JP2011016406A - Parking support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking support device allowing a driver to recognize that a vehicle is located at a parkable steering correction position by reversing the vehicle only once in a parking space.SOLUTION: An image of an area behind a vehicle is picked up, and a first path which a vehicle portion on the parking space side traces when the vehicle is linearly reversed while the vehicle is going straight and a second path which the vehicle portion on the parking space side traces when the vehicle is turningly reversed at a predetermined steering angle of a steering wheel different from when the vehicle is linearly reversed are superimposed on a rearward image for display to extend from a rear end of a rear wheel of the vehicle on the parking space side. This display allows a vehicle occupant to recognize that the position of the vehicle when an end nearer to the steering correction position, of both ends of an entrance of a parking space, enters between the first and the second paths is the steering correction position which allows parking by reversing the vehicle once into the parking space.

Description

  The present invention relates to an apparatus for assisting parking of a vehicle.

  Various methods for assisting parking have been proposed in order to reduce the load on the driver when the vehicle is parked. According to the parking assist method described in Patent Document 1 below, when parking, a predicted travel locus is displayed based on the steering angle of the steering, and the white line of the parking section is defined as a predetermined area based on the display position of the predicted travel locus. Detect in window. When a white line exists in the window, the position and direction of the white line are detected, the parking area is verified based on the detection result, and an appropriate notification is given to the driver.

JP 2000-79860 A

  Various methods have been proposed for assisting driving operation in which the vehicle is parked in a predetermined parking space while reversing the vehicle, but most of these methods correspond to the rotation operation of the steering wheel of the vehicle as shown in the above document. A display for displaying a predicted backward trajectory or a line (guide line) indicating the width of the vehicle. The driver parks the vehicle while visually checking the displayed expected trajectory and / or guide line.

  Whether or not the vehicle can be parked by one backward operation when the vehicle is parked in a predetermined parking space while the vehicle is moving backward depends on the position at which the vehicle is turned back from forward to backward. If the turn-back position is inappropriate, it is difficult to complete the parking by a single backward operation even if the above-mentioned expected trajectory or guide line is visually recognized.

  Therefore, when parking in a desired parking space while reversing the vehicle, the parking support can determine whether the driver can complete the parking of the vehicle by one reversing operation at the turn-back position. An apparatus is desired.

  According to one aspect of the present invention, an apparatus for assisting a driving operation in which the vehicle is moved backward and then parked in a desired parking space after the vehicle moves forward captures an image behind the vehicle. An imaging means, a first trajectory followed by a portion on the parking space side of the vehicle when the vehicle is moved straight forward while the vehicle is moving forward, and a predetermined handle different from when the vehicle is moving forward and backward The second rear trajectory followed by the portion of the vehicle on the parking space side when the vehicle is turned backward at a rudder angle of the vehicle starts from the rear end of the rear wheel on the parking space side of the vehicle. Display means for displaying the image superimposed on the image. According to the display by the display means, an occupant of the vehicle can detect the end of the entrance of the parking space when the end closer to the turn-back position is between the first and second trajectories. It can be recognized that the position of the vehicle is the turning-back position where the vehicle can be parked in the parking space by a single backward operation.

  According to the present invention, the driver advances the vehicle so that the end closer to the turn-back position of the entrance of the parking space enters between the first trajectory and the second trajectory. The vehicle can be easily moved within the range of the turn-back position where the parking space can be parked by a single backward operation.

  According to one embodiment of the present invention, the display means further superimposes and displays the predicted backward trajectory of the vehicle according to the steering angle of the vehicle handle when starting the backward movement of the vehicle at the turning-back position.

  According to the present invention, it is possible to more accurately determine whether or not the vehicle can be moved into the parking space by the backward operation according to the current steering angle from the current position of the vehicle by further displaying the predicted backward trajectory. Can be determined.

  Other features and advantages of the present invention will be apparent from the detailed description that follows.

The figure for demonstrating the turnover at the time of parking in a parking space, retreating a vehicle. The block diagram of the parking assistance apparatus according to one Example of this invention. The figure which shows the image display example of the 1st and 2nd locus | trajectory when parking in the parking space on the left side of the vehicle according to one Example of this invention. The figure which shows the image display example of the 1st and 2nd locus | trajectory when parking in the parking space on the right side of the vehicle according to one Example of this invention. The figure which shows the pattern of the positional relationship between the 1st and 2nd locus | trajectory and the reference point of a parking space when parking in the parking space on the left side of the vehicle according to one Example of this invention. The figure which shows the example of a display according to one Example of this invention on which the backward estimated locus | trajectory was further superimposed. The flowchart of the parking assistance process according to one Example of this invention.

