JP5262087B2 - Parking assistance device - Google Patents

Description

  The present invention relates to a parking assistance device that allows a driver to easily park by assisting a driving operation in parking.

Conventionally, for example, Patent Document 1 discloses a parking assist device that can notify a driver of a turning start position of a steering device at the time of parking to reduce a driving operation burden. In this case, when the turning start position of the steering device is notified, the driver stops the vehicle and turns the steering device.
JP, 2001-334899, A For example, in patent documents 2 etc., parking assistance which eases a driver's burden at the time of parking by using an automatic brake and stopping a vehicle by steering return timing and making a driver steer. A device has been proposed. Japanese Patent Laid-Open No. 2003-11760

  As described in Patent Documents 1 and 2, the purpose of causing the driver to stop and steer the vehicle is to enable accurate parking at the parking target position. However, when the vehicle is stopped and the driver steers, a series of operations such as stopping the vehicle, steering operation, and starting must be performed in order, so that it takes time to complete the parking operation. There is.

  An object of this invention is to provide the parking assistance apparatus which can complete parking operation efficiently, maintaining favorable parking accuracy in view of said subject.

In order to achieve the above object, the invention according to claim 1 is characterized in that route setting means for setting a parking route for moving a vehicle to a parking target position, and the parking route set by the route setting means, Route determination means for determining whether the parking route requires a steering operation by a driver in the middle of the parking route, relative position detection means for detecting a relative position of the vehicle with respect to the parking target position, and the route determination When the driver moves the vehicle to a parking target position according to the parking route that is determined to require the steering operation, the vehicle decelerates without stopping the vehicle when the driver performs the steering operation. and speed adjusting means for performing speed control of the vehicle, the steering operation by decelerating the vehicle by the speed adjusting means before the driver to the steering operation to open the And a steering angle detection means for detecting a steering angle of the steering device, wherein the speed adjustment means includes the parking path and the relative position detected by the relative position detection means. When the vehicle reaches a predetermined position on the parking route, the speed adjustment is started, and when the steering angle of the steering device detected by the steering angle detection means matches the predetermined steering angle. It is a parking assistance apparatus characterized by ending the speed adjustment.

  According to the first aspect of the invention, the speed of the vehicle is adjusted so as to keep the vehicle moving when the driver steers. That is, when the driver steers, the speed adjusting means suitably adjusts the speed of the vehicle without stopping the vehicle. Therefore, even if steering is performed while moving, the amount of movement during that time can be shortened, so the error in the parking route is reduced. For this reason, the parking operation can be completed efficiently while maintaining good parking accuracy.

According to the fourth aspect of the present invention, since the operation direction of the operation of the steering wheel matches the steering direction of the steering operation calculated based on the parking route set by the route setting means, the driver performs the steering. The direction to do can be intuitively grasped and the steering operation can be performed immediately, so that the parking operation can be completed efficiently.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
FIG. 1 is a schematic view showing a vehicle 2 equipped with a parking assistance device 1 of the present embodiment.
As shown in the figure, the parking assist device 1 includes a camera (CCD camera) 11 that captures a rear view of a vehicle 2, a steering angle sensor 13 that detects a steering angle of a steering wheel 12 as a steering device, and a transmission A shift lever reverse switch 14 for detecting a reverse (reverse) state of a shift lever (not shown), a parking switch 15 for operating a parking assist function at the time of parking operation, and a vertical change of the vehicle 2 as a change in the vehicle angle as the vehicle 2 turns. A yaw rate sensor 16 for detecting the rotational angular velocity in the axial direction, a monitor screen 17, a speaker 18, a vehicle speed sensor 19 for detecting the speed in the traveling direction of the vehicle 2, a controller 20, and an automatic brake device 27 are provided.

  The camera 11 is installed with the optical axis directed downward, for example, at a substantially central portion behind the vehicle 2. Specifically, as shown in FIG. 4, the camera 11 is attached to be inclined downward at a predetermined angle (for example, 30 degrees) at the center at the rear of the vehicle. As shown in FIG. 5, the camera 11 itself has a wide-angle lens to secure a field of view of, for example, 140 degrees to the left and right, and can capture an area up to, for example, about 8 m behind.

  The steering angle sensor 13 is a general-purpose sensor that detects the steering angle of the steering wheel 12. For example, the steering angle sensor 13 is provided inside the steering wheel 12.

The parking switch 15 is a switch for operating a parking assist function, and is provided, for example, in the vicinity of the center console that can be easily operated by the driver. The parking switch 15 has two mode switches that can be selected according to the parking mode, that is, a parallel parking mode switch 15a that operates a parking assist function in parallel parking (garage storage) and a column that operates a parking assist function in parallel parking. A parking mode switch 15b is provided (see FIG. 2).

