JPH04167008A - Vehicle position detection device - Google Patents

Abstract

PURPOSE:To obtain highly accurate position data by finding the position of a vehicle relative to a carport by triangulation from the phase difference generated between the image formation positions of a 1st and a 2nd CCD sensor owing to the distance between the optical axes. CONSTITUTION:The detection device is equipped with the 1st and 2nd CCD sensors 14 and 16 which photograph markers 104 and 106 through 1st and 2nd lenses 22 and 23 and an arithmetic means 28 which calculates the relative position (x, y) and azimuth angle phi to the carport with the detection signals according to equations I - IV. In the equations I - IV, m1 and m2 are the image formation positions of the 1st and 2nd indicators on the 1st CCD sensor 14, n1 and n2 the image formation positions of the 1st and 2nd indicators on the 2nd CCD sensor 16, DELTAx the element length of the 1st and 2nd CCD sensor 16, (f) the focal length of the lenses, L the distance between the 1st and 2nd indicators, and D the distance between the optical axes of the 1st and 2nd CCD sensors 14 and 16. Consequently, the vehicle position detection device which can measure a distance with high accuracy and applicable to an automatic parking device is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a vehicle position detection device applied to a car parking device, in particular, a device for photographing a sign installed at a predetermined location of a garage, such as at the entrance, using a CCD sensor. The present invention relates to a device for detecting the relative distance and relative direction of a vehicle to a garage.

[Prior Art] Conventionally, a device is known that detects a sign such as a pole provided at a predetermined position in a garage, and automatically parks the vehicle in the garage while detecting the relative position of the own vehicle with respect to the garage. Such automatic parking systems require technology to detect the position of the own vehicle with high precision, and for this reason, various vehicle position detection devices have been developed.

As an example of such a vehicle position detection device,
There is a vehicle guidance system with an autopilot device disclosed in Japanese Patent No. 20308. In this system, the vehicle is equipped with a reflective sensor that emits a signal to a reflector installed on the ground side and detects the reflection of this signal, and based on the signal from this reflective sensor, the vehicle's relative position relative to the reflector is determined. It detects the position.

[Problem to be solved by the invention] However, with this configuration in which the relative position of the vehicle is calculated by emitting a signal and receiving the reflected signal from the reflector plate, sufficient positional accuracy cannot be obtained. There was a problem that the values varied greatly.

In other words, the signal emitted to the reflector may be, for example, laser light or ultrasonic waves, but light (electromagnetic waves)
The propagation speed of ultrasonic waves is high, making it difficult to measure short and medium distances (distances in this range are a problem for automatic parking systems), and although the speed of ultrasonic waves is smaller than that of light, it lacks directivity, etc. The problem is that it is difficult to perform accurate distance measurement over a wide area, and the error in position detection is 8 degrees, causing the parking position to shift, and in the case of a narrow garage, it may become impossible to park. Put it away.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to enable highly accurate distance measurement over a wide range,
An object of the present invention is to provide a vehicle position detection device applicable to an automatic parking device.

[Means for Solving the Problems] In order to achieve the above object, the vehicle position detection device of the present invention detects the first and second signs provided at predetermined positions in the garage.
and a first and second CCD sensor that takes an image through a second lens, and a calculation that calculates a relative position (x, y) and azimuth angle φ with respect to the garage based on the following formula based on the detection signals from these first and second CCD sensors. It is characterized by having means.

t, anφ−Δx/f ・(m2nL−m1n2)bm
2-al+n2-n1)x-D 2firΔx ・(I
112-m1)/(ml+n1)(a+2+n2)y-
Dr (Δx/D2・l(m2−m1)+(n2−
n1) 13(Δx#) (m2nL-m1n2)l
/(a+1n2)}/(m1+n1)(m2+n2)
2IIl: Imaging position of the first label on the M1ccD sensor m2: Imaging position of the second label on the first CCD sensor nl: Imaging position of the first label on the second CCD sensor n2: Imaging of the second label on the second CCD sensor Position Δx: Element length f of the first and second CCD sensors: Focal length of the lens L: Distance between the first and second marks D: Distance between the optical axes of the first and second CCD sensors [Function: Vehicle position detection of the present invention The device has such a configuration and passively detects the vehicle position using a CCD sensor instead of a reflective sensor.

That is, the first and second CCD sensors
When a sign is photographed, a phase difference occurs in the imaging position due to the position and orientation of the sign, as well as the distance between the optical axes of the first and second CCD sensors. From this phase difference, the position of the vehicle relative to the garage can be determined using the principle of triangulation. By calculating this, highly accurate position data can be obtained.

[Embodiment] Hereinafter, a preferred embodiment of the vehicle position detection device according to the present invention will be described with reference to the drawings.

