JP3138803B2 - Automatic vehicle steering system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic vehicle steering system for parking a vehicle without depending on a driver's steering operation.

[0002]

2. Description of the Related Art An automatic steering apparatus for such a vehicle is disclosed in Japanese Unexamined Patent Publication No. Hei.
No. 74256 and JP-A-4-55168. The automatic steering devices for these vehicles use an actuator of a conventionally known electric power steering device, and control the actuator based on a relationship between a moving distance of the vehicle and a steering angle stored in advance to control the back parking or the like. Parallel parking is performed automatically. Japanese Patent Application Laid-Open No. 62-278777 has already disclosed a device that issues a warning when an obstacle is detected in an expected movement trajectory of a vehicle during a parking operation by a driver.

[0003]

If an alarm device for detecting an obstacle and issuing an alarm is combined with an automatic steering device for a vehicle, automatic parking can be performed more reliably. However, the warning device described in the above-mentioned Japanese Patent Application Laid-Open No. 62-278777 has a possibility that the warning is issued immediately before the vehicle comes into contact with the obstacle, so that the avoidance operation may not be performed in time. When the warning is issued, the parking operation is restarted from the beginning, and the operation becomes an aspect.

The present invention has been made in view of the above circumstances, and has as its object to ensure that automatic parking control can be performed when an obstacle exists.

[0005]

According to the first aspect of the present invention, during automatic parking control, the determination means determines whether there is an obstacle present in the movement trajectory of the vehicle or intrudes into the movement trajectory of the vehicle. Since the presence or absence of the coming obstacle is determined, it is possible to take an avoidance measure when it is determined that the obstacle exists. In addition, when an obstacle already exists in the movement trajectory of the own vehicle at the time of starting the automatic parking control, it is not necessary to perform useless automatic parking control, thereby saving time.

According to the second aspect of the present invention, since the moving trajectory of the vehicle is stored as the turning angle of the wheel with respect to the moving distance of the vehicle, a constant movement is always maintained even if the vehicle speed during automatic parking control changes. The trajectory can be secured.

According to the third aspect of the present invention, when the determining means determines that there is an object serving as an obstacle, the notifying means notifies the driver, so that the driver can execute an operation to avoid the obstacle. .

According to the fourth aspect of the present invention, the automatic vehicle stopping means automatically stops the vehicle when the determining means determines that there is an object serving as an obstacle. Can be automatically avoided.

According to the fifth aspect of the present invention, when the driver operates the brake input means or shifts the automatic transmission to the parking range, the operation of the vehicle automatic stop means is released, so that the driver can perform a special operation. The operation of the automatic vehicle stopping means can be released without performing the above operation, and further, even if the operation of the automatic vehicle stopping means is released, the vehicle can be prevented from starting immediately.

According to the invention described in claim 6, since the front and rear wheels are steered, it is possible to make a small turn of the vehicle, and parking in a narrow place becomes easy.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 5 show an embodiment of the present invention. FIG. 1 is a diagram showing the overall configuration of a vehicle provided with a steering control device, and FIG. 2 is a diagram showing the positional relationship between a host vehicle, an obstacle, and a parking position. FIG. 3 is an explanatory diagram of the operation in the back parking / left mode. FIG. 4 is an operational explanatory diagram in the case where an obstacle is present in the trajectory of the vehicle. FIG. 5 is an obstacle entering the trajectory of the vehicle. It is an operation explanatory view in the case of performing.

As shown in FIG. 1, a vehicle V has a pair of front wheels W
f, Wf and a pair of rear wheels Wr, Wr. The steering wheel 1 and the front wheels Wf, Wf as the steered wheels, a steering shaft 2 that rotates integrally with the steering wheel 1, a pinion 3 provided at the lower end of the steering shaft 2, a rack 4 that meshes with the pinion 3, and a rack. 4 are connected by left and right tie rods 5 and 5 provided at both ends thereof and left and right knuckles 6 and 6 connected to the tie rods 5 and 5, respectively. Steering wheel 1 by driver
A steering actuator 7 composed of an electric motor is connected to the steering shaft 2 via a worm gear mechanism 8 in order to assist the operation of the vehicle or to perform automatic steering for garage described later.

