JP2001315600A - Vehicular retreat support device and retreat support method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular retreat support device requiring no difficult operation even for a beginner, capable of performing parking operation without anxiety and properly assisting parking operation time. SOLUTION: In a parking assisting device 1 for superimposing and displaying a predictive locus 20 of a vehicle on a rear image on a display by taking the image of a vehicle rear part by a camera 17 at parking operation, a first predictive locus 20a according to a steering angle of the vehicle is displayed on the display at parking starting time. The first predictive locus 20a is fixed under a specific condition. The locus is set as a target locus. A second predictive locus 20' changing according to the steering angle at parking operation is displayed on the diaplay, and is guided and indicated so that the second predictive locus 20' is made to coincide with the target locus 20a with the fixed target locus 20a as an operational reference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse assisting device and a reverse assisting method for assisting backward movement of a vehicle. For example, when the vehicle is moved backward for parking or temporary evacuation, an image behind the vehicle is provided. The present invention relates to a device and a method for supporting a driver's retreat operation by displaying a rearward image and a predicted trajectory (predicted retreat trajectory) of the vehicle on a display (monitor) in the vehicle by photographing the vehicle.

[0002]

2. Description of the Related Art Conventionally, a method of assisting a beginner who is unfamiliar with parking such as parallel parking or garage parking during a parking operation has been known as a reverse support device. For example, JP-A-7-173
In Japanese Patent No. 28, a CCD camera and a distance sensor for measuring the distance are provided around the vehicle body, the surroundings of the vehicle are detected, and a peripheral image around the vehicle is displayed in a bird's eye view on a display provided inside the vehicle. 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, a steering angle at the time of parking operation is calculated, and a command angle and a steering angle are output by a simple display. I have. In Japanese Patent Application Laid-Open No. H8-2357, obstacles (particularly vehicles parked next to a parking space to be parked, etc.) are detected by a distance measuring sensor for detecting an object provided behind the vehicle. ) Is measured, a turning start position based on the maximum steering angle is detected in accordance with the distance, and a driver is notified of the turning start position.

[0004]

However, the above-mentioned 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. Because it ’s difficult and does n’t help parking properly,
It is difficult for a beginner to safely perform a parking operation.

In view of the above, the present invention has been made in view of the above-mentioned problems, and enables a beginner to perform a parking operation with peace of mind and a vehicle retreat assisting apparatus and a method for appropriately assisting the parking operation. To provide a technical issue.

[0006]

The technical measures taken to solve the above-mentioned problems include a camera (17) for photographing the rear of the vehicle at the time of parking operation, and displaying an image from the camera as a rear image. Display means (13), detection means (2, 3, 5, 6) for detecting a vehicle state, and an expected trajectory (2) based on the vehicle traveling based on information from the detection means and vehicle characteristics.
0), wherein the vehicle is provided with a calculation means (11) for calculating the predicted trajectory and superimposed on a rear image on the display means. Fixing means (4) for displaying the trajectory (20a) and fixing the first predicted trajectory when specific conditions are met
c), setting means (11) for setting the first predicted trajectory as the target trajectory (20a) when the first predicted trajectory is fixed by the fixing means, and changing according to the steering angle during parking operation. There is provided guidance means (8, 20) for displaying a second predicted trajectory (20 ') on the display means and guiding the second predicted trajectory with respect to the target trajectory.

According to this, at the start of parking, a first predicted trajectory corresponding to the steering angle is displayed on the display means, and the driver fixes the first predicted trajectory when specific conditions are met, so that the trajectory is displayed. After setting the target trajectory, the display means displays a second predicted trajectory that changes in accordance with the steering angle during the parking operation, so that the second predicted trajectory can be guided with respect to the fixed target trajectory. In this case, it is only necessary to perform an operation to match the second predicted trajectory with the reference target trajectory, so that a difficult operation is not required. For example, since there is no need to perform an operation of holding the steering wheel for a predetermined section, as in the case of parallel parking, even a beginner unfamiliar with parking does not need any difficult operation and can perform the parking operation with peace of mind.

[0008] In this case, if the guidance means is configured to perform the notification based on the target trajectory and the information from the detection means,
The amount of deviation from the target trajectory is calculated based on the fixed target trajectory and information (for example, the state of the shift lever, the steering state, the running state, etc.) from the detecting means, and the deviation amount or the positional relationship is calculated according to the calculated deviation amount or positional relationship. Since an appropriate notification can be made, the parking assistance during the parking operation is appropriately performed.

The specific condition is that when the first predicted trajectory is displayed in the direction in which the driver intends to park, if there is no obstacle in the first predicted trajectory, the driver's intention to park is respected. After confirming safety during parking operation,
Parking with a fixed expected trajectory becomes possible.

The technical means taken to solve the above-mentioned problems include a camera (17) for capturing an image behind the vehicle when the vehicle is moving backward, and a detecting means (2, 3, 5) for detecting the state of the vehicle moving backward. , 6), a calculating means for calculating an expected trajectory of the vehicle based on the retreat state and the vehicle characteristics, and a display means (13) for superimposing and displaying the expected trajectory on the vehicle rearward image. The predicted trajectory (20) is fixedly displayed on the display means as the target trajectory (20a), and the predicted trajectory (20 ') is displayed even after the target trajectory is displayed.
Is continuously displayed on the display means.

