JP2000078566A - Parking auxiliary device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking auxiliary device by which even a beginner conducts parking operation without care and the packing operation is properly assisted. SOLUTION: In the parking auxiliary device 1 where a camera 17 picks-up an image of a back side of a vehicle at the time of parking operation and a display device 13 provided in the vehicle displays a video from the camera as a backside image and displays a driving estimate orbit 20 changing with a state of a steering angle superimposingly on the backside image, the device assists the parking operation by displaying a fixed locus denoting a vehicle locus at a maximized steering angle superimposingly on the backside image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parking assist device for assisting parking of a vehicle, and more particularly, to capturing a rear image with a camera and displaying the rear image on a display (monitor display) in the vehicle. The present invention relates to a parking assist device that assists a driver in a parking operation during a parking operation.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of assisting a beginner who is unfamiliar with parking such as parallel parking or garage parking during a parking operation. For example, in JP-A-7-17328, a CCD camera and a distance sensor for measuring a distance are provided around the vehicle body,
The surroundings of the vehicle are detected, and a surrounding image of the surroundings of the vehicle is displayed in a bird's-eye view on a display provided inside the vehicle to provide the driver with the surrounding situation.

In Japanese Patent Application Laid-Open No. 59-201082, a steering angle is detected by a steering sensor, the steering angle is calculated and output by a simple display.
In the device disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, a distance to an obstacle (particularly, a car parked next to a parking space to be parked) is measured by a distance measuring sensor for detecting an object provided behind the vehicle, There is known a method of detecting a turning start position based on the maximum steering angle in accordance with the distance and notifying the driver of the turning start position.

[0004]

However, the above-described conventional method is based on the premise that obstacles around the vehicle are detected using various sensing techniques.
The system for the processing becomes complicated. In addition, the method of measuring and notifying the distance to a nearby obstacle by using a distance measurement sensor or the like can be used when there is no car parked next to the parking space or when a person or object suddenly jumps out. It is difficult and does not assist parking properly.

[0005] In order to solve such a problem, a parking assist device for assisting parking by a simple method and appropriately providing useful information to a driver at the time of parking operation has been proposed. It was proposed in Japanese Patent Application No. 10-141474. This device detects the rear of a vehicle (own vehicle) by a camera provided at the rear of the vehicle, and displays an image captured by the camera on a display in the vehicle as a rear image. The vehicle assists the driver in parking by displaying a predicted traveling trajectory that changes according to the steering angle (the steering angle or the actual steering angle) on the rear image.

[0006] However, such a device that displays the predicted travel trajectory on the rear image is advantageous in that it can provide useful information about the surroundings to the driver when the vehicle is parked in the back. Considering actual use, the following points make it difficult to understand the operation situation, and in particular, a beginner driver who has a short driving history needs some familiarization.

That is, (1) it is difficult to judge the appropriate position of the back start, (2) it is difficult to determine the starting position and the amount of turning of the steering wheel (steering),
(3) It is difficult to determine the timing of returning the steering wheel after entering the parking section, and (4) it is difficult to determine the final stop position in the parking section.

Accordingly, the present invention has been made in view of the above problems, and it is a technical object of the present invention to provide a parking assist device in which even a beginner can perform a parking operation with a sense of security and appropriately assist the parking operation. Make it an issue.

[0009]

The technical means taken to solve the above-mentioned problem is that a rear view of the vehicle is picked up by a camera at the time of parking operation, and an image from the camera is displayed as a rear image in the vehicle. In a parking assist device that displays on a vehicle and superimposes a predicted traveling trajectory that changes according to the state of the steering angle on the rear image, a fixed trajectory that indicates the vehicle trajectory when the steering angle is maximized is superimposed on the rear image. Displayed.

[0010] According to this, since the fixed trajectory indicating the vehicle trajectory when the steering angle is maximized is displayed so as to be superimposed on the rear image, the parking assist reference position can be determined without turning, and then the vehicle is driven. If the driver turns the steering so that the expected trajectory matches the fixed trajectory, the steering start position and the steering amount can be easily understood,
Even beginners can perform parking operations with peace of mind.

