JP5617732B2 - Parking assistance device - Google Patents

Description

  The present invention relates to a parking assistance device that performs parking assistance during parallel parking.

  2. Description of the Related Art Conventionally, a parking assist device that facilitates parallel parking by instructing the timing of reverse steering during parking support during parallel parking is known (see, for example, Patent Document 1 and Patent Document 2).

JP 2001-322519 A JP 2000-280823 A

  However, in the conventional parking assistance device, the parking target position and the reverse steering timing are determined in advance, and there is a problem that the driver has little room for selecting the parking target position and the reverse steering timing.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a parking assist device that increases a room for selecting a parking target position and a reverse steering timing.

In order to achieve the above object, according to the present invention, the superimposing means continuously superimposes the guide marks in a direction away from the host vehicle in time series along the expected locus when the host vehicle is stopped. During driving, a guide mark indicating a parking target position when the vehicle is reversely steered at the current position among the guide marks is superimposed.

  According to the present invention, there is an effect that it is possible to increase the room for selecting the parking target position and the reverse steering timing.

The block diagram which shows the structure of the parking assistance apparatus in embodiment of this invention. The figure explaining the prediction locus | trajectory of the own vehicle calculated by the calculating part which is the principal part of FIG. 1 with an image The figure explaining the parking target position of the own vehicle which the calculating part which is the principal part of FIG. 1 calculates with an image The figure explaining the parking target position in the arbitrary positions on the prediction locus | trajectory of the own vehicle which the calculating part which is the principal part of the same FIG. The flowchart figure explaining the parking assistance process by the parking assistance apparatus in embodiment of this invention. The figure explaining the guide mark superimposed by step S3 of FIG. 5 with an image FIG. 5 is a diagram illustrating an image of the guide mark superimposed when the current position of the vehicle is the parking start position in step S7 of FIG. The figure explaining the guide mark superimposed when moving backward from the state of FIG. 7 with an image The figure explaining the guide mark superimposed when moving backward from the state of FIG. 8 with an image The figure explaining the guide mark superimposed when it reverse-steered from the state of FIG. The figure explaining the guide mark superimposed when it arrived at the parking target position from the state of FIG.

  Hereinafter, a parking assistance device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a parking assistance apparatus according to an embodiment of the present invention.

  In FIG. 1, the parking assist device is connected to an imaging unit 101, an image processing unit 102, an image display unit 103, a steering angle sensor 105, a wheel speed sensor 106, a gear position sensor 107, a user operation button 108, and a distance sensor 109. Then, each input signal is acquired. The imaging unit 101, the image display unit 103, the steering rudder angle sensor 105, the wheel speed sensor 106, the gear position sensor 107, the user operation button 108, and the distance sensor 109 may be included in the parking assistance device.

  The imaging means 101 has at least a rear camera and images the rear of the host vehicle. The imaging unit 101 may have a front camera and left and right side cameras to capture the entire periphery of the vehicle.

  The image processing unit 102 includes an image acquisition unit 110, a control unit 111 connected to the image acquisition unit 110, and a storage unit 112 connected to the control unit 111. The control unit 111 includes an image conversion unit 113, an image superimposition unit 114, and a calculation unit 115. The image processing unit 102 superimposes a parallel parking assistance guide mark corresponding to the steering angle of the host vehicle on the captured image around the host vehicle input from the imaging unit 101 and outputs the superimposed image to the image display unit 103. To do.

  The image display means 103 is composed of a navigation device, for example. The image display means 103 is provided in a vehicle visible from the driver's seat. The image display unit 103 displays the superimposed image output from the image processing unit 102.

  A steering angle sensor 105, a wheel speed sensor 106, a gear position sensor 107, a user operation button 108, and a distance sensor 109 are respectively a steering angle signal indicating a steering angle, a vehicle speed signal indicating a vehicle speed of the host vehicle, A gear position state signal indicating the state of the gear position, an input signal indicating a parallel parking assistance instruction command, and a signal indicating a distance from a surrounding object are output to the control unit 111. The user operation buttons 108 include, for example, a touch panel, a remote control, a switch, and operation buttons. Note that the user operation button 108 may be provided on the image display unit 103 when configured with a touch panel.

