JP2010047105A - Driving assistance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving assistance system capable of improving visibility when reversing a vehicle for parking by displaying an image obtained by photographing the rear side of the vehicle including the rear wheels with a predicted reversing locus superimposed. <P>SOLUTION: The driving assistance system includes a photographing means (10) photographing the periphery of the vehicle having a photographing field including at least the rear wheels (61) of the vehicle; a display means (20) displaying an image photographed by the photographing means; a traveling state detection means (30) detecting the traveling state (31-36) of the vehicle; and a control means (40) switching images to be displayed according to the traveling state. When the vehicle is reversed (R), the control means allows the display means to display an original image (15) photographed so as to include the rear wheels and the rear side of the vehicle on the rear wheel side in one image, and to superimpose the predicted reversing locus (46, 47) of the rear wheels in the case where the vehicle is reversed at a predetermined steering angle (35) on the original image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving support apparatus, and more particularly, to an apparatus that displays a predicted backward trajectory superimposed on an image of a rear side of a vehicle including a rear wheel.

  In order for the vehicle to travel safely, the occupant visually checks not only the front but also the rear and the side with a door mirror or a rear-view mirror provided on the vehicle.

  In particular, when the vehicle is parked by reversing the vehicle, there are many areas in which the occupant cannot directly visually recognize, so it is necessary to frequently check the surroundings of the vehicle with a plurality of mirrors.

  Therefore, in order to enlarge the range that can be seen by the occupant as much as possible, the “reverse interlocking mirror” changes the field of view by moving the door mirror downward mechanically, for example, when the transmission is switched to reverse, according to changes in driving conditions. The technique of this is disclosed (for example, patent document 1).

  However, the field of view behind or behind the vehicle is limited only by the door mirror or the rearview mirror. Furthermore, in order for the occupant to see the rearview mirrors arranged in front and above the center of the vehicle interior and the door mirrors arranged on the left and right front doors, the direction of the line of sight must be greatly changed, and careful actions are taken. It was necessary.

  Therefore, a technology has been developed to widen the field of view of the passenger and to capture the surroundings of the vehicle with a camera or other imaging means so that the passenger does not have to move his line of sight and display the captured image on the display in the passenger compartment. Has been.

  Among these technologies, there is disclosed a so-called “back monitor” technology that assists in the visual sense when the vehicle is parked while being retracted (for example, Patent Document 2).

The back monitor is a device that captures the rear of the vehicle with a camera or other imaging means and displays the captured image on a display in the passenger compartment. A wide-angle lens is used to widen the horizontal viewing angle. Technology has also been developed.
JP 2005-29150 A Japanese Patent No. 4061219

  In the back monitor using a normal camera, it is difficult to photograph the left and right corners of the rear bumper which is easy to hit first when parked backward due to the limitation of the camera mounting position. Therefore, ingenuity has been devised to expand the field of view of the image by using, for example, an ultra-wide angle lens of 180 degrees or more for a part of a vehicle that is difficult to image with a camera equipped with a normal lens. However, images taken using an ultra-wide-angle lens cannot avoid image distortion, etc., and it is very difficult to grasp the positional relationship and sense of distance between parts of the vehicle that need to be viewed and surrounding obstacles. there were.

  Also, a back monitor that displays a predicted rearward trajectory of the rear wheel when the vehicle is moving backward has been developed. However, at the camera mounting position described above, a real image of the rear wheel of the vehicle cannot be taken, and the actual rear wheel and the predicted backward trajectory cannot be projected simultaneously.

  For example, when retreating and parking in a three-dimensional pallet parking lot such as a condominium or a department store, it is necessary to retreat while simultaneously closing off the actual rear wheels and the left and right corners of the rear bumper and surrounding obstacles. However, there is a possibility that the visual field range is insufficient only with the display area of the back monitor.

  Here, since the backward prediction locus is information of a virtual image superimposed on the screen, it is necessary to visually recognize the actual position of the rear wheel. Therefore, it was necessary to visually recognize the actual rear wheel using a door mirror together with the back monitor. However, it is difficult to see the rear wheels in most vehicle types only with the viewing range of the door mirror at the normal position. To solve this problem, a technique as described in Patent Document 1 has been developed.

  However, since the occupant still needs to visually recognize the back monitor, change the line of sight, and visually recognize the door mirror, it has not been solved.

  The present invention provides a driving assistance device that superimposes and displays a backward predicted locus on an image of a rear side of a vehicle including a rear wheel, which improves visibility especially when the vehicle is parked backward. For the purpose.

  In order to solve the above-described problem, an embodiment of the present invention is a driving support device that displays an image of the periphery of a vehicle so that the driver can see the image, and includes at least a rear view of the vehicle. An image capturing unit that captures the periphery of the vehicle, a display unit that displays an image captured by the image capturing unit, a travel state detection unit that detects a travel state of the vehicle, and a display according to the travel state Control means for switching images, and the control means was photographed such that when the vehicle moves backward, the rear wheel and the rear side of the vehicle on the rear wheel side are included in one image. An image is displayed on the display means, and the predicted rearward trajectory of the rear wheel when the vehicle moves backward at a predetermined steering angle is superimposed on the captured image.