More specifically, the vehicle is backed up so that the fixed trajectory is in front of the center of the white line of the parking section on the far side on the rear screen (indicating one parking space in a parking lot or the like), A position that is approximately in contact with the vehicle is set as a parking assist reference position. When the parking assist reference position is reached, the steering wheel is steered so that the predicted running trajectory matches the fixed trajectory,
The driver backs up to a position approaching the parking section while holding the steering wheel at the steering angle that matches the predicted travel trajectory. When the vehicle is straight with respect to the parking section, return the steering angle to the straight-ahead state, and pay attention to the back of the display screen and visually, paying attention to the back, and stop at a position completely in parallel with the parking section. Thus, even a beginner can easily park.

In this case, if the fixed trajectory is a vehicle trajectory on the turning outer wheel side during the parking operation, the position of the turning outer wheel passes, and the turning outer wheel touches the white line of the parking section. It is possible to easily determine the reference position.

The fixed trajectory is such that if the fixed trajectory is displayed on both the right and left sides when the steering angle is in the vicinity of the neutral position, the trajectory through which the vehicle passes when the steering angle is turned to the right or left is obtained. In both cases of turning right or left from the straight-back state during the parking operation, the fixed trajectory can be easily adjusted to the white line of the parking section.

If the fixed trajectory is displayed only in the steering direction at the time of the parking operation, the fixed trajectory is displayed only in the steering direction. Therefore, the driver reads the intention of the parking stall in which direction. In addition, appropriate parking assistance can be performed while only necessary information is displayed on the screen.

If a caution area is further displayed on the own vehicle side of the screen on which the predicted traveling trajectory is displayed, a place where the vehicle is likely to collide during the parking operation is displayed as a caution area. If the area is given special attention, the collision of the vehicle is prevented and the safety is improved.

If the display area of the caution area is changed between the side closer to the vehicle and the side farther from the own vehicle, it is possible to more clearly display the area having a high risk of collision, thereby improving safety. improves.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram of the parking assist device 1. In this figure, a controller 16 for controlling the parking assist device 1 detects a CCD camera (hereinafter, referred to as a camera) 17 for photographing the rear of the vehicle and a steering angle (also referred to as a turning angle) of a steering wheel (steering) 21. Sensor 2, a shift lever reverse switch 3 for detecting a reverse (reverse) state of a transmission shift lever, a parking switch 4 for activating a parking assist function at the time of a parking operation, and wheels for detecting left and right wheel speeds of driven wheels. Signals from the speed sensors 5 and 6 are input, and the controller 16
Can display a rear image of the vehicle, a predicted travel locus 20 described later, and the like on the display 13. Also,
The apparatus 1 is provided with a voice synthesizing function. A voice synthesis circuit 7 outputs a voice synthesis output, and a speaker 8 outputs an output by voice synthesis to a driver.

In the controller 16, C for controlling
PU 11, a graphics drawing circuit 12 for drawing graphics on the display 13, a superimposing circuit 9 for superimposing a graphics signal and a rear image from the camera 17, a synchronization signal is extracted from the camera image and sent to the graphics drawing circuit 12. Supply synchronization separation circuit 10,
An image recognition device 15 for detecting a parking section that receives a signal from the camera 17 and performs image recognition of the parking section (parking space) 30 is provided. The image recognition device 15 can be provided separately from the controller 16.

The display 13 has a steering angle display marker 14 whose lighting state changes according to the state of the steering angle.
The left, right, or center of the display marker 14 is illuminated according to the state of the steering angle, so that it is possible to know in which direction the steering 21 is being turned together with the rear image. ing. Note that the steering steering angle here may be a steering angle (turning angle) from a neutral position when the steering wheel 21 is turned, or an actual steering angle in which the left and right wheels face from the traveling direction. . Also,
The description of the image recognition of the parking section 30 and the speech synthesis at the time of the parking operation is omitted here.

