JP2017184012A - Drive support method and drive support apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive support method and a drive support apparatus, which enable easy grasp of a condition of a front wheel and that of a road.SOLUTION: A drive support apparatus includes an image generation circuit 20 in which a condition determination part 21 determines whether to start display processing in the drive support apparatus on the basis of a given condition. Plural cameras 10 are disposed in a vehicle so that a field angle includes a travel road boundary on one side of the vehicle. An image conversion part 22 converts from output signals of the plural cameras into an image that captures boundary of a travel road and front and rear wheels, and of which a size ratio of a front wheel to a rear wheel is larger than a ratio in an actual space, so that a display image generation part 24 generates a display image, and a display 30 displays the display image.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a driving support method and a driving support device that support a driver's driving operation on a vehicle.

  A technique for assisting the driving operation of the driver on a narrow road by displaying an image around the vehicle is known (see Patent Document 1). In such a technique, when an occupant performs a driving operation on a narrow road or the like, an image overlooking the vehicle is generated, and the generated image is displayed so that an interval between the vehicle and the road boundary can be grasped.

JP 2004-159186 A

  However, since the conventional technology displays an image in which the vehicle is viewed in the vertical direction, it is difficult for the driver to grasp the situation of the front wheels that determine the traveling direction of the vehicle and the situation of the surrounding road from the image. In some cases, it was difficult to drive.

  In view of the above problems, an object of the present invention is to provide a driving support method and a driving support device that can easily grasp the front wheel and road conditions.

  The image generation circuit reflects the boundary of the road and the front and rear wheels of the vehicle from a camera arranged on the vehicle so that the boundary of the road on one side of the vehicle is included in the angle of view, and the size of the front wheel relative to the rear wheel A display image having a larger ratio than that in the real space is generated, and the display image is displayed on the display.

  According to the present invention, there is provided a driving support method and a driving support device capable of easily grasping the situation of the front wheels and the road by displaying an image in which the ratio of the size of the front wheels to the rear wheels is larger than the ratio in the real space. Can be provided.

FIG. 1 is a block diagram illustrating a basic configuration of a driving support apparatus according to an embodiment of the present invention. FIG. 2 is an example of a top view of a vehicle equipped with the driving support apparatus according to the embodiment of the present invention. FIG. 3 is a diagram illustrating the positional relationship with the virtual viewpoint in the side view of the vehicle. FIG. 4 is a diagram for explaining the positional relationship between the virtual viewpoint and the projection plane, using a perspective view of the vehicle. FIG. 5 is an example illustrating a display image of the driving support apparatus according to the embodiment of the present invention. FIG. 6 is a diagram illustrating a display image when the entire front wheel and rear wheel on one side are shown. FIG. 7 is a diagram illustrating a display image when the steering angle is zero. FIG. 8 is a flowchart for explaining an example of the driving support method according to the embodiment of the present invention. FIG. 9 is an example illustrating an image of a vehicle viewed from the vertical direction. FIG. 10 is a diagram illustrating a display image when the front side of the vehicle is upward.

  Embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals, and redundant description is omitted.

(Drive assist device)
As shown in FIG. 1, the driving support apparatus according to the embodiment of the present invention includes a camera 10, an image generation circuit 20, a display 30, a vehicle sensor 40, and an input interface (I / F) 50. .

  As shown in FIG. 2, the camera 10 includes, for example, a front camera 11 mounted on the front end of the vehicle A, a side camera 12 mounted on the left end of the vehicle A, such as a door mirror on the left side of the vehicle A, A rear camera 13 mounted on the rear end of A.

  The front camera 11, the side camera 12, and the rear camera 13 are, for example, wide-angle cameras having an angle of view of about 180 °. The front camera 11 photographs the front of the vehicle A. The side camera 12 captures the left side of the vehicle A. The rear camera 13 photographs the rear of the vehicle A. The front camera 11, the side camera 12, and the rear camera 13 are arranged such that the added angle of view includes at least the left side (opposite side of the driver's seat) area of the road surface surrounding the vehicle A. . The side camera 12 may be two cameras mounted on the left and right sides. In this case, the front camera 11, the side camera 12, and the rear camera 13 are arranged so that the added angle of view includes a road surface area surrounding the vehicle A. The front camera 11, the side camera 12, and the rear camera 13 output an output signal indicating the captured image to the image generation circuit 20.

