JPH01293410A - Method for detecting obstacle of autonomous type moving vehicle - Google Patents

Abstract

PURPOSE:To surely detect an obstacle in the travelling channel of a moving vehicle by rotating a rotating stand provided at the upper part of the moving vehicle at the time of travelling, and sensing the circumference of the moving vehicle by an optical distance detecting sensor fitted to the rotating stand by inclining the detection direction in the direction lower than the horizontal surface. CONSTITUTION:Since the detection direction of an optical distance detecting sensor 12 fitted at a rotating stand 10 of the upper part of an autonomous type moving vehicle 1 is inclined in the lower direction, a light from the sensor 12 is also generated in the direction and an angle for a floor surface is held. By rotating the rotating stand 10, the floor surface of the circumference of the moving vehicle 1 is sensed to the sensor, and while the rotating stand 10 is rotated, the moving vehicle 1 is travelled and thus, the floor surface of the travelling direction forward direction of the moving vehicle 1 is successively sensed by the sensor 12. Thus, when an obstacle 13 exists in the forward area of the moving vehicle 1, the sensing position of the sensor 12 is moved in the upper direction in the sequence from the lower part of the obstacle 13, and therefore, the obstacle 13 is detected stereoscopically and three- dimensionally by the sensor 12.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an autonomous mobile vehicle such as a cleaning robot that performs cleaning work while traveling inside a general building. The present invention relates to an obstacle detection method for detecting obstacles in order to drive safely.

[Conventional technology]

Normally, this type of autonomous mobile vehicle uses an optical distance detection sensor to detect the position of the obstacle in order to avoid it when there is an obstacle in the travel route that prevents the vehicle from traveling straight. , for example, the magazine "Measurement and Control" (Part 2)
6, No. 2, 1984-110).

In this method of detecting obstacles using distance detection sensors, when light emitted from a light source such as a light emitting diode (LED) or a semiconductor laser hits an object (obstacle), it is diffusely reflected, so the reflected light is sent to a semiconductor device detection element. This is a method of detecting an object by receiving light with a light receiving element such as (PSD), and the distance to the object where the diffused reflection occurs varies depending on the distance where the diffusely reflected light hits the light receiving element. It is calculated using the principle of triangulation.

By the way, when such an optical distance history detection sensor is mounted on the moving vehicle, it is customary to integrate the light source and the light receiving element. Since it is emitted, only -dimensional detection can be performed,
In order to detect an obstacle in the front area, which is the traveling direction of the moving vehicle, it is necessary to scan and sense the detection direction of the sensor.

For this reason, conventionally, as shown in FIGS. 7 and 8,
A turntable CB) is provided on the upper part of the autonomous mobile vehicle (A), an optical path and an elegance detection sensor (C) are attached to the turntable CB),
The moving vehicle (A) is detected by the sensor (C) by rotating the turntable CB).
).

In this case, the detection direction of the sensor (C) is set horizontally in order to quickly detect obstacles existing in the area in front of the moving vehicle (1).

[Problem to be solved by the invention]

However, when detecting obstacles using conventional methods, sensors (
C) The information obtained by 1ζ is limited to fζ on one horizontal plane (D) scanned by the sensor (C), and as shown in FIG. has serious drawbacks that make it undetectable.

Furthermore, as shown in Fig. 8, in the case of an obstacle (CF) that spreads out at the bottom, the presence of the obstacle (F) can be detected by scanning the sensor (C), but the obstacle cannot be detected from the moving vehicle (A). Detection of the distance to the object (F) is also limited to distance measurement on the horizontal plane CD), and the distance g[x from the moving vehicle (A) to the obstacle (F) is detected, but in reality it is In many cases, the distance t2 is quite short, and depending on how the moving vehicle (A) is controlled, it may not be possible to avoid the obstacle CF).

The present invention has been made in consideration of such problems of the conventional technology, and its purpose is to provide an obstacle detection system that can three-dimensionally detect obstacles using an optical distance detection sensor. It is intended to provide a method.

