JPH083754B2 - Security device for unmanned vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) [0001] The present invention relates to an improvement in a safety device for an unmanned vehicle that performs operations such as monitoring, cleaning, and transportation inside and outside a building.

(Prior Art) In recent years, as a means for monitoring the inside and outside of a building, cleaning, and carrying luggage without human intervention, a predetermined traveling path is driven by a traveling mechanism equipped with an electric motor. An unmanned vehicle that travels in the area has been used. This unmanned vehicle is designed so that there are no obstacles on the road, because obstacles on the road hinder the vehicle from traveling. However, it is necessary to equip a sensor for detecting obstacles on the traveling road in order to avoid the obstacles appearing on the traveling road of the unmanned traveling vehicle due to unexpected circumstances and the unmanned traveling vehicle colliding with the obstacle. is there. And, as a sensor for detecting such an obstacle, there are various ones such as an ultrasonic sensor, an optical sensor, and an infrared sensor, and among them, a wide range of application to an object, easy handling, Ultrasonic sensors have been most commonly used for reasons such as low cost.

FIG. 5 shows the relationship between the unmanned traveling vehicle and the obstacle detection by the ultrasonic sensor mounted on the unmanned traveling vehicle. Note that FIG. 5 shows a case where an unmanned vehicle is run on the floor of a building, for example.

In FIG. 5, 1 is an unmanned vehicle that travels on a road set on the floor, and 2a and 2b are provided at both ends in the vehicle width direction in front of the unmanned vehicle 1 in the traveling direction and emit ultrasonic waves. An ultrasonic sensor as an obstacle sensor that detects an obstacle on a traveling path by receiving a reflected wave from the obstacle, 3a and 3b are obstacle detection ranges of the ultrasonic sensors 2a and 2b, and 4 is an unmanned vehicle 1. The vehicle width 5 is a traveling road width necessary for the ultrasonic sensors 2a and 2b to travel without malfunctioning, and 6 is a fixed obstacle such as a convex portion of a side wall along the traveling road.

As described above, in FIG. 5, the ultrasonic sensors 2a and 2b provided in the unmanned vehicle 1 function to cause the ultrasonic sensor 2 to operate.
When an obstacle in the detection range 3a, 3b of a, 2b is detected, the traveling speed of the unmanned traveling vehicle 1 is decelerated or stopped in order to avoid collision with the obstacle.

However, the structure shown in FIG. 5 has the following problems. That is, when the unmanned traveling vehicle 1 travels along a place without a wall or along a uniform side wall, the obstacles on the traveling road are detected by the ultrasonic sensors 2a and 2b as described above,
The unmanned traveling vehicle 1 can be decelerated or stopped to avoid a collision with an obstacle. However, ultrasonic sensor 2
Since a and 2b have physical characteristics, the detection range varies depending on the material and shape of the object. For example, if there is a fixed obstacle (projection) 6 on the wall as shown in FIG. 5, the ultrasonic sensor 2
The sensitivities of a and 2b change, and the detection range widens as shown in 3a and 3b. As a result, when the unmanned traveling vehicle 1 is made to travel in a narrow area, the convex portion 6 of the side wall that does not hinder the traveling of the unmanned traveling vehicle 1 is erroneously detected as an obstacle.

Therefore, in order to prevent a malfunction as a safety device for the unmanned traveling vehicle 1 due to such a change in sensitivity of the ultrasonic sensors 2a, 2b, the traveling road width is set to be smaller than the vehicle width 4 of the unmanned traveling vehicle 1 as shown in FIG. It is taking big. But,
This method is not only wasteful because the traveling road width must be made larger than necessary, but the traveling area of the unmanned traveling vehicle 1 is also limited. On the other hand, the detection range of the ultrasonic sensors 2a, 2b is set in advance to prevent excessive reaction even if the sensitivity of the ultrasonic sensors 2a, 2b is increased by the convex portion 6 on the side wall. . However, this method lowers the sensitivity of the ultrasonic sensors 2a and 2b as a whole, and when the traveling speed of the unmanned traveling vehicle 1 becomes high, it is impossible to secure a sufficient stopping distance when necessary. It is also conceivable to temporarily lock the detection by the ultrasonic sensors 2a, 2b, but with this method, the original security function of the unmanned traveling vehicle 1 is deteriorated. Furthermore, in order to prevent erroneous detection of the ultrasonic sensors 2a, 2b,
A method of switching the detection sensitivity of the ultrasonic sensors 2a and 2b by providing a signal device for notifying a singular point of the traveling path may be considered, but this method requires an additional device and complicates the configuration of the entire system. In addition, the above problems,
The same occurs when an optical sensor, an infrared sensor or the like is used as an obstacle sensor.

