JP2008213647A - Parking assist method and parking assist system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parking assist method and a parking assist system that can instantly grasp the relative positions of a vehicle and a parking frame. <P>SOLUTION: In a parking assist unit 2 which displays the images of the vehicle periphery on a display 5, a composite image indicating the vehicle periphery is outputted to the display 5 and an image of the vehicle of the composite image is drawn at a position corresponding to the present position of the vehicle. Furthermore, the composite image is drawn by fixing the target parking frame to a predetermined position at least when the vehicle approaches a target parking frame, and the image of the vehicle is moved on the composite image with the reverse movement of the vehicle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a parking assistance method and a parking assistance device.

  2. Description of the Related Art Conventionally, parking assist devices that display an image of the rear of a vehicle on a display are known. This device inputs image data from a vehicle-mounted camera attached to the rear end of the vehicle, and outputs a peripheral image based on the image data to a display provided in the vicinity of the driver's seat together with a guide line (for example, see Patent Document 1). ).

In the surrounding image, a road surface and an obstacle within a predetermined distance range from the own vehicle are displayed, and an own vehicle image is displayed. The own vehicle image is an image drawn based on a part of the vehicle body included in the angle of view of the in-vehicle camera or the vehicle image data stored in advance by the parking support device, and is the current position of the own vehicle among the surrounding images. It is fixed and displayed at the corresponding position. When the white line that partitions the parking frame is displayed in the surrounding image, the driver can perform the steering operation while grasping the relative position between the white line and the vehicle.
JP 2006-256419 A

  However, in the above-described device, the host vehicle image is fixed and displayed, and the surrounding image changes as the host vehicle moves backward, so that the relative position between the host vehicle and the parking frame may be difficult to understand depending on the driver. For example, when the vehicle turns to the left rear, the road surface drawn by the surrounding image changes from a road surface that can be photographed by the in-vehicle camera at the current position to a road surface that can be photographed by the in-vehicle camera at the position after the turn. . For this reason, when the own vehicle starts entering the parking frame, even if a white line is displayed in the surrounding image, the white line moves within the screen. Therefore, the vehicle position with respect to the parking frame marked on the road surface may not be immediately grasped.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a parking support method and a parking support device that can immediately grasp the relative position between the host vehicle and the parking frame.

  In order to solve the above problem, the invention according to claim 1 is a parking support method for displaying an image around a vehicle on a display means, wherein the vehicle surrounding image is output to the display means, The vehicle image is drawn at a position corresponding to the current position of the vehicle, and when the vehicle approaches the parking frame, the parking frame is fixed at a predetermined position to draw the vehicle peripheral image, and the vehicle The gist is to move the vehicle image on the vehicle periphery image as the vehicle moves backward.

  According to a second aspect of the present invention, in the parking assist device for displaying an image around the vehicle on the display means, a surrounding image drawing means for outputting the vehicle surrounding image to the display means, and the vehicle surrounding image out of the vehicle surrounding images. Vehicle image drawing means for drawing the vehicle image at a position corresponding to the current position; and when the vehicle approaches the parking frame, the parking frame is fixed at a predetermined position to draw the vehicle peripheral image, The gist of the present invention is that it includes drawing switching means for moving the vehicle image on the vehicle peripheral image as the vehicle moves backward.

According to a third aspect of the present invention, in the parking assist device according to the second aspect, the drawing switching unit is configured such that when the entire area of the parking frame is included in the image display range of the display unit, the parking frame The gist of the present invention is to draw the vehicle peripheral image drawn with the position fixed at a predetermined position.

  According to a fourth aspect of the present invention, in the parking assist device according to the second or third aspect, the drawing switching means is configured such that the parking frame displayed in the vehicle peripheral image is parallel to the vehicle. In this case, the gist is to draw the vehicle periphery image drawn with the parking frame fixed at a predetermined position.

  According to a fifth aspect of the present invention, in the parking assist device according to any one of the second to fourth aspects, the drawing switching means sets the display position of the parking frame to the lower center of the image display range. The gist is to display the vehicle periphery image in a state.

  According to the first aspect of the present invention, when the vehicle approaches the parking frame, the vehicle peripheral image is displayed with the parking frame fixed at a predetermined position. For this reason, as the vehicle moves backward, the vehicle image moves to the fixed eye parking frame, so that the driver can feel a sense of incongruity and display a screen that can immediately understand the relative position between the vehicle and the target parking frame. be able to.

