JP4561470B2 - Parking assistance device - Google Patents

Description

  The present invention relates to a parking assistance device.

Conventionally, as a device for assisting driving operation when parking a car, a parking support that images a peripheral field of view with a camera attached to the rear end of the vehicle and displays the imaged data on a display arranged in the vehicle interior. The device is known. In this type of parking assistance device, by performing image processing using past image data and synthesizing a pseudo image in the area that becomes the blind spot of the current image, and displaying the area that becomes the blind spot of the driver on the display, A parking assistance device has been proposed that reduces the driver's anxiety during parking (Patent Document 1).
JP 2003-244688 A

  However, the parking assist apparatus described above enters the assist mode when the vehicle operates the shift lever in reverse (reverse) and the vehicle speed becomes equal to or lower than a preset vehicle speed, and present image data and past image data. The area that becomes the blind spot of the driver is displayed on the display.

  However, if the display / non-display of the pseudo image based on the past image data is switched by one set vehicle speed, the pseudo image is suddenly displayed, or conversely, the pseudo image is suddenly disappeared. Accordingly, the driver suddenly changes the displayed range greatly, making it difficult to accurately grasp the driving situation.

  The present invention has been made to solve the above problems, and its purpose is to determine the display range of the current image and the display range of the past image displayed on the display means according to the vehicle speed, and Another object of the present invention is to provide a parking assistance device that can accurately grasp the driving situation.

According to the first aspect of the present invention, there is provided imaging data acquisition means for acquiring an image in the traveling direction of a vehicle as current image data, vehicle speed detection means for detecting the vehicle speed of the vehicle , and current image data acquired by the imaging data acquisition means . A past image data generating means for adding the position information of the vehicle and storing it in the storage means as past image data, a part of the current image based on the current image data newly acquired by the imaging data acquiring means , Display means for displaying a composite screen obtained by combining a part of the past image based on the past image data previously stored in the storage means, and the current image is displayed on the composite screen according to the vehicle speed. Display control means for changing a ratio between a display range and a display range in which the past image is displayed on the composite screen is provided.

According to a second aspect of the invention, in the parking assist apparatus according to claim 1, wherein the display control unit, the vehicle speed is indeed small, corrects the ratio as Viewing scope of the past image in the combined screen becomes larger To do .

According to a third aspect of the present invention, in the parking assist device according to the first or second aspect , the past image data generation means adds the current image data at that time each time the vehicle moves a predetermined distance in the traveling direction. Past image data is generated by adding the current imaged position at that time as vehicle position information and stored in the storage means.

A fourth aspect of the present invention, in the parking assist apparatus according to claim 1, wherein the display control unit, a past image based on the past image data, the current image based the current image data after viewpoint conversion so that images viewed from the imaging viewpoint, changing the ratio.

A fifth aspect of the present invention, in the parking assist apparatus according to any one of claims 1 to 4, wherein the imaging data acquiring unit, a rear camera that captures an rear image of the vehicle, the vehicle moves backward The current image is acquired as the current image data.

According to the present invention, the display control means, since it is possible to determine the display range of the current image based on the current image data according to the vehicle speed, and a display range of the past image based on the past image data, For example, the ratio of the display range of the past image and the display range of the current image can be changed and displayed relative to the vehicle speed at that time. Accordingly, the driver can accurately grasp the driving situation accurately without suddenly changing the displayed range suddenly.

According to invention of Claim 2 , the ratio of the display range with respect to the present image of the past image displayed on a display means becomes large, so that vehicle speed becomes slow. Accordingly, the driver can accurately grasp the range where the blind spot is accurately obtained.

According to the invention of claim 3 , since the vehicle position information is attached to the past image data, the current image data and a part of the past image data are respectively extracted, and continuous synthesis is performed using the extracted image data. Images can be created.

According to the invention of claim 4, both turned image viewed from the same imaging perspective from the current image and the past image, the composite image is the current image and the past image is displayed with a seamlessly continuous.
According to the fifth aspect of the invention, when the vehicle is parked in the target parking area by retreating, it is possible to confirm the lower position of the invisible vehicle.

  Hereinafter, an embodiment in which the parking support device of the present invention is embodied in a navigation device that is mounted on an automobile and performs route guidance will be described with reference to FIGS. FIG. 1 is a block diagram illustrating the configuration of the navigation device 1.

  As shown in FIG. 1, the navigation device 1 includes a control device 2 as a control means. The control device 2 includes a control unit 3 that performs main control, a RAM 4 as an image data storage unit, and a ROM 5. The control unit 3 performs various processes according to various programs such as a route guidance program, an image data storage program, a composite data output program, and a parking assistance program stored in the ROM 5. The control unit 3 constitutes vehicle speed detection means, past image data generation means, and display control means described in the claims.