The steering control device 21 includes a control unit 22 and a storage unit 2
3 and a determination unit 24.
Is the front wheel W based on the rotation angle of the steering wheel 1.
steering angle detecting means S for detecting the steering angle θ of f and Wf₁When,
A steering wheel for detecting the steering torque of the steering wheel 1
Luc detection means S_TwoAnd the rotation angles of the left and right front wheels Wf, Wf.
Front wheel rotation angle detection means S to be detected_Three, S_ThreeAnd the brake pedal
Brake operation detection hand that detects the operation (operation amount) of the dull 9
Step S_FourAnd the shift selected by the select lever 10
Range (“D” range, “R” range, “N” range,
Shift range detecting means S for detecting "P" range, etc.)_Five
And a total of 8 provided at the front, center and rear of the vehicle V
Object detection means S₆.. Are input. object
Body detection means S₆... is composed of known sonar or radar
Is done. The eight object detecting means S ₆... and the control unit 22
Are omitted to avoid complicating the drawing.
It is.

Further, a mode selection switch S ₇ and an automatic parking start switch S ₈ operated by a driver are connected to the control unit 22. Mode selection switch S
₇ is four kinds of parking modes described later, that is, back parking /
It is operated when selecting any of the right mode, the back parking / left mode, the parallel parking / right mode, and the parallel parking / left mode. Automatic parking start switch S ₈ is operated to start automatic parking according to any of the mode selected by the mode selection switch S _7.

The storage unit 23 stores in advance a table of the data of the four types of parking modes, that is, the relationship of the reference turning angle θref to the moving distance X of the vehicle V. Moving distance of the vehicle V X is calculated by multiplying the rotational angle of the front wheels Wf detected by wheel rotation angle detecting means S ₃ in the circumferential length of the front wheel Wf is known. The moving distance X
Is calculated by a pair of left and right front wheel rotation angle detecting means S ₃ , S ₃
Is used as the high select value, low select value, or average value.

The control unit 22 controls the signals from the detection means S _{1 to} S ₆ and the switches S ₇ and S ₈ , the parking mode data stored in the storage unit 23, and the obstacle determined by the determination unit 24. The operation of the steering actuator 7 and the brake actuator 12
(For example, a hydraulic actuator that controls the operation of the brake cylinders of the front wheels Wf, Wf and the rear wheels Wr, Wr) and the operation of the operation stage teaching device 11 including a liquid crystal monitor. The operation stage teaching device 11 is provided with a speaker for giving a voice instruction to the driver.

Next, the operation of the embodiment of the present invention having the above configuration will be described.

[0019] During normal not used to automatically parking (when the automatic parking start switch S ₈ is not ON), the steering control apparatus 21 functions as a general power steering control unit. Specifically, when the driver operates the steering wheel 1 to turn the vehicle V, a steering torque detecting means S ₂ detects the steering torque inputted to the steering wheel 1, the control unit 22 of the steering control apparatus 21 is the The steering actuator 7 is driven based on the steering torque. As a result, the left and right front wheels Wf, Wf are steered by the driving force of the steering actuator 7, and the steering operation of the driver is assisted.

Next, taking a back parking / left mode (a mode in which the vehicle is parked while backing to a parking position on the left side of the vehicle) as an example, an operation when the vehicle in the situation shown in FIG. 2 performs automatic parking will be described. explain.

[0021] First, when it reaches near the vehicle is parking position, the driver operates the mode selecting switch S ₇ selects the reverse parking / left mode, based on the eight object detecting means signals from the S ₆ ... The image of the surroundings of the own vehicle created as described above is displayed on the operation stage teaching device 11. That is, FIG.
(A) is an image of the operation stage teaching device 11 corresponding to FIG. 2, in which an image of two parked vehicles serving as obstacles, the position of the own vehicle indicated by ●, and an X mark , A shift position indicated by a circle (a position at which the vehicle is switched from forward to reverse), and an estimated movement path of the own vehicle from the own vehicle position to the parking position via the shift position. Further, the operation stage teaching device 11 provides the selected mode “back parking /
The character "left" and the character "forward", which is the current stage, are displayed.

[0022] The automatic parking start ON the switch S ₈ Then, "please slowly forward." In voice from the speaker that is connected to the operating stage teaching device 11 and the instruction is issued. When the driver is advanced creep running the vehicle by loosening the brake pedal 9, the driver without operating the steering wheel 1, front wheels Wf based on the data of the selected reverse parking / left mode by the mode selection switch S _7, Wf is automatically steered.

