JPS61202209A - Collision preventing device for unmanned truck at junction - Google Patents

Abstract

PURPOSE:To prevent completely the collision of unmanned trucks at the junction by providing a tool to be detected and a start signal projector at the front position of the junction at the ground side together with a start signal photodetector which receives the signal from the signal projector and a detector for tool to be detected set at the truck side respectively. CONSTITUTION:An unmanned truck 1 detects the guide lines 4(4a-4c) of drive paths 2(2a-2c) formed within a factory via a guide line sensor 3 and performs the steering guide by itself to keep its position on the drive path. Here a tool 28 to be detected and a ground side device 10 are set at the ground side together with a detector 29 and a photodetector 30 set at the truck side. The device 10 consists of a controller 13, a start signal projector 14, etc. When the truck 1 reaches an interference zone Z at the junction J, the detector 29 detects the tool 28 set on the floor surface to stop the truck 1. Then the truck 1 receives the signal light from the projector 14 through the photodetector 30 and starts again. The projecting interval of the projector 14 is set at the time when the collision is avoided between trucks. Thus the collision is avoided between unmanned trucks at the junction J.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an unmanned vehicle that is introduced in a factory or the like for the purpose of transporting articles.

Conventional technology When adopting a transportation system in which goods are transported by unmanned vehicles (hereinafter simply referred to as unmanned vehicles) in a factory, multiple unmanned vehicles are introduced on one traveling path, and In most cases, multiple unmanned vehicles are operating at the same time.In addition, there are many merging points on the driving route where multiple driving routes merge, and at these merging points, unmanned vehicles can interact with each other. There is a risk of collision.

Conventionally, methods for preventing collisions between unmanned vehicles at the above-mentioned merging points have been proposed, for example, in Japanese Patent Application Laid-Open No. 59-7252.
There is one described in Publication No. 4. The method described in the publication consists of: ■ Storing distance information from a reference point to a junction in advance; and ■ Based on travel distance information and speed information sent from an unmanned vehicle. Determine the time it takes for the unmanned vehicle to arrive at the merging point, ■ and perform the same calculations for other vehicles, and ■ compare the time it takes for the unmanned vehicles to reach the merging point found in steps (■) and () above. Then, it is designed to determine whether or not a deceleration command is output to the unmanned vehicle that arrives at the confluence point 5 later, and the extent of the deceleration command.

Problems to be Solved by the Invention The conventional system described above has the following problems.

1) If there are many merging points on the driving route,
The amount of information mentioned in (2) above that an unmanned vehicle must store increases and cannot be stored in the limited capacity of the storage device.

2) As is clear from the above (■■), a means of communication is required between the ground side and the unmanned vehicle, and this method is not applicable to unmanned vehicles that do not have such means of communication.

3) As the number of unmanned vehicles or the number of merging points increases,
The amount of calculations and comparisons increases, making it impossible to make quick decisions.

The present invention solves the above problems and provides a device that reliably prevents collisions between unmanned vehicles at a merging point.

Measures to solve the problem: On the ground side, a detection device and a signal light emitter gate are installed in front of the merging point. The device is equipped with a detector and a detector for detecting the above-mentioned detected tool.

Operation When the unmanned vehicle approaches the interference zone, the detector on the unmanned vehicle detects the detection target on the floor and stops. The stopped unmanned vehicle starts when the light receiver receives the signal light from the light projector on the ground. By setting the light emission interval of the above-mentioned floodlights to a time during which unmanned vehicles do not collide with each other, the following unmanned vehicle will receive the signal light after the unmanned vehicle that first received the signal light and started has passed the merging point. and take off.

Embodiment FIG. 1 shows two travel routes (2'a) and (2b) in a factory that has introduced a plurality of unmanned vehicles according to the present invention.
The confluence point (Jl) where the Jl.
The outline of the periphery of the interference zone TZ) is shown in a plan view. The unmanned vehicle (IA) (11) detects the guidelines' (4a) (4b) (4C) with the ff4)'94 sensor (3), and steers itself to prevent the position of the unmanned vehicle from deviating from the guidelines. It's running. In this example, the guidelines (4a), (4b), and
c) is a reflective tape, and the above guideline sensor (3)
Although an optical guidance method is adopted in which the sensor is an optical sensor that detects the presence or absence of the tape, it is of course possible to use other guidance methods. Although unmanned vehicles are classified as (IA) or (IB) depending on their driving position, their structures are all the same.

In addition, the travel routes (2a), (2b), and (2C) are based on the guidelines above.