According to this, the expected trajectory is displayed, the expected trajectory at a certain time is fixedly displayed on the display means as the target trajectory, and after the target trajectory is displayed, the expected trajectory is continuously displayed. What is necessary is just to make the expected trajectory follow the target trajectory while observing the expected trajectory displayed on the means, so that even an inexperienced beginner can perform the operation without difficulty and without any operation.

The technical means taken to solve the above-mentioned problems include a camera (17) for capturing an image behind the vehicle when the vehicle moves backward, and a detecting means (2, 3) for detecting the state of the vehicle moving backward. Calculating means (11) for calculating an expected trajectory of the vehicle based on the retreat state and the vehicle characteristics;
The current predicted trajectory is displayed as a current trajectory (20), and the specified predicted trajectory is displayed as a target trajectory (20).
and a display means for fixedly displaying as a) and superimposing and displaying the vehicle rear image on the current / target trajectory.

According to this, display means for displaying the current expected trajectory as the current trajectory, fixedly displaying the specified predicted trajectory as the target trajectory, and superimposing and displaying the vehicle rear image on the current / target trajectory is provided. Since the driver is provided, the driver only has to perform an operation to match the current trajectory with the target trajectory superimposed on the image behind the vehicle, and even an unskilled beginner can perform the operation with ease without requiring difficult operations.

In this case, the reverse state is calculated based on at least the steering angle of the vehicle.
The reverse state can be accurately known based on the steering angle.

Since the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, the target trajectory can be set while respecting the driver's will when the vehicle retreats. Becomes

Further, the vehicle is provided with guidance means for guiding the driver of the vehicle by voice so that the current trajectory approaches the target trajectory, so that the current trajectory is guided by voice so as to approach the target trajectory. Guidance is possible.

[0017] Further, by providing guidance means for guiding the driver of the vehicle by display on the display means so that the current trajectory approaches the target trajectory, the display means is provided so that the current trajectory approaches the target trajectory. Therefore, appropriate guidance is possible.

Further, the technical measures taken to solve the above-mentioned problems include a step of capturing an image behind the vehicle when the vehicle retreats, a step of detecting the retreat state of the vehicle,
Calculating a predicted trajectory of the vehicle based on the retreat state and the vehicle characteristics; displaying the current predicted trajectory on a monitor as a current trajectory by superimposing the predicted trajectory on the rear image; The method further comprises the steps of: fixedly displaying the trajectory on the monitor as the target trajectory by superimposing the trajectory on the monitor; and displaying the current trajectory continuously after the fixed display of the target trajectory.

According to this, when the vehicle is moving backward, an image behind the vehicle is captured, and the state of the vehicle moving backward is detected. Based on the retreat state and the vehicle characteristics, an expected trajectory of the vehicle is calculated, the current expected trajectory is superimposed on the rear image and displayed as the current trajectory on the monitor, and then a specified expected trajectory is superimposed on the rear image. The target trajectory is fixed on the monitor and the current trajectory is displayed continuously after the fixed display, so if the driver operates so that the current trajectory matches the fixed target trajectory, difficult operations are required In addition, even unskilled beginners can operate safely when retreating.

In this case, since the reverse state is calculated based on at least the steering angle of the vehicle, the reverse state can be accurately known based on the steering angle.

Also, the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, so that the target trajectory can be set while respecting the driver's will when the vehicle retreats. Becomes

Further, since the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, the target trajectory can be set while respecting the driver's will when the vehicle retreats. Becomes

Furthermore, since the vehicle is provided with guidance means for guiding the driver of the vehicle by voice so that the current track approaches the target track, the vehicle is guided by voice so that the current track approaches the target track. , Appropriate guidance becomes possible.

[0024]

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

FIG. 1 is a system configuration diagram in the case where the reverse assisting device of the vehicle is applied to the parking assisting device 1. In this figure, a controller 16 for controlling the parking assist device 1 includes a CCD camera (hereinafter, referred to as a camera) 17 for photographing the rear of the vehicle, a steering wheel (steering) 21.
A steering sensor 2 for detecting a steering angle (also referred to as a turning angle) of the vehicle, a shift lever reverse switch 3 for detecting a reverse (R) state of a shift lever of a transmission, and parking for normal parking or parking. (Hereinafter, such a parking mode is referred to as parallel parking.) Or, parallel parking is instructed, or the locus 20 obtained from information on the vehicle is displayed, and the locus 20 is instructed to be fixed under specific conditions. Parking switch 4 (parallel switch 4a, tandem switch 4) for operating the parking assist function
b, a decision switch 4c), and signals from wheel speed sensors 5 and 6 for detecting the left and right wheel speeds of the driven wheels.

Based on these signals, the controller 16 can display an image behind the vehicle on the display 13 and a predicted travel locus 20 (20a, 20c, 20 ') described later. Further, the apparatus 1 is provided with a voice synthesis function. The voice synthesis circuit 7 outputs a voice synthesis output stored in a memory in advance, and the speaker 8 outputs a voice synthesis output to the driver. ing.