[0023] That is, the control unit 22 and norms steering angle θref of reverse parking / left mode read from the storage unit 23, on the basis of the θ turning angle inputted from the steering angle detecting means S ₁ deviation E ( = Θref−θ), and controls the operation of the actuator 7 so that the deviation E becomes zero. At this time, since the data of the reference turning angle θref is set in accordance with the moving distance X of the vehicle, the vehicle always moves on the moving locus even if the vehicle speed of the creep running varies.

When the vehicle approaches the shift position, FIG.
As shown in, the current stage displayed on the operation stage teaching device 11 changes from “forward” to “reverse preparation”,
The voice from the speaker indicates "Please prepare for reverse." When the vehicle reaches the shift position and the driver stops the vehicle and operates the select lever 10 from the “D” range to the “R” range, the operation stage teaching device 11 displays the operation lever as shown in FIG. The current stage changes from "reverse preparation" to "reverse", and the voice from the speaker instructs "please reverse slowly."

When the driver releases the brake pedal 9 based on an instruction from the speaker, the vehicle travels in a reverse creep along the moving path. Also in the case of the reverse creep running, the front wheels Wf, Wf are automatically steered based on the data of the back parking / left mode without the driver operating the steering wheel 1, as in the case of the forward creep running described above. When the vehicle reaches the parking position, the driver depresses the brake pedal 9 based on an instruction from the speaker to stop the vehicle, and the select lever 10
Is operated from the "R" range to the "P" range, thereby terminating the automatic parking control.

[0026] The automatic parking control by the steering control apparatus 21 described above, OFF the driver mode selection switch S ₇
It is released when the vehicle is turned off.In addition, it is released in the following cases and returns to the normal power steering control.In the case, the automatic brake is activated and the vehicle may come into contact with obstacles. Is prevented. When the driver releases the brake pedal 9 When the driver operates the steering wheel 1 When any of the object detection means S ₆ detects an obstacle First, when the driver releases the brake pedal 9 Will be described. The automatic parking control is executed while the driver performs the creep operation by depressing the brake pedal 9, and when the driver stops the brake operation, that is, when the driver releases his / her foot from the brake pedal 9, the brake operation detecting means When the operation amount detected by S ₄ becomes zero or becomes below the braking force which can suppress a creep running speed to a low speed, the automatic parking control is released to return to the normal power steering control.

As described above, by permitting the automatic parking control only when the driver operates the brake pedal 9 and the brake operation amount is small, the driver finds an obstacle by himself during the automatic parking control. When the vehicle is stopped, the brake operation can be performed without delay. If also like depresses the accelerator pedal to give up the driver is parked during the automatic parking control, for automatic parking control is canceled at the moment you release your foot from the brake pedal 9, OFF the driver mode selection switch S ₇ The operability is improved because there is no need to perform.

Next, a case where the driver operates the steering wheel 1 will be described. The driver does not need to operate the steering wheel 1 during the automatic parking control, but may put his hand on the steering wheel 1 in case of emergency. Driver during the automatic parking control to discover an obstacle or the like, when operating the steering wheel 1 in order to avoid the obstacle, the automatic parking control when the steering torque detecting means S ₂ detects the steering torque larger than a predetermined value It is released. In this way, by canceling the automatic parking control when the driver operates the steering wheel 1, interference between the driver's obstacle avoidance operation and the automatic parking control is prevented, and smooth obstacle avoidance becomes possible.

Next, any one of the aforementioned object detecting means S ₆
Will be described when an obstacle is detected. By continuously detecting obstacles existing around the vehicle by the eight object detection means S ₆ , the determination unit 24 determines whether or not the stopped obstacle already exists in the movement trajectory of the own vehicle. Further, in the case of a moving obstacle such as a small animal, it is determined whether or not the estimated trajectory of the obstacle may enter the trajectory of the own vehicle.

FIG. 4 shows a case where at the start of the automatic parking control, a part of the two parked vehicles protrudes into the movement trajectory of the own vehicle and becomes an obstacle. In this case, the sound from the speaker informs that "there is an obstacle in the expected movement trajectory." At the same time, the portion where the vehicle and the obstacle interfere with each other is displayed on the screen of the operation stage teaching device 11 by blinking. At the same time, the text "obstruction exists in the movement locus" is displayed. In this case, it is clear that automatic parking control cannot be performed due to the presence of an obstacle at a stage before the automatic parking control is executed, so that it is not necessary to perform useless automatic parking control, and time is saved.

