S17, S19, or S20 is executed, the process returns to step 10. As the process from step S10 onward is repeated, the long line 113 switches to the short line 114 in accordance with the change in the relative position of the pedestrian 100, or the illumination position of the short line 114 is changed according to the pedestrian's position. Also, when the pedestrian moves from outside the white line to inside the white line, the long line 113 or the short line 114 is switched to flashing illumination. The long line illuminates, allowing the driver to recognize the presence of a pedestrian at a distance, thus enabling them to prepare in advance for driving while paying attention to the pedestrian. The short line illuminates, allowing the driver to intuitively recognize the pedestrian's position, and furthermore, because the short line is illuminated over the white line, and the short line appears to be shining continuously on the white line, the driver can recognize the relative distance between their vehicle and the pedestrian, that is, the pedestrian's exact position. Furthermore, the change in the way the emission lines illuminate allows the driver to intuitively recognize a change in the pedestrian's situation (in this case, whether or not they have entered the road), enabling them to drive while paying attention to the pedestrian's behavior.

[0037] For example, if at one point pedestrian 100 is far from the vehicle and outside the white line, and at the next point pedestrian 100 is inside the white line, the drawing mode transitions from the continuous illumination shown in Figure 5(A) to the flashing illumination shown in Figure 6(A). Also, if pedestrian 100, which was far from the vehicle and outside the white line at one point, moves relatively closer to the vehicle at the next point, and then at the point after that pedestrian 100 is inside the white line, the drawing mode transitions from the continuous illumination shown in Figure 5(A), the continuous illumination shown in Figure 5(B), and the flashing illumination shown in Figure 6(B). Because short bright lines are projected onto the white line, the short bright lines appear to be moving closer and closer along the continuous white line (and they move in one direction), allowing the driver to intuitively perceive the distance to the pedestrian.

[0038] On the other hand, if the vehicle speed is less than 10 km / h (step S10; NO), or if the vehicle speed is 10 km / h or more but there are no pedestrians (step S11; NO), the illumination of the bright lines by the road surface drawing control unit 26 ends (step S21). If illumination of the bright lines was not performed in the first place, that state is maintained. In this embodiment, step S10 is set to "the vehicle speed is 10 km / h or more," but vehicle speed is just an example, and if the car is in motion, step 10 will be YES, or to put it extremely, step 10 may be set to YES when the ignition is turned ON before driving. Also, since steps S15, S16, and S17 are for remote monitoring, if the vehicle's position detected by the car navigation system, etc. is in an urban area where remote monitoring is not necessary, the control may be stopped as it is unlikely to be used, or the system may be configured using only steps S18, S19, and S20 which use short bright lines, without including them in the system from the beginning.

[0039] Figures 7(A) and 7(B) illustrate an example of how the bright line is drawn. The drawing method described above assumes that a central white line and side white lines exist in the direction of travel of the vehicle. However, if a central white line or the like does not exist or cannot be detected due to weather conditions, a long bright line 113a corresponding to the central white line can be projected, as illustrated in Figure 7(A). Specifically, based on the edge contours 121 and 122 on both sides of the road surface detected by the image processing unit 20, the boundary line calculation unit 25 calculates a boundary line, which is a virtual line indicating the boundary where the vehicle and pedestrians 110 are considered to be able to pass safely. The boundary line is a virtual line that extends in the direction of the road at approximately the center of the road and can be determined based on the width or shape of the road.

[0040] For example, the road width, which is the distance between the end contours 121 and 122, can be detected, and a boundary line can be set at a certain distance from either the end contour 121 or the end contour 122 based on this road width. Then, a long bright line 113a can be projected along this determined boundary line. This long bright line 113a can be used as a substitute for the center line, and its length can be, for example, within 100m from the vehicle's position. Furthermore, the long bright line 113a is projected continuously regardless of the distance between the pedestrian 100 and the vehicle. In this embodiment, the monitoring start was assumed to be within the high beam area, so the predetermined threshold was set to 100m. However, in urban areas, there are short stretches of road with good visibility, so there may not be a road 100m ahead. In that case, the monitoring start may be assumed to be near the low beam area, and the predetermined threshold may be set between 30m and 50m (for example, 40m).

