JP3562335B2 - Parking assistance device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a parking assist device for assisting parking of a vehicle, and in particular, captures a rear image with a camera, displays the rear image on a display (monitor display) in the vehicle, and performs a parking operation by a driver during a parking operation. The present invention relates to a parking assist device for assisting a vehicle.
[0002]
[Prior art]
Conventionally, there is known a method of assisting a beginner who is not used to parking such as parallel parking or garage parking during a parking operation. For example, in Japanese Patent Application Laid-Open No. 7-17328, a CCD camera and a distance sensor for measuring the distance are provided around the vehicle body to detect the surroundings of the vehicle, and a peripheral image around the vehicle is displayed on a display provided inside the vehicle. Is displayed in a bird's-eye view to provide the driver with the surrounding situation.
[0003]
Japanese Patent Application Laid-Open No. 59-201082 discloses a method in which a steering angle is detected by a steering sensor, the steering angle is calculated and output by a simple display. In a vehicle, a distance to an obstacle (especially 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, and the distance is measured according to the distance. There is known a method of detecting a turning start position based on a maximum steering angle and notifying a driver of the turning start position.
[0004]
[Problems to be solved by the present invention]
However, the above-described conventional method is based on the assumption that obstacles around the vehicle are detected using various sensing techniques, and a system for processing the obstacles becomes complicated. In addition, the method of measuring and notifying the distance to a nearby obstacle 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, Japanese Patent Application Laid-open No. Hei 10 (1998) -108566 proposes a parking assist device for assisting parking by a simple method and appropriately providing useful information to a driver during a parking operation. No. -14474. This device detects the rear of a vehicle (own vehicle) by a camera provided behind 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 has an advantage in that it can provide useful information about the surroundings to the driver when the vehicle is parked in the back. In consideration of the above, the operation situation is difficult to understand in the following points, and in particular, a beginner driver who has a short driving history needs some familiarization.
[0007]
That is, (1) it is difficult to determine the appropriate position for starting the back, (2) it is difficult to determine the turning start position and the turning amount of the steering wheel (steering), and (3) the timing of returning the steering after entering the parking section is determined. (4) It is difficult to determine the final stop position in the parking section.
[0008]
Therefore, the present invention has been made in view of the above-described problems, and it is a technical object of the present invention to provide a parking assist device in which even a novice can perform a parking operation with peace of mind and appropriately provide assistance during a parking operation. .
[0009]
[Means for Solving the Problems]
The technical measures taken to solve the above-mentioned problem are as follows: during parking operation, an image of the rear of the vehicle is taken by a camera, an image from the camera is displayed as a rear image on a display provided in the vehicle, and the rear image is steered. Varies depending on the steering angleOf the vehicleIn a parking assist device that displays the traveling trajectory in a superimposed manner,
At the time of the parking operation, if the steering angle is within a predetermined area, a left and right fixed trajectory indicating the vehicle trajectory when the steering angle is maximized is displayed on the display so as to overlap the rear image. When the vehicle is outside the predetermined area, the fixed trajectory only in the steering direction is displayed.did.
[0010]
According to this, left and right fixed trajectories indicating the vehicle trajectory when the steering steering angle is maximized are:When the steering angle is within a predetermined area,Since it is displayed superimposed on the rear image, it is possible to determine the parking assist reference position without turning, and then, if the driver turns the steering so that the expected traveling trajectory matches the fixed trajectory,Since the steering angle is outside the predetermined area and changes to a fixed trajectory only in the steering direction,The steering start position and the steering amount can be easily understood, so that even a beginner can perform a parking operation with ease.
[0011]
In particular,When the steering angle is within the specified areaThe vehicle is backed so that the fixed trajectory on the left and right displayed on the display unit is in front of the center of the white line of the parking section on the far side (indicating one parking space in a parking lot or the like) on the rear screen, A position at which one of the left and right fixed trajectories roughly touches the white line is defined as a parking assist reference position. When the parking assist reference position is reached, turn the steering wheel so that the predicted trajectory matches the fixed trajectory.When turning, the steering angle is out of the predetermined area, and the display changes to a fixed locus only in the turning direction.While holding the steering wheel at the steering angle that matches the expected travel trajectory, the vehicle backs up to the position approaching the parking section. 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 the position completely in parallel with the parking section. Thus, even a beginner can easily park.
