JP2002240661A - Parking support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking support device allowing a vehicle to be placed in the desired parking space upon avoiding eventual obstacle lying ahead in the advancing direction during parking operation. SOLUTION: In the case that a parking operation start SW 13 has sensed an instruction of the start of parking given by the driver, a control unit 29 sets as a target the position having a certain relation with respect to the vehicle position when the instruction is sensed, and calculates the relative positional relationship between the current vehicle position and target position, and if a reversing operation of the vehicle is started by a shift lever select SW 17, the target track for the vehicle is calculated and displayed on a monitor 27 on the basis of the positional relationship between the current vehicle position and target position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parking assist device for assisting a driving operation when a vehicle is parked, and more particularly, to guiding a target trajectory of the vehicle from a current position of the vehicle to a target parking position when the vehicle retreats. The present invention relates to a parking assist device.

[0002]

2. Description of the Related Art Conventionally, a parking assist device has been disclosed in
An "automatic steering device for a vehicle" described in Japanese Patent Application Publication No. 1-78936 has been reported.

[0003] In this parking assist device, when a driver operates a parking switch at a predetermined position in a parking space, the vehicle is automatically steered according to a predetermined trajectory, and the vehicle is parked in the parking space. The automatic steering is stopped when an obstacle is detected ahead in automatic steering or when a driver finds an obstacle and performs a steering operation voluntarily.

[0004]

However, in the conventional parking assist device, the vehicle is automatically steered according to a predetermined trajectory from the time when the parking start switch is operated, and an obstacle is generated during the automatic steering. If there is, there is a problem that parking cannot be performed in a parking space because the parking operation is stopped.

[0005] The present invention has been made in view of the above,
The purpose is to avoid obstacles even if there is an obstacle ahead in the traveling direction during parking operation,
An object of the present invention is to provide a parking assist device that can park in a desired parking space.

[0006]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, in a parking assistance device that assists a driving operation when parking a vehicle, a parking start detection unit that detects a parking start instruction by a driver and a parking start instruction that is detected by a driver A target setting means for setting a position having a predetermined relationship as a target position with respect to a vehicle position at the time of detecting an instruction to start parking, and a relative positional relationship between a current vehicle position and the target position. A positional relation calculating means for calculating, a reverse operation start detecting means for detecting whether or not the backward operation of the vehicle has been started, and a current position of the vehicle calculated by the positional relation calculating means when the backward operation of the vehicle is started. Target trajectory calculating means for calculating a target trajectory of the vehicle based on a positional relationship between the position and the target position, and a target trajectory plan for guiding the target trajectory calculated by the target trajectory calculating means And summarized in that and means.

According to a second aspect of the present invention, there is provided a distance measuring means for measuring a distance from a vehicle to an obstacle, and a predetermined distance measuring data among distance measuring data obtained from the distance measuring means. A distance measurement data storage unit for storing distance measurement data for a moving distance; and a vehicle that moves a space closest to the vehicle from a point in time when a parking start instruction is detected based on a distance data string stored in the distance measurement data storage unit. Parking position determining means for determining the parking position of the vehicle, parking direction determining means for determining the vehicle direction at the time of parking with respect to the vehicle direction at the start of parking, a distance measurement data string stored in the distance measurement data storage means, The gist of the present invention is to include target parking position setting means for setting a target parking position based on the parking place determined by the position determining means and the vehicle direction at the time of parking obtained by the parking direction determining means.

According to a third aspect of the present invention, in order to solve the above-mentioned problems, a parking method identifying means for identifying parallel reverse parking or parallel parking, and a target parking position corresponding to the identification result by the parking method identifying means are set. And a target parking position setting unit that performs the setting.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, the gist of the invention is that the parking method identification means includes a switch for selecting between parallel reverse parking and parallel parking.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, the parking method identifying means includes a distance measuring means for measuring a distance to an obstacle, and a distance measuring data obtained from the distance measuring means. Based on a distance measurement data storage means for storing distance measurement data for a predetermined moving distance, and a pattern of a distance data string stored in the distance measurement data storage means,
The gist of the invention is to provide a surrounding vehicle parking direction determining means for determining in which direction a vehicle parked around the own vehicle is parked with respect to the moving direction of the own vehicle.

According to a sixth aspect of the present invention, there is provided a navigation system for displaying a traveling route of a vehicle and a current position in a superimposed manner on a map and outputting position information of the vehicle or information of facilities around the vehicle. A gist is provided, wherein the parking method identification means identifies parallel reverse parking and parallel parking based on position information or facility information obtained from the navigation device.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, the parking direction determining means includes a trajectory storing means for storing a past vehicle trajectory within a predetermined distance range from the vehicle, and according to the past vehicle trajectory. The main point is to correct the target parking position and the vehicle body direction at the time of parking.

According to an eighth aspect of the present invention, in order to solve the above problem, the target trajectory calculating means calculates a divergence degree from a target trajectory based on a relative position of the vehicle with respect to the target position. And recalculation determining means for determining whether recalculation of the target trajectory is necessary based on the degree of divergence calculated by the degree of divergence calculating means, and the recalculation determining means has determined that recalculation of the target trajectory is necessary. In some cases, the trajectory calculation is performed again.

According to a ninth aspect of the present invention, in order to solve the above problem, the point is that the center uses the midpoint of the rear wheel axle of the host vehicle as a reference point.

[0015]

According to the first aspect of the present invention, when a parking start instruction is detected by a driver, a position having a predetermined relationship with a vehicle position when the parking start instruction is detected. Is set as the target position, and the relative positional relationship between the current vehicle position and the target position is calculated, and when the backward operation of the vehicle is started, the current position of the vehicle and the target position are set. Based on the positional relationship, the target trajectory of the vehicle is calculated and guided, so that the driver who visually recognizes the target trajectory from the current position of the vehicle to the target position must perform a driving operation so that the vehicle retreats on the target trajectory. Can be. In particular,
Even if there is an obstacle ahead in the direction of travel during the parking operation, avoiding the obstacle and starting the reverse operation of the vehicle will recognize the target trajectory from the current position of the vehicle to the target position. Thus, parking can be performed in a desired parking space.