  The ROM 5 stores contour drawing data 5a. The contour drawing data 5 a is data for displaying the contour of the vehicle C on the display 12. In the present embodiment, the contour drawing data 5a is the rear wheel Ca of the vehicle C (see FIG. 3), and the contour T (see FIGS. 5 and 6) of the rear wheel Ca is drawn.

  In addition, the control device 2 includes a GPS receiver 6 and a vehicle position detector 7. The GPS receiver 6 receives radio waves from GPS satellites. Based on the detection data received from the GPS receiving unit 6, the own vehicle position detection unit 7 periodically calculates positioning data such as latitude, longitude, altitude indicating the absolute position of the own vehicle position. At this time, as shown in FIG. 3, the vehicle position detection unit 7 calculates the center point (vehicle position) Cp of the axle Cb of the rear wheel Ca of the vehicle C as a coordinate point on the road surface coordinate system. And while acquiring positioning data from GPS receiving part 6 sequentially, the own vehicle position by autonomous navigation is corrected and the own vehicle position is determined. The road surface coordinate system is a coordinate system for indicating the position of the vehicle C on the road surface.

Furthermore, the control device 2 includes a sensor interface (I / F unit 8). The control unit 3 receives the vehicle speed signal (pulse signal) and the travel distance signal (pulse signal) of the vehicle C from the vehicle speed sensor 20 and the travel distance sensor 21 disposed in the vehicle C via the I / F unit 8. get. The control unit 3 calculates the vehicle speed Vn as the current vehicle state based on the vehicle speed signal, and calculates the current travel distance DM based on the travel distance signal. At this time, the control unit 3 stores the vehicle speed Vn and the movement distance DM, which are calculated from time to time, in the RAM 4. Therefore, the RAM 4 has a storage area for that purpose.

  The control device 2 includes a map data storage unit 9. The map data storage unit 9 stores route data 9a and map drawing data 9b as map data. The route data 9a stores node data indicating nodes indicating intersections and turning points of roads, link data indicating links connecting the nodes, and the like. The control unit 3 performs route guidance processing to a destination. When performing the above, the route is searched according to the route data 9a and the route guidance program stored in the ROM 5. In addition, the control unit 3 collates the coordinates of the own vehicle position calculated as described above, the travel locus, and the route data 9a, and positions the coordinates of the own vehicle position on an appropriate road. Is further corrected. The map drawing data 9b is data for displaying a map from a wide range to a narrow range, and is associated with the route data 9a.

  In addition, the control device 2 includes an imaging data acquisition unit 10. The imaging data acquisition unit 10 periodically acquires image data from the rear camera 22 as imaging means provided in the vehicle C. The image data is digital data that has been analog / digital converted by the rear camera 22, and the imaging data acquisition unit 10 transmits it to the control unit 3 as image data Dn that can be subjected to image processing such as various corrections and synthesis. The control unit 3 outputs the acquired image data (current image data) Dn to the image processing unit 11 for causing the display 12 to display the rear image (current image Gn) at the current position.

  Further, every time the vehicle C moves a predetermined distance (500 mm in the present embodiment) while acquiring the current image data Dn at that time, the control unit 3 obtains the current image data Dn at that time at that time. The past image data Do is temporarily stored in the RAM 4 in association with the position.

  As shown in FIG. 2, the rear camera 22 is attached to the approximate center of the rear end of the vehicle C, such as a back door of the vehicle C, with the optical axis A facing downward. The rear camera 22 includes an optical mechanism including a wide-angle lens, a mirror, and the like, and a CCD image pickup device (none of which is shown). The wide-angle lens has a rear visual field of 140 degrees on the left and right, for example, and the rear camera 22 has an imaging range S (see FIG. 3) of about 8 m rearward including the rear end of the vehicle C with a depression angle F1 of 102 degrees, for example. Imaging is possible.

  Furthermore, as shown in FIG. 1, the control device 2 is connected to a steering sensor 23 and a shift sensor 24 provided in the vehicle C via the I / F unit 8. The control unit 3 acquires a steering angle detection signal and a shift position signal from the steering sensor 23 and the shift sensor 24. And the control part 3 judges whether the shift position of a transmission is a reverse state based on a shift position signal.

  When the shift position is reverse and the rear image of the vehicle C (current image Gn based on the current image data Dn) is simply displayed (hereinafter referred to as rear display mode), the control unit 3 and the like are stored in the ROM 5. Based on the steering angle detection signal, the current screen 33 shown in FIG. On the current screen 33, the background of the vehicle C is displayed, and the predicted trajectory line 31 and the vehicle width extension line 32 are drawn on the background in a known manner. The expected trajectory line 31 indicates a travel trajectory according to the steering angle and the vehicle width of the vehicle C. The vehicle width extension line 32 is an index obtained by extending the vehicle width of the vehicle C rearward. Therefore, the driver steers the vehicle according to the amount of deviation between the predicted trajectory line 31 and the vehicle width extension line 32 when parking.