  Next, an embodiment of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1, a description will be given of the turnover when the vehicle is parked while moving backward. FIG. 1A shows a state in which the vehicle V parks in the parking space P on the left side toward the head of the vehicle V while moving backward. The vehicle V moves forward from the position A1 as indicated by reference numeral 101, switches from forward to backward at the position A2, and moves backward from the position A2 toward the parking space P as indicated by reference numeral 102. The position A2 is a position where the vehicle is turned back from forward to backward. In order to park the vehicle in the parking space P by one backward operation, the turn-back position needs to be within a predetermined range. .

  For example, referring to (b), it is shown that the vehicle V performs a turn-back at the position A2. Reference numeral 111 indicates a locus of the vehicle body portion on the parking space P side of the vehicle V when the vehicle is moved backward while moving straight, and reference numeral 112 is a case where the handle of the vehicle V is rotated backward to the limit in the left direction. The trajectory of the vehicle body portion on the parking space P side of the vehicle V when the vehicle V is moved backward with the minimum turning radius is shown. As indicated by these trajectories, the vehicle V cannot be parked in the parking space P in any case. That is, no matter what the steering angle of the steering wheel of the vehicle V is, it is difficult to park in the parking space P by one reversing operation. This is because the vehicle does not reach a predetermined range that enables parking by a reverse operation.

  Referring to (c), the vehicle V is turned back at position A2. Similarly to (b), reference numeral 111 indicates a trajectory of the vehicle body portion on the parking space P side of the vehicle V when the vehicle is moved backward while moving straight, and reference numeral 112 indicates the maximum steering in the left direction. A trajectory of the vehicle body portion on the parking space P side of the vehicle V when the vehicle is rotated to the corner and moved backward (that is, when the vehicle V is moved backward with the minimum turning radius) is shown. As indicated by these trajectories, the vehicle V cannot be parked in the parking space P in any case. That is, no matter what the steering angle of the steering wheel of the vehicle V is, it is difficult to park in the parking space P by one reversing operation. This is because the vehicle is overrun with respect to a predetermined range that allows the vehicle to be parked by the reverse operation.

  Thus, whether or not the vehicle can be parked in the parking space P by one reversing operation depends on whether or not the turn-back position is within a predetermined range. This predetermined range is hereinafter referred to as a cut-back range. The present invention supports driving so as to guide the vehicle V within the turning-back range.

  FIG. 2 is a block diagram of an apparatus mounted on a vehicle and supporting parking of the vehicle according to an embodiment of the present invention.

  The imaging device 11 is a device that captures an image behind the vehicle. In this embodiment, the imaging device 11 is a camera attached to the rear center of the vehicle. For example, a CMOS camera and a CCD camera can be used. The captured image is sent to the control unit 21. The steering angle sensor 13 is attached to a steering wheel (steering wheel) of the vehicle and detects a steering angle of the steering wheel. The shift position sensor 15 detects the shift position of the vehicle. Detection signals from these sensors are sent to the control unit 21. The display device 17 is attached so that a vehicle occupant can visually recognize the display device 17.

  In one embodiment, a switch 19 is attached to the vehicle so that the vehicle occupant can operate it. The switch 19 is operated by an occupant when starting parking assist control. When the switch 19 is operated, a signal instructing the start of parking assistance is transmitted to the control unit 21.

  The control unit 21 can be realized in an electronic control unit (ECU) mounted on the vehicle. The ECU is a computer including a central processing unit (CPU) and a memory. In response to receiving a signal instructing the start of parking assistance via the switch 19, the control unit 21 detects an image of the rear of the vehicle imaged by the imaging device 11, the steering angle sensor 13, and the shift position sensor 15. Control of parking assistance is executed using the signal, and the result is displayed on the display device 17.