This refers to the driving route of the unmanned vehicle formed by (4a), (4b), and (4c).

Next, details of the collision prevention device of this embodiment will be explained. This collision prevention system consists of a ground side device (10) installed on the ground side and an unmanned vehicle side device (2) installed on the unmanned vehicle.
0). .

First, the ground side device (10) will be explained based on FIGS. 8 and 9. This device (10) consists of a pulse oscillator (11), a light projector driver (12), a controller (13), and a starting signal projector (12).
4).

The details of each element are as follows: 1) The pulse oscillator (11) is, for example, a Muan pulse oscillator (11).

A constant multivibrator or the like is used, and the resistance value that determines the oscillation period is made variable by a volume control (15).

2) The light projector driver (12) is a transistor switch circuit having a capacity necessary to turn on and off a starting signal projector (14), which will be described later.

3) As the start signal projector (14), for example, a transmission type photoelectric switch projector is used. Note that by using a known photoelectric switch that modulates infrared light, it is possible to avoid interference from ambient light.

With the above-described device, a signal light is periodically projected from the start signal projector (14) (hereinafter simply referred to as a projector). The situation is shown in FIG. In this figure, level (1) indicates a state where the projector (14) is ON and a signal light is being projected, and level 0) indicates a state where the projector (14) is OFF and no signal light is projected. , the horizontal axis direction (16) indicates time. ON time (tl)
and OFF time (t2) are set to optimal values depending on the traveling speed of the unmanned vehicle, the state of the interference zone (Zl), etc. Setting of these values will be described later.

Next, the unmanned vehicle side device (20) will be explained based on FIGS. 6 and 7. FIG. 6 shows a schematic plan view of a three-wheeled unmanned vehicle (Il) as an example of an unmanned vehicle, and this unmanned vehicle is composed of the following elements: a traveling motor (21
), the drive wheel (23) is directly connected to the vertical axis (22) and steers around the vertical axis (22), the sprocket (24) is fixed to the vertical axis (22), and the chain (24) is attached to the sprocket (24).
25) A steering device (27) consisting of a steering motor (26) connected to the drive wheel (27) connected to the vertical shaft (22)
The guideline sensor (3) rotates in synchronization with the guideline sensor (3), which has a light source and light receiving element inside, and the metal plate (
28), for example, a starting signal receiver (30) using a known transmission type photoelectric switch receiver, a nozzle (31), and a driven wheel (32).
(32), a control device (34) having a built-in computer (33), which will be described later, etc., and an operation panel (35) protruding upward from the rear end of the unmanned vehicle, with an operation panel (35) fixed to its top surface. Section (36).

During normal driving, as shown in the block diagram in Figure 7,
The position of the guideline (4) on the floor (Fl) is detected by the guideline sensor (3), and the steering motor (26) is controlled via the computer (33) and motor controller (37).
is controlled to guide the unmanned vehicle (1) so that it does not deviate from the driving route.

When the unmanned vehicle (1) is stopped, the proximity switch (29) detects the metal plate (28), and the proximity switch (29) connects the computer (33) and motor controller (38).
The driving motor (21) is controlled via the unmanned vehicle (1).
to stop.

Further, (41), (42), (43), and (440) respectively indicate the RAM, CPU, ROM, and interface in the computer (33), and the driving state of the unmanned vehicle is set on the operation panel (36) of the operation unit (36). 35) can be changed.

When the starting signal receiver (30) receives the signal light (P),
The light reception signal is sent to the travel motor (21) via the computer (33) and motor controller (38), and the unmanned vehicle (1) starts traveling.

Next, the operation of this embodiment will be explained. As shown in Figure 1, when an unmanned vehicle (IA) (IB) traveling on any of the travel routes (2a) (2b) approaches an interference zone (Z), the proximity switch (29) switches the vehicle to the respective travel route. It detects the upper metal plates (28) (28) and stops once. Light is projected from the light projector (14) at regular intervals, and when the light receiver (30) of the stopped unmanned vehicle receives the light, the unmanned vehicle starts traveling again. Therefore, the stopping time of an unmanned vehicle is at most OFp time (t2) if there is only one driving route.
It is.

When the unmanned vehicles (IA) and (IB) on the two travel routes (7a) and (2b) pass through the interference zone (Z) at a constant interval, there is no risk of collision between the unmanned vehicles. Two unmanned vehicles (IA) (IB) enter the hour zone (Z) almost simultaneously.
□ Explain the behavior in a situation where a slight force ′) is coming towards ) and there is a risk of collision.