  According to the above-described configuration, for example, when a vehicle is parked backward in a parking lot, an image in which a rear wheel real image and an expected backward trajectory thereof are superimposed can be displayed. You can easily grasp the positional relationship and sense of distance. Further, the trouble of visually recognizing the actual rear wheel by a mirror or the like can be minimized, and the troublesomeness is reduced.

  According to the present invention, there is provided a driving support device that improves visibility when a vehicle is moved backward, and displays an image of the rear side of the vehicle including a rear wheel superimposed on a predicted backward trajectory. Can be provided.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a driving support device according to the present embodiment, FIG. 2 is an explanatory diagram of the operation of the driving support device when the vehicle moves backward, and (a) is a plan view seen from above. (B) is explanatory drawing of one Example of a display screen, (c) is description which shows an example of reverse prediction locus | trajectory calculation.

  In the present embodiment, as shown in FIG. 1, a camera (photographing means) 10 (11, 12, 13) for photographing the rear and rear sides of the vehicle, and a display (display) for displaying an image 15 photographed by the camera 10 are displayed. Means) 20, a running condition detecting device (running condition detecting means) 30 for detecting the running condition of the vehicle such as the yaw angle and the yaw rate, and an ECU for displaying on the display 20 with the predicted backward loci 46 and 47 superimposed on the image 15. (Control means) 40 and a switching SW (switching means) 50 for manually switching displayed images.

  The photographing device 10 is, for example, a camera 10 disposed on the lower and rear sides of a door mirror (not shown). In this embodiment, as shown in FIG. 2A, on the left side in the vehicle head direction. There are three cameras 10, a camera 12 on the rear side and a camera 13 on the right side.

  As the camera 10, a normal visible light camera can be used. For example, a CMOS camera and a CCD camera can be applied.

  An image 15 captured by the camera 10 in the rear or rear side of the vehicle is once sent to the ECU 40 and displayed on the display 20.

  The display 20 is not particularly limited as long as it can display an image, and a display of a car navigation system (hereinafter referred to as “car navigation”), a monitor display of equipment installed in a vehicle such as an audio or an air conditioner, and the like can be applied.

  The traveling state detection device 30 detects a traveling state. The running state includes a yaw angle 31, a yaw rate 32, a shift position (transmission state) 33, lighting or extinguishing of headlights, device operation 34 such as wiper operation and defroster operation, steering angle 35, travel locus 36, and the like. And is detected by a sensor, GPS, or the like. Note that these are merely examples, and the traveling states are appropriately combined according to the examples described later. Therefore, it is not necessary to provide all of the essential configurations, and other traveling states can be acquired.

  The ECU 40 in the present embodiment includes at least a memory (storage means) 41, a predicted reverse trajectory calculation device 42, a traveling state determination unit 43, a parking end determination unit (parking end determination unit) 44, and a parking space estimation device ( Parking space estimating means) 45. These are merely examples, and combinations are appropriately performed in accordance with examples to be described later. Therefore, it is not necessary to provide all as essential components. For example, in a vehicle equipped with a car navigation system, if the car navigation system can have a part of the functions of each device, a device that supplements the deficient function may be added.

  The memory 41 stores the detection result of the traveling state detection device 30 at a constant period. The traveling state detection device 30 always detects the traveling state of the vehicle, and the memory 41 stores the traveling state for a predetermined time interval or a predetermined distance interval (constant period) when the vehicle travels. After that, when a new running state is continuously detected and a certain period has passed again, the memory 41 deletes the running state detected in the previous cycle and stores the running state detected in the current cycle. This means that when the vehicle is parked backward, for example, the vehicle 60 is generally stopped at the position shown in the upper side of FIG. 2A, and the position of the vehicle before reaching the position and the position. This is because the travel state information such as (yaw angle 31, yaw rate 32) and rudder angle 35 improves the accuracy of the predicted backward trajectory.

  As shown in FIG. 2A, the predicted backward trajectory calculation device 42 calculates a trajectory that is expected to follow the rear wheels when the vehicle is retracted and parked in the parking space P on the side surface of the vehicle 60. .

  When parking, the passenger operates a steering (not shown) to steer the vehicle. The occupant moves the vehicle 60 backward in the direction of the arrow R while finely adjusting the steering operation amount while visually checking the periphery of the vehicle. Therefore, in the present embodiment, as shown in FIG. 2, the steering angle interlocking predicted locus 46 that is interlocked with the current steering angle, which is the steering operation amount, and the full steering that represents a margin of an amount that can be further steered. Two predicted backward trajectories of the predicted trajectory 47 of time are calculated. The calculated predicted backward trajectories 46 and 47 are superimposed on the image 15 and displayed on the display 20. FIG. 2B is a display example of the superimposed image.