(Problems to be Solved by the Invention) As described above, the conventional safety device for an unmanned vehicle not only detects an obstacle that hinders the traveling of the unmanned vehicle, but also detects an obstacle that does not hinder the traveling. However, there was a problem that it was overreacted and detected as an obstacle.

An object of the present invention is to provide an excessive number of obstacle sensors without securing the traveling road width unnecessarily large, without lowering the sensitivity, without lowering the original security function, and without complicating the structure. An object of the present invention is to provide a safety device for an unmanned traveling vehicle that can suppress reactions and can reliably detect only obstacles that do not interfere with traveling of the unmanned traveling vehicle without detecting any obstacle that does not interfere with traveling.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, in the present invention, a safety device for an unmanned vehicle that is driven by a traveling mechanism including an electric motor and travels on a predetermined traveling path. A laser sensor mounted on an unmanned traveling vehicle, which emits a laser beam and receives reflected light from an obstacle to measure the distance between the obstacle on the traveling path and the unmanned traveling vehicle; Using a repetitive movement mechanism that repeatedly moves the sensor in the vehicle width direction of the unmanned traveling vehicle and a traveling pulse obtained according to the rotation speed of the electric motor of the traveling mechanism, the traveling speed of the unmanned traveling vehicle is calculated from the number of traveling pulses. Running speed calculating means, a running pulse as an input, a running distance calculating means for calculating a running distance of an unmanned vehicle from the number of running pulses, distance measurement data from a laser sensor, and a laser section. Position data on the support of the vehicle, the running speed and running distance from the traveling speed calculating means and the travel distance computing means as an input,
Based on these, the measurement distance correction means for normalizing the distance measurement data to the obstacle ahead in the traveling direction at regular intervals, and the normalized distance measurement data at regular intervals from the measurement distance correction means are input, Based on the determination result by the measurement distance history determination means, the measurement distance history determination means for determining whether the obstacle is a static body or a moving body based on the distance measurement data of
To determine whether to stop or avoid the unmanned traveling vehicle, to avoid the unmanned traveling vehicle when the obstacle is a static body, and to stop the unmanned traveling vehicle when the obstacle is a moving body, The control device comprises a traveling pattern determining means for giving a safety control command for controlling the traveling speed and traveling direction of the unmanned traveling vehicle to the traveling mechanism.

(Operation) In the safety device for an unmanned traveling vehicle described above, as the unmanned traveling vehicle travels on the traveling path, the iterative movement mechanism repeatedly moves in the vehicle width direction of the unmanned traveling vehicle while the laser sensor is on the traveling path. The distance between the obstacle and the unmanned vehicle is measured. On the other hand, the traveling speed and traveling distance of the unmanned traveling vehicle are calculated by the traveling speed calculating means and the traveling distance calculating means in the control device from the number of traveling pulses obtained according to the rotation speed of the electric motor of the traveling mechanism. Then, on the basis of the distance measurement data from the laser sensor, the position data on the vehicle of the laser sensor, the traveling speed and the traveling distance from the traveling speed calculating means and the traveling distance calculating means, the measured distance correcting means at regular time intervals. The distance measurement data up to the obstacle ahead of the traveling direction is normalized. The normalized distance measurement data for each fixed time is input to the measured distance history determination means, and it is determined whether the obstacle is a static body or a moving body based on these distance measurement data. Then, based on the result of this determination, the traveling pattern determining means determines the traveling speed of the unmanned traveling vehicle,
A safety control command for controlling the traveling direction, that is, a safety control command to avoid the unmanned traveling vehicle when the obstacle is a static body and to stop the unmanned traveling vehicle when the obstacle is a moving body is issued. By being given to the traveling mechanism,
It is possible to detect and operate only obstacles that do not hinder the running of the unmanned vehicle.

(Embodiment) The present invention changes the travel operation plan of a traveling vehicle by measuring the distance to an obstacle by using a spot-measurable characteristic of a laser sensor and determining the traveling direction of a moving object. Is.