The controller 16 controls C.
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.

In the present embodiment, the display switch 13 is provided with a parallel, tandem, and fixed parking switch 4 of a touch panel type, but is not limited to this, and may be provided separately. Further, a steering angle display marker whose lighting state changes according to the state of the steering angle may be provided on the display. In this case, the display marker is left,
Either the right or the center is lit, and it is possible to know in which direction the steering wheel 21 is steered, together with the rear image. 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. . Further, the voice synthesis obtains a positional relationship between the vehicle state and the parking space 30,
A predetermined language is output from the speaker 8 to a memory in the CPU according to the relationship, and an appropriate instruction is issued to a driver (driver). While guiding.

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, it is attached to the center of the rear of the vehicle at a downward angle θ of about 30 degrees from the horizontal state, and the camera itself secures a 140 ° left and right field of view with a wide-angle lens and shoots an area up to about 8 m behind it can.

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 parking assistance during 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. 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,
Two sets of photointerrupters 2 with 90 ° phase difference
c, 2b 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 circular shape. Output (see FIG. 4). This means that the phase B is delayed by 90 ° or is output ahead of the phase A depending on the rotation direction of the steering 21, and the steering 21 is turned to the right by these two signals. You know whether you are turning or turning to the left.
In this embodiment, a steering angle of 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 (an accessory switch (not shown) provided in the vehicle is turned on). First, in a first step S101, various initial values are set in a memory necessary for this processing.
At 2, the state of the shift reverse switch 3 is checked. Here, if the shift reverse switch 3 is not reverse, the processing after step S102 is not performed, and the processing for parking assistance is not performed.

On the other hand, if the shift reverse switch 3 is ON (reverse state), step S103 is performed. First, it is determined from the state of the parking switch 4 provided on the display whether the driver is requesting normal parking operation (parallel parking) or parallel parking. In step S103, the state of the parking request is such that the processing from step S104 is performed when the parallel parking switch 4b shown in FIG. 12 is pressed, and the processing from step S118 is performed when the parallel parking switch 4a is pressed. Sorted by

(Parallel Parking) Here, parallel parking will be described first. When performing parallel parking, the driver presses the parallel parking switch 4a, and parallel parking processing starts.
In step S118, the steering sensor value N is read from the steering sensor 2, and the 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, 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. Then, the value is stored in the memory. In this case, the steering count value N is 1
Since the pulse is 1 °, θ = N.

However, since the absolute steering angle of the steering wheel 21 becomes 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 θ is determined, the process returns to the main routine of FIG. 5, and in the next step S119, the following predicted travel locus 20 (20a, 20 ') is calculated and displayed. Therefore, the predicted travel locus 20 (20
a, 20 ′) will be described.

As shown in FIG. 8, at low speed (here,
The turning center O of 10 Km / h or less exists on the extension of the axle behind the vehicle, and the turning center O is determined from the vehicle characteristics (steering steering angle (steering steering angle) θ and the wheel base L of the vehicle) due to a geometric relationship. The radius R is R = L / ta
It is obtained by the relational expression of nθ. In this case, when the steering angle θ = 0, the vehicle is traveling straight, and R = ∞.

FIG. 9 shows the graphics display coordinates (x, y) on the camera, and FIG. 11 shows a method of coordinate conversion using the illustrated coordinate system. As shown in FIG. 10, the camera 17 used here is mounted with the optical axis inclined downward by θ = 30 ° from the horizontal state at a height Hc above the road surface. The lens of the camera 17 has a wide angle and a large depth of focus, and is configured to draw an image of a road surface on a 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 (display color of the predicted travel locus 20 :, for example, yellow), such as in a garage or parking at a parking lot. In the case of parking (parallel parking) in which the front part of the vehicle is shaken at right angles, the display method is as shown in FIG. In this case, the length l of the predicted traveling trajectory 20 is a fixed length (for example, 3 m in parallel parking), is set to a fixed angle, and the color is changed between the turning state and the straight traveling state. Can be displayed easily.

In the next step S120, the rear end (the area including the leading end) 20c of the predicted trajectory 20 enters the parking space 30 intended by the driver within the white line, and the driver determines whether or not parking is possible. . Here, when it is determined that the parking is surely possible within the white line of the parking space 30, the driver presses the confirmation switch 4c on the display. After the confirmation switch 4c is pressed, the display of the confirmation switch 4c disappears. However, if the confirmation switch 4c is not pressed, the parking operation is hindered, and it is determined that accurate parking guidance cannot be performed.
Returning to step S102, the process from step S102 is repeated. If the enter switch 4c is pressed, the process from step S121 is performed. This confirmation switch 4c is
In the case of parallel parking, the direction of the predicted trajectory 20 corresponding to the steering rudder angle enters the parking space where the driver intends to park, and furthermore, the predicted trajectory 2 displayed by the left and right vehicle widths.
By pressing the button when there is no obstacle in the range of 0 (there is no object or other vehicle, or a state where no person is in the range), the driver can obtain the expected trajectory 2
It can be confirmed that there is no obstacle within the range of 0, and the expected trajectory 20 is determined after respecting the driver's will during the parking operation.
Can be fixed.