  The traveling state determination unit 43 determines which of the cameras 10 of the left rear side camera 11, the rear camera 12, and the right rear side camera 13 is to be displayed. In the present embodiment, as will be described later, the integrated value of the measured value of the yaw angle (azimuth angle of the traveling vehicle) 31 and the yaw rate (speed at which the rotation angle changes in the turning direction of the vehicle) 32 is adopted in the determination. .

  As described above, since the memory 41 periodically stores the data on the traveling state, the measured angle is determined based on the traveling locus until the vehicle reaches the position of FIG. It can be. In addition, the yaw rate 32 is also integrated before starting to reverse for parking. With this configuration, it is possible to improve the accuracy in determining which of the cameras 10 (11, 12, 13) is suitable for selecting an image taken.

  The parking end determination unit 44 detects the traveling state or refers to the past traveling state from the memory 41. Here, at least the ignition switch is turned off, the shift position 33 is parked, the vehicle stops for a predetermined time, the reverse state of the shift position 33 is not detected and recorded between the present time and the predetermined time, and the vehicle travels to the current location. If any one of the following states is detected: no reverse state detection record of the shift position 33 and exceeding a predetermined speed in the forward state during a predetermined distance from the current position on 36. Determines that the vehicle has been parked.

  The parking space estimation device 45 estimates a parking space by recognizing one frame line that is substantially parallel to the traveling direction when the vehicle is parked in the parking space where a certain area is divided. As will be described in detail later, this area is imaged when the other vehicle is parked in the parking space, as well as when the area is delimited by the actual frame drawn on the road. A parking space can also be estimated by estimating a virtual frame line based on a plurality of points on the side surface of another vehicle and recognizing the virtual frame line as a frame line from the image.

  The switch SW50 is for manually switching images when the occupant wants to see images other than the images displayed on the display 20, map information, or the like.

  Although there is a part which overlaps somewhat with the above-mentioned content, with reference to FIG. 2, the effect | action of the driving assistance device concerning this embodiment is demonstrated. In the following description, the direction of the center line CL connecting the front and rear ends of the vehicle 60 in (a) is the X direction, and the direction orthogonal to X is the Y direction.

  FIG. 2 (a) shows that the vehicle 60 moves backward from the corner RC side of the parking space P to the parking space P partitioned by the frame lines 71, 72L, 72R drawn on the road. It is the top view which looked down at the condition which it drive | works to a minus direction and has stopped in the position beyond the corner LC. In the drawing, another vehicle 65 is already parked on the left side (minus X direction) of the parking space P.

  Since the center line CL extending in the substantially X direction is substantially in the Y direction when parked in the parking space P, the occupant needs to retreat the vehicle 60 while drawing a curve in the arrow R direction. Although not shown in the drawing, another vehicle may be parked in the parking space right next to the parking space P, or the parking space P may be surrounded by a wall or the like. Needs to be retreated to the parking space P from between the corner LC and the corner RC on the frame 71.

  The vehicle 60 is provided with three cameras 10, a camera 11 below the left door mirror, a camera 12 on the rear side, and a camera 13 below the right door mirror with respect to the negative X direction (leading direction). In the figure, the visual field range VA of the camera 11 is shown as an example. As can be seen by referring also to FIG. 2B, the field of view range VA includes the side of the vehicle 60 including the left rear wheel 61 as well as the situation of the left rear side of the vehicle 60.

  The predicted backward trajectory calculation device 42 calculates the predicted backward trajectory when the vehicle 60 is parked in the parking space P. As described above, in the present embodiment, the two backward movements of the predicted steering angle-linked locus 46 linked to the current steering angle, which is the steering operation amount, and the predicted locus 47 at the time of full steering that represents a margin for the steering angle adjustment. The expected trajectory is calculated. The calculated steering angle interlocking predicted backward trajectory 46 is represented by a solid line in FIG. 2A, and the predicted backward traveling trajectory 47 during full steering is represented by a broken line. The predicted backward trajectories 46 and 47 are superimposed on the image 15 and displayed on the display 20. FIG. 2B is a display example of the superimposed image.

  As shown in FIG. 2B, the image 15 displayed on the display 20 includes a rear wheel 61, and the predicted backward trajectories 46 and 47 are superimposed as curves extending from the rear wheel 61. Is displayed.

  With reference to FIG. 2 (c), an embodiment of the predicted backward trajectory will be described. In FIG. 2C, the description will be made using the same X and Y coordinate axes as in FIG. 2A. For example, the lower right point P00 in FIG. 2C is assumed to be located at the coordinates (X00, Y00). Here, the point P00 indicates the position of the rear wheel 61 of the vehicle 60 that is stopped as shown in (b).

  The broken line segment L47 is a segment obtained by combining a plurality of straight lines drawn from the point P00 to the point P347 via the points P147 and P247. The predicted trajectory 47 at the time of full steering is obtained by smoothing the broken line segment L47 and displaying the curve.

  Next, the broken line segment L48 is a line segment obtained by combining a plurality of straight lines drawn from the point P00 to the point P348 via the points P148 and P248. The broken line segment L48 is smoothed and displayed in a curved line, so that a predicted backward trajectory at an arbitrary rudder angle between full steering and straight traveling is acquired.