FIG. 2 is a mounting diagram when the parking assist device 1 is mounted on a vehicle. A camera 17 for imaging the rear is mounted near the upper center of the license plate behind the vehicle, and is installed with the optical axis directed downward from the horizontal direction. Specifically, as shown in FIG. 3, it is attached to the center of the rear of the vehicle at a downward angle θ of about 30 degrees from a horizontal state, and the camera itself secures a 140 ° left and right view with a wide-angle lens, An area up to about 8 m behind can be photographed.

A display 13 is provided on a panel surface of a center console in the cabin of the vehicle, and a controller 16 is provided above the glove box. Further, the parking switch 4 for requesting the parking assistance at the time of the parking operation is provided near the center console which is easy for the driver to operate.

Next, the steering sensor 2 will be described with reference to FIG. This steering sensor 2 is a commercially available one, and detects the steering angle of the steering 21. In this case, a slit plate 2a is mounted so as to rotate integrally with the steering column shaft 23, and two sets of photo interrupters 2c and 2b having a phase difference of 90 ° are mounted. In this configuration, by turning on / off the phototransistor by passing or blocking light by rotating a plurality of slits provided in a circumferential shape on the disk plate 2a, the A-phase and the B-phase
Two signal pulses are output. This means that the phase B is delayed by 90 ° or advanced ahead of the phase A depending on the rotation direction of the steering 21. In this case, the steering angle is 1 ° / pulse. Is used.

Next, the processing of the controller 16 will be described with reference to FIG. The controller 16 executes the program shown in FIG. 5 when the power is turned on (the accessory switch is turned on). First, in a first step S101, various initial values are set in a memory required for this processing, and in a subsequent step S102, the state of the shift reverse switch 3 is checked. here,
If the shift reverse switch 3 is off (not reverse), the display screen, that is, the screen of the display 13 is turned off in step S120, and a state change flag and a duration timer, which will be described later, are cleared, and the predetermined steering angle θREF is cleared.
Is substituted for the initial value (= 10 °), and the process returns to step S102.

On the other hand, when the shift reverse switch 3 is turned on (reverse state), step S103 is performed.
In step S103, the display 13 is switched to the camera image mode so that the image behind the vehicle can be displayed as a raw image. That is, in this case, a normal back monitor is used.

Next, after clearing the graphics screen (display screen) for drawing in step S104, the steering sensor 2 is cleared in step S105.
From the steering sensor value N, and the current turning radius R at the time of the parking operation is calculated based on the steering sensor value N. Specifically, when the reading of the steering sensor 2 is detected at the time of detecting the rising edge of the A-phase signal, an interrupt is generated in the main program, and the interrupt processing shown in FIG. 6 is executed. That is,
In step S201 of FIG. 6, the state of the B-phase signal is checked. If the B-phase signal is high (H: high potential), the steering count value N is incremented in step S202, and if it is low (L: low potential), it is decremented. The value is stored in the memory. In this case, the steering count value N is θ = N because one pulse is 1 °.

However, since the absolute steering angle of the steering wheel 21 is indeterminate only by counting the steering value N shown above, the neutral point of the steering angle is detected by the neutral point processing shown in FIG. And determine the neutral point. Therefore, the neutral point determination will be described with reference to FIG. This process is executed by a timer interrupt having a one-second cycle. Here, the vehicle speed is also normally calculated from signals from the known left and right wheel speed sensors 5 and 6 provided on the wheels.

In steps S301 and S302, the signals (pulses) from the left and right wheel speed sensors 5 and 6 are counted by a hardware counter built in the CPU 11 in the controller, and the left and right wheel speeds are read out in this timer interrupt routine. Then, the wheel speed sensor values are stored in the memories NR and NL. After reading,
The counter itself is cleared, and NR and NL indicate the number of pulses per second.

In the next step S303, the average value (NR + NL) / 2 is calculated from NR and NL, and this value is multiplied by the circumference of the tire, so that the vehicle speed V can be easily obtained by a known method. Next, regarding the reference setting of the steering sensor 2, in steps S304 to S306, when the vehicle speed is equal to or higher than the predetermined speed (10 km / h), the vehicle is driven in a state where there is almost no pulse difference between the left and right wheel speed sensors 5 and 6. Assuming that the vehicle is in the straight traveling state, the steering counter N is reset to zero in step S306, and the neutral point of the steering angle is obtained.

