Vehicle control device

Abstract

The objective of the present invention is to provide a vehicle control device capable of achieving smooth inter-vehicle distance control without losing recognition of lane dividing lines, and thus able to suppress discomfort felt by a driver. To this end, a vehicle control device 100 comprises a white line recognition auxiliary control unit 430 which, when a first straight line 811 from an external environment recognition unit installation point 810 based on the installation position of an external environment recognition unit 200 in the forward direction of a host vehicle 600 intersects with a leading vehicle 700, calculates the angle between second straight lines 851, 831 connecting the external environment recognition unit installation point 810 and a left end point 850 or a right end point 830 of the leading vehicle 700 obtained from the forward image and the first straight line 811 as a leading vehicle projection angle 800 and corrects the target inter-vehicle distance on the basis of the leading vehicle projection angle 800.

Description

Vehicle control device

[0001] The present invention relates to a vehicle control device that performs steering assistance so that a vehicle can travel in the center of a travel lane.

[0002] In vehicle control devices that provide steering assistance to enable the vehicle to travel in the center of the driving lane, it is common for the steering assistance control to be performed under acceleration / deceleration control using a function that maintains a constant distance from the vehicle in front.

[0003] In the prior art, a means has been considered that has a function to detect lane markings in the driving lane and a function to maintain a constant distance between the vehicle and the preceding vehicle, and that calculates the occlusion avoidance distance (white line recognition distance) at which the lane markings are no longer occluded when triggered by the preceding vehicle occluding the lane markings. By setting a limit so that the target value of the inter-vehicle distance between the vehicle and the preceding vehicle is not shorter than the occlusion avoidance distance, it becomes possible to drive while maintaining a distance at which the lane markings can always be detected during following driving (Patent Document 1).

[0004] JP 2009-134455 A

[0005] In recent years, the number of vehicle models equipped with LKA (Lane Keep Assist) and TJA (Traffic Jam Assist), which are functions that provide steering assistance to keep the vehicle in the center of the lane, has been increasing, and these systems are now being used in a wide range of vehicles, from ordinary passenger cars to trucks.

[0006] In particular, TJA operates simultaneously with adaptive cruise control (ACC), which controls acceleration and deceleration to maintain a constant distance from the vehicle ahead. This allows the vehicle to follow the vehicle ahead and maintain the center of the lane in situations where traffic congestion forces slower driving. However, because the vehicle ahead is controlled to have a shorter distance as the vehicle speed decreases, in situations where TJA is used, the distance to the vehicle ahead may become closer, causing the vehicle ahead to block lane markings. In such cases, there are systems that change the target of steering assistance from the center of the lane to the trajectory of the vehicle ahead and continue steering assistance. However, if the vehicle ahead deviates from its lane, the vehicle may end up following the vehicle ahead and traveling on an unintended route. Furthermore, because trucks do not have hoods, the distance between the vehicle ahead and a sensing device (e.g., a camera installed near the rearview mirror) is closer than in passenger cars, making lane markings more likely to be blocked.

[0007] To address this issue, we are considering an idea to improve the convenience of the function by predicting when a lane marking will be blocked by a preceding vehicle and controlling the distance between vehicles so that TJA can continue along the lane marking.

[0008] The prior art (Patent Document 1) has a lane marking detection function for the driving lane and an ACC function, and includes a means for detecting the occlusion avoidance distance (white line recognition distance) at which the lane markings are no longer obscured, triggered by the ACC's preceding vehicle blocking the lane markings. A limit is set so that the ACC target inter-vehicle distance does not become shorter than the occlusion avoidance distance, allowing the vehicle to travel while maintaining a distance at which the lane markings are always visible during ACC.

[0009] However, because the system determines the occlusion avoidance distance and limits the target inter-vehicle distance after the lane markings are occluded, the inter-vehicle distance may change suddenly, potentially causing an uncomfortable ride for the driver. Also, the target inter-vehicle distance changes depending on the shape, direction, and driving position of the preceding vehicle, and the amount of change varies depending on whether the lane markings can be detected, which may also cause discomfort to the driver.

[0010] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a vehicle control device that can reduce the discomfort felt by the driver by realizing smooth inter-vehicle distance control without losing recognition of lane markings.