  According to the second aspect of the present invention, when the vehicle approaches the parking frame, the surrounding image of the vehicle is displayed with the parking frame fixed at a predetermined position by the parking assist device. For this reason, as the vehicle moves backward, the vehicle image moves to the fixed target parking frame, so that the driver can immediately feel the relative position between the vehicle and the target parking frame without feeling uncomfortable. be able to.

  According to the third aspect of the present invention, when the entire area of the parking frame is included in the image display range, the parking frame is fixed at a predetermined position and drawn. For this reason, the screen centering on the parking frame can be displayed at an appropriate timing.

  According to the fourth aspect of the present invention, when the parking frame displayed in the vehicle periphery image is parallel to the own vehicle image, the parking frame is fixed at a predetermined position and drawn. For this reason, the screen centering on the parking frame can be displayed at an appropriate timing.

  According to the fifth aspect of the present invention, the parking frame is displayed in the lower center of the image display range, so that it is possible to display a screen that makes it easy to see the vehicle moving backward toward the parking frame.

(First embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the parking assistance system 1. The parking assistance system 1 has a parking assistance unit 2 as a parking assistance device. The parking assist unit 2 includes a vehicle position calculation unit 10, an input interface (I / F) 11, an image input unit 12, an overhead view conversion unit 13 as a peripheral image drawing unit, an overhead data storage unit 14, a peripheral image drawing unit, An image composition unit 15 as a vehicle image drawing unit, a parking frame recognition unit 16, an expected trajectory line calculation unit 17, and an image fixing control unit 18 as a drawing switching unit are provided.

The own vehicle position calculation unit 10 inputs a vehicle speed pulse and a direction detection signal from the vehicle speed sensor 20 and the gyro 21 and calculates a movement distance and a movement direction from the reference position. The image input unit 12 controls the camera 25 attached to the rear end of the host vehicle C (see FIG. 2) to perform shooting. The camera 25 is mounted on the rear side of the vehicle so as to be capable of photographing a predetermined distance range from the rear end of the vehicle. When a shift position signal indicating reverse is input from a neutral start switch 22 provided in the host vehicle C, the image input unit 12 controls the camera 25 to perform shooting. Further, based on the own vehicle position calculation unit 10, shooting is performed at a predetermined timing while the own vehicle C is moving backward, and image data G is acquired.

  The overhead view conversion unit 13 acquires the image data G from the image input unit 12 and performs coordinate conversion. Specifically, the coordinates of each pixel of the image data G are converted into the coordinates of the conversion destination linked by the overhead view conversion table with reference to the previously stored overhead view conversion table. Thereby, the image data G photographed from the camera viewpoint is converted into the bird's-eye view data G1 obtained by bird's-eye view of the road surface from the viewpoint set at a position vertically above the road surface.

  When the overhead data G <b> 1 is generated, the overhead conversion unit 13 writes the overhead data G <b> 1 in the overhead data storage unit 14. At this time, the bird's-eye conversion unit 13 writes the bird's-eye view data G1 in an area corresponding to the vehicle position where the bird's-eye view data G1 is captured in the memory area secured in advance. Further, when the host vehicle C moves backward, overhead data G1 in which road surfaces in different areas are drawn is generated each time. For this reason, the bird's-eye view conversion unit 13 synthesizes the bird's-eye view data G1 by writing each bird's-eye view data G1 in which different regions are drawn in different regions. As the number of the overhead view data G1 thus written increases, road surface data around the vehicle is accumulated in the overhead view data storage unit 14.

  The image composition unit 15 reads the bird's-eye view data G1 stored in the bird's-eye view data storage unit 14, and synthesizes the bird's-eye view data G1 and image data G newly acquired from the camera 25 (hereinafter referred to as current image data G2). Then, synthetic data G3 as shown in FIG. 2 is generated. When reading the bird's-eye view data G1, the image composition unit 15 reads the bird's-eye view data G1 in the area corresponding to the blind spot of the current camera 25, and synthesizes the bird's-eye view data G1 and the current image data G2. When the composite data G3 is generated, the image composition unit 15 outputs the composite data G3 to the display 5 as display means. As a result, a composite image 33 composed of the past image 31 based on the overhead view data G1 and the current image 32 based on the current image data G2 is displayed. In the composite image 33, white lines and obstacles marked on the road surface are displayed.