  The vehicle sensor 40 includes a vehicle speed sensor 41 and a rudder angle sensor 42. The vehicle speed sensor 41 detects the speed of the vehicle A and outputs it to the image generation circuit 20 as the vehicle speed. The steering angle sensor 42 detects the steering angle of the vehicle A by detecting the rotation angle of the steering shaft of the vehicle A, for example, and outputs it to the image generation circuit 20.

  The input I / F 50 is an input device that receives an operation by a passenger and inputs a signal corresponding to the operation to the image generation circuit 20. As the input I / F 50, various input devices such as various switches of the vehicle A that can be operated by a passenger of the vehicle A and a touch panel display can be adopted.

  The display 30 is a display device that displays a display image generated by the image generation circuit 20. The display 30 may be configured integrally with the input I / F 50 as a touch panel display.

  The image generation circuit 20 includes a condition determination unit 21, an image conversion unit 22, a virtual image generation unit 23, a display image generation unit 24, and an output processing unit 25 as a logical structure. The image generation circuit 20 can be configured by, for example, a microcomputer including a central processing unit (CPU), a memory, an input / output I / F, and the like. In this case, the microcomputer functions as the image generation circuit 20 by executing a computer program (image generation program) necessary for arithmetic processing by the image generation circuit 20. Each unit constituting the image generation circuit 20 may be configured by integral hardware or may be configured by separate dedicated hardware. The image generation circuit 20 may also be used as an electronic control unit (ECU) used for other control related to the vehicle A.

  The condition determination unit 21 determines whether to start display processing in the driving support apparatus according to the embodiment of the present invention based on a predetermined condition. For example, the condition determination unit 21 determines to start the display process when the vehicle A turns to the left while the left road boundary of the vehicle A is within a predetermined distance range from the vehicle A. The condition determination unit 21 may acquire information related to the travel route of the vehicle A from a navigation device or the like, and may determine that the display process is started when the road width of the travel route is equal to or less than a threshold value.

  In addition, the condition determination unit 21 may determine to start the display process in response to an occupant's operation on the input I / F 50 such as a dedicated switch. For example, the condition determination unit 21 may determine to start the display process in conjunction with the operation of the direction indicator. Alternatively, the condition determination unit 21 may determine to start the display process based on information on the operation of the direction indicator and the travel route.

  As shown in FIG. 3, the image conversion unit 22 converts an image (raw image data) acquired from the output signal of each camera 10 with distortion correction so that the image can be seen from the virtual viewpoint P. Since each camera 10 is a wide-angle camera, an image (raw image data) acquired from the output signal of each camera 10 has distortion compared to real space. The virtual viewpoint P is set in front of and above the front wheel Ba of the vehicle A. The line-of-sight direction Q from the virtual viewpoint P is backward and downward. That is, the image converted by the image conversion unit 22 is an image that is viewed from the virtual viewpoint P in the backward and downward direction.

  As shown in FIG. 4, for example, the image conversion unit 22 uses the raw image data acquired from each camera 10 as a projection plane T1 on the ground including the boundary D of the runway C, and at least a part of one side of the vehicle A. An image that can be seen from the virtual viewpoint P is generated by mapping on the virtual space as the projection plane T2. The projection plane T1 can be appropriately set according to the design so that the distance range d (see FIG. 2) from the vehicle A to the left is, for example, about 1.5 m to 2 m so as to include the boundary D. .

  The virtual viewpoint P is set to one side (left side) of the vehicle A so that each side surface of the front wheel Ba and the rear wheel Bb of the vehicle A can be seen when the steering angle is zero. The side surface of the wheel is a surface corresponding to the side of the vehicle A. However, the image of the vehicle A including the front wheels Ba and the rear wheels Bb in the display image displayed on the display 30 including the case where the area of the vehicle A is not or small in the angle of view of the camera 10 is not necessarily a real image. Absent.