1) Two unmanned vehicles (IA) (IB) stop at their respective stopping positions almost simultaneously.

2) The unmanned vehicle (unmanned vehicle (IA) in the figure) that first received the signal light from the light projector (14) starts traveling.

3) If the ON time (tl) of the signal light is made shorter than the time it takes for the unmanned vehicle (IA) to start after receiving the signal light, the unmanned vehicle' (IB) will be in the shadow of the unmanned vehicle (IA). □゛One signal light will not cause two unmanned vehicles (IA) ('IB) to start. Therefore, the unmanned vehicle (IB) remains stationary. 14) The signal light OFF time (t2) is set to a time during which the two unmanned vehicles do not collide, depending on the speed of the unmanned vehicles (IA) (IB) and the distance from each stop position to the merging point.

Therefore, when the stopped unmanned vehicle (IB) receives the next signal light and starts, the preceding unmanned vehicle has passed the merging point (J), or even if it has not passed, the following unmanned vehicle The vehicle is traveling in a position where it will not collide with the vehicle (IB). - Figures 2 and 3 show layout changes of the embodiment shown in Figure 1. As shown in Figure 2,
Also when three or more driving routes merge, or a third
The present invention is also applicable to a case where non-parallel travel routes merge as shown in the figure. Since each device and operation are the same as in the above-described embodiment, detailed explanation will be omitted, and the same members will be given the same reference numerals.
□・・Furthermore, FIG. 4 shows an embodiment in which traveling routes (2a') and (2b) in mutually orthogonal directions merge. In this figure, (5o) indicates the reflector,
The signal light (P) from the projector <14) is transmitted to the reflector (50).
The light is reflected and can be received by the light receiver (30) of the unmanned vehicle (IB) stopped at the stopped position.

Furthermore, Fig. 5 shows an example of preventing a collision of an unmanned RT at a Jumonji intersection.
There are optical receivers (3 o
) (□30) are installed on each side, and a floodlight (1
4i) (14b) are also provided. When one of the floodlights is activated, the other is set to be inactive, and when hooked, it causes the unmanned vehicle (IB) to travel in the direction of arrow (51) and the unmanned vehicle (IA) to travel in the direction of arrow (52). When you want to give priority to driving, activate the floodlight (14b). Although not shown, when approaching a cross intersection, only one direction of signal light is allowed to pass. By providing reflective plates at the four corners and installing floodlights on the outside of each reflective plate, it is possible to handle merging in four directions.

Note that as the start signal, not only light but also ultrasonic waves, laser light, etc. can be used. In addition to the above-described embodiments, the detection object for stopping may be, for example, a guideline cut or thickened, and the unmanned vehicle may be stopped based on this information.

Effects of the Invention - As explained above, according to the present invention, it is possible to reliably prevent collisions between unmanned vehicles at merging points using a very simple device and without performing complicated calculations. did it.

[Brief explanation of drawings]

Figure 1 is a diagram showing one embodiment of the present invention, and is a plan view schematically showing the interference zone axis and unmanned vehicles in a factory that has introduced a plurality of unmanned vehicles, and Figure 2 is a plan view showing three traveling routes. Fig. 3 is a schematic plan view of an interference zone where two non-parallel running routes are merging, and Fig. 4 is a schematic plan view of an interference zone where two non-parallel running routes are merging. FIG. 5 is a schematic plan view of a merging interference zone, FIG. 5 is a schematic plan view of criss-crossing travel routes, FIG. 6 is a plan view showing the structure of a three-wheeled unmanned vehicle as an example of an unmanned vehicle, and FIG. The figure is a block diagram showing the control unit of the unmanned vehicle shown in Fig. 6, Fig. 8 is a block diagram showing the ground side device of the present invention, and Fig. 9 is a time chart showing the ON-OFF state of the floodlight. . (IA) (IB) ..., unmanned vehicle (2a) (2
b) (2c) ... Travel route (14) ... Start signal receiver (28) ... Detected N (29) ... Detector (30) ... Start signal receiver (J )... Merging point (Z)... Interference zone Φ Part 滌 滌□〜 * −

Claims (1)

[Claims] In a transportation system in which a plurality of unmanned vehicles are operated simultaneously on a travel route, detection devices are respectively provided on the ground side near the entrance of the travel route in an interference zone where the plurality of travel routes merge. , and a start signal projector is provided near the entrance, and each unmanned vehicle is provided with a start signal receiver that receives the signal light emitted from the start signal projector, and a detector that detects the detected device. A collision prevention device for unmanned vehicles at a merging point.