  The coordinates of the respective points constituting the broken line segments L47 and L48 are acquired in advance and stored in the memory 41 of the ECU 40 or the storage device of the predicted backward trajectory calculation device 42 itself. The number of coordinates of the broken line segment to be stored is set according to the calculation accuracy of the steering angle-linked backward predicted locus 46 described later, the capacity of the storage device, or the like.

  The solid line segment L46 is a line segment obtained by combining a plurality of straight lines drawn from the point P00 to the point P346 via the points P146 and P246. It becomes. The coordinates of the points P146, 246 and 346 of the solid line segment L46 are calculated by interpolation from the points constituting the broken line segments L47 and L48.

  Next, the coordinate interpolation calculation method will be described using the point P346 as an example. When the steering angle when the vehicle 60 is about to reverse is θ346, θ346 is an angle between the steering angle θ347 of the broken line segment L47 and the steering angle θ348 of the broken line segment L48. Here, in order to simplify the description, the steering angle θ346 is set to an intermediate between the steering angle θ347 and the steering angle θ348, that is, an angle of (θ347 + θ348) / 2.

  The coordinates of the point 347 and the point 348 are acquired in advance, and these coordinates are the X coordinate, X47, and X48 with respect to a common arbitrary Y coordinate Y03.

X46 of the coordinates (X46, Y03) of the point 346 is calculated by interpolation as follows.
X46 = (X47 + X48) / 2

  Similarly, the coordinates of the points P146 and 246 are interpolated to obtain a solid line segment L46, which is smoothed and displayed in a curved line to become a steering angle-linked backward trajectory 46.

  In addition, it is needless to say that the above-described method of calculating the predicted backward trajectory is an example and is not limited to this method. That is, even when the X coordinate is not acquired when the Y coordinate is fixed, interpolation can be performed by applying a normal geometric calculation, and the steering angle to be calculated is intermediate between the steering angles acquired in advance. Even if this is not the case, interpolation calculation can be performed by proportionally proportionally dividing.

  With this image configuration, it is possible to display an image in which the real image of the rear wheel and the predicted backward trajectory are superimposed, so that the positional relationship between the obstacles around the vehicle and the vehicle can be easily grasped. Can do. Moreover, the range where the position of the vehicle 60 can be adjusted by operating the steering wheel can be easily grasped by displaying the predicted backward trajectories 46 and 47.

[Example 1]
Next, referring to the figure, an embodiment for switching between images taken by the rear side cameras 11 and 13 (rear side monitor) and images taken by the rear camera 12 (back monitor) from the information of the yaw angle 31. Will be described.

  FIG. 3 is a flowchart for switching the rear side monitor and the back monitor based on the information on the yaw angle 31 of the vehicle, FIG. 4 is a diagram showing the correspondence between the yaw angle and the rear side monitor or the back monitor, and FIG. It is an explanatory top view showing the posture or behavior of the vehicle concerning monitor switching.

  As shown in FIG. 3, the traveling state detection device 30 detects the yaw rate 32, and the detection result is temporarily stored, for example, in a ring buffer provided in the memory 41 (step S01). Note that the detection results stored as described above are periodically rewritten. This operation is always executed, for example, at positions P1 and P2 of the vehicle 60 in FIG. Here, the alternate long and short dash line represents the travel locus FT of the left front wheel of the vehicle 60. The traveling locus of the vehicle 60 including the traveling locus FT is periodically stored as described above. In the following drawings, the travel locus FT is also used to represent the change in travel of the vehicle 60.

  When the vehicle 60 reaches the position P2 in FIG. 5 and stops temporarily, and the shift position 33 is in the reverse state (R) (step S02: YES), the running state determination unit 43 adds the yaw rate 32 or the yaw rate. Measurement of the corner 31 is started (step S03). This integration and measurement are continuously executed from the state before the predetermined time or the predetermined distance before the shift position 33 is switched to the reverse state to the present time and thereafter with reference to the detection result stored in the ring buffer. . In the present embodiment, by applying such a configuration, it is possible to refer to the traveling state detection result before the transition to the operation of reversing and parking, and the accuracy of the integration result of the yaw rate 32 or the measurement result of the yaw angle 31 can be improved. Can be improved.

  As an example of the integration of the yaw rate 32 or the start of the measurement of the yaw angle 31, it can be set 5 seconds before the shift position 33 is switched to the reverse state. Further, it may be a change point from a state in which a state in which the constant steering angle or yaw rate is 0 immediately before the shift position 33 is switched to the reverse state continues for a certain distance or for a certain period of time.

