External environment recognition device

Abstract

The present invention provides an external vehicle environment recognition device for realizing appropriate following control. The external vehicle environment recognition device comprises: a path derivation unit for estimating a vehicle path (210) as a path of a vehicle (1), and deriving a target path (220) that passes through a target vehicle (3) as a target of following control and forms a parallel curve with the vehicle path; a speed derivation unit for deriving a target speed vector Vs as a speed vector of the target vehicle; and a following control unit for performing following control based on the target speed vector itself if an angle θ formed between the target speed vector and a tangent line (222) of the target path at the position of the target vehicle is within a predetermined angle range, and performing following control based on a speed component (target tangent speed component Vt) of the target speed vector at the target tangent line if the angle θ is outside the predetermined angle range.

Description

Technical Field

[0001] The present invention relates to a vehicle exterior environment recognition device that follows a target vehicle located in the traveling direction of a host vehicle. Background Art

[0002] Conventionally, there is known ACC (Adaptive Cruise Control) technology as disclosed in Patent Document 1. This ACC technology detects three-dimensional objects such as vehicles ahead of the vehicle and performs control to avoid collision with the preceding vehicle or to maintain a safe distance between the vehicle and the preceding vehicle.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 3349060 Summary of the Invention

[0006] Technical issues

[0007] In some vehicles, following control is performed as a function of the aforementioned ACC. Following control is control to make the host vehicle follow the preceding vehicle while maintaining a constant distance between the preceding vehicle and the host vehicle when there is a preceding vehicle in the host vehicle's path.

[0008] To achieve this following control, the vehicle derives the velocity component Vz of the preceding vehicle (hereinafter referred to as the target vehicle) in its direction of travel and, based on this velocity component, maintains a constant inter-vehicle distance. Even if a vehicle cuts in front of the vehicle, the vehicle's velocity component in its direction of travel is sufficiently low depending on the angle of the cut-in, allowing for appropriate response, such as by reducing the vehicle's speed.

[0009] However, if such control is always performed, the speed component will unnecessarily decrease when the preceding vehicle turns at a distance, and the speed of the host vehicle will also decrease rapidly. As a result, the driver may feel uncomfortable with the change in the speed of the host vehicle.

[0010] Furthermore, if the field of view of cameras used for follow-up control is increased and the resolution is improved in the future, it will be possible to accurately deduce the turning of the preceding vehicle, and changes in the speed of the host vehicle may become significant.

[0011] In view of the above problems, an object of the present invention is to provide a vehicle exterior environment recognition device capable of realizing appropriate following control.

[0012] Technical Solution

[0013] In order to solve the above-mentioned problems, the vehicle exterior environment recognition device of the present invention includes: a travel path derivation unit, which estimates the travel path of the own vehicle and derives the target travel path, wherein the own vehicle travel path is the travel path of the own vehicle, and the target travel path passes through the target vehicle as the object of following control and forms a parallel curve with the travel path of the own vehicle; a speed derivation unit, which derives the target speed vector, which is the speed vector of the target vehicle; and a following control unit, which performs following control based on the object speed vector itself if the angle formed by the object speed vector and the object tangent is within a predetermined angle range, and performs following control based on the speed component of the object speed vector at the object tangent if the angle is outside the predetermined angle range, wherein the object tangent is the tangent of the object travel path at the position of the target vehicle.

[0014] The host vehicle's travel path and the object's travel path may be represented as portions of concentric circles.

[0015] If the radius of the vehicle's travel path when expressed as a circle is equal to or larger than a predetermined length, the vehicle's travel path can be made a straight line.

[0016] Technical Effects

[0017] According to the present invention, appropriate following control can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a block diagram showing the connection relationship of the vehicle exterior environment recognition system.

[0019] Figure 2 This is an explanatory diagram for explaining a luminance image.

[0020] Figure 3 This is an explanatory diagram for explaining a distance image.

