Vehicle front view device

Abstract

A vehicle front view device capable of preventing erroneous detection of an object such as a nearby vehicle is provided. A vehicle front view device (10) mounted on a vehicle (Va) includes: a right optical detection device that emits a laser beam forming a dot pattern in a right measurement target area provided at a predetermined reference distance in front of the vehicle; a left optical detection device that emits a laser beam forming a dot pattern in a left measurement target area disposed at a predetermined reference distance in front of the vehicle; and a detection camera device configured to capture an image of return light emitted from the right optical detection device and reflected by an object present in the right measurement target area, and generate a right distance image as a main distance image in which a pixel value is a distance value; and capturing an image of return light emitted from the left optical detection device and reflected by an object present in the left measurement target area, and generating a left distance image as a main distance image in which a pixel value is a distance value.

Description

Technical Field

[0001] This disclosure relates to a vehicle forward-looking device. Background Technology

[0002] Vehicle forward-looking devices that use LiDAR to sense objects (such as nearby vehicles) in the area in front of a vehicle are known (see, for example, Patent Document 1).

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-505 Summary of the Invention

[0006] Technical issues

[0007] However, the problem with the vehicle forward-looking device described in Patent Document 1 is that the mechanism for preventing false detection of objects such as nearby vehicles is unsatisfactory.

[0008] To address this problem, this disclosure provides a vehicle forward-looking device capable of preventing false detection of objects such as nearby vehicles.

[0009] Solution to the problem

[0010] The vehicle forward-looking device according to this disclosure is a vehicle forward-looking device installed on a vehicle, the vehicle forward-looking device comprising: a right optical detection device disposed in the right side of the front end portion of the vehicle and configured to emit a laser beam forming a dot pattern in a right measurement target area disposed at a predetermined reference distance in front of the vehicle; a left optical detection device disposed in the left side of the front end portion of the vehicle and configured to emit a laser beam forming a dot pattern in a left measurement target area disposed at the predetermined reference distance in front of the vehicle; and a detection camera device configured to capture an image of reflected light emitted from the right optical detection device and reflected by an object present in the right measurement target area, and generate a right distance image as a primary distance image in which pixel values ​​are distance values, and capture an image of reflected light emitted from the left optical detection device and reflected by an object present in the left measurement target area, and generate 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 a horizontal direction about the front of the vehicle.

[0011] This configuration can be used to provide a vehicle forward-looking device that can prevent false detection of objects such as nearby vehicles.

[0012] The reason is that the right and left measurement target areas are arranged symmetrically and at least partially overlap each other in the horizontal direction about the front of the vehicle (this vehicle). Therefore, if there is an object (e.g., a vehicle in front) in this overlapping area, two distances (i.e., the distance based on the right distance image and the distance based on the left distance image) can be obtained as the distance to the object.

[0013] Furthermore, in the aforementioned vehicle forward-looking device, the outline of the right measurement target area can have a trapezoidal shape, the width of which in the vertical direction becomes wider from the center side in the vehicle width direction toward the right side in the vehicle width direction, and the outline of the left measurement target area can have a trapezoidal shape, the width of which in the vertical direction becomes wider from the center side in the vehicle width direction toward the left side in the vehicle width direction.

[0014] Furthermore, in the aforementioned vehicle forward-looking device, the dot density of the dot pattern formed in the right measurement target area can be set high on the center side in the vehicle width direction and decrease towards the right side in the vehicle width direction, and the dot density of the dot pattern formed in the left measurement target area can be set high on the center side in the vehicle width direction and decrease towards the left side in the vehicle width direction.

[0015] In addition, the aforementioned vehicle forward-looking device may also include an object distance calculation unit configured to calculate the distance to an object existing in the overlapping area of ​​the right and left measurement target areas based on the distance between the inner vertical lines of the right measurement target area and the inner vertical lines of the left measurement target area.

[0016] In addition, the aforementioned vehicle forward-looking device may also include a dot density detection unit configured to detect the periodicity of dot density change in the overlapping area of ​​the right and left measurement target areas.

[0017] In addition, the aforementioned vehicle forward-looking device may also include: a bracket to which an illumination unit is attached; and an optical axis adjustment mechanism configured to adjust the optical axis of the illumination unit by tilting the bracket, and an optical detection device may be attached to the bracket.

[0018] In addition, the aforementioned vehicle forward-looking device may also include an auxiliary distance image generation unit, which is configured to generate an auxiliary distance image to be sent to different devices based on a right distance image and a left distance image.

[0019] Furthermore, in the aforementioned vehicle forward-looking device, each of the right optical detection device and the left optical detection device may include multiple light-emitting elements corresponding to multiple measurement distances, and the light-emitting element can be selected from the multiple light-emitting elements according to the vehicle speed. The detection camera device may include multiple imaging elements corresponding to multiple measurement distances, and the imaging element can be selected from the multiple imaging elements according to the vehicle speed.

[0020] Beneficial effects

[0021] According to this disclosure, a vehicle forward-looking device can be provided that can prevent false detection of objects such as nearby vehicles. Attached Figure Description

[0022] Figure 1 This is a schematic configuration diagram of the vehicle forward-looking device 10; Figure 2 It is a front view of the vehicle Va on which the vehicle forward-looking device 10 is installed; Figure 3 The target area A is measured on the right. 20R And left measurement target area A 20L Examples; Figure 4 The target area A is measured on the right. 20R And left measurement target area A 20L Examples; Figure 5 This is an example of a reference distance; Figure 6 This is an example of a reference distance; Figure 7A This is a schematic diagram of the right optical detection device 20R; Figure 7B It is along Figure 7A A cross-sectional view taken from line VIIB-VIIB in the diagram; Figure 8 It is along Figure 2 A cross-sectional view taken from line VIII-VIII in the diagram; Figure 9A This is a schematic configuration diagram of the detection camera device 30; Figure 9B It is along Figure 9A A cross-sectional view taken from line IXB-IXB in the diagram; Figure 10 This is a flowchart illustrating an operation example of the vehicle forward-looking device 10; Figure 11 Here is a flowchart example for image processing; Figure 12 This is an example of a flowchart for auxiliary distance image generation and processing; Figure 13This is a flowchart example of the object distance calculation process; Figure 14 It is a view that indicates the corresponding element in the formula used to obtain the distance Lc to the object; Figure 15 Here is a flowchart example of point density detection processing; Figure 16 (a) to Figure 16 (c) is a view showing the aspect in which the point density changes periodically; Figure 17 The target area A is measured on the right. 20R And left measurement target area A 20L Modified examples; Figure 18A This is a modified example of the light-emitting element 21 of the optical detection device 20; Figure 18B The target area A is measured on the right. 20R And left measurement target area A 20L Modified examples; Figure 19 This is a schematic configuration diagram of the vehicle forward-looking device 10A according to the second embodiment; Figure 20 This is an example of handling code generation processes; Figure 21 These are examples of out-of-range conditions and the processing code generated when out-of-range conditions are met; Figure 22 These are examples of transition conditions and the processing code generated when those conditions are met; Figure 23 These are examples of valid conditions and the processing code generated when the valid conditions are met; Figure 24 This includes examples of transmitted data (packets) that process the code and synthesize the distance image; and Figure 25 This is a flowchart illustrating an operation example of the vehicle forward-looking device 10A. Detailed Implementation

[0023] In the following description, a vehicle forward-looking device 10, as an embodiment of the present invention, will be described with reference to the accompanying drawings. Corresponding components in the corresponding drawings will be indicated by the same reference numerals, and redundant descriptions will be omitted.

[0024] <First Implementation Method>

[0025] Figure 1 This is a schematic configuration diagram of the vehicle forward-looking device 10 according to the first embodiment.

[0026] The vehicle forward-looking device 10 is primarily a forward information acquisition device that provides forward information to driver assistance devices when the vehicle is traveling at medium to high speeds (e.g., from 40 to 120 km / h) on suburban roads.

[0027] like Figure 1 As shown, the vehicle forward-looking device 10 includes optical detection devices 20 (right optical detection device 20R, left optical detection device 20L), detection camera device 30, control device 40, and driver assistance device 60. The optical detection devices 20 and the detection camera device 30 constitute a LiDAR device. The vehicle forward-looking device 10 is installed on a vehicle such as an automobile. In the following text, the vehicle equipped with the vehicle forward-looking device 10 will be referred to as this vehicle Va.

[0028] Figure 2 It is a front view of the vehicle Va on which the vehicle forward-looking device 10 is installed.

[0029] like Figure 2 As shown, optical detection devices 20 are provided on the left and right sides of the front end portion of the vehicle Va. In the following text, the optical detection device 20 provided on the right side (right side when facing forward) of the front end portion of the vehicle Va will be referred to as the right optical detection device 20R. Furthermore, the optical detection device 20 provided on the left side (left side when facing forward) of the front end portion of the vehicle Va will be referred to as the left optical detection device 20L.