  When the vehicle 60 has already retreated and stopped from the position P3 in FIG. 5, since the parking has been completed, the monitor switching is also completed (step S04: YES). Whether or not parking has ended at this time is determined whether the parking end determination unit 44 detects the traveling state or refers to the past traveling state from the memory 41, detects at least the ignition switch OFF, Detects parking state (P), detects a stop exceeding a predetermined time, detects that there is no record of detection of reverse state (R) of shift position 33 between the present time and a predetermined time before, travel locus to the current location of the vehicle One of the following: detecting that there is no record of detection of the reverse state (R) of the shift position 33 between the current position and a predetermined distance on 36, and detecting that the predetermined speed has been exceeded in the forward state, or When two or more traveling states are detected, it is determined that the vehicle has been parked (step S04).

  If parking has not ended (step S04: NO), the rear side monitor or the back monitor is selected according to the detected yaw angle 31, and the image is switched.

  In the following description, FIG. 4 is also referred to. The yaw angle of the posture AT4 of the vehicle 60 in FIG. 4 corresponds to the case where the vehicle 60 is traveling straight from the position P0 to the position P1 in FIG. FIG. 4 shows the respective postures corresponding to the case where the vehicle 60 in the posture AT4 parks backward in a parking space (not shown) in the arrow RD direction or a parking space (not shown) in the arrow LD direction. Show.

  When 0 ≦ yaw angle <70 or yaw angle ≦ −110 (step S05: YES), the posture of the vehicle 60 is the posture AT1 or the posture AT5 as shown in FIG. When the vehicle 60 is to be parked backward, it is necessary to consider a parting with an obstacle such as an adjacent vehicle. Therefore, in the case of postures AT1 and AT5, an image (right rear) taken by the right rear side camera 13 is used. (Side monitor) is displayed on the display 20 (step S06).

  When −70 <yaw angle <0 or 110 ≦ yaw angle (step S07: YES), the posture of the vehicle 60 is the posture AT3 or the posture AT7 as shown in FIG. When parking the vehicle 60 backward, it is necessary to consider a close-off with an obstacle such as an adjacent vehicle. Therefore, in the case of postures AT3 and AT7, an image (left rear) taken by the left rear side camera 11 is taken. (Side monitor) is displayed on the display 20 (step S08).

  When both steps S05 and S07 are NO, the posture of the vehicle 60 is the posture AT2 or the posture AT6 as shown in FIG. In the case of postures AT2 and AT6, the vehicle 60 is not largely steered and moved backward, so an image (back monitor) taken by the rear camera 12 is displayed on the display 20 (step S09).

  The vehicle 60 in FIG. 5 corresponds to the transition from the posture AT3 to the posture AT2 in FIG. 4, and the left rear side monitor is displayed at the position P2, and the position P3 from when the yaw angle exceeds −70 degrees. On the other hand, the display is switched to the back monitor.

  In some cases, the vehicle 60 may be moved forward by turning the vehicle 60 backward when the vehicle is parked. In this case, the left rear side monitor, the right rear side monitor, or the back monitor may be continuously displayed. If the parking end condition is not met, the integrated yaw rate value or yaw angle measurement value may be taken over. By setting it as this structure, a passenger | crew can park with a margin.

  In addition, since it takes time to confirm safety in rainy days and dark conditions at night, it may be configured to lengthen the determination time of the parking end condition according to the operating conditions of the headlight, wiper, defroster, etc. .

  Next, an example of calculating the yaw angle will be described with reference to the drawings. FIG. 6 is an explanatory diagram for calculating the yaw angle using the rudder angle and the moving distance, and FIG. 7 is an explanatory diagram for calculating the yaw angle when the rudder angle changes during forward or backward movement of the vehicle.

[Yaw angle calculation example 1]
As shown in FIG. 6A, the vehicle 60 that is to be parked in the parking space P travels from the position P0 to the position P1 in parallel with the frame line 71, and the occupant determines the parking space P. When the parking space P is determined and the vehicle 60 is moved backward to enter the parking space P, the vehicle 60 is moved from the position P1 to the position P2 with a large steering angle to the right and in a posture that makes it as easy as possible to enter the parking space P. Move forward. The posture at this time varies depending on the surrounding obstacles, the width of the passage in the parking lot, and the like.

  The vehicle 60 that has reached the position P2 is shifted to the parking space P via the position P3 after the shift position 33 is changed to the reverse state, moves backward so as to enter between the frame lines 72L and 72R on both sides of the parking space P. Park.

  In this embodiment, it is assumed that the steering angle does not change while the vehicle 60 is moving forward or backward.

  FIG. 6B schematically shows the movement locus and the positional relationship of the posture of the vehicle 60 at the positions P1, P2, and P3 in FIG. Here, since the traveling of the target vehicle 60 is a movement locus in a low speed region called parking, in order to make the explanation easy to understand, in FIG. In the two-wheeled vehicle model, a line segment drawn from the top to the rear end inside the vehicle 60 at positions P1, P2, and P3 in FIG. And the rear wheel 61 are shown. Each reference number is the same in (b).

  In this embodiment, as described above, the measurement of the yaw angle 31 can be started from a predetermined distance before the shift position 33 is changed to the reverse state. In FIG. 6 (b), measurement of the yaw angle is started from the position P1, and the yaw angle when the vehicle 60 assumes the posture of the position P3, that is, the total yaw angle that has passed from forward to backward is calculated.

