Vehicle forward viewing device

Abstract

Provided is a vehicle forward viewing device capable of preventing erroneous detection of objects such as nearby vehicles. A vehicle forward viewing device (10) mounted on a vehicle Va comprises: a right optical probe device which emits a laser beam group that forms a dot pattern in a right measurement target region set a predetermined reference distance in front of the vehicle; a left optical probe device which emits a laser beam group that forms a dot pattern in a left measurement target region set the predetermined reference distance in front of the vehicle; and a detection camera device which captures an image of return light that has been emitted from the right optical probe device and reflected by an object present in the right measurement target region, and generates a right distance image as a primary distance image having distance values as pixel values, and which meanwhile captures an image of return light that has been emitted from the left optical probe device and reflected by an object present in the left measurement target region, and generates a left distance image as a primary distance image having distance values as pixel values.

Description

Vehicle forward visibility device

[0001] The present disclosure relates to a vehicle forward visibility device.

[0002] A vehicle forward visibility device is known that uses LiDAR to sense objects such as surrounding vehicles in the area ahead of the vehicle (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-505

[0004] However, the vehicle forward visibility device described in Patent Document 1 has a problem in that it does not provide a sufficient mechanism for preventing erroneous detection of objects such as surrounding vehicles.

[0005] The present disclosure has been made to solve such problems, and aims to provide a vehicle forward visibility device that can prevent erroneous detection of objects such as surrounding vehicles.

[0006] The vehicle forward visibility device according to the present disclosure is a vehicle forward visibility device mounted on a vehicle, and includes: a right optical probe device provided on the right side of the front end of the vehicle and irradiating a group of laser beams that form a dot pattern in a right measurement target area set at a predetermined reference distance ahead of the vehicle; a left optical probe device provided on the left side of the front end of the vehicle and irradiating a group of laser beams that form a dot pattern in a left measurement target area set at the predetermined reference distance ahead of the vehicle; and a detection camera device that captures returned light irradiated from the right optical probe device and reflected by objects present in the right measurement target area, and generates a right distance image as a primary distance image in which pixel values ​​are distance values, and conversely, captures returned light irradiated from the left optical probe device and reflected by objects present in the left measurement target area, and generates a left distance image as a primary distance image in which pixel values ​​are distance values, wherein the right measurement target area and the left measurement target area are arranged symmetrically and at least partially overlap each other in front of the vehicle in the horizontal direction.

[0007] With this configuration, it is possible to provide a vehicle forward visibility device that can prevent erroneous detection of objects such as surrounding vehicles.

[0008] This is because the right measurement target area and the left measurement target area are arranged symmetrically left and right, and overlap at least partially with each other in front of the vehicle (own vehicle) in the horizontal direction. Therefore, if an object (e.g., a preceding vehicle) is present in this overlapping area, two distances to the object are obtained: a distance based on the right distance image and a distance based on the left distance image.

[0009] In addition, in the above-mentioned vehicle forward visibility device, the outer shape of the right measurement target area may be a trapezoid whose vertical width increases from the center of the vehicle width toward the right side of the vehicle width, and the outer shape of the left measurement target area may be a trapezoid whose vertical width increases from the center of the vehicle width toward the left side of the vehicle width.

[0010] In addition, in the above-mentioned vehicle forward visibility device, the dot density of the dot pattern formed in the right measurement target area may be set to be higher toward the center of the vehicle width direction and lower toward the right side of the vehicle width direction, and the dot density of the dot pattern formed in the left measurement target area may be set to be higher toward the center of the vehicle width direction and lower toward the left side of the vehicle width direction.

[0011] In addition, the vehicle forward visibility device may further include an object distance calculation unit that calculates the distance to an object located in the overlapping area between the right measurement target area and the left measurement target area based on the distance between the inner perpendiculars of the right measurement target area and the inner perpendicular of the left measurement target area.

[0012] The device for visually recognizing a forward direction of a vehicle may further include a dot density detection unit that detects a period of change in dot density within an overlapping area between the right measurement target area and the left measurement target area.

[0013] In addition, the vehicle forward visibility device may further include a bracket to which a lamp unit is attached, and an optical axis adjustment mechanism that adjusts the optical axis of the lamp unit by tilting the bracket, and the optical probe device may be attached to the bracket.

[0014] The above-described vehicle forward visual confirmation device may further include a secondary distance image generation unit that generates a secondary distance image to be transmitted to another device based on the right distance image and the left distance image.

[0015] In addition, in the above-mentioned vehicle forward visibility device, the right optical probe device and the left probe device each may have a plurality of light-emitting elements corresponding to a plurality of measurement distances, and may be switched to one of the plurality of light-emitting elements according to the vehicle speed of the vehicle, and the detection camera device may have a plurality of image-capturing elements corresponding to a plurality of measurement distances, and may be switched to one of the plurality of image-capturing elements according to the vehicle speed of the vehicle.

[0016] The present disclosure makes it possible to provide a vehicle forward visibility device that can prevent erroneous detection of objects such as surrounding vehicles.

[0017] 1 is a schematic diagram of a vehicle forward visual confirmation device 10. FIG. 2 is a front view of a vehicle Va to which the vehicle forward visual confirmation device 10 is attached. ２０Ｒ and left measurement target area A ２０Ｌ This is an example of the right measurement target area A. ２０Ｒ and left measurement target area A ２０Ｌ 9A. An example of a reference distance. An example of a reference distance. A schematic diagram of the right optical probe device 20R. A VIIB-VIIB cross-sectional view of FIG. 7A. A VIII-VIII cross-sectional view of FIG. 2. A schematic diagram of the detection camera device 30. A IXB-IXB cross-sectional view of FIG. 9A. A flowchart of an example of the operation of the vehicle forward visibility device 10. An example of a flowchart of an imaging process. An example of a flowchart of a secondary distance image generation process. An example of a flowchart of an object distance calculation process. A diagram showing each element in a formula for calculating the distance Lc to the object. An example of a flowchart of a dot density detection process. (a) to (c) Diagrams showing how the dot density changes periodically. Right measurement target area A ２０Ｒ and left measurement target area A ２０Ｌ 1 is a modified example of the light emitting element 21 of the optical probe device 20. ２０Ｒ and left measurement target area A ２０Ｌ1 is a modified example of the above. FIG. 1 is a schematic configuration diagram of a vehicle forward visibility device 10A of embodiment 2. FIG. 2 is an example of a processing code generation process. FIG. 3 is an example of an out-of-range condition and a processing code generated when the out-of-range condition is satisfied. FIG. 4 is an example of a transition state condition and a processing code generated when the transition state condition is satisfied. FIG. 5 is an example of an effective condition and a processing code generated when the effective condition is satisfied. FIG. 6 is an example of transmission data (packet) including a processing code and a composite distance image. FIG. 7 is a flowchart of an example of the operation of a vehicle forward visibility device 10A.

[0018] Hereinafter, a vehicle forward visibility device 10 according to an embodiment of the present invention will be described with reference to the accompanying drawings. Corresponding components in the various drawings are designated by the same reference numerals, and redundant description will be omitted.

[0019] First Embodiment FIG. 1 is a schematic diagram of a vehicle forward visual confirmation device 10 according to a first embodiment.

[0020] The vehicle forward visual confirmation device 10 is a forward information acquisition device that provides information about the area ahead of the vehicle to the driving assistance device when the vehicle is traveling mainly on suburban roads at medium to high speeds (for example, 40 to 120 km / h).

[0021] As shown in Fig. 1, the vehicle forward visibility device 10 includes optical probe devices 20 (right optical probe device 20R, left optical probe device 20L), a detection camera device 30, a control device 40, and a driving assistance device 60. The optical probe devices 20 and the detection camera devices 30 constitute a LiDAR device. The vehicle forward visibility device 10 is mounted on a vehicle such as an automobile. Hereinafter, the vehicle on which the vehicle forward visibility device 10 is mounted is referred to as the host vehicle Va.

[0022] FIG. 2 is a front view of the vehicle Va to which the vehicle forward visual confirmation device 10 is attached.

[0023] 2, the optical probe devices 20 are provided on both the left and right sides of the front end of the host vehicle Va. Hereinafter, the optical probe device 20 provided on the right side of the front end of the host vehicle Va (the right side as one faces the front of the vehicle) will be referred to as the right optical probe device 20R. Also, the optical probe device 20 provided on the left side of the front end of the host vehicle Va (the left side as one faces the front of the vehicle) will be referred to as the left optical probe device 20L.

[0024] 3 and 4 show the right measurement target area A at a reference distance, which will be described later. ２０Ｒ and left measurement target area A ２０Ｌ This is an example.