When the steering angle .theta. Is determined in step S105, the process returns to the main routine of FIG. 5, and then, in step S106, different cases such as a straight running state, a right turn, and a left turn are performed based on the steering angle .theta. That is, when the predetermined steering angle is θREF (> 0), θREF
Is negative and θREF is positive, left rotation is performed. If θ is equal to or more than −θREF and equal to or less than θREF (state 1), step S107 is executed. When the vehicle is turning right and θ is smaller than −θREF (state 2).
In step S112, the vehicle is turning left and θ is θRE.
If it is larger than F (state 3), step S113 is executed.

In the case of state 1 in step S106, it is next checked in step S107 whether or not the state change flag is clear. This state change flag indicates the fixed trajectory 26, 2 after entering the parking section 30.
7 is to be erased. Here, if the state change flag is set (state change is present), step S11 is performed.
1, but if the state change flag is cleared, the fixed trajectories 26 and 27 on both the left and right sides are determined in step S108.
Is superimposed on the screen of the display 13 on which the rear image is displayed.

The fixed trajectories 26 and 27 correspond to the steering 2
It is displayed on the basis of the trajectory of the rear outer wheel when 1 is fully or almost fully cut to the right or left, and is an index used to assist the driver in the parking operation during the parking operation. .

In the next step S109, a duration timer for counting the duration after the change of the turning state is checked, and here, it is determined whether the duration timer has passed a predetermined time (here, for example, 5 seconds). Is determined. If the duration timer has not elapsed the predetermined time (5 seconds) (if the state has just been changed), the process proceeds to step S111. If the predetermined time has elapsed, the state change flag is set in step S110. ,
In step S111, a predetermined steering angle (= 10
°).

On the other hand, if the steering angle is θ <−θREF (turn right) in step S106, only the right fixed trajectory 26 is displayed. Similarly, θ>
In the case of θREF (left turn), only the left fixed trajectory 27 is displayed, and the fixed trajectories 26 and 27 only in the steered direction (right or left) are displayed. Therefore, when the steering angle is near the neutral position (−θREF ≦ θ ≦ θREF),
The fixed trajectories 26 and 27 are displayed on the left and right only for a predetermined time, and the driver can know the trajectory of the vehicle when the steering angle is turned to the right or left to the maximum. In this case, when the steering wheel 21 is turned, one of the fixed trajectories 26 and 27 only in the turning direction is displayed, so that the driver can read the intention to park in the parking section 30 in which direction. Parking assistance according to the parking operation situation becomes possible.

Thereafter, in step S114, a state change flag is set, and in step S115, a predetermined steering angle θREF for switching the transition state of the steering angle is set.
Is set to 5 °. That is, by changing the value of θREF, the state transition is switched to the right steering, the neutral position, and the left steering, and the hunting when frequently performed near the steering angle (here ± θREF) is performed in a hysteresis characteristic. To prevent this.

Thereafter, in step S116, the following predicted travel locus 20 is calculated.

Next, a method of obtaining the predicted traveling locus 20 will be described below. This is because, as shown in FIG. 8, the turning center O at a low speed (here, 10 km / h or less) exists on the extension of the axle behind the vehicle, and the steering angle (steering angle) Corner) θ and the wheelbase L of the vehicle, the turning radius R is R = L /
It is obtained by the relational expression tan θ. In this case, when the steering angle θ = 0, the vehicle is traveling straight, and R = ∞.

FIG. 10 shows the coordinates (x, y) of graphics display on the camera, and FIG. 12 shows a method of coordinate conversion using the illustrated coordinate system. As shown in FIG. 11, the camera 17 is mounted at a height of Hc above the road surface with the optical axis inclined downward from the horizontal by θ = 30 °. The lens of the camera 17 is wide-angled and has a large depth of focus. The image of the road is drawn on the CCD device. Therefore, the following mapping relationship is established between the road surface coordinate system (X, Z) and the coordinate system (x, y) on the display.