  The monitor screen 17 is installed on the center console, for example. In the display area shown in FIG. 6 of the monitor screen 17, a graphic image such as a rear end predicted locus, which will be described later, is displayed together with a rear image (raw image) of the vehicle 2 photographed by the camera 11.

  From the speaker 18, required voice guidance is output (spoken) corresponding to each stage of a parking operation described later.

  The controller 20 is provided, for example, inside an instrument panel, and a graphic image such as a rear image of the vehicle 2 and a predicted rear end trajectory on the monitor screen 17 based on input signals from the camera 11 and sensors 13 to 16. And a required voice guidance is output from the speaker 18.

  The automatic brake device 27 adjusts the speed of the vehicle 2 by controlling the brake pressure of the vehicle 2 based on the output value from the CPU 21.

  FIG. 2 is a system configuration diagram of the parking assistance device 1. As shown in the figure, inside the controller 20 that controls the parking assist device 1, there are a central processing unit (CPU) 21, a graphics drawing circuit 22 that draws graphics on the monitor screen 17, A superimpose circuit 23 that superimposes the graphics signal and the rear image from the camera 11, a synchronization separation circuit 24 that extracts a synchronization signal from the camera image and supplies it to the graphics drawing circuit 22, and an output from the speaker 18 to the driver. A voice synthesis circuit 25 for synthesizing voice guidance is provided.

  FIG. 3 is a functional block diagram of the parking support apparatus 1 in the present embodiment. As shown in FIG. 3, the parking support apparatus 1 in the present embodiment includes a route setting unit 101, a route determination unit 102, and a relative position detection unit. 103, speed detection means 104, rudder angle detection means 105, start determination means 106, and speed adjustment means 107.

  The route setting means 101 is a means for setting the parking route 40 for moving the vehicle 2 to the parking target position, and is configured to be executed by the CPU 21. The parking route 40 set by the route setting means 101 will be described later.

  The route determination unit 102 is a unit that determines whether or not the parking route 40 set by the route setting unit 101 is a parking route that requires steering by the driver, and is configured to be executed by the CPU 21. Yes.

  The relative position detection means 103 detects a relative position of the vehicle 2 with respect to the parking target position. The CPU 21 is configured to detect the relative position of the vehicle 2 with respect to the parking target position based on detection information of the steering angle sensor 13 and the yaw rate sensor 16 constituting the steering angle detection means 105.

  The speed detection unit 104 includes a vehicle speed sensor 19 that detects the speed of the vehicle 2.

  The rudder angle detection means 105 includes a rudder angle sensor 13 that detects the rudder angle of the steering wheel 12 as a steering device.

Next, the start determination unit 106 and the speed adjustment unit 107 will be described.
First, the speed adjusting means 107 adjusts the speed of the vehicle 2 when it is determined that the parking route 40 requires steering by the driver in the route determining means 102. The speed adjustment is performed for the purpose of causing the vehicle to travel while maintaining a state that substantially matches a parking path 40 described later when the steering is performed. The CPU 21 calculates an output value of feedback control so that the speed of the vehicle 2 detected by the speed detecting means 104 is equal to or lower than a predetermined value, and outputs the output value to the automatic brake device 27 to decelerate the vehicle 2. Has been. The start of speed adjustment is configured to be based on the start time of speed adjustment determined by the start determination means 106 described later.
Further, based on the rudder angle information of the rudder angle detection means 105 and the parking route 40, the speed adjustment is terminated when the steering operation by the driver is terminated.

  The start determining unit 106, like the speed adjusting unit 107, determines that the parking route 40 needs to be steered by the driver in the route determining unit 102, and the relative position detected by the parking route 40 and the relative position detecting unit 103. And the speed adjustment start time is determined based on the speed information detected by the speed detecting means. In the present embodiment, the CPU 21 is configured to execute. Further, when the start determination means 106 determines the start time of the speed adjustment, it is determined that it is the timing at which the steering is started by the voice guide means (not shown) constituted by the CPU 21, the speaker 18, and the voice synthesis circuit 25. Inform the person.

The timing for starting the steering may be notified to the driver that it is the timing for starting the steering based on a change in the speed of the vehicle 2 by the speed adjusting means 107.
Further, as indicated by a broken line in FIG. 3, the automatic steering means 108 is further provided, and based on the determination result of the start determination means 106, the automatic steering means 108 operates the steering wheel to start the steering. It can also be configured to notify the driver. Further, in this configuration, the automatic steering means 108 is based on the parking route 40 set by the route setting means 101 (not shown), and the direction of operation of the steering wheel is made to coincide with the steering direction of the steering. It can also be configured to notify the steering direction of the steering.