  Further, as shown in FIG. 2, the image composition unit 15 outputs vehicle image data 15a (see FIG. 1) to a predetermined position corresponding to the current position of the host vehicle C in the composite data G3, and the host vehicle image. 35 is displayed. In the present embodiment, the vehicle image 35 is displayed at an initial position in the upper center of the image display range R.

  The parking frame recognition unit 16 recognizes the parking frame by a known processing method based on the overhead view data G1 or the current image data G2. For example, edge detection may be performed on the overhead view data G1 or the current image data G2, and a region surrounded by a pair of parallel edges may be used as a parking frame. Alternatively, a parking lot map of each place is stored in a storage unit (not shown), the parking lot map corresponding to the vehicle position is read, the parking lot map and the vehicle location are referred to, and a parking frame around the vehicle is detected. May be. Alternatively, template matching may be performed using the parking lot map and the overhead view data G1 or the current image data G2 to detect parking frames around the vehicle. Alternatively, the other vehicle may be recognized based on the overhead view data G1 or the like, and the space where the other vehicle is parked and the empty space between the other vehicles may be recognized as the parking frame.

  Moreover, the parking frame recognition part 16 sets the target parking frame F1 into which the own vehicle C enters. For example, in the touch panel display 5, when a parking frame is designated on the screen by a user operation, the designated parking frame is set as the target parking frame F1. Or it is good also considering the parking frame F close | similar to the estimated locus line of the own vehicle C among the recognized parking frames F based on the steering angle of the own vehicle C as the target parking frame F1.

The predicted trajectory line calculation unit 17 draws an expected trajectory line on the composite image 33 by a known processing method. For example, a steering value is acquired from the steering sensor 23, and this steering value is converted into a front wheel steering angle. Further, the turning radius is calculated from the front wheel rudder angle and the length of the wheel base, and the turning center point is specified from the turning radius. Further, the distance from the turning center point to each rear wheel is set as the turning radius of each rear wheel, and the representative point of the expected trajectory line of each rear wheel is calculated around the turning center point. When the coordinates of the representative points are calculated, the predicted trajectory line calculation unit 17 draws an expected trajectory line 36 drawn between each representative point with a curve or a straight line on the composite image 33.

  The image fixing control unit 18 displays the composite image 33 in a state where the target parking frame F1 is fixed at a predetermined parking frame drawing position at a predetermined timing based on the display state of the display 5 of the target parking frame F1. More specifically, first, the image fixing control unit 18 acquires the coordinates of the end points P1 to P4 indicating the four corners of the target parking frame F1 based on the parking frame recognition unit 16. Further, it is determined whether the end points P1 to P4 are all included in the image display range R indicating the drawing range of the display 5 as the host vehicle C moves backward. In the present embodiment, it is determined whether or not each of the end points P1 to P4 is included in the image display range R, but in short, whether or not the entire area of the target parking frame F1 is included in the image display range R. Can be determined, and it may be determined whether or not all the edges EG indicating the target parking frame F1 are included in the image display range R.

As shown in FIG. 3, when it is determined that the end points P1 to P4 are all included in the image display range R, the entry point of the target parking frame F1 is used in the image coordinate system (x, y) using the composite data G3. The coordinates (x ₁ , y ₁ ) of the front end center point Pa are acquired. Further, the coordinates (x ₂ , y ₂ ) of the center point Pb at the rear end of the target parking frame F1 are calculated. Further, a relative angle θ formed by the center line LF of the target parking frame F1 passing through the center points Pa and Pb and the center line LC of the host vehicle C (vehicle image) is calculated. Formula (1) can be used to calculate the relative angle θ. However, when “y ₂ −y ₁ = 0”, Δθ is 180 ° (x ₁ <x ₂ ) or −180 ° (x ₁ > x ₂ ).

尚、本実施形態では、目標駐車枠Ｆ１の中心線ＬＦと、自車両Ｃの中心線ＬＣとがなす相対角度θを算出するようにしたが、目標駐車枠Ｆ１の中心線ＬＦの替わりに、駐車枠縦線、駐車枠横線を用いるようにしてもよい。また、中心線ＬＦの替わりに、自車両Ｃの中心線ＬＣ以外に、画面の縦軸（ｙ軸）又は横軸（ｘ軸）、車軸、後端接線を用いるようにしてもよい。

In the present embodiment, the relative angle θ formed by the center line LF of the target parking frame F1 and the center line LC of the host vehicle C is calculated, but instead of the center line LF of the target parking frame F1, A parking frame vertical line and a parking frame horizontal line may be used. Further, instead of the center line LF, in addition to the center line LC of the host vehicle C, the vertical axis (y axis) or horizontal axis (x axis) of the screen, the axle, and the rear end tangent may be used.