  The image acquisition unit 110 is configured by a volatile memory such as a buffer memory, for example. The image acquisition unit 110 is connected to the imaging unit 101. The image acquisition unit 110 temporarily stores image data obtained from the captured image input from the imaging unit 101. The image data stored in the image acquisition unit 110 is output to the image conversion unit 113 of the control unit 111.

  The storage unit 112 is configured by a nonvolatile memory such as a flash memory or a ROM (Read Only Memory). The storage unit 112 stores a guide mark indicating a parking target position at the time of parallel parking, various programs for control by the control unit 111, and the like.

  The image conversion unit 113 and the image superimposing unit 114 are configured by an image processing unit such as an ASIC (Application Specific Integrated Circuit). The image conversion unit 113 performs image processing on the captured image input from the image acquisition unit 110, converts the captured image into an image signal that can be displayed on the image display unit 103, and outputs the image signal to the image superimposition unit 114. The image superimposing unit 114 reads the guide mark read from the storage unit 112 in accordance with a command from the arithmetic unit 115, appropriately modifies it, and superimposes it on the captured image. The image superimposing unit 114 outputs the superimposed image created every predetermined time to the image display unit 103.

  The calculation unit 115 is configured by, for example, a VLSI (Very Large Scale Integration) or a CPU (Central Processing Unit). The calculation unit 115 is connected to the steering angle sensor 105, the wheel speed sensor 106, the gear position sensor 107, the user operation button 108, and the distance sensor 109, and performs various calculations based on input signals from each. For example, the calculation unit 115 instructs the image superimposing unit 114 to perform image processing for supporting parallel parking in accordance with a parallel parking instruction from the user operation button 108. In addition, the calculation unit 115 calculates an expected trajectory in the backward direction of the host vehicle and a parking target position for parallel parking based on the steering angle signal input from the steering angle sensor 105. Here, the parking target position means a position when the host vehicle is parallel to the parking start position when reverse steering is performed at a maximum steering angle from a predetermined position on the predicted trajectory in the backward direction of the host vehicle.

  Next, the parking target position at an arbitrary position on the predicted trajectory of the host vehicle calculated by the calculation unit 115 will be described.

  FIG. 2 is a diagram illustrating an image of an expected trajectory of the host vehicle calculated by the calculation unit. FIG. 3 is a diagram illustrating an image of the parking target position of the host vehicle calculated by the calculation unit. FIG. 4 is a diagram illustrating an image of a parking target position at an arbitrary position on the predicted trajectory of the host vehicle calculated by the calculation unit.

  As shown in FIG. 2, the rotation center 202 is located on the extension of the rear wheel axle of the vehicle 201. The rotation center 202 is determined according to the steering angle detected by the steering rudder angle sensor 105. The vehicle 201 moves like the vehicle 204 and makes a circular motion around the rotation center 202. The expected trajectory of the vehicle 201 is represented by the arc 203 at this time. In FIG. 2, the expected trajectory of the arc 203 of the left rear wheel of the vehicle 201 is shown, but the expected trajectory of the right rear wheel is also indicated by an arc. Next, a parking target position when reverse steering is performed at the position of the vehicle 204 will be described.

  As shown in FIG. 3, reverse steering is performed from the position of the vehicle 301. The position of the vehicle 301 corresponds to the position of the vehicle 204 in FIG. The vehicle 301 is reversely steered around the rotation center 302 at the maximum steering angle. At this time, the vehicle 301 performs a circular motion like an arc 303. The position of the vehicle 304 indicates a position when the vehicle 301 is parallel to the parking start position. The position of the vehicle 304 indicates the parking target position. If the position of the vehicle 304 is located between the parked vehicles 305 and 306, the user can park the host vehicle in parallel. In order for the vehicle 301 to be parallel to the parking start position, it is necessary to move the vehicle 301 by the same angle 310 as the deviation angle 309 indicated by the tangent 307 on the side of the vehicle 304 and the tangent 308 on the side of the vehicle 304.

  As described above, the calculation unit 115 can calculate the parking target position at an arbitrary position on the predicted trajectory from the calculated predicted trajectory of the host vehicle.