FIG. 2 shows a block diagram of the configuration of the vehicle position detection device in this embodiment. The vehicle position detection device of this embodiment includes a main body section 10 and a signal processing section 12. Main body part 10
includes a first CCD line sensor 14 and a second CCD line sensor 16, which are arranged on a horizontal plane with a distance equal to the distance between the optical axes, and are attached to a predetermined position of the vehicle, for example, at the center of the rear part. Figure 3 shows the first CCD line sensor 1.
A perspective view of the main body 1° including the 4 and M2 CCD line sensors 16 is shown, and FIG.
A configuration diagram of a line sensor is shown.

As shown in FIG. 3, the first CCD line sensor 14
and the second CCD line sensor 16 are in the same plane (horizontal plane)
The motor 18 is mounted perpendicularly to the rotating shaft of the motor 18 at a distance D apart from the motor 18, and is configured to be freely rotatable in a horizontal plane. An encoder 20 for detecting the rotation angle of the motor 18 is attached to the rotation shaft of the motor 18, and is used as a parameter for correcting the azimuth angle of the vehicle with respect to the garage, as will be described later.

Further, as shown in FIG. 4, the first and second CCD line sensors 14 and 16 each have condensing lenses 22 and 23.
It is placed inside a container 24.25 attached to a garage, and collects light from a sign such as a pole installed at the garage entrance.
This is a configuration that forms an image.

On the other hand, the signal processing section 12 of this device includes an A/D converter 26 that converts analog detection signals from the first CCD line sensor 14 and the second CCD line sensor 16 into digital signals;
It includes an electronic control unit ECU28 that performs predetermined arithmetic processing,
The ECU 28 detects the relative position of the vehicle with respect to the garage based on the detection signal and supplies a control signal to actuators 30 such as a steering actuator and a brake actuator to park the vehicle in the garage.

The vehicle position detection device of this embodiment has such a configuration, and the position detection calculation process performed by the ECU 28 will be described in detail below.

FIG. 1 shows the positional relationship between a vehicle 100, a garage 102 where the vehicle 100 is to be parked, and two signs 104 and 106 provided at the entrance of the garage 102. Barcodes may be attached to these signs 104 and 106,
It is also possible to use a sign that emits light using an LED, a laser, or the like.

In this FIG. 1, the front and rear center line of the vehicle 100 and the garage 10
The intersection point with the straight line parallel to the entrance surface of 2 is A12 signs 1
04.B is the location where 106 is installed.

The foot of the perpendicular drawn from the center of gravity O of the C1 vehicle 100 to a straight line parallel to the entrance surface of the garage 102 is D, and ZOAD-φ,
Assuming that 0D-x and CD-y, the relative position of the vehicle 100 with respect to the garage 102 can be determined by determining (x, y) and φ.

Now, when finding these physical quantities, fAOB-θ, Z
Assuming AOCm-θ3 and BO b1CO-c, as shown in the figure, in ΔOBC, b/5in(φ+θa) ”C/stn(φ+θ
2) -L/5in (θ3-θ2)
...(1) holds true. However, L is the distance between the two markers 104 and 106. Also, in ΔAOC and ΔAOB, (L+AB)/s inθ -c/s'+nφ
−= ・−(2) b/mountain φ=AB/mountain θ2 ・
...(3) In ΔODC, 1! n(φ103)・x/7 ・・・・・・
(4) In △ODB, tan (φ10θ) ・x/(L+y) +
+++++ Since (5) holds true, the following relationship is derived from these equations.

tanφ−(csinθa−bsinθ2)/(bC
O502-CCO'Sθ3) ・・・・・・
(6) x=csin (φ + θ3) =
bsin (φ+θ2)... (7) Y=xz'1an(φ+θ3) (8) In this way, the parameters (x, y
) and φ are the distances from the vehicle 100 to each of the signs 104 and 106, c and the azimuth angle θ2 with respect to these signs 104 and 106. determined by θ3 and thus these physical ff1b,c.

θ2. By determining θ3, the relative position of vehicle 100 can be determined.

Below are 100 vehicles and 2 markers! The process of calculating the relative distance and relative direction to 104 and 106 will be explained.

FIGS. 5A and 5B show output characteristics when two markers 104 and 106 are photographed by the first and second CC and D line sensors 14 and 16.

In the figure, the dashed and dotted lines indicate the optical axis of each sensor.
Images of the marks 104 and 106 can be easily detected if they are emitted by, for example, an LED or a laser, since a peak appears at that part. In the case of Fig. 5, the peaks 108 and 110 correspond to these label images, and the deviations from the optical axis are respectively: 1st CCD line sensor 14 label 104: ml label 106·m2 2nd CCD line sensor 16 label 104: nl mark ! 106:n2.

In addition, in order to obtain the deviation of each marker image 108, 110, the sixth
As shown in the figure, if the addresses from the optical axis of the CCD element that have a predetermined threshold level of 7 or higher are α and β, then the average can be obtained by (α + β)/2.