When the confirmation switch 4c is pressed, the screen display of the confirmation switch 4c disappears, and the predicted trajectory 20 displayed at that time is set as the target trajectory 20a which is used as a reference when assisting the parking operation. That is, the expected trajectory 20 becomes the target trajectory 20a under the specific condition. In this case, the display color of the target trajectory 20a when the trajectory is fixed as the target trajectory 20a is changed, for example, from yellow when undetermined to blue when confirmed. The reference line 20d also displays a reference line 20d (display color: red, for example) indicating a position separated by a predetermined distance (for example, 50 cm) behind the bumper of the vehicle in the vehicle width direction. I have to. The reference line 20d can give the driver a sense of distance to the obstacle in the rear image displayed on the display, and pay attention to a high-risk area where the bumper of the vehicle is likely to collide. The display is visualized as you go. A turning position reference line 20e indicating the turning position behind the reference line 20d (upward on the display) is displayed in the target locus 20a in the vehicle width direction in the same color as the target locus 20a.

In step S122, the movement distance of the vehicle is calculated by the CPU 11 from the information from the pulse waveforms output from the left and right wheel speed sensors 5 and 6, and at the same time, the steering angle is obtained by the same calculation method as in step S118. Can be In step S123, a command to display the target trajectory 20a from the current position to the rearmost end 20c of the target trajectory is issued from the CPU 11 to the graphics drawing circuit 12.
Output from the CPU 11 to the superimpose circuit 9
Is displayed on the display. Step S124
Then, the predicted trajectory 2 to the rearmost end 20c of the target trajectory 20a
0 'is obtained by the same method calculated in step S119, and is displayed on the display. In this case, the predicted trajectory 20 'is substantially the same as the predicted trajectory 20 that changes in accordance with the steering angle. Here, the predicted trajectory 20' indicates the trajectory after the target trajectory is set. And In step S125, the predicted trajectory 20 'variably displayed according to the steering angle and the fixed target trajectory 20a
Is calculated in the CPU 11 by calculation inside the CPU 11, and the driver is notified by display and sound based on the calculated shift amount in step S126.

Thereafter, in step S127, target locus 2
0a is determined by the movement distance based on the information from the left and right wheel speed sensors 5 and 6, and if the rear end 20c of the target trajectory 20a has not yet been reached, the process proceeds to step S118. Returning, the processing from step S118 to step S127 is repeated. On the other hand, step S
When the last end 20c reaches the last end 20c of the target trajectory 20a in 127, it is assumed that the parallel parking operation has been completed. In this case, by setting the shift lever to a state other than reverse, the driver determines from the state of the shift lever whether to end the parking operation.
Here, if the shift lever is still reverse, the process returns to step S122, and the processing from step S122 is repeated. When the shift lever is no longer reverse, the display on the display is set to the non-display state and the parking process ends.

(Parallel Parking) Next, the parallel parking process will be described. Usually, parallel parking stops the vehicle when the driver finds a space at the side of the road where parallel parking is available. After that, the steering wheel 21 is steered in a direction to be parked,
The vehicle is steered in the opposite direction by steering the steering wheel 21 in the opposite direction at a position lowered to a certain distance, and the vehicle is parked parallel to the curb 40 at a place where there is a shoulder or a sidewalk. This is because, as shown in FIG. 14, the vehicle travels on an S-shaped trajectory obtained by combining two arcs having different turning centers of the vehicle and moves back by distance L, and moves by D in the road width direction. Then, an operation to be parallel along the road is performed.

In this case, when considering a turning radius R, a distance L (= geometrically determined in advance by vehicle characteristics (wheel base, minimum turning radius, etc.) is considered.
Rsinθ, for example, about 6 m) (L is
If the predicted travel trajectory 20 is displayed on the display with a curve length (not the length), and if there is a parked vehicle or an object farther than the rearmost end 20c of the predicted travel trajectory 20, the own vehicle is in the initial position (see FIG. 14). It can be foreseen before parking operation that parking is possible from position a). in this case,
When performing a parking operation, when the steering wheel 21 is turned to the maximum steering angle or to an angle close to the maximum steering angle in a state where the vehicle is parallel to the vehicle that is parked in parallel near the own vehicle (initial parallel parking position). (Inflection point) An S-shaped expected trajectory 20 having a different turning center having PT is displayed. this is,
From the vehicle characteristics (steering characteristics), the steering 21
The turning radius R is determined in accordance with the amount by which the wheel is steered, the moving distance L in the front-rear direction necessary for shifting the width by a predetermined distance D is determined, and can be obtained geometrically by calculation. Therefore, conversion to a projection image viewed from the camera 17 is easy by the above-described method. As another method, the turning radius R of the vehicle can be obtained from the steering angle information from the steering sensor 2 mounted on the steering shaft and the steering gear ratio / wheel base of the vehicle. Specifically, in FIG. 15, the rotation angle from the initial state of parallel parking to the turning point PT of the steering 21 is θ, the vehicle width is Wr, and the vehicle width between the vehicle that is already in parallel parking and the vehicle that is going to perform parallel parking. When the center is D, a relational expression of D = 2R (1-cos θ) and D = Wr + d is obtained. For example, when R = 4 m, θ =
49.5 °, and the minimum distance for parallel parking is D =
6.08 m.