  The control unit 21 includes a display control unit 23 and a predicted backward trajectory calculation unit 25. As described with reference to FIG. 1A, the display control unit 23 is a vehicle body on the parking space side of the vehicle when the vehicle moves straight back while the vehicle is moving forward toward the turn-back position. The track (referred to as the first track) of the portion (in this embodiment, the portion of the vehicle body on the parking space side (inside) on the extension line of the left and right rear axles, hereinafter the same), and the vehicle Imaging so that the trajectory of the vehicle body portion on the parking space side of the vehicle (referred to as the second trajectory) when reversing while turning at the minimum turning radius starts from the rear end of the rear wheel on the parking space side of the vehicle. The image is superimposed on the image captured by the device 11. Since the trajectory of the vehicle at a predetermined rudder angle is determined in advance, the first trajectory and the second trajectory can be calculated in advance, and an image in which these are drawn can be stored in the memory 31 in advance. Further, since the imaging device 11 is fixed, the position of the rear end of the rear wheel of the vehicle in the captured image is determined in advance. Therefore, the display control unit 23 superimposes the images of the first and second trajectories read from the memory 31 at predetermined positions of the image captured by the imaging device 11 and displays the superimposed image on the display device 17. .

  Referring now to FIG. 3, FIG. 3 (a) shows a form in which the vehicle V is parked while being retracted in the parking space P on the left side toward the head of the vehicle V, which will be described with reference to FIG. As described above, the vehicle V moves forward from the position A1 toward the position A2. At the position A2, the vehicle V switches from moving forward to moving backward, and moves backward from the position A2 to the parking space P. Reference symbol T1 is a left side surface of the vehicle when the vehicle is receded in a straight line (more specifically, as described above, a body portion on the left side of the vehicle on the extension line of the rear wheel axle, (Same as above) shows the first trajectory followed by reference symbol T2, which shows the second trajectory followed by the left side of the vehicle when the vehicle is moved backward while turning at the minimum turning radius.

  (B) is an image obtained by superimposing the images of the first trajectory T1 and the second trajectory T2 on the image captured by the imaging device 11 when the vehicle V is present at the position (a). is there. The rear part of the vehicle V is imaged below the captured image. As described above, since the imaging device 11 is fixed, the positions to be superimposed on the captured images of the first and second trajectories are determined in advance.

  Since FIG. 3 is a form in which the vehicle is parked while moving backward in the parking space on the left side of the vehicle, the first trajectory T1 and the second trajectory T2 are drawn so as to start from the rear end of the left rear wheel of the vehicle. is doing. On the other hand, FIG. 4 shows a form in which the vehicle is parked while retreating in the parking space on the right side of the vehicle. As shown in FIG. 4A, the vehicle V moves forward from position A1 to A2, and moves forward at position A2. From the position A2 toward the parking space P. Also in this case, the first trajectory T1 and the second trajectory T2 are determined in advance. The former is a trajectory followed by the right side surface of the vehicle when the vehicle is moved straight forward, and the latter is the minimum trajectory of the vehicle. This is a trajectory followed by the right side surface of the vehicle when reversing while turning at a turning radius. These trajectories T1 and T2 are drawn on the captured image so as to start from the rear end of the right rear wheel of the vehicle, and are displayed as shown in (b).

  The driver compares the first and second trajectories T1 and T2 with the position of the reference point Y1 of the parking space P. The reference point Y1 is an end point closer to the turn-back position A2 of the vehicle V among the both ends Y1 and Y2 of the entrance of the parking space P. If the reference point Y1 enters between the first and second trajectories T1 and T2, it indicates that the vehicle V is located within a turn-back range that can be parked by one backward operation. Therefore, the driver advances the vehicle so that the reference point Y1 enters between the first and second trajectories T1 and T2, and thereby guides the vehicle within a turn-back range that can be parked by one reverse operation. be able to.

  Referring now to FIG. 5, three examples of the positional relationship between the first and second trajectories T1 and T2 and the reference point Y1 when the parking space P is on the left side of the vehicle V are shown. , (A) to (c), the upper stage shows the parking behavior of the vehicle V, and the lower stage shows a captured image in which the first and second trajectories T1 and T2 are superimposed.

  (A) shows a first example, where the reference point Y1 is not between the first and second trajectories T1 and T2, and the reference point Y1 has not yet appeared in the captured image. This indicates that the vehicle V has not reached the turn-back range that can be parked by one reverse operation. By observing the display, the occupant can recognize that the vehicle V needs to be further advanced so that the reference point Y1 falls between the first and second trajectories T1 and T2.

  (B) shows a second example, which is the same as FIG. The reference point Y1 is between the first and second trajectories T1 and T2. This indicates that the vehicle V is within a turn-back range that can be parked by one reverse operation. The occupant visually recognizes the display and confirms that the reference point Y1 is between the first and second trajectories T1 and T2, thereby recognizing that it is only necessary to switch back at the current position. Can do.