[0021] Figure 4 This is a functional block diagram showing the general functions of the vehicle exterior environment recognition device.

[0022] Figure 5 This is a flowchart showing the flow of the vehicle exterior environment recognition process.

[0023] Figure 6 This is an explanatory diagram for explaining the travel path of the vehicle.

[0024] Figure 7 This is an illustration for explaining the path of an object.

[0025] Figure 8 This is an explanatory diagram for explaining the velocity vector of the target vehicle.

[0026] Figure 9This is an explanatory diagram for explaining follow-up control.

[0027] Figure 10 This is an explanatory diagram for explaining follow-up control.

[0028] Explanation of symbols

[0029] 1 vehicle

[0030] 2 Candidate Vehicles

[0031] 3 Target vehicles

[0032] 160 Road Surface Determination Department

[0033] 162 Three-dimensional Object Determination Department

[0034] 164 Travel path derivation unit

[0035] 166 Speed Derivation Unit

[0036] 168 Follow-up Control Department

[0037] 210 Vehicle's travel path

[0038] 220 Object Travel Path

[0039] 222 Object Tangent DETAILED DESCRIPTION

[0040] Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention and, unless otherwise specified, do not limit the invention. It should be noted that in this specification and the accompanying drawings, elements having substantially the same functions and structures are denoted by the same reference numerals to avoid repeated description. Furthermore, elements not directly related to the present invention are omitted from illustration.

[0041] (External vehicle environment recognition system 100)

[0042] Figure 1 1 is a block diagram showing the connection relationship of the vehicle exterior environment recognition system 100. The vehicle exterior environment recognition system 100 includes an imaging device 110, a vehicle exterior environment recognition device 120, and a vehicle control device 130.

[0043] The camera device 110 is configured to include camera elements such as a CCD (Charge-Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor), and is capable of capturing the exterior environment in front of the vehicle 1 and generating a luminance image (a color image or a monochrome image) containing at least luminance information. Furthermore, the camera devices 110 are disposed approximately horizontally and separately on the side of the vehicle 1 in the direction of travel, with the optical axes of the two camera devices 110 being approximately parallel. The camera device 110 continuously generates luminance images of three-dimensional objects present in the detection area in front of the vehicle 1 at, for example, 1 / 60 second per frame (60 fps). Three-dimensional objects include not only independently existing objects such as vehicles, bicycles, pedestrians, traffic lights, road signs, guardrails, and buildings, but also objects that can be identified as a part of a vehicle, such as vehicle lights and bicycle wheels.

[0044] Furthermore, the vehicle exterior environment recognition device 120 obtains luminance images from each of the two cameras 110 and, using so-called pattern matching, derives disparity information. This disparity information includes disparity and the image position indicating the position of an arbitrary block within the image. Here, a block is represented, for example, by an array of 4 pixels horizontally by 4 pixels vertically. Horizontal refers to the horizontal orientation of the captured image, while vertical refers to the vertical orientation of the captured image. Pattern matching is a method for retrieving a block from one luminance image that corresponds to a block arbitrarily extracted from another luminance image.

[0045] For example, functions used to evaluate the degree of consistency between blocks in pattern matching include SAD (Sum of Absolute Difference), which measures the difference in brightness; SSD (Sum of Squared Difference), which measures the squared difference; and NCC (Normalized Cross Correlation), which measures the similarity of the variances obtained by subtracting the average from the brightness of each pixel. The vehicle exterior environment recognition device 120 performs this block-by-block disparity derivation process on all blocks reflected in a 600-pixel x 200-pixel detection area. Here, the blocks are 4 pixels x 4 pixels, but the number of pixels within a block can be set arbitrarily.

[0046] However, while the vehicle exterior environment recognition device 120 can derive disparity for each block, which serves as a unit of detection resolution, it cannot identify which 3D object that block is part of. Therefore, disparity information is not derived per 3D object, but rather independently for each unit of detection resolution within the detection area, such as a block. The image corresponding to this derived disparity information is referred to as a range image, distinct from the aforementioned luminance image.