[0025] The right optical probe device 20R is configured to measure a right measurement area A set in front of the host vehicle Va. ２０Ｒ The left optical probe device 20L is configured to irradiate a group of laser beams (group of infrared laser beams) that form a dot pattern in a left measurement target area A (see FIG. 3) with a pulse oscillation frequency (MHz) according to the measurement distance and with a short pulse width (ns to ps) that has a distance resolution of about 1 / 100 or less of the measurement distance. ２０Ｌ The right optical probe device 20R (see FIG. 3) is configured to irradiate a group of laser beams (group of infrared laser beams) that form a dot pattern on the right measurement target area A with a pulse oscillation frequency (MHz) according to the measurement distance and a short pulse width (ns to ps) that has a distance resolution of about 1 / 100 or less of the measurement distance. For example, if the pulse oscillation frequency is set to 1 MHz (period: 1 μs), distance measurement of a measurement distance of up to 150 m (300 m round trip) is possible. Furthermore, if the pulse width is set to 10 ns, the distance resolution can be set to 1.5 m (3 m round trip). Furthermore, if the pulse width is set to 1 ns, the distance resolution can be improved to 0.15 m. Here, ２０Ｒ ) and the left optical probe device 20L (left measurement target area A ２０Ｌ ) have a symmetrical configuration, the right optical probe device 20R (right measurement target area A ２０Ｒ ) will be explained.

[0026] Right measurement area A ２０Ｒ The right measurement area A has a trapezoidal shape whose vertical width increases from the center of the vehicle width direction of the host vehicle Va toward the right side in the vehicle width direction. Specifically, as shown in FIG. ２０Ｒ is a trapezoid surrounded by an upper side L1R, a lower side L2R, an inner perpendicular line L3R, and an outer perpendicular line L4R.

[0027] In FIG. 4, symbol AX ２０Ｒ The symbol AX represents the optical axis of the right optical probe device 20R. ２０Ｌ The symbol Wp represents the optical axis of the left optical probe device 20L. ２０Ｒand optical axis AX ２０Ｌ The symbol Cp1 represents the distance between the optical axes AX ２０Ｒ and optical axis AX ２０Ｌ and Cp2. The symbol Cp2 represents the center point (the center point in the width direction of the current lane) between the current lane and the right lane adjacent to the current lane. The vertical line V1-V1 represents a vertical line passing through the center point Cp1. The horizontal line H1-H1 represents a horizontal line passing through the center points Cp1 and Cp2. The vertical line V2-V2 represents a vertical line passing through the center point Cp2. The symbol P1t represents the upper end point set above the optical probe device height Hp with respect to the center point Cp1. The symbol P1b represents the lower end point set below the optical probe device height Hp with respect to the center point Cp1. The symbol P2t represents the upper end point set above the optical probe device height Hp x 2 with respect to the center point Cp2. The symbol P2b represents the lower end point set below the optical probe device height Hp x 2 with respect to the center point Cp2.

[0028] The upper side L1R is a straight line passing through the upper end point P1t and the upper end point P2t. The lower side L2R is a straight line passing through the lower end point P1b and the lower end point P2b. The inner perpendicular line L3R is a straight line passing through the optical axis AX of the left optical probe device 20L. ２０Ｌ The outer perpendicular line L4R is a perpendicular line passing through the roadside of the right lane adjacent to the own lane.

[0029] Right measurement area A ２０Ｒ The dot density of the dot pattern formed in the right measurement area A is set to be high at the center in the vehicle width direction and to be low toward the right in the vehicle width direction. ２０Ｒ The dot spacing of the dot pattern formed is approximately 10 cm in the vertical and horizontal directions relative to the center point Cp1, and approximately 20 cm in the vertical and horizontal directions relative to the center point Cp2.

[0030] On the other hand, the left measurement target area A ２０Ｌ is the right measurement target area A ２０Ｒ That is, the left measurement target area A ２０Ｌ The left measurement area A has a trapezoidal shape whose vertical width increases from the center of the vehicle width direction of the host vehicle Va toward the left side in the vehicle width direction. Specifically, as shown in FIG. ２０Ｌis a trapezoid surrounded by an upper side L1L, a lower side L2L, an inner perpendicular line L3L, and an outer perpendicular line L4L.

[0031] Left measurement area A ２０Ｌ The dot density of the dot pattern formed in the left measurement area A is set so that it is higher at the center in the vehicle width direction and becomes lower toward the left side in the vehicle width direction. ２０Ｌ The dot spacing of the dot pattern formed is approximately 10 cm in the vertical and horizontal directions from a center point similar to the center point Cp1, and approximately 20 cm in the vertical and horizontal directions from a center point similar to the center point Cp2.

[0032] As shown in FIG. 4, the right measurement target area A ２０Ｒ and left measurement target area A ２０Ｌ are arranged symmetrically on the left and right, and at least partially overlap each other in the horizontal direction in front of the host vehicle Va. ２０Ｒ and left measurement target area A ２０Ｌ The right measurement area A covers the current lane and the lanes adjacent to the current lane on both the left and right sides. ２０Ｒ and left measurement target area A ２０Ｌ The overlapping area of ２０Ｒ＋２０Ｌ In this way, the overlapping area A ２０Ｒ＋２０Ｌ By providing the distance information, it becomes possible to dimerize the distance information as will be described later.

[0033] Right measurement area A ２０Ｒ The dots of the dot pattern formed in the left measurement target area A ２０Ｌ The dots of the dot pattern formed in the overlapping area A ２０Ｒ＋２０Ｌ are superimposed on each other in

[0034] In this way, the overlapping area A ２０Ｌ＋２０Ｒ The dot density is set high, which makes it easy to form a distance image of a preceding vehicle in the vehicle's own lane. It also makes it easy to measure the distance to a preceding vehicle that is farther away than the reference distance.

[0035] 5 and 6 show examples of the reference distance.

[0036] As shown in FIG. 5, the right measurement target area A ２０Ｒ and left measurement target area A２０Ｌ are set as the first reference distance, the second reference distance, and the third reference distance, respectively. In Fig. 5, the first reference distance is 40 m, which corresponds to the inter-vehicle distance at a vehicle speed of 55 km / h, the second reference distance is 80 m, which corresponds to the inter-vehicle distance at a vehicle speed of 85 km / h, and the third reference distance is 120 m, which corresponds to the inter-vehicle distance at a vehicle speed of 110 km / h.

[0037] As described above, the right measurement target area A is set at each of the first reference distance, the second reference distance, and the third reference distance. ２０Ｒ and left measurement target area A ２０Ｌ By setting the above, it is possible to easily detect a vehicle ahead of the host vehicle Va.

[0038] Next, a description will be given of a configuration example of the optical probe device 20. Below, a configuration example of the right optical probe device 20R will be described as a representative.

[0039] FIG. 7A is a schematic diagram of the right optical probe device 20R, and FIG. 7B is a cross-sectional view taken along line VIIB-VIIB of FIG. 7A.

[0040] 7A and 7B , the right optical probe device 20R includes a light emitting element 21, a correction lens 22, a mounting substrate 23 on which the light emitting element 21 is attached, and an oscillator circuit 24. These components are housed in a housing 25, and a light exit window 26 is provided in part of the housing 25, through which light emitted from the light emitting element 21 and transmitted through the correction lens 22 passes. The right optical probe device 20R is also connected to a control device 40 by a signal line 27.

[0041] The light-emitting element 21 includes a semiconductor laser that emits a wavelength (e.g., 905 nm, 940 nm, or 1450 nm) that generates a solar blind, and a diffractive optical element (DOE) that converts the light emitted from the semiconductor laser into a predetermined dot light pattern. The semiconductor laser is, for example, a vertical cavity surface emitting laser (VCSEL) with an emitter that emits multiple laser beams (24 × 64). The diffractive optical element is, for example, a DOE that is configured with a multi-bend cell array and multiply branches the laser beam emitted from the VCSEL emitter. Note that the semiconductor laser is not limited to a VCSEL, and may also be a stripe laser diode (LD) or a photonic crystal surface emitting laser (PCSEL). Furthermore, the dot light pattern may be formed using a rotating mirror (e.g., a MEMS mirror, a galvanometer mirror, or a polygon mirror) instead of a diffractive optical element.

[0042] The correction lens 22 diffuses (concave lens) and condenses (convex lens) the dot light beam pattern emitted from the light emitting element 21 so that it conforms to the shape of the irradiation area set for each reference distance.

[0043] The oscillator circuit 24 receives a control signal from the control device 40 and turns on or off the light emitting element 21 in a predetermined pattern (pulse oscillation).

