JP2018039294A - Parking support method and parking support apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking support method to enable an easy search for an empty parking spot when traveling in a car park while searching for the empty parking spot.SOLUTION: A parking support method, for use in supporting an empty parking spot searching travel for a vehicle itself S using a parking support ECU incorporated in the vehicle itself S, includes: detecting a road width W of a travel road R within a car park P when parking at a parking spot; setting, within the travel road R, a parking spot search route α for searching for an empty parking spot during a travel, in accordance with the road width W of the detected travel road R; and guiding the vehicle itself S on the basis of the parking spot search route α.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a parking support method and a parking support device that support traveling when traveling on a traveling path in a parking lot while searching for an empty parking frame when the host vehicle is parked.

  2. Description of the Related Art Conventionally, there is known a parking support method for generating a movement route from a predetermined warehousing position to an empty parking frame for parking the host vehicle and guiding the host vehicle to an empty parking frame (see, for example, Patent Document 1).

JP 2015-74321 A

  By the way, when searching for an empty parking frame that can be parked while traveling on the road in the parking lot, the empty parking frame is generally searched due to the influence of the shooting range of the camera mounted on the vehicle and the sensor range of the radar. The possible range is limited. Therefore, when the travel route in the travel route is inappropriate, it may not be possible to search for an empty parking frame.

  The present invention has been made paying attention to the above problem, and provides a parking support method and a parking support device that can easily search for an empty parking frame when traveling in a parking lot while searching for an empty parking frame. For the purpose.

In order to achieve the above object, the present invention provides a parking support method for assisting in a search for an empty parking frame of a host vehicle by a parking controller mounted on the host vehicle, wherein the road width detection step and the parking frame search route setting step And a vehicle guidance step.
In the road width detection step, when entering the empty parking frame, the road width of the traveling road in the parking lot is detected.
In the parking frame search route setting step, a parking frame search route for searching for an empty parking frame during traveling is set in the traveling route according to the width of the traveling route.
In the host vehicle guidance step, the host vehicle is guided based on the parking frame search route.

  As a result, when traveling in a parking lot while searching for an empty parking frame, it is possible to easily search for an empty parking frame.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram illustrating a configuration of a vehicle on which a parking assist device of Example 1 is mounted. It is a block diagram which shows the system configuration | structure of parking assistance ECU of Example 1. FIG. It is explanatory drawing which shows the travel path, road width, and parking frame search path | route when parking a vehicle. It is the 1st explanatory view at the time of estimating the position of the own vehicle based on a parking frame. It is the 2nd explanatory view at the time of estimating the position of the own vehicle based on a parking frame. It is the 3rd explanatory view at the time of estimating the position of the own vehicle based on a parking frame. It is the 1st explanatory view at the time of estimating the position of the own vehicle from own vehicle position information. It is the 2nd explanatory view at the time of estimating the position of the own vehicle from own vehicle position information. It is 1st explanatory drawing at the time of estimating the position of the own vehicle based on the object position in a parking lot. It is the 2nd explanatory view at the time of estimating the position of the own vehicle based on the object position in a parking lot. It is the 1st explanatory view showing the road width detection method of a runway. It is the 2nd explanatory view showing the road width detection method of a runway. It is the 1st explanatory view at the time of detecting the road width of a runway from passage width information. It is the 2nd explanatory view at the time of detecting the road width of a runway from passage width information. It is explanatory drawing which shows the setting position of the parking frame search path | route when the road width of a driving path is wider than a road width threshold value. It is explanatory drawing which shows the setting position of the parking frame search path | route when the road width of a driving path is narrower than a road width threshold value. It is explanatory drawing which shows the straight line fitted to the parking frame, and the parking frame search path | route. It is explanatory drawing which shows the lateral deviation and yaw angle deviation of a vehicle estimated position and a parking route or a parking frame search route. It is explanatory drawing which shows the lateral deviation of a vehicle estimated position and a parking route or a parking frame search route when using a gaze point distance. It is a flowchart which shows the parking assistance processing procedure which parking assistance ECU of Example 1 performs. It is a flowchart which shows the empty parking frame search route setting process procedure which parking assistance ECU of Example 1 performs. It is the 1st explanatory view showing the subject at the time of empty parking frame search. It is the 2nd explanatory view showing the subject at the time of empty parking frame search. It is the 1st explanatory view showing the self-vehicle position at the time of parking support execution. It is 2nd explanatory drawing which shows the own vehicle position at the time of parking assistance execution. It is the 1st explanatory view in the 1st pattern of empty parking frame search. It is the 2nd explanatory view in the 1st pattern of empty parking frame search. It is the 1st explanatory view in the 2nd pattern of empty parking frame search. It is the 2nd explanatory view in the 2nd pattern of empty parking frame search. It is the 3rd explanatory view in the 2nd pattern of empty parking frame search. It is the 1st explanatory view in the 3rd pattern of empty parking frame search. It is the 2nd explanatory view in the 3rd pattern of empty parking frame search. It is the 3rd explanatory view in the 3rd pattern of empty parking frame search. It is the 1st explanatory view in the 4th pattern of empty parking frame search. It is the 2nd explanatory view in the 4th pattern of empty parking frame search. It is the 3rd explanatory view in the 4th pattern of empty parking frame search. It is explanatory drawing which shows the preceding vehicle in driving | running | working road driving | running | working. It is explanatory drawing which shows the oncoming vehicle in driving | running | working path driving | running | working. It is explanatory drawing which shows the other 1st example of the setting method of a parking frame search path | route. It is explanatory drawing which shows the other 2nd example of the setting method of a parking frame search path | route. It is an example of the map which shows the relationship between the recognition accuracy of a parking frame, and the distance from the straight line fitted to the parking frame to the parking frame search route. It is explanatory drawing which shows the shift | offset | difference with the true value of a parking frame, and a parking frame recognition position. It is an example of the error map which shows the deviation | shift amount of the true value of a parking frame with respect to the distance from the own vehicle to a parking frame, and a parking frame recognition position.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the parking assistance method and parking assistance apparatus of this invention is demonstrated based on Example 1 shown on drawing.

Example 1
First, the configuration of the parking support apparatus according to the first embodiment will be described by dividing it into “vehicle configuration”, “system configuration of parking support ECU”, “parking support processing procedure”, and “empty parking frame search route setting processing procedure”.

[Vehicle configuration]
FIG. 1 is a system configuration diagram illustrating a configuration of a vehicle on which the parking assist device according to the first embodiment is mounted. Hereinafter, based on FIG. 1, the structure of the vehicle by which the parking assistance apparatus of Example 1 is mounted is demonstrated.

  The parking assist device according to the first embodiment includes a parking assist ECU (Electiric Control Unit, parking controller) 100 mounted on the vehicle S. Here, as shown in FIG. 1, the vehicle S is a four-wheeled vehicle in which the engine 10 is a driving source and the wheel speed sensors 21, 22, 23, and 24 are provided on the wheels 11, 12, 13, and 14, respectively. It is. The wheel speed sensors 21 to 24 transmit wheel speed signals to the parking assist ECU 100. Further, the camera 25, 26, and the camera 25, 26, respectively, are located at the front end center position of the vehicle S, the lower left end position of the left side mirror 15L, the lower right end position of the right side mirror 15R, and the rear end center position of the vehicle S. 24 and 28 are provided. The cameras 25 to 28 transmit the captured image signal around the vehicle to the parking assist ECU 100.

  Here, the engine 10 is a four-cycle / spark ignition type / multi-cylinder / gasoline fuel / internal combustion engine. The engine 10 is provided with an engine actuator 31. The engine actuator 31 includes a fuel injection valve, an ignition device, and a throttle actuator that changes the throttle valve opening, and is an actuator that performs operations necessary for operating the engine 10. The engine actuator 31 receives a control signal from the parking assist ECU 100 and outputs a driving force according to the control signal from the engine 10.

  The steering wheel 16 is rotated (steered) by the driver to steer the vehicle S. Here, when the rotation of the steering wheel 16 is transmitted to the pinion constituting the steering mechanism 17 through the steering shaft and the connecting shaft, the rack reciprocates due to the rotation of the pinion, and the reciprocating movement of the rack passes through the tie rods. The vehicle S is steered by being transmitted to. The steering mechanism 17 is provided with a steering actuator 32. The steering actuator 32 is an actuator that applies a steering force to the steering mechanism 17 and causes the steering mechanism 17 to perform turning according to a control signal from the parking assist ECU 100. Further, the steering angle of the steering wheel 16 is detected by a steering angle sensor 29. The steering angle sensor 29 transmits a steering angle signal to the parking assist ECU 100.