[0012]
In this case, if 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, by making the turning outer wheel touch the white line of the parking section, the parking assist reference position is determined. It is possible to make the judgment easier.
[0013]
If the fixed trajectory is displayed on both the left and right 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 to the maximum can be determined. Sometimes, it is easy to match the fixed trajectory with the white line of the parking section in both the right turn and the left turn from the straight back state.
[0014]
If the fixed trajectory is displayed only in the steering direction during the parking operation, the fixed trajectory is displayed only in the steering direction, so the driver can read the intention of the parking section in which direction and read the intention. Thus, appropriate parking assistance can be performed while only necessary information is displayed on the screen.
Further, the predetermined area may include a neutral position of the steering angle, or the range may be changed depending on the steering angle.
[0015]
Further, in another technical means, an image of the rear of the vehicle is taken by a camera during a parking operation, an image from the camera is displayed on a display provided in the vehicle as a rear image, and a state of a steering angle is displayed on the rear image. A parking assist device that displays a predicted travel trajectory of the vehicle that changes by overlapping the rearward image,
A fixed trajectory indicating the vehicle trajectory of the vehicle when the steering rudder angle is maximized is superimposed and displayed on the rear image, and a measure of the approach distance to the bumper is given at the position of the bumper height of the vehicle. The attention area is displayed at the bottom of the screen.
On the screen where the predicted travel trajectory is displayedAttention area at the bottom of the screenIf displayed, the area where the vehicle is likely to collide during the parking operation will be displayed as a caution area, so if the driver pays special attention to this area when backing, the collision of the vehicle will be prevented and the safety will be improved I do.
[0016]
The attention area isThe display frame is displayed horizontally at the bottom of the screen,If the display form is changed between the side closer to the own vehicle and the side farther from the own vehicle, it becomes possible to more clearly display the area with a high risk of collision, and the safety is further improved.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
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 operating 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 based on these signals, 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. Further, the apparatus 1 is provided with a voice synthesizing function. The voice synthesizing circuit 7 outputs a voice synthesizing output, and the speaker 8 outputs a voice synthesizing output to the driver.
[0019]
Inside the controller 16 are a CPU 11 for controlling, a graphics drawing circuit 12 for drawing graphics on a display 13, a superimpose circuit 9 for superimposing a graphics signal and a rear image from the camera 17, and a synchronization signal from a camera image. A synchronization separation circuit 10 that extracts and supplies the extracted signal to the graphics drawing circuit 12 and 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 are provided. . The image recognition device 15 can be provided separately from the controller 16.
[0020]
The display 13 is provided with 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 lights up depending on the state of the steering angle. The direction in which the wheel 21 is steered can be recognized together with the rear image. Here, the steering angle may be a steering angle (steering 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. . 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.
[0021]
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 at the rear of the vehicle, and is installed with the optical axis directed downward from the horizontal direction. Specifically, as shown in FIG. 3, the camera is attached to the rear center of the vehicle at a downward angle θ of about 30 degrees from the horizontal state, and the camera itself secures a field of view of 140 degrees left and right by a wide-angle lens, An area up to about 8 m behind can be photographed.
[0022]
A display 13 is provided on a panel surface of a center console in a 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.
[0023]
Next, the steering sensor 2 will be described with reference to FIG. The steering sensor 2 is a commercially available one and detects the steering angle of the steering 21. The slit plate 2a is attached 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 attached. In this configuration, two A-phase and B-phase signal pulses are generated by turning on / off the phototransistor by passing or blocking light by rotating a plurality of slits provided on the disk plate 2a in a circumferential shape. Output. This is because the phase B is output with a phase delay of 90 ° or ahead of the phase A depending on the rotation direction of the steering 21, and here, the steering angle is 1 ° / pulse. Is used.
[0024]
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 step S101, various initial values are set in a memory required for this processing, and in step S102, the state of the shift reverse switch 3 is checked. 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, a duration timer, and the like, which will be described later, are cleared, and a predetermined steering angle is set. The initial value (= 10 °) is substituted for θREF, and the process returns to step S102.