  The virtual image generation unit 23 generates a virtual image H imitating the vehicle A that can be seen from the virtual viewpoint P, from data that is stored in advance. The virtual image H includes a virtual vehicle image HA that simulates the vehicle body of the vehicle A, and a virtual wheel image HB that simulates the front wheel Ba and the rear wheel Bb. The virtual wheel image HB includes a virtual front wheel image HBa that imitates the front wheel Ba and a virtual rear wheel image HBb that imitates the rear wheel Bb. The virtual image generation unit 23 generates a virtual image H from image data stored in advance. The virtual image generation unit 23 changes the virtual wheel image HB so as to be interlocked with the vehicle speed acquired from the vehicle speed sensor 41. The virtual image generation unit 23 changes the virtual front wheel image HBa so as to be interlocked with the steering angle acquired from the steering angle sensor 42.

  The display image generation unit 24 generates the display image G by inverting the image converted by the image conversion unit 22 left and right. For example, when the angle of view from the virtual viewpoint P is set as in the display range R of FIG. 2, the upper part of the vehicle A may not be included in the display image G due to the angle of view of each camera 10. Therefore, the display image generation unit 24 superimposes the virtual front wheel image HBa, the virtual rear wheel image HBb, and the virtual vehicle body image HA on the display image G as the front wheel Ba, the rear wheel Bb, and the vehicle body of the vehicle A, respectively.

  As shown in FIG. 5, in the display image G, a virtual vehicle body image HA, a virtual front wheel image HBa, and a virtual rear wheel image HBb are shown in areas corresponding to the vehicle body, the front wheel Ba, and the rear wheel Bb of the vehicle A, respectively. Further, since the virtual viewpoint P is set in front of the front wheel Ba, the ratio of the size of the virtual front wheel image HBa to the virtual rear wheel image HBb in the display image G is the ratio of the size of the front wheel Ba to the rear wheel Bb in real space. Bigger than.

  Further, as shown in FIG. 6, the virtual vehicle body image HA may be an image having transparency or an image superimposed as a lower layer of the virtual wheel image HB. Thereby, in the display image G, the whole virtual wheel image HB is reflected, and it becomes easier to visually recognize the behavior. As shown in FIG. 7, since the virtual viewpoint P is set to the left of the vehicle A, the display image G has a side surface of the virtual front wheel image HBa and a virtual rear wheel image HBb when the steering angle is 0. The side is reflected. Note that the side surface of the virtual rear wheel image HBb corresponding to the rear wheel Bb does not necessarily appear in the display image G.

  The output processing unit 25 outputs a signal indicating the display image G generated by the display image generation unit 24 to the display 30 and causes the display 30 to display the display image G. The display 30 displays the display image G according to control by the output processing unit 25.

(Driving support method)
With reference to the flowchart of FIG. 8, an example of operation | movement of the driving assistance device which concerns on embodiment of this invention is demonstrated. A series of tasks shown in the flowchart of FIG. 8 is an example of a driving support method by the driving support device, and each step may be omitted, changed in order, contents, or the like according to various conditions.

  First, in step S101, the condition determination unit 21 determines whether or not the vehicle A has detected a left turn or an operation indicating the start of display processing for the input I / F 50 has been detected. It is determined whether or not display processing after S102 is started. If the condition determination unit 21 determines to start the display process, the process proceeds to step S102. If the condition determination unit 21 does not determine to start the display process, the condition determination unit 21 repeats the process of step S101.

  In step S <b> 102, the image conversion unit 22 acquires an image photographed by each camera 10 from the output signal of each camera 10.

  In step S <b> 103, the image conversion unit 22 sets a projection plane for projecting an image and a virtual viewpoint P in a virtual space relative to the vehicle A. The virtual viewpoint P is set in front of and above the front wheel Ba of the vehicle A and to the left of the vehicle A. The line-of-sight direction Q from the virtual viewpoint P is backward and downward. The angle of view from the virtual viewpoint P is set so as to include the front wheel Ba and the rear wheel Bb.