[Means to solve the problem]

In order to achieve the above object, in the obstacle detection method for an autonomous mobile vehicle according to the present invention, the upper part f of the autonomous mobile vehicle is
ζ A rotary table having a rotation axis in a vertical direction is provided, an optical distance detection sensor is attached to the rotary table so that the detection direction of the sensor is inclined downward from a horizontal plane, and the moving vehicle is run while rotating the rotary table. The present invention is characterized in that the sensor detects the obstacle three-dimensionally.

[Effect]

The optical distance detection sensor installed on the rotating platform at the top of the autonomous vehicle is tilted downward in the detection direction, so the light from the sensor is also emitted in this direction, making it at an angle to the floor. It turns out.

By rotating the rotary table, the sensor senses the floor surface around the vehicle, and by rotating the rotary table and driving the vehicle, the sensor senses the floor surface in front of the vehicle in the traveling direction. are sensed sequentially.

Therefore, if there is an obstacle in the area in front of the moving vehicle,
Since the sensing position of the sensor moves upward from the bottom of the obstacle, the obstacle is detected three-dimensionally, that is, three-dimensionally, by the sensor.

〔Example〕

Next, an embodiment of the present invention will be explained using FIGS. 1 to 6.

First, FIGS. 1 to 4 showing a first embodiment will be explained.

Figure 2 shows the schematic configuration of the autonomous mobile vehicle (1),
The vehicle body (
2) Support it so that it can be moved freely.

C (7) The left and right driving wheels (3a) and (3b) are individual f-coats.
E: -9 (5a), (5b) Motors (5a), (5b) (7) Encoders (6a) + (6')) rotated by tv and connected to the rotating shafts (6') + Driving wheels (3a) , (3b) is detected, and the control device (7
) to control the driving wheels (5a) and (5b).
3a).

(3b) By controlling the number of rotations, the vehicle is configured to control travel.

Here, if the rotational speeds of the driving wheels (3a) and (3b) are made the same, the moving vehicle (1) will move straight ahead, and if the rotational speed fζ of each is given, the moving vehicle (1) will rotate0 (8) QG is a sensor motor disposed at the center of the upper part of the vehicle body (2) and equipped with a vertical rotating shaft (9), and QG is disposed on the upper surface of the vehicle body (2) so as to cover the upper surface. 9
), and 0°C is the rotational position of the sensor motor (8), that is, the rotation position of the rotating table (9).
) is a single-use encoder that detects the rotational position of the motor.

(6) is an optical distance detection sensor installed on the conical surface of the rotary table GO with the detection direction inclined downward from the horizontal plane along the inclination of the conical surface, and is a so-called optical sensor. The light receiving element is integrally equipped with -ζ, and the light from the sensor aυ is set to have an acute angle with respect to the floor surface, and the rotation of the rotating platform (ζ, therefore, the floor surface around the moving vehicle (1) is to scan.

Then, when detecting an obstacle, the moving vehicle (1) is run while rotating the turntable qCJ, and at this time,
Since the rotational position of the turntable OQ, that is, the sensing position of the optical sensor (6), is grasped by the signal from the encoder aυ in the control device (7), the position and shape of the obstacle in front of the moving vehicle (υ in the traveling direction) is determined by the control device (7). is correctly detected by the control device (7).

FIG. 3 shows the state of detection in the height direction of an obstacle (rectangular shape) C13 existing within the traveling route of the mobile vehicle (1).

As shown in (a) of the same figure, when the distance between the moving vehicle (1) and the obstacle entrance is large, the light from the optical sensor (2) will pass through the obstacle Q.
3 and hits the floor surface 04), and the reflected light (2) does not return to the optical sensor (2), so the moving vehicle (υ) determines that there is no obstacle Q3 in front of it.

In the same figure (b), the moving vehicle (υ) approaches the obstacle (131ζ), and the light from the optical sensor (2) reaches the lower part of the obstacle opening, and the obstacle (13f) approaches the obstacle (131ζ). The reflected light is received by the optical sensor □□□, and the existence of the obstacle opening and the distance to the obstacle opening are detected.

Figure (C) shows a state in which the moving vehicle (1) is closer to the obstacle αJ than in the state shown in Figure (b), and the light from the optical sensor Q is always at a constant angle with respect to the floor surface. Because
The position at which the light hits the obstacle α1 is higher than in the case shown in FIG. 3B, and the presence of the obstacle opening and the distance to the obstacle C13 at this time are detected.