When the shift position is reverse and images of the rear and lower sides of the vehicle C (images based on the current image data Dn and the past image data Do) are displayed (hereinafter referred to as see-through mode), the control unit 3 or the like The composite screen F shown in FIG. 5 or 6 is displayed on the display 12 in accordance with the parking assistance program stored in the ROM 5. On the composite screen F, the current image G
This is a screen in which a part Gna of n and a part Goa of the past image Go are combined. The current image Gn is generated based on the current image data Dn acquired by the control unit 3 at that time. The past image Go is generated based on the past image data Do stored in the RAM 4.

  That is, as shown in FIG. 7, the composite screen F uses a part Dna of the current image data Dn and a part Goa of the past image data Do, and a part Gna of the current image Gn is displayed on the upper side of the composite screen F. It is generated so that a part Goa of the past image Go is located on the lower side.

  At this time, the past image Go displayed on the composite screen F is obtained by converting the past image data Do to the current camera viewpoint (imaging viewpoint) IP (see FIG. 2) of the rear camera 22, and from the camera viewpoint IP to the vehicle. It is an image obtained when C is seen through. In other words, the viewpoints are matched so that the display of the part Gna of the upper current image Gn and the part Goa of the lower past image Go are made continuous so that the driver can easily recognize them.

  In the present embodiment, the ratio of the display range in which the current image Gn is displayed and the display range in which the past image Go is displayed on the composite screen F is changed according to the vehicle speed Vn at that time.

  More specifically, when the vehicle speed Vn is 15 km / h or higher, only the current image Gn based on the current image data Dn is displayed. Further, when the vehicle speed Vn is less than 15 km / h to 10 km / h or more, as shown in FIG. 5, a part Gna of the current image Gn up to 3000 mm backward from the rear end of the vehicle C and forward from the rear end of the vehicle C A composite screen F including a part Goa of the past image Go up to 500 mm is displayed.

Further, when the vehicle speed Vn is less than 10 km / h to 5 km / h or more, a part Gna of the current image Gn up to 2000 mm from the rear end of the vehicle C to the rear and a forward direction from the rear end of the vehicle C to 100 mm.
A composite screen F including a part Goa of the past image Go up to 0 mm is displayed. Furthermore, when the vehicle speed Vn is less than 5 km / h to 0 km / h or more, as shown in FIG. 6, a part Gna of the current image Gn from the rear end of the vehicle C to 1500 mm rearward and the front from the rear end of the vehicle C A composite screen F including a part Goa of the past image Go up to 1500 mm is displayed.

  In the display based on the see-through mode, as shown in FIGS. 5 and 6, the display 12 becomes a display of the composite screen F between the current image Gn and the past image Go, and the vehicle C can be operated more. In order to drive carefully, a message M indicating that driving is performed while directly checking the periphery of the vehicle is displayed. In this embodiment, data for displaying the message M is stored in advance in the ROM 5 together with the contour drawing data 5a.

As shown in FIGS. 5 and 6, the contour T of the rear wheel Ca at the current vehicle position is superimposed and displayed on a part Goa of the past image Go.
Further, the navigation device 1 includes the display 12 as the display means described above. The display 12 is a touch panel, and when the shift position of the transmission of the vehicle C is reversed, the current screen 33 based on the current image data Dn obtained by imaging the rear of the vehicle C, the current image data Dn, and the past image data Do. A composite screen F based on is displayed. Further, when the shift position of the transmission is not reverse, the display 12 outputs the map drawing data 9b transmitted from the control unit 3 and the map screen 12a around the vehicle position (see FIG. 1). Is displayed along with the vehicle position mark.

The input signal acquisition unit 13 included in the control device 2 acquires an input signal input by operating the touch panel of the display 12 and an input signal input by pressing the operation button 14 provided on the navigation device 1. To the control unit 3. Operation button 14
Is provided with a display mode switching button 14a. The display mode switching button 14a is a button for selecting either the rear display mode or the see-through mode. Therefore, by operating the display mode switching button 14a, the control device 2 (control unit 3) is set to either the rear display mode or the see-through mode.

The navigation device 1 includes a speaker 15. The speaker 15 outputs various guidance voices and guidance sounds based on the voice output signal transmitted from the control unit 3.
Further, the control device 2 includes an image processing unit 11. The image processing unit 11 synthesizes the current image data Dn and the past image data Do in accordance with the image synthesis command received from the control unit 3 that has entered the see-through mode.