[0011] In order to achieve the above object, the present invention provides a vehicle control device that includes an external environment recognition unit that captures an image in front of the host vehicle, a preceding vehicle detection unit that generates information about a preceding vehicle traveling in front of the host vehicle based on the forward image, and an inter-vehicle distance control unit that outputs acceleration / deceleration control instructions to maintain the inter-vehicle distance between the host vehicle and the preceding vehicle at a target inter-vehicle distance based on the information about the preceding vehicle. The vehicle control device further includes a white line recognition assistance control unit that, when a first line drawn in the straight direction of the host vehicle from an external environment recognition unit installation point based on the installation position of the external environment recognition unit intersects with the preceding vehicle, calculates the angle formed by the first line and a second line connecting the external environment recognition unit installation point and the left end point or the right end point of the preceding vehicle obtained from the forward image as a preceding vehicle projection angle, and corrects the target inter-vehicle distance based on the preceding vehicle projection angle.

[0012] According to the vehicle control device of the present invention, it is possible to prevent the driver from losing track of lane markings and to achieve smooth inter-vehicle distance control, thereby reducing the sense of discomfort felt by the driver.

[0013] Functional block diagram of a vehicle control device. Diagram showing the projection angle of a preceding vehicle. Diagram showing an image in front of the host vehicle. Diagram showing the projection angle of a preceding vehicle when the direction of the preceding vehicle changes. Diagram showing the left projection angle and the right projection angle of a preceding vehicle. Flowchart showing the processing of a modified example of a white line recognition assistance control unit. Diagram showing the difference in white line detection depending on lane width. Diagram showing the characteristics of the target inter-vehicle distance for ACC. Functional block diagram of a modified example of a vehicle control device.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are used to designate the same components, and redundant description will be omitted.

[0015] 1 is a functional block diagram of a vehicle control device 100 according to this embodiment. The vehicle control device 100 is mounted on a host vehicle 600 (shown in FIG. 2) and controls the host vehicle 600. The vehicle control device 100 includes a calculation device such as a CPU, storage devices such as a ROM and RAM, an input / output interface for inputting and outputting signals to and from external devices, and the vehicle control device 100 realizes each functional unit by executing a program stored in the ROM or the like.

[0016] The vehicle control device 100 includes an inter-vehicle distance control unit 400 and a steering control unit 500. The inter-vehicle distance control unit 400 has a target inter-vehicle distance setting unit 410, a target acceleration calculation unit 420, and a white line recognition assistance control unit 430. The steering control unit 500 has a target steering angle setting unit 510 and a steering torque calculation unit 520.

[0017] The external environment recognition unit 200 is set in the host vehicle 600 and includes a preceding vehicle detection unit 210 and a lane marking detection unit 220. Note that the preceding vehicle detection unit 210 or the lane marking detection unit 220 may be provided as a functional unit independent of the external environment recognition unit 200. The preceding vehicle detection unit 210 outputs the distance and relative speed to the preceding vehicle 700 and the trajectory of the preceding vehicle 700 (preceding vehicle information) based on an image ahead of the host vehicle (shown in FIG. 3) captured by the external environment recognition unit 200. The lane marking detection unit 220 detects lane markings 880 (shown in FIG. 2) of the lane 870 (shown in FIG. 2) in which the host vehicle 600 is traveling, and outputs the position and angle (attitude) of the host vehicle 600 relative to the lane markings 880.

[0018] Target inter-vehicle distance setting unit 410 sets a target inter-vehicle distance based on the speed of host vehicle 600 obtained from wheel speed sensor 300. Target acceleration calculation unit 420 calculates a target acceleration required for following the target inter-vehicle distance based on the target inter-vehicle distance and the relative speed with preceding vehicle 700 (shown in FIG. 2 ) obtained from preceding vehicle detection unit 210, and outputs the engine torque and brake work required to achieve the target acceleration to engine control unit 310 and brake actuator 320, respectively.

[0019] Target steering angle setting unit 510 calculates a target steering angle required to follow preceding vehicle 700 or to travel in the center of lane 870, based on the trajectory of preceding vehicle 700 obtained from preceding vehicle detection unit 210 and the position and angle (attitude) of host vehicle 600 relative to lane markings 880 obtained from marking detection unit 220. Steering torque calculation unit 520 calculates the steering torque required to achieve the target steering angle, and outputs the calculated torque to steering actuator 330.