  The range position sensor 30 is a so-called inhibitor switch that detects a range position (P (parking), R (reverse), D (drive), M (manual mode), etc.)) selected by a select lever (not shown). A range position selection signal is transmitted to the parking assist ECU 100. The select lever is provided with a range actuator 33. The range actuator 33 is an actuator that applies a lever driving force to the select lever and selects a range position according to a control signal from the parking assist ECU 100.

  Further, the vehicle S is provided with a brake actuator 34. The brake actuator 34 is an actuator that opens and closes a pressure increase control valve and a pressure reduction control valve provided in the brake hydraulic circuit, and outputs a braking force according to a control signal from the parking assist ECU 100.

  An on-vehicle monitor 18 using a liquid crystal display device or the like is provided on the center console (not shown) of the vehicle S. The parking assist ECU 100 displays on the in-vehicle monitor 18 images of the vehicle surroundings captured by the cameras 25 to 28. The parking route set by the parking assist ECU 100 is displayed on the in-vehicle monitor 18. The in-vehicle monitor 18 may be shared with a display unit of a navigation device (not shown).

A search mode switch 19 and an aisle travel mode switch 20 are provided around the driver's seat of the vehicle S. The search mode switch 19 is a switch that inputs an ON signal to the driving assistance ECU 100 when it is turned ON, and searches for an empty parking frame. In the own vehicle S, if an empty parking frame is detected, the parking assistance process mentioned later is implemented. In the parking support process in the first embodiment, the self-vehicle S is operated by the control signal from the parking support ECU 100 regardless of whether the driver is seated in the driver's seat, and the fully automatic driving is performed.
The aisle travel mode switch 20 is a switch that, when turned ON, inputs an ON signal to the driving assistance ECU 100 and executes an empty parking frame search route setting process described later. In the own vehicle S, when the parking frame search route is set, a parking frame search support process described later is performed. In the parking frame search support process of the first embodiment, the self-vehicle S is operated by a control signal from the parking support ECU 100 regardless of whether the driver is seated on the driver's seat, and a fully automatic driving is performed.

[System configuration of parking assist ECU]
FIG. 2 is a block diagram illustrating a system configuration of the parking assistance ECU according to the first embodiment. Hereinafter, based on FIG. 2, the system configuration | structure of parking assistance ECU with which the parking assistance apparatus of Example 1 is provided is demonstrated.

  As shown in FIG. 2, the parking assist ECU 100 according to the first embodiment includes wheel speed sensors 21 to 24, cameras 25 to 28, a steering angle sensor 29, a range position sensor 30, a search mode switch 19, and a passage. Predetermined input information is input from the travel mode switch 20.

  In the parking assist ECU 100, when the host vehicle S is stored in the target parking frame M, when an ON signal is input from the search mode switch 19, various sensors such as the wheel speed sensors 21 to 24 and the cameras 25 to 28 are used. An empty parking frame is detected based on predetermined input information input from.

Here, when an empty parking frame cannot be detected and an ON signal is input from the aisle travel mode switch 20, the parking assist ECU 100 firstly sets the position O ₁ of the host vehicle S in the parking lot P shown in FIG. And the road width W of the travel path R in the parking lot P is detected. When the road width W of the travel path R is detected, a parking frame search path α for searching for an empty parking frame during the travel of the travel path R is set in the travel path R according to the road width W of the travel path R. Furthermore, if the parking frame search route α is set, the vehicle S is guided along the parking frame search route α to assist in searching for an empty parking frame.
That is, when the parking assist ECU 100 sets the parking frame search route α, it outputs control signals to the engine actuator 31, the steering actuator 32, the range actuator 33, and the brake actuator 34, and the host vehicle S becomes the parking frame search route α. Drive along the road and search for an empty parking space appropriately.

In addition, when the parking assist ECU 100 detects a parking frame (empty parking frame) that can be parked, the parking assist ECU 100 sets the position of the target parking frame M and parks the current vehicle S from the current position O ₁ to the target parking frame M. Set the route. Then, control signals are output to the engine actuator 31, the steering actuator 32, the range actuator 33, and the brake actuator 34, so that the host vehicle S travels along the parking route and is parked in the target parking frame M. If the position of the target parking frame M is updated while traveling along the parking route, that is, during the parking operation, the vehicle is corrected while correcting the parking route according to the updated position of the target parking frame M. S is induced. Further, the parking assist ECU 100 outputs a display signal for causing the in-vehicle monitor 18 to display the parking route search route α and the parking route.

  As shown in FIG. 2, the parking assist ECU 100 according to the first embodiment includes a parking frame recognition unit 101, a target parking frame setting unit 102, a parking start position setting unit 103, a parking route generation unit 104, a parking lot Frame search route setting unit 105, switch 106, route follow-up control unit 107, target speed generation unit 108, parking route position estimation unit 109, search route position estimation unit 110, switch 111, A steering angle control unit 112 and a speed control unit 113 are provided.

  In the parking frame recognition unit 101, when an ON signal is input from the search mode switch 19, a parking frame is detected by analyzing a bird's-eye view image generated by bird's-eye conversion of the image signals detected by the cameras 25 to 28. The parking frame position information is output. In addition, the parking frame recognition unit 101 determines whether there is a parking frame (empty parking frame) in which the host vehicle S can be parked, and outputs a “parking signal” when it is determined that there is an empty parking frame. When it is determined that there is no free parking frame, a “parking frame search signal” is output. The parking frame position information, “parking signal”, and “parking frame search signal” are input to the target parking frame setting unit 102, the parking frame search route setting unit 105, and the in-search route position estimation unit 110, respectively.

  In the target parking frame setting unit 102, when the “parking signal” and the parking frame position information are input from the parking frame recognition unit 101, an appropriate area is detected from the detected parking frames based on the parking frame position information. Set as M. The target parking frame setting unit 101 outputs a display signal for displaying the set position information of the target parking frame M on the vehicle-mounted monitor 18, and the vehicle-mounted monitor 18 superimposes the image on the images obtained by the cameras 25 to 28. The target parking frame M may be displayed. The target parking frame setting unit 102 sets a target parking position inside the set target parking frame M. This target parking position is the center position of the rear wheel axle when the host vehicle S is parked.

  In the parking start position setting unit 103, when the target parking frame setting unit 102 sets the target parking frame M, the parking start position setting unit 103 sets the parking start position based on the position and posture (traveling direction) of the host vehicle S at that time. Here, “setting the parking start position” means that the position of the host vehicle S (parking start position) at the time when the target parking frame M is set is the origin of the XY coordinate system, and the posture at this time (the host vehicle) The XY coordinate system is set with the S traveling direction) as the Y direction. The position of the host vehicle S is based on the center position in the left-right direction of the rear wheel axle. The parking assist ECU 100 according to the first embodiment generates the parking frame search route α and the parking route using the XY coordinate system set by the parking start position setting unit 103.

  In the parking route generation unit 104, based on the position information of the target parking frame M set by the target parking frame setting unit 102 and the position information of the parking start position of the host vehicle S set by the parking start position setting unit 103. To generate a parking route.

  Here, the parking route is set by combining one or more of an arc, a clothoid curve, and a straight line. The parking route is assumed to be a straight line → clothoid curve → constant curvature arc → clothoid curve between the parking start position and the target parking position, for example, and a map showing the relationship between the curvature and distance of the preset route. Can be based on.

In the parking frame search route setting unit 105, when the “parking frame search signal” and the parking frame position information are input from the parking frame recognition unit 101 and the ON signal from the aisle travel mode switch 20 is input, A position O ₁ of the host vehicle S in the parking lot P is estimated. When the position O ₁ of the host vehicle S is estimated, the road width W of the travel path R in the parking lot P is detected. When the road width W of the travel path R is detected, a parking frame search path α for searching for a parking frame during travel is set in the travel path R according to the detected road width W.
The “parking frame search path α” means that when the host vehicle S travels the travel path R, the parking frame existing along the travel path R is within the shooting range of the cameras 25 to 28 mounted on the host vehicle S. It is a route that can be run while entering. The “traveling path R” is a passage set in the parking lot P, and the position of the traveling path R is an overhead view image generated by performing an overhead conversion of the image signals detected by the cameras 25 to 28. It is detected by analyzing or receiving the road information from the base station A installed in the parking lot P.