[0047] Figure 2 is an explanatory diagram for explaining the luminance image 126. Figure 3 is an explanatory diagram for explaining the distance image 128. For example, it is assumed that two imaging devices 110 generate a distance image 128 for the detection area 124. Figure 2 However, for ease of understanding, only one of the two brightness images 126 is schematically shown here. The vehicle exterior environment recognition device 120 calculates the parallax of each block based on the brightness image 126 to form Figure 3 Such a distance image 128. Each block in the distance image 128 is associated with the parallax of the block. Here, for convenience of explanation, the blocks from which the parallax is derived are indicated by black dots.

[0048] Furthermore, the vehicle exterior environment recognition device 120 first identifies the road surface using the luminance values (or color values) of the luminance image 126 and the three-dimensional positional information in real space, including the relative distance to the host vehicle 1, calculated based on the distance image 128. The vehicle exterior environment recognition device 120 then groups blocks on the identified road surface that have equal color values and similar three-dimensional positional information as three-dimensional objects, and determines which object, for example, a preceding vehicle or a bicycle, the three-dimensional object in the detection area ahead of the host vehicle 1 corresponds to.

[0049] If the vehicle exterior environment recognition device 120 identifies a solid object, the host vehicle 1 is controlled to avoid a collision with the object or to maintain a safe distance from the preceding vehicle. Following control, when a preceding vehicle is in the host vehicle's path, assists the driver's acceleration and braking operations to cause the host vehicle 1 to follow the preceding vehicle, maintaining a constant distance between them.

[0050] It should be noted that the relative distance is calculated by converting the parallax information of each block in the distance image 128 into three-dimensional position information using a so-called stereo method. Here, the stereo method is a method that uses triangulation to derive the relative distance of a 3D object from the camera 110 based on the parallax of the 3D object.

[0051] The vehicle control device 130 is comprised of an ECU (Electronic Control Unit). It receives driver input via a steering wheel 132, an accelerator pedal 134, and a brake pedal 136, and transmits this input to a steering mechanism 142, a drive mechanism 144, and a brake mechanism 146, thereby controlling the vehicle 1. Furthermore, the vehicle control device 130 controls the steering mechanism 142, the drive mechanism 144, and the brake mechanism 146 based on instructions from the vehicle exterior environment recognition device 120.

[0052] As described above, in the vehicle exterior environment recognition system 100, blocks with equal color values and close three-dimensional position information are grouped together to form three-dimensional objects. For example, if there is a preceding vehicle in front of the host vehicle 1, the blocks corresponding to the back of the preceding vehicle are grouped together as a three-dimensional object because their relative distances are equal. Based on the characteristics of the three-dimensional object obtained from this grouping, it can be determined that it is the preceding vehicle.

[0053] Furthermore, the vehicle exterior environment recognition device 120 identifies all preceding vehicles in front of the host vehicle 1 as candidate vehicles. If any candidate vehicles exist on the host vehicle's path, the candidate vehicle with the shortest relative distance is designated as the target vehicle. Furthermore, the vehicle exterior environment recognition device 120 performs following control based on the relative distance and relative speed to the candidate vehicle with the shortest relative distance. Here, the host vehicle's path represents a path wider than the host vehicle 1, such as the lane in which the host vehicle 1 is predicted to travel from the current moment onward. For example, the vehicle exterior environment recognition device 120 can derive the target vehicle's velocity component Vz in the host vehicle's directional direction and control the vehicle's distance from the host vehicle to maintain a constant distance based on this velocity component Vz. Even if a candidate vehicle cuts in front of the host vehicle 1, the velocity component Vz in the host vehicle's directional direction is sufficiently low depending on the angle of the cut-in, allowing the host vehicle 1 to respond appropriately, such as by reducing its speed.