[0020] The control by the steering control unit 500 to keep the vehicle in the center of the lane 870 is carried out simultaneously with the control by the inter-vehicle distance control unit 400 to maintain a constant distance from the preceding vehicle, and therefore, the control is generally carried out under the condition that the control by the inter-vehicle distance control unit 400 is in progress. However, when traveling at low speed due to congestion or the like, the distance between the vehicle and the preceding vehicle 700 becomes small, and the preceding vehicle 700 blocks the lane markings 880, which makes it impossible for the lane marking detection unit 220 to calculate the position and angle (attitude) of the host vehicle 600 relative to the lane markings 880. As a result, it may become impossible to continue the control to keep the host vehicle in the center of the lane 870.

[0021] To address this issue, the prior art (Patent Document 1) proposes a method that uses the preceding vehicle 700's occlusion of the lane marking 880 as a trigger to detect the occlusion avoidance distance at which the lane marking 880 is no longer occluded, sets a limit so that the target inter-vehicle distance does not become shorter than the occlusion avoidance distance, and allows the vehicle to travel while maintaining a distance at which the lane marking 880 is always visible. However, as described above, because the occlusion avoidance distance is determined and the target inter-vehicle distance is limited after the lane marking 880 is occluded once, the inter-vehicle distance may change suddenly, potentially causing an uncomfortable ride for the driver. In addition, the target inter-vehicle distance changes depending on the shape, orientation, and driving position of the preceding vehicle 700, and the amount of change varies depending on whether the lane marking 880 can be detected, which may also cause the driver to feel uncomfortable.

[0022] Therefore, in this embodiment, in order to achieve smooth inter-vehicle distance control without losing recognition of the lane markings 880 and to provide control that is less uncomfortable for the driver, instead of using feedback control that determines a control value in response to occlusion, continuous inter-vehicle distance control is performed using feedforward control regardless of whether the current situation ahead of the vehicle is occluded or not.In this way, the white line recognition assistance control unit 430 calculates the preceding vehicle projection angle 800 (shown in FIG. 2) from the preceding vehicle information obtained from the preceding vehicle detection unit 210, and outputs an additive term to the target inter-vehicle distance setting unit 410 to correct the target inter-vehicle distance.

[0023] Next, the control performed by the white line recognition assistance control unit 430 will be described with reference to FIG. 2 . FIG. 2 is a diagram illustrating a state in which the host vehicle 600 equipped with the vehicle control device 100 is following a preceding vehicle 700, and illustrates how the preceding vehicle projection angle 800 is calculated. In the white line recognition assistance control unit 430, the point closest to the host vehicle 600 where the preceding vehicle 700 intersects with a straight line extending from an external environment recognition unit installation point 810, where the external environment recognition unit 200 is installed, in the direction of travel of the host vehicle 600, is defined as the preceding vehicle intersection 820. For example, if the external environment recognition unit 200 is a monocular camera, the center position of the lens may be set as the external environment recognition unit installation point 810. If the external environment recognition unit 200 is a stereo camera, the midpoint between both lenses may be set as the external environment recognition unit installation point 810. Next, the right edge of the preceding vehicle 700 detected from the image ahead of the host vehicle is defined as the preceding vehicle right edge point 830.

[0024] The preceding vehicle projection angle 800 is the angle formed at the external environment recognition unit installation point 810, which is the vertex of a triangle formed by connecting the external environment recognition unit installation point 810, the preceding vehicle intersection 820, and the preceding vehicle right end point 830.

[0025] FIG. 2 is a bird's-eye view of the host vehicle 600 and the preceding vehicle 700 viewed from above. In contrast, FIG. 3 shows an image of the preceding vehicle projection angle 800 in the host vehicle forward image captured by the external environment recognition unit 200. As in FIG. 2 , a preceding vehicle intersection 820 and a preceding vehicle right end point 830 can be set for the preceding vehicle 700, and the lateral spread (N [pixels]) between the preceding vehicle intersection 820 and the preceding vehicle right end point 830 corresponds to the preceding vehicle projection angle 800. The preceding vehicle projection angle 800 is a parameter that represents the lateral occupancy rate of the preceding vehicle 700 in the host vehicle forward image. Therefore, the larger this value, the more likely it is that the preceding vehicle 700 will block the lane markings 880, making it impossible for the lane marking detection unit 220 to detect the lane markings 880. While the preceding vehicle 700 in FIGS. 2 and 3 is depicted as an ordinary passenger car, the preceding vehicle 700 may also be, for example, a motorcycle or a large truck. Therefore, if the following distance is the same, a large truck will have a greater lateral spread than a motorcycle, which will result in a larger preceding vehicle projection angle 800 and a high possibility that the lane markings 880 will not be detected. Therefore, in order to detect the lane markings 880, it is necessary to maintain a longer following distance for the ACC than usual.