[0025]
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 to set a mode in which an image behind the vehicle can be displayed as a raw image. That is, in this case, a normal back monitor is used.
[0026]
Next, after clearing the graphics screen (display screen) for drawing in step S104, the steering sensor value N is read from the steering sensor 2 in step S105, and the current turning radius R at the time of the parking operation is determined based on the value. Perform the calculation. 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, the state of the B-phase signal is checked in step S201 of FIG. 6, and if the B-phase signal is high (H: high potential), the steering count value N is incremented in step S202; if low (L: low potential), it is decremented. And stores the value in the memory. In this case, the steering count value N is θ = N because one pulse is 1 °.
[0027]
However, since the absolute steering angle of the steering 21 is undefined 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. Decide. 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.
[0028]
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 by this timer interrupt routine. The speed sensor value is stored in NR and NL of the memory where it is stored. After reading, the counter itself is cleared, and NR and NL indicate the number of pulses per second.
[0029]
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, the reference setting of the steering sensor 2 is performed. 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.
[0030]
When the steering angle θ is determined in step S105, the process returns to the main routine of FIG. 5, and then, in step S106, the cases of straight running, right turn, and left turn are performed based on the steering angle θ. That is, when the predetermined steering angle is θREF (> 0), when θREF is negative, right turning is performed, and when θREF is positive, left turning is set, when θ is −θREF or more and θREF or less (state In step 1), step S107 is executed. If the vehicle is turning right and θ is smaller than −θREF (state 2), step S112 is executed. If the vehicle is turning left and θ is larger than θREF (state 3), step S113 is executed. I do.
[0031]
In the case of state 1 in step S106, it is next checked in step S107 whether the state change flag is clear. This state change flag is for deleting the fixed trajectories 26 and 27 after entering the parking section 30. If the state change flag is set (the state change is present), the process proceeds to step S111. If the state change flag is cleared, the display of the fixed trajectories 26 and 27 on the left and right sides is displayed on the display 13 in step S108. On the screen on which the rear image of is displayed.
[0032]
The fixed trajectories 26 and 27 are displayed on the basis of the trajectory through which the rear outer wheel passes when the steering wheel 21 is fully or almost fully turned to the right or left, and assist the driver in the parking operation during the parking operation. This is the index used for
[0033]
In the next step S109, a duration timer for counting the duration after the turning state is changed is checked. Here, it is determined whether the duration timer has passed a predetermined time (here, for example, 5 seconds). You. If the duration timer has not elapsed the predetermined time (5 seconds) (if the status has just changed, the process proceeds to step S111). If the predetermined time has elapsed, the status change flag is set in step S110. In step S111, a predetermined steering angle (= 10 °) is substituted for θREF.
[0034]
On the other hand, if the steering angle is θ <−θREF (right turn) in step S106, only the right fixed trajectory 26 is displayed. Similarly, when θ> θREF (turn left), only the fixed trajectory 27 on the left side is displayed, and the fixed trajectories 26 and 27 only in the turning direction (right or left) are displayed. Therefore, when the steering angle is near the neutral position (−θREF ≦ θ ≦ θREF), first, the fixed trajectories 26 and 27 are displayed on the left and right only for a predetermined time, and the driver turns the steering angle to the maximum right or left. You can see the trajectory of the vehicle when passing. In this case, when the steering wheel 21 is turned, either 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 status becomes possible.
[0035]
Thereafter, a state change flag is set in step S114, and in step S115, the predetermined steering angle θREF for switching the transition state of the steering angle is set to 5 °. That is, by changing the value of θREF, the state transition is switched to the right turning, the neutral position, and the left turning, and the hunting when frequently performed near the steering angle (here, ± θREF) is performed in a hysteresis characteristic. To prevent this.
[0036]
Thereafter, in step S116, the following predicted travel locus 20 is calculated.
[0037]
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 an extension of the axle behind the vehicle, and the steering angle (steering angle) From the angle) θ and the wheel base L of the vehicle, the turning radius R is obtained by a relational expression of R = L / tan θ. In this case, when the steering angle θ is 0, the vehicle is traveling straight, and R = ∞.
