JP7455482B2 - vehicle support equipment - Google Patents

Description

The present invention relates to a vehicle support device that displays a predicted trajectory of a vehicle as a guide line on a rearward image captured by a camera when the vehicle is reversing.

Conventionally, guide lines generated based on the predicted trajectory of the vehicle are superimposed on the rear image displayed on the display device to guide steering operations so that the vehicle stays in the center of the parking slot. Parking assistance devices are known (for example, see Patent Document 1). In this parking assist device, by changing the steering angle (steering angle) and aligning the guide line with the white line of the parking frame, it is possible to perform a steering operation to park the vehicle within the parking frame.

Japanese Patent Application Publication No. 2008-49889

By the way, in the parking assist device disclosed in Patent Document 1 mentioned above, guide lines are drawn on the assumption that there is a certain relationship between the steering angle and the tire angle. However, in reality, even if the vehicle is of the same model, the above relationship may not be exactly the same depending on the vehicle grade, tire diameter, type of tires installed, camber angle, etc., and the position of the drawn guide line may vary. There was a problem that misalignment occurred.

The present invention was created in view of these points, and its purpose is to provide a vehicle support device that can accurately display a guide line when reversing on a rearward image.

In order to solve the above-mentioned problems, the vehicle support device of the present invention includes an imaging means for taking an image of the rear of the vehicle, a rear image drawing means for drawing a rear image taken by the imaging means, and a rear image drawing means for drawing an image of the rear image taken by the imaging means, and a vehicle support device that uses a steering angle of the steering of the vehicle. A guide line indicating a predicted trajectory of the vehicle when the vehicle is moving backward by calculating the tire angle of the vehicle corresponding to the steering angle detected by the steering angle detection means and the steering angle detected by the steering angle detection means based on a predetermined conversion rule. a guide line drawing means for specifying the position of the rudder and drawing a guide line; a display means for displaying the guide line drawn by the guide line drawing means superimposed on the rear image drawn by the rear image drawing means; A conversion rule correction means that compares the vehicle position after reversing the vehicle while keeping the angle constant with the vehicle position indicated by the guide line before reversing, and corrects the conversion rule based on the comparison result. We are prepared.

Compare the vehicle position when the steering angle is fixed and the vehicle is actually moved backwards with the vehicle position indicated by the guide line indicated in advance, and correct the conversion rule when calculating the guide line. This makes it possible to adjust the contents of the conversion rule for each vehicle, and it is possible to accurately display a guide line when reversing on the rear image.

Further, the above-mentioned conversion rule correcting means is capable of reversing the vehicle while keeping the steering angle constant, so that the first vehicle position where the parking frame and the vehicle are parallel, and the first vehicle position where the parking frame and the vehicle are parallel before reversing. It is desirable to correct the conversion rule by comparing the position of the vehicle with the second vehicle position indicated by the guide line. This makes it possible to easily correct the conversion rule because it is known how much the vehicle position should be shifted by changing the contents of the conversion rule.

Further, it is preferable that the above-mentioned conversion rule correction means instructs the user to operate the steering wheel so that the position of the guide line has a predetermined relationship with the parking frame. This allows even a user without specialized knowledge to easily set the steering angle required for conversion rule correction.

In addition, the above-mentioned conversion rule is a conversion table that shows the relationship between the steering angle and the tire angle of the vehicle, and this conversion table is corrected so that the deviation between the first vehicle position and the second vehicle position is reduced. It is desirable to do so. Thereby, by using this conversion table after correction, it becomes possible to draw the guide line at the correct position.

FIG. 1 is a diagram showing the configuration of a vehicle support device according to an embodiment. FIG. 3 is a diagram showing a specific example of a steering angle-tire angle table. It is a figure showing the positional relationship of the vehicle and parking frame corresponding to phase 1. 7 is a diagram illustrating a display example of a rear image corresponding to phase 1. FIG. It is a figure which shows the positional relationship of the vehicle and parking frame corresponding to phase 2. 7 is a diagram illustrating a display example of a rear image corresponding to phase 2. FIG. 3 is a flowchart showing an operation procedure corresponding to phase 1. 7 is a flowchart showing an operation procedure corresponding to phase 2. 7 is a flowchart showing an operation procedure corresponding to phase 3. It is a figure showing the relationship between tire angle and rotation radius R of a vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle support system according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a vehicle support device according to an embodiment. As shown in FIG. 1, the vehicle support device 100 of this embodiment includes a camera 110, an image storage section 112, a rear image drawing section 114, a parking frame recognition section 120, a steering angle detection section 130, a guide line drawing section 132, a conversion It includes a table storage section 134, a display processing section 140, a display device 142, and a calibration processing section 150.

