JPH05100029A - Obstacle position detecting device - Google Patents

Abstract

PURPOSE:To evade an obstacle for traveling without indiscriminately stopping when the obstacle is detected in front of a vehicle at no increased cost. CONSTITUTION:Two laser radars 3A, 3B are installed apart by a fixed distance on the front section 6 of a vehicle 2, when an obstacle is detected at the preset distance Lob on the X-axis in the front, the reception characteristics of the laser radars 3A, 3B can be shown by curves mA, mB centering on a point -(a) and a point (a) depending on the position of the obstacle on the X-axis. A fuzzy rule is prepared based on the reception levels shown by mA, mB and the distance from the obstacle, the distances of the obstacle from the point -(a) and (a) are determined, and the distance of the obstacle from the origin 0 is determined based on the distance information and the reception levels mA, mB of two laser radars 3A, 3B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an obstacle position detecting device, and more particularly to an obstacle object position detecting device suitable for being mounted on an unmanned vehicle.

[0002]

2. Description of the Related Art As a conventional device of this type, one shown in FIG. 9 is known. FIG. 1A shows an unmanned vehicle 2
A front view of the vehicle 2 is provided with a camera 4 for taking an image of the front of the vehicle, and a front part of the front portion 6 is near the center of the lower part of the vehicle. The laser radar 3 for detecting the obstacle 5 is provided.

While the vehicle is traveling, the camera 4 photographs the two white lines 1, 1 to guide the vehicle 2 to travel within the two white lines 1, 1 and the laser radar 3 causes the vehicle 2 to travel. When the obstacle 5 is detected at the front L position, the vehicle 2 is automatically stopped to prevent a collision.

[0004]

However, in the conventional device as described above, when the obstacle 5 is detected ahead of the fixed distance L by the laser radar 3, the vehicle 2 is automatically stopped. Since the laser radar 3 can detect only the distance to the obstacle 5 and cannot detect the amount of deviation in the lateral direction of the obstacle 5 (indicated by the arrow A in FIG. 9B), the laser radar 3 bypasses the obstacle 5 and travels. There was a problem that you had to stop uniformly even if you could.

In this case, a large number of laser radars 3 may be provided, and the distances to the obstacles 5 may be detected by measuring the distances to the obstacles 5 by the individual laser radars 3. However, in this case, a large number of laser radars must be provided, which causes a problem of high cost.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide an obstacle position detecting device capable of detecting a lateral shift amount and not costly. To do.

[0007]

In order to achieve the above-mentioned object, the present invention is constructed as shown in the claim correspondence diagram in FIG. 1, is installed at a certain distance in the front part of a vehicle, and is a laser projected in front of the vehicle. A pair of laser radars a and a that detect the distance from the reflected wave of light to the obstacle f, and when the obstacle f is detected a predetermined distance ahead, the reception level of the reflected wave is set to the respective laser radar a and a. Based on the reception level detection means b for each detection, and the reception level of each laser radar a, a detected by the reception level detection means b, using fuzzy inference, the installation position of each laser radar a, a is set as a reference. The first lateral deviation amount calculating means c for calculating the lateral deviation amount of the obstacle f, the reception level of each laser radar a detected by the reception level detecting means b, and the first Lateral deviation amount calculation means c Based on the calculated lateral deviation amount, the second lateral deviation amount calculating means d for calculating the lateral deviation amount of the obstacle f from the vehicle traveling direction center line and the laser radar a, a are detected. The distance to the obstacle and the second above
Obstacle position detecting means e for detecting the position of the obstacle f based on the lateral displacement amount calculated by the horizontal displacement amount calculating means d;
It is characterized by having.

[0008]

According to the present invention, two laser radars for detecting the distance to the obstacle are installed in the front part of the vehicle at a constant distance.

When an obstacle is detected ahead of a predetermined distance by the two laser radars, the reception level at that time is detected by the reception level detecting means for each laser radar, and the first lateral deviation amount is further detected. The computing means computes the lateral shift amount of the obstacle for each laser radar based on the reception level detected for each laser radar, using the fuzzy inference based on the installation position of the laser radar.

In the second lateral deviation amount calculating means, the reception level of each laser radar detected by the reception level detecting means and the lateral level of each laser radar calculated by the first lateral deviation amount calculating means. The lateral deviation amount from the center line of the vehicle traveling direction is calculated based on the deviation amount, and the obstacle position detecting means further detects the lateral deviation amount calculated by the second lateral deviation amount calculating means and the laser radar. The position of the obstacle is two-dimensionally detected based on the distance information to the obstacle.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The same components as those used in the above-mentioned conventional example will be described with the same reference numerals.

FIG. 2 is a schematic diagram showing a schematic configuration of an embodiment to which the present invention is applied. FIG. 2 (a) is a side view of an unmanned vehicle 2 capable of autonomous traveling, and FIG. 2 (b) is a plan view thereof. is there.

First, the structure will be described. A camera 4 for photographing the front is attached near the center of the upper portion of the front portion 6 of the vehicle 2, and a pair of laser radars 3A, 3B ( Laser radars a and a) are attached at a predetermined distance.