According to the second aspect of the present invention, of the distance measurement data obtained by measuring the distance from the vehicle to the obstacle, the distance measurement data for a predetermined moving distance is stored. In addition, based on the stored distance data string, the closest space from the time when the parking start instruction is detected is determined as a parking place of the vehicle, and further, parking in the vehicle body direction at the time of parking start is performed. The vehicle direction at the time is determined, and the target parking position is set more accurately by setting the target parking position based on the stored distance measurement data string, the determined parking location, and the vehicle direction at the time of parking. Can be set.

According to the third aspect of the present invention, it is determined whether the vehicle is in parallel reverse parking or parallel parking, and a parallel reverse parking or parallel parking in which a target parking position is set in accordance with the identification result. It is possible to set an appropriate target parking position.

According to the fourth aspect of the present invention, the driver selects between parallel reverse parking and parallel parking, so that an accurate target parking position according to the driver's intention can be easily set.

According to the fifth aspect of the present invention, distance measurement data for a predetermined moving distance among distance data to an obstacle is stored, and a pattern of the stored distance data string is stored. Based on the vehicle, the vehicle parked around the own vehicle is determined to be in the direction of the movement of the own vehicle in the direction in which the vehicle is parked. Since the target parking position can be set, and at the same time, the driver does not need to input the parallel reverse parking or the parallel parking, the operation load can be reduced.

According to the present invention, an accurate target parking position is set by identifying parallel reverse parking and parallel parking based on position information or facility information obtained from a navigation device. At the same time, the driver does not need to input the parallel reverse parking or the parallel parking, so that the operation load can be reduced.

According to the present invention, a past vehicle locus within a predetermined distance range from the vehicle is stored,
By correcting the target parking position and the vehicle body direction at the time of parking according to the past vehicle trajectory, the driver can be more accurately guided using the past vehicle trajectory.

According to the present invention, the degree of deviation from the target trajectory is calculated based on the relative position of the vehicle to the target position, and whether the target trajectory needs to be recalculated based on the degree of divergence is determined. When it is determined that recalculation of the target trajectory is necessary, the trajectory calculation is performed again, so that even if the vehicle position deviates from the target trajectory due to the driver's driving operation during retreat, the target trajectory is recalculated. Can be calculated. In particular, even if the driver has performed an avoidance operation due to the appearance of an obstacle, the new target trajectory can be displayed and guided even if the driver deviates from the target trajectory, and the driver can be guided more accurately. become.

According to the ninth aspect of the present invention, the calculation of the target trajectory is facilitated by using the midpoint of the rear wheel axle of the host vehicle as the reference point.

[0024]

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

(First Embodiment) FIG. 1 is a diagram showing a parking assist device 11 according to a first embodiment of the present invention.

First, the configuration of the parking assist device 11 shown in FIG. 1 will be described.

The parking operation start switch 13 is a switch operated by the driver when the driver moves the vehicle to a predetermined position with respect to the parking place.

The shift lever detection SW 15 is a switch for detecting the position of the shift lever operated by the driver, and in particular, detects whether the shift lever is at the backward position.

The parking method selection switch 17 is a switch operated by the driver to select whether to perform reverse parallel parking or parallel parking.

The parking place selection switch 19 is a switch operated by the driver to select whether to park on the left side or the right side with respect to the traveling direction of the vehicle.

The vehicle speed sensor 21 is composed of, for example, a magnetic or optical encoder provided on a rotating shaft of a wheel, and detects a traveling speed of the vehicle.

The steering angle sensor 23 detects the neutral point, the steering angle, and the steering direction of the steering operated by the driver, and converts the steering angle to the angle of the steered wheels by multiplying by a predetermined gear ratio.

The camera 25 is a camera provided behind the vehicle, and captures a scene behind the vehicle when the vehicle retreats and outputs an image.

The monitor 27 is, for example, a monitor used in a navigation device or the like. When the driver operates the parking operation start SW 13, the monitor 27 displays an image from a camera used for rearward photographing, and the control unit 2.
By superimposing and displaying the image of the target track calculated by 9, a reference image when the vehicle is parked while moving backward is presented to the driver.

The control unit 29 includes a CPU, R
OM, RAM, an interface circuit (not shown), and the like, execute control processing of the entire apparatus according to a control program stored in a ROM, and determine a parking direction, a target parking position setting function, and a relative position calculation function described later. And provide a target trajectory calculation function.

Next, a process from the determination of the parking direction to the generation of the target trajectory will be described with reference to FIGS.

(1) The parking direction determining function will be described with reference to FIG.

The parking direction determining function determines the direction of the vehicle at the time of parking by either the parallel parking or the parallel reverse parking on the left or right side of the host vehicle when the driver operates the parking operation start SW 13. Function.

FIG. 2 shows a state in which the driver operates the parking operation start SW 13 when performing parallel reverse parking.
It shows a position S where the driver should stop the vehicle 31 with respect to the parking place.

The driver advances the vehicle 31 in a direction substantially perpendicular to the parking space, and moves the vehicle 31 to a position where the driver 33 itself comes on the central axis Ac ′ of the space at the place where parking is desired. Stop at

At this time, the driver selects the parallel reverse parking with the parking method selection SW5 and selects the left side of the own vehicle traveling direction with the parking place selection SW6, so that the parking direction determination function is performed near the shaded area indicated by S. It is determined that the vehicle is parked facing upward as shown in FIG.

In the case of parallel parking, as shown in FIG. 6, the driver stops the vehicle at the position where the rear end of the vehicle 31 enters the parking space S, and performs the same SW selection to determine the parking direction. The function is shown in the vicinity of the lane indicated by S in FIG.
It is determined that the vehicle is parked in the left direction shown in FIG.