[0041] Furthermore, as shown in Figure 7(A), when the pedestrian 100 is located outside the road (outside the edge contour 122), a relatively long bright line 113a can be superimposed on a virtual boundary line, and a relatively short bright line 114a corresponding to the pedestrian 100's position can be superimposed on the long bright line 113a for illumination. Since this short bright line 114a appears to shine on the long bright line 113a, the driver can recognize the pedestrian's exact position. In this case, it is preferable that the short bright line 114a has a higher illuminance than the long bright line 113a, or that it is illuminated with a different color tone than the bright line 113a. This is because the visibility of the bright line 114a can be further improved. Even if the illuminances of the bright lines 113a and 114a are about the same, the illumination of the bright line 114a will be higher, making it visible. Furthermore, as shown in Figure 7(B), when the pedestrian 100 moves inside the road (inside the edge contour 122), the bright line 114a is illuminated in a flashing manner. This flashing of the short bright line 114a changes the pedestrian's situation, allowing the driver to intuitively recognize that the pedestrian has entered the road and drive while paying attention to the pedestrian's actions. The short bright line 114a may also be wider than the long bright line 113a. This is because if it is wider than the long bright line 113a, the short bright line 114a that extends beyond the long bright line 113a will be easier for the driver of the vehicle or a pedestrian to see.

[0042] Figures 8(A) and 8(B) illustrate an example of how the bright lines are drawn. When it is raining in the area where the vehicle is traveling, the visibility of the bright lines projected onto the road surface may decrease, so it is preferable to implement the same drawing method as when there is no central white line as described above. The occurrence of rain is detected by the weather detection unit 22 based on the output of the raindrop sensor 12. For example, if a rainfall amount exceeding a predetermined value is detected, the weather detection unit 22 outputs a message to the road surface drawing control unit 26 to that effect.

[0043] Specifically, as illustrated in Figure 8(A), regardless of the distance between the pedestrian 100 and the vehicle, a long bright line 113a can be projected onto the center white line 110, and then a short bright line 114a corresponding to the position of the pedestrian 110 can be projected. Furthermore, as shown in Figure 8(B), when the pedestrian 100 moves inside the lane (inside the white line 112), the bright line 114a is projected in a flashing manner. In this case, it is preferable that the short bright line 114a has a higher illuminance than the long bright line 113a, or that it is projected in a different color tone than the bright line 113a. In road conditions where the center white line 110 is difficult to see due to rain, even if the short bright line 114a is projected onto the center white line 110, the driver will only be able to see the short bright line 114a, making the relative position of the short bright line 114a unclear, and making it difficult for the driver to accurately recognize the position of the pedestrian. In this embodiment, since a long bright line 113a is projected instead of the hard-to-see central white line 110, the short bright line 114a appears to glow on the long bright line 113a, making the relative position of the short bright line 114a clear, and enabling the driver to recognize the pedestrian's exact position. Furthermore, by switching the short bright line 114a to flashing mode, the driver can intuitively recognize that the pedestrian situation has changed and that a pedestrian has entered the road, allowing them to drive while paying attention to the pedestrian's actions.

[0044] Figures 9(A) to 9(C) illustrate an example of how the bright lines are drawn. When there are multiple pedestrians, bright lines can be projected corresponding to the position of each pedestrian. Specifically, as illustrated in Figure 9(A), when multiple pedestrians 100a and 100b are located outside the white line 112, short bright lines 114b and 114c corresponding to the positions of pedestrians 100a and 100b are projected onto the central white line 110.