Here, the position estimation of the host vehicle S in the parking lot P is performed by the following method, for example.
-The position of the own vehicle S is estimated based on parking frame position information.
-The own vehicle position information is received and the position of the own vehicle S is estimated.
The position of the host vehicle S is estimated based on the positions of objects such as walls and other vehicles existing in the parking lot P.

That is, as shown in FIG. 4, the lateral position of the host vehicle S with respect to the parking frame K detected based on the parking frame position information input from the parking frame recognition unit 101 is calculated, and based on the calculated lateral position information. The current position O ₁ of the host vehicle S is estimated.

Further, as shown in FIG. 5, when a plurality of parking frames K are detected based on the parking frame position information input from the parking frame recognition unit 101, an approximate function is shown for the positions of the plurality of parking frames K. fitting a curve (straight line) K ₁ which calculates the lateral position of the vehicle S for the fitted curve (straight line) K _1. Then, based on the calculated lateral position information, the position O ₁ of the host vehicle S is estimated.
In addition, when fitting to a linear function, it can obtain | require by following formula (1). Further, the approximate function does not need to be a linear function. The coefficients A and B are obtained by the following formulas (2) and (3) by the least square method.
Where Cov (X, Y): covariance of X, Y
σX: dispersion of X
σY: Y dispersion
μX: Average of X
μY: Average of Y.

Note that when fitting the curve (straight line) K ₁ represented by the approximation function for a plurality of parking frame K, when the detection accuracy of the parking frame K is low, first, one by one sequentially fitting possible parking space And the correlation coefficient σ is obtained from the following equation (4). Then, the highest X, fitting the curve (straight line) K ₁ represented by the approximation function by a combination of Y Correlation coefficient sigma (see Fig. 6).
Where Cov (X, Y): covariance of X, Y
σX: dispersion of X
σY: Y dispersion

Further, in the case of estimating the current position O ₁ of the vehicle S from the vehicle position information, as shown in FIG. 7A, detects the position O ₁ of the vehicle S by the installed base station X to the parking lot P The vehicle position information is received from the base station X. In addition, as shown to FIG. 7B, you may detect the own vehicle position information from the relative positional relationship with the other vehicle (parked vehicle B) already parked in the parking frame K. FIG.

Furthermore, in the case of estimating the current position O ₁ of the own vehicle S based on the wall C present in parking P, as shown in FIG. 8A, measure the distance C ₁ between the wall C and the vehicle S Then, the position O ₁ of the host vehicle S is estimated from the measured distance information with respect to the wall C. Further, when estimating the position O ₁ of the own vehicle S based on the parking space K already parked other vehicles in (parked vehicle B), as shown in FIG. 8B, the parked vehicle B and the subject vehicle S the distance B ₁ is measured, and to estimate the position O ₁ of the vehicle S from the distance information between the measured parked vehicle B.

And the detection of the width W of the traveling path R in the parking lot P is implemented by the following method, for example.
The road width W of the travel path R is detected based on the parking frame position information.
The passage width information is received and the road width W of the traveling path R is detected.

  That is, as shown in FIG. 9A, when the parking frame K is detected only on one side of the host vehicle S, the parking frame K sandwiches the host vehicle S from the end of the detected parking frame K. The distance to the object on the opposite side (in this case, the wall C) is the road width W of the travel path R.

  Further, as shown in FIG. 9B, when the parking frames A and B are detected on both sides of the own vehicle S, the relative distance between the left and right parking frames A and B (the parking space existing on the left side of the own vehicle S). The distance from the end of the frame A on the own vehicle S side to the end of the parking frame B on the right side of the own vehicle S on the own vehicle S side is defined as the road width W of the travel path R.

When the road width W of the travel path R is detected from the path width information, as shown in FIG. 10A, the base station X installed in the parking lot P is previously provided with the passage width information of the travel path R in the parking lot P. And the passage width information is received from this base station X. When other vehicle (not shown) stores passage width information, passage width information may be received from this other vehicle.
Further, as shown in FIG. 10B, the passage width information of the traveling path R in the parking lot P included in the parking lot information recorded in the database 31 based on the position information of the own vehicle S included in the car navigation system 30. And the passage width information may be read from the database 31.

Further, when the road width W of the travel path R is wider than a predetermined road width threshold Th set in advance, the parking frame search path α is set along a position that is biased to the left or right of the center position β in the width direction of the travel path R. (See FIG. 11A). When the road width W of the travel path R is equal to or less than a predetermined road width threshold Th set in advance, the parking frame search path α in the travel path R is determined along the center position β in the width direction of the travel path R. α is set (see FIG. 11B).
Here, the “road width threshold Th” is a value obtained by adding a passing margin distance (gap size required when vehicles pass each other) to twice the vehicle body width of the own vehicle S, and a parking frame of the own vehicle S. the width dimension of the search range S _1, a value obtained by subtracting the recognition margin distance (range dimension of recognition error), and any smaller value of the. The “parking frame search range” is a range that can be captured by the cameras 25 to 28 mounted on the host vehicle S.

And the setting of the parking frame search path | route alpha along the position which left-right shifted rather than the center position (beta) of the width direction of the driving path R is implemented with the following methods, for example.
-It is determined whether there is a parking frame on each of the left side and the right side of the travel path R. When it is determined that a parking frame exists only on either the left or right side of the travel path R, an approximation function is fitted to the parking frame. Then, the parking frame search route α is set along a position separated from the straight line indicated by the fitted approximation function by a predetermined distance set in advance. That is, the parking frame search route α is set at a position close to the parking frame existing along either the left or right side of the travel route R.
-It is determined whether there is a parking frame on each of the left side and the right side of the travel path R. When it is determined that there is a parking frame on either side of the travel path R, an approximate function is fitted to the parking frame. Then, the parking frame search route α is set along a position that is separated by a predetermined distance from a straight line indicated by an approximate function that is present at a position closer to the position of the host vehicle S. That is, the parking frame search route α is set at a position close to the parking frame existing along either the left or right side of the travel route R.
-It is determined whether there is a parking frame on each of the left side and the right side of the travel path R. If it is determined that there is no parking frame on either side of the road R, the parking frame search path α is set along a position a predetermined distance to the left from the center position β in the width direction of the road R. To do. That is, when there is no parking frame along the travel route R, the parking frame search route α is set based on a predetermined travel rule.

Incidentally, as shown in FIG. 12, a parking frame searched route alpha, the distance L between the straight line K ₁ represented by the approximation function was fitted to the parking frame K can be arbitrarily set, for example, of the vehicle S Set the distance to half the parking frame recognition range. Also, the linear distance from K ₁ to the parking space search path alpha L is constant, is set in parallel to the straight line K ₁ and the parking space searched route alpha.

  The switch 106 is a switching circuit that switches between the parking support mode and the empty parking frame search support mode. When the parking route generated by the parking route generation unit 104 is input, it is determined that the parking support mode is in the parking support mode. The route information of the route is input to the route tracking control unit 107. On the other hand, when the parking frame search route α set by the parking frame search route setting unit 105 is input to the switch 106, it is determined that the parking frame search route α is in the empty parking frame search support mode, and the route information of the parking frame search route α is displayed. Input to the route following control unit 107.

When in the parking assistance mode, the route following control unit 107 firstly shows the route information of the parking route generated by the parking route generation unit 104 and the current position information of the host vehicle S input from the in-parking route position estimation unit 109. And a target steering angle for causing the host vehicle S to travel following the parking route.
In the parking route position estimation unit 109, the parking start position set by the parking start position setting unit 103 based on the wheel speed information from the wheel speed sensors 21 to 24 and the steering angle information from the steering angle sensor 29. The current position and posture (traveling direction) of the vehicle S existing on the XY coordinates that have moved from the above are estimated. The estimated current position information in the parking route of the host vehicle S is input to the route following control unit 107 via the switch 111.

On the other hand, in the route tracking control unit 107, in the empty parking frame search support mode, first, the route information of the parking frame search route α set by the parking frame search route setting unit 105 and the position estimation unit in the search route Based on the current position information of the host vehicle S input from 110, a target steering angle for causing the host vehicle S to travel following the parking frame search route α is obtained.
The search route position estimation unit 110 estimates the current position and posture (traveling direction) of the host vehicle S with respect to the detected parking frame based on the frame position information input from the parking frame recognition unit 101. The estimated current position information of the host vehicle S in the parking frame search route α is input to the route following control unit 107 via the switch 111.