(2) The target parking position setting function will be described with reference to FIG.

The target parking position setting function determines a target position at the end of parking of a predetermined reference point (here, the center of the rear wheel axle) on the vehicle body by referring to a parking direction determining function.
The assumption is given that the driver has driven the vehicle to a predetermined position with respect to the parking place.

When the vehicle stops at the position described in FIG.
The driver operates the parking operation start SW 13 to indicate that the parking operation is to be started. Then, the target parking position setting function allows the driver to perform a parking operation start SW13.
The coordinates of point B, which is a predetermined positional relationship when the coordinates of the center of the rear wheel axle are set to the origin 0 at the time when is operated, are set. Coordinates of point B (x _B, y _B) is, (x _B, y _B) = - given by _{(h 2 -h 3 -h 4,} h 1) (1). Here, h ₁ is the distance between the driver's seat and the rear wheel axle, h ₂ is _２ of the vehicle width, h ₃ is the distance between the side of the vehicle and the parking space (for example, about 1 m), h ₄
Is the distance from the vehicle front wheel to the rear wheel axle.

[0046] In the case of parallel parking, as shown in FIG. 7, the B point coordinates (x _B, y _{B) is, (x B, y B)} = (- 2h 2 -h 3, 0) (2 ).

(3) The relative position calculation function will be described with reference to FIG.

The relative position calculation function calculates the motion of the vehicle from the time when the parking operation start SW 13 is operated, using the vehicle speed from the vehicle speed sensor 21 and the steering angle from the steering angle sensor 23, for example. A change in the coordinates of the reference point on the vehicle after the operation start switch 13 is operated and a change in the body direction are calculated.

The coordinate system may be such that the origin is the center D of the rear wheel axle, the x-axis is forward of the vehicle body axis, and the y-axis is the front right side. A ground coordinate system having the origin of the position of the upper reference point D may be used.

The driver sets the coordinates of the center of the rear wheel axle shown in FIG. 4 to D (x _D ,
y _D ), the vehicle 3 moves to the position of θ _d with respect to the x-axis.
Move one. Here, the previously determined origin 0 is the origin in the ground coordinate system. The coordinates (x, y) of the point D and the direction θ of the vehicle body are expressed by the equation of motion (3).

(Equation 1) Can be calculated by solving from time to time. Here, L _wb is the wheel base of the vehicle, θ is the steering angle sensor 2
3 is the front wheel turning angle obtained from FIG.

(4) The target trajectory calculation function will be described with reference to FIG.

The target trajectory calculation function minimizes (maximizes) a predetermined evaluation function using the relative positional relationship and direction relationship that change every moment from the time when the parking operation start SW 13 is operated by the driver. The trajectory is calculated as follows.

More specifically, the target trajectory calculating function is such that the state quantities x, y, and θ appearing in the above-mentioned equation of motion (3) are determined by the equation of motion (3) and the constraint conditions (eg, the maximum steering angle, the range of the vehicle speed, etc.). While the initial state (state at the current position)
(X _d , y _d , θ _d ) to end state (state at the end of parking)
_{(X b, y b, 0} ) to, to calculate the trajectory based on certain determined conditions.

As shown in FIG. 5, in the case of reverse parallel parking, a trajectory of a straight line (Line 1) + an arc having a minimum turning radius (Arc1) + a straight line (Line 2) is conceivable.

Further, as shown in FIG. 9, in the case of parallel parking, a trajectory of straight line (Line1) + arc of minimum turning radius (Arc1) + straight line (Line2) can be considered. These trajectories can be easily calculated from geometric relationships.

Next, the processing flow of the above functions will be described in detail with reference to the general flowchart shown in FIG. 10 and the subroutines shown in FIGS.

First, in FIG. 10, step S100
Then, it is checked whether or not the parking operation start SW 13 is operated by the driver to be turned on. Parking operation start switch
If the key 13 has been operated, the process proceeds to step S110. If the key 13 has not been operated, the process ends.

In step S110, the parking operation start SW
13 is operated and turned on, it is checked whether the parking operation start flag is set. If it is set, the process proceeds to step S200. If it is not set, the process proceeds to step S120.

In step S120, since the parking operation start flag has not been set, the parking operation start flag is set.

In step S200, the vehicle speed sensor 21,
The sensor signal from the steering angle sensor 23 is read. Here, the detailed flow of the sensor signal reading process in step S200 will be described with reference to the flowchart shown in FIG.

In step S210, the vehicle speed is read from the vehicle speed sensor 21. In general, the vehicle speed is obtained by measuring a time interval of a pulse signal generated by, for example, an encoder with rotation of a wheel, and multiplying a reciprocal thereof by an appropriate gain.

In step S220, the steering angle sensor 23
And calculates the steering angle, which is the amount of steering operation. This is obtained by counting pulse signals generated by an encoder provided in the steering unit.

In step S230, step S220
The front wheel steering angle is calculated by multiplying the steering angle obtained in the above by the gear ratio G1 of the steering section. Then, the process returns to the general flow, and proceeds to step S290.

In step S290, it is checked whether the target parking position setting flag has been set. If it is set, the process proceeds to step S500. If it is not set, the process proceeds to step S300.

In step S300, since the target parking position setting flag is not set, the target parking position is calculated and set with the rear wheel axle middle point at the time when the parking operation start flag is set as the origin. Here, the detailed flow of the target parking position setting process in step S300 will be described with reference to the flowchart shown in FIG.

In step S310, a parking method selection switch
17 checks which side of parallel reverse parking or parallel parking is selected. If the parallel reverse parking side has been selected, the process proceeds to step S315, and if the parallel parking side has been selected, the process proceeds to step S320.

