JP2785472B2 - Automatic parking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic parking apparatus, and more particularly to an apparatus for detecting a sign provided at a predetermined position in a garage and automatically parking the garage.

[Prior Art] Conventionally, an automatic parking device for parking a car by automatic driving has been known. A garage entering method used in this automatic parking device includes a fixed route guidance method in which a traveling route is set in advance and a vehicle is guided along the set traveling route, the coordinates and orientation of the vehicle at the start of entering the garage, and the garage. A required steering angle is obtained from the coordinates and the azimuth of the vehicle at the time of completion of the entry, and two types of point-to-point guidance systems are used, which guide the vehicle based on the required steering angle.

However, if these two methods are used alone, the problem that the driver must drive the vehicle at the initial position and orientation at the start of garage entry and obstacles on the way are not taken into account. However, there has been a problem that the vehicle comes into contact with, for example, a wall of a garage.

Therefore, conventionally, for example, as in the case of a car garage device disclosed in Japanese Utility Model Laid-Open No.
It has been proposed that guidance is provided by a point-to-point guidance method from a combination of the methods to a garage entry start position, and guidance is provided from a garage entry start position to a garage entry end position by a fixed route guidance method.

[Problems to be Solved by the Invention] As described above, in the related art, a vehicle is garaged by combining the fixed route guidance method and the point-to-point guidance method. In guiding the vehicle, the trajectory of the vehicle often draws a curve, and there is a problem that the parking position greatly varies due to the variation in the difference between the inner and outer wheels of the vehicle and the variation in the Ackerman set value.

The present invention has been made in view of the above conventional problems,
It is an object of the present invention to provide an automatic parking device that minimizes the distance traveled by a curve, eliminates variations due to differences in inner and outer wheels, and enables a vehicle to be securely and smoothly parked in a garage.

[Means for Solving the Problems] To achieve the above object, an automatic parking device according to the present invention includes a sign sensor provided at a predetermined position of a vehicle, and a garage of the vehicle based on a detection signal from the sign sensor. First calculating means for calculating a relative position with respect to the vehicle, second calculating means for calculating the approach center line of the garage to be parked and the front-rear center line of the vehicle from the calculated relative position, and the calculated approach center of the garage. A third calculating means for calculating a line and an arc inscribed in the front-rear center line of the vehicle, and a vehicle in accordance with one of the front-rear center line of the vehicle, the inscribed arc, and the entrance center line of the garage according to the relative position. And control means for controlling the steering angle of the vehicle so as to travel.

[Operation] The automatic parking device of the present invention has such a configuration, and in the trajectory of the vehicle when entering the garage, the curved portion is limited to an arc inscribed in the vehicle front-rear center line and the garage approach center line. Is what you do.

That is, the longitudinal center line of the vehicle and the approach center line of the garage are determined from the relative positions calculated by the detection signals from the sign sensors, and the arc inscribed in these two straight lines is determined from the geometric theorem.

Then, the trajectory formed by the vehicle front-rear center line, the inscribed arc, and the garage approach center line becomes an approach route with a minimally curved portion, and the control device determines the vehicle front-rear center line, the inscribed arc according to the relative position of the vehicle. By selecting one of the garage approach center lines in order, the vehicle can be surely entered.

Hereinafter, a preferred embodiment of the automatic parking device according to the present invention will be described with reference to the drawings.

FIG. 2 shows the system configuration of this embodiment.
A scanning ultrasonic sensor 12 is provided on the side of the vehicle 10 and detects an obstacle on the side of the vehicle by ultrasonic waves.

On the other hand, behind the vehicle 10, a fixed ultrasonic sensor 14 and a CC
A D-mark sensor 16 is provided to read a sign on the garage position display means 24 such as an obstacle behind the vehicle and a pole provided at a predetermined position in the garage.

The detection signals from these sensors are input to an electronic control unit ECU 18 including an interface I / F, a ROM storing a predetermined program, a CPU performing arithmetic processing according to the program, a RAM storing the calculation results, and the like. A control signal is sent to the steering actuator 20 and the brake actuator 22 based on these detection signals to automatically park the vehicle in the garage.