When the relative angle θ of the target parking frame F1 with respect to the host vehicle C is calculated, the vehicle image data 15a, the predicted trajectory line 36, and the combined data G3 are translated in order to place the target parking frame F1 in the center of the lower end of the image display range R. And rotating. That is, a parallel movement is performed in which the center point Pb at the rear end of the parking frame is moved to the origin of the image display range R. Further, the synthesized data G3 is rotated by a relative angle θ about the center point Pb positioned at the origin (0, 0). Further, the parallel movement for moving the center point Pb to the center of the lower end of the image display range R is performed again. This series of image processing can be converted using Equation (2). Here, x _max and y _max are the maximum values of the x coordinate and y coordinate of the image display range R. Further, dx = −x ₂ and dy = −y ₂ .

これにより、図４中実線で示すように、目標駐車枠Ｆ１が画像表示範囲Ｒの下方中央の駐車枠描画位置に配置され、その変換にあわせて、車両画像データ１５ａ、予想軌跡線３６及び合成データＧ３が座標変換される。このように、目標駐車枠Ｆ１の端点Ｐ１〜Ｐ４が画像表示範囲Ｒ内に含まれている場合は、自車両Ｃの舵角及び移動量に合わせて上記した座標変換を行い、常に目標駐車枠Ｆ１を画像表示範囲Ｒの下方中央に設定された駐車枠描画位置に配置する。

As a result, as shown by the solid line in FIG. 4, the target parking frame F1 is arranged at the parking frame drawing position at the lower center of the image display range R, and in accordance with the conversion, the vehicle image data 15a, the expected trajectory line 36, and the composition. Data G3 is coordinate-transformed. As described above, when the end points P1 to P4 of the target parking frame F1 are included in the image display range R, the coordinate conversion described above is performed according to the steering angle and the movement amount of the host vehicle C, and the target parking frame is always set. F1 is arranged at the parking frame drawing position set at the lower center of the image display range R.

  Next, the processing procedure of this embodiment is demonstrated according to FIGS. As shown in FIG. 5, when parking assistance is started, the parking assistance unit 2 initializes the system (step S1) and determines the presence or absence of a start trigger (step S2). In the present embodiment, the start trigger is a shift position signal that is an electrical signal generated by switching the shift lever of the host vehicle C, and is a signal indicating reverse.

  If it is determined that the start trigger is input (YES in step S2), the parking frame recognition unit 16 determines whether or not the target parking frame F1 has been set (step S3). Immediately after the start trigger is input, it is determined that the target parking frame F1 is not set (NO in step S3), and the target parking frame F1 is set (step S4). At this time, as described above, when a parking frame is designated on the screen by the user's operation, the designated parking frame is set as the target parking frame F1, or the predicted locus line 36 is calculated and recognized parking. Among the frames F, the parking frame F close to the expected trajectory line 36 is set as the target parking frame F1.

  When the target parking frame F1 is set by a user input operation, for example, the image data G is input from the camera 25 by the image input unit 12, and an image based on the image data G is displayed by the image composition unit 15. At this time, the image data G may be overhead converted by the overhead conversion unit 13. Further, when a touch panel operation for designating a predetermined position of the image is performed by the user, the detection unit (not shown) of the display 5 detects the contact position of the finger and outputs the contact position to the parking frame recognition unit 16. The parking frame recognition unit 16 refers to the output image data G and the contact position, and sets the position designated by the user as the target parking frame F1. When setting the target parking frame F1 based on the expected trajectory line 36, for example, the parking frame recognition unit 16 acquires the image data G from the camera 25, performs edge detection on the image data G, and partitions the parking frame. Recognize white lines When a plurality of parking frames are recognized, the predicted trajectory line calculation unit 17 calculates an expected trajectory line 36 corresponding to the current steering angle, and sets a parking frame close to the predicted trajectory line 36 as the target parking frame F1. To do.