  (C) shows a third example. Although the reference point Y1 appears in the captured image, it does not fall between the first and second trajectories T1 and T2. This indicates that the vehicle V has gone beyond the turn-back range in which the vehicle can be parked with one reverse operation. The occupant can recognize that the vehicle V needs to be moved backward so that the reference point Y1 falls between the first and second trajectories T1 and T2 by visually recognizing the display.

  When the vehicle is moved backward from the turn-back position, the steering wheel is operated between a rudder angle corresponding to rectilinear advance and a rudder angle corresponding to turning backward with a minimum turning radius. Therefore, the presence of the reference point Y1 between the first and second trajectories means that the left rear end of the vehicle V is guided toward the reference point Y1 when the vehicle is moved backward at an arbitrary steering angle. Show that you can. If the left rear end of the vehicle can be guided toward the reference point Y1, the vehicle V may be parked by a single backward operation, although the driver may need to adjust the steering angle slightly. be able to. This is the same when the parking space P is located on the right side of the vehicle.

  When the occupant moves the vehicle forward within an appropriate turn-back range as shown in FIG. 5B above, the occupant stops traveling of the vehicle and changes the shift position from forward to backward.

  Preferably, a predicted reverse trajectory calculation unit 25 (FIG. 2) is provided, and the predicted reverse trajectory calculation unit 25 detects from the steering angle sensor 13 in response to the shift position being changed to reverse as described above. Based on the signal, that is, the current steering angle, an expected trajectory when the vehicle moves backward is calculated. Since the turning radius of the vehicle is determined according to the steering angle, a predicted backward trajectory can be calculated from the detected current steering angle. The display control unit 23 displays the predicted trajectory calculated in this way on the display device 17 by further superimposing it on the captured image. In this embodiment, the predicted backward trajectory is displayed so as to have the width and length of the vehicle.

  The rudder angle changes according to the occupant rotating the steering wheel, and the predicted backward trajectory also changes accordingly. Therefore, the predicted backward trajectory calculation unit 25 updates the predicted backward trajectory according to the steering angle detected at predetermined time intervals, and the display control unit 23 displays the updated predicted trajectory in a superimposed manner.

Referring now to FIG. 6, an example of the predicted backward trajectory R displayed in a superimposed manner is indicated by a dotted line. (A) shows the predicted reverse trajectory R when the steering angle of the steering wheel is a value when the vehicle travels straight forward, and therefore, the parking space side _RL of the vehicle of the predicted reverse trajectory R is the first in the case of a straight forward reverse. Are displayed along the locus T1. (B) shows the predicted reverse trajectory R when the steering wheel is turned to the left as compared with (a), and the vehicle parking space side _RL of the predicted reverse trajectory R passes through the reference point Y1. ing.

In this way, the occupant can confirm where the vehicle will pass with respect to the parking space P when the vehicle retreats by visually recognizing the displayed predicted retreat trajectory R at the turn-back position. . As the steering wheel is rotated, the predicted backward trajectory also changes, so that the occupant can rotate the steering wheel while the position of the reference point Y1 between the displayed predicted backward trajectory and the first and second trajectories. Can be compared. As shown in FIG. 6B, the occupant only has to adjust the steering angle of the steering wheel so that the parking space side _RL of the vehicle on the predicted backward trajectory passes over the reference point Y1. By starting the retreat from the turn-back position at this adjusted steering angle, the vehicle can be retreated so that the parking space side just passes the reference point Y1. Therefore, the vehicle can be reliably guided into the parking space P.

Thus, by calculating and displaying the predicted backward trajectory in accordance with the steering angle of the steering wheel, the occupant can determine the appropriate steering angle of the steering wheel before starting the backward movement. Note that the predicted backward trajectory may be displayed, for example, during the backward movement even after the backward movement is started. Further, in this embodiment, the predicted backward trajectory R is drawn so as to have the vehicle width of the vehicle, but as described with reference to FIG. 6, the trajectory on the parking space side of the vehicle passes the reference point Y1. Therefore, only the locus on the parking space side of the vehicle (in the example of FIG. 6, only the line indicated by _RL ) may be displayed.