FIG. 5 shows that during the reverse movement in the automatic parking control,
This shows a case where a small animal or the like may enter the movement locus of the vehicle and become an obstacle. In this case, the voice from the speaker informs the user that "an obstacle is approaching. Please be careful." At the same time, the vehicle and the obstacle may interfere on the screen of the operation stage teaching device 11. The portion is displayed by blinking or the like, and the character "obstacle approaching" is displayed.

When the determining unit 24 determines that there is a possibility that the own vehicle interferes with the obstacle, the brake actuator 12 is operated by a command from the control unit 22 to automatically stop the vehicle. At the same time, the automatic parking control is released. As described above, by canceling the automatic parking control by detecting the obstacle, when the driver voluntarily performs the obstacle avoiding operation, the interference between the obstacle avoiding operation and the automatic parking control is prevented.

[0033] When the automatic braking as described above is actuated, the driver voluntarily brake operation detecting means S ₄ depresses the brake pedal 9 detects the pedaling force equal to or greater than a predetermined value or, or the driver of the select lever 10 Operating the "P" range cancels the operation of the automatic brake. This eliminates the need for the driver to perform a special release operation, and improves operability.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the first embodiment, an image around the own vehicle created based on the output of the sonar or the radar is displayed on the screen of the operation stage teaching device 11, but in the second embodiment, the image is provided on the vehicle. An image taken by the television camera as the object detection means S ₆ ... Is displayed, and the moving trajectory of the own vehicle is superimposed on this image. Although all eight sonars and radars of the first embodiment may be replaced by television cameras, or some of them may be replaced by television cameras, at least one television camera is provided before and after the vehicle.
When the vehicle is moving forward, the video taken with the TV camera at the front of the vehicle is projected. It becomes possible to grasp.

FIGS. 7 and 8 show a third embodiment of the present invention. FIG. 7 is an overall configuration diagram of a vehicle provided with a front and rear wheel steering control device, and FIG. 8 is an operation explanatory diagram.

In the second embodiment, the front wheels Wf, Wf and the rear wheels Wf
The present invention is applied to a front and rear wheel steering vehicle capable of steering r and Wr, and includes a steering actuator 7 'for rear wheels Wr and Wr in addition to a steering actuator 7 for front wheels Wf and Wf.

When the front wheels Wf, Wf and the rear wheels Wr, Wr are to be independently steered, the storage unit 23 stores the standard steering angles of the rear wheels Wr, Wr in addition to the standard steering angles θref of the front wheels Wf, Wf. θref is stored, and the front wheels Wf, Wf and the rear wheels W
r and Wr are the reference steering angles θre.
The control unit 22 controls the operation of both steering actuators 7, 7 'so that f is satisfied.

When the steering angle θ of the rear wheels Wr, Wr is controlled in proportion to the steering angle θ of the front wheels Wf, Wf, only the reference steering angle θref of the front wheels Wf, Wf is stored in the storage unit 23. The control unit 22 controls the operation of the steering actuator 7 so that the turning angle θ of the front wheels Wf, Wf becomes the reference turning angle θref, and controls the rear wheels Wr, Wr.
The operation of the steering actuator 7 'is controlled such that the turning angle θ of the steering wheel 7 becomes a value proportional to the reference turning angle θref.

As described in FIGS. 2 to 5, the space required when the front-wheel-steered vehicle of the first embodiment is parked in the back parking / left mode is the space shown by hatching in FIG. Becomes The space required when the front-rear-wheel steering vehicle of the third embodiment is parked in the back parking / left mode is a small space indicated by oblique lines in FIG. 8C, which is shown in FIG. 8B. The areas a and b are as small as possible and are as close as possible to the space.

By doing so, a plurality of movement trajectories can be set at the same parking place, the number of cases where obstacles can be avoided is increased, and the frequency of use of automatic parking control is greatly increased.

[0042] In the third embodiment, to the driver by providing a selecting means such as a switch near the driver's seat may be allowed to select the front-wheel steering or rear wheel steering, the detection result of the object detecting means S ₆ The size of the parking space may be determined on the basis of this, and the front wheel steering or the front and rear wheel steering may be selected based on this.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

[0044]

As described above, according to the first aspect of the present invention, during the control of the steering actuator based on the contents stored in the storage means, the control signal exists in the movement locus based on the output of the object detection means. Means for judging the presence or absence of an object that becomes an obstacle and / or an obstacle that intrudes into the movement trajectory by means of a vehicle, so that the vehicle does not contact the obstacle during automatic parking control. Can be taken. In addition, if an obstacle already exists in the movement trajectory of the vehicle at the start of the automatic parking control, useless automatic parking control does not need to be performed and time is saved.