  When the target parking frame is set, camera image capture processing is performed by the image input unit 12, the overhead conversion unit 13, and the image composition unit 15 (step S5). This camera image capturing process will be described with reference to FIG. As shown in FIG. 6, the image input unit 12 controls the camera 25 to acquire image data G obtained by photographing the rear of the vehicle (step S5-1).

  The overhead conversion unit 13 performs coordinate conversion of the acquired image data G using the overhead conversion table as described above (step S5-2). Thereby, the bird's-eye view data G1 is generated by bird's-eye view of the road surface from the viewpoint vertically above the road surface.

  Moreover, the overhead view conversion unit 13 writes the generated overhead view data G1 in the overhead view data storage unit 14 (step S5-3). At this time, as described above, the overhead view data G1 is written in the area corresponding to the position where the overhead view data G1 is photographed in the memory area of the overhead view data storage unit 14.

  Furthermore, the image composition unit 15 performs drawing processing using the overhead view data G1 (step S5-4). At this time, as described above, for example, a predetermined area that is the blind spot of the current camera 25 is extracted from the overhead view data G1 written in the overhead view data storage unit 14. Further, the extracted data and the current image data G2 are combined to generate combined data G3. Also, the vehicle image 35 based on the vehicle image data 15a is drawn at the initial drawing position in the image display range R. As a result, the composite image 33 is displayed on the screen of the display 5 as shown in FIG.

  When the camera image capturing process is completed in this way, as shown in FIG. 5, the predicted trajectory line calculation unit 17 performs the predicted trajectory line drawing process as described above (step S6). As a result, the expected trajectory line 36 is superimposed on the composite image 33 as shown in FIG.

  Further, the image fixing control unit 18 performs an image fixing process (step S7). This image fixing process will be described with reference to FIG. The image fixing control unit 18 determines whether or not the target parking frame F1 is included in the image display range R based on the parking frame recognition unit 16 (step S7-1). At this time, for example, the parking frame recognition unit 16 acquires the coordinates of the end points P1 to P4 of the target parking frame F1 set in step S4, and the end points P1 of the four corners of the target parking frame F1 as the host vehicle C moves. It is determined whether or not P4 is included in the image display range R. Alternatively, when the composite data G3 and the parking lot map are compared and matching is performed, and the same target parking frame as the parking lot map described above is detected in the image display range R, the target parking frame F1 is within the image display range R. You may make it judge that it is contained in.

  If it is determined that the target parking frame F1 is included in the image display range R (YES in step S7-1), as described above, the image fixing control unit 18 uses the target parking frame F1 in the image coordinate system (x, y). And the relative angle θ formed by the target parking frame F1 and the host vehicle C is calculated (step S7-2). At this time, as described above, the coordinates of the center point Pb at the rear end of the target parking frame F1 and the coordinates of the center point Pa at the front end are acquired as the position of the target parking frame F1 (see FIG. 3). Further, a relative angle θ formed by the center line LF of the target parking frame F1 passing through the center points Pa and Pb and the center line LC of the host vehicle C (vehicle image) is calculated.

  Furthermore, the image fixing control unit 18 performs parallel movement and rotational movement around the target parking frame F1 (step S7-3). At this time, as described above, the parallel movement for moving the center point Pb at the lower end of the target parking frame F1 to the origin (0, 0) is performed on the vehicle image data 15a, the expected trajectory line 36, and the combined data G3. Further, the vehicle image data 15a, the predicted trajectory line 36, and the combined data G3 are rotated and moved by a relative angle θ around the center point Pb positioned at the origin. Furthermore, a parallel movement is performed in which the center point Pb at the origin (0, 0) is arranged at the center of the lower end of the image display range R.

When the parallel movement and the rotational movement are performed, an image included in the image display range R of the display 5 is drawn out of the vehicle image data 15a, the predicted trajectory line 36, and the combined data G3 that are translated and rotated (step S7-4). ). Thereby, as shown in FIG. 4, the composite data G3 outside the image display range R is not displayed. In addition, as shown by the hatched portion in FIG. 4, a region in the image display range R where the composite data G3 is not written may be hidden, or corresponding data among the overhead view data G1 and the current image data G2. May be newly written. As a result, as shown in FIG. 8B, the parking assistance screen 40 in which the target parking frame F <b> 1 is displayed in the parking frame drawing position in the image display range R is displayed on the display 5.