  Next, in order to describe the parking route 40 set by the route setting means 101, the geometrical relationship between the initial position of the vehicle 2 and the guided position when performing parallel parking in the space S on the left side as viewed from the driver. The relationship will be described based on the plan view of FIG. The position where the vehicle 2 is guided is calculated by the controller 20 in response to the driver's operation when starting parallel parking. As shown in the figure, the vehicle 2 is parallel to the direction in which the space S extends in both the initial position and the guided position. Note that the movement distance dL in the vertical direction (rear) and the movement distance dW in the horizontal direction (left side direction) associated with this guidance indicate movement distances of the substantially middle point O of the center axis of the rear wheel. ing. The space S is set to a length L and a width W. The length L and width W of the space S are unique values obtained by giving a slight margin to the minimum necessary space defined by the specifications of the vehicle 2.

  The initial position of the vehicle 2 is laterally separated by a distance w from the reference point P of the space S to the left end of the vehicle 2 and is longitudinally extended from the reference point P of the space S to the center axis of the rear wheel ( It is assumed that the distance l is separated (backward). At this time, the initial position of the vehicle 2 is set and constrained so that the straight line m connecting the reference point P of the space S and the camera 11 and the direction in which the space S extends always forms a predetermined angle α (ratio l / w is set and constrained to be a substantially constant value). In addition, the guided position of the vehicle 2 determined by the moving distances dL and dW is set and constrained so that the straight line n parallel to the straight line m and the direction in which the space S extends form an equal angle α. Has been. As a result, the position at which the vehicle 2 is guided and the reference point P are maintained at a constant interval in the vertical direction.

Next, the movement of the substantially middle point O of the center axis of the rear wheel accompanying parallel parking will be described. Here, based on the steering angle of the steering wheel 12, a predicted rear end locus (such as a turning radius) is calculated by a known method (for example, a method according to the method described in Japanese Patent Laid-Open No. 11-334470). In the present embodiment, when the steering angle of the steering wheel 12 is determined by steering for the left turn in the first half, the steering angle after turning back the steering wheel 12 in the second half is set to the maximum steering angle. The guiding position is uniquely determined. That is, when the steering angle of the steering wheel 12 is determined by steering for the left turn in the first half, the turning radius at that time (first turning radius R1) is determined. On the other hand, since the steering angle after turning back the steering wheel 12 in the latter half is set to the substantially maximum steering angle, the turning radius at that time is defined by a second turning radius R2 (specified by the specifications of the vehicle 2). Minimum turning radius + extra length is desirable). Then, the tangents of the respective expected trajectories of the substantially middle point O of the central axis of the rear wheels associated with both turns are such that the turning angles θ in the left turn of the first half and the right turn of the second half are equal to each other. The steering points 45 are set so as to coincide with each other. As a result, the steering point 45 is arranged on a straight line k connecting the turning center O1 having the first turning radius R1 and the turning center O2 having the second turning radius R2, and each turn in the first left turn and the second right turn. The angles θ are equal to each other.

From the above, the moving distances dL and dW of the substantially middle point O of the center axis of the rear wheels accompanying parallel parking are respectively
dL = (R1 + R2) · sin θ
dW = (R1 + R2). (1-cos θ)
It is expressed. That is, the steering angle of the steering wheel 12 (the first turning radius R1 and the turning angle θ) is determined by steering for the left turn in the first half, so that the position where the vehicle 2 is guided is uniquely determined.

  Here, the parking route 40 set by the route setting means 101 is an expected locus of the approximate middle point O of the central axis of the rear wheel from the initial position of the vehicle 2 to the position (parking target position). Accordingly, the parking path 40 in FIG. 7 includes an arc from the substantially middle point O of the center axis of the rear wheel at the initial position of the vehicle 2 to the steering point 45 (center O1, an arc corresponding to the angle θ of the radius R1), steering It is composed of both arcs at a substantially intermediate point O of the center axis of the rear wheel at a position where the vehicle 2 is guided from the point 45 (center O2, arc corresponding to the angle θ of the radius R2).

In FIG. 7, if the moving distance dW substantially matches the value obtained by adding the width W and the distance w (dW = W + w), the distance l and the distance w, that is, the vehicle 2
The position of the reference point P with respect to the initial position is specified. This reference point P is the position of an obstacle such as the right rear end of a vehicle that has already been parked. Accordingly, by setting and restraining the initial position of the vehicle 2 (constraining the relative position between the vehicle 2 and the obstacle), the obstacles such as the already parked vehicle and the vehicle 2 when guiding the parallel parking described above. The parking route 40 which avoids a contact with is set.