That is, as shown in FIG. 4, the parking target position is determined. The vehicle 411 stopped at the parking start position is steered so as to have a predetermined steering angle. At this time, the right rear wheel 412 of the vehicle 411 circularly moves with a radius R414 around the rotation center 413 determined by the steering angle. An arc 415 drawn by this circular motion is calculated as an expected trajectory. Then, the vehicle 421 is reversely steered at an arbitrary position on the predicted locus. During reverse steering, the vehicle 421 is moved at a predetermined set steering angle. The predetermined rudder angle is preferably set to the maximum rudder angle. At this time, the right rear wheel 422 of the vehicle 421 circularly moves on the route indicated by the arc 425 with the radius r424 at the rotation center 423 determined by the set steering angle. At this time, the vehicle 421 moves to the position of the vehicle 431 that is the parking target position. The position of the vehicle 431 is equal to the angle θ416 of the arc 415 from the vehicle 411 to the vehicle 421 and the angle θ426 of the arc 425 from the vehicle 421 to the vehicle 431. For this reason, the calculating part 115 can calculate the parking target position of the vehicle 431 according to the position of reverse steering. For example, when the vehicle 411 at the parking start position is set as the origin, the horizontal distance X = (R + r) (1−cos θ) to the vehicle 431 that is the parking target position is indicated, and the vertical distance Y = (R + r) ( 1 + sin θ).

  As described above, the calculation unit 115 can calculate the parking target position when the reverse steering is performed at an arbitrary position on the expected locus corresponding to the steering angle by the steering angle at the parking start position. For example, the calculation unit 115 may calculate the parking target position when the reverse steering is performed at all positions on the predicted trajectory, or when the reverse steering is performed at positions at predetermined intervals on the predicted trajectory. The parking target position may be calculated. Based on the parking target position calculated by the calculation unit 115, the image superimposing unit 114 superimposes a guide mark indicating the parking target position on the captured image.

  Next, parking assistance processing by the parking assistance device will be described.

  FIG. 5 is a flowchart for explaining parking support processing by the parking support device according to the embodiment of the present invention.

  First, as shown in step S <b> 1, at the parking start position, the calculation unit 115 determines whether the vehicle has a parking space and a parking start position from the parking space detected by the distance sensor 109 and the steering angle detected by the steering angle sensor 105. Recognize the misalignment angle. Normally, in parking support for parallel parking, it is desirable that the parking start position and the parking space be parallel to each other, but the calculation unit 115 corrects the parking support guidance according to this deviation angle by a known method. For example, the technique disclosed in JP-A-2005-132180 can be used. For example, when it is determined that the vehicle speed detected by the wheel speed sensor 106 has stopped at a predetermined value or less, the calculation unit 115 determines that the host vehicle is located at the parking start position.

  Next, as shown in step S <b> 2, the calculation unit 115 recognizes the steering angle from the steering angle sensor 105. This steering rudder angle means a steering rudder angle that is operated while the vehicle is stopped at the parking start position.

  Next, as shown in step S3, based on the steering angle recognized in step S2, the image superimposing unit 114 superimposes a guide mark indicating the parking target position on the captured image in time series. That is, as shown in FIG. 4, the calculation unit 115 calculates the parking target position when the vehicle is reversely steered at an arbitrary position on the expected trajectory according to the steering angle detected by the steering angle sensor 105. . And the image superimposition part 114 superimposes the guide mark which shows this parking target position input from the calculating part 115 in time series. For example, the image superimposing unit 114 continuously superimposes guide marks one by one in a direction away from the host vehicle. Further, the image superimposing unit 114 may superimpose a plurality of guide marks, and sequentially switch the emphasis state one by one in the direction away from the host vehicle.

Next, as shown in step S <b> 4, the calculation unit 115 determines whether or not the start of reverse of the vehicle is detected based on the reverse signal from the gear position sensor 107. If NO in step S4, the process of step S2 is performed again.

  On the other hand, if YES in step S4, as shown in step S5, the image superimposing unit 114 erases the guide mark superimposed on the captured image by a command from the arithmetic unit 115. In addition, the image superimposing unit 114 stores all guide marks superimposed on the captured image in the storage unit 112. This guide mark is associated with an arbitrary reverse steering position on the predicted trajectory calculated in step S3.