[0026] There is a concern that the value of preceding vehicle projection angle 800 may vary due to vehicle vibrations while driving. To prevent unintended changes in the value of the target inter-vehicle distance in the subsequent stage, filtering to remove noise and limiting the amount of change per time are performed to suppress sudden changes in the value of preceding vehicle projection angle 800, thereby enabling smooth acceleration / deceleration control that does not cause discomfort to the driver.

[0027] When the unit of the preceding vehicle projection angle 800 is [deg], the white line recognition assist control unit 430 uses a correction gain [m / deg], which is a control parameter by which the preceding vehicle projection angle 800 is multiplied, to calculate an additive term for the target inter-vehicle distance according to the following equation (1): Additive term = Correction gain × Preceding vehicle projection angle (1) The additive term calculated in this way is a value proportional to the preceding vehicle projection angle 800, and changes continuously in accordance with the occupancy rate of the driver's field of view. The additive term is referenced by the target inter-vehicle distance setting unit 410.

[0028] Next, the target inter-vehicle distance setting unit 410 of this embodiment will be described. The target inter-vehicle distance [m] for ACC is generally expressed using the vehicle speed [m / s] and the inter-vehicle time [s], as shown in the following equation (2): Target inter-vehicle distance = Vehicle speed × Inter-vehicle time (2) In this embodiment, the target inter-vehicle distance calculated using equation (2) is calculated using the following equation (3) by adding an additive term obtained by the white line recognition assist control unit 430: Target inter-vehicle distance = Vehicle speed × Inter-vehicle time + Additive term (3) Calculating the target inter-vehicle distance using equation (3) ensures the necessary inter-vehicle time for following the preceding vehicle 700 while maintaining a distance that matches the driver's field of view. Furthermore, it becomes possible to continue driving while maintaining the necessary inter-vehicle distance for detecting lane markings 880, thereby improving the stability of steering control. In contrast, the correction of the target inter-vehicle distance expressed by equation (3) may be performed only during control by the steering control unit 500 (TJA), or may be performed even when not under control. For example, it is also possible to allow the driver to select whether or not to perform the correction when the steering control unit 500 (TJA) is not under control.

[0029] Next, the target acceleration calculation unit 420 calculates the deviation (distance deviation) between the inter-vehicle distance obtained from the preceding vehicle detection unit 210 and the target inter-vehicle distance obtained from the target inter-vehicle distance setting unit 410. Furthermore, the relative speed between the host vehicle 600 and the preceding vehicle 700 is calculated by time-differentiating the inter-vehicle distance obtained from the preceding vehicle detection unit 210. Based on the distance deviation and relative speed thus obtained, the target acceleration (target acceleration) to be generated in the host vehicle is calculated. This calculation is performed such that if the inter-vehicle distance is closer to the target inter-vehicle distance, the host vehicle is decelerated more strongly, and if the inter-vehicle distance is farther from the target inter-vehicle distance, the host vehicle is accelerated more strongly. If the relative speed is approaching faster, the host vehicle is decelerated more strongly, and if the relative speed is receding faster, the host vehicle is accelerated more strongly. Furthermore, if the host vehicle continues to be controlled using the calculated target acceleration, the value of the target acceleration is adjusted so that the distance deviation and the relative speed simultaneously become zero. This configuration enables control to appropriately accelerate and decelerate the vehicle in accordance with the behavior of the preceding vehicle 700, while preventing unnecessary acceleration and deceleration.

[0030] Next, one advantage of using the preceding vehicle projection angle 800 in the calculations of the white line recognition assist control unit 430 will be described. FIG. 4 shows the preceding vehicle projection angle 800 when the orientation of the preceding vehicle 700 in FIG. 2 changes. For example, if the inter-vehicle distances in FIGS. 2 and 3 are the same, the preceding vehicle projection angle 800 in FIG. 3, where the orientation of the preceding vehicle 700 has changed, is larger, and a correction is made to increase the target inter-vehicle distance. As shown in Equations (1) and (3), the correction of the target inter-vehicle distance acts linearly with the preceding vehicle projection angle 800. This prevents a sudden change in the inter-vehicle distance and is therefore not expected to adversely affect ride comfort. For a driver, an increase in the area blocked by the preceding vehicle 700 in front of the vehicle can lead to discomfort, but increasing the distance to reduce the blocked area can alleviate this discomfort. For example, if this is a change in direction due to the preceding vehicle 700 changing lanes, by continuing to detect the lane markings 880, it is possible to prevent the vehicle 600 from deviating from the lane markings 880 by following the preceding vehicle 700.