The camera 110 is attached to a predetermined position at the rear of the vehicle, and photographs the rear of the vehicle through a fisheye lens or a wide-angle lens. The image (rear image) obtained by the camera 110 is stored in the image storage section 112. The rear image drawing unit 114 reads out the image stored in the image storage unit 112 and draws a rear image for display.

The parking frame recognition unit 120 identifies the parking frame included in the rear image stored in the image storage unit 112 by image recognition (the parking frame is usually a white line, but may include lines of other colors). .

The steering angle detection unit 130 detects the steering angle of a steering wheel 200 provided in the driver's seat of the vehicle. The guide line drawing unit 132 determines whether the vehicle is moving backward based on the steering angle detected by the steering angle detection unit 130 when the shift lever (not shown) of the vehicle is in the reverse position (vehicle backwards). A trajectory is predicted (calculated) and a guide line indicating this trajectory is drawn. This drawing is performed by estimating the tire angle of the own vehicle corresponding to the steering angle using a conversion rule corresponding to this vehicle, and calculating the trajectory of the vehicle moving backward using this tire angle.

The conversion table storage unit 134 stores conversion rules used in calculations by the guide line drawing unit 132. There is a one-to-one relationship between the steering angle and the tire angle, and this relationship is stored in the conversion table storage unit 134 as a steering angle-tire angle table.

FIG. 2 is a diagram showing a specific example of a steering angle-tire angle table. In the example shown in FIG. 2, the steering angle and tire angle are in direct proportion. Although the simplest example shows a direct proportional relationship, if the relationship between the steering angle and the tire angle is shown by a broken line, or if at least part of it includes a curved part, the relationship between the outer wheel and the inner wheel is The contents of the steering angle-tire angle table vary depending on the structure of the vehicle, such as cases where the steering angle has a different relationship with the steering angle.

The display processing section 140 displays the rear image drawn by the rear image drawing section 114 on the screen of the display device 142 when the vehicle is reversing. Further, when a guide line is drawn by the guide line drawing unit 132, the display processing unit 140 displays the guide line on the rear image on the screen of the display device 142.

The calibration processing unit 150 performs a predetermined calibration process to correct the steering angle-tire angle table stored in the conversion table storage unit 134. In an initial state (for example, immediately after a vehicle is manufactured or sold), a steering angle-tire angle table is prepared in advance for each vehicle type and stored in the conversion table storage section 134. However, even for vehicles of the same model, the relationship between steering angle and tire angle differs slightly depending on the vehicle grade, tire diameter, type of tires installed, camber angle, etc., so the initial steering angle - tire angle table If used as is, the trajectory of the vehicle corresponding to the steering angle cannot be calculated accurately, and the position of the guide line will shift. In other words, if such a steering angle-tire angle table is used, even if the steering wheel 200 is operated so that the guide line fits within the parking frame and the vehicle is actually backed up while maintaining the steering angle at that time, the vehicle will not move. A situation may occur where the vehicle falls out of the parking frame. The calibration processing unit 150 corrects the steering angle-tire angle table so that the differences between vehicles are reflected in this way.

The camera 110 mentioned above serves as an imaging means, the rear image drawing section 114 serves as a rear image drawing means, the steering angle detection section 130 serves as a steering angle detection means, the guide line drawing section 132 serves as a guide line drawing means, a display processing section 140, The display device 142 corresponds to display means, and the calibration processing section 150 corresponds to conversion rule correction means.

The vehicle support device 100 of this embodiment has such a configuration, and its operation will be explained next. The steering angle-tire angle correction operation in this embodiment can be considered in three phases (phases 1, 2, and 3) as shown below.

(Phase 1): This is the first stage of operation at the time when the vehicle is about to back up toward the parking slot. FIG. 3 is a diagram showing the positional relationship between vehicles and parking spaces corresponding to Phase 1. FIG. 4 is a diagram showing a display example of a rear image corresponding to phase 1.

(Phase 2): This is the second stage of operation at the time when the parking frame and the vehicle become parallel. FIG. 5 is a diagram showing the positional relationship between vehicles and parking spaces corresponding to phase 2. FIG. 6 is a diagram showing a display example of a rear image corresponding to phase 2.