  Next, as shown in step S6, the calculation unit 115 recognizes the deviation angle between the parking space and the vehicle body as in step S1.

  Next, as shown in step S7, the image superimposing unit 114 superimposes a guide mark corresponding to the current position of the vehicle on the captured image. The calculation unit 115 calculates the current position of the vehicle that is moving backward from the parking start position from the steering angle and the vehicle speed acquired from the steering angle sensor 105 and the wheel speed sensor 106. The image superimposing unit 114 reads one reverse steering position corresponding to the current position input from the calculation unit 115 from the storage unit 112. Then, the image superimposing unit 114 reads the guide mark corresponding to the read reverse steering position from the storage unit 112 and superimposes it on the photographed image.

  Next, as shown in step S8, the calculating part 115 determines whether the parking completion was detected. Specifically, the calculation unit 115 detects the completion of parking when the steering rudder angle detected by the steering rudder angle sensor 105 and the vehicle speed detected by the wheel speed sensor 106 are both zero or a predetermined threshold value near zero. It is determined that In the case of NO in step S8, the calculation unit 115 determines that the vehicle is continuing the parallel parking and performs the process of step S6 again.

  On the other hand, in the case of YES in step S8, the calculation unit 115 instructs the image superimposition unit 114 to end parking assistance.

  Next, an image of the guide mark superimposed on the captured image by the parking support process shown in FIG. 5 will be described.

  FIG. 6 is a diagram for explaining the guide marks superimposed in step S3 as an image.

  In FIG. 6, overhead images 510 to 515 obtained by converting the captured images around the vehicle captured by the imaging unit 101 by the image conversion unit 113 into the overhead viewpoints are shown. In the bird's-eye view images 510 to 515, a vehicle 520 stopped at the parking start position, a front parked vehicle 521, and a rear parked vehicle 522 are shown.

  In FIG. 6, guide marks 523 to 525 at the steering angle φ1 are superimposed on the overhead images 510 to 512, respectively. In the superimposed images 513 to 515, guide marks 526 to 528 at the steering angle φ2 are superimposed, respectively. Here, the steering angle φ1 <φ2.

  Guide marks 523 to 525 indicate parking target positions when the vehicle is reversely steered at a predetermined position on the expected trajectory of the vehicle 520 at the steering rudder angle φ1. Guide marks 526 to 528 indicate parking target positions when the vehicle is reversely steered at a predetermined position on the expected locus of the vehicle 520 when the steering angle is φ2.

As indicated by the guide mark 523 of the overhead image 510, the guide mark 524 of the overhead image 511, and the guide mark 525 of the overhead image 512, the guide marks 523 to 525 are superimposed in time series. Similarly, the overhead images 513 to 515 and the guide marks 523 to 525 are superimposed in time series. These superimposed images are output to the image display means 103 and displayed.

  From the above, if the user performs a steering operation, the user can check a set of a plurality of parking target positions every predetermined time without any other operation. Therefore, before starting parking, the user can check how much room to select the parking target position indicating whether or not parking is possible at the current steering angle and the timing of reverse steering.

  FIG. 7 is a diagram illustrating the guide mark superimposed when the current position of the vehicle is the parking start position in step S7. FIG. 8 is a view for explaining the guide marks superimposed when the vehicle is moved backward from the state shown in FIG. FIG. 9 is a view for explaining the guide marks superimposed when the vehicle is moved backward from the state shown in FIG. FIG. 10 is a view for explaining the guide marks superimposed when the vehicle is reversely steered from the state of FIG. FIG. 11 is a diagram illustrating an image of the guide mark superimposed when the parking target position is reached from the state of FIG.

  7 to 11, a composite image obtained by combining the captured image with the overhead viewpoint by the image conversion unit 113 and a rear captured image behind the vehicle are illustrated. 7 to 11, a guide mark 601 indicating a parking target position when the vehicle is reversely steered at the current position and a graphic of the host vehicle 602 are superimposed. Further, in the rear captured images of FIGS. 7 to 11, a guide mark 611 indicating the parking target position when the vehicle is reversely steered at the current position is shown. A guide mark 611 on the rear captured image corresponds to the guide mark 601 of the composite image. The front parked vehicle 603 and the rear parked vehicle 604 on the composite image correspond to the front parked vehicle 613 and the rear parked vehicle 614 on the rear captured image, respectively.