  In step S104, the image conversion unit 22 maps the image acquired from each camera 10 onto the projection plane set in step S103, and generates an image viewed from the virtual viewpoint P, thereby acquiring the image from each camera 10. A viewpoint conversion process is performed on the image to be processed.

  In step S <b> 105, the display image generation unit 24 generates a display image G by inverting the image converted in step S <b> 104 left and right, and uses the virtual vehicle body image HA generated by the virtual image generation unit 23 as the vehicle body of the vehicle A. Is superimposed on the display image G so as to correspond to.

  In step S106, the display image generation unit 24 superimposes the virtual front wheel image HBa and the virtual rear wheel image HBb generated by the virtual image generation unit 23 on the display image G so as to correspond to the front wheel Ba and the rear wheel Bb, respectively. To do.

  In step S107, the virtual image generation unit 23 monitors the output (steering angle) of the steering angle sensor 42 and determines whether or not there is a change in the output. The virtual image generation unit 23 may set a threshold value for the amount of change in the steering angle, and may determine that the output has changed when it is equal to or greater than the threshold value. When it is determined that there is a change in the output, the virtual image generation unit 23 proceeds to step S108, and when it is determined that there is no change in the output, the virtual image generation unit 23 proceeds to step S109.

  In step S108, the virtual image generation unit 23 changes the virtual front wheel image HBa superimposed on the display image G so as to be interlocked with the steering angle detected by the steering angle sensor 42. Thereby, the virtual front wheel image HBa is linked to the steering direction of the vehicle A in the display image G.

  In step S109, the virtual image generation unit 23 monitors the output (vehicle speed) of the vehicle speed sensor 41 and determines whether or not there is a change in the output. The virtual image generation unit 23 may set a threshold value for the amount of change in the vehicle speed, and may determine that the output has changed when the threshold value is equal to or greater than the threshold value. When it is determined that there is a change in the output, the virtual image generation unit 23 proceeds to step S110, and when it is determined that there is no change in the output, the virtual image generation unit 23 proceeds to step S111.

  In step S110, the virtual image generation unit 23 changes the virtual wheel image HB superimposed on the display image G so as to be interlocked with the vehicle speed detected by the steering angle sensor 42. Thereby, the virtual wheel image HB is interlocked with the speed of the vehicle A in the display image G. The virtual image generation unit 23 may link only the virtual front wheel image HBa displayed larger than the virtual rear wheel image HBb in the display image G with the vehicle speed.

  In step S111, the output processing unit 25 causes the display 30 to display the display image G generated by the processing from step S102 to step S110.

  In step S112, the condition determination unit 21 performs the display process from step S102 to step S111 depending on a predetermined condition such as whether the left turn is completed or an operation indicating the end of the display process for the input I / F 50 is detected. It is determined whether or not to end. When determining that the display process is to be ended, the condition determining unit 21 ends the series of tasks, and when not determining to end the display process, the condition determining unit 21 returns the process to step S102.

  Here, with reference to FIG. 9, an example of the driver's behavior when turning left while viewing an image obtained by overlooking the vehicle A in the vertical direction will be described. First, the driver operates the steering wheel in the left direction to grasp the rudder angle of the front wheel Ba from the image. Next, the driver imagines the position of the turning center E on the rear wheel Bb axle from the rudder angle, and predicts the locus of the rear wheel Bb based on the rudder angle and the turning center E. As a result, the driver predicts a trajectory difference (inner wheel difference) between the front wheels and the rear wheels.

  In this way, it is difficult to accurately predict the inner ring difference when turning while looking at an image that is not familiar to the user. In addition to this, it is conceivable to display the estimated trajectory of the wheels together in an image viewed in the vertical direction, but when steering while traveling, the estimated trajectory becomes the actual trajectory because the speed and steering angle are not constant. It is very difficult to match. In the example shown in FIG. 9, the rudder angle of the front wheel Ba according to the driver's operation input is the information that the driver can recognize most.