In step S315, since the parallel reverse parking is selected, the flag flg_p1 is set.

In step S320, since the parallel parking is selected, the flag flg_p1 is reset.

In step S325, the parking place selection SW
Checks whether the left or right side is selected. If the left side has been selected, the process proceeds to step S330, and if the right side has been selected, the process proceeds to step S335.

In step S330, since the left side has been selected, the flag flg_p2 is set. On the other hand, step S3
At 35, since the right side is selected, the flag flg_p2 is reset.

In steps S340, S345 and S360, the state of the flags flg_p1 and flg_p2 is checked, and steps S350, S355, S365 and S365 are performed according to the flag states.
Proceed to S370. That is, if the right parallel reverse parking is selected, the process proceeds to step S350. If the left parallel reverse parking is selected, the process proceeds to step S355. If the left parallel parking is selected, the process proceeds to step S365. If is selected, the process proceeds to step S370.

[0072] Therefore, in step S350, since the right parallel backward parking is selected, the coordinates (x _b, y _b) of the wheel axle midpoint after the target and, the vehicle body orientation to a target theta _b
Is given by x _b = h ₂ + h ₃ + h ₄ y _b = h ₁ θ _b = π (4)

In step S355, since the left parallel reverse parking is selected, the target coordinates (x _b , y _b ) of the midpoint of the rear axle and the target body orientation θ _b are Given by

In step S365, since the left parallel parking is selected, the coordinates (x _b , y _b ) of the target midpoint of the rear wheel axle and the target body direction θ _b are given by x _b = −2h ₂ −h ₃ y _b = 0 θ _b = π / 2 (6)

In step S370, since parallel parking on the right side is selected, the coordinates (x _b , y _b ) of the target midpoint of the rear axle and the target body orientation θ _b are given by x _b = 2h ₂ + h ₃ y _b = 0 θ _b = π / 2 (7) Then, the process returns to the general flow, and proceeds to step S400.

Returning to FIG. 10, in step S400, a target parking position setting flag is set.

In step S500, the midpoint of the rear axle at the time when the parking operation start flag is set is set as the origin.
According to the motion of the vehicle, the position coordinates (x, y) of the vehicle and the direction θ of the vehicle are calculated. Here, the detailed flow of the relative position calculation processing in step S500 will be described with reference to the flowchart shown in FIG.

In step S505, it is determined whether the initialization for calculating the relative position coordinates and the vehicle body direction has been performed in advance by checking the vehicle position initialization flag. If the initialization flag has been set, the initialization has already been performed, so the process proceeds to step S540. If the initialization flag has been reset, the process proceeds to step S510.

In step S510, since the initialization has not been performed in advance, the vehicle position initialization flag is set.

In step S515, the vehicle body orientation is set to θ ₁ =
Initialize by setting to π / 2.

In step S520, x of the midpoint of the rear wheel axle
Initialize the coordinates by setting x ₁ = 0.

In step S530, y at the midpoint of the rear wheel axle
Initialize by setting the coordinates to y ₁ = 0.

[0083] In step S540, the T _s is the sampling time, the previous sample body facing theta _1, the vehicle speed V measured by the cycle, and a front wheel steering angle phi, obtaining the vehicle body orientation theta _2. Equation (8) is obtained by discretizing the differential equations using the sampling time T _s the differential equation of Formula (3).

[0084]

(Equation 2) In step S550, using T _s as a sampling time, the x coordinate x ₁ of the rear wheel axle midpoint one sample before, the vehicle body direction θ _1, and the vehicle speed V measured in that cycle are used to determine the x of the rear wheel axle midpoint. determine the coordinate x _2. Equation (9) is obtained by discretizing the differential equations using the sampling time T _s the differential equation of Formula (3).

X ₂ = T _s · V cos φ + x ₁ (9) In step S560, T _{s is set} to the sampling time, and
1 and sample y-coordinate y ₁ of the previous rear wheel axle midpoint, a body-facing theta _1, from the vehicle speed V measured at that period, determine the y-coordinate y ₂ of the rear axle midpoint. Equation (10) is obtained by discretizing the differential equations using the sampling time T _s the differential equation of Formula (3).

[0086] In step S570, θ ₁ = θ ₂ and step S5
The direction of the new vehicle body obtained at 40 is the direction of the vehicle body in this sample.

In step S580, x ₁ = x ₂ is set.
The x-coordinate of the new midpoint of the rear wheel axle obtained in step S550 is set as the body direction in this sample.

In step S590, y ₁ = y ₂ is set, and
The y-coordinate of the new midpoint of the rear wheel axle obtained in step S560 is taken as the body direction in this sample. Then, the process returns to the general flow, and proceeds to step S600.

In step S600, it is determined by the shift lever detection switch 15 whether the driver has selected the shift lever to the backward position. If the shift lever is set to the retreat position, the process proceeds to step S700, and if the shift lever is not set to the retreat position, the process is exited.

In step S700, since the shift lever is selected to retreat, the target trajectory from the vehicle position at the time when the shift lever is moved to the reverse position to the target parking position set in step S300 is calculated. Here, FIG.
Referring to the flowchart shown in FIG. 7, step S700
The detailed flow of the target trajectory calculation process in the above will be described.

Here, as shown in FIGS. 5 and 9, the target trajectory is given by a combination of a straight line and a minimum turning radius for both parallel reverse parking and parallel parking.

Therefore, in step S710, the flag fl
Check if g_p1 is set. If it is set, that is, if parallel reverse parking is selected, the process proceeds to step S715. If it is reset, that is, if parallel parking is selected, step S745.
Proceed to.

In step S715, the equation of the straight line Line1, which is a part of the target trajectory in FIG. 5, is calculated. This straight line coincides with the vehicle body axis when the shift lever is shifted to the reverse position.

In the step S720, the equation of the straight line Line2 which is a part of the target trajectory in FIG. 5 is calculated. This straight line coincides with the vehicle body axis when parking is completed.