[0054] However, if this control is uniformly applied to both a candidate vehicle cutting in and the target vehicle continuing ahead, even if the target vehicle turns at a distance, it will be identified as a candidate vehicle cutting in. This will cause the velocity component Vz to decrease unnecessarily, and the speed of the host vehicle will also decrease rapidly. This can cause the driver to feel uncomfortable with the changes in the speed of the host vehicle. Therefore, in this embodiment, the goal is to achieve appropriate following control by accurately determining the speed of the target vehicle.

[0055] The following describes in detail the configuration of the vehicle exterior environment recognition device 120 for achieving such a purpose. Here, a detailed description will be given of what speed should be used as the speed selection for the target vehicle, which is characteristic of this embodiment.

[0056] (External environment recognition device 120)

[0057] Figure 4 1 is a functional block diagram showing the general functions of the vehicle exterior environment recognition device 120. Figure 4 As shown, the vehicle exterior environment recognition device 120 includes an I / F unit 150 , a data holding unit 152 , and a central control unit 154 .

[0058] The I / F unit 150 is an interface for bidirectionally exchanging information with the imaging device 110 and the vehicle control device 130. The data storage unit 152 is composed of a RAM, a flash memory, an HDD, etc., and stores various information required for processing by each functional unit described below.

[0059] The central control unit 154 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing programs, and RAM serving as a work area. It controls the I / F unit 150, the data storage unit 152, and other components via a system bus 156. Furthermore, in this embodiment, the central control unit 154 also functions as a road surface identification unit 160, a three-dimensional object identification unit 162, a travel path derivation unit 164, a speed derivation unit 166, and a following control unit 168. The following description of the vehicle exterior environment recognition process will be further detailed based on the operations of each functional unit of the central control unit 154.

[0060] (External environment recognition and processing)

[0061] Figure 5 It is a flowchart showing the process of the vehicle exterior environment recognition processing. In the vehicle exterior environment recognition processing, the road surface determination unit 160 determines the road surface in front of the vehicle 1 (S200). Then, the three-dimensional object determination unit 162 determines the candidate vehicle (S202). Then, the path derivation unit 164 derives the vehicle's path and the object path that passes through the object vehicle and forms a parallel curve with the vehicle's path (S204). Then, the speed derivation unit 166 derives the speed vector of the object vehicle, i.e., the object speed vector (S206). Then, the following control unit 168 performs following control based on the angle formed by the object speed vector and the tangent of the object path at the position of the object vehicle, i.e., the object tangent (S208).

[0062] (Road surface determination process S200)

[0063] The road surface identification unit 160 identifies the road surface in front of the host vehicle 1 based on the brightness image 126 and the distance image 128. Furthermore, the road surface identification unit 160 identifies the road surface in front of the host vehicle 1 based on lane boundaries, such as white lines on the left and right sides of the lane in which the host vehicle 1 is traveling. It should be noted that the road surface identification unit 160 is not limited to identifying the road surface in front of the host vehicle 1 based on the left and right lane boundaries. The road surface identification unit 160 can also identify the road surface in front of the host vehicle 1 based on three-dimensional objects, such as road markings, walls, steps on the roadside, poles, and fences.

[0064] (3D Object Determination Process S202)

[0065] The three-dimensional object identification unit 162 identifies three-dimensional objects that are vertically above the road surface identified by the road surface identification unit 160. Specifically, the three-dimensional object identification unit 162 determines that blocks whose height from the road surface is within a range of ± a predetermined distance (e.g., 0.3 m) are not three-dimensional objects. On the other hand, the three-dimensional object identification unit 162 identifies blocks whose height from the road surface is greater than the predetermined distance as candidates for three-dimensional objects that protrude in the height direction from the road surface.