Each symbol in FIG. 6B is as follows.
w: Wheel base Fixed value σ: Rudder angle Measured value (f: forward, r: reverse)
L: Vehicle travel distance Measured value (f: forward, r: reverse)
R: Calculated vehicle turning radius (f: forward, r: reverse)
θ: Calculated vehicle yaw angle (f: forward, r: reverse)

The yaw angle θf when the vehicle 60 moves forward from the position P1 to the position P2 is as follows.
Rf = w / tan σf
θf = Lf / Rf = Lf / (w / tan σf)

The yaw angle θr when the vehicle 60 moves backward from the position P2 to the position P3 is as follows.
Rr = w / tan σr
θr = Lr / Rr = Lr / (w / tan σr)

Accordingly, as described below, the total yaw angle θ is calculated by adding the backward yaw angle θr to the forward yaw angle θf.
θ = θf + θr = Lf / (w / tan σf) + Lr / (w / tan σr)

  Based on the correspondence between the calculated yaw angle θ and the rear side monitor or the back monitor shown in FIG. 4, an image photographed by one of the cameras 10 (11, 12, 13) is selected.

[Yaw angle calculation example 2]
FIG. 7 shows a calculation example of the yaw angle when the steering angle is changed at the position Pm while the vehicle 60 moves forward from the position P1 to the position P2.

  In the following description, a description will be given focusing on parts different from the yaw angle calculation example 1. The symbols used are the same as those in the yaw angle calculation example 1, but the state from the position P1 to the position Pm is f1, and the state from the position Pm to the position P2 is f2.

The yaw angle θf1 when the vehicle 60 moves forward from the position P1 to the position Pm is as follows.
Rf1 = w / tan σf1
θf1 = Lf1 / Rf1 = Lf1 / (w / tan σf1)

The yaw angle θf2 when the vehicle 60 moves forward from the position Pm to the position P2 is as follows.
Rf2 = w / tan σf2
θf2 = Lf2 / Rf2 = Lf2 / (w / tan σf2)

Therefore, the total yaw angle θf is calculated by adding the yaw angle θf2 to the forward yaw angle θf1 as described below.
θf = θf1 + θf2 = Lf1 / (w / tanσf1) + Lf2 / (w / tanσf2)

  The calculated yaw angle θf can be used as θf in the yaw angle calculation example 1 described above.

[Example 2]
Next, Example 2 of the first embodiment of the present invention will be described with reference to the drawings. Note that portions that are the same as those in the first embodiment are omitted, and the differences are mainly described. FIG. 8 is an explanatory plan view showing an example of switching between the rear side monitor and the back monitor based on information on the steering angle 35 of the vehicle. In the following description, the rudder angle 35 is set to 0 degrees in a straight line, the left is a plus side, and the right is a minus side.

  After the shift position 33 is changed to the reverse state at the position P1, measurement of the steering angle 35 is started. The vehicle 60 is going to park in the parking space P on the left side in the traveling direction. Therefore, the rudder angle 35 is greatly operated to the left. In order to accommodate the vehicle 60 between the frame line 72L and the frame line 72R in consideration of the inner ring difference and the like, the occupant needs to visually recognize the left rear side in particular. The driving support device selects an image of the camera 11 that captures the left rear side (left rear monitor) and displays it on the display 20.

  Thereafter, when the vehicle advances backward and the vehicle 60 reaches the position P2, the possibility that the vehicle 60 deviates from between the frame lines 72L and 72R becomes low. Therefore, the occupant needs to pay attention to the presence or absence of a rear obstacle when the vehicle 60 is further moved backward. Therefore, the driving support apparatus switches the image (back monitor) to the video of the camera 12 that captures the rear.

  When the parking space P is on the right side in the traveling direction of the vehicle 60 and the vehicle is retracted and parked in the parking space P, the right rear monitor shifts to the back monitor.

  For example, when the steering angle 35 is 20 degrees or more, the left rear monitor, when it is less than 20 degrees and minus 20 degrees or more, it is a back monitor, and when it is less than minus 20 degrees, it is the right rear side monitor. Therefore, it is possible to contribute to the visual recognition at the time of reverse parking.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to the drawings. Note that portions that are the same as those in the first embodiment are omitted, and the differences will be mainly described. FIG. 9 is an explanatory diagram of the operation of the driving support device when the vehicle moves backward, (a) is a plan view seen from above, and (b) is an explanatory diagram of an embodiment of the display screen.

  The present embodiment relates to estimation of a parking space area, and the basic configuration is the same as that of the first embodiment.

  When there is a frame line in the parking space, the driving support device according to the present embodiment can recognize the frame line from an image of the rear side or the rear side image using a known technique or the like.

  In addition, even in a parking space where no frame line is drawn, when parking next to another vehicle that has already been parked or between other vehicles, any two of the side surfaces of the other vehicles that are in the field of view A point, for example, a hub connecting the front and rear wheels, a line connecting the upper and lower ends, can be estimated as a frame line, and a projection onto a road near the side surface of another vehicle can be estimated as a frame line. The present embodiment recognizes the frame line in this way, or recognizes the estimated virtual frame line.