[0038]
FIG. 10 shows graphics display coordinates (x, y) on the camera, and FIG. 12 shows a method of coordinate transformation using the illustrated coordinate system. As shown in FIG. 11, the camera 17 is mounted at a height Hc above the road surface with the optical axis inclined downward from the horizontal by θ = 30 °. The lens of the camera 17 has a wide angle and a large depth of focus. Then, an image of the road surface 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.
[0039]
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 = f · x ′ / z ′, y = f · y ′ / z ′ (1)
x '= X,
y ′ = Zsin θ + (Y−Hc) cos θ｝ (2)
z ′ = Zcos θ− (Y−Hc) sin θ (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 · (Z sin θ + Hc · cos θ) / (Zcos θ + Hc · sin θ) (5)
It becomes. 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.
[0040]
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. That is, (a) shows a method of displaying a predicted track through which the left and right wheels of the vehicle pass, (b) shows a vector of a traveling area where the vehicle travels when parking, and (3) shows a constant distance interval (ladder interval: 50 cm). ) Can be displayed in a ladder-like manner so that the user can easily understand the sense of distance and the angle of the vehicle body at each position during the parking operation using (c). In this case, the length l of the predicted vehicle trajectory 20 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). Further, it is also possible to adopt a method in which only the leading end of the expected trajectory is displayed so that it can be easily distinguished.
[0041]
FIG. 13 is an example of an actual display screen on the display 13 and shows a state in which the predicted traveling trajectory 20 including the fixed trajectories 26 and 27 changes depending on the steering angle. This is because the ladder-like traveling scheduled trajectory 20 overlaps the actual image behind the vehicle only when the parking switch 4 is turned on (in a state where there is a parking assistance request) according to the driver's preference, for example. It can also be displayed. In this case, a display marker 14 for indicating the steering state of the steering angle is displayed together on a part of the upper or lower side of the display 13 so that it is possible to know how much the driver is steering the steering 21. In addition, it is possible to visually recognize how much the vehicle is actually turning.
[0042]
Next, in step S117, the predicted traveling trajectory 20 obtained in step S116 is graphically drawn on the display 13 so as to be superimposed on the rear image, and further, the attention area 28 is displayed in step S118. 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 with the driver, thereby improving 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, If the horizontal line is displayed in yellow or the like), 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.
[0043]
Then, 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, the flag and timer used for this processing are cleared, and θREF is further set. After the initial value (10 °) is substituted into step S102, the process returns to step S102. If the shift lever switch 3 is in 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 travel 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).
[0044]
Next, the parking sequence at the time of the parking operation in the present invention will be described step by step based on the above processing. In (a), first, the vehicle is backed such that the fixed trajectories 26 and 27 are in contact with 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 from the ground at the rear center of the vehicle so that the optical axis is directed downward so as to show the state of the rear road surface, and is initially 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 steering angle is initially straight (straight traveling state) will be described as an example.
[0045]
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. 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 fully turned to the right or left as described above. The estimated travel distance 20 is displayed as a ladder-like display at a constant 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 on the display at a distance position of A '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 depending on the degree of danger. The driver is informed of the danger of back contact.
[0046]
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 line 20 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 vehicle turns beyond θREF, the fixed trajectory 26 that is not on the turning side disappears from the display screen, and the fixed trajectory 27 only in the turning direction is displayed.
[0047]
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 rear or side, backs the vehicle, and approaches the parking section 30. .
[0048]
In (d), the vehicle enters the parking space, and the steering 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.
[0049]
In (5), the driver stops backing while paying attention to the rear, but 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 attached, and the rear end stop. Although the position cannot be confirmed, when another vehicle is parked behind the own vehicle, the caution area 28 is displayed at the height (the shaded portion of (e)) where the bumper of the following vehicle will be located. Therefore, 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 start position and the amount of turning of the steering angle from the parking reference position, and can easily park.
[0050]
When the parking assistance is performed in this manner, a predetermined voice signal is output from the speaker 8 by the voice synthesis circuit 7, and a predetermined voice message is output to the driver according to the operation state at that time. It is also possible to provide guidance at the time of a parking operation by voice.