[0045] Furthermore, as illustrated in Figure 9(B), if one pedestrian 100a enters the inside of the white line 112 (in the roadway), the corresponding bright line 114b is illuminated by flashing. Similarly, as illustrated in Figure 9(C), if the other pedestrian 100b enters the inside of the white line 112 (in the roadway), the corresponding bright line 114c is illuminated by flashing. Although not shown in the illustration, if either pedestrian 100a or 100b enters the inside of the white line 112, the respective bright lines 114b and 114c are illuminated by flashing. As a result, multiple short bright lines 114b and 114c appear to shine on the center white line 100, allowing the driver to recognize that multiple pedestrians are present outside the white line on the opposite lane ahead (on the sidewalk, etc.). Furthermore, if some of the short bright lines 114b or 114c switch to flashing, the driver can intuitively recognize that a pedestrian has entered the road. This allows the driver to focus their attention on the pedestrian corresponding to the flashing short bright line among multiple pedestrians, making it easier to react when a pedestrian and the vehicle are approaching.

[0046] Furthermore, in the embodiment of the bright line drawing shown in Figures 9(A) to 9(C), a relatively long bright line may be projected onto the central white line 110, and then the aforementioned bright lines 114b and 114c may be projected on top of it (continuous projection / flashing projection). This is because, on rainy days, the central white line 110 becomes difficult to see, so projecting the shorter bright lines 114b and 114c onto the longer bright line makes it easier for the driver to recognize the relative position of the shorter bright line, thus making it easier to accurately recognize the position of pedestrians.

[0047] Figures 10(A) to 10(B) and 11(A) to 11(C) illustrate examples of how the bright lines are drawn. In each of the drawing methods described above, the bright lines were projected onto the central white line 110 (or an equivalent boundary line). However, while there are no vehicles in the oncoming lane, the bright lines may be projected onto the white line 112 on the oncoming lane side, and when a vehicle appears in the oncoming lane, the bright lines may be projected onto the central white line 110. The presence or absence of oncoming vehicles can be determined by the image recognition results from the image processing unit 20.

[0048] For example, as shown in Figure 10(A), when there are no vehicles in the oncoming lane, the relative distance between the pedestrian 100 and the vehicle is 100m or more, and the pedestrian 100 is outside the white line 112 on the oncoming lane side, a relatively long bright line 115 is continuously projected over the white line 112. Also, as shown in Figure 10(b), when the pedestrian 100 enters the area inside the white line 112, the bright line 115 is flashed.

[0049] Then, as shown in Figure 11(A), when a vehicle 130 appears in the oncoming lane, the illumination of the bright line 115 superimposed on the white line 112 is stopped, and a relatively long bright line 113 is continuously illuminated superimposed on the center white line 110. Also, when the relative distance between the pedestrian 100 and the vehicle is less than 100m, and the pedestrian 100 is outside the white line 112 on the oncoming lane side, a relatively short bright line 114 is continuously illuminated superimposed on the center white line 110 corresponding to the position of the pedestrian 100. Furthermore, as shown in Figure 11(C), when the pedestrian 100 enters the inside of the white line 112, the bright line 114 is flashed and illuminated.

[0050] According to the above embodiment, by superimposing short bright lines onto the central white line or a long bright line, even when an oncoming vehicle passes, the short bright lines do not cross the oncoming lane, thus preventing them from hitting the oncoming vehicle, impairing the drawing function, or causing glare to the driver of the oncoming vehicle. Furthermore, the short bright lines shining on the central white line or a long bright line provide a road surface drawing system that allows the driver to clearly perceive the situation of pedestrians (accurate position, distance, and whether they have entered the road). Specifically, the presence and precise position of pedestrians are conveyed to the driver by straight bright lines along the central white line, so the driver's area of ​​focus is narrowed compared to when complex lights such as T-shapes are projected, making the pedestrian's position clearer and easier to understand. In addition, the driver's eye movement is reduced because the area of ​​focus is narrowed. This is especially noticeable when the pedestrian is at a distance. As a result, it becomes possible to clearly perceive the situation of pedestrians.