In step S725, the equation of the arc Arc1 which is a part of the target trajectory in FIG. 5 is calculated. This arc has a radius equal to the minimum radius of the midpoint of the rear wheel axle determined by the maximum front wheel steering angle, and is in contact with both straight lines Line1 and Line2.

In step S730, a straight line Line1 and an arc
The coordinates of the contact point of Arc1 are calculated.

In step S735, a straight line Line2 and an arc
The coordinates of the contact point of Arc1 are calculated.

In step S740, display data is created from the obtained straight line and arc. Here, the arc is approximated by a predetermined number N of straight lines, and given by a coordinate group representing N + 2 line segments. Then, the process returns to the general flow, and proceeds to step S600.

On the other hand, in step S745, the equation of the straight line Line1, which is a part of the target trajectory in FIG. 9, is calculated. This straight line coincides with the vehicle body axis c when the shift lever is shifted to the reverse position.

In step S750, the equation of the arc Arc1, which is a part of the target trajectory in FIG. 9, is calculated. At the target parking position where parking has been completed, this arc is formed of a portion that is in contact with an axis c ′ indicating the vehicle body direction at the target parking position and extends from the target parking position to a position where c and c ′ intersect the middle line.

In step S755, the equation of the arc Arc2 which is a part of the target trajectory in FIG. 9 is calculated. This arc touches the axis c and touches the arc Arc1. In step S760, the coordinates of the contact point between the straight line Line1 and the arc Arc1 are calculated. In step S765, the coordinates of the contact point between the arc Arc1 and the arc Arc2 are calculated. Step S770
Then, display data to be displayed on the monitor 27 is created from the obtained straight line and arc. Here, the arc is approximated by a predetermined N number of straight lines, and given by a coordinate group representing 2N + 1 line segments. Then, the process returns to the general flow illustrated in FIG. 10 and proceeds to step S800.

In step S800, a target trajectory calculation flag is set. In step S900, in order to display the target trajectory coordinates on the monitor 27, the target trajectory coordinates are converted into a predetermined format of a display system to generate a target trajectory image.

In step S950, the current camera image output from the camera 25 provided at the rear of the vehicle is superimposed on the target trajectory image generated in step 900, displayed on the monitor 27, and presented to the driver.

In step S1000, flags relating to this processing, such as a parking operation start flag, a target parking position setting flag, and a target trajectory calculation flag, are reset, and the process exits from this processing.

As described above, when an instruction to start parking is detected by the driver, a position having a predetermined relationship with the vehicle position at the time when the instruction to start parking is detected is set as a target position. The relative positional relationship between the current vehicle position and the target position is calculated, and when the reverse operation of the vehicle is started, the target position of the vehicle is determined based on the positional relationship between the current position of the vehicle and the target position. Since the trajectory is calculated and displayed, the driver who has visually recognized the target trajectory from the current position of the vehicle to the target position can perform a driving operation so that the vehicle retreats on the target trajectory. In particular, even if an obstacle is present ahead of the traveling direction during the parking operation, avoiding the obstacle and starting the retreat operation of the vehicle will make the target trajectory from the current position of the vehicle to the target position. It is possible to visually recognize and park in a desired parking space.

It is also possible to distinguish between parallel reverse parking and parallel parking, and to set a target parking position according to the result of this identification. It is possible to set an appropriate target parking position according to parallel reverse parking or parallel parking. become.

Further, since the driver selects between parallel reverse parking and parallel parking, a precise target parking position according to the driver's intention can be easily set.

By using the midpoint of the rear wheel axle of the host vehicle as the position of the reference point, the calculation of the target trajectory becomes easy.

(Second Embodiment) FIG. 15 is a view showing a parking assistance device 51 according to a second embodiment of the present invention.

First, the configuration of the parking assist device 51 shown in FIG. 15 will be described. Note that among the components in the present embodiment, those that are the same as the components shown in FIG.
The detailed description is omitted.

A feature of the present embodiment is that it has distance measuring sensors 53a to 53d attached to corner portions of the vehicle.
For example, using ultrasonic waves, laser light, radio waves, etc., by measuring the time from their irradiation to the reception of the reflected wave, to calculate the distance to the obstacle, for example, the left and right of the front end of the vehicle, and the vehicle It is installed at a total of four places on the left and right of the rear end.

Next, the process from the determination of the parking direction to the generation of the target trajectory will be described with reference to FIGS. 16 to 17 taking parallel reverse parking and parallel parking as examples.

(1) The distance measurement data storage function will be described with reference to FIG.

The distance measurement data storage function stores the past distance measurement data measured by each of the distance measurement sensors 53a to 53d.
This is recorded in association with the movement amount of the vehicle. In addition,
The distance measuring sensors 53a to 53d are obtained from the distance of the vehicle on a two-dimensional plane, a reference point for obtaining the vehicle's trajectory and the mounting positions of the distance measuring sensors 53a to 53d, and the distance measuring sensors 53a to 53d. The position of the obstacle may be mapped based on the obtained distance information. In this case, more storage capacity and faster calculation speed are required.

(2) The parking place determining function will be described.

The parking place determining function is based on the distance data from the left distance measuring sensors 53c and 53d and the right distance measuring sensors 53a and 53b on the vehicle body. It is determined that the vehicle is parked.

(3) The parking method determining function is shown in FIGS.
As shown in FIG. 7, it is estimated that the surrounding parked vehicle is parked in the traveling direction of the own vehicle based on the distance pattern measured by the distance measurement sensors 53a to 53d, and the vehicle is parked in parallel backward. Or whether to park in parallel.

Next, the procedure for setting the target parking position is shown in FIG.
This will be described in detail using a general flowchart shown in FIG. 3 and a subroutine shown in FIG. The subroutine shown in FIG. 18 is a subroutine shown in FIG. 12 and shows detailed processing contents specific to the present embodiment with respect to the step S300 which is a part of the general flowchart shown in FIG. It is. The description of the general flowchart illustrated in FIG. 10 is the same as that of the first embodiment, and thus the description is omitted.