[0030] Figure 3 and Figure 4 The right measurement target area A at the reference distance, which will be described later. 20R And left measurement target area A 20L Examples.

[0031] The right optical detection device 20R is configured to emit a laser beam (infrared laser beam) with a pulse oscillation frequency (MHz) based on the measurement distance and with a short pulse width (ns to ps) equal to or less than 1 / 100 of the measurement distance. This laser beam is positioned in the right measurement target area A located in front of the vehicle Va. 20R (See) Figure 3 A dot pattern is formed in the area. Similarly, the left optical detection device 20L is configured to emit a laser beam (infrared laser beam) having a pulse oscillation frequency (MHz) depending on the measurement distance and a short pulse width (ns to ps) with a distance resolution equal to or less than 1 / 100th of the measurement distance, which is positioned in the left measurement target area A ahead of the vehicle Va. 20L (See) Figure 3A dot pattern is formed in the target area. For example, if the pulse oscillation frequency is set to 1MHz (period: 1μs), distance measurement within a measurement distance of 150m (300m round trip) is possible. Furthermore, if the pulse width is set to 10ns, a distance resolution of 1.5m (3m round trip) can be achieved. Even further, if the pulse width is set to 1ns, the distance resolution can be improved to 0.15m. Here, the right optical detection device 20R (right measurement target area A) 20R ) and left optical detection device 20L (left measurement target area A) 20L The right optical detection device 20R (right measurement target area A) is symmetrically configured; therefore, in the following text, we will mainly refer to the right optical detection device 20R. 20R ) will be described as representative.

[0032] Right measurement target area A 20R It has a trapezoidal shape, the width of which in the vertical direction increases from the center side in the vehicle width direction toward the right side of the vehicle's width (Va). Specifically, as... Figure 4 As illustrated in the example, the right measurement target area A 20R It has a trapezoidal shape surrounded by an upper vertical line L1R, a lower vertical line L2R, an inner vertical line L3R, and an outer vertical line L4R.

[0033] exist Figure 4 In the figure, the reference AX is used. 20R This indicates the optical axis of the right optical detector 20R. Reference symbol AX 20L This indicates the optical axis of the left optical detector 20L. The reference symbol Wp indicates the optical axis AX. 20R With optical axis AX 20L The optical axis distance between them. Reference symbol Cp1 represents the optical axis AX. 20R With optical axis AX 20L The center point between the two lanes (the center point in the width direction of this lane). Reference symbol Cp2 indicates the center point in the width direction of the right lane adjacent to this lane. Vertical line V1-V1 indicates a vertical line passing through the center point Cp1. Horizontal line H1-H1 indicates a horizontal line passing through the center points Cp1 and Cp2. Vertical line V2-V2 indicates a vertical line passing through the center point Cp2. Reference numeral P1t indicates the upper endpoint of the optical detection device at height Hp located above the center point Cp1. Reference numeral P1b indicates the lower endpoint of the optical detection device at height Hp located below the center point Cp1. Reference numeral P2t indicates the upper endpoint of the optical detection device at height Hp×2 located above the center point Cp2. Reference numeral P2b indicates the lower endpoint of the optical detection device at height Hp×2 located below the center point Cp2.

[0034] The upper line L1R passes through the upper endpoints P1t and P2t. The lower line L2R passes through the lower endpoints P1b and P2b. The inner vertical line L3R passes through the optical axis AX of the left optical detection device 20L. 20L The outer vertical line L4R is a vertical line that crosses the roadside of the right lane adjacent to this lane.

[0035] Target area A is measured on the right. 20R The dot density of the dot pattern formed is set to be higher on the center side in the vehicle width direction and lower towards the right side in the vehicle width direction. Specifically, the target area A is measured on the right side. 20R The dot pattern formed in the middle has a dot spacing of approximately 10 cm in the vertical and horizontal directions about the center point Cp1, and approximately 20 cm in the vertical and horizontal directions about the center point Cp2.

[0036] On the other hand, the left measurement target area A 20L With the ability to measure target area A by horizontal reversal to the right 20R The resulting shape. In other words, the left measurement target area A. 20L It has a trapezoidal shape, the width of which in the vertical direction increases from the center side in the vehicle width direction toward the right side of the vehicle's width (Va). Specifically, as... Figure 4 As illustrated in the example, the left measurement target area A 20L It has a trapezoidal shape surrounded by an upper vertical line L1L, a lower vertical line L2L, an inner vertical line L3L, and an outer vertical line L4L.

[0037] Target area A on the left 20L The dot density of the dot pattern formed in the middle is set to be higher on the center side in the vehicle width direction and lower towards the left side in the vehicle width direction. Specifically, in the left measurement target area A 20L The dot spacing of the dot pattern formed in the middle is approximately 10 cm in both the vertical and horizontal directions with respect to a center point similar to center point Cp1, and approximately 20 cm in both the vertical and horizontal directions with respect to a center point similar to center point Cp2.

[0038] like Figure 4 As shown, the target measurement area A on the right. 20R And left measurement target area A 20L The objects are symmetrically arranged and at least partially overlap each other in the horizontal direction about the front of the vehicle Va. Specifically, the right measurement target area A... 20R And left measurement target area A 20L Covers this lane as well as the adjacent left and right lanes. In the following text, the right measurement target area A... 20R With left measurement target area A20L The overlapping area will be referred to as overlapping area A. 20R+20L By providing such an overlapping region A 20R+20L This makes it possible to quantify distance information twice, as will be described later.

[0039] Target area A on the right 20R The points of the point pattern formed in the middle and the target area A measured on the left. 20L The dots forming the dot pattern are in the overlapping region A. 20R+20L They overlap each other.

[0040] In this way, overlapping region A 20L+20R The point density is set to high, making it easy to generate a distance image of vehicles ahead that are present in this lane. Furthermore, it is easy to measure the distance to vehicles ahead that are farther than the reference distance.

[0041] Figure 5 and Figure 6 This is an example of a reference distance.

[0042] like Figure 5 As illustrated in the example, the right measurement target area A 20R And left measurement target area A 20L Set at each of the first, second, and third reference distances. Figure 5 In the above, at a vehicle speed of 55 km / h, the first reference distance is 40 m corresponding to the distance between vehicles; at a vehicle speed of 85 km / h, the second reference distance is 80 m corresponding to the distance between vehicles; and at a vehicle speed of 110 km / h, the third reference distance is 120 m corresponding to the distance between vehicles.

[0043] 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 It can easily detect vehicles ahead of this vehicle (Va).

[0044] Next, a structural example of the optical detection device 20 will be described. In the following description, the configuration example of the right optical detection device 20R will be presented as representative.

[0045] Figure 7A This is a schematic configuration diagram of the right optical detection device 20R, and Figure 7B It is along Figure 7A The cross-sectional view taken from line VIIB-VIIB in the diagram.

[0046] like Figure 7A and Figure 7BAs shown, the right optical detection device 20R includes a light-emitting element 21, a correction lens 22, a mounting substrate 23 on which the light-emitting element 21 is mounted, and an oscillation circuit 24. These components are housed in a chassis 25, and a light-emitting window 26 is provided at a portion of the chassis 25, through which light emitted from the light-emitting element 21 and passing through the correction lens 22 passes. Furthermore, the right optical detection device 20R is connected to a control device 40 via a signal line 27.

[0047] The light-emitting element 21 includes a semiconductor laser that oscillates wavelengths (e.g., 905 nm, 940 nm, 1450 nm) in solar-dead regions, and a diffractive optical element (DOE) that converts the light emitted from the semiconductor laser into a point beam pattern. The semiconductor laser is, for example, a vertical cavity surface emitting laser (VCSEL), which includes an emitter that emits multiple laser beams (24 × 64). The diffractive optical element is, for example, a DOE composed of a multi-bend array, and splits the laser beam emitted from the VCSEL's emitter into multiple directions. Note that the semiconductor laser is not limited to a VCSEL and can also be a strip laser diode (LD) or a photonic crystal surface emitting laser (PCSEL). Furthermore, the point beam pattern can be formed using rotating mirrors (MEMS mirrors, galvanometer mirrors, polygonal mirrors) other than the diffractive optical element.

[0048] The correction lens 22 diffuses (concave lens) and focuses (convex lens) the dot beam pattern emitted from the light-emitting element 21 so as to have an illumination range shape set for each reference distance.

[0049] The oscillation circuit 24 responds to the control signal from the control device 40 to turn the light-emitting element 21 on or off in a predetermined pattern (pulse oscillation).

[0050] The light emission window 26 has a filtering function that allows light emitted from the light-emitting element 21 to pass through and prevents external light from entering.