[0051] Furthermore, in this embodiment, the drawing mode of the illuminated line is switched from continuous illumination to flashing illumination depending on the pedestrian's position relative to the white line (inside / outside the white line), making it easier to grasp changes in the pedestrian's situation. In addition, the drawing mode of the illuminated line is also switched in the case of bad weather or when the white line is absent (including cases where it cannot be detected), making it easier to grasp changes in the pedestrian's situation. Moreover, in particular, the drawing modes shown in Figures 10(A) and 10(B) illuminate the illuminated line at the pedestrian's feet, which has the advantage of making it easier to draw attention to pedestrians who are looking down, for example, to operate a smartphone.

[0052] Furthermore, this disclosure is not limited to the embodiments described above, and can be implemented in various modified forms within the scope of the gist of this disclosure.

[0053] This disclosure has the following features:

[0054] (Note 1) A camera that photographs the space in front of the vehicle, A controller that detects pedestrians in the space ahead based on image data obtained by the camera, detects the white lines on the road in front of the vehicle, and controls the illumination of the road based on the respective detection results. A lamp unit that illuminates the road with light under the control of the controller, Includes, The controller controls the lamp unit so that, when a pedestrian is present and the relative distance between the pedestrian and the vehicle is less than a threshold, a first emission line is projected onto a position on the road corresponding to the pedestrian's position. The first luminous line is a straight line of light along the direction of extension of the median white line provided between the vehicle's lane and the adjacent oncoming lane on the road, and is projected onto the median white line. Road surface drawing system. (Note 2) The controller controls the lamp unit such that the first bright line is continuously illuminated when the pedestrian's position is outside the road beyond the white line on the opposite lane side, and the first bright line flashes when the pedestrian's position is inside the road beyond the white line on the opposite lane side. The road surface drawing system described in Appendix 1. (Note 3) The controller controls the lamp unit to project a second emission line, which is a straight line of light longer than the first emission line, onto the central white line when a pedestrian is present in the forward space and the relative distance between the pedestrian and the vehicle is greater than or equal to the threshold. A road surface marking system as described in Appendix 1 or 2. (Note 4) The controller determines that the pedestrian's position is opposite the opposing Lane If the pedestrian is outside the road beyond the aforementioned white line on the side, the second bright line is continuously projected, and the pedestrian's position is opposite the road. Lane The lamp unit is controlled so that the second bright line flashes when it is inside the road beyond the white line on the side. The road surface drawing system described in Appendix 3. (Note 5) The illumination position of the first emission line changes as the position of the pedestrian moves. A road surface drawing system as described in any of the appendices 1 to 4. (Note 6) Equipped with a raindrop sensor, If the controller detects that it is raining in the space ahead based on the output of the raindrop sensor, it will continue to illuminate the second emission line regardless of the relative distance between the pedestrian and the vehicle, and will control the lamp unit to illuminate the first emission line superimposed on the second emission line. A road surface marking system as described in Appendix 3 or 4. (Note 7) The first emission line is irradiated with a higher illuminance than the second emission line and / or with a different color tone than the second emission line. The road surface drawing system described in Appendix 6. (Note 8) If the controller cannot detect the central white line, it calculates a boundary line based on the width or shape of the road, which is a virtual line extending along the direction of the road and positioned approximately in the center of the road, and controls the lamp unit to illuminate the second emission line along the boundary line regardless of the relative distance between the pedestrian and the vehicle, and to illuminate the first emission line superimposed on the second emission line. A road surface marking system as described in Appendix 3 or 4. (Note 9) The first emission line is irradiated with a higher illuminance than the second emission line and / or with a different color tone than the second emission line. The road surface drawing system described in Appendix 8. (Note 10) The controller controls the lamp unit so that, when there are multiple pedestrians, the first emission line is projected onto each of the positions on the road corresponding to the position of each pedestrian, regardless of the relative distance between each pedestrian and the vehicle. The road surface drawing system described in appendices 1 to 9. (Note 11) If, among the multiple pedestrians corresponding to the first illuminated lines, at least one pedestrian is located inside the road beyond the white line, the lamp unit is controlled to flash the first illuminated line corresponding to the pedestrian located inside the road. The road surface drawing system described in Appendix 10. [Explanation of symbols]