[0066] Furthermore, the three-dimensional object identification unit 162 groups the blocks at equal relative distances from the vehicle 1 from among the multiple blocks designated as candidates for three-dimensional objects vertically above the road surface, and identifies them as three-dimensional objects. Next, the three-dimensional object identification unit 162 determines whether the three-dimensional object is a candidate vehicle (the preceding vehicle) based on the three-dimensional object similarity (shape, size, etc.) of the point cluster constituting the three-dimensional object. It should be noted that the determination of whether a three-dimensional object is a vehicle can be made using various existing technologies, so a detailed description thereof is omitted here.

[0067] (Travel Route Derivation Process S204)

[0068] Figure 6 This is an explanatory diagram for explaining the vehicle's path. Vehicle 1 moves along various paths depending on the road and destination. First, the path derivation unit 164 estimates the vehicle's path, i.e., the vehicle's path 210, based on the vehicle's speed and angular velocity about the vertical axis, acquired by an inertial measurement unit (IMU) mounted on the vehicle, the lane boundaries on both sides of the lane, and map information (or road information) acquired by a GPS navigation device.

[0069] For example, in the vehicle 1 Figure 6 When the track shown by the arrow in FIG. 1 is moving, the estimated track under the condition of maintaining the track becomes the vehicle travel path 210 shown by the solid line. Here, based on the situation that the vehicle 1 is turning, as shown in FIG. Figure 6As shown, it is estimated that the host vehicle 1 moves along a circle represented by a radius R on the road surface on which the host vehicle 1 is traveling. Therefore, the host vehicle travel path 210 describes an arc.

[0070] Furthermore, there are various candidate vehicles 2 ahead of the host vehicle 1. These candidate vehicles 2 include, in addition to vehicles traveling in the same direction as the host vehicle 1, vehicles that cut in on the path of the host vehicle 1, vehicles traveling in the opposite lane, and vehicles traveling on a road orthogonal to the path of the host vehicle 1.

[0071] If the candidate vehicle 2 is present in the host vehicle path 210 , for example, in the lane in which the host vehicle 1 is traveling, the path derivation unit 164 sets the candidate vehicle 2 as the target vehicle 3 to be controlled by the following control unit 168 described later.

[0072] Figure 7 : is an explanatory diagram for explaining the target travel path. The travel path derivation unit 164 derives the target travel path 220, which passes through the horizontal center of the back of the target vehicle 3 and forms a parallel curve with the vehicle travel path 210 (relative to the curve, the curve is located at a certain distance from each point on the curve in the normal direction). Specifically, as Figure 7 As shown by the middle dashed line, the path derivation unit 164 sets a circle that passes through the horizontal center of the back of the target vehicle 3 and is concentric with the vehicle path 210 (circle with the same center) as the target path 220. Figure 7 As shown, the radius R of the host vehicle's path 210 and the target path 220 do not necessarily coincide. It should be noted that the point through which the parallel curve passes is not limited to the horizontal center of the back of the target vehicle 3, but can be any position on the target vehicle 3. For example, it can also be the horizontal center of the target vehicle 3.

[0073] If the vehicle path 210 is a straight line or a curve that is close to a straight line, the size of the circle (radius) becomes very large. Therefore, since the vehicle path 210 is approximated by a circle, the processing load increases, which may affect the calculation time.

[0074] Therefore, if the radius R of the host vehicle's path 210, when represented as a circle, is greater than or equal to a predetermined length, the path derivation unit 164 processes the host vehicle's path 210 as a straight line. In this case, the path derivation unit 164 sets a straight line that passes through the target vehicle 3 and is parallel to the straight line representing the host vehicle's path 210 as the target path 220. This prevents an increase in the processing load.