Here, a characteristic of the present embodiment is that the ECU 18
The relative position of the vehicle is calculated based on the detection signal from the CD sign sensor 16, and the arc inscribed in both the approach center line of the garage and the front-rear center line of the vehicle is calculated, and the front-rear center line of the vehicle, the inscribed arc, the garage are calculated. The traveling control of the vehicle in the order of the approach center line.

Hereinafter, the arithmetic processing performed by the ECU 18 will be described in detail with reference to the principle explanatory diagram of FIG. 1 and the flowchart of FIG.

In FIG. 3, first, at step 100, it is determined whether or not the automatic parking system operation switch is ON. Although not shown in FIG. 2, this system operation switch can be attached to, for example, an instrument panel in a vehicle driver's seat, and the ECU 18 detects this output signal to determine whether it is ON. If this system operation switch is ON, that is, if the vehicle driver approaches the garage and activates the system to automatically park the vehicle, the next step 10
The process proceeds to 2 to determine whether the operation of the system is continued.
As described above, in the present embodiment, an obstacle sensor using ultrasonic waves is provided on the vehicle side and the vehicle rear,
According to the detection signals from these obstacle sensors, (a) when the distance to the garage rear wall is equal to or less than a predetermined set value, (b) when an obstacle is detected within a predetermined range on the side of the vehicle or behind the vehicle. For example, it is determined that the system is interrupted, and a warning is issued to alert the driver (step 104).

On the other hand, if it is determined in step 102 that the system is to be continued, the process proceeds to the next step 106, where it is determined whether or not the initial relative position of the vehicle has already been detected. At the start of the system operation, since the ECU 18 has not yet detected the initial relative position, it is determined to be NO in this step, and the routine proceeds to step 108, where the initial relative position (a, b) and the inclination angle with respect to the garage entrance surface are determined. θ is calculated. In order to calculate the initial relative position (a, b) and the inclination angle θ, for example, if the sign sensor 16 is two CCD cameras or the like provided at regular intervals in the same direction, the obtained image is converted into a binary image. It is possible to detect where the mark of the position display means is located in the image by performing the conversion process, and to calculate from the position, the mounting interval of the CCD camera, the lens focal length and the CCD 1 bit length.

After the initial relative position (a, b) and the inclination angle θ are calculated,
In the next step 110, the turning center (α, β) is calculated.

Hereinafter, the process of calculating the turning center will be described in detail with reference to the principle explanatory diagram of FIG.

FIG. 1 shows an orthogonal coordinate system in which the origin O is set at the center of the entrance plane of the garage, and the x-axis is taken in a direction parallel to the entrance plane and the y-axis is taken perpendicular to the entrance plane.

Then, it is assumed that the vehicle 10 exists at the position of the relative position (a, b) and the inclination angle θ as shown in the figure.

First, the ECU 18 calculates an intersection S between the front-rear center line of the vehicle 10 and the approach center line of the garage, that is, the y-axis in the figure. The front-rear center line of the vehicle can be represented by a straight line having an inclination tan θ passing through the coordinates (a, b), and y−b = tan θ (x−a).

 On the other hand, the garage approach center line is x = 0, so the y coordinate of S is OS = b-atan θ.

Next, an arc inscribed in two straight lines, that is, a vehicle front-rear center line and a garage approach center line, which is a turning locus, is calculated. In the present embodiment, the ECU 18 has a length equal to the OS calculated as described above. Then, a point O 'is set on the front-rear center line of the vehicle, and the point at which the perpendicular bisector of OS and the perpendicular bisector of O'S intersect is calculated as the center of the inscribed circle.

That is, the coordinates of the midpoint M of OS are M (0, OS / 2), and the coordinates of O ′ are O ′ (| OS | cos θ, OS + | OS | sin θ). Further, since the coordinates of M ′ are M ′ (| OS | / 2cosθ, OS + | OS | / 2sinθ), the coordinates of the center O ″ of the circle inscribed in the two straight lines OS and O ′S are obtained from the elementary geometry theorem. (alpha, beta) When, α = OS / 2tanθ + | OS | / 2sinθtanθ + | OS | / 2cosθ = 1/2 {btanθ-atan 2 θ + | b-atanθ | (sinθtanθ + cosθ)} β = 1/2 (b −atan θ) The arc MM ′ of the inscribed circle at this time becomes the turning locus of the vehicle 10 as described later.