[0051] The right optical detection device 20R includes multiple light-emitting elements 21 corresponding to multiple measurement distances (from a first reference distance to a third reference distance). Specifically, the right optical detection device 20R includes a right measurement target area A located at the first reference distance. 20R The combination of the light-emitting element 21 and the correction lens 22 forming a dot pattern laser beam is emitted into the right measurement target area A, which is set at the second reference distance. 20RThe combination of the light-emitting element 21 and the correction lens 22 that form a dot pattern laser beam, and the light emitted from the right measurement target area A set at the third reference distance. 20R The combination of a light-emitting element 21 and a correction lens 22 that form a dot pattern in a laser beam.

[0052] The right optical detection device 20R selects a light-emitting element 21 from among multiple light-emitting elements 21 according to the vehicle speed Va and emits a laser beam using the selected light-emitting element 21. This laser beam is emitted in the right measurement target area A. 20R A dot pattern is formed in the middle. Note that the vehicle speed Va can be provided, for example, from the driver assistance device 60, or can be obtained from a vehicle speed sensor (not shown) attached to the vehicle Va.

[0053] For example, when the vehicle speed Va is 55 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the first reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is positioned in the right measurement target area A at the first reference distance. 20R A dot pattern is formed in the middle. On the other hand, when the vehicle speed Va is 85 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the second reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is applied to the right measurement target area A set at the second reference distance. 20R A dot pattern is formed in the middle. Furthermore, when the vehicle speed Va is 110 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the third reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is positioned at the right measurement target area A at the third reference distance. 20R A dot pattern is formed in the middle.

[0054] Similarly, the left optical detection device 20L includes a plurality of light-emitting elements 21 corresponding to multiple measurement distances (from a first reference distance to a third reference distance). Specifically, the left optical detection device 20L includes light-emitting elements 21 that emit light onto a left measurement target area A positioned at the first reference distance. 20L The combination of the light-emitting element 21 and the correction lens 22 forming a dot pattern laser beam is emitted into the left measurement target area A, which is set at the second reference distance. 20L The combination of the light-emitting element 21 and the correction lens 22 forming a dot pattern laser beam, and the emission from the left measurement target area A set at the third reference distance. 20L The combination of a light-emitting element 21 and a correction lens 22 that form a dot pattern in a laser beam.

[0055] The left optical detection device 20L selects a light-emitting element 21 from among multiple light-emitting elements 21 according to the vehicle speed Va, and emits a laser beam using the selected light-emitting element 21. This laser beam is emitted in the left measurement target area A. 20L A dot pattern is formed in the middle.

[0056] For example, when the vehicle speed Va is 55 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the first reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is positioned in the left measurement target area A at the first reference distance. 20L A dot pattern is formed in the middle. On the other hand, when the vehicle speed Va is 85 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the second reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is applied to the left measurement target area A set at the second reference distance. 20L A dot pattern is formed in the middle. Furthermore, when the vehicle speed Va is 110 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the third reference distance, and emits a laser beam using the selected light-emitting element 21. This laser beam is positioned at the left measurement target area A at the third reference distance. 20L A dot pattern is formed in the middle.

[0057] The right optical detection device 20R with the above configuration is, for example, arranged in the lamp housing S1 of the vehicle lighting device 50R, and the lamp housing S1 is installed in the right side of the front part of the vehicle (the right side when facing forward of the vehicle). Similarly, the left optical detection device 20L with the above configuration is, for example, arranged in the lamp housing S1 of the vehicle lighting device 50L, and the lamp housing is installed in the left side of the front part of the vehicle (the left side when facing forward of the vehicle).

[0058] Figure 8 It is along Figure 2 The cross-sectional view taken from line VIII-VIII in the diagram.

[0059] like Figure 8 As shown, the vehicle lighting device 50R includes a bracket 52 and an optical axis adjustment mechanism 53 (e.g., an adjustment screw). A lighting unit 51 (semiconductor light-emitting element 51a, reflective surface 51b, projection lens 51c, movable light shield 51d) is attached to the bracket. The optical axis adjustment mechanism adjusts the optical axis of the lighting unit 51 by tilting the bracket 52. The lighting unit 51 and the optical axis adjustment mechanism 53 are arranged in a lamp housing S1 formed between an outer lens 54 and a housing 55 attached to the outer lens 54. Note that in Figure 8 In the figure, reference numeral 56 indicates an extension.

[0060] The right optical detection device 20R is arranged in the lamp housing S1 of the vehicle lighting device 50R in a state attached to the bracket 52, and the lighting equipment unit 51 is attached to the bracket (see...). Figure 8 Similarly, the left optical detection device 20L is arranged in the lamp housing S1 of the vehicle lighting device 50L, attached to the bracket 52, wherein the lighting unit 51 is attached to the bracket. Since the right optical detection device 20R (and the left optical detection device 20L) are attached to the bracket 52, which is tilted in this manner by the optical axis adjustment mechanism 53, the displacement of the laser beam emitted from the right optical detection device 20R (and the left optical detection device 20L) and the optical axis of the lighting unit 51 can be adjusted by the optical axis adjustment mechanism 53. Note that the right optical detection device 20R (and the left optical detection device 20L) does not necessarily have to be arranged in the lamp housing S1 of the vehicle lighting device 50, and can be arranged in appropriate locations such as the bumper, grille, side mirrors, and windshield of the vehicle Va. Note that in this case, by electrically connecting the right optical detection device 20R (and the left optical detection device 20L) to the optical adjustment mechanism 53 of the lighting equipment unit 51, the displacement of the laser beam can be adjusted in a manner similar to that in the case where the right optical detection device 20R (and the left optical detection device 20L) is attached to the bracket 52.

[0061] Next, the detection camera device 30 will be described.

[0062] The detection camera device 30 is configured to receive reflected light emitted from the optical detection device 20 and reflected by an object existing in the target area being measured, and to generate a master distance image in which the pixel values ​​are distance values. Figure 2 As shown, the detection camera device 30 is positioned at the center of the vehicle's interior (Va) in the vehicle's width direction. The detection camera device 30 captures an image of the portion in front of the vehicle (Va) through the windshield (wiper cleaning area). In this way, the overlapping area A in front of the vehicle's centerline... 20R+20L It can be positioned at the center of the field of view, thereby improving the accuracy of distance measurement for vehicles ahead.

[0063] Figure 9A This is a schematic configuration diagram of the detection camera device 30, and Figure 9B It is along Figure 9A The cross-sectional view taken from line IXB-IXB in the diagram.

[0064] like Figure 9A and Figure 9BAs shown, the detection camera device 30 includes an imaging element 31, a light-receiving lens 32, a mounting substrate 33 on which the imaging element 31 is mounted, and a receiving circuit 34. These components are housed in a housing 35, and a light-receiving window 36 is provided at a portion of the housing 35, through which light emitted from the optical detection device 20 and reflected by the object to be detected passes. Furthermore, the detection camera device 30 is connected to a control device 40 via a signal line 37.

[0065] Imaging element 31 is a single-photon avalanche diode (SPAD) capable of measuring the time of flight (direct ToF) of light emitted from optical detection device 20. Note that imaging element 31 has a resolution (0.1 megapixels (597 × 168 pixels) to 3 megapixels) capable of resolving distant objects to be detected. Note that a charge distribution type imaging element can be used to obtain the distance to the object to be detected by detecting the phase shift of optical detection device 20 (indirect ToF).

[0066] The light-receiving lens 32 is a lens for adjusting the viewing angle, so that the right measurement target area A is within the target area. 20R And left measurement target area A 20L The object to be detected becomes a size that can be resolved on the light-receiving surface of the imaging element 31. The viewing angle is typically set such that the target area A is measured on the right. 20R And left measurement target area A 20L The magnification on imaging element 31 is increased by 0.3 to 0.7 times.

[0067] The optical receiving circuit 34 performs imaging and outputs the captured image (distance image) in response to the control signal from the control device 40.

[0068] The light receiving window 36 has the function of selectively allowing only light emitted from the optical detection device 20 to pass through a bandpass filter.

[0069] The detection camera device 30 includes a plurality of imaging elements 31 corresponding to a plurality of measurement distances (from a first reference distance to a third reference distance). Specifically, the detection camera device 30 includes a combination of a light-receiving lens 32 and an imaging element 31 corresponding to a first reference distance, a combination of a light-receiving lens 32 and an imaging element 31 corresponding to a second reference distance, and a combination of a light-receiving lens 32 and an imaging element 31 corresponding to a third reference distance.

[0070] The detection camera device 30 selects an imaging element 31 from multiple imaging elements 31 based on the vehicle speed Va, and uses the selected imaging element 31 to capture the target area A located at a first reference distance. 20R Or measure the target area A on the left 20LThe image of the reflected light from the object is used to generate a right distance image or a left distance image, where the pixel values ​​are the distance values ​​of the main distance image.