Note that the RAM provided in the controller unit 29 records the past distance data measured by the distance measuring sensors 53a to 53d. It is assumed that distance data to an obstacle has been obtained.

In FIG. 18, in step S380,
An average value L _left of the distance data detected on the left side of the vehicle body is calculated.

In step S381, an average value _Lright of the distance data detected on the right side of the vehicle body is calculated.

At step S382, step S380
Average value L _{le ft} of the distance data obtained in step S3
Compare the magnitude of the average value L _right of the distance data obtained in 81, and if L _left is smaller, go to step S388.
If L _left is not smaller, the process proceeds to step S384.

In step S383, since the average value L _left of the distance data is evaluated to be smaller, it is determined that the vehicle is parked on the left side in the vehicle traveling direction, and the flag flg_p2 is set.

In step S384, since it is evaluated that the average value L _left of the distance data is not smaller, it is determined that the vehicle is parked on the right side in the vehicle traveling direction, and the flag flg_p2 is reset.

In the step S385, the point F shown in FIG.
(X _f , y _f ) is detected. As shown in FIG. 16, the point F is an end point on the side closer to the vehicle 55 of the obstacle closest to the host vehicle 55 that is determined to be one continuously detected lump.
In addition, when distance measurement data having close values is obtained in consecutive samples, it is determined that one block is obtained.

In the step S386, the point E shown in FIG.
(X _e , y _e ) is detected. As shown in FIG. 16, the point E is an end point that is continuously detected and is located on the side farthest from the vehicle 55 of the obstacle closest to the host vehicle 55 that is determined to be one lump.

In the step S387, the point G shown in FIG.
(X _g , y _g ) is detected. As shown in FIG. 16, the point G is an obstacle of the own vehicle 5 which is determined to be another lump with a continuous non-detection section opposite to the point E with respect to the point F.
This is the end point closer to 5.

In step S388, the y coordinate of the point F and
The difference between the y coordinates of the point E is determined, and it is checked whether or not the width of the obstacle determined as one lump is smaller than a predetermined reference length Lk. The width of the body of a normal car is 1.
It is about 5m to 2.0m, and the total length of the body is 3.5m to
Since the length Lk is about 5.0 m, the length Lk is set to about 2.5 m which can identify them. Therefore, when the width of the obstacle is 2.5 m or less, the process proceeds to step S389,
If it is larger than 2.5 m, the process proceeds to step S390.

In step S389, the width of the obstacle is 2.
Since the distance is 5 m or less, the surrounding parked vehicle determines that the vehicle is parked at right angles to the traveling direction of the host vehicle, determines that parallel reverse parking is to be performed, and sets the flag flg_p1.

In step S390, the width of the obstacle is 2.
Since the distance is 5 m or more, the surrounding parked vehicle determines that the vehicle is parked in parallel with the traveling direction of the host vehicle, determines that parallel parking is to be performed, and resets the flag flg_p1. An obstacle detected as one lump is, for example, a pillar of a building,
It is conceivable that it is about 0.5 m, and there is a possibility that it is erroneous to judge with the above logic. For example, if the direction of the parked vehicle is determined by taking the intermediate value of a plurality of obstacles,
It goes without saying that more accurate judgment can be made.

In steps S391, S392, and S395, the state of the flags flg_p1 and flg_p2 is checked, and steps S393, S394, and S3 are performed according to the flag states.
96, and proceed to S397. That is, if the right parallel reverse parking has been selected, the process proceeds to step S393. If the left parallel reverse parking has been selected, the process proceeds to step S394.
If the left side parallel parking has been selected, the process proceeds to step S396. If the right side parallel parking has been selected, step S397.
Proceed to.

In step S393, since the right side parallel reverse parking is selected, the coordinates (x _b , y _b ) of the target rear wheel axle midpoint and the target body direction θ _b are x _b = H ₂ + L _right + h ₄ y _b = (y _f + y _e ) / 2 θ _b = π (11)

In step S394, since the left parallel reverse parking is selected, the coordinates (x _b , y _b ) of the target rear wheel axle midpoint and the target body direction θ _b are x _b = given by _{-h 2 -L left -h 4 y b} = (y f + y e) / 2 θ b = 0 (12).

In step S396, since parallel parking on the left side has been selected, the coordinates (x _b , y _b ) of the target midpoint of the rear axle and the target body direction θ _b are given by x _b = −2h ₂ −L _left y _b = y _f + L _m θ _b = π / 2 (13) Here, L _m is the distance from the rear end of the host vehicle to the obstacle at the time when the host vehicle has completed parallel parking,
How opened depends on whether, given by L _m = (distance to the rear wheel axle from the vehicle rear end) + (distance from the vehicle rear to the obstacle).

In step S397, since parallel parking on the right side has been selected, the coordinates (x _b , y _b ) of the target midpoint of the rear axle and the target body direction θ _b are given by x _b = 2h ₂ + L _right y _b = y _f + L _m θ _b = π / 2 (14)

As described above, when an instruction to start parking is detected by the driver, a position having a predetermined relationship with the vehicle position at the time when the instruction to start parking is detected is set as a target position. The relative positional relationship between the current vehicle position and the target position is calculated, and when the reverse operation of the vehicle is started, the target position of the vehicle is determined based on the positional relationship between the current position of the vehicle and the target position. Since the trajectory is calculated and displayed, the driver who has visually recognized the target trajectory from the current position of the vehicle to the target position can perform a driving operation so that the vehicle retreats on the target trajectory. In particular, even if an obstacle is present ahead of the traveling direction during the parking operation, avoiding the obstacle and starting the retreat operation of the vehicle will make the target trajectory from the current position of the vehicle to the target position. It is possible to visually recognize and park in a desired parking space.