Returning to FIG. 5, the processing at the time of the parallel parking operation shown from step S104 will be described. Step S1
The processing from step 04 to step S106 is the same as the above-described processing during parallel parking. In the parallel parking process, the process starts from a state where the vehicle is first stopped at the position a shown in FIG. The position a is set to a state in which the vehicle is parallel to the vehicle parallel parked at a predetermined distance d (approximately 1 m) near the own vehicle. In this state, the steering wheel 21 is steered to display the expected S-shaped trajectory 20 on the display at the time of parallel parking, and the rear end 20c of the expected S-shaped trajectory 20 is parked behind the parking space. The first expected trajectory 20 is displayed in a state where the vehicle does not fall and the driver intends to park in parallel.
There are no obstacles in the area indicated by (No objects or other vehicles, or no people are in that area)
At this time, the confirmation switch 4c is pressed. in this way,
By providing the decision switch 4a on the display in the same manner as in the parallel parking at the time of the parallel parking operation, the driver's will at the time of the parking operation is respected, and the expected trajectory 20 is set as the target trajectory 20a as intended by the driver. A method is adopted in which the trajectory state is fixed and the trajectory state is fixed.

In step S108, the movement distance of the vehicle is calculated by the CPU 11 from information from the pulse waveforms output from the left and right wheel speed sensors 5 and 6, and at the same time, the steering angle is obtained by the same calculation method as in step S104. Can be In step S109, a command to display the target trajectory 20a from the current position to the rearmost end 20c of the target trajectory is issued from the CPU 11 to the graphics drawing circuit 12a.
Output from the CPU 11 to the superimpose circuit 9
Is displayed on the display. Step S110
In FIG. 14, an expected trajectory 20 'up to a turning point (coincident with the inflection point) PT shown in FIG.
The determination of (the target trajectory 20a is a trajectory that changes in accordance with the steering angle after the setting) is determined by the same method calculated in steps S105 and S119, and is displayed on the display. In step S111, the amount of deviation in the vehicle width direction between the predicted trajectory 20 ′ after setting the target trajectory 20a variably displayed according to the steering angle and the target trajectory 20a displayed and fixed by pressing the confirmation switch 4c is represented by CP.
It is obtained by calculation inside U11, and the driver is notified by display and voice based on the amount of deviation obtained in step S112. As described above, the guidance is performed by the display display and the voice synthesis, so that appropriate and reliable guidance can be performed during the parking operation.

Thereafter, in step S113, it is determined whether or not the state of the shift lever is a reverse state. Here, when the shift lever is not in the reverse state, it is determined that the parking operation is not necessary, the display is not displayed, and the parking process shown in FIG. 5 is ended. On the other hand, when the shift lever is not operated and the reverse state is still maintained, it is determined whether or not the vehicle has reached the turning point PT based on the traveling distance calculated in step S114. Here, in the case where the vehicle has not yet reached the turning point PT, the process returns to step S108 and returns to step S108.
The process from step 108 is repeated. When the vehicle reaches the turning point PT, it is determined whether the vehicle has reached the rearmost end 20c of the target locus 20a set in the initial stage of parking based on the travel distance calculated in the same manner. If the rear end 20c of the target trajectory 20a has not yet been reached, the turning point is updated in step S117, and the process returns to step S108 to repeat the same processing. Indicates that the parallel parking has been completed,
At 16, the trajectory display is not displayed, the display screen is turned off, and this processing ends.

Based on the above-described processing, the parking sequence at the time of the parking operation in the present invention will be described step by step.

(In the case of parallel parking) As a feature at the time of the parallel parking operation, the driver determines the possibility of parking using the predicted trajectory 20, and sets the predicted trajectory 20 when it is determined that parking is possible to the target trajectory 20a. To the target locus 20a
A method is adopted in which the parking trajectory 20 'is displayed so as to trace the upper part, and at the same time, the parking operation is appropriately guided by voice according to the situation. In this case, it is possible to select a method of resetting the target trajectory 20a and a method of displaying only the expected trajectory 20.

More specifically, FIG. 12 and FIG. 13 show that, ideally, about 2 m from the end of the parking white line 31 of the parking space 30.
Next, the vehicle is stopped in the R1 state shown in FIG. 12 (initial state). At this time, when the shift lever is put in reverse, the processing shown in the flowchart of FIG. 5 is performed. When the steering angle is in the straight traveling direction, the trajectory 20 calculated from the vehicle characteristics is displayed on the rear screen on the display as shown in FIG. In this state, the trajectory 20 is displayed in yellow including the rearmost end 20c, and a reference line 20d indicating the rear 50cm in the vehicle width direction is displayed in red so that the driver can recognize the sense of distance behind, and at the same time, the voice synthesis function is used. As a result, the message “Guided by parallel parking” is output from the speaker 8, the chime 1 (for example, a chime such as peen or pawn) sounds, and the “turn steering wheel turns the expected course to the parking section 30. Is pressed "is output from the speaker 8. When the vehicle state is R1 and the steering 21
Is operated to steer the steering angle so that the expected trajectory 20 is directed to the target parking section 30 as shown in FIG. After that, the driver presses the confirmation switch 4c below the display because the driver matches the target parking section 30.
When the confirmation switch 4c is operated, the trajectory 20 becomes the target trajectory 20a and is fixed, and the display color is switched to blue.