[0055] 1: Road surface drawing system, 10: Controller, 11: Camera, 12: Raindrop sensor, 13: Vehicle speed sensor, 14: Vehicle position data, 20: Image processing unit, 21: Vehicle position detection unit, 22: Weather detection unit, 23: Relative position calculation unit, 24: Relative distance calculation unit, 25: Boundary line calculation unit, 26: Road surface drawing control unit, 30L, 30R: Lamp unit, 31: Driver, 32: LED array, 100: Pedestrian, 110: Center white line, 111, 112: White lines, 113, 114: Bright lines

Claims

1. A camera that photographs the space in front of the vehicle, A controller that detects pedestrians in the space ahead based on image data obtained by the camera, detects the white lines on the road in front of the vehicle, and controls the illumination of the road based on the respective detection results. A lamp unit that illuminates the road with light under the control of the controller, Includes, The controller controls the lamp unit so that, when a pedestrian is present and the relative distance between the pedestrian and the vehicle is less than a threshold, a first emission line is projected onto a position on the road corresponding to the pedestrian's position. The first luminous line is a straight line of light along the direction of extension of the median white line provided between the vehicle's lane and the adjacent oncoming lane on the road, and is projected onto the median white line. Road surface drawing system.

2. The controller controls the lamp unit such that the first bright line is continuously illuminated when the pedestrian's position is outside the road beyond the white line on the opposite lane side, and the first bright line flashes when the pedestrian's position is inside the road beyond the white line on the opposite lane side. The road surface drawing system according to claim 1.

3. The controller controls the lamp unit to project a second emission line, which is a straight line of light longer than the first emission line, onto the central white line when a pedestrian is present in the forward space and the relative distance between the pedestrian and the vehicle is greater than or equal to the threshold. The road surface drawing system according to claim 1.

4. The controller controls the lamp unit such that the second bright line is continuously illuminated when the pedestrian's position is outside the road beyond the white line on the opposite lane side, and the second bright line flashes when the pedestrian's position is inside the road beyond the white line on the opposite lane side. The road surface drawing system according to claim 3.

5. The illumination position of the first emission line changes as the position of the pedestrian moves. The road surface drawing system according to claim 1.

6. Equipped with a raindrop sensor, If the controller detects that it is raining in the space ahead based on the output of the raindrop sensor, it will continue to illuminate the second emission line regardless of the relative distance between the pedestrian and the vehicle, and will control the lamp unit to illuminate the first emission line superimposed on the second emission line. The road surface drawing system according to claim 3.

7. The first emission line is irradiated with a higher illuminance than the second emission line and / or with a different color tone than the second emission line. The road surface drawing system according to claim 6.

8. If the controller cannot detect the central white line, it calculates a boundary line based on the width or shape of the road, which is a virtual line extending along the direction of the road and positioned approximately in the center of the road, and controls the lamp unit to illuminate the second emission line along the boundary line regardless of the relative distance between the pedestrian and the vehicle, and to illuminate the first emission line superimposed on the second emission line. The road surface drawing system according to claim 3.

9. The first emission line is irradiated with a higher illuminance than the second emission line and / or with a different color tone than the second emission line. The road surface drawing system according to claim 8.

10. The controller controls the lamp unit so that, when there are multiple pedestrians, the first emission line is projected onto each of the positions on the road corresponding to the position of each pedestrian, regardless of the relative distance between each pedestrian and the vehicle. The road surface drawing system according to claim 1.

11. If, among the multiple pedestrians corresponding to the first bright line, at least one pedestrian is located inside the road beyond the white line, the lamp unit is controlled to flash the first bright line corresponding to the pedestrian located inside the road. The road surface drawing system according to claim 10.

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