In this way, the first and second CCD line sensors 14.1
Two markers 104 and 106 are photographed at 6, and are photographed at different positions ml and m due to the phase difference caused by the distance between the optical axes of these first and second CCD line sensors 14 and 16, respectively.
2. n1. Whether a label image is formed on n2, the deviation ml of the imaging position due to this phase difference, m2. By using nl and n2, the distance and direction from the vehicle 100 to the signs 104 and 106 are calculated.

FIG. 7 shows the positional relationship between the condenser lenses 22, 23, the first and second CCD sensors 14, 16, and the markers 104, 106. In this figure, condenser lenses 22 and 23
The focal length of f1 is the first and second CCD line sensor 14.
, 16 is defined as Δx, tinθ2−m1Δx/′[・・・・・・(9)b=D
I/ΔICO5θ2 (ml +n1) --
(10) tanθ3=m2ΔI/I...
...(11) c=DI/ΔxCO5θ2 (m2+
m2) --(12) holds true. In this way, the relative positions of the vehicle 100 and the signs 104 and 106 are CC
Since it is determined by the imaging position ml, m2゜nl, n2 of the sign 104, 106 in the D line sensor, the relative position of the vehicle 100 with respect to the garage 102, that is, the relative coordinates (x, y) and azimuth φ, are determined by the above-mentioned (6)-(8
), tan φ−Δy, /f ・(m2nl−m1n2
)/(+++2-m1+n2-n1)・・・・・・(
13) x=D 2r/fΔx ・(m2-m1)/(m1n2
)}/(m1+n1)(m2+n2)・・・・・・(
14) rD 2r 2/L(Δx/f')2・((m2
-m1)+(n2-n1)-13(Δx#)2 (a+
2nl-a+In2)lbam1n2)}/(m1+n1
)(m2+n2) 2... (15), and the relative position with respect to the garage 102 can be found from the imaging position of the signs 104 and 106.

Then, based on this relative position (x, y) and φ, the ECU 2
g supplies a control signal to the actuator 30, thereby making it possible to reliably park the vehicle 100 in the garage 102.

As described above, in this embodiment, the relative position of the vehicle with respect to the garage is calculated by detecting the phase difference between the signs imaged on two CCD sensors. There will be times when it will not be possible to take pictures. Considering such a case, in this embodiment, as described above, the first and second CCD line sensors 14,
16 is configured to be rotatable in a horizontal plane by a motor 18, and can detect the two markers 104 and 106. By rotating the sensor, it is possible to detect the position of the vehicle. In this case, if the rotation angle detected by the decoder 20 attached to the rotating shaft of the motor 18 is ω, then θ2. θ3. If Φ is the detection angle during ω rotation, the relative position of the vehicle can be detected using the same calculation formula by correcting as θ3−θ3−ω θ2 θ2−ω φ−Φ−ω.

Furthermore, as described above, in this embodiment, when calculating the relative position of the vehicle, the distances c and c between the vehicle 100 and the signs 104 and 106 are calculated, but as shown in FIG. Between the image position n and the vehicle-sign distance 1 is n-fD/J! Since there is a relationship between can.

[Effects of the Invention] As explained above, the vehicle position detection device according to the present invention can detect the relative position of the vehicle with respect to the garage with high accuracy, and therefore, when applied to an automatic parking system, Reduces variations in vehicle parking position when parking in the garage,
This has the effect of significantly improving system reliability.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of a vehicle position detection device according to the present invention, Fig. 2 is a block diagram of the configuration of the embodiment, Fig. 3 is a perspective view of the device in the embodiment, and Fig. 4 is the same. A configuration diagram of a CCD line sensor in the embodiment, and FIGS. 5 to 8 are illustrations for explaining relative position detection in the embodiment. 10... Main unit 12... Signal processing unit 14... First CCD line sensor 16-= Second CCD line sensor 22... Condensing lens 23... Condensing lens 28... ECU

Claims (1)

[Claims] First and second CCD sensors that photograph first and second signs provided at predetermined positions in a garage through first and second lenses, and detection signals from these first and second CCD sensors. The relative position (x, y) and azimuth angle φ with respect to the garage are determined by tanφ=Δx/f・(m2n1−m1n2)/(m2
-m1+n2-n1)x-D^2r/fΔx・(m2-
m1)/(m1+n1)(m2+n2)y=D^2f^
2/L(Δx/f)^2・{(m2-m1)+(n2-
n1)-m3(Δx/f)^2(m2n1-m1n2)
}/(m1+n1)(m2+n2)^2m1: 1st CC
Image formation position m2 of the first mark on the D sensor: Image formation position n1 of the second mark on the first CCD sensor: Image formation position n2 of the first mark on the second CCD sensor: Image formation position Δx of the second mark on the second CCD sensor : Element length f of the first and second CCD sensors: Focal length L of the lens: Distance between the first and second markers D: Computing means for calculating from the distance between the optical axes of the first and second CCD sensors; Features of vehicle position detection device.