  The image processing unit 11 synthesizes a part Dna of the current image data Dn and a part Doa of the past image data Do according to the vehicle speed Vn at that time. That is, as schematically shown in FIG. 7, the image processing unit 11 includes a part Dna (shown by hatching) of the image based on the current image data Dn and a part Doa (shown by hatching) of the image based on the past image data Do. ) Are superimposed to generate image composition data DA for displaying one continuous image (composition screen F) on the display 12. At this time, as described above, the image processing unit 11 has a part of the image Go based on the past image data Do (past image Goa) below a part of the image Gn based on the current image data Dn (current image Gna). Are generated and one continuous image (composite screen F) is generated.

More specifically, the image processing unit 11 displays only the current image Gn based on the current image data Dn when the vehicle speed Vn is 15 km / h or higher.
Further, when the vehicle speed Vn is less than 15 km / h to 10 km / h or more, the image processing unit 11 extracts from the current image data Dn the current image data Dna of a portion in which up to 3000 mm is captured rearward from the rear end of the vehicle C. To do. On the other hand, the image processing unit 11 reads past image data Do from the RAM 4. Then, the past image data Do is converted into the viewpoint image data Do obtained when the viewpoint C is converted to the camera viewpoint IP of the rear camera 22 at the current position and the vehicle C is seen through from the camera viewpoint IP ( Change viewpoint). Then, the image processing unit 11 extracts the past image data Doa of a portion in which a distance of 500 mm is imaged forward from the rear end of the vehicle C from the viewpoint-converted past image data Do. The image processing unit 11 generates a composite screen F by combining the extracted current image Gna of the current image data Dna and the past image Goa of the past image data Doa.

Furthermore, when the vehicle speed Vn is less than 10 km / h to 5 km / h or more, the image processing unit 11 extracts from the current image data Dn the current image data Dna of the portion where the image is captured from the rear end of the vehicle C to 2000 mm backward. To do. On the other hand, the image processing unit 11 reads the past image data Do from the RAM 4 and obtains the past image data Do converted to the camera viewpoint IP at the current position as described above. The image processing unit 11 then captures past image data D from the viewpoint-converted past image data Do from the rear end of the vehicle C up to 1000 mm forward.
oa extract. The image processing unit 11 generates a composite screen F by combining the extracted current image Gna of the current image data Dna and the past image Goa of the past image data Doa.

  Furthermore, when the vehicle speed Vn is less than 5 km / h to 0 km / h or more, the image processing unit 11 obtains the current image data Dna of the portion of the current image data Dn that is captured from the rear end of the vehicle C to 1500 mm backward. Extract. On the other hand, the image processing unit 11 reads the past image data Do from the RAM 4 and obtains the past image data Do converted to the camera viewpoint IP at the current position as described above. Then, the image processing unit 11 extracts the past image data Doa of the portion in which up to 1500 mm is imaged from the rear end of the vehicle C from the viewpoint-converted past image data Do. The image processing unit 11 generates a composite screen F by combining the extracted current image Gna of the current image data Dna and the past image Goa of the past image data Doa.

  At this time, the image processing unit 11 reads out the contour drawing data 5a from the ROM 5, and superimposes the contour T of the rear wheel Ca at the current vehicle position on the past image Goa as shown in FIGS. And display it pseudo. Similarly, the image processing unit 11 reads message data from the ROM 5 and displays a message M.

  Next, the operation of the navigation device 1 according to the present embodiment will be described with reference to flowcharts showing processing procedures of the control device 2 shown in FIGS. For convenience of explanation, a case will be described in which the vehicle C parks back (retreats) from the position shown in FIG. 10 to the parking area R defined by the white line 100 of the parking lot.

  Now, when the vehicle C at the position shown in FIG. 10 switches the shift lever to reverse (back) to park in the target parking area R, the control unit 3 inputs a shift position signal from the shift sensor 24, It is determined whether or not the shift position of the transmission is in a reverse state based on the shift position signal (step S1). At this time, since the shift lever is switched to reverse (back), the control unit 3 determines that the shift position of the transmission is in the reverse state (YES in step S1), and proceeds to step S2. When the shift lever is other than reverse, the control unit 3 performs other processing (step 3) and returns to step S1.

  When the shift position is in the reverse state, the control unit 3 drives the rear camera 22 via the imaging data acquisition unit 10 and starts acquiring image data (current image data Dn) of the rear image captured by the rear camera 22 ( Step S2). Subsequently, the control unit 3 determines whether it is the see-through mode or the rear display mode (step S4). The control unit 3 makes a determination based on a mode flag stored in a predetermined work memory area of the RAM 4 based on whether or not the display mode switching button 14a is operated.