  Further, at the position where the vehicle 2 is guided, the distance from the central axis of the rear wheel to the rear end of the space S is set to be separated in the vertical direction by a predetermined distance ΔL. This predetermined distance ΔL is a distance with a slight margin in the distance from the center axis of the rear wheel to the rear end of the rear bumper. Accordingly, the setting of the predetermined distance ΔL prevents the rear portion of the vehicle 2 from deviating from the space S. In other words, the length L of the space S in the above calculation is set to a length obtained by adding an extra length to the length defined by the specifications of the vehicle 2 required when parking in the above-described manner. .

  Next, the parallel parking operation and the processing mode of the controller 20 corresponding to this will be described with reference to FIGS. The processing operation by the controller 20 is activated when the parallel parking mode switch 15b of the parking switch 15 is selected (turned on). Incidentally, FIG. 9 shows the state of the vehicle 2 when it is parked in parallel in the parking frame S 1 on the left side as viewed from the driver. 10 to 12 show the image and voice guidance of the monitor screen 17 output by the controller 20 corresponding to each stage of the state of the vehicle 2, the state in which the switching of the stage is determined by the controller 20, and the same determination. The main devices used and the driver operations are shown respectively. The controller 20 performs guidance by dividing a series of driver operations in parallel parking into the following four operations.

1. Setting of parking start position ... (1), (2)
2. Setting of parking target position ... (3), (3-2)
3. Turn left backward ... (4), (5)
4). Turn right backward ... (6), (7)
Here, the number written in the driver's operation name corresponds to the number of the image (display state) on the monitor screen 17 in FIGS.

1. Setting of parking start position: The driver, for example, has a space in the lateral direction with respect to the adjacent vehicle 2a, and the front-rear direction of the vehicle 2 is substantially parallel to the parking frame S with respect to the predetermined parking frame S 2 to be parallelly parked. Stop to become. The stop position at this time is a position slightly ahead of the steering start position of the steering wheel 12 when it is assumed that the vehicle can be parked in the parking frame S 2 when the steering wheel 12 is moved backward while being steered. In this case, in FIG. 10, after the parallel parking mode switch 15b is pressed, the shift lever is in the reverse state. However, the present invention is not limited to this, and the timing for pressing the parallel parking mode switch 15b and the shift lever are in the reverse state. Either may be the timing first.

  The driver who stops the vehicle 2 selects (turns on) the parallel parking mode switch 15b of the parking switch 15, and operates the parking assist function in the parallel parking. At this time, as shown in the state (1) in FIG. 10, the CPU 21 displays the predicted rear end locus a of the vehicle 2 calculated according to the rear image and the steering angle by the camera 11 on the monitor screen 17.

  Here, the expected rear end locus a is, for example, the vehicle 2 calculated by a known method (for example, according to the method described in JP-A-11-334470) based on the steering angle at that time. The expected rear end trajectory on the horizontal road surface is converted into the CCD element position of the camera 11, that is, the monitor screen 17 using a well-known coordinate transformation (for example, the one conforming to the coordinate transformation described in JP-A-11-334470). The display position is made to correspond in real time and is superimposed and drawn on the monitor screen 17.

  Next, when the driver puts the shift lever in the reverse state, the shift lever reverse switch 14 is turned on, and the CPU 21 detects that the shift lever is in the reverse state.

Then, the CPU 21 “starts guidance” from the speaker 18 via the speech synthesis circuit 25, “backs up until“ b ”meets the rear end of the adjacent vehicle”, “turns the handle to“ C ”. Output to fit the parking frame. " At the same time, as shown in the state (2) in FIG. 10, the CPU 21 displays the azimuth reference line b on the monitor screen 17 in addition to the rear image by the camera 11 and deletes only the expected rear end locus a.

  Here, as shown in FIG. 7, the azimuth reference line b changes the position of the vertical plane B having a predetermined azimuth with respect to the camera 11 of the vehicle 2 to the display position of the monitor screen 17 using the same coordinate transformation. It is made to correspond and is superimposed and drawn on the monitor screen 17. The vertical plane B represented by the azimuth reference line b is set at a position that does not substantially contact an obstacle disposed on the vehicle front side of the vertical plane B when parallel parking is performed in a manner described later. In other words, on the monitor screen 17, by aligning the azimuth reference line b with the right rear end of the adjacent vehicle 2a, a position where contact with the adjacent vehicle 2a is substantially avoided is specified.

  In this state, the driver follows the voice guidance and moves the vehicle 2 in a straight traveling state until, for example, the azimuth reference line b substantially coincides with the right rear end of the adjacent vehicle 2a in the rear image. Then, the driver stops when the bearing reference line b substantially coincides with the right rear end of the adjacent vehicle 2a (state (2)). Thereby, the relative position of the right rear end of the vehicle 2 and the adjacent vehicle 2a, that is, the ratio l / w in FIG. 7 is restrained. Therefore, the right rear end (reference point P) of the adjacent vehicle 2a exists on the straight line m 1.