When the back is started, both the expected trajectory 20 'and the target trajectory 20a are displayed on the display.
After the message "Starting back" flows,
A chime 2 (for example, a chime in a form different from the chime 1) sounds, and a message “Backing Up” is output from the speaker 8. In this case, as shown in FIG. 12, if the vehicle is turning right and back, please pay attention to the right rear.
Is output from the speaker 8. FIG.
In FIG. 7, (c) shows a display screen on which the vehicle position is located at R2, and (d) shows a display screen on which the vehicle state is located at R3. Thereafter, the process moves to FIG. 13, and when the vehicle approaches the rearmost end 20c of the target trajectory 20a and reaches the rearmost end 20c as shown in FIG. Output. Then, as shown in FIG. 13 (b), the driver moves the predicted trajectory 20 so that it matches the fixed target trajectory 20a.
The driver presses c. Then, the expected trajectory 2 again
The target trajectory 20a is displayed together with 0 ', the "back starts", the chime 2 sounds, and the message "back with the steering wheel" is output from the speaker 8. The driver backs back while confirming the safety behind and, using the reference line 20d of 50 cm as a guide, performs backing while confirming the safety behind and reaches the rearmost end 20c of the target trajectory 20a as shown in FIG. 13 (c). If so, the parking operation ends. If it is desired to go further into the parking space 30, the processing from step S118 can be repeated.

(Case of Parallel Parking) Next, the case of parallel parking will be described with reference to FIGS. The feature during this parallel parking operation is that the S-shaped expected trajectory 20,
20 to determine the possibility of parallel parking, expected trajectory 2
0 is set as the target trajectory 20a, and a method of guiding the operation in parallel parking by voice while displaying the target trajectory 20a on the target trajectory 20a so that the predicted trajectory 20 'is substantially the same as the predicted trajectory 20 is displayed. I have. In this case, it is needless to say that when the vehicle deviates from the target trajectory 20a due to a delay in turning the steering operation or an excessive turning, the operation can be performed so as to return to the target trajectory 20a by referring to the predicted trajectory 20.

As shown in FIG. 16, when the vehicle is stopped in the state of L1 (a state in which the vehicle is parallel to an adjacent vehicle and is about 1 m away from the vehicle is set as an initial state), the shift lever is put in reverse, and the vehicle moves within the expected trajectory 20 or Make sure there are no vehicles or obstacles nearby. In this state, a message “Guided by parallel parking” flows from the speaker 8. Thereafter, the chime 1 sounds, and a message “If you can confirm the parking space by turning the steering wheel, press the confirmation switch” is output from the speaker 8. Then, the driver operates the steering wheel and checks a course where parallel parking is possible. When a course where parking is possible is found as shown in FIG. When the confirmation switch 4c is pressed, the display of the predicted trajectory 20 changes from yellow to blue, and the trajectory is fixed as the target trajectory 20a. After that, a message “start backing” flows, chime 2 sounds, and a message “back up” is output from speaker 8. In this state, both the target trajectory 20a and the predicted trajectory 20 corresponding to the steering angle are displayed. The driver is shown in FIG.
When turning to the left and back, a message "Please be careful for the right front" flows and approaches the position of the first turning point PT as shown in FIG. 16 (d). , The chime 2 sounds and a message "Please adjust the steering wheel" is output from the speaker 8. Then, the driver operates so that the expected trajectory 20 coincides with the target trajectory 20a as shown in FIG. afterwards,
When the vehicle state reaches the position of S3, since the vehicle is approaching the next steering position, the chime 2 sounds in the state shown in FIG. 17C, and the message "Please leave the steering wheel back as it is" is displayed. Is output from the speaker 8. Further, when the vehicle reaches the steered position as shown in FIG. 18 (a), the chime 1 sounds and "Please adjust the steering wheel".
The driver adjusted the steering angle,
An operation is performed to match the target trajectory 20a. In this case, since the vehicle has turned to the right and is back, in the state shown in FIG. 18 (b), a message "Please note the left direction" flows, and since the vehicle is approaching the goal, At the same time as the chime 1 sounds, a message "Please check the rear" flows, and since the vehicle has reached the goal as shown in FIG. 18 (c), the shift lever is put into the parking and the parking is completed.

As described above, when the parking operation is assisted, a voice signal predetermined by the voice synthesizing circuit 7 is output from the speaker 8, and a voice message predetermined according to the operation state at that time is output. Is output to the driver, and the guidance at the time of the parking operation is appropriately performed by voice, so that even a novice driver unfamiliar with parking can appropriately assist.