  When the see-through mode is set in advance by the display mode switching button 14a, the control unit 3 moves to step S5, sets the content of the movement distance DM stored in the work storage area in the RAM 4 to zero, Thereafter, the measurement of the travel distance DM is started based on the travel distance signal from the travel distance sensor 21. Subsequently, the control unit 3 acquires the current image data Dn at that time and the information on the vehicle position at that time (step S6). The current image data Dn is acquired from the imaging data acquisition unit 10. The information on the vehicle position is acquired by the control unit 3 based on the detection signal obtained from the vehicle position detection unit 7 or the like. Next, the control unit 3 adds the acquired current image data Dn to the current vehicle position information and stores it as past image data Do in the past image storage area of the RAM 4 (step S7).

  When the past image data Do is stored in the RAM 4, the control unit 3 cooperates with the image processing unit 11 until the imaging data acquisition unit 10 is operated until the vehicle C moves backward by 500 mm or an end trigger signal is generated. The current image Gn generated based on the current image data Dn captured by the rear camera 22 is displayed on the display 12 (steps S8, S9, S10). Whether or not the vehicle C has moved back by 500 mm is determined based on the content of the travel distance DM measured by the control unit 3 based on the travel distance signal from the travel distance sensor 21 and stored in the RAM 4. The end trigger signal is generated when the shift sensor 24 detects that the shift position is switched to a shift position other than reverse or when the driver operates the display mode switching button 14a to stop the see-through mode.

Eventually, when the vehicle C moves backward by 500 mm (YES in step S9), the control unit 3 sets the content of the moving distance DM in the RAM 4 to zero and then starts measuring the moving distance DM again (step S11). Next, the control unit 3 acquires the current image data Dn at that time, information on the current vehicle position at that time, and the vehicle speed Vn at that time, and temporarily stores them in the work storage area of the RAM 4 (step S12). Subsequently, the control unit 3 reads the past image data Do previously stored in the past image storage area of the RAM 4 and temporarily stores it in the work storage area of the RAM 4 (step S13). Next, the control unit 3 creates a new past image created by adding the previous past image data Do stored in the past image storage area of the RAM 4 to the newly acquired current image data Dn with the information of the vehicle position at that time. The image data Do is updated (step S14).

  When the past image data Do is updated, the control unit 3 determines whether or not the vehicle speed Vn acquired in step S12 is less than 15 km / h (step S15). When the vehicle speed Vn is 15 km / h or more (NO in step S15), the control unit 3 performs image processing in the same manner as in steps S8 to S10 until the vehicle C moves backward by 500 mm or until an end trigger signal is generated. In cooperation with the unit 11, the current image Gn generated based on the current image data Dn captured by the rear camera 22 via the imaging data acquisition unit 10 is displayed on the display 12 (steps S16, S17, S18).

  On the other hand, when the vehicle speed Vn is less than 15 km / h (YES in step S15), the control unit 3 displays the current image Gn based on the current image data Dn when displayed on the display 12 in cooperation with the image processing unit 11. The display range of the past image Go based on the range and the past image data Do, that is, the display ratio is set based on the vehicle speed Vn acquired in step S12 (step S16).

  More specifically, when the vehicle speed Vn is less than 15 km / h to 10 km / h or more, the current image Gn is an image Gna up to 3000 mm backward from the rear end of the vehicle C, and the past image Go is up to 500 mm forward from the rear end of the vehicle C. Set so that the image Goa is displayed. When the vehicle speed Vn is less than 10 km / h to 5 km / h or more, the current image Gn is an image Gna up to 2000 mm backward from the rear end of the vehicle C, and the past image data Do is an image up to 1000 mm forward from the rear end of the vehicle C. Set so that Goa is displayed. Further, when the vehicle speed Vn is less than 5 km / h to 0 km / h or more, the image processing unit 11 displays the current image Gn from the rear end of the vehicle C to the rear 1500 mm, and the past image Go from the rear end of the vehicle C to the front. It is set so that an image Goa up to 1500 mm is displayed.

  When the display range is set, the control unit 3 cooperates with the image processing unit 11 to execute image composition processing (step S20). More specifically, when the vehicle speed Vn is less than 15 km / h to 10 km / h or more, the current image data Dna of the portion where the image from the rear end of the vehicle C up to 3000 mm is imaged rearward is extracted from the current image data Dn. On the other hand, for the past image data Do, the viewpoint is converted to the camera viewpoint IP of the rear camera 22 at the current position, and from the past image data Do that has been converted to the viewpoint, the portion from which the vehicle C is imaged up to 500 mm forward from the rear end. Past image data Doa is extracted. Then, the extracted current image data Dna and past image data Doa are synthesized.

Further, when the vehicle speed Vn is less than 10 km / h to 5 km / h or more, the current image data Dna of the portion of the current image data Dn that is imaged up to 2000 mm backward from the rear end of the vehicle C is extracted. On the other hand, in the same manner as described above, the past image data Doa of the portion in which up to 1000 mm is imaged forward from the rear end of the vehicle C is extracted from the past image data Do converted into the camera viewpoint IP at the current position. Then, the extracted current image data Dna and past image data Doa are synthesized.