That is, the present invention mounts a laser sensor on a repetitive movement mechanism, measures the distance to an obstacle in the movement mechanism of the laser sensor by using the position and speed of a traveling vehicle, and measures the past By referring to the distance history to determine the traveling direction of the moving object and grasping the traveling direction of the moving object, the traveling vehicle is not only stopped when the moving object is present, but also The operation plan is changed so as to avoid contact.

Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings.

1 and 2 show an example of the configuration of a safety device for an unmanned traveling vehicle according to the present invention. FIG. 1 is a plan view showing a state in which sensors are mounted on an unmanned traveling vehicle, and FIG. It is a functional block diagram showing a control configuration example. The same element names as those in FIG. 5 are designated by the same reference numerals.

First, in FIG. 1, at a front side and a rear side of the traveling direction of the unmanned traveling vehicle 1, a repetitive movement mechanism capable of repetitively moving in the vehicle width direction of the unmanned traveling vehicle 1 (direction orthogonal to the traveling direction of the unmanned traveling vehicle 1). Equipped with 10a and 10b, and this repetitive movement mechanism 1
Laser sensors 11a and 11b are provided on 0a and 10b as distance measuring sensors that measure the distance between the obstacle on the road and the unmanned vehicle 1 by emitting laser light and receiving reflected light from the obstacle. It is installed. Here, the repetitive movement mechanism 10
The a and 10b are, for example, linear pulse motors.

On the other hand, in FIG. 2, the control device 20 outputs traveling pulses 12 obtained according to the rotation speed of a traveling motor, which will be described later, from a pulse encoder (not shown) attached to traveling wheels of the unmanned traveling vehicle 1 which is a part of the traveling mechanism. A pulse / traveling speed converting means as a traveling speed calculating means that receives the input and calculates the traveling speed of the unmanned traveling vehicle 1 from the traveling pulse number and outputs the traveling speed.
21 and a pulse / mileage conversion means 22 as a traveling speed calculation means for inputting the traveling pulse 12 and calculating and outputting the traveling distance of the unmanned traveling vehicle 1 from the traveling pulse number,
Distance measurement data A from the laser sensor 11a or 11b, position data B of the laser sensor 11a or 11b on the unmanned traveling vehicle 1, travel speed D from the pulse / travel speed conversion means 21 and pulse / travel distance conversion means 22 and travel Input the distance C,
Based on these, the measurement distance correction means 23 for normalizing the distance measurement data up to the obstacle ahead of the traveling direction of the unmanned vehicle 1 at regular time intervals, and the measurement distance correction means 23 normalize at regular time intervals. The measured distance data E as an input, and the measured distance history judging means 24 for judging the presence or absence of movement of the obstacle, that is, whether the obstacle is a static body or a moving body, based on the distance measurement data group E, Based on the judgment result G (distance to a static body or a moving body or an obstacle) by the measurement distance history judging means 24,
Security control commands K and L for controlling the traveling speed and traveling direction of the unmanned traveling vehicle 1 are determined by determining whether to make a temporary stop, avoidance action, or operator intervention.
Is composed of a traveling motor driver 25 and a steering motor driver 26, and a traveling motor 28, which is a traveling mechanism, and a traveling pattern determining means 25 for giving the steering motor 29.

Next, the operation of the safety device for an unmanned vehicle configured as described above will be described with reference to FIGS. 3 (a) to (d) and FIGS. 4 (a) and (b).

In FIG. 1 and FIG. 5, as the unmanned traveling vehicle 1 travels rightward in the drawing on the traveling path, the iterative movement mechanism 10a repeatedly moves the unmanned traveling vehicle 1 in the vehicle width direction while the laser sensor 11a is used. Obstacle 6 and unmanned vehicle 1 on the road
The distance to and is measured. On the other hand, from the number of traveling pulses 12 obtained according to the rotation speed from the pulse encoder attached to the traveling wheels of the unmanned traveling vehicle 1 which is a part of the traveling mechanism,
The pulse / traveling speed converting means 21 and the pulse / traveling distance converting means 22 in the control device 20 calculate the traveling speed D and the traveling distance C of the unmanned traveling vehicle 1.