In the present embodiment, the parking assist device and its method have been described. However, the present invention is not limited to this. For example, when the oncoming vehicle arrives on a mountain road, a narrow road, or the like, the parking assist device is temporarily stopped. The present invention can also be applied to a backward support device or a method for retreating a vehicle, such as when the vehicle is moved backward.

[0060]

According to the present invention, at the start of parking, a first predicted trajectory corresponding to the steering angle is displayed on the display means, and the driver fixes the first predicted trajectory when a specific condition is satisfied. Is set as a target trajectory, and a second predicted trajectory that changes according to the steering angle during the parking operation is displayed on the display means.
It is possible to guide the predicted trajectory, and an operation may be performed so that the second predicted trajectory matches the reference target trajectory. Therefore, a difficult operation is not required in any parking mode.

In this case, if the notification is performed based on the information from the target trajectory and the vehicle state detecting means, the guidance means can set the target trajectory based on the fixed target trajectory and the information from the vehicle state detecting means. , And an appropriate notification can be made in accordance with the calculated shift amount or positional relationship, so that the parking assist can be appropriately performed during the parking operation.

The specific condition is that when the first predicted trajectory is displayed in the direction in which the driver intends to park, if there is no obstacle in the first predicted trajectory, the driver's intention to park is respected. After confirming safety during parking operation,
Parking with a fixed expected trajectory becomes possible.

According to this, the expected trajectory is displayed, the expected trajectory at a certain time is fixedly displayed on the display means as the target trajectory, and after the target trajectory is displayed, the expected trajectory is continuously displayed. What is necessary is just to make the expected trajectory follow the target trajectory while observing the expected trajectory displayed on the means, so that even an inexperienced beginner can perform the operation without difficulty and without any operation.

According to the present invention, the current predicted trajectory is displayed as the current trajectory, the specified predicted trajectory is fixedly displayed as the target trajectory, and the image behind the vehicle is displayed.
With the display means for superimposing and displaying the target trajectory, the driver only has to perform an operation to match the current trajectory to the target trajectory superimposed and displayed on the image behind the vehicle, and even an unskilled beginner does not need difficult operation. Operation can be performed with confidence.

In this case, the reverse state is calculated based on at least the steering angle of the vehicle.
The reverse state can be accurately known based on the steering angle.

Since the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, the target trajectory can be set while respecting the driver's will when the vehicle retreats. .

Further, since the vehicle is provided with guidance means for guiding the driver of the vehicle by voice so that the current locus approaches the target locus, the current locus is guided by voice so as to approach the target locus. Can be guided.

Further, the vehicle is provided with guidance means for guiding the driver of the vehicle by displaying on the display means so that the current trajectory approaches the target trajectory, so that the current trajectory approaches the target trajectory on the display means. Therefore, appropriate guidance can be performed.

Further, according to the present invention, when the vehicle is moving backward, an image behind the vehicle is captured, and the state of the vehicle moving backward is detected. Based on the retreat state and the vehicle characteristics, an expected trajectory of the vehicle is calculated, the current expected trajectory is superimposed on the rear image and displayed as the current trajectory on the monitor, and then a specified expected trajectory is superimposed on the rear image. The target trajectory is fixed on the monitor and the current trajectory is displayed continuously after the fixed display, so if the driver operates so that the current trajectory matches the fixed target trajectory, difficult operations are required In addition, even unskilled beginners can operate safely when retreating.

In this case, since the backward state is calculated based on at least the steering angle of the vehicle, the backward state can be accurately known based on the steering angle.

Since the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, the target trajectory can be set while respecting the driver's will when the vehicle retreats. .

Further, since the target trajectory is specified when the end of the predicted trajectory coincides with the desired vehicle retreat direction or position, the target trajectory can be set while respecting the driver's will when the vehicle retreats. .

Further, since the vehicle is provided with guidance means for guiding the driver of the vehicle by voice so that the current trajectory approaches the target trajectory, the vehicle is guided by voice so that the current trajectory approaches the target trajectory. , Can be properly guided.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram in a case where a vehicle backward support device according to an embodiment of the present invention is applied to a parking assist device.

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

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

FIG. 4 is a timing chart showing outputs of an A phase and a B phase of the steering sensor shown in FIG. 3;

FIG. 5 is a flowchart showing a process at the time of parking of the controller according to the 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 travel trajectory according to an embodiment of the present invention.

FIG. 9 shows graphics display coordinates of a camera and a display according to an embodiment of the present invention.

FIG. 10 is a diagram illustrating an attached state when the camera of the vehicle retreat assistance device according to the embodiment of the present invention is attached to the vehicle.

FIG. 11 is an explanatory diagram illustrating a coordinate conversion method of the vehicle backward assistance device according to the embodiment of the present invention.

FIG. 12 is a diagram illustrating an operation of parallel parking according to the embodiment of the present invention.

FIG. 13 is a diagram illustrating a parallel parking according to an embodiment of the present invention.
FIG. 3 is an operation explanatory diagram following FIG.

FIG. 14 is an operation explanatory view of parallel parking.