[0031] Up to this point, the preceding vehicle projection angle 800 has been defined as the angle formed at the external environment recognition unit installation point 810, which is the apex of a triangle formed by connecting the external environment recognition unit installation point 810, the preceding vehicle intersection 820, and the preceding vehicle's right end point 830. However, it is also possible to take the left end point of the preceding vehicle into consideration. In FIG. 5 , a preceding vehicle's left end point 850 is added to FIG. 2 , and the angle formed at the external environment recognition unit installation point 810, which is the apex of a triangle formed by connecting the external environment recognition unit installation point 810, the preceding vehicle intersection 820, and the preceding vehicle's left end point 850, is defined as the preceding vehicle's left projection angle 860. Accordingly, the preceding vehicle projection angle 800 has been replaced with the preceding vehicle's right projection angle 840. The correction of the target inter-vehicle distance in Equation (3) can be transformed into Equation (4) below using the preceding vehicle's right projection angle 840 and the preceding vehicle's left projection angle 860. Target inter-vehicle distance = vehicle speed × inter-vehicle time + right correction gain × preceding vehicle right projection angle + left correction gain × preceding vehicle left projection angle (4) In equation (4), the correction gain is divided into right (right correction gain) and left (left correction gain), and the additive term is calculated by multiplying the preceding vehicle right projection angle and the preceding vehicle left projection angle by each of these and adding them together. If only the preceding vehicle right projection angle 840 is used as in FIG. 2 and equation (3), the target inter-vehicle distance will change if, for example, the preceding vehicle 700 sways left or right, or if the host vehicle 600 sways left or right, which may cause the driver to feel uncomfortable. Basically, when the preceding vehicle 700 approaches one of the lane markings 880, the preceding vehicle right projection angle 840 and the preceding vehicle left projection angle 860 increase and the other decreases, respectively. Therefore, the calculation of equation (4) can prevent changes in the target inter-vehicle distance. Furthermore, since it becomes possible to more precisely perform corrections according to the occupancy rate of the preceding vehicle 700 in the driver's field of vision, it is possible to provide control that is less uncomfortable for the driver.

[0032] Next, modified examples of the white line recognition assist control unit 430 depending on the type of lane marking 880 will be described. The lane marking 880 may be a solid line or a dashed line. The line detection distance required for the lane marking detection unit 220 to calculate the position and angle (attitude) of the host vehicle relative to the lane marking 880 is longer for dashed lines than for solid lines, so in the case of dashed lines, control is provided to ensure a larger inter-vehicle distance. When the right side is a solid line and the left side is a dashed line as shown in FIG. 5 , this is handled by weighting the preceding vehicle left projection angle 860 more heavily than the preceding vehicle right projection angle 840.

[0033] FIG. 6 is a flowchart showing a modified example of the processing of the white line recognition assistance control unit 430. In FIG. 6 , first, in step 900, it is determined whether the white line on the right side is a solid line or a broken line. Similarly, in step 910, it is determined whether the white line on the left side is a solid line or a broken line. Steps 900 and 910 may be performed within the lane marking detection unit 220. Next, in step 920, based on the detection result of step 900, it is determined whether the white line on the right side is a broken line. If the determination result is true, the process proceeds to step 930. If the determination result is false, the process proceeds to step 940. In step 930, the right correction gain in equation (4) is increased compared to the case where the white line is a solid line. Similarly, in step 940, based on the detection result of step 910, it is determined whether the white line on the left side is a broken line. If the determination result is true, the process proceeds to step 950. If the determination result is false, the process ends. In step 950, the left correction gain in equation (4) is increased compared to when the line is solid, and the flow ends. By correcting the target inter-vehicle distance in equation (4) according to the flowchart in FIG. 6, the stability of white line detection can be improved even when the line is broken. Furthermore, by preventing the inter-vehicle distance from being too long when the line is not broken, the sense of discomfort can be reduced. In this way, optimizing the additional value of the target inter-vehicle distance depending on the situation helps prevent excessive correction.