  Subsequently, the driver follows the voice guidance and steers the steering wheel 12 to the left at that position.

When the driver steers the steering wheel 12 in the state (2), the CPU 21 detects this operation via the steering angle sensor 13. When it is determined that the steering angle of the steering wheel 12 is equal to or greater than the predetermined threshold value, the CPU 21 outputs “back when 'C” is in the parking frame ”from the speaker 18 via the voice synthesis circuit 25, The state shifts to the state (3) in FIG.
2. Setting of parking target position: In the state (3), the CPU 21 displays the parking target frame C on the monitor screen 17 in addition to the rear image by the camera 11 and the direction reference line b.

  Here, the parking target frame C is, for example, the contour of the vehicle 2 on a horizontal road surface at the position where the vehicle 2 is guided based on the above-described calculation, to the display position of the monitor screen 17 using the same coordinate transformation. It is made to correspond and is superimposed and drawn on the monitor screen 17. Accordingly, the parking target position (parking target frame C) of the vehicle 2 exists on a straight line n parallel to the straight line m in FIG. 7, and the longitudinal and lateral movement distance DL is based on the steering amount of the steering wheel 12 by the driver. , DW and the parking path 40 at that time are restrained.

  Here, the front end of the parking target frame C substantially coincides with the position of the front bumper of the vehicle 2, for example, and the rear end substantially coincides with the position slightly behind the rear bumper of the vehicle 2, for example. ing. This is for setting a parking position with a margin without contacting the rear vehicle 2b.

  In this state (3), the driver follows the voice guidance and steers the monitor screen 17 until the parking target frame C is aligned with the target position of the parking frame S 1 in the rear image (such as the shoulder of the parking frame S 1). The wheel 12 is steered (state (3-2)). At this time, since the distance w 1 is roughly obtained as described above, the distance l 2 is based on the restrained ratio 1 / w, that is, the right rear end of the adjacent vehicle 2a at the initial position (reference point P in FIG. 7). Relative position is specified. Based on the relative position of the restrained / identified parking path 40 of the vehicle 2 and the right rear end (reference point P in FIG. 7) of the adjacent vehicle 2a at the initial position, the contact with the adjacent vehicle 2a associated with this parallel parking is determined. Presence / absence is determined.

  In addition, when the contact with the adjacent vehicle 2a accompanying parallel parking is determined, the CPU 21 displays, for example, a request to reset the steering angle of the steering wheel 12 on the monitor screen 17 or outputs from the speaker 18. On the other hand, when the non-contact with the adjacent vehicle 2a due to the parallel parking is determined, the CPU 21 displays the parking target frame C at that time on the monitor screen 17 as it is.

  As described above, the driver avoids the contact between the vehicle 2 and the adjacent vehicle 2a, and the parking path 40 for moving the vehicle 2 to the position indicated by the parking target frame C and the steering wheel 12 at the time of the left turn at that time. Obtain the rudder angle at the same time. Therefore, after setting the parking target position (parking target frame C), the driver may simply move the vehicle 2 backward without adjusting the steering angle of the steering wheel 12.

  In the state (3-2), the driver follows the voice guidance and starts to reverse the vehicle 2 while keeping the steering wheel 12 steered. When the driver starts to reverse the vehicle 2, the CPU 21 uses the rudder angle sensor 13 and the yaw rate sensor 16 to indicate the change amount (left turn amount) of the vehicle angle from the state (3) accompanying the left turn of the vehicle 2 at this time. To detect. CPU21 which comprises the relative position detection means 103 has detected the relative position of the vehicle 2 and the parking frame S (parking target position) based on the variation | change_quantity of this vehicle angle. When a change in the vehicle angle is detected by the rudder angle sensor 13 and the yaw rate sensor 16, the CPU 21 determines that the vehicle 2 has started to move, and shifts to the state (4). At this time, the CPU 21 outputs, from the speaker 18 via the speech synthesis circuit 25, “The handle is left as it is”. At the same time, as shown in the state (4), the CPU 21 displays the rear image and the expected rear end locus a by the camera 11 on the monitor screen 17 and deletes the azimuth reference line b and the parking target frame C.

3. Left turn backward: In the state (4), the driver continues the backward movement of the vehicle 2 while keeping the steering wheel 12 in accordance with the voice guidance.

  Hereinafter, a description will be given of the flowchart of FIG. 13 showing the processing of the CPU 21 up to the right turn backward and the driver's operation associated therewith.

  First, in step S1 corresponding to the route determination unit 102, it is determined whether or not the parking route 40 is a parking route that requires steering by the driver. That is, when the vehicle 2 is a parking route that requires steering halfway when the vehicle 2 moves backward along the parking route 40 as in the parking route 40 of FIG. 7, YES is determined in step S1. For example, if the parking path 40 is composed of only one turning circle, steering by the driver is not required halfway when retreating along the parking path, and therefore, step S3 and subsequent steps in this flowchart are not executed. .

