JPH0481209B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is used for transportation equipment such as logistics systems and factory automation, and is used for transport equipment such as logistics systems and factory automation. The present invention relates to a collision prevention method for unmanned trolleys that allows unmanned trolleys to pass through an intersection without colliding with each other.

[Prior Art] Conventionally, due to the layout of the system, a plurality of unmanned carts are run to transport cargo to the destination.

An unmanned trolley refers to a trolley that has a power source on it and is able to run automatically.Currently, devices that enable unmanned running are used in peripheral equipment of automated warehouses, goods transport equipment on production lines, and automated trolleys. It is widely used in transportation equipment in processing lines, etc., and its feature is that it does not have dedicated rails. The fact that it does not have dedicated rails is advantageous in that it can run on general factory corridors, allowing it to use space shared with forklifts and people, and making it easy to change its running route.

However, since a plurality of unmanned trolleys travel in a horizontal and vertical direction, there is a risk that the unmanned trolleys will collide with each other at a merging point or an intersection. Therefore, collision prevention is essential, and traffic management of unmanned trolleys has traditionally been carried out.

Conventional control methods for preventing collisions with unmanned trolleys include closed section control, tracking control,
There are methods such as traffic control.

The closed section control method divides the layout into several sections on the control surface, allows one unmanned trolley to run within one section, and the following vehicle receives a signal from the standby signal zone at the entrance of the section. This will cause the machine to standby and stop.

However, in this control method, two
Both routes become one blocked section, so even if the following vehicle and the preceding vehicle are going on different routes, the following vehicle is forced to wait at the entrance of the section while the preceding vehicle is in the blocked section. There is.

In the tracking control method, each unmanned vehicle is tracked and managed by a ground station from its starting point to its destination point. In addition, the traffic control method uses serial signal transmission by guided radio as the interaction method for interactive control between the ground station side and the unmanned vehicle, and the layout is divided into several sections.
There is no need for a passage detector, a dialogue zone is set up at the entrance of the section, and the ground station needs to know where the dialogue zone is, so several dialogue zones are grouped into one group and dialogue is performed in groups. Zone scanning is performed, and when an unmanned vehicle enters the dialogue zone and sends information such as the machine number or destination to the ground station, a trough is created based on this information to improve collision avoidance and operational efficiency. This is to enable the device to be controlled.

However, both the above-mentioned tracking control method and traffic control method involve equipping a ground station with a control device and communicating with a ground-side computer to prevent multiple bogies from colliding at merging points or intersections. , and has the following drawbacks.

A computer-based control device installed on the ground side usually requires a minicomputer class and is expensive.

Every time the layout changes, software must be created each time, which increases the cost of the software.

The device is complicated because it communicates between the ground station and the trolley.

Since communication with the ground station is required, the communication device becomes complicated, and since the number of channels of the communication device is limited, the number of channels cannot be increased, and simultaneous communication may cause interference.

[Problems to be Solved by the Invention] In order to eliminate the drawbacks of the conventional technology, the present invention eliminates the need to give commands to the bogie side from the side that intersects with the ground station to prevent collisions of unmanned bogies. However, the aim is to avoid collisions by communicating between the bogies without installing a computer on the ground side.