Further, when the vehicle speed Vn is less than 5 km / h to 0 km / h or more, the current image data Dna of the portion of the current image data Dn that is imaged up to 1500 mm backward from the rear end of the vehicle C is extracted. On the other hand, in the same manner as described above, the past image data Doa of the portion in which up to 1500 mm is imaged forward from the rear end of the vehicle C is extracted from the past image data Do converted into the camera viewpoint IP at the current position. Then, the extracted current image data Dna and past image data Doa are synthesized.

  When the current image data Dna extracted according to the vehicle speed Vn and the past image data Doa are combined, the control unit 3 cooperates with the image processing unit 11 to present the current image Gna and the past image data of the current image data Dna. A composite screen F formed by combining the past images Goa of Doa is displayed on the display 12 (step S21). Until the vehicle C moves back 500 mm or until the end trigger signal is generated, the control unit 3 cooperates with the image processing unit 11 in the same manner as in the steps S16 to S18, and the imaging data acquisition unit 10 The composite screen F generated based on the current image data Dna and the past image data Doa captured by the rear camera 22 is displayed on the display 12 (steps S21, S22, S23).

  In step S18 or step S22, when the vehicle C moves backward to 500 mm, the control unit 3 moves to step S11, sets the content of the moving distance DM in the RAM 4 to zero, and then repeats the above-described processing again. Therefore, each time the vehicle C moves backward by 500 mm, the past image data Do is updated, and the composite screen F in which the display ratio of the current image Gna and the past image Goa is set according to the vehicle speed Vn at that time is displayed on the display 12. fall back. That is, the past image Goa is combined with the current image Gna on the display 12 and the road surface below the vehicle C and from the rear end of the vehicle C to the front side of the vehicle C is displayed. Therefore, the driver can visually recognize the road surface on the front side of the vehicle C from the rear end of the vehicle C, which cannot be captured by the rear camera 22 at the current position, in relation to the vehicle C.

  Further, the ratio of the display range of the past image Goa displayed on the display 12 to the current image Gna increases as the vehicle speed Vn decreases. Accordingly, the driver can grasp the driving situation accurately and accurately since the displayed range does not change suddenly.

  In addition, when the driver approaches the stop point closer to the blind spot such as a car stop, for example, when the vehicle C is slowly moved backward, the display ratio of the part that becomes a blind spot such as a car stop increases. Thus, the lower part of the vehicle C that becomes a blind spot can be grasped more reliably, and an appropriate driving operation can be performed.

  Further, when the vehicle speed Vn is 15 km / h or higher, the current image Gn (current screen 33) is displayed on the display 12 instead of the composite screen F. Therefore, when reversing while confirming a rear position that is not necessary to confirm the road surface condition that becomes a blind spot below the vehicle C, only the current image Gn captured by the rear camera 22 at that time is displayed. Without switching from the see-through mode to the rear display mode, the driver can visually recognize a wide range of rear positions without being bothered by the display of the past image Go and can perform an appropriate driving operation.

  When an end trigger signal is generated in step S10, step S18, or step S23, the control unit 3 ends the display of the composite screen F or the current image on the display 12 (step S24), and the movement stored in the RAM 4 The distance DM, past image data Do, etc. are deleted, and the vehicle support processing operation is terminated (step S25).

In step S4, when the rear display mode is determined, the control unit 3 cooperates with the image processing unit 11 until the end trigger signal is generated, and the rear camera 22 is operated via the imaging data acquisition unit 10. A current image Gn generated based on the captured current image data Dn is displayed on the display 12 (steps S26, S27, S4). When the end trigger signal is generated (YES in step S27), the control unit 3 moves to step S24 and step S25, ends the display of the current image, and erases the moving distance DM and the like stored in the RAM 4. The vehicle support processing operation is terminated (step S25).

According to this embodiment, the following effects can be obtained.
(1) In the present embodiment, the ratio of the display range of the past image Goa displayed on the display 12 to the current image Gna is increased relative to the vehicle speed Vn, that is, as the vehicle speed Vn is decreased. Accordingly, the driver can grasp the driving situation accurately and accurately since the displayed range does not change suddenly.

  In addition, the closer the driver is to the stop point, for example, when the vehicle C is slowly moved backward while paying attention to the part that becomes a blind spot such as a car stop, the display ratio of the part that becomes a blind spot such as a car stop increases. As a result, the driver can more reliably grasp the lower part of the vehicle C, which is a blind spot, and can perform an appropriate driving operation.