  FIG. 9 shows a situation in which the vehicle 60 moves backward in the parking space P and parks. In FIG. 9A, the frame lines 72L and 72R are drawn, but these frame lines 72L and 72R may be frame lines drawn in advance in the parking space P or are already parked. It may be a virtual frame line estimated from an image of the side surface of another vehicle 65 or the like.

  Assuming that the line connecting the front and rear ends of the vehicle 60 is the vehicle attitude AT, the angle α between the attitude AT and the left frame line 72L represents a deviation in parallelism between the vehicle 60 and the parking space P. In the present embodiment, the image displayed on the display 20 is switched according to the angle α. In the following description, with respect to the angle α, the frame line 72L is 0 degree, and when the head of the vehicle 60 faces the left side of the frame line, the plus side, and when the head of the vehicle 60 faces the right side, the minus side.

  The angle α is calculated by converting the viewpoint angle with respect to the image captured by the rear camera 12. Such a method is a known technique, but will be briefly described. First, when the camera 12 is mounted, calibration is performed so that a direction in which the line of the posture AT coincides with the vehicle traveling direction can be indicated. By this calibration, an attitude AT as shown in FIG. 9B is obtained. Next, the posture AT and the frame lines 72L and 72R are converted into an overhead coordinate system as shown in FIG. In this overhead view coordinate system, an angle formed between the posture AT and the frame line 72L is calculated and set as an angle α.

  After the shift position 33 is changed to the reverse state at the position P1, the measurement of the posture AT is started. The vehicle 60 is going to park in the parking space P on the left side in the traveling direction. Therefore, the angle α is a large angle in the plus direction. In order to accommodate the vehicle 60 between the frame line 72L and the frame line 72R in consideration of the inner ring difference and the like, the occupant needs to visually recognize the left rear side in particular. The driving support device selects an image of the camera 11 that captures the left rear side (left rear monitor) and displays it on the display 20.

  Thereafter, when the vehicle advances backward and the vehicle 60 reaches the position P2, the possibility that the vehicle 60 deviates from between the frame lines 72L and 72R becomes low. Therefore, the occupant needs to pay attention to the presence or absence of a rear obstacle when the vehicle 60 is further moved backward. Therefore, the driving support apparatus switches the image (back monitor) to the video of the camera 12 that captures the rear.

  When the parking space P is on the right side in the traveling direction of the vehicle 60 and the vehicle is retracted and parked in the parking space P, the right rear monitor shifts to the back monitor.

  For example, when the angle α is 20 degrees or more, the left rear monitor, when it is less than 20 degrees and minus 20 degrees or more, the back monitor, and when it is less than minus 20 degrees, the right rear side monitor is used. , Can contribute to visual recognition in the case of reverse parking.

  FIG. 9B is an example of the displayed back monitor. As shown in the figure, the recognized frame lines 72L and 72R are displayed, and the predicted backward trajectory 46 is superimposed and displayed. Thus, this embodiment can provide visual assistance for parking regardless of the presence or absence of a parking lot borderline. Note that the posture AT line is not normally displayed.

  The preferred embodiments of the present invention have been described above. The present invention is not limited to the one described in the drawings, and design changes can be made without departing from the spirit of the present invention.

It is a block diagram which shows the structure of the driving assistance device concerning 1st Embodiment. It is operation | movement explanatory drawing of a driving assistance device when a vehicle reverse | retreats, (a) is a top view looked down from the sky, (b) is explanatory drawing of one Example of a display screen, (c) is a reverse prediction locus | trajectory. It is explanatory drawing which shows an example of calculation. It is a flowchart which switches a rear side monitor and a back monitor from the information of the yaw angle 31 of a vehicle. It is a figure showing a response | compatibility with a yaw angle and a rear side monitor or a back monitor. It is an explanatory top view showing the posture or behavior of the vehicle concerning monitor switching. It is explanatory drawing which calculates a yaw angle using a steering angle and a movement distance. It is explanatory drawing which calculates a yaw angle when a steering angle changes in the middle of a vehicle forward or backward. It is an explanatory top view showing an example which switches a back side monitor and a back monitor from information on a steering angle of vehicles. It is operation | movement explanatory drawing of the driving assistance apparatus when the vehicle concerning 3rd Embodiment reverse | retreats, (a) is a top view looked down from the sky, (b) is explanatory drawing of one Example of a display screen.