[0071] For example, when the vehicle speed Va is 55 km / h, the detection camera device 30 selects the imaging element 31 corresponding to the first reference distance, and uses the selected imaging element 31 to capture the right measurement target area A set at the first reference distance. 20R Or measure the target area A on the left 20L The image of the reflected light from the object present in the image is used to generate a right distance image or a left distance image as the main distance image where the pixel value is the distance value. On the other hand, when the vehicle speed Va is 85 km / h, the detection camera device 30 selects the imaging element 31 corresponding to the second reference distance, and uses the selected imaging element 31 to capture the right measurement target area A set at the second reference distance. 20R Or measure the target area A on the left 20L The image of the reflected light from the object present in the image is used to generate a right distance image or a left distance image as the main distance image where the pixel value is the distance value. Furthermore, when the vehicle speed Va is 110 km / h, the detection camera device 30 selects an imaging element 31 corresponding to the third reference distance, and uses the selected imaging element 31 to capture the right measurement target area A set at the third reference distance. 20R Or measure the target area A on the left 20L The image of the reflected light from the object in the image is used to generate a right distance image or a left distance image as the main distance image where the pixel values ​​are the distance values.

[0072] As described above, by preparing an optical detection device 20 (imaging element 31) and a detection camera device 30 for each reference distance, it is possible to prevent the resolution at the far point from being reduced when the near point is set as a reference, and to prevent the field of view at the near point from narrowing when the far point is set as a reference, so that accurate road information can always be obtained.

[0073] Next, the control device 40 (control ECU) will be described.

[0074] The control device 40 (control ECU: electronic control unit) includes, for example, a processor (not shown), a storage unit 41, and a memory 42.

[0075] The processor is, for example, a central processing unit (CPU). One or more processors may exist. By executing a predetermined program (not shown) loaded from storage unit 41 (e.g., ROM) onto memory 42 (e.g., RAM), the processor functions as an imaging unit 43, an object distance calculation unit 44, a point density detection unit 45, an auxiliary distance image generation unit 46, and a communication unit 47. Some or all of these may be implemented in hardware.

[0076] Imaging unit 43 controls the right optical detection device 20R, the left optical detection device 20L, and the detection camera device 30 to capture right distance images and left distance images. For example, imaging unit 43 activates the right optical detection device 20R and the left optical detection device 20L at a predetermined illumination timing via a command from the driver assistance device 60, which is the main unit, and causes the detection camera device 30 to capture images at a predetermined timing.

[0077] Object distance calculation unit 44 calculates the distance to the right measurement target area A. 20R And left measurement target area A 20L Overlapping region A 20R+20L The distance between objects in the table.

[0078] Point density detection unit 45 detects the right measurement target area A 20R And left measurement target area A 20L Overlapping region A 20R+20L Point density in.

[0079] The auxiliary distance image generation unit 46 generates an auxiliary distance image to be sent to the driver assistance device 60, which is the main device, based on the right distance image and the left distance image, which are the main distance images sent from the detection camera device 30. The auxiliary distance image to be generated by the auxiliary distance image generation unit 46 is, for example, a composite distance image obtained by synthesizing the right distance image and the left distance image.

[0080] The communication unit 47 sends the auxiliary distance image generated by the auxiliary distance image generation unit 46 as a response to the command to the driver assistance device 60, which is the host device.

[0081] Next, an operational example of the vehicle forward-looking device 10 with the above configuration will be described.

[0082] Figure 10 This is a flowchart illustrating an operation example of the vehicle forward-looking device 10.

[0083] First, perform image processing (step S10).

[0084] Figure 11 This is a flowchart example of the imaging process. The following processes are mainly performed by the imaging unit 43.

[0085] First, the right optical detection device 20R selects a light-emitting element 21 from among multiple light-emitting elements 21 according to the vehicle speed Va (step S101), and uses the selected light-emitting element 21 to emit light onto the right measurement target area A. 20R A laser beam forming a dot pattern is generated (step S102). For example, when the vehicle speed Va is 55 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the first reference distance, and uses the selected light-emitting element 21 to emit light onto the right measurement target area A set at the first reference distance. 20R A laser beam forming a dot pattern. On the other hand, when the vehicle speed Va is 85 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the second reference distance, and uses the selected light-emitting element 21 to emit light onto the right measurement target area A set at the second reference distance. 20R A laser beam forming a dot pattern is generated. Furthermore, when the vehicle speed Va is 110 km / h, the right optical detection device 20R selects the light-emitting element 21 corresponding to the third reference distance, and uses the selected light-emitting element 21 to emit light onto the right measurement target area A set at the third reference distance. 20R A laser beam that forms a dot pattern.

[0086] Then, the detection camera device 30 selects an imaging element 31 from among multiple imaging elements 31 according to the vehicle speed Va (step S103), and uses the selected imaging element 31 to capture images of the target area A on the right. 20R The image of the reflected light from the object is obtained (step S104), and a right distance image is generated as the main distance image where the pixel values ​​are distance values ​​(step S105). The captured (generated) right distance image is sent to the control device 40.

[0087] Then, the left optical detection device 20L selects a light-emitting element 21 from among the multiple light-emitting elements 21 according to the vehicle speed Va (step S106), and uses the selected light-emitting element 21 to emit light onto the left measurement target area A. 20L A laser beam forming a dot pattern is generated (step S107). For example, when the vehicle speed Va is 55 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the first reference distance, and uses the selected light-emitting element 21 to emit light onto the left measurement target area A set at the first reference distance. 20LA laser beam forming a dot pattern. On the other hand, when the vehicle speed Va is 85 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the second reference distance, and uses the selected light-emitting element 21 to emit light onto the left measurement target area A set at the second reference distance. 20L A laser beam that forms a dot pattern. Furthermore, when the vehicle speed Va is 110 km / h, the left optical detection device 20L selects the light-emitting element 21 corresponding to the third reference distance, and uses the selected light-emitting element 21 to emit a laser beam that forms a dot pattern in the left measurement target area A20L set at the third reference distance.

[0088] Then, the detection camera device 30 selects an imaging element 31 from among multiple imaging elements 31 according to the vehicle speed Va (step S108), and uses the selected imaging element 31 to capture images of objects existing in the left measurement target area A. 20L The image of the reflected light from the object is captured (step S109), and a right distance image is generated as the main distance image where the pixel values ​​are the distance images (step S110). The captured (generated) right distance image is sent to the control device 40.

[0089] Here, in the overlapping region A 20L+20R When an object (e.g., a vehicle ahead) is present, two distances (i.e., the distance based on the right distance image and the distance based on the left distance image) can be obtained as the distance to the object. In other words, double quantization of distance information becomes possible.

[0090] Next, return to Figure 10 Then, perform auxiliary distance image generation processing (step S20).

[0091] Figure 12 This is a flowchart example of the auxiliary distance image generation process. The following processes are mainly performed by the auxiliary distance image generation unit 46.

[0092] First, the right distance image sent in step S105 and the left distance image sent in step S110 are acquired (step S201).

[0093] Then, a composite distance image (an example of an auxiliary distance image of this disclosure) is generated by synthesizing the right distance image and the left distance image obtained in step S201 (step S202).

[0094] Then, the synthetic distance image generated in step S202 is sent to the driver assistance device 60, which is the host device (step S203).

[0095] Then, return to Figure 10Perform object distance calculation processing (step S30).

[0096] Figure 13 This is a flowchart example of the object distance calculation process. The following processes are mainly performed by the object distance calculation unit 44.

[0097] First, detect the target area A on the right. 20R The inner vertical line L3R (see Figure 4 ) and the target area A on the left 20L The inner vertical line L3L (see Figure 4 Each of these steps (step S301). For example, the right measurement target region A can be detected based on the right distance image sent in step S105 (or the synthetic distance image generated in step S202). 20R The inner vertical line L3R. On the other hand, the left measurement target region A can be detected, for example, based on the left distance image sent in step S110 (or the synthetic distance image generated in step S202). 20L The inner vertical line L3L.

[0098] Then, the interval Wf between the inner vertical lines detected in step S301 (hereinafter also referred to as the inner boundary interval Wf) is calculated (step S302).

[0099] Then, using the interval Wf between the inner vertical lines calculated in step S302 and the known angle θi, the distance to the object Lc = (Wf / 2) / tan(θi) is calculated (step S22). Each element in this formula can be as follows: Figure 14 As shown. In other words, by obtaining the inner boundary interval Wf in this way, the third quantization of distance information becomes possible. Figure 14 It is a view that indicates the corresponding element in the formula used to obtain the distance Lc to the object.