  In this embodiment, the second trajectory T2 is a trajectory when turning backward with a minimum turning radius. By doing so, even when the road space facing the parking space is small, the second trajectory T2 is once in the parking space. It becomes easier to guide the vehicle to a turn-back range where parking is possible by a reverse operation. However, in order to move backward with a turning radius different from the minimum turning radius (for example, when there is a parking space on the left side, move backward with a predetermined steering angle different from the maximum steering angle in the left direction), the second The trajectory T2 may be set. In this case, the spread between the first and second trajectories T1 and T2 is narrowed.

  FIG. 7 shows a flow of a process executed by the control unit 21 at predetermined time intervals, specifically, executed by the CPU of the ECU.

  In step S11, it is determined whether or not the parking assist switch 19 (FIG. 2) has been operated. As described above, the switch 19 for parking assistance is operated by the occupant when the vehicle starts to advance toward the turn-back position. If the switch 19 has been operated, the process proceeds to step S12; otherwise, the process is exited.

  In step S12, an image captured by the imaging device 11 is acquired. In step S13, the images of the first and second trajectories are read from the memory, a composite image is created by superimposing these trajectory images on the captured image acquired in step S12, and displayed on the display device 17. . In this way, the captured image on which the first and second trajectories are superimposed is displayed at a predetermined time interval while moving forward toward the switching position. While visually recognizing this image, the driver moves the vehicle forward so that the reference point Y1, which is the end closer to the turn-back position of the entrance of the parking space, falls within the first and second trajectories. The vehicle can be guided within a turn-back range that can be parked by a single backward operation.

  When the reference point Y1 enters the first and second trajectories, the occupant stops traveling of the vehicle and shifts the shift position backward (R). If the vehicle is stopped and the shift position acquired from the detection signal of the shift position sensor 15 (FIG. 2) is reverse, the determination in step S14 is Yes and the process proceeds to step S15. Here, whether or not the vehicle is stopped can be determined based on a detection value of a vehicle speed sensor (not shown).

  In step S15, the steering angle of the steering wheel is acquired from the detection signal of the steering angle sensor 13 (FIG. 2). In step S16, a predicted backward trajectory according to the acquired rudder angle is calculated. In step S17, the calculated predicted backward trajectory is further superimposed on the composite image created in step S13 and displayed on the display device 17. The driver adjusts the steering angle of the steering wheel so that the predicted backward trajectory, more specifically, the trajectory followed by the portion on the parking space side of the vehicle, passes through the reference point Y1, and while maintaining the adjusted steering angle, Start reverse operation. By doing so, the vehicle can be guided into the parking space so that the rear end of the vehicle parking space side passes through the reference point Y1.

  After starting the backward operation, the process may be stopped although not shown in the figure. Thereby, the control process of parking assistance is completed. Alternatively, as described above, the predicted backward trajectory may be displayed while the vehicle is moving backward. At this time, the first and second trajectories may or may not be displayed.

  In the above embodiment, the start of the parking support control is instructed via the switch 19, but the switch may not be a switch as long as the driver can input to the control unit 21. For example, the display device 19 is configured to include a touch panel, and a button on a predetermined screen displayed on the display device is selected via the touch panel to instruct the start of the parking support control. May be.

  As described above, specific embodiments of the present invention have been described. However, the present invention is not limited to these embodiments.

11 imaging device 13 rudder angle sensor 17 display device 21 control unit

Claims (3)

A device for assisting a driving operation in which the vehicle is moved backward and parked in a desired parking space after the vehicle is advanced,
Imaging means for capturing an image of the rear of the vehicle;
While the vehicle is moving forward, when the vehicle is moved straight forward and backward, a first trajectory followed by the portion of the vehicle on the parking space side and a predetermined steering angle different from that when the vehicle is moving forward and backward A second trajectory followed by the portion of the vehicle on the parking space side when the vehicle is turned backward is superimposed on the rear image so as to extend from the rear end of the rear wheel on the parking space side of the vehicle. And display means for displaying,
According to the display by the display means, an occupant of the vehicle can detect the end of the entrance of the parking space when the end closer to the turn-back position is between the first and second trajectories. It can be recognized that the position of the vehicle is the return position where the vehicle can be parked in the parking space by a single backward operation.
Parking assistance device.   The parking support device according to claim 1, wherein the display means further superimposes and displays a predicted backward trajectory of the vehicle according to a steering angle of the steering wheel of the vehicle when the vehicle starts to reverse at the turn-back position. . It has an input means for the passenger to input an instruction to start parking,
The parking support apparatus according to claim 1 or 2, wherein the display unit performs the display in response to an input of the parking start instruction.

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