  Here, the switch 111 is a switching circuit for switching between the parking support mode and the empty parking frame search support mode, and vehicle position information in the parking route estimated by the in-parking route position estimation unit 109 is input. When the vehicle is in the parking assistance mode, the vehicle position information in the parking route is input to the route follow-up control unit 107. On the other hand, when the vehicle position information in the parking frame search route α estimated by the search route position estimation unit 110 is input to the switch 106, it is determined that the empty parking frame search support mode is set, and the parking frame search is performed. The vehicle position information in the route α is input to the route following control unit 107.

The target steering angle can be calculated by the following equation (5).
Where K _str-ρ = coefficient
ρ _traj = _{curvature of} parking route or parking frame search route α.

Next, after setting the target steering angle, the route tracking control unit 107 sets the target according to the lateral deviation between the current position (estimated value) of the host vehicle S shown in FIG. 13A and the parking route or the parking frame search route α. The correction amount of the steering angle is calculated from the following equation (6).
Where K _{FB_ydiff} = lateral deviation feedback gain
y _diff = lateral deviation from parking path or parking frame search path α.

The correction amount of the target steering angle is as follows according to the yaw angle deviation between the yaw angle at the current position (estimated value) of the host vehicle S shown in FIG. 13A and the yaw angle of the parking route or the parking frame search route α. You may calculate from Formula (7).
Where K _{FB_yawdiff} = Yaw angle deviation feedback gain
yaw _diff = Yaw angle deviation with respect to parking route or parking frame search route α.
Further, the correction amount of the target steering angle is set such that a gazing point distance is set on the front side in the traveling direction of the vehicle S shown in FIG. Depending on the lateral deviation from α, it may be calculated from the following equation (8).
Where K _{FB_ydiff} = lateral deviation feedback gain
y _diff = lateral deviation from the parking route or the parking frame search route α at the forward gaze distance
It is.

  Information about the target steering angle and the target steering angle correction amount obtained by the route following control unit 107 is input to the steering angle control unit 112. The steering angle control unit 112 outputs a control signal for causing the actual steering angle of the host vehicle S to follow the input target steering angle to the steering actuator 32. Note that the steering angle of the host vehicle S is detected by the steering angle sensor 29, and feedback control is performed.

  The target speed control unit 108 sets a vehicle speed set in advance according to the curvature of the route as the target speed based on the route information of the parking route or the route information of the parking frame search route α input via the switch 106. . Information on the target speed set by the target speed control unit 108 is input to the speed control unit 113. The speed control unit 113 outputs a control signal for causing the actual speed of the host vehicle S to follow the input target speed to the engine actuator 31 and the brake actuator 34. Note that the speed of the host vehicle S is detected by the wheel speed sensors 21 to 24, and feedback control is performed.

  Further, when the parking assist ECU 100 determines that the vehicle S has reached the return position based on the current position (estimated value) of the vehicle S and the parking route or the parking frame search route α, a forward / reverse switching signal is sent to the range actuator 33. And the traveling direction of the host vehicle S is switched.

[Parking assistance procedure]
Next, the parking assistance processing procedure in Example 1 is demonstrated with reference to the flowchart shown in FIG.

In step S101, it is determined whether or not the search mode switch 19 has been turned ON. If YES (ON operation is present), the process proceeds to step S102. If NO (no ON operation), parking assistance is unnecessary and the process proceeds to the end.
Here, the ON operation of the search mode switch 19 is determined by the ON operation signal input from the search mode switch 19.

In step S102, following the determination that the search mode switch 19 is turned on in step S101, the parking frame is detected based on the image signals detected by the cameras 25 to 28, and the vehicle S can be parked. It is determined whether there is a parking frame. If YES (there is an empty parking frame), the process proceeds to step S103. If NO (no vacant parking frame), the process proceeds to step S109.
Here, the presence or absence of an empty parking frame is also determined based on the image signal.

In step S103, following the determination that there is an empty parking frame in step S102, a target parking frame is set and a parking start position is set. Then, a parking route from the parking start position to the target parking frame is generated, and the process proceeds to step S104.
Here, the target parking frame is set based on the image signal detected by the cameras 25 to 28. The parking start position is set by setting the position of the host vehicle S (parking start position) at the time of setting the target parking frame as the origin of the XY coordinate system, and setting the posture at this time (the traveling direction of the host vehicle S) to Y. This is done by setting XY coordinates as directions. Furthermore, the parking route is generated by combining at least one of an arc, a clothoid curve, and a straight line.

In step S104, following the generation of the parking route in step S103, the current position and posture (traveling direction) in the parking route of the host vehicle S are estimated, and the process proceeds to step S105.
Here, the current position of the host vehicle S is estimated based on the wheel speed information from the wheel speed sensors 21 to 24 and the steering angle information from the steering angle sensor 29.

In step S105, following the vehicle position estimation in step S104, a target steering angle for guiding the host vehicle S from the parking start position to the target parking frame is set according to the curvature of the parking route generated in step S103. The process proceeds to step S106.
Here, the setting of the target steering angle is performed based on the above equation (5). In addition, the target steering angle is corrected as appropriate based on the target steering angle correction amount calculated based on Equation (6), Equation (7), Equation (8), and the like.

In step S106, following the setting of the target steering angle in step S105, a target speed for guiding the host vehicle S from the parking start position to the target parking frame is set according to the curvature of the parking route generated in step S103. Then, the process proceeds to step S107.
Here, the target speed is set in advance according to the curvature of the route.

In step S107, following the setting of the target speed in step S106, the host vehicle S is controlled while controlling the steering angle and speed of the host vehicle S so that the travel route of the host vehicle S follows the parking route generated in step S103. To go to step S108.
Here, in order to follow the travel route of the host vehicle S to the parking route, first, the control signal for selecting the D (drive) range is output to the range actuator 33, and the D lever is selected by the select lever. To drive the host vehicle S. Then, a control signal for causing the speed of the host vehicle S to follow the target speed is output to the engine actuator 31 and the brake actuator 34, and the host vehicle S is caused to travel at a speed corresponding to the target speed. Further, a control signal corresponding to the target steering angle is output to the steering actuator 32 to cause the host vehicle S to travel along the parking route.

In step S108, it is determined whether or not the host vehicle S is parked in the target parking frame following the execution of following the parking route in step S107. In the case of YES (parking complete), the select lever outputs a control signal for selecting the P (parking) range to the range actuator 33 and proceeds to the end. As a result, the P range is selected by the select lever, and the parking support process ends.
If NO (parking is not completed), the process returns to step S104.

In step S109, following the determination that there is no empty parking frame in step S102, it is determined whether or not the passage travel mode switch 20 has been turned ON. If YES (with ON operation), the process proceeds to step S200. If NO (no ON operation), the setting of the parking frame search route α is unnecessary and the process proceeds to step S102.
Here, the ON operation of the passage travel mode switch 20 is determined by the input of an ON operation signal from the passage travel mode switch 20. If it is determined that the setting of the parking frame search route α is unnecessary and the process returns to step S102, the host vehicle S is driven by the driver's manual operation to search for an empty parking frame.

In step S200, following the determination that the passage travel mode switch 20 is turned on in step S109, an empty parking frame search route setting process described later is executed, and the process proceeds to step S110.
Here, the parking frame search route α is set in the travel route R in the parking lot P by executing the empty parking frame search route setting process.

In step S110 (own vehicle guidance step), the parking frame search route α obtained by executing the empty parking frame search route setting process in step S200 follows the setting, and the current position of the own vehicle S in the parking frame search route α and The posture (traveling direction) is estimated, and the process proceeds to step S111.
Here, the current position of the host vehicle S is estimated based on the wheel speed information from the wheel speed sensors 21 to 24 and the steering angle information from the steering angle sensor 29.

In step S111 (own vehicle guidance step), following the vehicle position estimation in step S110, the host vehicle S is moved along the parking frame search route α in accordance with the curvature of the parking frame search route α set in step S200. A target steering angle for guidance is set, and the process proceeds to step S112.
Here, the setting of the target steering angle is performed based on the above equation (5). In addition, the target steering angle is corrected as appropriate based on the target steering angle correction amount calculated based on Equation (6), Equation (7), Equation (8), and the like.