[0100] Note that when the object (e.g., the vehicle in front) is farther than the reference distance, the inner boundary spacing Wf becomes greater than the optical axis AX. 20R and optical axis AX 20L The optical axis distance Wp is longer. On the other hand, when the object (e.g., a vehicle in front) is at the reference distance, the inner boundary spacing Wf becomes equal to the optical axis AX. 20R With optical axis AX 20L The optical axis distance Wp between them. Furthermore, when the object (e.g., a vehicle in front) is closer than the reference distance, the inner boundary spacing Wf becomes greater than the optical axis AX. 20R With optical axis AX 20L The optical axis distance Wp between them is short.

[0101] Next, return to Figure 10Perform point density detection processing (step S40).

[0102] Figure 15 This is an example of a flowchart for point density detection processing. Figure 16 (a) to Figure 16 (c) is a view showing the periodic change in point density. The following processing is mainly performed by the point density detection unit 45.

[0103] First, detect the overlapping region A. 20R+20L (See) Figure 4 The point density in the image (step S401). For example, overlapping regions A can be detected based on the synthetic distance image generated in step S202. 20R+20L Point density in.

[0104] If the object (e.g., a vehicle ahead) is present at the reference distance, the right measurement target area A is... 20R The point and the left measurement target area A 20L The points overlap, and therefore, the overlapping region A 20R+20L The point density in the middle decreases (see Figure 16 (a)).

[0105] On the other hand, if the object (e.g., a vehicle in front) moves closer than the reference distance, the point density instantaneously increases (see...). Figure 16 (b)), and if the object moves closer, the point density decreases (see (b)). Figure 16 (c)). The point density oscillates in this manner. This phenomenon also occurs similarly when an object (e.g., a vehicle in front) moves further than the reference distance.

[0106] Next, the period of change in the (detection) point density is calculated (step S402) to estimate the approach speed (or separation speed) of the object (step S403). This can be calculated, for example, based on the results of performing the processing in step S401 multiple times. The target area A is measured by right measurement when approaching the vehicle in front. 20R And left measurement target area A 20L Overlapping region A 20R+20L The point density oscillates periodically in this way, making four-quantization of distance information possible.

[0107] As described above, according to this embodiment, a large amount of distance information can be obtained, and the distance information can be provided to the host device (driver assistance device 60) with high certainty (accuracy). Note that, for the sake of simplicity, the above description has been based on a first reference distance to a third reference distance corresponding to the vehicle speed Va. If the vehicle speed Va is different from the above-described speed, a reference distance corresponding to an approximate vehicle speed can be selected for similar functions.

[0108] As described above, according to the first embodiment, a vehicle forward-looking device 10 can be provided that is capable of preventing false detection of objects such as nearby vehicles.

[0109] The reason is that the target area A is measured on the right. 20R And left measurement target area A 20L The objects are arranged symmetrically and at least partially overlap each other in the horizontal direction in front of the vehicle Va. Therefore, if an object (e.g., a vehicle in front) is present in the overlapping area, two distances (i.e., the distance based on the right distance image and the distance based on the left distance image) can be obtained as the distance to the object.

[0110] Next, the description will be modified.

[0111] Although an example has been described in the first embodiment above, a trapezoidal region whose width in the vertical direction becomes wider from the center side in the vehicle width direction toward the right in the vehicle width direction Va is used as the right measurement target region A. 20R Furthermore, the trapezoidal region that widens from the center side towards the left in the vertical direction of the vehicle's width Va is used as the left measurement target region A. 20L Right measurement target area A 20R And left measurement target area A 20L Not limited to this.

[0112] For example, such as Figure 17 As shown, a rectangular area extending from the center side of the vehicle's width (Va) towards the right side in the vehicle's width direction can be used as the right measurement target area A. 20R A rectangular area extending from the center side of the vehicle's width (Va) towards the left side in the vehicle's width direction can be used as the left measurement target area A. 20L . Figure 17 The target area A is measured on the right. 20R And left measurement target area A 20L The modified example.

[0113] In addition, such as Figure 18A As shown, the target area A is measured by dividing it into right regions. 20R (or left measurement target area A)20L The results obtained are for the corresponding regions 1A to 1E (see...) Figure 18B When the corresponding light-emitting units 1A to 1E are used as light-emitting elements 21 (VCSEL / LD) of the optical detection device 20, adjustments can be made to turn some of the light-emitting units 1A to 1E on and off and increase / decrease the output of the light-emitting units. Figure 18A This is a modified example of the light-emitting element 21 of the optical detection device 20. Figure 18B The target area A is measured on the right. 20R And left measurement target area A 20L The modified example.

[0114] For example, when it is desirable to obtain information about vehicles ahead in the current lane with high accuracy, the intensity of the reflected light from the detection light from the vehicle ahead can be increased by increasing the light output of the light-emitting unit 1A. Furthermore, when information about adjacent vehicles (adjacent lanes) is not needed, the light-emitting units (e.g., 1C to 1E) corresponding to the adjacent vehicles (adjacent lanes) can be turned off.

[0115] <Second Implementation Method>

[0116] Next, the second embodiment will be described.

[0117] Figure 19 This is a schematic configuration diagram of the vehicle forward-looking device 10A according to the second embodiment.

[0118] like Figure 19 As shown, the vehicle forward-looking device 10A differs from the vehicle forward-looking device 10 of the first embodiment in that it further includes an initial stage processing unit 48, a processing code generation unit 49, and a transmission data generation unit 49A. Other configurations are similar to those of the vehicle forward-looking device 10 of the first embodiment. Hereinafter, the differences from the vehicle forward-looking device 10 of the first embodiment will be primarily described, and configurations similar to those of the vehicle forward-looking device 10 of the first embodiment will be indicated by the same reference numerals, and descriptions suitable for such configurations will be omitted.

[0119] The initial stage processing unit 48, the processing code generation unit 49, and the data transmission generation unit 49A are implemented by a processor (not shown) that executes a predetermined program (not shown) loaded from the storage unit 41 (e.g., ROM) to the memory 42 (e.g., RAM).

[0120] The initial stage processing unit 48 performs initial stage processing on the distance image, including predetermined recognition processing. The distance image to be initially processed by the initial stage processing unit 48 is, for example, a right distance image and a left distance image (examples of the main distance images of this disclosure). The distance image is not limited to this, and the distance image to be initially processed by the initial stage processing unit 48 can be a synthetic distance image generated by the auxiliary distance image generation unit 46 (examples of the auxiliary distance images of this disclosure).

[0121] The initial stage processing to be performed by the initial stage processing unit 48 includes, for example, noise removal, pattern recognition, and processing code generation. The initial stage processing performed by the initial stage processing unit 48 may include detecting the right measurement target region A. 20R The inner vertical line L3R (see Figure 4 ) and left measurement target area A 20L The inner vertical line L3L (see Figure 4 The processing of each of them () Figure 13 Step S301) and point density detection processing ( Figure 15 Step S40 in the process.

[0122] Noise removal is the process of removing noisy light from the right and left distance images. Noisy light exists both during the day (when external light is strong) and at night (when there is incident light from flashes). Therefore, noise is removed from the measured distance image (primary distance image) generated at the detection camera device. For example, in Time-of-Flight (ToF) measurements, natural light noise is temporally random, while the reflected light from the object is temporally constant. Therefore, the target component can be amplified by smoothing the noise component (background) by superimposing the ranging data. In this way, the background and target components can be separated and extracted. This noise removal is achieved by performing a predetermined image processing (noise removal processing) on ​​the right and left distance images. The predetermined image processing (noise removal processing) can be a well-known noise removal process.

[0123] Pattern recognition is an example of the predetermined recognition process disclosed herein, and is a process for recognizing specific patterns (e.g., traffic lane lines, lane markings, vehicles ahead, inner vertical lines, dot density) in right-distance and left-distance images. The recognition of traffic lane lines, lane markings, and vehicles ahead can be achieved by performing predetermined image processing (image recognition processing) on ​​the right-distance and left-distance images. The predetermined image processing (image recognition processing) can be a known image recognition process. On the other hand, through... Figure 13 Steps S301 and S302 in the process realize the recognition of the inner vertical lines (detection of the interval Wf between the inner vertical lines).

[0124] Traffic lane lines extend forward from the left and right sides of this vehicle, parallel to the vehicle's direction of travel. Therefore, the identification of traffic lane lines is evaluated, while narrowing the scope to the area where the traffic lane lines should be located. Furthermore, the identification of vehicles ahead is evaluated, while narrowing the scope to the area in front of this lane. Additionally, if this vehicle (Va) changes lanes, the evaluation is performed while narrowing the scope to the area in front of the virtual lane lines sandwiched between virtual lane lines. Note that virtual lane lines are traffic lane lines that can be drawn to the left and right of this vehicle (Va).