  In the subsequent step S2, “mode”, which is a variable for storing the state in this flowchart, is initialized with zero. Note that mode = 0 indicates a state before speed adjustment.

  In step S3, it is determined whether it is a calculation cycle. In FIG. 13, the processing after step S4 is performed at a calculation cycle of every 10 ms.

  In step S4, based on the parking path 40 and the relative position detected by the relative position detecting means 103, the movement distance L1 (hereinafter referred to as the movement distance L1 when moving along the parking path 40 from the current position of the vehicle 2 to the steering point 45). , “The moving distance L1 to the steering point 45”). In the present embodiment, an arc (an angle θ1 between the center O1 and the radius R1) between the steering point 45 and a substantially middle point O3 of the center axis of the rear wheel of the vehicle 2 that is moving backward along the parking path 40 shown in FIG. Is obtained as a moving distance L1 to the steering point 45.

  In step S5, it is determined whether or not the speed adjustment described later is being performed by evaluating whether or not the variable “mode” is zero. If the variable “mode” is not 0, the speed adjustment is already in progress, and the process proceeds to step S9.

In step S6 corresponding to the start determination means 106, it is determined whether or not it is time to start speed adjustment. When the following conditional expression is satisfied, it is determined that the speed adjustment start time is reached.
L1 / V ≦ T
Here, V represents the speed of the vehicle 2. T represents a set time serving as a determination threshold, and is set to a predetermined value (for example, 1 second). The left side of the conditional expression indicates the expected arrival time to the steering point 45, and when the expected arrival time falls below the set time T, it is determined that the speed adjustment start time is reached. By determining in this way, when the speed of the vehicle 2 is high, the speed adjustment can be started early to eliminate the delay in the speed adjustment. For example, the speed adjustment can be started at a timing suitable for the speed of the vehicle 2. Further, the speed adjustment can be started in a state where the set time T is secured until the steering point 45.

  Steps S7 and S8 are processing when it is determined that the timing for starting the speed adjustment is reached.

  In step S7, 1 is substituted into the variable “mode”, and the fact that the speed adjustment is being performed is stored.

  In step S8, the driver is notified that it is time to start steering. Specifically, the CPU 21 outputs “turn the steering wheel all the way to the right” from the speaker 18 via the voice synthesis circuit 25 to notify the driver that it is time to start steering. The driver who has received the notification starts to steer the steering wheel 12 up to the vicinity of the substantially maximum steering angle on the right side in a state where the vehicle 2 is not stopped according to the voice guidance.

  While the driver starts steering, the CPU 21 performs the processes of steps S9 and S10 corresponding to the speed adjusting means 107.

  In step S9, the speed of the vehicle 2 is adjusted. Specifically, the CPU 21 sets a predetermined target vehicle speed Vt (for example, 1 km / h) as an upper limit vehicle speed, and performs speed adjustment (feedback control) so that the speed detected by the speed detection unit 104 is equal to or lower than the target vehicle speed Vt. . Here, the target vehicle speed Vt is set to a vehicle speed such that the parking accuracy is not more than a predetermined value even if the driver steers during traveling.

  In step S10, when the steering angle of the steering wheel 12 substantially coincides with the substantially maximum steering angle on the right side, that is, when the steering operation by the driver is finished, it is determined that it is time to finish the speed adjustment, and the speed adjustment is performed. The process ends (step S11).

4). Rightward turning backward: Thereafter, the driver is guided to the parking target position by continuing the backward movement of the vehicle 2 while keeping the steering wheel 12 in accordance with the voice guidance. A detailed description of the rightward turn-back is also disclosed in Japanese Patent Laid-Open No. 2001-334899, and is omitted here.

  As can be seen from the present embodiment, “when steering” in the present invention means both the situation during the steering operation by the driver and the situation before the steering operation by the driver.

  In the above description, the case of parallel parking in the left parking frame S as viewed from the driver has been described, but it goes without saying that the same processing is also performed in the case of parallel parking in the right parking frame. .

  As described above in detail, according to the present embodiment, the vehicle speed 2 is suitably adjusted by the speed adjusting means 107 during steering by the driver, so that the amount of movement during the steering can be reduced even if steering is performed without stopping. Since it is short, there is no error in the parking route 40, and steering after stopping is unnecessary, so that the parking operation can be completed efficiently while maintaining good parking accuracy.

  Further, when the vehicle is stopped and steered, tires may be unevenly worn, but this problem can be solved according to the present embodiment.