  When the backward start is detected as shown in step S4, the image display means 103 switches from the display of FIG. 6 to the display of FIG. Then, the user drives toward the parking space between the front parked vehicle 613 and the rear parked vehicle 614. According to the user's operation, the display on the image display means 103 is switched in the order of FIGS. As shown in FIGS. 7 to 9, the parking target position indicated by the guide mark 601 moves with the movement of the host vehicle 602. This parking target position corresponds to the parking target position calculated by the calculation unit 115 in step S3. That is, in step S3, the calculation unit 115 calculates the parking target position when the vehicle is reversely steered at an arbitrary position on the expected locus. The calculation unit 115 sets the current position of the host vehicle 601 to an arbitrary position on the predicted locus. Then, the image superimposing unit 114 reads out the parking target position corresponding to the current position of the host vehicle 601 from the storage unit 112, adds the enlargement rate and the rotation rate, and superimposes them on the composite image and the captured image.

  Next, as shown in FIG. 9, the guide mark 601 is located between the front parked vehicle 603 and the rear parked vehicle 604 on the composite image due to the user's driving in the backward direction. On the captured image, the guide mark 611 is in the parking space. At this time, the user performs reverse steering. Then, the calculation unit 115 determines that reverse steering has been performed based on the steering angle that is input from the steering angle sensor 105.

  The calculation unit 115 performs the same process even after determining that there has been reverse steering. As a result, it is possible to dynamically cope with the case where the user loosens the rudder angle in the middle of reverse of the vehicle by reverse steering.

If the user continues to reverse the vehicle in the state of reverse steering, the guide mark 601 is displayed as if fixed on the display screen. That is, as shown in FIGS. 9 to 11, even when the user moves the vehicle 602, the image superimposing unit 114 superimposes a guide mark indicating the parking target position at the position when the reverse steering is performed. As described above, before reverse steering is performed, as shown in FIGS. 7 to 9, if the host vehicle is reversely steered at the current position, the user can be guided to the parking target position, and the reverse steering is performed. After being broken, as shown in FIGS. 9 to 11, it is possible to guide the user that the own vehicle only needs to be stopped at the parking target position.

  As described above, according to the parking assist device of the present invention, when the host vehicle is stopped, the guide marks are superimposed in time series along the expected trajectory, and when the host vehicle is being driven, Among them, a guide mark indicating the parking target position when the vehicle is reversely steered at the current position is superimposed, so that it is possible to provide a parking assist device that increases the room for selecting the parking target position and the timing of reverse steering.

  The parking assistance apparatus of the present invention is useful as a parking assistance during parallel parking.

DESCRIPTION OF SYMBOLS 101 Image pickup means 103 Image display means 105 Steering angle sensor 114 Image superimposition part 115 Calculation part

Claims (4)

Imaging means for imaging the surroundings of the vehicle;
Rudder angle detection means for detecting the rudder angle of the host vehicle;
Based on the rudder angle detected by the rudder angle detecting means, a predicted trajectory of the host vehicle is calculated, and a parking target position where the rudder angle detected by the rudder angle detecting means is zero when the steering is reversed on the predicted trajectory is determined. Computing means for computing;
A superimposing unit that superimposes a guide mark indicating a parking target position calculated by the calculating unit on a captured image captured by the imaging unit;
The superimposing means continuously superimposes the guide marks in a direction away from the host vehicle in time series along the predicted trajectory when the host vehicle is stopped. A parking assist device, wherein a guide mark indicating a parking target position when the vehicle is reversely steered at a current position is superimposed.   The parking support apparatus according to claim 1, further comprising display means for displaying a superimposed image superimposed by the superimposing means.   The parking assist device according to claim 2, wherein when the host vehicle is reversely steered, the superimposing unit continuously superimposes a guide mark indicating a parking target position at that position. It further comprises vehicle speed detection means for detecting the vehicle speed,
The superimposing means corrects and superimposes a guide mark indicating a parking target position at a position where the host vehicle is reversely steered based on the steering angle detected by the steering angle detecting means and the vehicle speed detected by the vehicle speed detecting means. The parking support apparatus according to claim 3, wherein