  (2) In the present embodiment, the contour T of the rear wheel Ca at the current vehicle position is superimposed on the past image Goa and displayed in a pseudo manner, so that the driver can use the rear wheel Ca and the white line 100 as blind spots. The positional relationship can be easily and reliably grasped, and an appropriate driving operation can be performed.

  (3) In this embodiment, when the vehicle speed Vn is 15 km / h or higher, the current image Gn (current screen 33) is displayed on the display 12 instead of the composite screen F. Therefore, when reversing while confirming a rear position that is not necessary to confirm the road surface condition that becomes a blind spot below the vehicle C, only the current image Gn captured by the rear camera 22 at that time is displayed. Without switching from the see-through mode to the rear display mode, the driver can visually recognize a wide range of rear positions without being bothered by the display of the past image Go and can perform an appropriate driving operation.

  (4) In this embodiment, since the ratio of the display range of the past image Goa and the current image Gna changes according to the vehicle speed Vn, the driver can also grasp the vehicle speed Vn at that time from the composite screen F.

  (5) In the present embodiment, as the past image Go, the past image data Do obtained by converting the viewpoint to the camera viewpoint IP at the current position is obtained. That is, the past image Go is an image viewed from the same imaging viewpoint as the current image Gn, and the composite screen F can display the current image Gna and the past image Goa with continuity without a sense of incongruity.

In addition, you may change the said embodiment as follows.
In the above embodiment, when the vehicle speed Vn changes step by step, the display ratio is determined for each step. Alternatively, the display ratio may be changed continuously for each vehicle speed Vn. In the above embodiment, the vehicle speed Vn for changing the display range may be changed as appropriate.

In the above embodiment, the vehicle position is the center point Cp of the rear axle, but may be a specific position of another vehicle C.
In the above embodiment, the moving distance DM for updating the past image data Do is set to 500 mm. However, the moving distance DM is set to a shorter distance (for example, 400 mm, 200 mm, 150 mm, 100 mm, etc.) or on the contrary to a longer distance. You may implement.

  In the above embodiment, the past image Go is an image whose viewpoint is converted to the camera viewpoint IP at the current position. However, the present invention is not limited to this. For example, the past image Go may be a past image in which the viewpoint is not converted. In short, the display method of the current image and the past image may be any method as long as the ratio of the display range of the current image and the past image in the composite screen is changed according to the vehicle speed Vn.

In the above-described embodiment, the rear display mode and the see-through mode can be selected. However, only the see-through mode may be used.
In the above-described embodiment, the contour T of the rear wheel Ca is superimposed and displayed on the past image Goa. However, the present invention is not limited to this, and a vehicle width line or the like indicating the vehicle width of the vehicle C is displayed. May be. Further, a distance guide line indicating a distance from the rear end to a predetermined distance (for example, 50 cm) may be displayed on the current image Gna.

  In the above embodiment, the vehicle support device is used when the vehicle C travels backward (retreats). The rear camera 22 may be embodied in a vehicle support device that is attached not to the rear but to the front of the vehicle C and travels (forwards) toward the front. For example, when entering the parking area while moving forward, the closer to the parking area stop position (at this time, the vehicle speed Vn also falls correspondingly), the road surface below the front side of the vehicle that becomes a blind spot with a bonnet or the like is displayed. Therefore, the driver can visually recognize the road surface on the rear side of the vehicle C from the front end of the vehicle C in relation to the vehicle C. In other words, since the past image data Do generated by the front camera can be used to display the area below the vehicle body, it is possible to easily view an obstacle that is difficult to see in front of the vehicle C.

  -In above-mentioned embodiment, although vehicle speed Vn was materialized as a vehicle state, you may materialize the reach distance to a target parking position as a vehicle state. That is, the ratio of the display range of the past image to the current image may be increased as the reach distance from the current position of the vehicle C to the target parking position becomes shorter. In this case, the control unit 3 constitutes a reach distance detecting unit.

  More specifically, from the image captured by the rear camera 22 of the vehicle C, the control unit 3 recognizes an image from a parking frame, a wheel stopper, etc. as a target parking area (target parking area) R as shown in FIG. To do. Further, the control unit 3 calculates a distance (reach distance) from the current position to the target parking area R acquired by image recognition using a signal from the travel distance sensor 21. Then, the control unit 3 determines the display range of the current image Gna and the display range of the past image Goa according to the calculated reach distance.

  In addition, when calculating the reach distance to the target parking area R as the target parking position, the center point of the parking frame of the target parking area R may be set as the reference position for the distance calculation, or the vehicle C closest to the parking frame. A near end point may be used as a reference position for distance calculation. In this case, for example, the control unit 3 sets the arrival distance to the target parking area R when the target parking area R is recognized as the total distance L1, and the ratio of the arrival distance L2 to the parking area R at that time with respect to the total distance L1 Rx (= L2 / L1) is obtained. Then, the control unit 3 determines the display range of the current image Gna and the display range of the past image Goa according to the obtained ratio Rx.