Next, in the measurement distance correction means 23 of the control device 20, the distance measurement data A from the laser sensor 11a, the position data B of the laser sensor 11a on the unmanned vehicle 1, the pulse / travel speed conversion means 21.
Based on the traveling speed D and the traveling distance C from the pulse / traveling distance converting means 22, the distance measurement data to the obstacle 6 ahead of the traveling direction of the unmanned traveling vehicle 1 is normalized at regular intervals. In this case, the normalization of the distance measurement data up to the obstacle 6 is
For example, it is performed as shown in FIGS. 3 (a) to 3 (d). Note that FIG. 3 (a) shows a case where the unmanned vehicle 1 and the obstacle 6 approach each other, and the state in which the laser sensor 11a also repeats the repetitive motion is represented by P _I , P _II , and P _III. The vehicle speeds are shown as V _I , V _II , and V _III . Further, an example of the relationship between time / distance measurement data in this state is shown in FIG. 3 (b), and an example of the relationship between time / vehicle speed data at the same point is shown in FIG. 3 (c).

That is, the relational examples shown in FIGS. 3 (b) and 3 (c) are treated, for example, as the distance data at the position P _III of the laser sensor 11a at the positions P _I and P _II. Therefore, the following calculation is performed.

By performing the above calculation for each sampling time, the distance data of the front area of the unmanned vehicle 1 in the traveling direction can be obtained with reference to a certain position. FIG. 3 (d) shows this state. In this way, the measurement distance correction means 23 normalizes the distance measurement data from the laser sensor 11a at a fixed position.

Next, the normalized distance measurement data E for every fixed time is input to the measurement distance history determination means 24, and it is determined whether the obstacle is a static body or a moving body based on these distance measurement data. Be done. In this case, whether the obstacle is a static body or a moving body is determined as shown in FIGS. 4 (a) and 4 (b), for example. It should be noted that FIG. 4A shows that when the unmanned traveling vehicle 1 is approaching the obstacle 6, a moving obstacle such as a person newly occurs in the front area of the unmanned traveling vehicle 1 in the traveling direction. There is. At this time, the laser sensor 11 shown in FIG.
Assuming that the distance measurement data is normalized at the position a, FIG. 4B shows the three frames of the measured distance correction means 23. As shown in FIG. 4 (b), a moving obstacle such as a person can be recognized by the unevenness moving left and right on each frame. In addition, stationary obstacles can be considered as irregularities fixed on each frame. In this way, the measurement distance history determining means 24 determines whether the obstacle is a static body or a moving body based on the state of the unevenness.

Next, in the traveling pattern determination means 25, based on the determination result G in the measured distance history determination means 24, that is, whether the obstacle is a moving body or a static body, and in the case of a moving body, from the moving direction of the unevenness to the moving direction thereof. Accordingly, it is determined whether to make a temporary stop, avoidance operation, or intervention of an operator while grasping the reaction of the obstacle, thereby controlling the traveling speed and traveling direction of the unmanned vehicle 1. Security control command K, L
(Speed acceleration / deceleration command K, steering angle command L) is transmitted to the traveling motor 28, the traveling motor 28, and the steering motor driver 26.
By being applied to the steering motor 29, the unmanned traveling vehicle 1
It is possible to detect and operate only obstacles that hinder the running of the vehicle.

When the unmanned traveling vehicle 1 travels to the left in the figure on the traveling road, the laser sensor 11b repeatedly moves the unmanned traveling vehicle 1 in the vehicle width direction by the repetitive movement mechanism 10b, and the unmanned traveling vehicle 1 The distance from the traveling vehicle 1 is measured, and the security operation is performed by the same processing content.

As described above, in the safety device for an unmanned traveling vehicle according to the present embodiment, the laser sensors 11a and 11b, which are distance measuring sensors, are repeatedly moved in a direction orthogonal to the traveling direction of the unmanned traveling vehicle 1 and their respective positions are set. Unmanned vehicle 1
The relative distance between the unmanned traveling vehicle 1 and the obstacle is detected in consideration of the traveling speed of No. 1, and the temporary stop / avoidance operation / operator intervention is appropriately performed.

Therefore, since only the distance data of the unmanned traveling vehicle 1 in the vehicle width direction can be detected, it is only necessary to secure the traveling road width necessary for traveling of the vehicle, and the traveling area can be expanded. Further, since the moving body / static body of the obstacle can be determined by a simple laser sensor, the unmanned vehicle 1
It is possible to secure the optimum operation of. Thus,
The unmanned traveling vehicle 1 responds to obstacles that need to be avoided or stopped (impedes traveling), but does not respond to excessive reaction of the laser sensor that does not interfere with traveling of the unmanned traveling vehicle 1, A security device for an unmanned vehicle can be realized. In addition, it is not necessary to set the detection range of the sensor in advance to be narrow, or to provide a signal device for notifying a singular point of the traveling path, unlike the conventional case.
Excessive reaction of the sensor can be suppressed without reducing the sensitivity of the entire sensor and complicating the system configuration.