In step S112 (own vehicle guidance step), following the setting of the target steering angle in step S111, the host vehicle S is changed to this parking frame search route α in accordance with the curvature of the parking frame search route α generated in step S200. A target speed for guiding along is set, and the process proceeds to step S113.
Here, the target speed is set in advance according to the curvature of the route.

In step S113 (own vehicle guidance step), following the setting of the target speed in step S112, the steering angle of the own vehicle S so that the travel route of the own vehicle S follows the parking frame search route α generated in step S200. Then, the host vehicle S is caused to travel while controlling the speed, and the process returns to step S102.
Here, in order to make the travel route of the host vehicle S follow the parking frame search route α, first, the select lever outputs a control signal for selecting the D (drive) range to the range actuator 33, and the select lever outputs the D range. Is selected to drive the host vehicle S. Then, a control signal for causing the speed of the host vehicle S to follow the target speed is output to the engine actuator 31 and the brake actuator 34, and the host vehicle S is caused to travel at a speed corresponding to the target speed. Further, a control signal corresponding to the target steering angle is output to the steering actuator 32 to cause the host vehicle S to travel along the parking frame search route α.

[Free parking frame search route setting processing procedure]
Next, the empty parking frame search route setting process in the first embodiment will be described with reference to a flowchart shown in FIG.

In step S201 (road width detection step), following the determination that there is an ON operation of the passage travel mode switch 20 in step S109 in the parking support process, the host vehicle S is present or in the parking lot P where the vehicle is about to travel. While detecting the travel path R, the width W of the detected travel path R is detected, and it progresses to step S202.
Here, the travel path R and the road width W of the travel path R are detected based on, for example, parking frame position information, or are received and detected.

  In step S202 (parking frame search route setting step), following the detection of the road width of the travel path R and the travel path R in step S201, the detected road width W of the travel path R is based on a preset predetermined road width threshold Th. It is judged whether it is wide. If YES (traveling road width> road width threshold Th), the process proceeds to step S203. If NO (running road width ≦ road width threshold Th), the process proceeds to step S213.

In step S203 (parking frame search route setting step), it is determined whether or not there is a parking frame on the left side of the traveling path R following the determination that the traveling road width is larger than the road width threshold Th in step S202. If YES (there is a parking frame on the left side of the road), the process proceeds to step S204. If NO (no parking frame on the left side of the road), the process proceeds to step S209.
Here, the “left side of the travel path R” is the left side in the traveling direction of the host vehicle S, and is the left side of the host vehicle S when the host vehicle S is in the travel path R.

In step S204 (parking frame search route setting step), following the determination that there is a parking frame on the left side of the travel path in step S203, the first straight line is fitted to the parking frame existing on the left side of the travel path R. Proceed to S205.
Here, a 1st straight line is calculated | required by the linear function shown by above-mentioned Formula (1)-(3).

In step S205 (parking frame search route setting step), following the fitting of the first straight line in step S204, it is determined whether or not there is a parking frame on the right side of the travel route R. If YES (there is a parking frame on the right side of the road), the process proceeds to step S206. If NO (no parking frame on the right side of the road), the process proceeds to step S208.
Here, the “right side of the traveling road R” is the right side of the traveling direction of the host vehicle S, and is the right side of the own vehicle S when the own vehicle S is in the traveling path R.

In step S206 (parking frame search route setting step), following the determination that there is a parking frame on the right side of the road in step S205, the second straight line is fitted to the parking frame existing on the right side of the road R. Proceed to S207.
Here, a 2nd straight line is calculated | required by the linear function shown by above-mentioned Formula (1)-(3).

In step S207 (parking frame search route setting step), following the fitting of the second straight line in step S206, the host vehicle out of the first straight line fitted in step S204 and the second straight line fitted in step S206. The straight line with the shorter distance from S is specified. Then, a parking lot search route α is set along a position separated from the straight line determined to be close to the host vehicle S by a predetermined distance set in advance, and the process proceeds to the end. As a result, the host vehicle S travels in the travel path R at a position near the parking frame to which the straight line determined to be close to the host vehicle S is fitted.
In addition, the distance from the straight line determined to be close to the host vehicle S to the parking lot search route α is arbitrarily set, for example, a distance half the parking frame recognition range of the host vehicle S or the like.

In step S208 (parking frame search route setting step), following the determination that there is no parking frame on the right side of the travel path in step S205, along a position separated by a predetermined distance from the first straight line fitted in step S204. To set a parking lot search route α and proceed to the end. As a result, the host vehicle S travels at a position close to the parking frame existing on the left side of the travel path R to which the first straight line is fitted.
The distance from the first straight line to the parking lot search route α is arbitrarily set, for example, a distance that is half the parking frame recognition range of the host vehicle S.

  In step S209 (parking frame search route setting step), following the determination that there is no parking frame on the left side of the travel path in step S203, it is determined whether or not there is a parking frame on the right side of the travel path R. If YES (there is a parking frame on the right side of the road), the process proceeds to step S210. If NO (no parking frame on the right side of the road), the process proceeds to step S212.

In step S210 (parking frame search route setting step), following the determination that there is a parking frame on the right side of the travel path in step S209, the second straight line is fitted to the parking frame existing on the right side of the travel path R. Proceed to S211.
Here, a 2nd straight line is calculated | required by the linear function shown by above-mentioned Formula (1)-(3).

In step S211 (parking frame search route setting step), following the fitting of the second straight line in step S210, a parking lot search route α is set along a position away from the second straight line by a predetermined distance, Go to the end. As a result, the host vehicle S travels in a position close to the parking frame existing on the right side of the travel path R to which the second straight line is fitted, in the travel path R.
In addition, the distance from the second straight line to the parking lot search route α is arbitrarily set, for example, a distance half the parking frame recognition range of the host vehicle S or the like.

In step S212 (parking frame search route setting step), following the determination that there is no parking frame on the right side of the travel path in step S209, it is determined that there is no parking frame on either the left or right of the travel path R. Here, the parking frame search route α is set based on the travel rule that “the parking lot search route α is set along a position that is a predetermined distance away to the left of the center position β in the width direction of the travel route R”. Set to go to the end. As a result, the host vehicle S travels in the travel path R at a position closer to the left side than the center position β in the width direction.
The “left side of the center position β in the width direction of the travel path R” is the left side of the traveling direction of the host vehicle S. Further, the distance L ₃ from the β widthwise center position of the travel path R to the parking lot searched route α is, for example half the distance or the like of the parking space purview of the vehicle S, arbitrarily set.

  In step S213 (parking frame search route setting step), following the determination that the travel road width ≦ the road width threshold Th in step S202, a parking lot search route α is set along the center position in the width direction of the travel route R, and the end Proceed to As a result, the host vehicle S travels in the middle of the travel path R in the width direction.

Next, the operation will be described.
First, “the problem at the time of searching for an empty parking frame” will be described, and then “the parking frame search support operation” in the parking support method and the parking support device of the first embodiment will be described.

[Problems when searching for an empty parking frame]
In the host vehicle S of the first embodiment, an empty parking frame that can be parked is searched based on the image signals detected by the cameras 25 to 28. Here, the range in which the cameras 25 to 28 can be photographed is determined, and the parking frame search range S ₁ of the host vehicle S is limited by the photographable range of the cameras 25 to 28. In other words, even if there is an empty parking frame, it cannot be detected by the own vehicle S unless it falls within the parking frame search range S _{1 of} the own vehicle S (shootable range of the cameras 25 to 28).

In contrast, traveling along the traveling path R of the wide road width W than the parking space search range S ₁ of the vehicle S, it is possible to search for the vacant parking space in the parking P.
However, in this case, as shown in FIG. 16A, if the host vehicle S travels along the center position β in the width direction of the travel path R, the parking frames A and B existing on the left and right of the travel path R and the parking space detection range S ₁ of the vehicle S there is no overlap. That is, the parking space A present on the left and right of the travel path R, if traveling along a position close to one of the B, a parking space A or parking frame B, the parking space detection range S ₁ of the vehicle S Do not overlap. Therefore, even if an empty parking frame exists, there arises a problem that it cannot be detected properly.