  As a specific display, when the ratio Rx is 1 ≧ Rx> 0.5, only the current screen 33 shown in FIG. When the ratio Rx is 0.5 ≧ Rx> 0.2, the composite screen F shown in FIG. When the ratio Rx is 0.2 ≧ Rx, the composite screen F shown in FIG. 6 shown in the above embodiment is displayed on the display 12.

Further, the display range of the current image Gna and the display range of the past image Goa may be determined according to the reach distance L2 (remaining distance) to the target parking area R without using the ratio Rx. As a specific display in this case, when the reach distance L2 is L2 ≧ 5 m, only the current screen 33 shown in FIG. When the reach distance L2 is 5m ≧ L2> 2m, the composite screen F shown in FIG. When the reach distance L2 is 2m ≧ L2, the composite screen F shown in FIG.

  Thus, by determining the display range of the current image Gna and the display range of the past image Goa according to the calculated reach distance, the displayed range does not suddenly change greatly, and as the vehicle approaches the target parking area R. The display range of the past image Goa is enlarged, and the lower position of the vehicle C in the second half of parking can be confirmed widely.

  In this case, the target parking area R is set as the target parking position. However, the present invention is not limited to this. For example, the wheel stop may be recognized as an image and the wheel stop may be set as the target parking position.

  In the above embodiment, the parking assistance device is embodied as the navigation device 1 that performs route guidance, but may be a device that omits route guidance. In this case, the map data storage unit 9 is omitted.

The block diagram explaining the structure of the navigation apparatus of this embodiment. Explanatory drawing explaining the rear camera arrange | positioned at the vehicle. Explanatory drawing explaining the position of the vehicle at the time of performing the process of this embodiment. Explanatory drawing of the screen in back display mode. Explanatory drawing of the synthetic | combination screen in see-through mode. Explanatory drawing of the synthetic | combination screen in see-through mode. The schematic diagram for demonstrating the synthesis | combination of image data. The flowchart which shows the process sequence of this embodiment. The flowchart which shows the process sequence of this embodiment. The figure which shows the relationship between the vehicle and parking lot for demonstrating the process sequence of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus as parking assistance apparatus, 2 ... Control apparatus, 3 ... Vehicle state detection means, Vehicle speed detection means, Past image data generation means, Display control means, Control part which comprises reach distance detection means, 4 ... RAM, DESCRIPTION OF SYMBOLS 7 ... Own vehicle position detection part, 10 ... Imaging data acquisition part, 11 ... Image processing part which comprises display control means, 12 ... Display, 14a ... Display mode switching button, 20 ... Vehicle speed sensor, 21 ... Travel distance sensor, 22 ... rear camera, 24 ... shift sensor, 33 ... current screen, A ... optical axis, C ... vehicle, Gn, Gna ... current image, Go, Goa ... past image, DA ... image composite data, Dn, Dna ... current image data , Do, Doa ... past image data, F ... composite screen, F1 ... imaging range, R ... target parking area, IP ... camera viewpoint as imaging viewpoint.

Claims (5)

Imaging data acquisition means for acquiring an image of the traveling direction of the vehicle as current image data;
Vehicle speed detecting means for detecting the vehicle speed of the vehicle ;
Past image data generation means for storing the current image data acquired by the imaging data acquisition means in the storage means as past image data by adding the position information of the vehicle;
A composite screen in which a part of the current image based on the current image data newly acquired by the imaging data acquisition unit and a part of the past image based on the past image data previously stored in the storage unit are combined . Display means for displaying;
According to the vehicle speed , a display control means is provided for changing a ratio between a display range in which the current image is displayed on the composite screen and a display range in which the past image is displayed on the composite screen. Parking assistance device. In the parking assistance device according to claim 1 ,
Wherein the display control unit, the vehicle speed is indeed small, the parking assist apparatus characterized by changing the proportions as Viewing range increases the past image in the combined screen. In the parking assistance device according to claim 1 or 2 ,
Each time the vehicle moves a predetermined distance in the direction of travel, the past image data generating means adds the current position captured at that time as current vehicle data to the current image data at that time as past vehicle data. A parking assistance device generated and stored in the storage means. In the parking assistance device according to any one of claims 1 to 3 ,
Wherein the display control unit, and wherein the past image based on the past image data, wherein after currently viewpoint conversion so that images viewed from an imaging point of view of the current image based on image data, corrects the ratio Parking assistance device. In the parking assistance device according to any one of claims 1 to 4 ,
The parking assistance device according to claim 1, wherein the imaging data acquisition unit acquires an image when the vehicle moves backward as current image data from a rear camera that captures an image behind the vehicle.

Images