Further, of the distance measurement data obtained by measuring the distance from the vehicle to the obstacle, the distance measurement data for a predetermined moving distance is stored, and the stored distance data is stored. Based on the row, the space closest to the point of detection of the parking start instruction is determined as the parking location of the vehicle, and further, the vehicle body direction at the time of parking with respect to the vehicle direction at the time of parking start is determined and stored. By setting the target parking position based on the distance measurement data sequence thus determined, the determined parking location, and the vehicle body direction at the time of parking, a more accurate target parking position can be set.

Further, it is possible to identify whether the vehicle is in parallel reverse parking or parallel parking, and to set a target parking position in accordance with the result of the identification. It is possible to set an appropriate target parking position in accordance with parallel reverse parking or parallel parking. become.

Further, distance measurement data for a predetermined moving distance among the distance data to the obstacle is stored, and the vehicle is parked around the own vehicle based on the stored distance data string pattern. The system determines the direction in which the vehicle is parked with respect to the moving direction of the vehicle, and identifies parallel reverse parking or parallel parking, so that an accurate target parking position can be set. Since the driver does not need to input parallel reverse parking or parallel parking, the operation load can be reduced.

By using the midpoint of the rear wheel axle of the host vehicle as the position of the reference point, the calculation of the target trajectory becomes easy.

(Third Embodiment) FIG. 19 is a view showing a parking assist device 71 according to a third embodiment of the present invention.

First, the configuration of the parking assist device 71 shown in FIG. 19 will be described. Note that among the components in the present embodiment, those that are the same as the components shown in FIG.
Detailed description thereof will be omitted.

A feature of the present embodiment is that a navigation device 73 is provided. The navigation device 73 includes a large-capacity ROM storing map data,
A locator for correcting the position of the own vehicle more accurately by using a satellite positioning by a GPS sensor (not shown) and an autonomous navigation positioning by a gyro sensor and a vehicle speed sensor and an azimuth sensor, and a map around the own vehicle And a monitor for displaying the position of the host vehicle on the map.

The navigation device 73 includes a beacon receiver 75 that receives information transmitted from a beacon installed on the road or in a facility via a beacon antenna 77.
Is connected.

In the present embodiment, for example, when the own vehicle on the road is parked, it is determined that the vehicle is parked in parallel on the left side of the road, and when the own vehicle in the facility is parked, it is determined that the vehicle is backed in parallel. The target parking position is determined based on the determination information. If there is a beacon facility that transmits detailed map information of the facility in the facility, the determination is made based on the beacon information from the beacon facility.

As described above, by identifying parallel reverse parking and parallel parking based on the position information or facility information obtained from the navigation device, an accurate target parking position can be set. Since it is not necessary to input reverse parking or parallel parking, the operation load can be reduced.

Next, the procedure for setting the target parking position is shown in FIG.
0 will be described.

FIG. 20 shows the state at the moment when the parking operation start switch 13 is operated.
Ideally moves along a straight line c, but actually it is meandering and the trajectory is like L.

At the moment when the parking operation start SW 13 is pressed, the vehicle body 79 is in a state of being inclined β with respect to the straight line c. In this state, the target parking position is T1 based on the point P.
However, actually, the T determined with respect to the reference point on the straight line c
3 should be the target parking position, and the error increases.

Therefore, in the present embodiment, the RAM
A regression line c "is obtained from the curve L representing the vehicle trajectory immediately before, which is stored in the reference point Q on the regression line c".
Is determined and the final target parking position is determined, thereby reducing the error from the original position.

As described above, the past vehicle trajectory within a predetermined distance range from the vehicle is stored, and the past vehicle trajectory is corrected by correcting the target parking position and the vehicle body direction at the time of parking according to the past vehicle trajectory. It is possible to more accurately guide the driver by utilizing the information.

Next, the procedure for calculating the target trajectory will be described with reference to FIG.

Here, the initial target trajectory is from D1 to B
It is assumed that the trajectory L _old was However, it is assumed that the vehicle 79 has deviated from the target trajectory due to the operation of the driver, and the reference point has moved from D1 to D2.

Therefore, the position of the reference point when moved by the same distance along the trajectory L _old is defined as D3. Then, when the evaluation criterion is exceeded at this time, a new target trajectory L _new from D2 to B is calculated at the time of reaching D2, so that the target trajectory from the shifted position is displayed on the monitor 27. Can be presented to the driver.

When evaluating the degree of deviation from the target trajectory, the distance between D2 and D3 may be used.

As described above, the degree of deviation from the target trajectory is calculated based on the relative position of the vehicle to the target position, and it is determined whether or not recalculation of the target trajectory is necessary based on the degree of divergence. By re-calculating the trajectory when it is determined that re-calculation is necessary, the target trajectory can be re-calculated even when the vehicle position deviates from the target trajectory due to the driver's driving operation during retreat. In particular, because the driver performed an avoidance operation due to the appearance of obstacles,
Even if the vehicle deviates from the target trajectory, a new target trajectory can be displayed and guided, and the driver can be guided more accurately.

Further, by using the midpoint of the rear wheel axle of the host vehicle as the position of the reference point, the calculation of the target trajectory becomes easy.

In the above-described embodiment of the present invention, the target trajectory is displayed on the monitor. However, even if the target trajectory is guided by voice or the steering is automatically performed so as to become the target trajectory. The same effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a parking assistance device 11 according to a first embodiment of the present invention.

FIG. 2 shows a parking operation start switch when performing parallel reverse parking.
It is a figure which shows the position which should be operated.

FIG. 3 is a diagram illustrating a method of setting a target parking position when performing parallel reverse parking.

FIG. 4 is a diagram illustrating a method of calculating a relative position when performing parallel reverse parking.