While the vehicle is traveling, the vehicle 4 is guided by the camera 4 for photographing the front so as to travel along the white lines 1 and 1, and the obstacle 5 is detected in front by the pair of laser radars 3A and 3B. If it does, stop or make a detour to the left or right.

Next, FIG. 3 is a block diagram showing the electrical construction of the embodiment apparatus shown in FIG.

In FIG. 1, the camera 4 is for photographing the white lines 1, 1 in front of the vehicle (see FIG. 2).
1 calculates the position coordinates of the white lines 1 and 1 and the tangent angle at each coordinate point from the photographing information.

Further, the map information unit 22 stores map information of the traveling route on which the vehicle is traveling, and stores branch point information and the like on the way of the traveling route.

Further, the traveling control section 23 is provided with a map information section 22.
The route to be traveled is determined based on the map information and the information from the laser radars 3A and 3B stored in.

Further, the steering angle control section 24 calculates the steering angle based on the white line information sent from the image processing device 21 and the traveling route information sent from the traveling control section 23.

The steering drive unit 25 drives an actuator (not shown) based on the steering angle information calculated by the steering angle control unit 24 to perform steering operation.

The above is the configuration of this embodiment, but when the obstacle 5 is detected in front of the vehicle next time, the traveling control unit 23 is used.
The processing procedure executed by will be described with reference to the flowchart shown in FIG.

First, while the vehicle is traveling, the two laser radars 3
The obstacles ahead of the vehicle are detected by A and 3B. If the obstacle 5 is detected ahead of the vehicle, the distances LA and LB to the obstacles 5 by the two laser radars 3A and 3B are detected.
Is started (step 400), and it is checked whether or not the distance between the vehicle 2 and the obstacle 5 in front is close to a predetermined value Lob (step 402).

This will now be described with reference to FIG. 5. A pair of laser radars 3A and 3B are located at predetermined positions a away from the center P of the front portion 6 of the vehicle 2 in the vehicle width direction.
Based on the distances LA and LB from the laser radars 3A and 3B to the obstacle 5 in front of the vehicle, (L
With A + LB) / 2 as the distance to the obstacle 5, it is examined whether or not this value has approached a predetermined value Lob.

When it is detected that (LA + LB) / 2 = Lob (YES in step 402),
Next, the reception levels mA and mB of the laser radars 3A and 3B at that time are detected (step 404). This corresponds to the reception level detecting means in claim 1.

By the way, FIG. 5 shows the reception level mA detected by the laser radar 3A and the reception level mB detected by the laser radar 3B. The detected reception level m is the laser radar 3A, It is represented by a normal distribution having a peak value at the front position of 3B (indicated by -a and a in the figure). This is because in laser radar, the azimuth resolution of the sensing directional curve is affected by noise.

Therefore, as shown in FIG. 6, the lateral displacement amount x of the obstacle 5 viewed from each laser radar 3A, 3B is
x | = f (M) (where M = mA / α or mB / α
Where α is a constant), the nonlinear function is further divided into fuzzy sets as shown in FIG. 7, and the step x is to detect the lateral shift amount x of the obstacle by using fuzzy reasoning. The processing is 406 and below.

The lateral shift amount x of the obstacle is expressed by a function as shown in FIG. 6, but this function cuts the reflected wave at a constant threshold level in a general laser radar device, for example. Can be made variable or can be obtained by adjusting the constant α.

Further, although divided into fuzzy set as shown in FIG. 7 is a function shown in FIG. 6 (membership functions), which is the reception level M and the deviation amount | x | a S ₀ has a plurality of labels, respectively - It is divided into fuzzy functions of S ₆ and T _{o to} T ₆ .

Then, for example, if M = Si then | x | is Tj (where i = 0 to 6, j = 0 to 6) is created, a well-known MINI-M is created.
The deviation amount | x | is to be obtained by the AX method.

That is, the two laser radars 3A and 3B
When a reception wave of reception levels mA and mB is detected from
= MA / α or mB / α, the reception level mA, m
A rule having B as an input value is selected from prepared rules, and output values RA (n) and RB (m) for each rule are obtained (step 406).

Then, the calculated output values RA (n), R
The weighted weighted average values (xA) and (xB) are obtained from B (m) by the MINI-MAX method, and the deviation amount | x | is set (step 408). The above steps 406 and 408 correspond to the first lateral deviation amount calculating means in claim 1.

The above is the calculation process of the displacement amount | x | of the forward obstacle with reference to the installation position of each laser radar 3A, 3B using fuzzy inference.
Only the absolute value of the shift amount from a and the position based on a is obtained, and it is not known which of the shift amount is on the left and right.

Therefore, in the following processing, the reception levels mA, m detected by the two laser radars 3A, 3B
Whether the amount of deviation is right or left is determined according to the magnitude of B, and the lateral deviation x of the obstacle is detected.

That is, as shown in FIG. 5, when the point in front of the distance P from the center P of the vehicle 2 is the origin 0 and the center line in the vehicle traveling direction is PO, the lateral shift amount x from the origin 0 is as follows. Required.