  In addition, embodiment of this invention is not limited to this embodiment, You may change as follows. Even if such a change is added, the same effect as the present embodiment can be obtained.

  The relative position detection means 103 of the present embodiment is configured by means for detecting the rotational angular velocity and steering angle detection means 105 for detecting the steering angle of the steering device for obtaining the turning radius of the vehicle 2. You may comprise using the wheel speed sensor which detects this rotational speed. Moreover, you may comprise the relative position detection means 103 by measuring the position of the vehicle 2 using a satellite-based positioning system (GPS system).

  Although the present embodiment has been described in the case of parallel parking, the same effect can be obtained even in the case of parallel parking. When parallel parking is performed between the vehicles 2c and 2d as shown in FIG. 14, the parking path 40 is a straight line (a line segment between the approximate middle point O5 of the central axis of the rear wheel of the vehicle 2 shown in FIG. 14 and the steering point 45). ) And a circular arc from the substantially middle point O of the center axis of the rear wheel of the vehicle 2 to the steering point 45 (the arc corresponding to the angle O2 of the center O4 and the radius R3). In this case, the present invention can be applied because the driver needs to steer for turning after turning the steering wheel straight. The moving distance L1 to the steering point 45 in this case is between the steering point 45 and the substantially intermediate point O5 of the center axis of the rear wheel of the vehicle 2 that is moving backward along the parking path 40 as shown in FIG. Straight line distance. In this case, the relative position detecting means 103 may be constituted by a wheel speed sensor that detects the rotational speed of each wheel that can detect the moving distance when traveling straight, and the moving distance L1 to the steering point 45 may be obtained.

  Furthermore, the present invention is not limited to a backward parking operation such as parallel parking or parallel parking, and can be applied to, for example, a forward parking operation or a vehicle approaching the road shoulder. is there.

  In the start determination unit 106 of the present embodiment, the speed adjustment start timing is determined regardless of the driver's steering status, but the speed adjustment start timing may be set in accordance with the driver's steering start. In this case, when it is determined that the driver has started steering based on the steering angle information from the steering angle detection means 105, the speed adjustment start time is determined. By taking such a configuration, the driver who has received the notification that it is the timing to start steering, even if the steering is started after checking the surrounding safety, the speed adjustment is started accordingly, An effect that the driver does not feel uncomfortable can be achieved.

  The start determination unit 106 of the present embodiment determines the speed adjustment start time based on the parking route 40 set by the route setting unit 101 and the relative position detected by the relative position detection unit 103. It is not limited. This is based on the idea that the time when the vehicle 2 arrives at a predetermined position on the parking route 40 is the start time of the speed adjustment. For example, the speed adjustment can be started from a predetermined distance before a predetermined steering point (for example, 5 m before).

In the start determination means 106 of the present embodiment, the set time T is set to a predetermined fixed value, but may be a value obtained by calculation by the CPU 21. For example, you may obtain | require like the following formula | equation.
T = dθ / ωs
Here, dθ is a steering amount required at the time of steering calculated based on the parking route 40 (hereinafter referred to as “necessary steering amount dθ”). In the case of the parking route 40 in FIG. This is the steering amount necessary to change from the steering angle of the circle to the steering angle of the second turning circle. Further, ωs is a predetermined average steering angular velocity of the driver. As a result, the time required to perform the required steering amount dθ is set as the set time T, and speed adjustment according to the required steering amount at that time can be started. In the above description, the steering angular velocity ωs is set to a predetermined average steering angular velocity of the driver. For example, a memory of past steering angular velocities may be used as the steering angular velocity ωs. As a result, the driver can start adjusting the speed of the vehicle 2 at a timing according to the speed of the steering operation.

In the start determination means 106 of this embodiment, the start time of the speed adjustment is
L1 / V ≦ T
However, instead of the current speed V of the vehicle 2, a predetermined fixed value or a value calculated by the CPU 21 may be used in the conditional expression. For example, by using the predetermined target vehicle speed Vt in the present embodiment, the speed adjustment of the vehicle 2 can be started at a timing that takes into account the actual speed adjustment.

  In the speed adjusting means 107 of the present embodiment, the speed of the vehicle 2 is adjusted by the deceleration operation by the automatic brake device, but is not limited to this. For example, the speed of the vehicle 2 may be adjusted by controlling at least one of the throttle device and the automatic brake device.

  In the process of step S9 of FIG. 13 in the speed adjusting means 107 of the present embodiment, the speed of the vehicle 2 is adjusted so that the speed of the vehicle 2 detected by the speed detecting means 104 becomes the target vehicle speed Vt. It is not a thing. For example, without being based on the speed detection means 104, even if the driver steers while driving, the automatic brake device is operated according to a predetermined output value so that the parking accuracy becomes a predetermined value or less to adjust the speed. You may comprise as follows.