Explanation of symbols

10, 11, 12, 13 Camera 15 Image 20 Display 30 Traveling state detection device 31 Yaw angle 32 Yaw rate 33 Shift position 34 Device operation 35 Steering angle 36 Traveling track 40 ECU
41 Memory 42 Estimated Backward Trajectory Calculation Device 43 Traveling State Determination Unit 44 Parking End Determination Unit 45 Parking Space Estimation Device 46, 47 Expected Backward Trajectory 50 Switch SW
60 Vehicle 61 Rear wheel 62 Front wheel 65 Other vehicle 71, 72L, 72R Frame P Parking space θ Yaw angle (calculation)

Claims (18)

A driving support device that displays an image of the periphery of a vehicle so that the driver can see the image,
Photographing means for photographing the periphery of the vehicle with a photographing field including at least a rear wheel of the vehicle;
Display means for displaying an image taken by the photographing means;
Traveling state detecting means for detecting the traveling state of the vehicle;
Control means for switching an image to be displayed according to the running state,
The control means causes the display means to display an image taken so that the rear wheel and the rear side of the vehicle on the rear wheel side are included in one image when the vehicle moves backward,
A driving assistance device that superimposes the predicted rearward trajectory of the rear wheel on the captured image when the vehicle moves backward at a predetermined steering angle. The photographing means includes a photographing visual field behind the vehicle,
The running state includes at least a yaw angle,
The driving support apparatus according to claim 1, wherein the control unit causes the display unit to display an image of either a rear side or a rear side of the vehicle according to the yaw angle. The photographing means includes a photographing visual field behind the vehicle,
The running state includes at least a yaw rate,
The driving support apparatus according to claim 1, wherein the control unit causes the display unit to display an image of either a rear side or a rear side of the vehicle according to the yaw rate. The apparatus further comprises storage means for storing the detected traveling state while the vehicle is traveling.
When the vehicle moves backward, the control means starts accumulating the yaw rate or starts measuring the yaw angle from the yaw rate or yaw angle stored in the storage means a predetermined distance before the reverse starts. The driving support device according to claim 2 or 3. The apparatus further comprises storage means for storing the detected traveling state while the vehicle is traveling.
When the vehicle moves backward, the control means starts yaw rate integration or starts yaw angle measurement from the yaw rate or yaw angle stored in the storage means a predetermined time before the reverse starts. The driving support device according to claim 2 or 3.   The driving support device according to any one of claims 1 to 5, wherein the control means determines that the vehicle moves backward when a reverse state of the transmission is detected. The running state includes device operation of the vehicle,
The driving support device according to any one of claims 1 to 5, wherein when the device operation is detected, the control unit causes the display unit to display any rear side or rear image of the vehicle.   The driving support apparatus according to claim 7, wherein the device operation includes at least turning on / off of a headlight, operation of a wiper, and operation of a defroster. The traveling state includes a steering angle of the vehicle,
When the vehicle moves backward, the control means is before the reverse starts, and from the point where the steering angle has changed after the vehicle has continued a certain rudder angle for a predetermined time or a predetermined distance. The driving support device according to any one of claims 4 to 7, wherein integration is started or measurement of a yaw angle is started.   The driving support apparatus according to claim 1, wherein the control unit causes the display unit to display an image of either the rear side or the rear side of the vehicle according to the steering angle.   When the vehicle moves backward, the control means keeps the yaw rate of the vehicle at zero for a predetermined time or a predetermined distance before the reverse starts, and then starts accumulating the yaw rate from the changed point. The driving support device according to any one of claims 4 to 7, wherein measurement of a yaw angle is started. A parking end determination means for determining parking end based on a predetermined parking end condition;
The driving support according to any one of claims 1 to 11, wherein the control means causes the display means to display an image of either the rear side or the rear of the vehicle until the parking end is determined. apparatus.   The driving support device according to any one of claims 4 to 12, wherein the control means continues to accumulate the yaw rate or continues to measure the yaw angle until the parking end is determined.   The parking end judging means detects the running state or refers to the past running state from the storage means, and at least turns off the ignition switch, parks the transmission, stops exceeding a predetermined time, and stops for a predetermined time from the present time. There is no detection record of the reverse state of the transmission until before, no detection record of the reverse state of the transmission from the current position on the travel locus to the current position of the vehicle, and a predetermined speed in the forward state The driving support device according to claim 12 or 13, wherein the vehicle is determined to have been parked when any one of the two or more of the traveling states is detected.   The switching means according to any one of claims 1 to 14, further comprising a switching means for manually switching one of the rear side and rear images of the vehicle displayed on the display means to another image. Driving assistance device. A parking space estimating means for recognizing one frame line that is substantially parallel to a traveling direction when the vehicle is parked in the parking space, and estimating the parking space, Prepared,
When the vehicle moves backward and parks in the parking space, the control means is configured to display either the rear side or the rear side of the vehicle according to the parallelism of the traveling direction of the vehicle with respect to the one frame line. The driving support apparatus according to claim 1, wherein: is displayed on a display means.   The said parking space estimation means recognizes this real frame line as said one frame line, when a fixed area | region is divided | segmented by the real frame line drawn on the road of the said parking space, It is the said one frame line. Driving assistance device.   The parking space estimation means estimates a virtual frame line based on a plurality of points on the side surface from an image of the side surface of the other vehicle when another vehicle is parked in the parking space. The driving support device according to claim 16, wherein the virtual frame line is recognized as the one frame line.

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