[0034] However, when correcting the target inter-vehicle distance in this manner, it is necessary to suppress changes in the target inter-vehicle distance when the line changes from a broken line to a solid line or from a solid line to a broken line. Therefore, for example, hysteresis can be provided to prevent frequent changes in the determination in steps 900 and 910. Furthermore, once it is determined that the line has transitioned from a solid line to a broken line, processing can be added such that the determination of a transition from a broken line to a solid line is not made again for a certain period of time. Alternatively, a limit can be set on the amount of change in the increase in the correction gain in steps 930 and 950 to prevent a sudden change in the correction amount.

[0035] When correcting the inter-vehicle distance, it is also effective to consider the width of the lane in which the vehicle is currently traveling. As shown in FIG. 7 , under the same inter-vehicle distance conditions as the preceding vehicle 700, the narrower the lane width, the shorter the detection distance required for the lane marking detection unit 220 to calculate the position and angle (attitude) of the host vehicle 600 relative to the lane marking 880. Therefore, by adding the lane width as an input, for example, if the lane width is smaller than a predetermined value, it is possible to increase the correction gain in equation (4) so ​​that the inter-vehicle distance can be longer than when the lane width is wider. This is expected to improve the stability of white line detection on narrow roads and prevent the inter-vehicle distance from being too long when the lane width is wide, thereby reducing the sense of discomfort.

[0036] In a traffic jam, the vehicle may come to a complete stop. However, the change in inter-vehicle distance when stopped due to the control of this embodiment may cause the driver to feel uncomfortable. FIG. 8 is a graph with vehicle speed on the horizontal axis and the ACC target inter-vehicle distance on the vertical axis. The ACC inter-vehicle distance can be set to any level by the driver. For example, there are three levels: Short, Middle, and Long, and they are set according to the characteristics shown in FIG. 8. The same value is obtained when the vehicle speed is near 0, which indicates that the inter-vehicle distance when stopping is the same. Since the same result must be achieved even when the control of this embodiment is implemented, it is possible to gradually decrease the correction term in Equation (4) to zero when traveling at extremely low speeds, for example, when the vehicle speed is less than 5 km / h. This prevents the inter-vehicle distance from becoming too long when stopped, which leads to suppressing the driver's discomfort.

[0037] Target steering angle setting unit 510 of steering control unit 500 calculates a target steering angle required to follow leading vehicle 700 or to travel in the center of lane 870, based on the trajectory of leading vehicle 700 obtained from leading vehicle detection unit 210, the curvature of lane markings 880 obtained from lane marking detection unit 220, and the position and angle (posture) of the host vehicle relative to lane markings 880. The target steering angle required to travel in the center of lane 870 is calculated as the sum of a component for traveling along the curvature, a component for moving the position of host vehicle 600 to the center of lane 870, and a component for aligning the angle of host vehicle 600 with lane 870.

[0038] A steering torque calculation unit 520 that calculates the steering torque required to achieve the target steering angle performs feedback control, such as PID control, to reduce the deviation between the target steering angle and the current steering angle to zero, and calculates the steering torque.

[0039] When traveling at extremely low speeds and without seeing white lines on either side, in order to prevent the generation of steering torque that would lead to a lane change and prevent an unintended lane change, it is also possible to request the steering torque calculation unit 520 of the steering control unit 500 to maintain the control amount of the steering torque currently being used for control when steering control is being performed in accordance with the traveling trajectory of the preceding vehicle 700 without detecting white lines and the traveling speed of the host vehicle 600 or the preceding vehicle 700 is slower than a certain speed. Figure 9 shows the control from the white line recognition assistance control unit 430 to the steering torque calculation unit 520 in the block diagram of Figure 1 with a dashed line. Furthermore, instead of maintaining the control amount, it is also possible to gradually reduce the steering amount to zero or suppress the amount of change.

[0040] The object of this control is not limited to the steering torque, but can also be a target yaw angle or a target steering angle instruction, for example, target steering angle setting unit 510.

[0041] (Summary) In this embodiment, in a vehicle control device 100 including an external environment recognition unit 200 that captures an image ahead of the host vehicle 600, a preceding vehicle detection unit 210 that generates information about a preceding vehicle 700 traveling ahead of the host vehicle 600 based on the forward image, and a vehicle distance control unit 400 that outputs an acceleration / deceleration control instruction to maintain the inter-vehicle distance between the host vehicle 600 and the preceding vehicle 700 at a target inter-vehicle distance based on the information about the preceding vehicle 700, When a first line 811 drawn in the straight-ahead direction of the host vehicle 600 from an external environment recognition unit installation point 810 based on the image data intersects with a preceding vehicle 700, the angle formed by the first line 811 and a second line 851, 831 connecting the external environment recognition unit installation point 810 and a left end point 850 or a right end point 830 of the preceding vehicle 700 obtained from the forward image is calculated as a preceding vehicle projection angle 800, and the white line recognition assistance control unit 430 corrects the target inter-vehicle distance based on the preceding vehicle projection angle 800.