  On the other hand, according to the driving assistance apparatus according to the embodiment of the present invention, in the display image G displayed on the display 30, the ratio of the size of the front wheel Ba to the rear wheel Bb is larger than the ratio in real space. Therefore, the driver can recognize even a slight change in the steering angle of the front wheel Ba by looking at the display image G. Further, since the rear wheel Bb positioned at a certain distance from the front wheel Ba is displayed together with the front wheel Ba, the trajectory of the front wheel Ba and the rear wheel Bb can be easily imagined, and therefore steering for avoiding the entrainment due to the inner wheel difference, etc. Timing prediction accuracy is improved. Furthermore, the display image G displays the side surface of the vehicle A so that the angle of the vehicle A with respect to the runway C or the boundary D can be easily grasped.

  In addition, since the front image Ba and the boundary D in the vicinity of the front wheel Ba are greatly reflected in the display image G, the driver can obtain a lot of information on the region in the vicinity of the front wheel Ba including the blind spot, and the situation of the front wheel Ba and the runway C Can be easily grasped. In particular, in an image viewed in the vertical direction, it may be difficult to recognize a three-dimensional obstacle in the vicinity of the front wheel Ba, such as when the boundary D is a curb higher than the runway C, but the display image G is displayed on the front wheel Ba. Since the vicinity appears large, it is easy to recognize a three-dimensional obstacle near the front wheel Ba. In particular, in this embodiment, the virtual viewpoint is set to a position inclined forward from the position at which the overhead image is taken, and the virtual viewpoint is set toward the rear of the vehicle. You will be able to recognize the height.

  Further, according to the driving support apparatus according to the embodiment of the present invention, in the display image G, when the rudder angle is 0, the side surface of the front wheel Ba and the side surface of the rear wheel Bb are reflected. It appears to be closest to D. For this reason, it becomes easy to recognize the change of the space | interval of the side surface of the vehicle A, and the boundary D, and the operativity of driving | operating at the time of turning etc. further improves.

  In addition, according to the driving assistance apparatus according to the embodiment of the present invention, the virtual front wheel image HBa and the virtual rear wheel image HBb are superimposed on the display image G as images of the front wheel Ba and the rear wheel Bb. Generally, since the wheel and the road surface have similar colors, it may be difficult to grasp the contour of the wheel via the screen. The driver can easily grasp the behavior of the wheel from the virtual front wheel image HBa and the virtual rear wheel image HBb. If the virtual front wheel image HBa and the virtual rear wheel image HBb have a color tone that is easy for the driver to visually recognize or can be viewed through the vehicle body of the vehicle A, the behavior of the wheels can be further easily understood.

  In addition, according to the driving support apparatus according to the embodiment of the present invention, the virtual front wheel image HBa is displayed in conjunction with the steering angle of the front wheel Ba, which is a steered wheel. Thereby, the driver can easily grasp the positional relationship of the front wheels Ba on the road C according to the steering, and the operability in the width adjustment to the boundary D is improved.

  In addition, according to the driving support apparatus according to the embodiment of the present invention, the virtual wheel image HB is displayed in conjunction with the speed of the vehicle A. Thereby, the driver can grasp the vehicle speed via the screen, and the driving operation in accordance with the vehicle speed becomes easy.

  Further, according to the driving support apparatus according to the embodiment of the present invention, the display image G is reversed left and right with respect to the image viewed from the virtual viewpoint P, so that the steering direction is actual in the left and right direction of the vehicle A. Match the space. As a result, the driver can perform the driving operation while viewing the image as reflected on the door mirror, so that the driving operability is further improved.

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above-described embodiment, the display image G may be an image obtained by horizontally inverting an image viewed from the virtual viewpoint P and further inverting the image as shown in FIG. That is, in the display image G, the front of the vehicle A corresponds to the upper side of the display 30. Thus, for example, a driver who is accustomed to driving while looking at an image displayed such that the front of the vehicle such as a navigation device is upward can perform a driving operation while looking at the display image G without a sense of incongruity. . Also in this case, since the ratio of the size of the front wheel Ba to the rear wheel Bb is displayed larger than the ratio in the real space, the situation of the front wheel Ba and the road C can be easily grasped. Further, a configuration in which the vertical direction of the display image G can be reversed according to an operation indicating switching of the display method with respect to the input I / F 50 may be employed. Thereby, it becomes possible to display the display image G according to the driver's preference.