  When the image fixing process is completed, the parking support unit 2 determines whether or not there is an end trigger (step S8). The end trigger is a shift position signal indicating a shift position other than reverse. If the host vehicle C is moving backward, it is determined that an end trigger is not input (NO in step S8), the process returns to step S3, and it is determined whether or not the target parking frame F1 has been set (step S3). . At this time, since the target parking frame F1 has already been set (YES in step S3), the process proceeds to step S5 and the above-described processing is repeated.

  The image fixing control unit 18 fixes the composite image 33 in a state where the target parking frame F1 is fixed at the parking frame drawing position while the entire target parking frame F1 is included in the image display range R. For this reason, even if the own vehicle C reaches a position closer to the target parking frame F1 from the position shown in FIG. 8B as shown in the parking assistance screen 40 shown in FIG. , And the composite image 33 is displayed with the drawing range fixed. At this time, since at least a part of the composite image 33 has been updated using the latest current image data G2, when a moving obstacle enters a predetermined area behind the vehicle, the moving obstacle is displayed in the composite image 33. Is done.

  Further, as shown in FIG. 8D, even if the host vehicle C enters the target parking frame F1, the composite image 33 is fixed. When the host vehicle C goes straight backwards, it looks as if it is a bird's-eye view of entering the host vehicle C into the target parking frame F1 marked on the road surface, so that the driver does not feel uncomfortable. The position and the deviation from the white line can be grasped.

According to the first embodiment, the following effects can be obtained.
(1) In the first embodiment, when the host vehicle C approaches the target parking frame F1, the composite image 33 is displayed with the target parking frame F1 fixed at a predetermined parking frame drawing position. Therefore, as the host vehicle C moves backward, the host vehicle image 35 moves to the fixedly displayed target parking frame F1, so that the driver does not feel uncomfortable and the relative position between the host vehicle C and the target parking frame F1. Can be displayed immediately.

  (2) In the first embodiment, when the entire area of the target parking frame F1 is included in the image display range R, the target parking frame F1 is fixed and drawn at the parking frame drawing position. That is, the drawing position of the target parking frame F1 can be fixed when the own vehicle C approaches the target parking frame F1, instead of fixing before the own vehicle C approaches the target parking frame F1. For this reason, since the composite image 33 is fixed when the relative position between the target parking frame F1 and the host vehicle C is grasped and the steering is finely adjusted, the image can be fixed at an accurate timing.

  (3) In the first embodiment, the parking frame drawing position is set at the lower center of the image display range R. For this reason, the space which the own vehicle image 35 can move within a screen is ensured, and the screen which is easy to see a host vehicle C retreating toward the target parking frame F1 can be displayed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. Since the second embodiment has a configuration in which the image fixing timing of the first embodiment is changed, detailed description of the same parts is omitted.

In the second embodiment, first, similarly to the first embodiment, the image fixing control unit 18 determines whether or not the target parking frame F1 is included in the image display range R. When it is determined that the entire area of the target parking frame F1 is included in the image display range R, the position of the target parking frame F1 and the relative angle θ are calculated as described above, and whether or not the relative angle θ is near 0 °. Judging. Further, when it is determined that the relative angle θ is close to 0 °, the position of the target parking frame F1 is fixed and the composite image 33 is displayed. For example, when the absolute value of the relative angle θ with respect to the y-axis of the target parking frame F1 is within 5 °, it is determined that the relative angle θ is close to 0 °.

  As shown in FIGS. 9A and 9B, when the host vehicle C is turning toward the target parking frame F1, an initial drawing of the host vehicle image 35 in the upper center of the image display range R is drawn. The composite image 33 corresponding to the position within the predetermined distance from the vehicle position is displayed. As a result, the target parking frame F1 is not fixed within the image display range R, and the composite image 33 changes as the host vehicle C moves backward.

  As shown in FIG. 9C, when the host vehicle C is substantially parallel to the target parking frame F1, the image fixing control unit 18 fixes the composite image 33 in a state where the position of the target parking frame F1 at that time is fixed. Is displayed. In FIG. 9C, the target parking frame F <b> 1 is fixed at the approximate center in the image display range R.

  When the host vehicle C further travels straight back, the target parking frame F1 is displayed at the first fixed position (substantially the center in FIG. 9C), and is relative to the fixed target parking frame F1. The own vehicle image 35 moves. At this time, since the relative angle θ of the target parking frame F1 with respect to the host vehicle C is “0 °”, rotation conversion is not performed.