[0044] The light exit window 26 has a filter function of transmitting light emitted from the light emitting element 21 and preventing external light from entering.

[0045] The right optical probe device 20R includes a plurality of light-emitting elements 21 corresponding to a plurality of measurement distances (first reference distance to third reference distance). Specifically, the right optical probe device 20R includes a right measurement target area A set at the first reference distance. ２０Ｒ a combination of a light emitting element 21 and a correction lens 22 that emits a group of laser beams that form a dot pattern in a right measurement area A set at a second reference distance; ２０Ｒ a combination of a light emitting element 21 and a correction lens 22 that emits a group of laser beams that form a dot pattern in the right measurement area A set at a third reference distance;２０Ｒ The optical element 20 includes a light emitting element 21 for emitting a group of laser beams that form a dot pattern on the optical element 20, and a correction lens 22.

[0046] The right optical probe device 20R switches the light emitting element 21 among the plurality of light emitting elements 21 to the light emitting element 21 corresponding to the vehicle speed of the host vehicle Va, and detects the right measurement target area A by the light emitting element 21 selected. ２０Ｒ The vehicle speed of the host vehicle Va may be provided by the driving assistance device 60 or obtained from a vehicle speed sensor (not shown) attached to the host vehicle Va, for example.

[0047] For example, when the vehicle speed of the host vehicle Va is 55 km / h, the right optical probe device 20R switches to the light emitting element 21 corresponding to the first reference distance, and the right measurement target area A set at the first reference distance is detected by the switched light emitting element 21. ２０Ｒ On the other hand, when the vehicle speed of the host vehicle Va is 85 km / h, the right optical probe device 20R switches to the light emitting element 21 corresponding to the second reference distance, and the light emitting element 21 illuminates the right measurement target area A set at the second reference distance. ２０Ｒ When the vehicle speed of the host vehicle Va is 110 km / h, the right optical probe device 20R switches to the light emitting element 21 corresponding to the third reference distance, and the light emitting element 21 thus switched illuminates the right measurement target area A set at the third reference distance. ２０Ｒ A group of laser beams that form a dot pattern is irradiated onto the substrate.

[0048] Similarly, the left optical probe device 20L includes a plurality of light-emitting elements 21 corresponding to a plurality of measurement distances (first reference distance to third reference distance). Specifically, the left optical probe device 20L includes a left measurement target area A set at the first reference distance. ２０Ｌ a combination of a light emitting element 21 and a correction lens 22 that emits a group of laser beams that form a dot pattern in a left measurement target area A set at a second reference distance; ２０Ｌ a combination of a light emitting element 21 and a correction lens 22 that emits a group of laser beams that form a dot pattern in the left measurement target area A set at a third reference distance;２０Ｌ The optical element 20 includes a light emitting element 21 for emitting a group of laser beams that form a dot pattern on the optical element 20, and a correction lens 22.

[0049] The left optical probe device 20L switches the light emitting element 21 among the plurality of light emitting elements 21 to the light emitting element 21 corresponding to the vehicle speed of the host vehicle Va, and detects the left measurement target area A by the light emitting element 21 selected. ２０Ｌ A group of laser beams that form a dot pattern is irradiated onto the substrate.

[0050] For example, when the vehicle speed of the host vehicle Va is 55 km / h, the left optical probe device 20L switches to the light emitting element 21 corresponding to the first reference distance, and the left measurement target area A set at the first reference distance is detected by the switched light emitting element 21. ２０Ｌ On the other hand, when the vehicle speed of the host vehicle Va is 85 km / h, the left optical probe device 20L switches to the light-emitting element 21 corresponding to the second reference distance, and the switched light-emitting element 21 illuminates the left measurement target area A set at the second reference distance. ２０Ｌ When the vehicle speed of the host vehicle Va is 110 km / h, the left optical probe device 20L switches to the light-emitting element 21 corresponding to the third reference distance, and the switched light-emitting element 21 illuminates the left measurement target area A set at the third reference distance. ２０Ｌ A group of laser beams that form a dot pattern is irradiated onto the substrate.

[0051] The right optical probe device 20R having the above configuration is disposed, for example, in the lamp chamber S1 of the vehicle lamp 50R mounted on the right side of the front end of the vehicle (the right side as one faces the front of the vehicle). Similarly, the left optical probe device 20L having the above configuration is disposed, for example, in the lamp chamber S1 of the vehicle lamp 50L mounted on the left side of the front end of the vehicle (the left side as one faces the front of the vehicle).

[0052] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG.

[0053] As shown in Fig. 8, the vehicle lamp 50R includes a bracket 52 to which a lamp unit 51 (semiconductor light emitting element 51a, reflecting surface 51b, projection lens 51c, and movable shade 51d) is attached, and an optical axis adjustment mechanism 53 (e.g., an aiming screw) that adjusts the optical axis of the lamp unit 51 by tilting the bracket 52. The lamp unit 51 and the optical axis adjustment mechanism 53 are disposed in a lamp chamber S1 formed between an outer lens 54 and a housing 55 attached thereto. In Fig. 8, reference numeral 56 denotes an extension.

[0054] The right optical probe device 20R is attached to the bracket 52 to which the lamp unit 51 is attached and is disposed in the lamp chamber S1 of the vehicle lamp 50R (see FIG. 8 ). Similarly, the left optical probe device 20L is attached to the bracket 52 to which the lamp unit 51 is attached and is disposed in the lamp chamber S1 of the vehicle lamp 50L. In this way, by attaching the right optical probe device 20R (and the left optical probe device 20L) to the bracket 52 that is tilted by the optical axis adjustment mechanism 53, it is possible to adjust the optical axis of the lamp unit 51 by the optical axis adjustment mechanism 53 and also to adjust the deviation of the laser beam groups irradiated from the right optical probe device 20R (and the left optical probe device 20L). Note that the right optical probe device 20R (and the left optical probe device 20L) does not necessarily have to be disposed in the lamp chamber S1 of the vehicle lamp 50, but may be disposed in an appropriate location such as the bumper, grille, side mirror, or front window of the host vehicle Va. In this case, by electrically connecting the light source unit 51 to the optical axis adjusting mechanism 53, it is possible to adjust the deviation of the laser beam group in the same way as when the light source unit 51 is attached to the bracket 52.

[0055] Next, the detection camera device 30 will be described.

[0056] The detection camera device 30 is configured to receive the return light emitted from the optical probe device 20 and reflected by the object present in the measurement target area, and generate a primary distance image in which the pixel values ​​are distance values. As shown in Figure 2, the detection camera device 30 is installed in the center of the vehicle interior in the vehicle width direction of the host vehicle Va. The detection camera device 30 captures an image of the area ahead of the host vehicle Va through the front window (wiper sweep area). As a result, an overlapping area A ahead of the vehicle center line is captured. ２０Ｒ＋２０Ｌ can be placed in the center of the field of view, improving the accuracy of distance measurement of the vehicle ahead.

[0057] FIG. 9A is a schematic diagram of the detection camera device 30, and FIG. 9B is a cross-sectional view taken along line IXB-IXB of FIG. 9A.

[0058] 9A and 9B, the detection camera device 30 includes an image sensor 31, a light receiving lens 32, a mounting board 33 on which the image sensor 31 is mounted, and a receiving circuit 34. These components are housed in a housing 35, and a light receiving window 36 is provided in part of the housing 35, through which light emitted from the optical probe device 20 and reflected from the object to be detected passes. The detection camera device 30 is also connected to a control device 40 by a signal line 37.

[0059] The imaging element 31 is a single photocounting imaging element (SPAD: Single Photon Avalanche Diode) that can measure the time of flight (direct ToF) of light emitted from the optical probe device 20. The imaging element 31 has a pixel count (10 (597 × 168) megapixels to 3 million pixels) that can resolve a distant detection target. A charge distribution type imaging element that detects a phase shift of the optical probe device 20 (indirect ToF) to obtain the distance to the detection target may also be used.

[0060] The light receiving lens 32 is positioned in the right measurement area A ２０Ｒ and left measurement target area A ２０Ｌ The lens adjusts the angle of view so that the object to be detected in the right measurement area A can be resolved on the light receiving surface of the image sensor 31. ２０Ｒ and left measurement target area A ２０Ｌ is set to 0.3 to 0.7 times on the image pickup element 31.

[0061] The receiving circuit 34 receives a control signal from the control device 40, performs imaging, and outputs the captured image (distance image).

[0062] The light receiving window 36 functions as a bandpass filter that selectively transmits only the light emitted from the optical probe device 20 .