  Further, in the above-described embodiment, the condition determination unit 21 may start or end the display process in the driving assistance device according to various other conditions. The driving assistance apparatus according to the embodiment of the present invention is useful in scenes such as narrow roads, S-curves, intersections, etc., in addition to width adjustment. The condition determination unit 21 may start or end the display process based on the position of the vehicle A with respect to a predetermined position in the map information held in advance.

  In the above-described embodiment, the image generation circuit 20 may generate the display image G that reflects both sides of the vehicle A using the two side cameras 12 respectively disposed on the left and right door mirrors. Good. Alternatively, the image generation circuit 20 may switch the display images G on the right side and the left side according to an operation indicating switching of the display range with respect to the input I / F 50.

  Further, the display image G may not necessarily show the virtual vehicle body image HA and the virtual wheel image HB, but may show the front wheel Ba and the rear wheel Bb by actual shooting. Specifically, the image is taken by a camera whose conditions such as the angle of view are determined so that the boundary D, the front wheel Ba and the rear wheel are reflected, and the ratio of the size of the front wheel Ba to the rear wheel Bb is larger than the ratio in the real space. The displayed image may be used as the display image G. Therefore, the display image G is not necessarily an image viewed from the virtual viewpoint P. In this case, the circuit configuration and calculation load for image processing can be reduced, and the manufacturing cost of the driving support device can be reduced.

  Each function described in the above embodiments can be implemented by one or a plurality of processing circuits. The processing circuit includes a programmed processing device such as a processing device including an electrical circuit. The processing circuitry may also include devices such as application specific integrated circuits (ASICs) and circuit components arranged to perform the described functions.

  In addition to the above, the present invention includes various embodiments and the like that are not described here, such as a configuration in which each configuration described in the above embodiment is arbitrarily applied. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

10 Camera 11 Front camera (camera)
12 Side camera (camera)
13 Rear camera (camera)
20 Image generation circuit 30 Display A Vehicle Ba Front wheel Bb Rear wheel C Runway D Boundary G Display image HBa Virtual front wheel image HBb Virtual rear wheel image P Virtual viewpoint

Claims (9)

A camera disposed in the vehicle so as to include a boundary of a road on one side of the vehicle within an angle of view; an image generation circuit that generates a display image from an output signal of the camera; and a display that displays the display image In a driving support method of a driving support device comprising:
The image generation circuit includes generating the display image in which the boundary and the front and rear wheels of the vehicle are reflected, and the ratio of the size of the front wheels to the rear wheels is larger than the ratio in real space. Driving support method.   The driving support method according to claim 1, wherein the display image shows a side surface of the front wheel when the steering angle is zero.   The driving support method according to claim 1, further comprising superimposing a virtual front wheel image simulating the front wheel on the display image as the front wheel by the image generation circuit.   The driving support method according to claim 3, wherein the virtual front wheel image is linked to a steering angle of the front wheel.   The driving support method according to claim 3 or 4, wherein the virtual front wheel image is linked to a speed of the vehicle.   6. The driving support method according to claim 1, wherein a front side of the vehicle in the display image corresponds to an upper side of the display.   The display image is generated by converting the image acquired from the output signal of the camera by the image generation circuit into an image viewed rearward and downward from a virtual viewpoint set frontward and upward of the front wheel. The driving support method according to any one of claims 1 to 6, wherein:   The driving support method according to claim 7, wherein the display image is horizontally reversed with respect to the image viewed from the virtual viewpoint. A camera disposed on the vehicle so as to include a boundary of a runway on one side of the vehicle within an angle of view;
An image generation circuit for generating a display image from an output signal of the camera;
A display for displaying the display image,
The image generation circuit generates the display image in which the boundary and front wheels and rear wheels of the vehicle are reflected, and a ratio of the size of the front wheels to the rear wheels is larger than the ratio in real space. Driving assistance device.

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