On the other hand, as shown in FIG. 16B, the road width W of the travel path R in the parking P is traveling along the traveling path R of the narrow road width W than the parking space search range S _1, for example, the vehicle S, parking P May search for an empty parking space.
However, in this case, as shown in FIG. 16B, if the host vehicle S travels along a position near the parking frame A existing on the left side of the traveling path, the parking frame B present on the right side of the traveling path R never a parking space detection range S ₁ of the vehicle S overlap. That is, when the road width W of the travel path R is narrow, if the vehicle travels along the center position β in the width direction of the travel path R, the parking frame A and B existing on the left and right of the travel path R are simultaneously it is possible to overlay the parking space detection range S _1. However, if the vehicle travels along a position close to either of the parking frames A and B existing on the left and right of the traveling path R, it is not possible to search for an empty state of the opposite parking frame. Therefore, in order to detect an empty parking frame, it is necessary to reciprocate the traveling path R, and there arises a problem that it takes time to search for an empty parking frame.

  Thus, unless the travel route within the travel route R of the host vehicle S is set to an appropriate position, there is a problem that it is difficult to search for an empty parking frame and the search for the parking frame cannot be performed appropriately.

[Parking frame search support function]
(Parking assistance)
When parking the host vehicle S of the first embodiment, first, the host vehicle S stops at an arbitrary position such as the entrance of the parking lot P as shown in FIG. In addition, you may drive | work by the driver | operator's manual operation to the said arbitrary positions, and you may drive | work by the automatic driving | operation based on the control signal from parking assistance ECU100 mounted in the own vehicle S.

  When the host vehicle S stops, the driver turns on the search mode switch 19 to perform the parking support process shown in FIG. That is, in the flowchart shown in FIG. 14, the process proceeds from step S101 to step S102, and it is determined whether or not there is an empty parking frame in which the host vehicle S can be parked.

Here, as shown in FIG. 17A, if the detection of free parking frame, the process proceeds to step S102 → step S103, after having set the target parking frame M, the current position of the vehicle S (parking start position) from O ₁ generating a parking path Z to the target parking frame _{O 2} (see FIG. 17B). When the parking route Z is generated, the process proceeds from step S104 to step S105 to step S106, and the current steering position of the host vehicle S and the target steering angle and the target speed for driving the vehicle following the parking route Z are set.

When the target steering angle and the target speed are set, the process proceeds to step S107 where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking route Z. Then, the flow of step S104 → step S105 → step S106 → step S107 → step S108 is repeated until the host vehicle S is parked in the target parking frame M, and the host vehicle S is parked in the target parking frame M.
When the position of the target parking frame M is corrected while the traveling route of the host vehicle S is following the parking route Z, the parking route Z is also corrected as appropriate. Then, the traveling route of the host vehicle S is caused to follow the corrected parking route Z.

(Free parking space search: 1st pattern)
On the other hand, as a result of determining the presence or absence of an empty parking frame, if an empty parking frame cannot be detected, the process proceeds from step S102 to step S109. When the passage travel mode switch 20 is turned ON, the process proceeds to step S200, and an empty parking frame search route setting process is performed.
When the passage travel mode switch 20 is not turned ON, the parking frame search route α is not set, and the driver searches for an empty parking frame while traveling on an arbitrary route.

  When the empty parking frame search route setting process is performed, that is, in the flowchart shown in FIG. 15, the process proceeds from step S201 to step S202, and the travel path R and the road width W of the travel path R are detected, and then the travel path It is determined whether or not the R road width W is wider than a preset predetermined road width threshold Th.

  As shown in FIG. 18A, when the road width W of the travel path R is equal to or smaller than the road width threshold Th, the process proceeds from step S202 to step S213, and the parking frame search path α is set along the center position β in the width direction of the travel path R. Set. When the parking frame search route α is set, the process proceeds from step S110 to step S111 to step S112 shown in FIG. 14, and the current steering position of the host vehicle S, the target steering angle when the vehicle follows the parking frame search route α, and Set each target speed.

  When the target steering angle and the target speed are set, the process proceeds to step S113, where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking frame search route α. Until the own vehicle S detects an empty parking frame, the flow of step S109 → step S200 → step S110 → step S111 → step S112 → step S113 is repeated to search for an empty parking frame.

At this time, as shown in FIG. 18B, the host vehicle S travels along the center position in the width direction of the travel path R by setting the parking frame search path α along the center position in the width direction of the travel path R. . Therefore, the presence or absence of an empty parking frame can be simultaneously searched for the parking frames A and B existing on the left and right sides of the travel path R, respectively.
That is, by vehicle S is traveling in the width direction center position of the travel path R, overlapping the parking space search range S ₁ of the vehicle S, the parking space A present on both right and left sides of the travel path R, each of B be able to. As a result, an empty parking frame can be detected in a short time without going back and forth on the travel path R.

(Free parking space search: 2nd pattern)
Further, as shown in FIG. 19A, when the road width W of the road R is wider than the road width threshold Th, the process proceeds from step S202 to step S203, and whether or not there is a parking frame on the left side of the road R. to decide. In the case shown in FIG. 19A, since the left side of the road R can be determined that the parking space A is present, the process proceeds to step S204, the travel path relative to the left parking frame A, fitting the first straight line A ₁ (FIG. 19B).

After fitting the first straight line A _1, the routine proceeds to step S205, the parking space is determined whether there on the right side of the travel path R. In the state shown in FIG. 19B, the parking space search range S ₁ of the vehicle S do not overlap in the parking space B of the road right, it is not possible to detect the parking space B of the traveling path right. Therefore, it is determined that there is no parking frame on the right side of the traveling path R, and the process proceeds to step S208.
As a result, as shown in FIG. 19C, it sets the parking space search path α along the position away from the first straight line A ₁ of fitting a predetermined distance L ₁ with respect to the running path left parking frame A.

  When the parking frame search route α is set, the process proceeds from step S110 to step S111 to step S112 shown in FIG. 14, and the target steering angle when the vehicle follows the current position of the host vehicle S and the parking frame search route α. And the target speed are set.

  When the target steering angle and the target speed are set, the process proceeds to step S113, where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking frame search route α. Until the own vehicle S detects an empty parking frame, the flow of step S109 → step S200 → step S110 → step S111 → step S112 → step S113 is repeated to search for an empty parking frame.

In this case, as shown in FIG. 19C, it was set from the first straight line A ₁ of fitting a predetermined distance L ₁ away parking space search path along the position α with respect to the parking space A present roadway left The host vehicle S travels at a position closer to the parking frame A than the center position β in the width direction of the travel path R (see FIG. 19C). Therefore, it is possible to appropriately search for the parking frame A on the left side of the travel path, and to easily detect an empty parking frame.

(Free parking space search: 3rd pattern)
When the road width W of the road R is wider than the road width threshold Th, the process proceeds from step S202 to step S203, and when it is determined whether or not a parking frame exists on the left side of the road R, FIG. As described above, when it cannot be determined that the parking frame exists on the left side of the travel path R, the process proceeds to step S209, and it is determined whether or not the parking frame exists on the right side of the travel path R. In the case shown in FIG. 20A, since the right side of the travel path R can be determined that the parking frame B is present, the process proceeds to step S210, the travel path relative to the right side of the parking frame B, fitting a second straight line B ₁ (Fig. 20B).

When the second fitting a straight line B _1, proceeds to step S211, as shown in FIG. 20C, a position away from the second straight line B ₁ of fitting by a predetermined distance L ₂ to the traveling path right parking frame B A parking frame search route α is set along the route.

  When the parking frame search route α is set, the process proceeds from step S110 to step S111 to step S112 shown in FIG. 14, and the target steering angle when the vehicle follows the current position of the host vehicle S and the parking frame search route α. And the target speed are set.

  When the target steering angle and the target speed are set, the process proceeds to step S113, where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking frame search route α. Until the own vehicle S detects an empty parking frame, the flow of step S109 → step S200 → step S110 → step S111 → step S112 → step S113 is repeated to search for an empty parking frame.

At this time, as shown in FIG. 20C, the running path that sets the parking space search path α along the second straight line B ₁ which is fitted to a predetermined distance L ₂ apart position relative to the parking space B present in the right The host vehicle S travels at a position closer to the parking frame B than the center position β in the width direction of the travel path R (see FIG. 20C). Therefore, it is possible to appropriately search for the parking frame B on the right side of the travel path, and to easily detect an empty parking frame.

(Free parking space search: 4th pattern)
Furthermore, when the road width W of the road R is wider than the road width threshold Th, when it is determined whether a parking frame exists on the left side of the road R, as shown in FIG. When it is determined that the parking frame A exists, and when it is determined that the parking frame B exists on the right side of the traveling path R, the process proceeds from step S202 to step S203 to step S204 to step S205 to step S206. That is, for roadway left parking frame A, the first straight line A ₁ fitted, with respect to the running path right parking frame B, and fitting a second straight line B ₁ (see FIG. 21B). As a result, the first and second straight lines A ₁ and B ₁ are fitted to the left and right sides of the travel path R.