[0063] The detection camera device 30 includes a plurality of image sensors 31 corresponding to a plurality of measurement distances (first reference distance to third reference distance). Specifically, the detection camera device 30 includes a combination of a light receiving lens 32 and an image sensor 31 corresponding to the first reference distance, a combination of a light receiving lens 32 and an image sensor 31 corresponding to the second reference distance, and a combination of a light receiving lens 32 and an image sensor 31 corresponding to the third reference distance.

[0064] The detection camera device 30 switches the imaging element 31 among the plurality of imaging elements 31 to the imaging element 31 corresponding to the vehicle speed of the host vehicle Va, and the imaging element 31 selected captures the right measurement target area A set at the first reference distance. ２０Ｒ or left measurement area A ２０Ｌ The system captures the returned light reflected from an object present in the image, and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values.

[0065] For example, when the vehicle speed of the host vehicle Va is 55 km / h, the detection camera device 30 switches to the image sensor 31 corresponding to the first reference distance, and the switched image sensor 31 captures the right measurement target area A set at the first reference distance. ２０Ｒ or left measurement area A ２０Ｌ The detection camera device 30 captures the reflected light from the object present in the right measurement target area A and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values. On the other hand, when the vehicle speed of the subject vehicle Va is 85 km / h, the detection camera device 30 switches to the image sensor 31 corresponding to the second reference distance, and the switched image sensor 31 captures the reflected light from the object present in the right measurement target area A and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values. ２０Ｒ or left measurement area A ２０ＬThe detection camera device 30 captures the reflected light from the object present in the right measurement target area A and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values. When the vehicle speed of the subject vehicle Va is 110 km / h, the detection camera device 30 switches to the image sensor 31 corresponding to the third reference distance, and the switched image sensor 31 captures the reflected light from the object present in the right measurement target area A and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values. ２０Ｒ or left measurement area A ２０Ｌ The system captures the returned light reflected from an object present in the image, and generates a right distance image or a left distance image as a primary distance image in which pixel values ​​are distance values.

[0066] As described above, by preparing an optical probe device 20 (image sensor 31) and a detection camera device 30 for each reference distance, it is possible to prevent a decrease in distant resolution when the nearby distance is used as the reference distance, and also to prevent a narrowing of the nearby field of view when the distant distance is used as the reference distance, thereby enabling accurate road information to be obtained at all times.

[0067] Next, the control device 40 (control ECU) will be described.

[0068] The control device 40 (control ECU: Electronic Control Unit) includes, for example, a processor (not shown), a storage unit 41, and a memory 42.

[0069] The processor is, for example, a CPU (Central Processing Unit). There may be one or more processors. The processor executes a predetermined program (not shown) loaded from a storage unit 41 (e.g., ROM) into a memory 42 (e.g., RAM) to function as an imaging unit 43, an object distance calculation unit 44, a dot density detection unit 45, a secondary distance image generation unit 46, and a communication unit 47. Some or all of these may be realized by hardware.

[0070] The imaging unit 43 controls the right optical probe device 20R, the left optical probe device 20L, and the detection camera device 30 to capture a right distance image and a left distance image. For example, in response to a command from the upper driving assistance device 60, the imaging unit 43 turns on the right optical probe device 20R and the left optical probe device 20L at a predetermined light emission timing and causes the detection camera device 30 to capture an image at a predetermined timing.

[0071] The object distance calculation unit 44 calculates the right measurement object area A ２０Ｒ and left measurement target area A ２０Ｌ Overlap area A with ２０Ｒ＋２０Ｌ Calculate the distance to an object located in the area.

[0072] The dot density detection unit 45 detects the dot density in the right measurement area A. ２０Ｒ and left measurement area A ２０Ｌ Overlap area A with ２０Ｒ＋２０Ｌ Detect the dot density within the

[0073] The secondary distance image generation unit 46 generates a secondary distance image to be transmitted to the higher-level driving assistance device 60 based on the right distance image and left distance image, which are the primary distance images transmitted from the detection camera device 30. The secondary distance image generated by the secondary distance image generation unit 46 is, for example, a composite distance image obtained by combining the right distance image and the left distance image.

[0074] The communication unit 47 transmits the secondary distance image generated by the secondary distance image generation unit 46 to the higher-level driving assistance device 60 as response information to the command.

[0075] Next, an example of the operation of the device 10 for visually confirming a forward direction of a vehicle having the above configuration will be described.

[0076] FIG. 10 is a flowchart of an example of the operation of the device 10 for visually confirming a forward direction of a vehicle.

[0077] First, an imaging process is executed (step S10).

[0078] 11 is a flowchart showing an example of the image capturing process. The following process is mainly executed by the image capturing unit 43.

[0079] First, the right optical probe device 20R switches the light emitting element 21 among the plurality of light emitting elements 21 to the light emitting element 21 corresponding to the vehicle speed of the host vehicle Va (step S101), and detects the right measurement target area A by the switched light emitting element 21. ２０Ｒ For example, when the vehicle speed of the host vehicle Va is 55 km / h, the right optical probe device 20R switches to the light-emitting element 21 corresponding to the first reference distance, and emits a group of laser beams that form a dot pattern in the right measurement target area A set at the first reference distance by the switched light-emitting element 21. ２０ＲOn the other hand, when the vehicle speed of the host vehicle Va is 85 km / h, the right optical probe device 20R switches to the light emitting element 21 corresponding to the second reference distance, and the light emitting element 21 illuminates the right measurement target area A set at the second reference distance. ２０Ｒ When the vehicle speed of the host vehicle Va is 110 km / h, the right optical probe device 20R switches to the light emitting element 21 corresponding to the third reference distance, and the light emitting element 21 thus switched illuminates the right measurement target area A set at the third reference distance. ２０Ｒ A group of laser beams that form a dot pattern is irradiated onto the substrate.

[0080] Next, the detection camera device 30 switches the imaging element 31 among the plurality of imaging elements 31 to the imaging element 31 that corresponds to the vehicle speed of the host vehicle Va (step S103), and the imaging element 31 that has been switched to captures the right measurement target area A ２０Ｒ The control device 40 then captures the reflected light from the object (step S104), and generates a right distance image as a primary distance image whose pixel values ​​are distance values ​​(step S105). The captured (generated) right distance image is then sent to the control device 40.

[0081] Next, the left optical probe device 20L switches to the light emitting element 21 corresponding to the vehicle speed of the host vehicle Va among the plurality of light emitting elements 21 (step S106), and detects the left measurement target area A ２０Ｌ For example, when the vehicle speed of the host vehicle Va is 55 km / h, the left optical probe device 20L switches to the light-emitting element 21 corresponding to the first reference distance, and emits a group of laser beams that form a dot pattern in the left measurement target area A set at the first reference distance by the switched light-emitting element 21. ２０Ｌ On the other hand, when the vehicle speed of the host vehicle Va is 85 km / h, the left optical probe device 20L switches to the light-emitting element 21 corresponding to the second reference distance, and the switched light-emitting element 21 illuminates the left measurement target area A set at the second reference distance. ２０ＬWhen the vehicle speed of the host vehicle Va is 110 km / h, the left optical probe device 20L switches to the light-emitting element 21 corresponding to the third reference distance, and the switched light-emitting element 21 illuminates the left measurement target area A set at the third reference distance. ２０Ｌ A group of laser beams that form a dot pattern is irradiated onto the substrate.

[0082] Next, the detection camera device 30 switches to the imaging element 31 corresponding to the vehicle speed of the host vehicle Va from among the plurality of imaging elements 31 (step S108), and acquires the left measurement target area A ２０Ｌ The controller 40 then captures the reflected light from the object (step S109) and generates a right distance image as a primary distance image whose pixel values ​​are distance values ​​(step S110). The captured (generated) right distance image is then sent to the controller 40.

[0083] Here, the overlapping area A ２０Ｌ＋２０Ｒ If an object (e.g., a preceding vehicle) is present in the right direction, two distances to the object are obtained: one based on the right distance image and the other based on the left distance image. In other words, distance information can be dimerized.

[0084] Next, returning to FIG. 10, a secondary distance image generation process is executed (step S20).

[0085] 12 is a flowchart showing an example of the secondary distance image generation process. The following process is mainly executed by secondary distance image generation unit 46.

[0086] First, the right distance image transmitted in step S105 and the left distance image transmitted in step S110 are acquired (step S201).

[0087] Next, a composite distance image (an example of a secondary distance image of the present disclosure) is generated by combining the right distance image and the left distance image acquired in step S201 (step S202).

[0088] Next, the synthetic distance image generated in step S202 is transmitted to the higher-level driving assistance device 60 (step S203).

[0089] Next, returning to FIG. 10, the object distance calculation process is executed (step S30).