The present invention is not limited to the above-described embodiments, but can be implemented as follows.

In the above-mentioned embodiment, the case of the convex portion 6 of the side wall as shown in FIG. 5 is described as an example of the one which does not hinder the traveling of the unmanned vehicle 1, but the security device of the present invention is not limited to this. It is also effective for preventing an excessive reaction of the sensor due to some undesired cause such as noise or the like, and further preventing an excessive reaction of a momentary passing object which does not hinder the traveling of the unmanned vehicle 1.

Further, in the above-described embodiment, it is possible to increase the posture holding accuracy of the unmanned traveling vehicle 1 by installing a gyrolocator or the like in order to improve the moving object / static object judging accuracy of the measured distance history judging means 24. is there.

[Effects of the Invention] As described above, according to the present invention, it is possible to secure the traveling road width unnecessarily large, to reduce the sensitivity, and to prevent the original security function from being deteriorated. Safety of unmanned vehicles that suppresses overreaction of obstacle sensors without complicating and can reliably detect only obstacles that hinder driving without detecting objects that do not hinder the traveling of unmanned vehicles A device can be provided.

[Brief description of drawings]

1 and 2 are views showing an embodiment of a safety device for an unmanned traveling vehicle according to the present invention. FIG. 1 is a plan view showing a state of mounting a sensor on the unmanned traveling vehicle, and FIG. 2 is a safety device. 3 is a functional block diagram showing a control configuration example of FIG.
FIGS. 4 (a) and 4 (b) are diagrams for explaining the operation in the same embodiment, and FIG. 5 is a schematic diagram showing the relationship between the unmanned vehicle and the obstacle detection by the ultrasonic sensor. 1 ... Unmanned vehicle, 2a, 2b ... Ultrasonic sensor, 3a, 3b ...
… Detection range of ultrasonic sensor, 4 …… Vehicle width, 5 …… Required road width, 6 …… Fixed obstacle (side wall protrusion), 10a, 10b…
… Repetitive movement mechanism, 11a, 11b …… Laser sensor, 12 …… Traveling pulse, 20 …… Control device, 21 …… Pulse / traveling speed converting means, 22 …… Pulse / traveling distance converting means, 23 …… Measuring distance Compensation means, 24 ... Measured distance history determination means, 25 ... Travel pattern determination means, 26 ... Travel motor driver, 27 ...
… Steering motor driver, 28 …… Travel motor, 29 …… Steering motor.

Claims (1)

[Claims] 1. A safety device for an unmanned traveling vehicle, which is driven by a traveling mechanism equipped with an electric motor to travel along a predetermined traveling path, which is mounted on the unmanned traveling vehicle and emits a laser beam and reflects light from an obstacle. A laser sensor that measures the distance between the obstacle and the unmanned traveling vehicle on the traveling path by receiving the light; and a repetitive movement mechanism that repetitively moves the laser sensor in the vehicle width direction of the unmanned traveling vehicle, (A) to (e) of a control device, and a safety device for an unmanned vehicle. (A) A traveling speed calculation means that inputs a traveling pulse obtained according to the rotation speed of the electric motor of the traveling mechanism and calculates the traveling speed of the unmanned traveling vehicle from the number of the traveling pulses. (B) A travel distance calculation means that receives the travel pulse as an input and calculates the travel distance of the unmanned traveling vehicle from the number of travel pulses. (C) The distance measurement data from the laser sensor, the position data on the vehicle of the laser sensor, the traveling speed and the traveling distance from the traveling speed calculating means and the traveling distance calculating means are input, and based on these, at regular time intervals. Measured distance correction means for normalizing measured distance data up to an obstacle ahead in the traveling direction. (D) A measurement in which the normalized distance measurement data from the measurement distance correction unit at regular time intervals is input, and whether the obstacle is a static body or a moving body is determined based on the distance measurement data. Distance history determination means. (E) Based on the determination result of the measured distance history determination means, it is determined whether the unmanned traveling vehicle is stopped or avoided, and when the obstacle is a static body, the unmanned traveling vehicle is avoided. Driving pattern determining means for giving a safety control command for controlling the traveling speed and traveling direction of the unmanned traveling vehicle to the traveling mechanism in order to stop the unmanned traveling vehicle when the obstacle is a moving body.