[0075] (Speed Derivation Process S206)

[0076] Figure 8 3 is an explanatory diagram for explaining the velocity vector of the target vehicle 3. Figure 8 and later shown Figure 9 、 Figure 10 The vector in is represented by a two-dimensional vector parallel to the road surface. The speed derivation unit 166 adds the relative speed vector of the target vehicle 3 with respect to the host vehicle 1, which is derived based on the inter-frame movement of the target vehicle 3 in the range image 128, to the ground speed vector Vm of the host vehicle 1, which is generated by the vehicle exterior environment recognition device 120 based on the speed of the host vehicle 1, to derive the ground speed vector of the target vehicle 3, namely, the target speed vector Vs.

[0077] Next, the speed derivation unit 166 uses the target tangent 222, a tangent to the target path 220, which is a curve parallel to the host vehicle's path 210, at the position of the target vehicle 3, as the speed calculation axis and derives the target tangent velocity component Vt, which is the velocity component obtained by decomposing the target velocity vector Vs into the target tangent 222. The target tangent velocity component Vt can be expressed as Vs·cosθ using the angle θ formed between the target velocity vector Vs and the target tangent 222. The speed derivation unit 166 then deems the direction (sign) of the target tangent velocity component Vt to be the direction (sign) of the target velocity vector Vs. This allows the direction (sign) to be defined for the directionless target velocity vector Vs.

[0078] (Following control S208)

[0079] The following control unit 168 switches the following control according to the angle θ formed between the object velocity vector Vs and the object tangent line 222 .

[0080] Use again Figure 8 To explain, the object velocity vector Vs has an angle with respect to the object tangent line 222, which is a tangent to the object path 220. If the target vehicle 3 is traveling in the same direction as the host vehicle 1, the target velocity vector Vs of the target vehicle 3 is in the same direction as the target path 220. Therefore, the angle θ formed between the target velocity vector Vs and the object tangent line 222 should be smaller. On the other hand, if the target vehicle 3 cuts in on the path of the host vehicle 1, the angle θ formed between the target velocity vector Vs and the object tangent line 222 should be larger.

[0081] Therefore, if the angle θ formed between the object velocity vector Vs and the object tangent line 222 is within a predetermined angular range (e.g., ±45 degrees), the following control unit 168 performs following control for the target vehicle 3 based on the object velocity vector Vs itself. On the other hand, if the angle θ formed between the object velocity vector Vs and the object tangent line 222 is outside the predetermined angular range, the following control unit 168 performs following control for the target vehicle 3 based on the target tangent velocity component Vt, which is the velocity component of the object velocity vector Vs at the object tangent line 222.

[0082] Figure 9 and Figure 10 This is an explanatory diagram for explaining the following control. Thus, if the angle θ between the object velocity vector Vs and the object tangent 222 is outside the predetermined angle range, the following control unit 168 performs following control on the object vehicle 3 as the object of following control along the direction of the object tangent velocity component Vt. Specifically, Figure 9 As shown, following control unit 168 decomposes the target tangential velocity component Vt into the Z-axis 230 in the direction of travel of host vehicle 1 and the X-axis 232 perpendicular to the direction of travel, deriving velocity components Vz and Vx. Following control unit 168 then controls the speed of host vehicle 1 based on velocity component Vz to maintain a safe inter-vehicle distance.

[0083] As described above, when the target vehicle 3 cuts in on the path of the host vehicle 1 , the following control unit 168 can appropriately perform following control on the target vehicle 3 by reducing the speed of the host vehicle 1 based on the target tangential velocity component Vt.

[0084] Furthermore, if the angle θ between the object velocity vector Vs and the object tangent line 222 is within a predetermined angle range, the following control unit 168 performs following control of the object vehicle 3 along the direction of the object velocity vector Vs itself. Specifically, Figure 10 As shown, following control unit 168 decomposes the target velocity vector Vs into the Z-axis 230 and X-axis 232 of the travel direction of host vehicle 1, deriving velocity components Vz and Vx. Following control unit 168 then controls the speed of host vehicle 1 based on velocity component Vz to maintain a safe inter-vehicle distance.