[0090] 13 is a flowchart showing an example of the object distance calculation process. The following process is mainly executed by the object distance calculation unit 44.

[0091] First, the right measurement area A ２０Ｒ the inner perpendicular line L3R (see FIG. 4) and the left measurement target area A ２０Ｌ Detect the inner perpendicular lines L3L (see FIG. 4) of the right measurement target area A (step S301). ２０Ｒ The inner perpendicular line L3R of the left measurement target area A can be detected, for example, based on the right distance image transmitted in step S105 (or the composite distance image generated in step S202). ２０Ｌ The inner perpendicular line L3L can be detected, for example, based on the left distance image transmitted in step S110 (or the composite distance image generated in step S202).

[0092] Next, the distance Wf between the inner perpendicular lines detected in step S301 (hereinafter also referred to as the inner boundary distance Wf) is calculated (step S302).

[0093] Next, the distance to the object Lc = (Wf / 2) / tan(θi) is calculated using the distance Wf between the inner perpendicular lines calculated in step S302 and the known angle θi (step S22). Each element in this equation can be illustrated as shown in FIG. 14. By calculating the inner boundary line distance Wf in this manner, it becomes possible to trimerize the distance information. FIG. 14 is a diagram showing each element in the equation for calculating the distance Lc to the object.

[0094] When an object (for example, a preceding vehicle) is present at a distance greater than the reference distance, the inner boundary line interval Wf is ２０Ｒ and optical axis AX ２０Ｌ On the other hand, when an object (for example, a preceding vehicle) is present at the reference distance, the inner boundary distance Wf is greater than the optical axis distance Wp between the optical axes AX and AX. ２０Ｒ and optical axis AX ２０Ｌ When an object (for example, a preceding vehicle) is present closer than the reference distance, the inner boundary distance Wf is equal to the distance Wp between the optical axes AX２０Ｒ and optical axis AX ２０Ｌ The distance Wp between the optical axes of the two lenses is smaller than the distance Wp between the optical axes of the two lenses.

[0095] Next, returning to FIG. 10, the dot density detection process is executed (step S40).

[0096] Fig. 15 is an example flowchart of the dot density detection process. Fig. 16(a) to (c) are diagrams showing how the dot density changes periodically. The following process is mainly executed by the dot density detection unit 45.

[0097] First, overlapping area A ２０Ｒ＋２０Ｌ (See FIG. 4) (Step S401). ２０Ｒ＋２０Ｌ The dot density within can be detected, for example, based on the synthetic distance image generated in step S202.

[0098] When an object (for example, a preceding vehicle) is present at the reference distance, the right measurement object area A ２０Ｒ Dots in and left measurement area A ２０Ｌ The dots in the overlapping area A overlap with each other. ２０Ｒ＋２０Ｌ The dot density in the area decreases (see FIG. 16(a)).

[0099] On the other hand, when the object (e.g., a preceding vehicle) approaches closer than the reference distance, the dot density temporarily increases (see FIG. 16(b)), and then decreases as the object approaches further (see FIG. 16(c)). In this way, the dot density oscillates. This phenomenon also occurs when the object (e.g., a preceding vehicle) moves away from the reference distance.

[0100] Next, the change period of the dot density is calculated (detected) (step S402), and the approach speed (or separation speed) to the object is estimated (step S403). This can be calculated, for example, based on the results of executing the process of step S401 multiple times. In this way, the right measurement target area A ２０Ｒ and left measurement target area A ２０Ｌ Overlapping area A ２０Ｒ＋２０Ｌ The dot density of the image oscillates periodically as the preceding vehicle approaches, making it possible to quaternize the distance information.

[0101] As described above, according to this embodiment, it is possible to obtain a large amount of distance information and provide highly reliable (accurate) distance information to the higher-level device (driving assistance device 60). Note that, for the sake of simplicity, the above description has been given based on the first to third reference distances corresponding to the vehicle speed of the host vehicle Va, but when the vehicle speed of the host vehicle Va is other than the aforementioned vehicle speeds, the same function can be achieved by selecting a reference distance corresponding to a closer vehicle speed.

[0102] As described above, according to the first embodiment, it is possible to provide the device 10 for visually confirming a forward direction of a vehicle, which is capable of preventing erroneous detection of an object such as a nearby vehicle.

[0103] This is the right measurement target area A ２０Ｒ and left measurement target area A ２０Ｌ are arranged symmetrically on the left and right, and overlap at least partially in front of the vehicle Va in the horizontal direction. Therefore, if an object (e.g., a preceding vehicle) is present in this overlapping area, two distances to the object are obtained: a distance based on the right distance image and a distance based on the left distance image.

[0104] Next, a modified example will be described.

[0105] In the first embodiment, the right measurement target area A ２０Ｒ A trapezoidal region whose vertical width increases from the center of the vehicle width direction of the host vehicle Va toward the right side in the vehicle width direction is used as the left measurement target region A ２０Ｌ In the above description, an example has been described in which a trapezoidal region whose width in the vertical direction increases from the center side in the vehicle width direction of the host vehicle Va toward the left side in the vehicle width direction is used as the trapezoidal region, but the present invention is not limited to this.

[0106] For example, as shown in FIG. 17, the right measurement target area A ２０Ｒ A rectangular area extending from the center of the vehicle width direction of the host vehicle Va to the right side in the vehicle width direction is used as the left measurement target area A ２０Ｌ Alternatively, a rectangular area extending from the center of the vehicle width direction of the host vehicle Va to the left side in the vehicle width direction may be used as the right measurement target area A. ２０Ｒ and left measurement target area A ２０Ｌ This is a modified example of

[0107] As shown in FIG. 18A, the light emitting element 21 (VCSEL / LD) of the optical probe device 20 is divided into a plurality of right measurement target areas A ２０Ｒ (or left measurement area A ２０Ｌ 18A shows a modified example of the light emitting element 21 of the optical probe device 20, and FIG. 18B shows a modified example of the light emitting element 21 of the right measurement target area A. ２０Ｒ and left measurement target area A ２０Ｌ This is a modified example of

[0108] For example, if it is desired to obtain accurate information about a preceding vehicle in the vehicle's own lane, the light output of light-emitting element 1A can be increased to increase the intensity of the probe light reflected from the preceding vehicle. Also, if information about adjacent vehicles (in adjacent lanes) is not required, the light-emitting elements (e.g., 1C to 1E) corresponding to the adjacent vehicles (in adjacent lanes) may be turned off.

[0109] Second Embodiment Next, a second embodiment will be described.

[0110] FIG. 19 is a schematic diagram of a vehicle forward visual confirmation device 10A according to the second embodiment.

[0111] 19 , the device 10A for visually confirming a forward direction of a vehicle differs from the device 10 for visually confirming a forward direction of a vehicle in that it further includes a first-stage processing unit 48, a processing code generating unit 49, and a transmission data generating unit 49A. Other than that, the device 10A has the same configuration as the device 10 for visually confirming a forward direction of a vehicle in the first embodiment. The following description will focus on the differences from the device 10 for visually confirming a forward direction of a vehicle in the first embodiment, and the same components as those in the device 10 for visually confirming a forward direction of a vehicle in the first embodiment will be denoted by the same reference numerals and will not be described as appropriate.

[0112] The first stage processing unit 48, the processing code generation unit 49, and the transmission data generation unit 49A are realized by a processor (not shown) executing a predetermined program (not shown) that is read from the storage unit 41 (e.g., ROM) to the memory 42 (e.g., RAM).

[0113] The first-stage processing unit 48 performs first-stage processing, including a predetermined recognition process, on the distance image. The distance images on which the first-stage processing unit 48 performs first-stage processing are, for example, a right distance image and a left distance image (an example of a primary distance image in the present disclosure). Alternatively, the distance image on which the first-stage processing unit 48 performs first-stage processing may be a composite distance image generated by the secondary distance image generation unit 46 (an example of a secondary distance image in the present disclosure).

[0114] The first-stage processing performed by the first-stage processing unit 48 includes, for example, noise light removal, pattern recognition, and processing code generation. ２０Ｒ the inner perpendicular line L3R (see FIG. 4) and the left measurement target area A ２０Ｌ 13 and the inner perpendicular line L3L (see FIG. 4) (step S301 in FIG. 13), and dot density detection processing (step S40 in FIG. 15).