In the first embodiment, after fitting the _first and second straight lines A ₁ and B ₁ , the process proceeds to step S207, and the vehicle S at that time of the first straight line A ₁ and the second straight line B ₁ is selected. A parking frame search route α is set along a position that is a predetermined distance L ₁ away from a straight line determined to be closer to the position (first straight line A _{1 in} FIG. 21C).

  When the parking frame search route α is set, the process proceeds from step S110 to step S111 to step S112 shown in FIG. 14, and the target steering angle when the vehicle follows the current position of the host vehicle S and the parking frame search route α. And the target speed are set.

  When the target steering angle and the target speed are set, the process proceeds to step S113, where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking frame search route α. Until the own vehicle S detects an empty parking frame, the flow of step S109 → step S200 → step S110 → step S111 → step S112 → step S113 is repeated to search for an empty parking frame.

In this case, as shown in FIG. 21C, it was set from the first straight line A ₁ of fitting a predetermined distance L ₁ away parking space search path along the position α with respect to the parking space A present roadway left The host vehicle S travels at a position closer to the parking frame A than the center position β in the width direction of the travel path R (see FIG. 21C). Therefore, it is possible to appropriately search for the parking frame A on the left side of the travel path, and to easily detect an empty parking frame.

(Free parking space search: 5th pattern)
Although not shown, when it is determined that there are no parking frames on either side of the travel path R, the process proceeds from step S202 to step S203 to step S209 to step S212 in the flowchart shown in FIG. Then, the parking based preset to "parking searched route alpha, roadway than widthwise middle position β of R is set along a position a predetermined distance L ₃ which is set in advance to the left" of travel rule Sets the frame search path α.

  When the parking frame search route α is set, the process proceeds from step S110 to step S111 to step S112 shown in FIG. 14, and the target steering angle when the vehicle follows the current position of the host vehicle S and the parking frame search route α. And the target speed are set.

  When the target steering angle and the target speed are set, the process proceeds to step S113, where the vehicle travels while controlling the steering angle and speed of the host vehicle S, and the travel route of the host vehicle S follows the parking frame search route α. Until the own vehicle S detects an empty parking frame, the flow of step S109 → step S200 → step S110 → step S111 → step S112 → step S113 is repeated to search for an empty parking frame.

  In this way, by setting the parking frame search route α based on a preset travel rule, the parking frame search accuracy can be improved compared to the case where the vehicle travels unplanned in the travel route R. A search for a parking frame on the side of the road R can be performed appropriately, and an empty parking frame can be easily detected.

Next, the effect will be described.
In the parking assistance method and the parking assistance device of the first embodiment, the effects listed below can be obtained.

(1) In the parking support method for supporting the search for an empty parking frame of the host vehicle S by the parking controller (parking support ECU 100) mounted on the host vehicle S,
A road width detecting step (step S201) for detecting the road width W of the traveling path R in the parking lot P when entering the parking frame;
A parking frame search route setting step (steps S202 to S213) for setting in the travel route R a parking frame search route α for searching for an empty parking frame during travel according to the road width W of the travel route R;
A host vehicle guidance step (steps S110 to S113) for guiding the host vehicle S based on the parking frame search route α;
It was set as the structure which has.
This makes it easier to search for an empty parking frame when traveling in a parking lot while searching for an empty parking frame.

(2) In the parking frame search route setting step (steps S202 to S213), when the road width W of the road R is wider than a predetermined road width threshold Th set in advance, the width direction central position β of the road R The parking frame search route α is set along a position that is biased to the left or right of the road, and when the road width W of the road R is equal to or less than the road width threshold Th, the width direction central position β of the road R is set. The parking frame search route α is set.
As a result, in addition to the effect of (1), it is possible to appropriately search for an empty parking frame even when the road width W of the road R is wide, and to search for an empty parking frame when the road width W of the road R is narrow. It can be done efficiently.

(3) In the parking frame search route setting step (steps S202 to S213), when the parking frame search route α is set along a position that is biased to the left or right of the center position β in the width direction of the travel route R. The parking frame search route α is set along a position separated from the parking frames A and B existing along the travel path R by predetermined distances L ₁ and L ₂ .
Thereby, in addition to the effect of (2), it can be made to drive | work along the position which approached the parking frames A and B which exist along the driving path R, and it can make it easier to search for an empty parking frame. .

(4) In the parking frame search route setting step (steps S202 to S213), when the parking frame search route α is set along a position that is biased to the left or right of the width direction center position β of the travel route R. The parking frame search route α is set based on a predetermined travel rule.
Thereby, in addition to the effect of (2), even when the existence of a parking frame is unclear, it is possible to make it easier to search for an empty parking frame than when traveling unplanned.

(5) A parking support device including a parking controller (parking support ECU) that supports the search for an empty parking frame of the host vehicle S,
The parking controller (parking support ECU)
When entering the parking frame, the road width W of the traveling path R in the parking lot P is detected,
According to the road width W of the travel path R, a parking frame search path α for searching for an empty parking frame during travel is set in the travel path R,
The host vehicle S is guided based on the parking frame search route α.
This makes it easier to search for an empty parking frame when traveling in a parking lot while searching for an empty parking frame.

  As mentioned above, although the parking assistance method and the parking assistance apparatus of this invention have been demonstrated based on Example 1, it is not restricted to this Example about a concrete structure, Each claim of a claim Design changes and additions are allowed without departing from the gist of the invention.

In the first embodiment, when a parking frame cannot be detected on either of the left and right sides of the travel path R, “a predetermined distance L ₃ that is set in advance on the left side of the travel path R in the width direction center position β of the travel path R. An example is shown in which the parking frame search route α is set based on the travel rule “set along a position that is only a distance away”. However, the present invention is not limited to this, and the travel rules can be set arbitrarily.
That is, for example, preset driving rule information is received from the base station X installed in the parking lot P or another vehicle (parked vehicle B) already parked in the parking lot P, and the received driving rule information Based on this, the parking frame search route α may be set.

  Further, the contents of the signs installed in the parking lot P and the position of the lane provided on the travel route R may be recognized, and the parking frame search route α may be set according to the contents of the signs and the position of the lane.

Further, as a travel rule, “the parking frame search route α may be set based on the travel position of a preceding vehicle or a subsequent vehicle traveling on the travel route R”. Here, the “preceding vehicle” is another vehicle traveling immediately before the host vehicle S (see FIG. 22). The “following vehicle” is another vehicle that is traveling immediately after the host vehicle S.
Note that “based on the travel position of the preceding vehicle (or subsequent vehicle)” refers to traveling along a route along which the preceding vehicle (or subsequent vehicle) is traveling. That is, when the preceding vehicle (or subsequent vehicle) is traveling on the left side of the center position β in the width direction of the traveling path R, the traveling path R is on the left side (two lanes for face-to-face traveling) as shown in FIG. It is determined that there is a parking frame search route α on the left side of the center position β in the width direction of the travel route R. Further, when the preceding vehicle (or the following vehicle) is traveling on the right side of the center position β in the width direction of the traveling path R, it is determined that the traveling path R is right-hand traffic (two lanes for face-to-face traveling), and the traveling path A parking frame search route α is set on the right side of the center position β in the width direction of R. Furthermore, when the preceding vehicle (or the following vehicle) is traveling in a region within the set width from the center position β in the width direction of the travel path R, it is determined that the travel path R is one-way, and the road width W of the travel path R is determined. Is equal to or less than the road width threshold Th, the parking frame search route α is set along the center position β in the width direction of the travel route R.

Furthermore, as a travel rule, “the parking frame search route α may be set based on the travel position of the oncoming vehicle traveling on the travel route R”. Here, the “oncoming vehicle” is another vehicle that travels from the front of the host vehicle S toward the host vehicle S (see FIG. 23).
Note that “based on the traveling position of the oncoming vehicle” refers to traveling along a position offset with respect to the route on which the oncoming vehicle is traveling. That is, when the oncoming vehicle is traveling on the right side of the center position β in the width direction of the travel path R, it is determined that the travel path R is left-hand traffic (two lanes for face-to-face travel), and as shown in FIG. The parking frame search route α is set on the left side of the width direction center position β of the travel route R. Further, when the oncoming vehicle is traveling on the left side of the center position β in the width direction of the travel path R, it is determined that the travel path R is right-hand traffic (two lanes for face-to-face travel), and the center in the width direction of the travel path R is determined. A parking frame search route α is set on the right side of the position β.