In the process of step S9 in FIG. 13 in the speed adjusting unit 107 of the present embodiment, the target vehicle speed Vt is set to a predetermined vehicle speed, but a value calculated by the CPU 21 may be used. For example, the target vehicle speed Vt is
Vt = L1 / (dθ / ωs)
And set. Further, the CPU 21 controls the automatic brake device 27 so that the speed of the vehicle 2 detected by the vehicle speed sensor 19 becomes the target vehicle speed Vt. By setting the target vehicle speed Vt with this calculation method, the speed is adjusted so that the steering can be terminated when the vehicle 2 substantially reaches the steering point 45, so that parking can be performed with higher accuracy. become.

  In the process of step S9 of FIG. 13 in the speed adjusting unit 107 of the present embodiment, the feedback control is performed with the target vehicle speed Vt as the upper limit value. However, the feedback control may be performed so as to follow the target vehicle speed Vt. At this time, in order to complete the parking operation more efficiently, the target vehicle speed Vt may be set so that the target vehicle speed Vt> 0, and the speed may be adjusted so as not to stop the vehicle during steering by the driver. .

  In the process of step S10 of FIG. 13 in the speed adjusting unit 107 of the present embodiment, the speed is adjusted when the steering angle of the steering wheel 12 substantially matches the substantially maximum steering angle on the right side, that is, when the steering operation by the driver is finished. Although it is determined that it is time to finish the adjustment, the present invention is not limited to this. For example, it may be determined that the vehicle 2 has arrived at a predetermined position on the parking route 40 or that it is time to finish the speed adjustment after a predetermined time has elapsed.

  In this embodiment, the notification of the timing for starting the steering described in step S8 of FIG. 13 is set to the same timing as the start timing of the speed adjustment of the start determination means 106, but at a timing different from the start timing of the speed adjustment. You may set the timing which starts steering.

It is the schematic which shows the vehicle carrying the parking assistance apparatus 1 in one Embodiment of this invention. It is a system configuration figure of parking assistance device 1 in the embodiment. It is a functional block diagram of the parking assistance apparatus 1 in the embodiment. It is a side view which shows the attachment state of the camera of the embodiment. It is a top view which shows the detection range of the camera of the embodiment. It is a figure which shows the display area of the camera and monitor screen of the embodiment. It is a top view which shows the parking expected position of a vehicle when carrying out parallel parking. FIG. 8 is a plan view showing a state when the vehicle is moved backward while maintaining the steering after setting the parking target position from the state of FIG. 7. It is a top view which shows the state of the vehicle when carrying out parallel parking in a parking frame. It is a step figure which shows the processing mode of CPU corresponding to the state of a vehicle. It is a step figure which shows the processing mode of CPU corresponding to the state of a vehicle. It is a step figure which shows the processing mode of CPU corresponding to the state of a vehicle. It is a flowchart for demonstrating the process of CPU21. It is a top view which shows a state when a vehicle is made to reverse | retreat, setting a parking target position when carrying out parallel parking, keeping a steering in a straight ahead state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Parking assistance apparatus 2 Vehicle 11 Camera 12 Steering wheel 13 Steering angle sensor (Relative position detection means, Steering angle detection means)
16 Yaw rate sensor (relative position detection means)
17 Monitor screen 18 Speaker 19 Vehicle speed sensor (speed detection means)
20 controller 21 CPU (route setting means, start determination means, speed adjustment means)
25 Speech synthesis circuit 27 Automatic brake device (speed adjusting means)
40 parking route 45 steering point 101 route setting means 102 relative position detecting means 103 steering angle detecting means 104 speed detecting means 105 start determining means 106 speed adjusting means 107 automatic steering means

Claims (1)

Route setting means for setting a parking route for moving the vehicle to the parking target position;
Route determination means for determining whether the parking route set by the route setting means is a parking route that requires a steering operation by a driver in the middle of the parking route;
A relative position detecting means for detecting a relative position of the vehicle with respect to the parking target position;
When the driver moves the vehicle to a parking target position according to the parking route determined that the route determination means needs the steering operation, the driver does not stop the vehicle when performing the steering operation. Speed adjusting means for adjusting the speed of the vehicle by decelerating;
Informing means for informing the driver of timing for starting the steering operation by decelerating the vehicle by the speed adjusting means before the driver performs the steering operation ;
Rudder angle detecting means for detecting the rudder angle of the steering device;
With
The speed adjusting means starts the speed adjustment when the vehicle reaches a predetermined position on the parking path based on the parking path and the relative position detected by the relative position detecting means, and detects the steering angle. The parking assist device, wherein the speed adjustment is terminated when a steering angle of the steering device detected by the means coincides with a predetermined steering angle.

Images