FIG. 15 is an explanatory diagram used for calculating a predicted traveling trajectory according to an embodiment of the present invention.

FIG. 16 is an explanatory diagram of an operation of parallel parking according to an embodiment of the present invention.

FIG. 17 is a view of parallel parking according to an embodiment of the present invention.
It is operation | movement explanatory drawing following 6.

FIG. 18 is a view of parallel parking according to an embodiment of the present invention.
It is operation | movement explanatory drawing following 7.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 parking assist device (reverse assistance device) 2 steering sensor (detection means) 3 shift lever reverse switch (detection means) 4 parking switch 4c determination switch (fixing means) 5, 6 wheel speed sensor (detection means) 7 voice synthesis circuit ( 8 Guidance means 8 Speaker (Guidance means) 9 Superimpose circuit 12 Graphics drawing circuit 11 CPU (Calculation means) 13 Display (Display means) 17 CCD camera (Camera) 20, 20 'Estimated trajectory (the current trajectory 2 predicted trajectory, guidance means) 20a travel predicted trajectory (first predicted trajectory, target trajectory) 21 steering wheel (steering)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60R 21/00 626 B60R 21/00 626G 628 628D 1/00 1/00 A B62D 6/00 B62D 6/00 15/02 15/02 H04N 7/18 H04N 7/18 J // B62D 101: 00 B62D 101: 00 113: 00 113: 00 137: 00 137: 00

Claims (14)

[Claims] 1. A camera that images the rear of a vehicle during a parking operation, a display that displays an image from the camera as a rear image, a detector that detects a vehicle state, information from the detector, and vehicle characteristics. Calculating means for calculating an expected trajectory relating to self-traveling based on the vehicle, and displaying the expected trajectory on the display means so as to be superimposed on a rear image. Fixing means for displaying an expected trajectory and fixing the first expected trajectory when specific conditions are met, and setting the first expected trajectory as a target trajectory when the first expected trajectory is fixed by the trajectory fixing means Means, and guidance means for causing the display means to display a second predicted trajectory that changes in accordance with a steering steering angle during a parking operation, and for guiding the second predicted trajectory with respect to the target trajectory. Retraction assistance device for a vehicle, characterized and. 2. The reversing support device according to claim 1, wherein the guidance unit performs notification based on the target trajectory and information from the vehicle state detection unit. 3. The specific condition according to claim 1, wherein when the first predicted trajectory is displayed in a direction in which the driver intends to park, there is no obstacle in the first predicted trajectory. 3. The reverse support device for a vehicle according to 2. 4. A camera that captures an image behind the vehicle when the vehicle retreats, a detection unit that detects a retreat state of the vehicle, and a calculation unit that calculates an expected trajectory of the vehicle based on the retreat state and vehicle characteristics. Display means for superimposing and displaying the vehicle rearward image and the expected trajectory, wherein the expected trajectory at a certain time is fixedly displayed on the display means as a target trajectory, and the expected trajectory is displayed even after the target trajectory is displayed. A reverse support device for a vehicle, wherein the display is continuously displayed on the display means. 5. A camera that captures an image behind the vehicle when the vehicle moves backward, a detecting unit that detects a state of the vehicle moving backward, and a calculating unit that calculates an expected trajectory of the vehicle based on the backward state and the vehicle characteristics. Display means for displaying the current predicted trajectory as a current trajectory, fixedly displaying the specified predicted trajectory as a target trajectory, and superimposing and displaying the vehicle rear image on the current / target trajectory. A reverse support device for a vehicle, comprising: 6. The device according to claim 5, wherein the reverse state is calculated based on at least a steering angle of the vehicle. 7. The vehicle according to claim 4, wherein the target trajectory is specified when the end of the predicted trajectory coincides with a desired vehicle retreat direction or position. Retreat support device. 8. The vehicle according to claim 4, further comprising: guidance means for guiding a driver of the vehicle by voice so that the current trajectory approaches the target trajectory. Retreat support device. 9. The vehicle according to claim 4, further comprising a guiding unit that guides a driver of the vehicle by a display on a display unit so that the current trajectory approaches the target trajectory. The vehicle reversing support device according to any one of the preceding claims. 10. A step of capturing an image behind the vehicle when the vehicle retreats, a step of detecting a retreat state of the vehicle, a step of calculating an expected trajectory of the vehicle based on the retreat state and vehicle characteristics, Superimposing the expected trajectory on the rear image and displaying the current trajectory on a monitor as a current trajectory; Continuously displaying the current trajectory even after the fixed display of the target trajectory. 11. The method according to claim 10, wherein the reverse state is calculated based on at least a steering angle of the vehicle. 12. The vehicle according to claim 10, wherein the target trajectory is specified when the end of the predicted trajectory coincides with a desired vehicle retreat direction or position. Retreat support method. 13. The vehicle according to claim 10, further comprising a step of guiding a driver of the vehicle by voice so that the current trajectory approaches the target trajectory. Retreat support method. 14. The system according to claim 10, further comprising a step of guiding a driver of the vehicle by a display on a display means so that the current trajectory approaches the target trajectory.
3. The method for backing up a vehicle according to any one of 3.