Furthermore, as shown in FIG. 24, when setting the parking frame search route α, the vehicle is separated from the end of the parked vehicle B parked in the parking frame K existing along the traveling path R by a predetermined distance L _4. The parking frame search route α may be set along the determined position.
In this case, the distance between the already parked parked vehicle B and the host vehicle S can be secured during the search for the empty parking frame of the host vehicle S, for example, when the parked vehicle B suddenly leaves the store. However, it is possible to make it difficult for the vehicle S to travel.

Furthermore, as shown in FIG. 25, when setting the parking frame search route α, an object such as a human is between the parking frame K existing along the travel route R and the center position β in the width direction of the travel route R. when D is present, it may set the parking space search path α along the travel path away from the object D present in the R by a predetermined distance L ₅ position.
In this case, the distance between the object D and the own vehicle S can be secured in the search for an empty parking frame of the own vehicle S. For example, even when the object D suddenly moves, the travel of the own vehicle S can be ensured. Can be made difficult to affect.

In the first embodiment, when the road width W of the travel path R is wider than the road width threshold Th, the first straight line A ₁ fitted to the parking frame A existing along the travel path R is separated by a predetermined distance L _1. An example in which the parking frame search route α is set along the position or the like has been shown. Further, the example in which the predetermined distance L _{1 and the} like are set to a half distance of the parking frame recognition range S ₁ of the host vehicle S is shown. However, the present invention is not limited to this, and the predetermined distance from the straight line fitted to the parking frame to the parking frame search route α can be arbitrarily set.
Further, by using the map shown in FIG. 26, it may be variable in length, such as a predetermined distance L ₁ in accordance with the height of the parking frame A or other vehicles such recognition accuracy. In other words, setting a predetermined distance L ₁ within the region indicated by hatching in FIG. 26, the recognition accuracy of such parking space A to be able to be set higher increase the length of the predetermined distance L _1.

  Thus, the lower the recognition accuracy of the parking frame A or the like, the closer the parking frame search route α can be to the parking frame A or the like, and the search accuracy of the empty parking frame can be improved. Further, as the recognition accuracy of the parking frame A and the like increases, the parking frame search route α can be separated from the parking frame A and the like, and the degree of freedom for setting the parking frame search route α can be increased.

The “recognition accuracy of the parking frame A” is represented by an error of the recognition position with respect to the true value of the position of the parking frame A. The smaller the error, the higher the “recognition accuracy of the parking frame A”.
Examples of the cause of the “recognition position error relative to the true value of the position of the parking frame A” include the following.
An error due to distortion of the lenses of the cameras 25 to 28 mounted on the host vehicle S. In this case, the error increases as the distance from the center of the imaging surface increases.
An error at the time of overhead conversion when an overhead video is generated from image signals detected by the cameras 25 to 28. In this case, the error increases as the distance from the host vehicle S (cameras 25 to 28) increases.
・ Errors due to road inclination and distortion. In this case, the error increases as the slope or distortion of the road surface increases.

In order to obtain the “recognition accuracy of the parking frame A”, first, a difference between the true value of the parking frame K and the recognition value of the host vehicle S is measured in advance using a surveying device or the like (see FIG. 27A). ), An error map shown in FIG. 27B is created. Here, an error based on parameters such as the frame position on the imaging surface, the inclination of the road surface, and distortion may be included in this error map.
Then, based on the distance between the host vehicle S and the parking frame when the parking frame is detected and the error map shown in FIG. 27B, the position errors X and Y and the angle error are obtained. And "recognition accuracy of parking frame A etc." is set from each calculated | required error.

  Further, a function for obtaining each error may be designed, and the position error X, Y and the angle error may be obtained using the designed function. Further, the function for obtaining the error may be obtained from an overhead view image. Alternatively, it may be calculated from the lenses of the cameras 25 to 28 or the overhead view conversion model.

Furthermore, in Example 1, although the parking frame, the driving | running | working path R, etc. were shown by analyzing the bird's-eye view video produced | generated by carrying out bird's-eye conversion of the image signal detected by the cameras 25-28, it showed the example. Not limited to this. For example, a laser scanner or sonar sensor may be mounted on the host vehicle S, and a parking frame or the like may be detected based on a detection signal from the laser scanner or the like. Moreover, you may use combining a laser scanner etc. and the cameras 25-28.
In addition, the shape of the parking frame detection range when using a laser scanner or the like and the parking frame detection range when using the cameras 25 to 28 may be different. However, even if the shape of the parking frame detection range is different, the method for setting the parking frame search route α can be similarly implemented.

  Further, in the first embodiment, when the parking frame search route α is generated, the parking support method for controlling the host vehicle S along the parking frame search route α and performing the empty parking frame search traveling by the automatic operation by the parking support ECU 100 is provided. Although shown, it is not limited to this. For example, a parking assist method may be used in which the generated parking frame search route α is displayed on the vehicle-mounted monitor 18 so that the driver can perform a parking operation while viewing the displayed parking frame search route α. In addition, although the driver performs an operation at the time of searching for an empty parking frame, if the driving route of the vehicle S is significantly deviated from the parking frame searching route α, a parking assist method by semi-automatic driving that corrects the steering angle etc. There may be. Furthermore, guidance of the parking frame search route α may be performed by voice.

100 Parking assistance ECU (controller)
S own vehicle 10 engine 11-14 wheel 16 steering wheel 25-28 camera 101 parking frame recognition unit 102 target parking frame setting unit 103 parking start position setting unit 104 parking route generation unit 105 parking frame search route setting unit 107 route following control unit 108 Target speed generation unit 109 Position estimation unit in parking route 110 Position estimation unit in search route 112 Steering angle control unit 113 Speed control unit

Claims (8)

In the parking support method for supporting the search for an empty parking frame of the host vehicle by a parking controller mounted on the host vehicle,
A road width detecting step for detecting a road width of a running road in the parking lot when entering the parking frame;
A parking frame search route setting step for setting a parking frame search route for searching for an empty parking frame during travel in the travel route according to the width of the travel route;
A host vehicle guidance step for guiding the host vehicle based on the parking frame search route;
The parking assistance method characterized by having. In the parking assistance method according to claim 1,
In the parking frame search route setting step, when the road width of the travel path is wider than a predetermined road width threshold set in advance, the parking frame search is performed along a position that is biased to the left or right of the center position in the width direction of the travel path. A parking support method, comprising: setting a route, and setting the parking frame search route along a center position in a width direction of the traveling road when a road width of the traveling road is equal to or less than the road width threshold value. In the parking assistance method according to claim 2,
In the parking frame search route setting step, when the parking frame search route is set along a position that is biased to the left or right of the center position in the width direction of the travel path, a predetermined distance from the parking frame that exists along the travel path A parking assist method, wherein the parking frame search route is set along a position separated by a distance. In the parking assistance method according to claim 2,
In the parking frame search route setting step, the parking frame search route is set based on a predetermined driving rule when the parking frame search route is set at a position that is biased to the left or right of the center position in the width direction of the travel route. A parking support method, characterized by setting. In the parking assistance method according to claim 2,
In the parking frame search route setting step, when the parking frame search route is set at a position that is biased to the left or right of the center position in the width direction of the travel path, the vehicle is parked in a parking frame that exists along the travel path. The parking assist method, wherein the parking frame search route is set along a position away from the parked vehicle by a predetermined distance. In the parking assistance method according to claim 2,
In the parking frame search route setting step, when the parking frame search route is set to a position that is biased to the left or right of the center position in the width direction of the travel path, the parking frame search path is separated from an object existing in the travel path by a predetermined distance. A parking assist method, wherein the parking frame search route is set along a position. In the parking assistance method according to claim 2,
In the parking frame search route setting step, the parking frame search route is set based on the parking position recognition performance of the host vehicle when the parking frame search route is set to a position that is biased to the left or right of the center position in the width direction of the travel path. A parking support method characterized by setting a frame search route. A parking support device including a parking controller that supports the search for an empty parking frame of the host vehicle,
The parking controller
When entering the parking frame, detect the width of the road in the parking lot,
According to the road width of the travel path, a parking frame search route for searching for an empty parking frame during travel is set in the travel path,
The parking assistance device, wherein the vehicle is guided based on the parking frame search route.