[0115] Noise light removal is a process for removing noise light from the right and left distance images. Noise light exists both during the day (strong external light) and at night (when flashes of light are present). Therefore, noise removal is performed on the measurement distance image (primary distance image) generated by the detection camera device. For example, in ToF measurements, natural light noise is random over time, while the reflected light from the object is constant over time. Therefore, by superimposing distance measurement data, the noise component can be smoothed (background) and the target component can be amplified. This allows the background and target component to be separated and extracted. This noise light removal is achieved by performing a specified image processing (noise light removal processing) on ​​the right and left distance images. The specified image processing (noise light removal processing) may be a known noise light removal processing.

[0116] Pattern recognition is an example of a predetermined recognition process of the present disclosure, and is a process for recognizing specific patterns (e.g., lane markings, lane markings, preceding vehicles, inner perpendicular lines, dot density) in the right distance image and the left distance image. Recognition of lane markings, lane markings, and preceding vehicles is achieved by applying predetermined image processing (image recognition processing) to the right distance image and the left distance image. The predetermined image processing (image recognition processing) may be a known image recognition process. Meanwhile, recognition of inner perpendicular lines (detection of the interval Wf between inner perpendicular lines) is achieved by steps S301 and S302 in FIG. 13 .

[0117] The lane markings extend forward from the left and right sides of the host vehicle, parallel to the line of travel of the host vehicle. Therefore, recognition of lane markings is evaluated by narrowing down to the range where lane markings should be. Furthermore, recognition of a preceding vehicle is evaluated by narrowing down to the area ahead of the host vehicle's lane. Furthermore, when the host vehicle Va changes lanes, evaluation is evaluated by narrowing down to the area ahead of the virtual host vehicle's lane, which is sandwiched between virtual lane markings. Note that virtual lane markings are lane markings that can be drawn on the left and right of the host vehicle Va, with the host vehicle Va as the reference point.

[0118] The processing code generation is realized, for example, by a processing code generation unit 49. The processing code generation unit 49 executes a processing code generation process to generate a processing code representing the result of pattern recognition. Note that the processing code has a smaller data volume than a synthetic range image, which will be described later.

[0119] FIG. 20 shows an example of the processing code generation process.

[0120] As shown in FIG. 20, the processing code generation unit 49 determines whether or not predetermined conditions (out-of-range condition, transition state condition, valid condition) are met (steps S51, S52, S53), and if the conditions are met (step S51: YES, step S52: YES, step S53: YES), generates a processing code corresponding to the condition (step S53).

[0121] First, the out-of-range conditions will be described.

[0122] FIG. 21 shows an example of an out-of-range condition and a processing code that is generated when the out-of-range condition is met. The correspondence between the out-of-range condition and the processing code is stored in the storage unit 41. In FIG. 21, the "x", "▲", and "-" in the "(1) lane marking" column and the "(2) preceding vehicle" column, and the "N.D" in the "(3) boundary line distance (Wf)" column represent out-of-range conditions. When the out-of-range condition is met, a processing code (e.g., "O1" or "O2") is generated that indicates that lane markings or the like cannot be recognized. This processing code is a status code that is generated when the vehicle forward visibility device 10A cannot recognize lane markings.

[0123] Here, "virtual vehicle lane," "within reference distance," and "closest vehicle" in the "(2) Preceding vehicle" column indicate the range within which the presence or absence of a preceding vehicle is determined. Here, "virtual vehicle lane" refers to the virtual vehicle lane sandwiched between the aforementioned virtual lane markings. "Within reference distance" refers to within the "reference distance" of the optical probe device (light-emitting element 21) selected according to the vehicle speed of the subject vehicle Va. "Closest vehicle" refers to the closest vehicle within the virtual vehicle lane. In other words, if a preceding vehicle is present within the reference distance within the virtual vehicle lane, the presence or absence of a preceding vehicle is determined based on the closest vehicle. Note that if a lane marking can be recognized, the virtual lane marking is replaced.

[0124] The reasons for determining whether or not there is a preceding vehicle within the "reference distance" are as follows: First, the reference distance of the probe device is set to the safe inter-vehicle distance + α corresponding to the vehicle speed. In other words, a preceding vehicle within the safe inter-vehicle distance is a preceding vehicle requiring caution. Second, the measurement distance of dToF is finite. For example, when the frequency of the probe light emitted from the probe device is 1 MHz, the maximum measurement distance is 150 m (round-trip distance of 300 m). Also, if preceding vehicles are traveling in a line, shifted to the left or right, within the own lane, different preceding vehicles may be detected within the illumination range of the right probe device (e.g., a distant vehicle traveling on the right side) and the illumination range of the left probe device (e.g., a nearby vehicle traveling on the left side). In this case, the closest vehicle is the preceding vehicle requiring caution.

[0125] The out-of-range conditions will be explained in more detail below.

[0126] An "x" in the "(1) lane markings" column in FIG. 21 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not recognized," i.e., that the pattern recognition by the initial processing unit 48 was unable to recognize a lane marking or a marking within the lane. On the other hand, an "▲" in the "(1) lane markings" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "line shadow," i.e., that the pattern recognition by the initial processing unit 48 was able to recognize (measure) a lane marking or a line shadow of a lane marking or a marking within the lane. Furthermore, a "-" in the "(1) lane markings" column in FIG. 21 indicates that the recognition result of the pattern recognition by the initial processing unit 48 was "not evaluated."

[0127] Note that the "x," "▲," and "-" symbols to the right of "Right-side lane marking:," "Drawn in lane:," and "Left-side lane marking:" in the "Lane Marking" column in FIG. 21 each represent a single state. That is, the "Lane Marking" column shows three states. For example, the first state is "Right-side lane marking: x," "Drawn in lane: -," and "Left-side lane marking: x." Similarly, the second state is "Right-side lane marking: ▲," "Drawn in lane: -," and "Left-side lane marking: x," and the third state is "Right-side lane marking: x," "Drawn in lane: -," and "Left-side lane marking: ▲." That is, this condition is met if the result of pattern recognition by the initial processing unit 48 corresponds to one of the three states.

[0128] Furthermore, the "x" in the "(2) Preceding vehicle" column in Figure 21 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not recognized," i.e., that the preceding vehicle cannot be recognized as a result of the pattern recognition by the initial processing unit 48. Specifically, this is the case when the preceding vehicle is traveling at a distance greater than the measurement reference distance (farther than the safe inter-vehicle distance), or when there is no preceding vehicle at a distance in the own lane. On the other hand, the "△ (single quantification)" in the "(2) Preceding vehicle" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "one-sided distance measurement," i.e., the preceding vehicle was recognized (distance measurement) using one of the right distance image and the left distance image, but was not recognized (distance measurement) using the other (single quantification).

[0129] 21 indicates that the boundary line interval (Wf) cannot be recognized (detected) as a result of pattern recognition by the first-stage processing unit 48.

[0130] 21 to 23, "traffic lane markings" refer to white lines that demarcate the lane in which the host vehicle Va is traveling (the host lane). "Right-side lane markings" refer to lane markings on the right side of the host vehicle Va. "Left-side lane markings" refer to lane markings on the left side of the host vehicle Va. "Intra-lane markings" refer to markings on the road surface between the right-side lane markings and the left-side lane markings (for example, road markings for merging or branching roads). "Preceding vehicle" refers to a vehicle ahead of the host vehicle Va that is in the host vehicle's lane and within a reference distance. "Boundary line spacing (Wf)" refers to the spacing Wf between the inner perpendicular lines (see FIG. 4).

[0131] The processing codes ("O1", "O2") shown in the "Processing Code" column in Fig. 21 are examples of processing codes that are generated when the above out-of-range conditions are met (step S51: YES in Fig. 20). The factors that cause this processing code to be generated are as shown in the "Cause / Status" column in Fig. 21. The above describes the processing codes that are generated when the out-of-range conditions and out-of-range conditions are met, but the processing codes that are generated when the out-of-range conditions and out-of-range conditions are met are not limited to those shown in Fig. 21.

[0132] Next, the conditions for the transition state will be described.

[0133] FIG. 22 shows an example of a transition state condition and a processing code generated when the transition state condition is satisfied. The correspondence between the transition state condition and the processing code is stored in the storage unit 41. In FIG. 22, the "x," "▲," and "-" symbols in the "(1) lane boundary line" and "(2) preceding vehicle" columns and the "N.D." symbol in the "(3) boundary line distance (Wf)" column represent the transition state conditions. When the transition state conditions are satisfied, a processing code (e.g., "T1," "T2," "T3," or "T4") indicating that the host vehicle Va is in a transition state is generated. This processing code is a status code generated when the vehicle forward visual confirmation device 10A (1) recognizes a road marking or the like within the lane boundary line, (2) a vehicle in another lane enters the host vehicle lane area by merging or changing lanes, (3) the host vehicle Va crosses the lane boundary line while changing lanes, or (4) a vehicle appears ahead within the virtual lane boundary (virtual host vehicle lane area) while the host vehicle Va is changing lanes.