[0125] The processing code generation is implemented, for example, by the processing code generation unit 49. The processing code generation unit 49 performs a processing code generation process to generate processing code representing the result of pattern recognition. Note that the processing code has a smaller data size than the synthetic distance image, which will be described later.

[0126] Figure 20 This is an example of handling code generation processes.

[0127] like Figure 20 As shown, the processing code generation unit 49 determines whether the predetermined conditions (out-of-range condition, conversion condition, valid condition) are met (steps S51, S52, S53), and if the conditions are met (step S51: yes, step S52: yes, step S53: yes), the processing code generation unit 49 generates processing code corresponding to the conditions (step S53).

[0128] First, the out-of-range condition will be described.

[0129] Figure 21 This is an example of an out-of-range condition and the processing code generated when the out-of-range condition is met. The correspondence between the out-of-range condition and the processing code is stored in storage unit 41. Figure 21 In the "(1) Traffic Lane Lines" field and the "(2) Ahead Vehicles" field, "Unapproved," "Line Shaded," and "Unevaluated" are described, and "ND" is described in the "(3) Boundary Spacing (Wf)" field, indicating out-of-range conditions. When out-of-range conditions are met, a processing code (e.g., "O1," "O2") is generated to indicate that traffic lane lines, etc., cannot be recognized. This processing code is a status code generated when the vehicle forward-looking device 10A cannot recognize traffic lane lines.

[0130] Here, the "Virtual Lane", "Within Reference Distance", and "Nearest Vehicle" fields in the "(2) Ahead Vehicle" field indicate the range for determining whether a vehicle ahead exists. Here, "Virtual Lane" refers to the virtual lane between the aforementioned virtual lane lines. "Within Reference Distance" refers to the "reference distance" of the optical detection device (light-emitting element 21) selected based on the vehicle's speed Va. "Nearest Vehicle" refers to the nearest vehicle within the virtual lane. In other words, if a vehicle ahead exists within the reference distance of the virtual lane, its existence is determined by setting the nearest vehicle as the target. Note that when traffic lane lines can be identified, traffic lane lines are used instead of virtual lane lines.

[0131] Note that the reason for setting "within the reference distance" to determine the presence of a vehicle ahead is as follows. Firstly, the reference distance of the detection device is set to the safe inter-vehicle distance corresponding to vehicle speed + α. In other words, a vehicle ahead within the safe inter-vehicle distance becomes a vehicle to be cautious of. Secondly, the measurement range of dToF is limited. For example, when the frequency of the detection light emitted from the detection device is 1MHz, the maximum measurement distance becomes 150m (round trip distance is 300m). Furthermore, when vehicles ahead are traveling in the same lane, and one vehicle is traveling on the left while another is traveling on the right, there are cases where different vehicles can be detected from the illumination range of the right detection device (e.g., a vehicle traveling further on the right) and the illumination range of the left detection device (e.g., a vehicle traveling near the left). In this case, the nearest vehicle becomes a vehicle to be cautious of.

[0132] The out-of-range conditions will be described in more detail below.

[0133] exist Figure 21 In the "(1) Traffic Lane Lines" field, "Unapproved" indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Unapproved," meaning that the traffic lane lines or lane drawings cannot be recognized as a result of the pattern recognition performed by the initial stage processing unit 48. On the other hand, "Line Shading" in the "(1) Traffic Lane Lines" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Line Shading," meaning that the line shading of the traffic lane lines or lane drawings exists as a result of the pattern recognition performed by the initial stage processing unit 48, and the (distance measurement) traffic lane lines or lane drawings can be recognized. Furthermore, in Figure 21 In the “(1) Traffic Lane Line” field, “Unevaluated” means that the pattern recognition result performed by the initial stage processing unit 48 is “Unevaluated”.

[0134] Note that in Figure 21In the "Traffic Lane Lines" field, the descriptions of "Right Lane Line;", "Lane Drawing:", and "Left Lane Line:" are followed by "Unapproved", "Line Shaded", and "Unevaluated" on the right side, each representing a state with a single column. In other words, the "Traffic Lane Lines" field indicates three states. For example, the first state is "Right Lane Line: Unapproved", "Lane Drawing: Unevaluated", and "Left Lane Line: Unapproved". Similarly, the second state is "Right Lane Line: Line Shaded", "Lane Drawing: Unevaluated", and "Left Lane Line: Unapproved", and the third state is "Right Lane Line: Unapproved", "Lane Drawing: Unevaluated", and "Left Lane Line: Line Shaded". In other words, if the pattern recognition result performed by the initial stage processing unit 48 corresponds to one of these three states, then the condition is met.

[0135] In addition, Figure 21 The "Unapproved" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "unapproved," meaning that the pattern recognition result performed by the initial stage processing unit 48 cannot identify the ahead vehicle. Specifically, this situation corresponds to the case where the ahead vehicle is traveling far beyond the measurement reference distance (far beyond the safe vehicle distance), or the case where the ahead vehicle is not present in this lane. On the other hand, the "Distance measurement using one (single quantization)" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "distance measurement using one," meaning that the ahead vehicle can be identified (distance measurement) using either the right distance image or the left distance image, and the ahead vehicle cannot be identified (distance measurement) using the other (single quantization).

[0136] also, Figure 21 The “ND” described in the “(3) Boundary Spacing (Wf)” field indicates that the boundary spacing (Wf) cannot be recognized (detected) as a result of pattern recognition performed by the initial stage processing unit 48.

[0137] Notice, Figures 21 to 23 The “traffic lane lines” are white lines that divide the lane on which vehicle Va is traveling (this lane). The “right lane line” is the traffic lane line to the right of vehicle Va. The “left lane line” is the traffic lane line to the left of vehicle Va. “Lane markings” are the road markings (e.g., road signs such as intersections and branches) between the right and left lane lines. “Vehicles ahead” are vehicles in front of vehicle Va that are in this lane and within a reference distance. “Boundary spacing (Wf)” is the spacing between inner vertical lines (see [reference]). Figure 4 ).

[0138] Figure 21The processing codes ("O1", "O2") described in the "Processing Code" field are examples of processing codes generated when the above out-of-range conditions are met. Figure 20 Step S51 in the code: Yes). The reason for the generation of these processing codes is as follows: Figure 21 The "Reason / Circumstances" field describes this. While the out-of-range conditions and the generated processing code when they are met have been described above, the out-of-range conditions and the generated processing code are not limited to... Figure 21 Those described in the text.

[0139] The conditions for the transformation will be described next.

[0140] Figure 22 This is an example of the transition conditions and the processing code generated when the transition conditions are met. The correspondence between the transition conditions and the processing code is stored in storage unit 41. Figure 22 In the text, “Unapproved,” “Line Shaded,” and “Unevaluated” described in the “(1) Traffic Lane Lines” field and “(2) Ahead Vehicles” field, and “ND” described in the “(3) Boundary Spacing (Wf)” field, represent transition conditions. When the transition conditions are met, a processing code (e.g., “T1,” “T2,” “T3,” “T4”) indicating that the vehicle Va is in a transition state is generated. This processing code is generated when (1) the vehicle forward-looking device 10A identifies road markings, etc., within the traffic lane lines, (2) when a vehicle in another lane merges into or changes lanes to enter the lane area, (3) when the vehicle Va crosses the traffic lane lines while changing lanes, and (4) when a vehicle appears in front of the vehicle Va within the virtual lane lines (virtual lane area) while the vehicle Va is changing lanes.

[0141] The conditions for the transition will be described in more detail below.

[0142] exist Figure 22 In the “(1) Traffic Lane Line” field, the “line shadow” refers to the recognition result of the pattern recognition performed by the initial stage processing unit 48, that is, as a result of the pattern recognition performed by the initial stage processing unit 48, there is a line shadow of the traffic lane line or a drawing in the lane, and the traffic lane line or the drawing in the lane can be recognized (distance measured). On the other hand, in Figure 21 The “evaluation failure” described in the “(1) traffic lane line” field indicates that the pattern recognition result performed by the initial stage processing unit 48 is “evaluation failure”.

[0143] In addition, Figure 22The "Not Approved" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result of the initial stage processing unit 48 is "Not Approved," meaning that the pattern recognition result of the initial stage processing unit 48 cannot identify the ahead vehicle. Specifically, this situation corresponds to the case where the ahead vehicle is traveling far beyond the measurement reference distance (far beyond the safe vehicle distance) or the case where the ahead vehicle is not present in this lane. On the other hand, the "Distance Measurement Using One (Single Quantization)" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Distance Measurement Using One," meaning that the ahead vehicle can be identified (distance measured) using either the right distance image or the left distance image, and the ahead vehicle cannot be identified (distance measured) using the other.