(Phase 3): This is a third stage operation in which the steering angle-tire angle table is corrected based on the deviation between the vehicle position planned before reversing and the actual vehicle position after reversing.

FIG. 7 is a flowchart showing the operation procedure corresponding to phase 1. When the rear of the vehicle is imaged by the camera 110 (step 100), the parking frame recognition unit 120 recognizes (extracts) the parking frame included in the rear image captured and stored in the image storage unit 112 (step 102). .

Further, the steering angle detection section 130 detects the steering angle of the steering wheel 200 (step 104), and the guide line drawing section 132 detects the steering angle based on the steering angle-tire angle table stored in the conversion table storage section 134. The tire angle corresponding to the determined steering angle is estimated, and a guide line corresponding to this tire angle is drawn (step 106).

Next, the display processing unit 140 displays the guide line drawn in step 106 on the screen of the display device 142, superimposing the guide line drawn in step 106 on the rear image drawn in step 100 (step 108). FIG. 4 shows an example of the display in step 108. This display image includes a parking frame and an arcuate guide line extending from a vehicle located diagonally with respect to the parking frame.

Next, the calibration processing unit 150 determines whether the guide line is at an appropriate position with respect to the parking frame (step 110). Here, the "appropriate position" refers to a state where the distance between the tangent line and the parking frame is equal on the left and right sides in a portion where the tangent line of the left and right arcuate guide lines is parallel to the left and right parking frame. If it is not in the appropriate position, a negative determination is made, and the calibration processing unit 150 instructs the driver of the vehicle to operate (rotate) the steering wheel 200 to change the steering angle (step 112). . This instruction can be given by displaying characters or the like to that effect on the screen of the display device 142, or by outputting a voice to that effect from a speaker (not shown). When the steering wheel 200 is operated to change the steering angle, the process returns to step 104 and the operations after detecting the steering angle are performed.

Further, if the guide line is at an appropriate position with respect to the parking frame, an affirmative determination is made in step 110, and the series of operations corresponding to phase 1 ends.

FIG. 8 is a flowchart showing the operation procedure corresponding to phase 2. The calibration processing unit 150 fixes the steering angle of the steering wheel 200 in a state where an affirmative determination is made in step 110 in FIG. An instruction to move backward is given to the driver (step 200). This instruction can also be given by display on the screen of the display device 142 or by audio output, similar to the instruction at step 112 in FIG. When the driver moves the vehicle backward in response to this instruction, the calibration processing unit 150 determines whether the vehicle has reached a predetermined position (step 202). Here, the "predetermined position" is a position where the longitudinal direction of the vehicle and the orientation of the parking frame are parallel. If the predetermined position has not been reached, a negative determination is made and this determination is repeated. When the predetermined position is reached, an affirmative determination is made in step 202, and the series of operations corresponding to phase 2 is completed. Note that when a predetermined position is reached, the driver may be notified to that effect and stop the vehicle from reversing, but the driver himself or herself may be able to make that judgment while looking at the rear image and then stop the vehicle from reversing. It may also be stopped.

FIG. 9 is a flowchart showing the operation procedure corresponding to phase 3. In a state in which an affirmative determination is made in step 202 of FIG. 8 (a state in which the vehicle has reached a predetermined position), the parking frame recognition unit 120 recognizes the left and right parking frames included in the rear image (step 300). . Next, the calibration processing unit 150 detects the amount of deviation of the tire position of the vehicle with respect to the recognized left and right parking frames (step 302). If the vehicle is backed up along the accurately drawn guide line, the vehicle should be in the center of the parking slot, and the center line of the left and right parking slots should match the center line of the vehicle. . However, if the drawing position of the guide line is not accurate, the position of the vehicle within the parking frame will deviate from the center, and this amount of deviation will be detected as the amount of deviation of the tire position. The calibration processing unit 150 calculates the vehicle position within the parking frame indicated by the guide line before reversing (second vehicle position) and the vehicle position within the parking frame after actually reversing (first vehicle position). ) is detected as the amount of tire position shift described above.

Next, the calibration processing unit 150 corrects the steering angle-tire angle table stored in the conversion table storage unit 134 based on the detected tire position shift amount (step 304).

