JPH11161332A - Obstacle detecting device and automated guided vehicle using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an obstacle detecting device which secure safety between circumferential persons and the vehicle by preventing a human body and an obstacle from being got under the body of the vehicle. SOLUTION: At the external edge part of the body 2 of an automated guided vehicle 1, ultrasonic sensors 81 to 85 are arranged, side by side. The ultrasonic sensors 81 to 85 measure distances to a rod surface at specific sampling intervals. It is judged whether or not there is an obstacle under the body 2 from temporal variation in measured value and mutual differences among the measured values of the ultrasonic sensors 81 to 85.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle obstacle detecting device and an unmanned vehicle.

[0002]

2. Description of the Related Art Conventionally, unmanned vehicles controlled by a program have been used as unmanned vehicles for transporting parts and products at production sites. Application as a service robot for delivering meals and specimens is expanding. As described above, since the unmanned traveling vehicle has advanced to a place close to daily life, higher safety is required for the unmanned traveling vehicle. FIG.
FIG. 2 is a side view showing a conventional unmanned traveling vehicle. 1 in the figure
Is an unmanned vehicle. 2 is the body of the unmanned traveling vehicle 1,
3 is a driving wheel, and 4 is a bumper. The drive wheels 3 are driven by a motor (not shown) built in the vehicle body 2. The motor starts, stops, and accelerates according to a control device (not shown) built in the vehicle body 2 and a program preset in the control device. Controls such as deceleration and steering are performed. In this way, the unmanned traveling vehicle 1 travels on the floor 5 according to the programmed route. The bumper 4 is a structure that surrounds an outer periphery of a lower part of the vehicle body 2 and forms an outer edge of the vehicle body 2. The bumper 4 reduces an impact when the unmanned traveling vehicle 1 collides with a surrounding object, and reduces There is a role to prevent getting caught in the bottom. On the front of bumper 4,
The contact sensor 6 is attached, and when the contact sensor 6 hits something, the unmanned traveling vehicle 1 is stopped to prevent accidents.

[0003]

However, in this prior art, the unmanned traveling vehicle 1 cannot detect the obstacle until the obstacle comes into contact with the contact sensor 6, so that the unmanned traveling vehicle 1 cannot detect the obstacle ahead of the path of the unmanned traveling vehicle 1. When standing, shin 7a of human leg 7
Before the unmanned vehicle 1 stops due to contact with the contact sensor 6, there is a problem that the toe 7 b enters under the bumper 4 and gets caught in the driving wheel 3. Needless to say, the gap between the bumper 4 and the floor surface 5 may be eliminated, but the floor surface 5 has some irregularities and gradients, so the gap is indispensable. In addition, when an obstacle on the floor 5 is rolled under the vehicle body 2 or the driving wheel 3, there is a problem that the unmanned traveling vehicle 1 rides on the obstacle and becomes unable to travel or falls down. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an unmanned vehicle obstacle detection device that prevents the uninhabited vehicle from getting caught in the body of the unmanned vehicle and that keeps the unmanned vehicle safe from surrounding people. It is assumed that. It is another object of the present invention to provide an unmanned vehicle equipped with the obstacle detection device.

[0004]

In order to solve the above problems, the present invention is to arrange a plurality of sensors side by side on the outer edge of the body of an unmanned vehicle.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of an unmanned traveling vehicle showing an embodiment of the present invention. FIG. 1 (a) is a front view, and FIG. 1 (b) is a side view. The basic configuration of the unmanned traveling vehicle 1 will not be described because it is the same as that of the prior art. In FIG. 1, 8
Reference numerals 1, 82, 83, 84, and 85 are known ultrasonic sensors, which are sensors that measure a distance to a detection target. The ultrasonic sensors 81 to 85 are mounted in a line at equal intervals in the width direction of the vehicle body 2 on a portion of the bumper 4 located in front of the vehicle body 2 under the vehicle body 2, that is, toward the floor surface 5. Reference numeral 9 denotes a cone, which is a truncated cone-shaped tube attached to the lower part of the ultrasonic sensors 81 to 85 for improving the directivity of the ultrasonic sensors 81 to 85. The ultrasonic sensors 81 to 85 are connected to a control device (not shown), measure a distance to a detection target at a predetermined sampling cycle,
The result is transmitted to the control device. The control device includes:
Temporal change of the measurement result and ultrasonic sensors 81 to 8
The presence or absence of an obstacle below the bumper 4 is determined based on the difference between the measurement results of Step 5 and Step 5. The rules of the judgment are as follows.

(1) As shown in FIG.
When there is an obstacle 10 on the vehicle, only the measured value 11 of the ultrasonic sensor, for example, the ultrasonic sensor 83, which comes over the obstacle 10 among the ultrasonic sensors 81 to 85 arranged in the width direction of the vehicle body 2 is shown in FIG. As shown in FIG. 2B, when the obstacle 10 is detected, it suddenly changes discontinuously. On the other hand, the measured values of the other ultrasonic sensors that do not detect the obstacle 10 do not change. If the obstacle 10 has a shape smaller than the interval between the ultrasonic sensors 81 to 85, such as a human toe, and the height of the cross-sectional shape changes suddenly, the measured value will always be like this. Change. When such a change in the measurement values of the ultrasonic sensors 81 to 85 is detected, the control device of the unmanned traveling vehicle 1 stops the unmanned traveling vehicle 1 on the spot.

(2) When the unmanned traveling vehicle 1 comes to a place having a step or a gap, the measurement values of the ultrasonic sensors 81 to 85 suddenly and discontinuously change at the same time. When such a change in the measurement values of the ultrasonic sensors 81 to 85 is detected, the control device of the unmanned traveling vehicle 1 stops the unmanned traveling vehicle 1 on the spot.