Specifically, (X, Y, Z): road surface coordinates,
(X, y): camera coordinates on the CCD element surface, f: lens focal length of the camera, (x ′, y ′, z ′): lens coordinates,
θ: Camera mounting angle, Hc: Mounting height from the road surface, x = fxx / z ′, y = fy ′ / z ′ (1) x ′ = X, y ′ = x Zsinθ + (Y−Hc) cosθ｝ (2) The relational expression z ′ = Zcosθ− (Y−Hc) sinθ (3) holds. Here, if it is limited to only the coordinates on the road surface, Y = 0, and if x and y are obtained by the above relational expression, x = f × X / (Zcos θ + Hc × sin θ) (4) y = f (Zsin θ + Hc · cos θ) / (Zcos θ + Hc · sin θ) (5) That is, when the point (X, Z) on the road surface is photographed by the camera 17, the coordinates (x, y) on the graphics screen on the display can be obtained from the relational expressions of (4) and (5). it can.

When the (x, y) predicted travel locus 20 obtained by the above method is displayed on the display, various display methods are conceivable as shown in FIG. In other words, (a) shows a method of displaying the predicted track through which the left and right wheels of the vehicle pass, (b) shows a vector of the traveling area where the vehicle travels during parking, and (3) shows a constant distance interval (ladder interval: 50 cm). ) May be displayed in a ladder shape so that the user can easily understand the distance and the angle of the vehicle body at each position during the parking operation using (c). In this case, the expected vehicle trajectory 2
The length l of 0 is a fixed length (for example, 3 m), or a fixed angle, and the color is changed between a turning state (green) and a straight traveling state (blue). It is also possible to adopt a method of displaying only the parts easily.

FIG. 13 is an example of an actual display screen on the display 13, showing a state in which the predicted traveling trajectory 20, including the fixed trajectories 26 and 27, changes depending on the steering angle. This is the actual image behind the vehicle, for example,
According to the driver's preference, the ladder-like traveling schedules 20 can be displayed in an overlapping manner only when the parking switch 4 is turned on (a state where a parking assistance request is made). In this case, to know how much the driver is turning the steering wheel 21,
By displaying a display marker 14 for indicating the steering state of the steering angle together with a portion above or below the display 13, it is possible to visually recognize how much the steering is actually being performed. .

Next, in step S117, the predicted travel trajectory 20 obtained in step S116 is graphically drawn on the display 13 so as to overlap the rear image.
At step S118, the attention area 28 is displayed.
The attention area 28 is displayed on the own vehicle side of the display screen on which the rear image is displayed, and a place where the vehicle is likely to collide during the parking operation is displayed in a different frame shape having a display form different from that of the predicted travel locus 20. You. The caution area 28 is to alert the driver to a place where the vehicle is likely to collide, and to improve safety. Specifically, in the attention area 28, for example, in a rectangular display frame, the display form, particularly the display color, differs between the side 28b closer to the vehicle and the side 28a farther from the vehicle on the screen (red in the line next to 28b, 28a
(Displayed in yellow or the like on the line next to), it is possible to more clearly display the high-risk area where the bumper or the like of the own vehicle is likely to collide.

Thereafter, in step S119, the state of the shift reverse switch 3 is checked again. If it is not reverse (reverse), the display screen of the display 13 is turned off in step S120, and the flag and timer used for this processing are cleared. After further substituting the initial value (10 °) for θREF, the process returns to step S102.
If the state of the shift lever switch 3 is the reverse state, the process returns to step S104, and the above-described processing from step S104 is repeated. That is, at the time of the parking operation, the predicted traveling trajectory 20 is calculated and displayed based on the state in which the display of the fixed trajectories 26 and 27 is controlled according to the state of the steering angle. The trajectory 20 is variably displayed according to the steering angle (see FIG. 13).