[0144] also, Figure 22 The “ND” described in the “(3) Boundary Spacing (Wf)” field indicates the result of pattern recognition performed by the initial stage processing unit 48, where the boundary spacing (Wf) cannot be recognized (detected).

[0145] Figure 22 The processing codes ("T1", "T2", "T3", "T4") described in the "Processing Code" field are those that meet the above conversion conditions. Figure 20 The example of processing code generated in step S52 (is) is as follows. The reason for generating this processing code is as follows: Figure 22 The "Reason / Circumstances" field describes this. While the transition conditions and the generated processing code when those conditions are met have been described above, the transition conditions and the processing code when they are met are not limited to... Figure 22 Those described in the text.

[0146] The valid conditions will be described next.

[0147] Figure 23 This is an example of a valid condition and the processing code generated when the valid condition is met. Here, valid means that the vehicle Va can recognize the actual traffic lane lines drawn on the road surface and is traveling in its lane. In other words, valid means that the vehicle Va can recognize whether there is a vehicle ahead traveling far in its lane. The correspondence between valid conditions and processing codes is stored in storage unit 41. Figure 23In the "(1) Traffic Lane Lines" field and the "(2) Ahead Vehicles" field, "Unapproved", "Line Shaded", and "Unevaluated" and "ND", "Inappropriate", and "Appropriate Value (Triple Quantization)" described in the "(3) Boundary Spacing (Wf)" field indicate states with relatively high reliability. If the validity conditions are met, a processing code (e.g., "V1", "V2", "V3", "V4") is generated to indicate that the measured distance value of the ahead vehicle is valid.

[0148] exist Figure 23 In this context, "zero quantization" refers to the situation where the vehicle ahead cannot be recognized by the vehicle forward-looking device 10A. "Single quantization" refers to the situation where the shadow of the vehicle ahead is recognized by the vehicle forward-looking device 10A and the distance can be measured using the probe light from one side; that is, the vehicle ahead can be identified (distance measurement) based on either the right or left distance image. "Second quantization" refers to the situation where the shadow of the vehicle ahead is recognized by the vehicle forward-looking device 10A and the distance can be measured using the probe light from both sides; that is, the vehicle ahead can be identified (distance measurement) based on both the right and left distance images. "Triple quantization" refers to the situation where the shadow of the vehicle ahead is recognized by the vehicle forward-looking device 10A, the distance can be measured using the probe light from both sides, and the boundary interval (Wf) is an appropriate approximation of the measured distance value (the measured distance value obtained through single or double quantization).

[0149] The valid conditions will be described in more detail below.

[0150] exist Figure 23 The “unapproved” description in the “(1) Traffic Lane Line” field indicates that the pattern recognition result performed by the initial stage processing unit 48 is “unapproved”, that is, as a result of the pattern recognition performed by the initial stage processing unit 48, the traffic lane line or the drawing in the lane cannot be recognized. On the other hand, the “line shadow” description in the “(1) Traffic Lane Line” field indicates that the pattern recognition result performed by the initial stage processing unit 48 is “line shadow”, that is, as a result of the pattern recognition performed by the initial stage processing unit 48, there is a line shadow of the traffic lane line or the drawing in the lane, and the traffic lane line or the drawing in the lane can be recognized (distance measurement).

[0151] In addition, Figure 23The "Not Approved" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Not Approved," meaning that the ahead vehicle cannot be identified as a result of the pattern recognition performed by the initial stage processing unit 48. On the other hand, the "Using One (Single Quantization) Distance Measurement" description in the "(2) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Using One Distance Measurement," meaning that the ahead vehicle can be identified (distance measurement) using either the right distance image or the left distance image, and the ahead vehicle cannot be identified (distance measurement) using the other (single quantization). Furthermore, the "Using Two (Double Quantization) Distance Measurement" description in the "(1) Ahead Vehicle" field indicates that the pattern recognition result performed by the initial stage processing unit 48 is "Using Two Distance Measurements," meaning that the distance value measured by the right distance image (the measured distance to the ahead vehicle) matches the distance value measured by the left distance image (double quantization) (the measured distance to the ahead vehicle).

[0152] also, Figure 23 The “ND” described in the “(3) Boundary Spacing (Wf)” field indicates that the boundary spacing (Wf) cannot be recognized (detected) as a result of pattern recognition performed by the initial stage processing unit 48. On the other hand, the “Inappropriate” described in the “(3) Boundary Spacing (Wf)” field indicates that the boundary spacing (Wf) is not an appropriate approximation of the measured distance value. Furthermore, the “Appropriate value” described in the “(3) Boundary Spacing (Wf)” field indicates that the boundary spacing (Wf) is an appropriate approximation of the measured distance value.

[0153] exist Figure 23 The processing codes ("V1", "V2", "V3", "V4") described in the "Processing Code" field are examples of processing codes generated under the condition that the above valid conditions are met. Figure 20 Step S53 in the code is: Yes). The reasons for generating these processing codes are as follows: Figure 23 The "Reason / Circumstances" field describes this. While the valid conditions and the generated processing code when those conditions are met have been described above, the valid conditions and the generated processing code are not limited to... Figure 23 Those described in the text.

[0154] As described above, the processing code generation unit 49 performs a processing code generation process to generate processing code representing the result of pattern recognition. Specifically, the processing code generation unit 49 determines whether an out-of-range condition, which is a predetermined condition, is met (see...). Figure 21 (See also) Figure 20In step S51), and if the condition is met (step S51: Yes), the processing code generation unit 49 generates processing code corresponding to the condition. Specifically, the processing code generation unit 49 reads the processing code corresponding to the condition from the storage unit 41.

[0155] In a similar manner, the code generation unit 49 determines whether the transformation conditions, which are predetermined conditions, are met (see [reference]). Figure 22 (See also) Figure 20 In step S52), and if the condition is met (step S52: yes), the processing code generation unit 49 generates processing code corresponding to the condition.

[0156] In a similar manner, the code generation unit 49 determines whether the valid conditions, which are predetermined conditions, are met (see [reference]). Figure 23 (See also) Figure 20 In step S53), and if the condition is met (step S53: yes), the processing code generation unit 49 generates processing code corresponding to the condition.

[0157] The transmission data generation unit 49A generates transmission data (e.g., packets) that includes processing codes generated by the processing code generation unit 49 and synthetic distance images generated by the auxiliary distance image generation unit 46. Figure 24 This is an example of transmitted data (packets) that includes processing code and synthesized distance images.

[0158] like Figure 24 As shown, the transmitted data includes header DT1, processing code DT2, basic information DT3, and composite distance image DT4.

[0159] The header DT1 includes the address of the driver assistance device 60 (the address of the vehicle network) as the transmission destination.

[0160] Processing code DT2 is a processing code generated by processing code generation unit 49. Driver assistance device 60 receives processing code DT2 before the main body of the response information (basic information DT3 and synthetic distance image DT4). This allows driver assistance device 60 to determine how to process the main body of the response information before receiving the main body of the response information. In other words, driver assistance device 60 can select the processing operation at an early stage. In other words, the data volume of the distance image "DT4" is large, thus the communication cycle becomes longer. However, when it is important to immediately determine the situation at the host device (driver assistance device 60), the host device (driver assistance device 60) can select the reception and next processing of "DT4" by referring to "DT2," which has a smaller data volume than "DT4."

[0161] Furthermore, the driver assistance device 60 can determine the usefulness of the synthetic distance image DT4 by referring to the processing code DT2 without performing any processing on the synthetic distance image DT4. In other words, the driver assistance device 60 can determine the usefulness of the synthetic distance image DT4 as a sensing result of an early stage. Therefore, the driver assistance device 60 can quickly perform various subsequent processing.

[0162] Basic information DT3 is fundamental information data used to process the processed distance image (synthetic distance image). Basic information DT3 includes, for example, measurement time (e.g., the time when the optical detection devices 20R and 20L emit detection light (laser beams), received vehicle speed (the speed of the vehicle Va transmitted from the driver assistance device 60 to the vehicle forward-looking device 10A), and reference distance (a reference distance set by the vehicle forward-looking device 10A). Note that basic information DT3 may include other information. For example, when narrowing the reading angle of the imaging element 31, basic information DT3 may include horizontal and vertical viewing angle information, starting pixel address, etc.

[0163] The synthetic distance image DT4 is data of a synthetic distance image (auxiliary distance image) generated by the auxiliary distance image generation unit 46.

[0164] The communication unit 47 sends the transmission data generated by the transmission data generation unit 49A to the driver assistance device 60, which is the host device (an example of different devices in this disclosure). For example, the communication unit 47 sends the transmission data as a response to a command to the driver assistance device 60, which is the host device. Note that the processing code generated by the processing code generation unit 49 and the composite distance image generated by the auxiliary distance image generation unit 46 are not limited to a grouped form and can be sent to the driver assistance device 60, which is the host device, in a state where they are associated with each other.