[0042] According to the present embodiment configured as described above, the target inter-vehicle distance is corrected in accordance with the preceding vehicle projection angle 800, which corresponds to the proportion of the preceding vehicle 700 that the preceding vehicle 700 occupies in the driver's field of vision (field of vision occupancy), thereby preventing loss of awareness of the lane markings 880 and achieving smooth inter-vehicle distance control, thereby minimizing the discomfort felt by the driver.

[0043] Furthermore, the vehicle control device 100 in this embodiment includes a dividing line detection unit 220 that generates, based on the forward image, driving lane information, which is information about the lane 870 in which the host vehicle 600 is traveling, and a steering control unit 500 that outputs steering torque for following the lane 870, based on the driving lane information and information about the preceding vehicle 700, and the white line recognition assistance control unit 430 makes a correction to increase the target inter-vehicle distance so that the dividing line detection unit 220 can generate the driving lane information that enables the steering control unit 500 to continue control of the lane 870. This makes it possible for the steering control unit 500 to reliably continue control of the lane 870.

[0044] Furthermore, the vehicle control device 100 in this embodiment includes a lane marking detection unit 220 that generates, based on the forward image, driving lane information, which is information about the lane 870 in which the host vehicle 600 is traveling. The lane marking detection unit 220 identifies the type of lane marking 880 of the lane 870 based on the driving lane information. The white line recognition assistance control unit 430 corrects the target inter-vehicle distance to be longer when the lane marking 880 is a dashed line than when the lane marking 880 is a solid line. This makes it possible to stably detect dashed lane markings 880.

[0045] Furthermore, the vehicle control device 100 in this embodiment includes a lane marking detection unit 220 that generates, based on the forward image, driving lane information, which is information about the lane 870 in which the host vehicle 600 is traveling. The lane marking detection unit 220 identifies the width of the lane 870 based on the driving lane information, and the white line recognition assistance control unit 430 corrects the target inter-vehicle distance to be longer if the width of the lane 870 is smaller than a predetermined value. This makes it possible to stably detect lane markings 880 even in narrow lanes 870.

[0046] Furthermore, in this embodiment, the white line recognition assistance control unit 430 corrects the target inter-vehicle distance to be shorter in accordance with the traveling speed when the traveling speed of the host vehicle 600 or the preceding vehicle 700 is lower than a predetermined value. This prevents the inter-vehicle distance from becoming too long when the vehicle is stopped, thereby further reducing the discomfort felt by the driver.

[0047] Furthermore, the white line recognition assistance control unit 430 in this embodiment calculates the preceding vehicle projection angle 800 formed by the first line 811 and a second line 851 connecting the external environment recognition unit installation point 810 and the left end point 850 of the preceding vehicle 700 as the preceding vehicle left projection angle 860, calculates the preceding vehicle projection angle 800 formed by the first line 811 and a second line 831 connecting the external environment recognition unit installation point 810 and the right end point 830 of the preceding vehicle 700 as the preceding vehicle right projection angle 840, and corrects the target inter-vehicle distance based on each of the preceding vehicle left projection angle 860 and the preceding vehicle right projection angle 840. This makes it possible to more precisely correct the target inter-vehicle distance according to the field of view occupancy rate of the preceding vehicle 700, thereby further reducing the sense of discomfort felt by the driver.

[0048] Furthermore, the vehicle control device 100 in this embodiment includes a lane marking detection unit 220 that generates, based on the forward image, driving lane information, which is information about the lane 870 in which the host vehicle 600 is traveling, and a steering control unit 500 that outputs a steering torque to follow the lane 870 or the preceding vehicle 700, based on the driving lane information and information about the preceding vehicle 700. When the lane marking detection unit 220 does not detect a lane marking 880 on the lane 870 and the traveling speed of the host vehicle 600 or the preceding vehicle 700 is lower than a predetermined value, the steering control unit 500 outputs a steering torque to follow the preceding vehicle 700. This makes it possible to prevent unintentional lane changes when traveling at an extremely low speed and when white lines on both sides cannot be seen.

[0049] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and can be modified and implemented in various ways. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the described configurations.