That is, first, it is checked whether or not mA> mB (step 410). (1) If mA> mB and mB = 0 (steps 410, 4)
12 and YES), x = -a- | xA | (step 414), and (2) if mA> mB and mB ≠ 0 (Y at step 410).
ES, No at step 412), x = −a + | xA | (step 316), and (3) if mA ≦ mB and mA ≠ 0 (steps 410, 4).
No in 18) and x = a− | xB | (step 420). (4) If mA ≦ mB and mA = 0 (N in step 410)
o, YES at 418), x = a + | xB | (step 422). The above steps 410 to 422 are the second in claim 1.
Corresponds to the horizontal deviation amount calculation means.

In this way, when the lateral shift amount x of the obstacle centered on the center line PO of the vehicle is detected, the position of the obstacle can be obtained at coordinates (x, Lob) (step 424). .. This step 424 corresponds to the obstacle position detecting means in claim 1.

Next, in FIG. 8, the lateral shift amount x is set as described above.
Shows the travel route of the vehicle 2 when the obstacle 5 is detected at the position of the front Lob of the vehicle 2.

That is, in this case, if the center line in the traveling direction of the vehicle 2 is PO and the point on the x-axis which is a certain distance d from the origin 0 as a center is d, d, the steering angle control unit 24
If (1) x <-d, avoid the R1 route on the right, (2)
If x> d, avoid the left route R2, (3) -d ≦ x ≦ d
Then, a signal is output to the steering drive unit 25 so as to stop without steering.

As the steering angle control section 24, for example, steering angle calculation means described in Japanese Patent Laid-Open No. 64-7110 is used.

As described above, the apparatus of this embodiment uses the two laser radars 3A and 3B, and when the obstacle 5 is detected ahead of the predetermined distance Lo, fuzzy inference is performed from the reception level of the received wave at that time. Vehicle center line P of obstacle 5
Since the lateral deviation amount from O is calculated and the plane coordinate position of the obstacle 5 is detected by this, not only the distance information to the obstacle 5 but also the azimuth information can be known.

Therefore, when an obstacle is detected ahead, not only can it be stopped uniformly as in the conventional case, but it is also possible to avoid the obstacle and make detours to the left and right, enabling more efficient traveling to the destination. Have an effect.

Further, since the lateral displacement amount of the obstacle can be detected by only two laser radars, this type is low in cost as compared with the method of detecting the lateral displacement amount by combining a large number of laser radars. There is also an effect that the device can be obtained.

In this embodiment, the distance to the obstacle is detected by using the laser radar, but it goes without saying that a distance measuring device such as a radio wave radar or an ultrasonic sensor can be used.

[0044]

As described above, according to the present invention, 2
The position of the obstacle in front is detected two-dimensionally by using fuzzy reasoning from the reception level of the distance information using the laser radar of one unit, so even if the obstacle is detected in the front, it is uniform. You can also choose to detour to the left or right without stopping, and you can run more efficiently even when installed in an unmanned vehicle.

Since only two laser radars are provided, this type of device can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of an embodiment to which the present invention is applied.

FIG. 3 is a block diagram showing an electrical configuration of the embodiment shown in FIG.

FIG. 4 is a flowchart illustrating the operation of the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a case where two laser radars are installed and the reception level of a received wave from an obstacle is detected for each laser radar.

FIG. 6 is a characteristic diagram showing a relationship between a reception level of a received wave and a lateral shift amount.

7 is an explanatory diagram when the characteristic diagram shown in FIG. 6 is divided into fuzzy functions.

FIG. 8 is an explanatory diagram showing a vehicle traveling method when an obstacle is detected ahead.

FIG. 9 is a schematic diagram showing a schematic configuration of this type of device in a conventional example.

[Explanation of symbols]

 a laser radar b reception level detecting means c first lateral deviation amount calculating means d second lateral deviation amount calculating means e obstacle position detecting means f obstacle 1 white line 2 vehicle 3A, 3B laser radar 4 camera 5 obstacle 6 Front part 31 Image processing device 32 Map information part 33 Travel control part 34 Steering angle control part 35 Steering drive part

Claims (1)

[Claims] 1. A pair of laser radars installed at a front portion of a vehicle at a predetermined distance to detect a distance to an obstacle from a reflected wave of laser light projected to the front of the vehicle; and the obstacle is detected at a predetermined distance forward. In this case, the reception level detecting means for detecting the reception level of the reflected wave for each laser radar and the reception level for each laser radar detected by the reception level detecting means are used for each laser radar using fuzzy inference. A first lateral deviation amount calculating means for calculating a lateral deviation amount of an obstacle with reference to the installation position of the laser, a reception level for each laser radar detected by the reception level detecting means, and the first Second lateral deviation amount calculating means for calculating the lateral deviation amount from the vehicle traveling direction center line of the obstacle based on the lateral deviation amount calculated by the lateral deviation amount calculating means, and the laser radar detecting An obstacle position detecting means for detecting the position of the obstacle based on the predetermined distance to the obstacle and the lateral shift amount calculated by the second horizontal shift amount calculating means. Obstacle position detecting device.