Next, the parking sequence at the time of the parking operation according to the present invention will be described step by step based on the above processing. In (a), first, the fixed trajectories 26 and 27
Makes the vehicle back so that it touches the white line 31 of the parking section 30 on the far side, thereby adjusting the vehicle to the parking assist reference position. In this case, the camera 17 is installed at a position at a certain height above the ground at the center of the rear of the vehicle so that the optical axis is directed downward so that the state of the road surface behind is reflected, and the camera 17 is first set to an appropriate parking assistance reference position. Start by doing. First, the vehicle is stopped at the parking assist reference position such that the fixed trajectory 27 substantially extends ahead of the center of the white line 31. In this case, when the shift lever is in the reverse state, the screen shown in FIG. In this case, a case where the rudder angle is initially straight (straight traveling state) will be described as an example.

On the screen of the display 13, a predicted parking trajectory 20, a fixed trajectory line 26 on the right side, a fixed trajectory line 27 on the left side, and a caution area 28 are displayed together with a live image (rear image) of the rear parking lot. You. The fixed trajectory lines 26 and 27 correspond to the outer line (outer wheel line) of the rear wheel trajectory of the vehicle when the steering wheel 21 is turned almost to the right or left as described above. The estimated travel distance 20 is displayed as a ladder-like display of a fixed distance, and is displayed on a distance scale projected on the road surface. In this case, when an object behind and approaching behind is approached by the influence of the height of the object from the road surface, for example, the bumper of the rear vehicle is at the distance position of A 'on the display due to its height, In fact, it is closer to A (see FIG. 11). In the display of the attention area 28, the display frame is horizontally displayed at an average bumper height position to eliminate the difference, and the display color or the thickness of the display line is changed according to the degree of danger. The driver is informed of the danger of back contact.

In (b), the steering wheel 21 is then turned so that the predicted traveling trajectory 20 matches the fixed trajectory 27 on the left side in this case. Basically, the vehicle is stationary when the vehicle is stopped so that the predicted traveling trajectory 20 line coincides with the fixed trajectory 27. In this case, the steering wheel 21 is moved in a direction intended by the driver by a constant steering angle. When the steering is turned by θREF or more, the fixed trajectory 26 which is not on the turning side disappears from the display screen, and the fixed trajectory 27 only in the steering direction is displayed.

In (c), with the steering wheel 21 held in the state shown in (b), the driver looks back at the screen and directly and confirms the safety of the vehicle rearward or laterally and backs the vehicle. Approach.

In (d), the vehicle enters the parking space, and the steering wheel 21 is returned to the straight traveling state. in this case,
The driver visually determines the horizontal / vertical degree between the caution area 28 and the line of the parking section 30, and the display of the fixed trajectory line 27 disappears when the steering 21 is returned to the straight traveling state.

In (5), the driver stops backing while paying attention to the rear. However, in the last approaching state to the parking section 30, the parking white line 31 cannot be captured in the field of view with the current camera installation. Although the end stop position cannot be confirmed, when another vehicle is parked behind the own vehicle, the height of the position where the bumper of the subsequent vehicle will be (hatched portion (e))
Since the attention area 28 is displayed, the driver can be alerted to avoid collision during parking and contact with an object, and can appropriately assist parking. For this reason, even a driver who has a short driving history can easily determine the turning start position and the turning amount of the steering angle from the parking reference position, and can easily park.

When the parking assistance is performed as described above,
A predetermined voice signal is output from the speaker 8 by the voice synthesizing circuit 7, a predetermined voice message is output to the driver in accordance with the operation situation at that time, and guidance at the time of the parking operation is provided by voice. It is possible.

[0051]

According to the present invention, the rear of the vehicle is imaged by the camera during the parking operation, the image from the camera is displayed as a rear image on a display provided in the vehicle, and the rear image changes according to the state of the steering angle. In the parking assist device that displays the predicted traveling trajectory in a superimposed manner, the steering trajectory is maximized by displaying the fixed trajectory indicating the vehicle trajectory when the steering rudder angle is maximized on the rearward image. Since the fixed locus indicating the vehicle locus at the time is superimposed on the rear image, the driver turns the steering so that the predicted running locus coincides with the fixed locus. In other words, even beginners can perform parking operations with peace of mind.