[0050] 100... Vehicle control device, 200... External environment recognition unit, 210... Leading vehicle detection unit, 220... Marking line detection unit, 300... Wheel speed sensor, 310... Engine control unit, 320... Brake actuator, 330... Steering actuator, 400... Inter-vehicle distance control unit, 410... Target inter-vehicle distance setting unit, 420... Target acceleration calculation unit, 430... White line recognition assistance control unit, 500... Steering control unit, 510... Target steering angle setting unit determination unit, 520...steering torque calculation unit, 600...host vehicle, 700...preceding vehicle, 800...preceding vehicle projection angle, 810...external environment recognition unit installation point, 811...first straight line, 820...preceding vehicle intersection, 830...preceding vehicle right end point, 831...second straight line, 840...preceding vehicle right projection angle, 850...preceding vehicle left end point, 851...second straight line, 860...preceding vehicle left projection angle, 870...lane (traffic lane), 880...lane dividing line, 900 to 950...steps.

Claims

1. In a vehicle control device comprising an external recognition unit that captures a front image of the host vehicle, a preceding vehicle detection unit that generates information on a preceding vehicle traveling in front of the host vehicle based on the front image, and a inter-vehicle distance control unit that outputs an acceleration / deceleration control instruction for maintaining the inter-vehicle distance between the host vehicle and the preceding vehicle at a target inter-vehicle distance based on the information on the preceding vehicle, when a first straight line drawn in the straight-ahead direction of the host vehicle from an external recognition unit installation point based on the installation position of the external recognition unit intersects the preceding vehicle, an angle formed by a second straight line connecting the external recognition unit installation point and the left end point or the right end point of the preceding vehicle obtained from the front image and the first straight line is calculated as a preceding vehicle projection angle, and a white line recognition assist control unit that corrects the target inter-vehicle distance based on the preceding vehicle projection angle is provided. A vehicle control device characterized by this.

2. In the vehicle control device according to claim 1, a lane marking detection unit that generates lane information on the lane in which the host vehicle is traveling, which is lane information on the front image, and a steering control unit that outputs a steering torque for following the lane based on the lane information and the information on the preceding vehicle are provided. The white line recognition assist control unit corrects the target inter-vehicle distance to be longer so that the lane marking detection unit can generate the lane information in which the steering control unit can continue control with respect to the lane. A vehicle control device characterized by this.

3. In the vehicle control device according to claim 1, a lane marking detection unit that generates lane information on the lane in which the host vehicle is traveling, which is lane information on the front image, is provided. The lane marking detection unit identifies the type of the lane marking of the lane based on the lane information. The white line recognition assist control unit corrects the target inter-vehicle distance to be longer when the type of the lane marking is a broken line than when the type of the lane marking is a solid line. A vehicle control device characterized by this.

4. In the vehicle control device according to claim 1, a lane marking detection unit that generates lane information on the lane in which the host vehicle is traveling, which is lane information on the front image, is provided. The lane marking detection unit identifies the width of the lane based on the lane information. The white line recognition assist control unit corrects the target inter-vehicle distance to be longer when the width of the lane is smaller than a predetermined value. A vehicle control device characterized by this.

5. In the vehicle control device according to claim 1, the white line recognition assist control unit corrects the target inter-vehicle distance to be shorter according to the running speed when the running speed of the host vehicle or the preceding vehicle is less than a predetermined value. A vehicle control device characterized by that.

6. In the vehicle control device according to claim 1, the white line recognition assist control unit calculates the preceding vehicle projection angle formed by the first straight line and the second straight line connecting the installation point of the external recognition unit and the left end point of the preceding vehicle as the preceding vehicle left projection angle, and calculates the second straight line connecting the installation point of the external recognition unit and the right end point of the preceding vehicle and the first straight line. The preceding vehicle projection angle formed is calculated as the preceding vehicle right projection angle, and the target inter-vehicle distance is corrected based on each of the preceding vehicle left projection angle and the preceding vehicle right projection angle. A vehicle control device characterized by that.

7. In the vehicle control device according to claim 1, a lane line detection unit that generates running lane information, which is information on the lane in which the host vehicle is running, based on the front image, and based on the running lane information and the information on the preceding vehicle, A steering control unit that outputs a steering torque for following the lane or the preceding vehicle is provided. When the lane line detection unit does not detect the lane line of the lane and the running speed of the host vehicle or the preceding vehicle is less than a predetermined value, the steering control unit outputs a steering torque for following the preceding vehicle. A vehicle control device characterized by that.

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