[0165] Next, an operational example of the vehicle forward-looking device 10A with the above configuration will be described.

[0166] Figure 25 This is a flowchart illustrating an operation example of the vehicle forward-looking device 10A.

[0167] First, image processing is performed (step S10). Imaging processing has already been described (see...). Figure 11 Therefore, the description will be omitted.

[0168] Next, initial stage processing is performed (step S60). This initial stage processing is implemented by the initial stage processing unit 48. The initial stage processing unit 48 performs initial stage processing (noise removal, pattern recognition, and processing code generation) on the right and left distance images captured in step S10, including predetermined recognition processing. Furthermore, the initial stage processing unit 48 performs detection of the right measurement target region A. 20R The inner vertical line L3R (see Figure 4 ) and left measurement target area A 20L The inner vertical line L3L (see Figure 4 The processing of each of them () Figure 13 (Step S301 in the above). In this case, the processing code generation in step S60 is implemented by the processing code generation unit 49.

[0169] like Figure 20 As shown, the processing code generation unit 49 determines whether the predetermined conditions (out-of-range condition, conversion condition, valid condition) are met (steps S51, S52, S53), and if the conditions are met (step S51: yes, step S52: yes, step S53: yes), the processing code generation unit 49 generates processing code corresponding to the conditions (e.g., Figure 21 (Processing code "O1" in step S53).

[0170] Then, a synthesized distance image (an example of an auxiliary distance image of this disclosure) is generated by synthesizing the right distance image and the left distance image that have undergone the initial stage processing in step S60 (step S61). This is implemented by the auxiliary distance image generation unit 46.

[0171] Then, transmission data is created (step S62). This is implemented by the transmission data generation unit 49A. The transmission data generation unit 49A generates groups including the processing code generated in step S60 and the synthetic distance image generated in step S62 (see...). Figure 24 () as transmitted data.

[0172] Then, the transmission data generated in step S62 is sent to the driver assistance device 60, which is the host device (step S20A5). This is achieved by the communication unit 47.

[0173] As described above, according to the second embodiment, a vehicle forward-looking device 10A can be provided, which enables different devices (e.g., driver assistance device 60) to determine the usefulness of the synthetic distance image as a result of early-stage sensing.

[0174] In addition to the synthetic distance image as a result of sensing, this is also achieved by sending processing codes representing the usefulness of the sensing results to different devices (e.g., driver assistance device 60).

[0175] The corresponding values ​​indicated in the above embodiments are examples, and of course, different values ​​may be used appropriately.

[0176] The above embodiments are merely examples in each aspect. The invention should not be interpreted in a limited way based on the description of the above embodiments. For example, by combining... Figure 18A The light-emitting element 21 of the optical detection device 20 and the high-resolution imaging element 31 of the detection camera device 30 shown can be combined into a group, with the light-emitting element 21 and imaging element 31 provided for each of the first to third reference distances. Furthermore, the detection camera device 30 can be positioned at the end of the front window (the area swept by the wiper). Note that in this case, a function similar to the above-described function can be obtained by applying tilt viewing correction to the captured image. In this way, the invention can be implemented in various forms without departing from the spirit and main features of the invention.

[0177] This application claims the benefit of Japanese Patent Application No. 2023-158224, filed on September 22, 2023, the entire contents of which are incorporated herein by reference.

[0178] List of reference numerals

[0179] 10, 10A Vehicle Forward-Looking Device

[0180] 20 Optical detection devices

[0181] 20L Left Optical Detection Device

[0182] 20R Right Optical Detection Device

[0183] 21 Light-emitting elements

[0184] 22 Correction Lens

[0185] 23 Mounting substrate

[0186] 24 Oscillating Circuit

[0187] 25. Outer shell

[0188] 26 Light emission windows

[0189] 30. Detection camera device

[0190] 31 Imaging elements

[0191] 32. Light receiving lens

[0192] 33 Mounting substrate

[0193] 34 Receiving Circuit

[0194] 35. Outer shell

[0195] 36 Optical receiving window

[0196] 40 Control device

[0197] 41 storage units

[0198] 42 Memory

[0199] 43 imaging units

[0200] 44 Object Distance Calculation Unit

[0201] 45-point density detection unit

[0202] 46 Auxiliary distance image generation units

[0203] 47 Communication Unit

[0204] 48 Initial Stage Processing Unit

[0205] 49. Processing code generation unit

[0206] 49A Transmission Data Generation Unit

[0207] 50, 50R vehicle lighting

[0208] 51 Lighting Equipment Unit

[0209] 51av semiconductor light-emitting element

[0210] 51b reflective surface

[0211] 51c projection lens

[0212] 51d movable shadow

[0213] 52 brackets

[0214] 53 Optical Axis Adjustment Mechanism

[0215] 54 External Lens

[0216] 55 Housing

[0217] 60 Driver assistance devices

[0218] A 20L Left measurement target area

[0219] A 20R Right measurement target area

[0220] AX 20L AX 20R Optical axis

[0221] Cp1, Cp2 center points

[0222] H1-H1 horizontal line

[0223] Hp optical detection device

[0224] L1L, L1R upper side

[0225] L2L, L2R lower side

[0226] Inner vertical lines of L3L and L3R

[0227] L4L, L4R Outer Vertical Lines

[0228] Lc distance

[0229] Lower endpoints of P1b and P2b

[0230] Upper endpoints of P1t and P2t

[0231] S1 lamp housing

[0232] V1-V1 vertical line

[0233] V2-V2 vertical line

[0234] Va This vehicle

[0235] Wf boundary spacing

[0236] Wp optical axis distance

[0237] θi angle

Claims

1. A vehicle forward-looking device, the vehicle forward-looking device being mounted on a vehicle, the vehicle forward-looking device comprising: A right optical detection device is disposed in the right side of the front end of the vehicle and is configured to emit a laser beam that forms a dot pattern in a right measurement target area located at a predetermined reference distance in front of the vehicle. A left optical detection device is disposed in the left side of the front end portion of the vehicle and is configured to emit a laser beam that forms a dot pattern in a left measurement target area located at the predetermined reference distance in front of the vehicle. as well as A detection camera device is configured to capture images of reflected light emitted from the right optical detection device and reflected by an object present in the right measurement target area, and generate a right distance image as a primary distance image where pixel values ​​are distance values; and to capture images of reflected light emitted from the left optical detection device and reflected by an object present in the left measurement target area, and generate a left distance image as a primary distance image where pixel values ​​are distance values. The right measurement target area and the left measurement target area are arranged symmetrically and at least partially overlap each other in the horizontal direction about the front of the vehicle.

2. The vehicle forward-looking device according to claim 1, wherein, The outline of the right-side measurement target area has a trapezoidal shape, the trapezoidal shape having a width that widens vertically from the center side in the vehicle width direction toward the right side in the vehicle width direction, and The outline of the left measurement target area has a trapezoidal shape, which has a width that becomes wider in the vertical direction from the center side in the vehicle width direction toward the left side in the vehicle width direction.

3. The vehicle forward-looking device according to claim 2, wherein, The dot density of the dot pattern formed in the right measurement target area is set high on the center side in the vehicle width direction and becomes lower towards the right side in the vehicle width direction. The dot density of the dot pattern formed in the left measurement target area is set high on the center side in the vehicle width direction and becomes lower towards the left side in the vehicle width direction.

4. The vehicle forward-looking device according to claim 2, further comprising an object distance calculation unit, the object distance calculation unit being configured to calculate the distance to an object existing in the overlapping area of ​​the right measurement target area and the left measurement target area based on the distance between the inner vertical line of the right measurement target area and the inner vertical line of the left measurement target area.

5. The vehicle forward-looking device according to claim 4, further comprising a dot density detection unit configured to detect the periodicity of dot density change in the overlapping area of ​​the right measurement target area and the left measurement target area.

6. The vehicle forward-looking device according to claim 1, further comprising: The lighting equipment unit is attached to the bracket; as well as An optical axis adjustment mechanism is configured to adjust the optical axis of the lighting device unit by tilting the bracket. The optical detection device is attached to the bracket.

7. The vehicle forward-looking device according to claim 1, further comprising an auxiliary distance image generation unit configured to generate an auxiliary distance image to be sent to different devices based on the right distance image and the left distance image.

8. The vehicle forward-looking device according to claim 1, wherein, Each of the right optical detection device and the left optical detection device includes multiple light-emitting elements corresponding to multiple measurement distances. The light-emitting element is selected from the plurality of light-emitting elements according to the vehicle speed. The detection camera device includes multiple imaging elements corresponding to the multiple measurement distances, and The imaging element is selected from the plurality of imaging elements according to the vehicle speed.

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