Therefore, according to the second embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(1) In the second embodiment, when the target parking frame F1 is parallel to the host vehicle C, the target parking frame F1 is fixed and drawn at the lower center position. For this reason, since the image which the own vehicle C retreats with respect to the target parking frame F1 can be displayed, the parking assistance screen 40 without a sense of incongruity can be displayed at a precise timing.

In addition, you may change this embodiment as follows.
In the first embodiment, when the target parking frame F1 is included in the image display range R, the composite image 33 is displayed in a state where the vehicle image 35 is arranged at the lower center of the image display range R. Other positions may be used. For example, the center of the image display range R may be used.

  In the above embodiment, the composite image 33 overlooking the vehicle periphery is displayed on the parking assistance screen 40. However, a monitor image based on the image data G may be displayed as the parking assistance screen 40. At this time, since a part of the vehicle body is usually photographed in the image data G, this vehicle body image is set as the own vehicle image. Then, a composite image in which the display position of the target parking frame F1 is fixed may be displayed at a timing such as when at least a part of the target parking frame F1 is included in the shooting range of the camera 25.

In the above embodiment, the vehicle image 35 is drawn on a photographic image based on the image data G, but the vehicle image 35 may be drawn on an image based on a prestored parking lot map.
In the above embodiment, the past image 31 based on the overhead view data G1 may be omitted from the composite image 33.

  In the above embodiment, when the target parking frame F1 is included in the image display range R, the composite image 33 is fixed with the target parking frame F1 being parallel to the host vehicle C as a trigger. . In addition to this, when any parking frame F is included in the image display range R instead of the preset target parking frame F1, any parking frame F is parallel to the host vehicle C. It may be a trigger.

The block diagram of the parking assistance system of this embodiment. The screen figure of a synthesized image. Explanatory drawing of the calculation process of the position of a target parking frame, and a relative angle. Explanatory drawing of the parallel movement and rotation movement of synthetic | combination data. The flowchart of the process sequence of this embodiment. The flowchart of a camera image taking-in process. The flowchart of an image display range fixing process. (A) And (b) is a screen figure of the parking assistance screen before fixing, (c) and (d) is after fixing. It is a parking assistance screen of 2nd Embodiment, Comprising: (a) And (b) is a screen figure before fixation, (c) And (d) is after fixation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Parking assistance system, 2 ... Parking assistance unit as parking assistance apparatus, 5 ... Display as display means, 13 ... Overhead conversion part as surrounding image drawing means, 15 ... As surrounding image drawing means, own vehicle image drawing means Image synthesizing unit, 18 ... Image fixing control unit as drawing switching means, 33 ... Synthetic image as vehicle peripheral image, 35 ... Own vehicle image, C ... vehicle, F ... parking frame, R ... image display range.

Claims (5)

In the parking support method for displaying the image around the vehicle on the display means,
A vehicle periphery image is output to the display means, and the vehicle image is drawn at a position corresponding to the current position of the vehicle among the vehicle periphery images,
When the vehicle approaches the parking frame, the parking frame is fixed at a predetermined position, the vehicle surrounding image is drawn, and the host vehicle image is moved on the vehicle surrounding image as the vehicle moves backward. A parking assistance method characterized by the above. In the parking assist device that displays the image around the vehicle on the display means,
Peripheral image drawing means for outputting a vehicle peripheral image to the display means;
A vehicle image drawing means for drawing a vehicle image at a position corresponding to the current position of the vehicle among the vehicle peripheral images;
When the vehicle approaches the parking frame, the parking frame is fixed at a predetermined position to draw the vehicle surrounding image, and the vehicle image is moved on the vehicle surrounding image as the vehicle moves backward A parking assistance device comprising switching means. In the parking assistance device according to claim 2,
The drawing switching means includes
The parking assistance device, wherein when the entire area of the parking frame is included in the image display range of the display means, the vehicle periphery image drawn with the parking frame fixed at a predetermined position is drawn. In the parking assistance device according to claim 2 or 3,
The drawing switching means includes
When the parking frame displayed in the vehicle periphery image is parallel to the vehicle, the parking region is drawn with the parking frame fixed and drawn at a predetermined position. Support device. In the parking assistance device according to any one of claims 2 to 4,
The said drawing switching means displays the said vehicle periphery image in the state which made the display position of the said parking frame the lower center of the image display range, The parking assistance apparatus characterized by the above-mentioned.

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