(3) As shown in FIG. 3 (a), when the unmanned vehicle 1 approaches the inclined floor 5, all the measured values 12 of the ultrasonic sensors 81 to 85 are shown in FIG. 3 (b). As shown in FIG. When the unmanned traveling vehicle 1 enters the inclined floor 5 obliquely, the sensor at one end of the ultrasonic sensors 81 to 85 arranged in the width direction of the vehicle body 2, for example, From the sound wave sensor 81, 8
Since the gradients are detected in the order of 2, 83, 84 and 85, the measured values of the ultrasonic sensors 81 to 85 show a certain difference and change sequentially with a certain time lag. Upon detecting such a change in the measurement values of the ultrasonic sensors 81 to 85, the control device of the unmanned traveling vehicle 1 causes the unmanned traveling vehicle 1 to travel as it is.

(4) As shown in FIG. 4A, when the unmanned traveling vehicle 1 is traveling on a flat, unobstructed floor 5,
The temporal change of all the measured values 13 of the ultrasonic sensors 81 to 85 remains within a certain range and remains almost constant. Further, the difference between the measurement values of the ultrasonic sensors 81 to 85 is also within the range of this variation. The variation is caused by a measurement error of the ultrasonic sensors 81 to 85, some unevenness actually existing on the floor surface, or a vibration of the unmanned traveling vehicle 1, and if it is equal to or less than a certain threshold,
It may be considered that a flat floor surface is detected. Upon detecting such a change in the measurement values of the ultrasonic sensors 81 to 85, the control device of the unmanned traveling vehicle 1 causes the unmanned traveling vehicle 1 to travel as it is.

This embodiment is just one of the embodiments of the present invention. Various applications can be developed without departing from the gist of the present invention. For example, from the sensor readings,
The rules for determining the presence or absence of an obstacle, a step, a gradient, and the like can be modified according to the characteristics of the unmanned traveling vehicle and the conditions of the place where the unmanned traveling vehicle operates. Further, in the present embodiment, the ultrasonic sensor is mounted on the bumper located in front of the vehicle body, but may be directly mounted on the vehicle body, or may be mounted on the side of the vehicle body or on the rear side, or on the side of the unmanned traveling vehicle. The safety of humans approaching from behind can be achieved. Further, the ultrasonic sensors may be arranged on a curve according to the shape of the outer periphery of the vehicle body. In addition, if the ultrasonic sensor is tilted toward the outside of the vehicle body instead of directly below, the obstacle can be detected before entering the vehicle body. Furthermore, it goes without saying that the ultrasonic sensor can be replaced with various sensors such as a sensor using light and a sensor using electromagnetic waves as long as the sensor can measure a distance without contact. It is needless to say that the obstacle detection device of the present invention can be installed in various vehicles irrespective of manned or unmanned operation, automatic operation or manual operation.

[0011]

As described above, according to the present invention, the following effects can be obtained. (1) An obstacle under the vehicle is detected and the vehicle is stopped, so that even if a person inadvertently puts a toe under the vehicle, the person is not caught and hurt. In addition, the vehicle does not run over obstacles, thereby preventing the vehicle from running or falling down. (2) Since the vehicle stops upon detecting that it has reached a step or a place with a gap, it does not collide with a step or fall. (3) Since it can be detected that the vehicle is traveling on a place with a slope, the vehicle is not stopped due to a mistake of the slope as an obstacle.

[Brief description of the drawings]

FIG. 1 is an external view of an unmanned traveling vehicle showing an embodiment of the present invention, in which (a) is a front view and (b) is a side view.

FIGS. 2A and 2B are explanatory diagrams illustrating a principle of detecting an obstacle by an unmanned traveling vehicle according to an embodiment of the present invention. FIG. 2A is a side view, and FIG. It is a graph showing a change.

3A and 3B are explanatory diagrams illustrating a principle of detecting an inclination of a floor by an unmanned traveling vehicle according to an embodiment of the present invention, wherein FIG. 3A is a side view, and FIG. 3B is a diagram of measured values of an ultrasonic sensor. It is a graph showing a temporal change.

FIG. 4 is an explanatory view showing a state in which the unmanned traveling vehicle according to the embodiment of the present invention travels on a flat and unobstructed floor surface;
(A) is a side view, and (b) is a graph showing a temporal change of the measurement value of the ultrasonic sensor.

FIG. 5 is a side view of an unmanned traveling vehicle showing a conventional technique.

[Explanation of symbols]

 1: Unmanned traveling vehicle 2: Body 3: Drive wheel 4: Bumper 5: Floor surface 6: Contact sensor 7: Human leg 7a: Shin 7b: Toe 81, 82, 83, 84, 85: Ultrasonic sensor 9: Cone 10: Obstruction 11: Measurement value of ultrasonic sensor 12: Measurement value of ultrasonic sensor 13: Measurement value of ultrasonic sensor

Claims (6)

[Claims] 1. An obstacle detection device mounted on a vehicle running on a road surface, wherein a plurality of sensors for detecting a distance to the road surface are arranged at an outer edge of a vehicle body of the vehicle. Detection device. 2. The obstacle detecting device according to claim 1, wherein the outer edge is a bumper of the vehicle. 3. The obstacle detecting device according to claim 1, wherein the sensor is an ultrasonic sensor. 4. An unmanned vehicle that travels on a road surface according to a preset program, wherein a plurality of sensors for detecting a distance to the road surface are arranged at an outer edge of a body of the unmanned vehicle. Unmanned traveling vehicle. 5. The unmanned traveling vehicle according to claim 4, wherein the outer edge portion is a bumper of the unmanned traveling vehicle. 6. The unmanned vehicle according to claim 4, wherein the sensor is an ultrasonic sensor.