FIG. 5 is a diagram illustrating a method of calculating a target trajectory when performing parallel reverse parking.

FIG. 6 is a diagram illustrating a position where a parking operation start SW should be operated when performing parallel parking.

FIG. 7 is a diagram illustrating a method of setting a target parking position when performing parallel parking.

FIG. 8 is a diagram illustrating a method of calculating a relative position when performing parallel parking.

FIG. 9 is a diagram illustrating a method of calculating a target trajectory when performing parallel parking.

FIG. 10 is a general flowchart for explaining an operation of the parking assistance device according to the first embodiment of the present invention.

FIG. 11 is a subroutine flowchart for explaining a sensor signal reading process of the parking assistance device according to the first embodiment of the present invention.

FIG. 12 is a subroutine flowchart for explaining a target parking position setting process of the parking assistance device according to the first embodiment of the present invention.

FIG. 13 is a flowchart of a subroutine for explaining a relative position calculation process of the parking assistance device according to the first embodiment of the present invention.

FIG. 14 is a flowchart of a subroutine for explaining a target trajectory calculation process of the parking assistance device according to the first embodiment of the present invention.

FIG. 15 is a diagram showing a parking assistance device 51 according to a second embodiment of the present invention.

FIG. 16 shows a distance measuring sensor 53 when performing parallel reverse parking.
It is a figure which shows the measurement area of a-53d, and the endpoint of a vehicle.

FIG. 17 shows a distance measurement sensor 53a to parallel parking.
It is a figure which shows the measurement area of 53d and the end point of a vehicle.

FIG. 18 is a subroutine flowchart for describing a target parking position setting process of the parking assistance device according to the second embodiment of the present invention.

FIG. 19 is a diagram illustrating a parking assistance device 71 according to a third embodiment of the present invention.

FIG. 20 is a diagram showing a procedure for setting a target parking position.

FIG. 21 is a diagram showing a procedure for calculating a target trajectory.

[Explanation of symbols]

 11, 51, 71 Parking assistance device 13 Parking operation start SW 15 Shift lever detection SW 17 Parking method selection SW 19 Parking place selection SW 21 Vehicle speed sensor 23 Steering angle sensor 25 Camera 27 Monitor 29 Control unit 53a to 53d Distance measurement sensor 73 Navigation Device 75 Beacon receiver

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B60R 21/00 621 B60R 21/00 621E 621M 622 622B 622C 624 624B 624D 624E 626 626G B62D 6/00 B62D 6 / 00 // B62D 101: 00 101: 00 113: 00 113: 00

Claims (9)

[Claims] 1. A parking assist device for assisting a driving operation when parking a vehicle, comprising: a parking start detecting means for detecting a driver's instruction to start parking; Target setting means for setting a position having a predetermined relationship as a target position with respect to the vehicle position when the parking start instruction is detected, and calculating a relative positional relationship between a current vehicle position and the target position A positional relation calculating means, a reverse operation start detecting means for detecting whether a backward operation of the vehicle has been started, and a current position of the vehicle calculated by the positional relation calculating means when the backward operation of the vehicle is started. Target trajectory calculating means for calculating a target trajectory of the vehicle based on the positional relationship with the target position; and target trajectory guiding means for guiding the target trajectory calculated by the target trajectory calculating means. A parking assist device comprising: 2. Distance measuring means for measuring a distance from a vehicle to an obstacle; and distance measuring data for storing a predetermined distance of moving distance among distance measuring data obtained from the distance measuring means. Storage means; parking location determining means for determining, based on the distance data sequence stored in the distance measurement data storage means, a space closest to the point of detection of the parking start instruction as a vehicle parking location; Parking direction determining means for determining the vehicle body direction at the time of parking with respect to the vehicle body direction at the start, a distance measurement data string stored in the distance measurement data storage means,
Claims: It is provided with target parking position setting means for setting a target parking position based on the parking place determined by the parking place determining means and the vehicle direction at the time of parking obtained by the parking direction determining means. Item 7. The parking assist device according to Item 1. 3. A parking method identifying means for distinguishing between parallel reverse parking and parallel parking, and a target parking position setting means for setting a target parking position according to the identification result by the parking method identifying means. The parking assist device according to claim 1 or 2, wherein 4. The parking assist system according to claim 3, wherein said parking method identification means includes a switch for selecting between parallel reverse parking and parallel parking. 5. The parking method identifying means includes: a distance measuring means for measuring a distance to an obstacle; and distance measuring data for a predetermined moving distance among distance measuring data obtained from the distance measuring means. The distance measurement data storage means for storing, and the direction of the vehicle parked around the own vehicle with respect to the moving direction of the own vehicle, based on the pattern of the distance data string stored in the distance measurement data storage means. The parking assist device according to claim 3, further comprising: a surrounding vehicle parking direction determining unit that determines whether the vehicle is parked in the vehicle. 6. A navigation device that superimposes and displays a traveling route of a vehicle and a current position on a map, and outputs position information of the vehicle or information of facilities around the vehicle. 4. The parking assist device according to claim 3, wherein parallel reverse parking and parallel parking are identified based on position information or facility information obtained from the device. 7. The parking direction determining means includes a trajectory storing means for storing a past vehicle trajectory within a predetermined distance range from the vehicle, and corrects a target parking position and a vehicle body direction during parking according to the past vehicle trajectory. 3. The parking assist device according to claim 2, wherein: 8. A divergence degree calculating means for calculating a divergence degree from a target trajectory based on a relative position of the vehicle with respect to the target position, and a divergence degree calculated by the divergence degree calculating means. And recalculation determining means for determining whether recalculation of the target trajectory is necessary.When the recalculation determining means determines that recalculation of the target trajectory is necessary, the trajectory calculation is performed again. The parking assist device according to claim 1. 9. The parking assist device according to claim 1, wherein the position uses a midpoint of a rear wheel axle of the host vehicle as a reference point.