According to the second aspect of the present invention,
Since the storage means stores the moving trajectory of the vehicle as the turning angle of the wheel with respect to the moving distance of the vehicle, a constant moving trajectory can be secured regardless of the magnitude of the vehicle speed during the automatic parking control.

According to the third aspect of the present invention,
The provision of the notification means for notifying the driver when the determination means determines that there is an object serving as an obstacle can urge the driver to perform an operation to avoid the obstacle.

According to the invention described in claim 4,
The provision of the automatic vehicle stopping means for automatically stopping the vehicle when the determining means determines that there is an object serving as an obstacle can automatically avoid contact with the object serving as an obstacle.

According to the invention described in claim 5,
Since the vehicle is provided with an automatic transmission, the operation of the automatic vehicle stopping means is released by the driver's operation of the brake input means or the shift of the automatic transmission to the parking range. It is possible to prevent the vehicle from starting immediately.

According to the invention described in claim 6,
Since the wheels to be steered are the front and rear wheels, it is possible to make a small turn of the vehicle and facilitate parking in a narrow place.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle including a steering control device.

FIG. 2 is a diagram illustrating a positional relationship among a vehicle, an obstacle, and a parking position.

FIG. 3 is an explanatory diagram of an operation in a back parking / left mode.

FIG. 4 is an explanatory diagram of an operation when an obstacle is present in a movement locus of a vehicle.

FIG. 5 is an explanatory diagram of an operation when an obstacle enters a moving path of a vehicle.

FIG. 6 is a view according to a second embodiment and corresponding to FIG. 3;

FIG. 7 is an overall configuration diagram of a vehicle including a front and rear wheel steering control device according to a third embodiment.

FIG. 8 is a diagram illustrating the operation of the third embodiment.

[Explanation of symbols]

7 Steering Actuator 7 'Steering Actuator 9 Brake Pedal (Brake Input Means) 11 Operation Stage Teaching Device (Announcement Means) 12 Brake Actuator (Automatic Vehicle Stopping Means) 22 Control Unit (Control Means) 23 Storage Unit (Storage Means) 24 Judgment Unit (determination means) S ₆ object detecting means V vehicle Wf front (wheels) Wr rear wheel (wheel) theta turning angle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-74256 (JP, A) JP-A-4-55168 (JP, A) JP-A-62-278477 (JP, A) 200479 (JP, A) JP-A-4-160608 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 6/00 B62D 7/14

Claims (6)

(57) [Claims] 1. A steering actuator (7, 7 ') for turning a wheel (Wf, Wr) based on a steering operation of a driver, and a brake input means (9) operated by a driver.
A storage means (23) for storing in advance a movement trajectory of the vehicle (V) to a target stop position; and a steering actuator (7) based on the storage contents of the storage means (23) instead of the driver's steering operation. , 7 ′), and an object detecting means (S ₆ ) for detecting an object around the vehicle (V), wherein the storage means (23) wherein during control of the steering actuator (7, 7 ') based on the stored contents of, based on the output of the object detection means (S _6), the presence to the object and / or the movement that becomes an obstacle to the movement in the trajectory Determining means (24) for determining the presence or absence of an object that enters the trajectory and becomes an obstacle
An automatic steering device for a vehicle, comprising: 2. The storage means (23) stores a movement locus of the vehicle (V) as a steered angle (θ) of a wheel (Wf, Wr) with respect to a movement distance of the vehicle (V). The automatic steering device for a vehicle according to claim 1, wherein 3. An informing means (11) for informing a driver when said judging means (24) judges that the obstacle is present. Automatic vehicle steering system. 4. A vehicle automatic stopping means (12) for automatically stopping a vehicle (V) when said determining means (24) determines that there is an object serving as said obstacle. Item 3. An automatic steering device for a vehicle according to item 1 or 2. 5. The vehicle (V) includes an automatic transmission,
The vehicle according to claim 4, wherein the operation of the vehicle automatic stop means (12) is released by an operation of the brake input means (9) by a driver or a shift of the automatic transmission to a parking range. Automatic steering system. 6. The automatic steering apparatus for a vehicle according to claim 1, wherein the steered wheels (Wf, Wr) are front and rear wheels.