In the same figure (d), the moving vehicle (1) has further progressed and approached the obstacle σJ, and the light from the optical sensor α2 has passed through the obstacle opening, and the reflected light is reflected from the optical sensor a2t.
Since it does not return, the depth of the obstacle σJ can be determined from this.

In this way, by running the moving vehicle (1) while rotating the turntable GO on which the optical sensor (a) is attached, information on the existence of the obstacle σ4 and its height direction and the obstacle (13 The distance to the obstacle can be detected, and the moving vehicle (1) is controlled to avoid the detected obstacle opening from the state shown in FIG.

FIG. 4 shows how the optical sensor 01 described above detects the obstacle opening in the lateral direction.

This is a case where there is an obstacle Q9 with a convex surface facing the moving vehicle (1) in front of the moving vehicle (1) in the traveling direction. indicates the position where the light hits the floor surface, and (Y) indicates the position where the light from the optical sensor (12) hits the obstacle α.

The optical sensor qz is the optical sensor (6) that hit the obstacle (19).
Since only the reflected light from the obstacle is received, the shape of the diagonal line (Y), that is, the shape of the surface facing the obstacle a (1) (ζ) is detected.

This shows that no matter what shape the obstacle 09 has, it is possible to determine the shape of the surface facing the moving vehicle (1), and in addition to detecting the height of the obstacle as described above. 1ζ Being able to detect obstacles three-dimensionally, that is, three-dimensionally.

Next, a description will be given of FIGS. 5 and 6 tζ showing the second and third embodiments, respectively.

First, in the embodiment shown in FIG.
Vertical rotation axis (9) on the top of the car body (2)! Therefore, the optical sensor (2) is mounted on the rotating conical surface so that its detection direction is inclined downward from the horizontal surface along the inclination of the conical surface.

In addition, in the embodiment shown in FIG. 6, an optical sensor (6) is mounted on the upper surface of the vehicle body (2) in a horizontal direction rotated by a vertical rotating shaft (9), and its detection direction is inclined downward from the horizontal plane. It was installed to do so.

〔Effect of the invention〕

As explained above, according to the obstacle detection method for an autonomous mobile vehicle of the present invention, when the autonomous mobile vehicle is traveling, the rotating table provided at the top of the mobile vehicle is rotated, and the rotating table fζ detection direction is set. Since the optical distance detection sensor installed tilted downward from the horizontal plane senses the surroundings of the moving vehicle, it is possible to reliably detect obstacles in the moving route of the moving vehicle, and also to detect obstacles It is possible to detect obstacles three-dimensionally and accurately grasp the position and shape of obstacles, so even in the case of obstacles that spread out at the bottom, it is possible to control the movement of a moving vehicle while reliably avoiding the obstacles. It is.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the obstacle detection method for an autonomous mobile vehicle according to the present invention, and FIGS.
1 and 2 are schematic side views and plan views of a moving vehicle, and FIGS. 3(a) to 3(d) are diagrams for explaining the detection situation of obstacles in the height direction, respectively. 4 is a plan view for explaining the detection situation of obstacles in the lateral direction; FIGS. 5 and 6 are schematic side views of the mobile vehicle showing other embodiments; and FIG. 8 and 8 are side views for explaining the conventional detection method, respectively. (1)...autonomous mobile vehicle, (9)...rotation axis, QG
, QO, GO... Turntable, (2)... Light sensor, head, 09... Obstacle.

Claims (1)

[Claims] (1) An obstacle detection method for an autonomous mobile vehicle that detects the position of an obstacle on a travel route using an optical distance detection sensor and autonomously travels while avoiding the obstacle, wherein a vertical line is placed above the mobile vehicle. a rotary table having a rotation axis in the direction, the distance detection sensor is mounted on the rotary table so that the detection direction of the sensor is inclined downward from a horizontal plane, the moving vehicle is run while rotating the rotary table, An obstacle detection method for an autonomous mobile vehicle, characterized in that the obstacle is detected three-dimensionally by a sensor.