In this case, assuming that the fixed trajectory is the vehicle trajectory on the turning outer wheel side during the parking operation, paying attention to the position through which the turning outer wheel passes, the turning outer wheel touches the white line of the parking section to assist parking. It is easy to determine the reference position.

When the fixed trajectory is displayed on both the right and left sides when the steering angle is near the neutral position, the trajectory of the vehicle when the steering angle is turned to the right or left can be determined. In both cases of turning right or left from the straight-back state during the parking operation, the fixed trajectory can be easily adjusted to the white line of the parking section.

If the fixed trajectory is displayed only in the turning direction at the time of the parking operation, the fixed trajectory is displayed only in the turning direction. Therefore, the driver reads the intention of the parking section in which direction. In addition, appropriate parking assistance can be performed while only necessary information is displayed on the screen.

If a caution area is further displayed on the own vehicle side of the screen on which the predicted traveling trajectory is displayed, a place where the vehicle is likely to collide during the parking operation is displayed as a caution area. If the area is given special attention, the collision of the vehicle is prevented and the safety is improved.

If the display area of the caution area is changed between the side closer to the own vehicle and the side farther from the own vehicle, it is possible to more clearly display the area with a high danger of collision, thereby improving safety. It will improve.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a parking assist device according to an embodiment of the present invention.

FIG. 2 is a mounting diagram when the parking assist device according to the embodiment of the present invention is mounted on a vehicle.

FIG. 3 is a diagram illustrating a detection range of a camera according to an embodiment of the present invention.

4A and 4B show a steering sensor according to an embodiment of the present invention, wherein FIG. 4A is a plan view of the steering sensor when attached to a steering column shaft, and FIG. 4B shows an outline of a slit plate and a photo interrupter of the steering sensor. FIG. 3C is a diagram showing the outputs of the A and B phases of the steering sensor.

FIG. 5 is a flowchart illustrating processing of a controller according to the embodiment of the present invention.

FIG. 6 is a flowchart illustrating steering sensor signal processing of a controller according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a neutral point process of the steering sensor of the controller according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram used for calculating a predicted traveling trajectory according to an embodiment of the present invention.

FIG. 9 is a diagram showing a display example of a predicted traveling trajectory according to an embodiment of the present invention, wherein (a) shows a display based on a predicted rut;
(B) is a diagram showing a running area belt display for the vehicle width, and (c) is a diagram showing a ladder-like display.

FIG. 10 shows graphics display coordinates of a camera and a display according to an embodiment of the present invention.

FIG. 11 is a diagram illustrating an attached state when the camera of the parking assist device according to the embodiment of the present invention is attached to a vehicle.

FIG. 12 is an explanatory diagram illustrating a coordinate conversion method of the parking assist device according to the embodiment of the present invention.

FIG. 13 is a display screen example of a display according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Parking assistance device 2 Steering sensor 3 Shift lever reverse switch 5 Right wheel speed sensor 6 Left wheel speed sensor 13 Display (display) 17 CCD camera (camera) 20 Expected trajectory 21 Steering wheel (steering) 26, 27 Fixed trajectory 28 Attention area 30 Parking lot 31 White line

Claims (6)

[Claims] An image of the rear of a vehicle is taken by a camera during a parking operation, and an image from the camera is displayed as a rear image on a display provided in the vehicle, and the rear image changes depending on the state of a steering angle. A parking assist device for displaying an expected trajectory superimposed on the rear image, wherein a fixed trajectory indicating a vehicle trajectory when the steering angle is maximized is displayed superimposed on the rear image. 2. The parking assist device according to claim 1, wherein the fixed trajectory is a vehicle trajectory on a turning outer wheel side during a parking operation. 3. The parking assist device according to claim 2, wherein the fixed trajectory is displayed on both the left and right sides when the steering angle is near the neutral position. 4. The parking assist device according to claim 3, wherein the fixed trajectory is displayed only in a steering direction during a parking operation. 5. The parking assist device according to claim 1, wherein a caution area is further displayed on the host vehicle side of the screen on which the predicted travel locus is displayed. 6. The parking assist device according to claim 4, wherein the display area of the attention area changes between a side closer to the own vehicle and a side farther from the own vehicle.