[0051]
【effect】
ADVANTAGE OF THE INVENTION According to this invention, the image of the back of a vehicle is imaged by a camera at the time of a parking operation, the image from a camera is displayed on a display provided in the vehicle as a rear image, and the running prediction that changes according to the state of the steering angle in the rear image. In a parking assist device that superimposes and displays tracks,During parking operation,Left and right fixed trajectories that indicate the vehicle trajectory when the steering steering angle is maximizedWhen the steering angle is within the specified rangeThe left and right fixed trajectories, which indicate the vehicle trajectory when the steering angle is maximized, are displayed so as to overlap with the rear image by superimposing it on the rear image.When the steering angle is out of the predetermined range, a fixed locus only in the steering direction is displayed.Therefore, if the driver turns the steering so that the expected traveling locus coincides with one of the left and right fixed locus, the starting position and the amount of turning of the steering can be easily understood, and even a beginner can perform the parking operation with peace of mind.
[0052]
In this case, if 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 is placed on the white line of the parking section, so that the parking assist reference position is determined. Makes judgment easier.
[0053]
If the fixed trajectory is displayed on both the left and right 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 to the maximum can be determined. Sometimes, it is easy to match the fixed trajectory with the white line of the parking section in both the right turn and the left turn from the straight back state.
[0054]
If the fixed trajectory is displayed only in the steering direction during the parking operation, the fixed trajectory is displayed only in the steering direction, so the driver should read the intention of the parking section in which direction to park and then read In addition, appropriate parking assistance can be performed while only necessary information is displayed on the screen.
[0055]
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 care is taken, collision of the vehicle is prevented, and safety is improved.
[0056]
Also, if the display area is changed between the near side and the far side of the own vehicle, it is possible to more clearly display the area where the risk of collision is high, thereby improving safety. It becomes.
[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 illustrating output of the A-phase and the B-phase of the steering sensor.
FIG. 5 is a flowchart illustrating processing of a controller according to an embodiment of the present invention.
FIG. 6 is a flowchart showing steering sensor signal processing of a controller according to the 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.
FIGS. 9A and 9B are diagrams showing display examples of a predicted traveling locus in one embodiment of the present invention, wherein FIG. 9A shows a display based on predicted ruts, FIG. 9B shows a traveling area belt corresponding to a vehicle width, and FIG. It is a figure showing a ladder 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]
1 parking assist 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 predicted running trajectory
21 Steering wheel (steering)
26, 27 fixed trajectory
28 Attention area
30 parking lot
31 White Line

Claims (6)

An image of the rear of the vehicle is taken by a camera at the time of parking operation, an image from the camera is displayed as a rear image on a display provided in the vehicle, and the predicted traveling trajectory of the vehicle changes depending on the state of the steering angle in the rear image. In the parking assist device that is displayed superimposed on the rear image,
At the time of the parking operation, if the steering angle is within a predetermined area, a left and right fixed trajectory indicating the vehicle trajectory when the steering angle is maximized is displayed on the display so as to overlap the rear image. The parking assist device displays the fixed trajectory only in the steering direction when the vehicle is outside the predetermined area. The parking assist device according to claim 1, wherein the fixed locus is a vehicle locus on a turning outer wheel side during a parking operation. The parking assist device according to claim 2, wherein the predetermined area includes a neutral position of the steering angle. The parking assist device according to claim 3, wherein a range of the predetermined area changes according to the steering angle. An image of the rear of the vehicle is taken by a camera at the time of parking operation, an image from the camera is displayed as a rear image on a display provided in the vehicle, and the predicted traveling trajectory of the vehicle changes depending on the state of the steering angle in the rear image. In the parking assist device that is displayed superimposed on the rear image,
A fixed trajectory indicating the vehicle trajectory of the vehicle when the steering rudder angle is maximized is superimposed and displayed on the rear image, and the approximate distance to the bumper at the bumper height of the vehicle is estimated. A parking assistance device characterized in that a given attention area is displayed at the bottom of the screen. The parking assist device according to claim 5, wherein a display frame of the attention area is horizontally displayed at a lower portion of a screen, and a display form is changed between a side closer to the vehicle and a side farther from the vehicle.

Images