Thus, in step 110, the turning center O ″ (α,
After β) is calculated, the vehicle 10 is controlled to travel along these straight lines OS, O'S or the curve MM '. For this purpose, first, in the next step 112, the curve MM' calculated in the next step 112 is used. It is determined whether the vehicle can run according to the following. That is,
It is determined whether or not the calculated radius r = O ″ M (or O ″ M) of the curve MM ′ is equal to or greater than the minimum turning radius r _{min of the} vehicle 10. If NO in this step, that is, if the calculated radius r is _smaller than or equal to the minimum turning radius r _min , the process ends because the vehicle cannot travel along the curve MM ′. If the turning center O ″ (α, β) is below the garage entry plane, that is, β <0, the vehicle 10 cannot enter the garage, so it goes without saying that the process is also terminated in this case.

On the other hand, if YES is determined in the step 112, the process proceeds to the next step 114 to calculate the relative position (x, y) of the vehicle 10. This calculation method can be performed by processing the image obtained by the CCD camera and detecting the position of the marker, similarly to the above-described step 108 in which the initial relative position is calculated.

After calculating the relative position (x, y), the ECU 18 instructs the steering actuator 20 and the brake actuator 22 on how to control the vehicle according to the relative position. That is, first, in step 116, it is determined whether or not the x coordinate of the relative position is smaller than or equal to the x coordinate of M '. If it is determined that the vehicle 10 is on the right side of M' in FIG. At step 118, the steering angle is set to 0 ° and the vehicle 10 moves backward in order to move the vehicle 10 backward along the front / rear center line.

On the other hand, if it is determined in step 116 that the value is equal to or smaller than the x coordinate of M ', that is, if the vehicle 10 is located on the left side of M' in FIG.

In this step 120, it is determined whether or not the y coordinate of the relative position of the vehicle 10 and the y coordinate of M, that is, the y coordinate β of the turning center is equal to or less than NO. If it is determined that the vehicle is on the upper side, the steering angle is controlled so that the vehicle 10 travels along the arc MM ′ calculated in the above-described step 110, and the vehicle 10 moves backward on a curve (step 12).
2).

If YES in step 120, that is, if it is determined that the vehicle 10 is below the turning center O ″, it is determined that the vehicle is already on the approach center line of the garage, that is, on the y-axis in FIG. In this case, the ECU 18 sets the steering angle to 0 ° again, moves backward, and guides the vehicle 10 to the garage (step 124).

Thus, in the present embodiment, the curvilinear movement of the vehicle 10 is limited to only the arc of a circle inscribed in both the vehicle front-rear center line and the vehicle approach center line, and all other routes are guided to the garage as straight roads. By minimizing the curved traveling distance of the vehicle 10, it is possible to minimize variations in parking positions due to variations in inner and outer wheels, and to guide the vehicle smoothly and reliably to the garage.

In the present embodiment, the arc MM ′ in step 112
When the radius r is equal to or smaller than the minimum turning radius r _min , the process is terminated.However, instead of terminating the process in this way, for example, the inclination angle of the vehicle 10 is changed by a command from the ECU 18,
The processing may shift to step 102 again.

[Effects of the Invention] As described above, according to the automatic parking device according to the present invention, there is an effect that the vehicle can enter the garage smoothly and reliably by minimizing the locus of the vehicle drawing a curve.

[Brief description of the drawings]

FIG. 1 is a view for explaining the principle of an embodiment of an automatic parking apparatus according to the present invention, FIG. 2 is a system configuration diagram of the embodiment, and FIG. 3 is a control flowchart in the embodiment. 10… Vehicle 16… Signage sensor 18… ECU

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05D 1/02 B62D 6/00 B62D 113: 00 JOIS

Claims (1)

(57) [Claims] 1. An automatic parking device for automatically parking by detecting a sign provided at a predetermined position of a garage and recognizing a relative position of the vehicle with respect to the garage, comprising: a sign sensor provided at a predetermined position of the vehicle; First calculating means for calculating the relative position based on the detection signal from the sign sensor; and second calculating means for calculating the approach center line of the garage to be parked and the front-rear center line of the vehicle based on the calculated relative position. Third calculating means for calculating an arc inscribed at the calculated garage approach center line and the vehicle front-rear center line; and, based on the relative position, the vehicle front-rear center line, an inscribed arc, and a garage approach. Control means for controlling a steering angle of the vehicle so that the vehicle travels along any of the center lines.