[0134] The conditions for the transition state will be explained in more detail below.

[0135] The "▲" in the "(1) Traffic Lane Marking" column in Fig. 22 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is a "line shadow," that is, the pattern recognition by the initial processing unit 48 indicates that a traffic lane marking or a line shadow drawn within the lane was detected and recognized (distance-measured). On the other hand, the "-" in the "(1) Traffic Lane Marking" column in Fig. 21 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not evaluated."

[0136] Furthermore, the "x" in the "(2) Preceding vehicle" column in Figure 22 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not recognized," i.e., that the preceding vehicle cannot be recognized as a result of the pattern recognition by the initial processing unit 48. Specifically, this is the case when the vehicle is traveling at a distance greater than the measurement reference distance (farther than the safe inter-vehicle distance), or when there is no preceding vehicle at a distance in the own lane. On the other hand, the "△ (single quantification)" in the "(2) Preceding vehicle" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "one-sided ranging," i.e., the preceding vehicle was recognized (ranged) using one of the right distance image and the left distance image, but was not recognized (ranged) using the other.

[0137] 22 indicates that the boundary line interval (Wf) cannot be recognized (detected) as a result of pattern recognition by the first-stage processing unit 48.

[0138] The processing codes ("T1", "T2", "T3", "T4") listed in the "Processing Code" column in Figure 22 are examples of processing codes that are generated when the above transition state conditions are met (step S52: YES in Figure 20). The factors that cause this processing code to be generated are as listed in the "Cause / Status" column in Figure 22. The above describes the transition state conditions and the processing codes that are generated when the transition state conditions are met, but the transition state conditions and the processing codes that are generated when the transition state conditions are met are not limited to those listed in Figure 22.

[0139] Next, the valid conditions will be explained.

[0140] FIG. 23 shows an example of a valid condition and a processing code generated when the valid condition is met. Here, "valid" means that the host vehicle Va can recognize the actual lane markings painted on the road surface and is traveling in the host vehicle's lane. In other words, it means that the host vehicle Va is in a state where it can recognize whether or not there is a preceding vehicle traveling at a distance in the host vehicle's lane. The correspondence between the valid condition and the processing code is stored in the storage unit 41. In FIG. 23, "x," "▲," and "-" in the "(1) lane markings" column and the "(2) preceding vehicle" column, and "N.D.", "invalid," and "valid value (triquantified)" in the "(3) boundary line distance (Wf)" column indicate a practically reliable state. When the valid condition is met, a processing code (e.g., "V1," "V2," "V3," or "V4") indicating that the distance measurement value of the preceding vehicle is valid is generated.

[0141] In FIG. 23 , “zero quantization” means that the device 10A for visualizing the forward direction of a vehicle cannot recognize the preceding vehicle. “Single quantization” means that the device 10A for visualizing the forward direction of a vehicle recognizes the shadow of the preceding vehicle and can measure the distance using a probe light on one side, i.e., can recognize (measure the distance to) the preceding vehicle based on the right distance image or the left distance image. “Dual quantization” means that the device 10A for visualizing the forward direction of a vehicle recognizes the shadow of the preceding vehicle and can measure the distance using probe light on both sides. In other words, it means that the device 10A for visualizing the forward direction of a vehicle recognizes (measure the distance to) the preceding vehicle based on the right distance image and can recognize (measure the distance to) the preceding vehicle based on the left distance image. “Triquantization” means that the device 10A for visualizing the forward direction of a vehicle recognizes the shadow of the preceding vehicle and can measure the distance using probe light on both sides, and the boundary line distance (Wf) is a reasonable approximation to the measured distance value (measured distance value by single quantization or double quantization).

[0142] The valid conditions will be explained in more detail below.

[0143] 23, an "x" in the "(1) lane markings" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not recognized," i.e., that a lane marking or a line drawn in the lane could not be recognized as a result of pattern recognition by the initial processing unit 48. On the other hand, a "▲" in the "(1) lane markings" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "line shadow," i.e., that a lane marking or a line shadow drawn in the lane was present as a result of pattern recognition by the initial processing unit 48 and was recognized (distance-measured).

[0144] 23 indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "not recognized," i.e., the initial processing unit 48 was unable to recognize the preceding vehicle as a result of the pattern recognition. On the other hand, a "△ (single quantification)" in the "(2) Preceding vehicle" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "single distance measurement," i.e., the preceding vehicle was recognized (distance measurement) using one of the right distance image and the left distance image, but was not recognized (distance measurement) using the other (single quantification). Furthermore, a "○ (double quantification)" in the "(1) Preceding vehicle" column indicates that the recognition result of the pattern recognition by the initial processing unit 48 is "double distance measurement," i.e., the distance measurement value from the right distance image (distance measurement value to the preceding vehicle) and the distance measurement value from the left distance image (distance measurement value to the preceding vehicle) match (double quantification).

[0145] 23 indicates that the boundary line interval (Wf) cannot be recognized (detected) as a result of pattern recognition by the initial processing unit 48. On the other hand, "invalid" in the "(3) boundary line interval (Wf)" column indicates that the boundary line interval (Wf) is not a valid approximation to the measured distance value. Furthermore, "valid value" in the "(3) boundary line interval (Wf)" column indicates that the boundary line interval (Wf) is a valid approximation to the measured distance value.

[0146] The processing codes ("V1," "V2," "V3," and "V4") shown in the "Processing Code" column in Figure 23 are examples of processing codes that are generated when the valid conditions are met (step S53: YES in Figure 20). The factors that cause this processing code to be generated are as shown in the "Cause / Status" column in Figure 23. The valid conditions and processing codes that are generated when the valid conditions are met have been described above, but the valid conditions and processing codes that are generated when the valid conditions are met are not limited to those shown in Figure 23.

[0147] As described above, the processing code generation unit 49 executes a processing code generation process for generating a processing code representing the result of pattern recognition. Specifically, the processing code generation unit 49 determines whether a predetermined out-of-range condition (see FIG. 21) is satisfied (see step S51 in FIG. 20). If the condition is satisfied (step S51: YES), the processing code generation unit 49 generates a processing code corresponding to the condition. Specifically, the processing code corresponding to the condition is read from the storage unit 41.

[0148] Similarly, the processing code generation unit 49 determines whether or not a transition state condition (see FIG. 22) is satisfied as a predetermined condition (see step S52 in FIG. 20), and if the condition is satisfied (step S52: YES), generates a processing code corresponding to the condition.

[0149] Similarly, the processing code generation unit 49 determines whether or not a valid condition (see FIG. 23) is satisfied as a predetermined condition (see step S53 in FIG. 20), and if the condition is satisfied (step S53: YES), generates a processing code corresponding to the condition.

[0150] The transmission data generation unit 49A generates transmission data (e.g., a packet) including the processing code generated by the processing code generation unit 49 and the composite distance image generated by the secondary distance image generation unit 46. Figure 24 is an example of transmission data (packet) including the processing code and the composite distance image.

[0151] As shown in FIG. 24, the transmission data includes a header DT1, a processing code DT2, basic information DT3, and a synthetic distance image DT4.

[0152] The header DT1 includes the address of the driving assistance device 60 (address on the in-vehicle network) of the destination.

[0153] The processing code DT2 is a processing code generated by the processing code generation unit 49. The driving assistance device 60 receives the processing code DT2 before the response information body (basic information DT3 and composite distance image DT4). This allows the driving assistance device 60 to determine how to handle the response information body before receiving it. That is, the driving assistance device 60 can select a processing operation early. In other words, the distance image "DT4" has a large data volume, which increases the communication time. However, if immediacy of situation assessment is important for the upper device (driving assistance device 60), the upper device (driving assistance device 60) can receive "DT4" and select the next processing by referring to "DT2," which has a smaller data volume than "DT4."

[0154] Furthermore, by referencing the processing code DT2, the driving assistance device 60 can determine the usefulness of the composite distance image DT4 without performing any processing on the composite distance image DT4. In other words, the driving assistance device 60 can quickly determine the usefulness of the composite distance image DT4, which is the sensing result. Therefore, the driving assistance device 60 can quickly perform various subsequent processes.

[0155] The basic information DT3 is basic information data for handling the processed distance image (synthetic distance image). The basic information DT3 includes, for example, the measurement time (e.g., the time when the optical probe devices 20R and 20L irradiated the probe light (laser beam group)), the received vehicle speed (the vehicle speed of the host vehicle Va transmitted by the driving assistance device 60 to the vehicle forward visual confirmation device 10A), and the reference distance (the reference distance set by the vehicle forward visual confirmation device 10A). The basic information DT3 may also include other information. For example, when narrowing the readout angle of view of the image sensor 31, the basic information DT3 may include information on the left, right, top, and bottom angles of view, the start pixel address, etc.