[0085] Thus, when the target vehicle 3 is traveling in the same direction as the host vehicle 1 , even if the target vehicle 3 turns, the following control unit 168 does not abruptly change the speed of the host vehicle 1 based on the target speed vector Vs, and can perform smooth travel control.

[0086] It should be noted that although 45 degrees is listed here as the predetermined angle, it is not limited to this case. As long as it is possible to determine whether the target vehicle 3 is a vehicle to be followed traveling in the same direction of travel as the vehicle 1, it can be any angle selected from 10 to 45 degrees.

[0087] Since the predetermined angle is set to an angle that distinguishes vehicles traveling in the same direction as the host vehicle 1, the angle θ formed between the target velocity vector Vs of the host vehicle 3 and the target tangent 222 will not exceed the predetermined angle as long as the target vehicle 3 is traveling on the target travel path 220. In other words, the speed subject to following control will not experience jumps in the target velocity vector Vs and the target tangent velocity component Vt. Furthermore, even if the predetermined angle is exceeded, the following control unit 168 applies an LPF (low-pass filter) to the control operation to suppress sudden changes in the behavior of the host vehicle 1.

[0088] As described above, since it is determined whether the target vehicle 3 is traveling in the same direction as the host vehicle 1 and the speed of the following control is selected accordingly, appropriate following control can be achieved.

[0089] Also provided are a program for causing a computer to function as vehicle exterior environment recognition device 120, and a computer-readable storage medium such as a floppy disk, magneto-optical disk, ROM, CD, DVD, or BD storing the program. Here, the program refers to data processing means described in any language and / or description method.

[0090] While preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these embodiments. It should be understood that those skilled in the art may conceive of various modifications and variations within the scope of the claims, and such modifications and variations are also within the technical scope of the present invention.

[0091] For example, in the above-described embodiment, both the host vehicle path 210 and the target path 220 are approximated as circles represented by a radius R. However, the present invention is not limited to this, and they may be approximated as multi-order curves.

[0092] It should be noted that the steps of the vehicle exterior environment recognition process in this specification do not necessarily need to be processed in time series in the order described as a flowchart, and may include processing in parallel or by a subroutine.

[0093] Industrial availability

[0094] The present invention can be used in a vehicle exterior environment recognition device that follows a target vehicle that is located in the traveling direction of the vehicle.

Claims

1. A vehicle exterior environment recognition device, characterized in that: have: a travel path deriving unit that estimates the travel path of the host vehicle and derives a target travel path, the target travel path being the travel path of the host vehicle, the target travel path passing through the target vehicle that is the subject of following control and forming a parallel curve with the travel path of the host vehicle; a speed deriving unit that derives a target speed vector, the target speed vector being a speed vector of the target vehicle; as well as A following control unit, if the angle formed by the object velocity vector and the object tangent is within a predetermined angle range, decomposes the object velocity vector into the traveling direction of the host vehicle and a direction perpendicular to the traveling direction, derives the velocity component of the object velocity vector in the traveling direction of the host vehicle, and performs following control based on the velocity component of the object velocity vector in the traveling direction of the host vehicle; if the angle is outside the predetermined angle range, decomposes the velocity component of the object velocity vector at the object tangent, i.e., the object tangent velocity component, into the traveling direction of the host vehicle and a direction perpendicular to the traveling direction, derives the velocity component of the object tangent velocity component in the traveling direction of the host vehicle, and performs following control based on the velocity component of the object tangent velocity component in the traveling direction of the host vehicle, wherein the object tangent is a tangent of the object traveling path at the position of the object vehicle.

2. The vehicle exterior environment recognition device according to claim 1, characterized in that: The host vehicle travel path and the object travel path are represented as parts of concentric circles.

3. The vehicle exterior environment recognition device according to claim 1 or 2, characterized in that: The travel path derivation unit sets the host vehicle travel path as a straight line if a radius of a circle representing the host vehicle travel path is equal to or greater than a predetermined length.

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