FIG. 10 is a diagram showing the relationship between the tire angle and the rotation radius R of the vehicle. The turning radius R shown in FIG. 10 is a function of the steering angle (tire angle) α of the outer wheel and the steering angle β (tire angle) of the inner wheel, and by substituting values for these α and β, a specific value can be obtained. can be calculated. Note that if the outer wheels and inner wheels have different tire angles depending on the steering angle of the steering wheel 200, different steering angle-tire angle tables are prepared for each of the outer wheels and the inner wheels. The tire position deviation occurs because the steering angle-tire angle table is incorrect, and the pre-calculated turning radius R of the vehicle differs from the actual turning radius. Therefore, if the contents of the steering angle-tire angle table (for example, the inclination in the example shown in Fig. 2) are corrected, even if the steering angle is the same, the corresponding tire angles (the steering angle α of the outer wheel and the steering angle α of the inner wheel) can be corrected. Since the angle β) is changed and the radius of rotation R is changed, it is possible to eliminate the amount of deviation in tire position.

In this way, the vehicle support device 100 of the present embodiment compares the vehicle position when the steering angle of the steering wheel 200 is fixed and the vehicle is actually moved backwards with the vehicle position indicated by the guide line indicated in advance. By correcting the conversion rule (steering angle - tire angle table) when calculating the guide line, it becomes possible to adjust the contents of the conversion rule for each vehicle, and the guide line when reversing is displayed on the rear image. Lines can be displayed accurately.

Further, the above-mentioned conversion rule correcting means is capable of reversing the vehicle while keeping the steering angle constant, so that the first vehicle position where the parking frame and the vehicle are parallel, and the first vehicle position where the parking frame and the vehicle are parallel before reversing. The conversion rule is corrected by comparing the position of the vehicle with the second vehicle position indicated by the guide line. This makes it possible to easily correct the conversion rule because it is known how much the vehicle position should be shifted by changing the contents of the conversion rule.

In addition, by instructing the user (driver) to operate the steering wheel 200 so that the position of the guide line has a predetermined relationship with the parking frame before reversing the vehicle, the steering wheel necessary for correction of the conversion rule can be Even a user without specialized knowledge can easily set the steering angle of 200 degrees.

As described above, according to the present invention, the vehicle position when the steering angle is fixed and the vehicle is actually moved backward is compared with the vehicle position indicated by the guide line indicated in advance, and the guide line is determined. By correcting the conversion rule used to calculate , it becomes possible to adjust the contents of the conversion rule for each vehicle, and it is possible to accurately display a guide line when reversing on the rear image.

100 vehicle support device 110 camera 112 image storage unit 114 rear image drawing unit 120 parking frame recognition unit 130 steering angle detection unit 132 guide line drawing unit 134 conversion table storage unit 140 display processing unit 142 display device 150 calibration processing unit 200 steering

Claims (4)

an imaging means for imaging the rear of the vehicle;
Rear image drawing means for drawing a rear image captured by the imaging means;
a steering angle detection means for detecting a steering angle of a vehicle steering;
By calculating the tire angle of the vehicle corresponding to the steering angle detected by the steering angle detection means based on a predetermined conversion rule, the position of the guide line indicating the predicted trajectory of the vehicle when the vehicle is reversing is specified and guided. a guide line drawing means for drawing a line;
Display means for superimposing and displaying the guide line drawn by the guide line drawing means on the rear image drawn by the rear image drawing means;
A conversion rule that compares the vehicle position after the vehicle is backed up while keeping the steering angle constant with the vehicle position indicated by the guide line before backing up, and corrects the conversion rule based on the comparison result. a correction means;
A vehicle support device comprising: The conversion rule correction means is configured to set a first vehicle position where the parking frame and the vehicle become parallel by reversing the vehicle while keeping the steering angle constant, and a first vehicle position where the parking frame and the vehicle become parallel before reversing. 2. The vehicle support system according to claim 1, wherein the conversion rule is corrected by comparing the position of the vehicle with a second vehicle position indicated by the guide line. The vehicle assistance device according to claim 2, characterized in that the conversion rule correction means instructs the user to operate the steering wheel so that the position of the guide line has a predetermined relationship with the parking space. The conversion rule is a conversion table that shows the relationship between the steering angle and the tire angle of the vehicle, and the conversion table is corrected so that the deviation between the first vehicle position and the second vehicle position is reduced. The vehicle support device according to claim 2 or 3, characterized in that:

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