[0156] The composite distance image DT4 is data of a composite distance image (secondary distance image) generated by the secondary distance image generating unit 46.

[0157] The communication unit 47 transmits the transmission data generated by the transmission data generation unit 49A to the upper-level driving assistance device 60 (an example of another device of the present disclosure). For example, the data is transmitted to the upper-level driving assistance device 60 as response information to a command. Note that the processing code generated by the processing code generation unit 49 and the composite distance image generated by the secondary distance image generation unit 46 may be transmitted to the upper-level driving assistance device 60 in a mutually associated form, not necessarily in the form of a packet.

[0158] Next, an example of the operation of the device 10A for visually confirming a forward direction of a vehicle having the above configuration will be described.

[0159] FIG. 25 is a flowchart of an example of the operation of the device 10A for visually confirming a forward direction of a vehicle.

[0160] First, an image capturing process is executed (step S10). The image capturing process has already been described (see FIG. 11), so a description thereof will be omitted.

[0161] Next, the first stage processing is executed (step S60). This first stage processing is realized by the first stage processing unit 48. The first stage processing unit 48 executes the first stage processing including predetermined recognition processing (noise light removal, pattern recognition, processing code generation) on the right distance image and the left distance image captured in step S10. The first stage processing unit 48 also executes the first stage processing including predetermined recognition processing (noise light removal, pattern recognition, processing code generation) on the right measurement target area A. ２０Ｒ the inner perpendicular line L3R (see FIG. 4) and the left measurement target area A ２０Ｌ 13. In this case, the processing code generation unit 49 generates the processing code in step S60.

[0162] As shown in FIG. 20, the processing code generation unit 49 determines whether or not predetermined conditions (out-of-range condition, transition state condition, valid condition) are met (steps S51, S52, S53), and if the conditions are met (step S51: YES, step S52: YES, step S53: YES), generates a processing code corresponding to the condition (for example, processing code "O1" in FIG. 21) (step S53).

[0163] Next, a composite distance image (an example of the secondary distance image of the present disclosure) is generated by combining the right distance image and the left distance image that have been subjected to the initial processing in step S60 (step S61). This is realized, for example, by the secondary distance image generator 46.

[0164] Next, transmission data is created (step S62). This is realized by transmission data generation unit 49A. Transmission data generation unit 49A generates, as transmission data, a packet (see FIG. 24) including the processing code generated in step S60 and the composite distance image generated in step S62.

[0165] Next, the transmission data generated in step S62 is transmitted to the higher-level driving support device 60 (step S20A5). This is realized by the communication unit 47.

[0166] As described above, according to embodiment 2, a vehicle forward viewing device 10A can be provided that allows another device (e.g., a driving assistance device 60) to quickly determine the usefulness of a synthetic distance image, which is a sensing result.

[0167] This is because, in addition to the synthetic range image that is the sensing result, a processing code that indicates the usefulness of the sensing result is transmitted to another device (for example, the driving assistance device 60).

[0168] The numerical values ​​shown in the above embodiments are all examples, and it goes without saying that other appropriate numerical values ​​can be used.

[0169] The above-described embodiments are merely illustrative in all respects. The present invention should not be construed as being limited by the descriptions of the above-described embodiments. For example, by combining the light-emitting element 21 of the optical probe device 20 shown in FIG. 18A with a high-pixel imaging element 31 in the detection camera device 30, the light-emitting element 21 and imaging element 31 previously provided at the first to third reference distances can be integrated into a single pair. The detection camera device 30 can also be provided at the edge of the windshield (wiper sweep area). In this case, the same function as described above can be achieved by adding perspective correction to the captured image. Thus, the present invention can be embodied in various other forms without departing from its spirit or main features.

[0170] This application claims priority based on Japanese Patent Application No. 2023-158224, filed on September 22, 2023, the disclosure of which is incorporated herein in its entirety.

[0171] DESCRIPTION OF SYMBOLS 10, 10A... Vehicle forward visibility device 20... Optical probe device 20L... Left optical probe device 20R... Right optical probe device 21... Light emitting element 22... Correction lens 23... Mounting board 24... Oscillator circuit 25... Housing 26... Light output window 30... Detection camera device 31... Image pickup element 32... Light receiving lens 33... Mounting board 34... Receiving circuit 35... Housing 36... Light receiving window 40... Control device 41... Storage unit 42... Memory 43... Image pickup unit 44... Object distance calculation unit 45... Dot density detection unit 46... Secondary distance image generation unit 47... Communication unit 48... Initial processing unit 49... Processing code generation unit 49A... Transmission data generation unit 50, 50R... Vehicle lamp 51... Lamp unit 51a... Semiconductor light emitting element 51b... Reflecting surface 51c... Projection lens 51d... Movable shade 52: Bracket 53: Optical axis adjustment mechanism 54: Outer lens 55: Housing 60: Driving assistance device A ２０Ｌ …Left measurement area A ２０Ｒ …Right measurement area AX ２０Ｌ , AX ２０Ｒ ...optical axis Cp1, Cp2...center point H1-H1...horizontal line Hp...height of optical probe device L1L, L1R...upper edge L2L, L2R...lower edge L3L, L3R...inner perpendicular line L4L, L4R...outer perpendicular line Lc...distance P1b, P2b...lower end point P1t, P2t...upper end point S1...light chamber V1-V1...vertical line V2-V2...vertical line Va...own vehicle Wf...inner boundary line interval Wp...distance between optical axes θi...angle

Claims

1. A vehicle forward visibility device mounted on a vehicle, comprising: a right optical probe device provided on the right side of a front end of the vehicle and irradiating a group of laser beams that form a dot pattern in a right measurement target area set at a specified reference distance forward of the vehicle; a left optical probe device provided on the left side of the front end of the vehicle and irradiating a group of laser beams that form a dot pattern in a left measurement target area set at a specified reference distance forward of the vehicle; and a detection camera device that captures returned light irradiated from the right optical probe device and reflected by an object present in the right measurement target area, and generates a right distance image as a primary distance image in which pixel values ​​are distance values, and conversely, captures returned light irradiated from the left optical probe device and reflected by an object present in the left measurement target area, and generates a left distance image as a primary distance image in which pixel values ​​are distance values, wherein the right measurement target area and the left measurement target area are arranged symmetrically and at least partially overlap each other in front of the vehicle in the horizontal direction.

2. A vehicle forward visibility device as described in claim 1, wherein the outer shape of the right measurement target area is a trapezoid whose vertical width increases from the center in the vehicle width direction toward the right side in the vehicle width direction, and the outer shape of the left measurement target area is a trapezoid whose vertical width increases from the center in the vehicle width direction toward the left side in the vehicle width direction.

3. A vehicle forward visibility device as described in claim 2, wherein the dot density of the dot pattern formed in the right measurement target area is set to be higher toward the center in the vehicle width direction and lower toward the right side in the vehicle width direction, and the dot density of the dot pattern formed in the left measurement target area is set to be higher toward the center in the vehicle width direction and lower toward the left side in the vehicle width direction.

4. The vehicle forward visibility device according to claim 2, further comprising an object distance calculation unit that calculates the distance to an object present in an overlapping area between the right measurement target area and the left measurement target area based on the inner perpendicular distance between the inner perpendicular line of the right measurement target area and the inner perpendicular line of the left measurement target area.

5. The device for visually confirming a forward view of a vehicle according to claim 4, further comprising a dot density detection unit that detects a period of change in dot density within an overlapping area between the right measurement target area and the left measurement target area.

6. A vehicle forward visibility device as described in claim 1, further comprising: a bracket to which a lamp unit is attached; and an optical axis adjustment mechanism for adjusting the optical axis of the lamp unit by tilting the bracket, wherein the optical probe device is attached to the bracket.

7. The vehicle forward visibility device according to claim 1, further comprising a secondary distance image generating unit that generates a secondary distance image to be transmitted to another device based on the right distance image and the left distance image.

8. A vehicle forward visibility device as described in claim 1, wherein the right optical probe device and the left probe device each have a plurality of light-emitting elements corresponding to a plurality of measurement distances, and among the plurality of light-emitting elements, a light-emitting element is switched to one that corresponds to the vehicle speed of the vehicle; and the detection camera device has a plurality of image pickup elements corresponding to a plurality of measurement distances, and among the plurality of image pickup elements, a light-emitting element is switched to one that corresponds to the vehicle speed of the vehicle.

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