[Means for Solving the Problems] In the collision prevention method for an unmanned trolley according to the present invention, a microcomputer sends a command to a travel drive control device to drive a travel drive motor based on a stored travel route, thereby causing a vehicle to move. In addition to allowing the bogie to run on its own, a track sensor detects the code board installed on the running surface and sends information on merging points and intersections to a microcomputer, so that when the bogie approaches a merging point or intersection, A microcomputer sends a command to an alarm receiver that detects infrared rays, which is attached to the front end of the bogie facing forward, diagonally to the right, diagonally to the left, and facing upward, to receive infrared warnings from other bogies, When the alarm receiver receives an infrared alarm, the bogies are stopped while the alarm is being received, waiting for the bogies to approach the merging point or intersection, and the alarm receiver If no infrared warning is received from another truck, or if there are no more infrared warnings from other trucks, the reception of the warning will be stopped, and a microcomputer installed at the front and rear ends of the truck will transmit an alarm. Send commands to the aircraft to send infrared warnings forward, diagonally to the right, diagonally to the left, backwards, diagonally to the right, diagonally to the left, and downward, respectively, and with the infrared warnings emitted, reach the merging point with the bogie. , an intersection, and stop issuing a warning after passing the merging point and intersection, thereby avoiding collisions between the unmanned trolleys.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show an outline of an unmanned trolley used to carry out the method of the present invention, and the unmanned trolley is designed to travel along a magnetic guidance zone 1 extending in the direction in which it is intended to travel. An example is shown below.

The unmanned trolley used in the method of the present invention is equipped with left and right traveling drive wheels 3 in the center of the trolley 2 so as to be driven by independent traveling drive motors 4, and left and right driven wheels 5 at the front and rear. Also, trolley 2
Magnetic detection sensors 6, 6' are attached to both front and rear ends of the trolley 2 as sensors for guiding the running of the trolley 2,
In a configuration in which the magnetic detection sensors 6 and 6' detect the magnetism of the guide belt 1 to automatically travel along the guide belt 1, the trolley 2 is provided with:
A microcomputer 7 is incorporated as a control device, and the traveling route formed by the guide strip 1 is divided into addresses, and these addresses are stored in the microcomputer 7, so that it can be used to determine where the trolley 2 is traveling and which address it will merge into. It should be possible to immediately know whether there are points or intersections. Furthermore, as shown in FIG. 1, the bogie 2 has metal code plates 8 installed on the ground along the guide strip 1 at four locations so as to form a substantially square shape when viewed from above. A track sensor 9 is attached to detect the code plate 8 and identify information on merging points and intersection points, and furthermore, an alarm transmitter 10 and an alarm receiver 11 are attached to the front and rear ends of the bogie 2. The alarm transmitter 10 is connected to another unmanned trolley at a merging point,
This is to send a warning (infrared transmission) that the vehicle is passing through an intersection and make the other unmanned vehicle wait for it to enter the merging point or intersection. , Attach the three in the straight direction, in the front left and right direction, and in order to prevent the alarm from reaching far, there is a risk of stopping the trolley at other merging points or intersections if the alarm reaches far, so install it in a slightly downward direction. and attach it. The alarm receiver 11 is
This is to check whether or not there is a bogie passing through a merging point or intersection by receiving an alarm from a bogie passing through a merging point or intersection. , and is attached to the lower side of the alarm transmitter 10 in a slightly upward direction in correspondence with the alarm transmitter 10. Furthermore, a traveling drive control device 12 (see FIG. 3) is installed on the bogie 2 to issue a rotation control command for the traveling drive motor 4, and as shown in FIG. ,
The alarm transmitter 10, the alarm receiver 11, and the travel drive control device 12 are each connected to the microcomputer 7, and as long as the magnetic detection sensor 6 detects the magnetism of the guide band 1, the commands from the travel drive control device 12 are activated. When the traveling drive motor 4 is driven and the trolley 2 is made to travel, and the alarm receiver 11 receives an alarm, it is input to the microcomputer 7 and a command to stop the traveling drive is sent to the traveling drive control device 12 from the microcomputer 7. The control device 12 is given an excitation command to the alarm transmitter 10 or a gate open command to the alarm receiver 11 from the microcomputer 7 based on the signal from the track sensor 9 so that the running of the trolley 2 is stopped. Based on the route address stored in the microcomputer 7, at a merging point or intersection point, an alarm is selected and issued in the direction in which the other truck approaching the merging point or intersection is coming. A command is issued to energize the alarm transmitter or open the gate of the alarm receiver that is oriented in that direction.

Regarding the above-mentioned driving guidance system for the unmanned trolley, several applications including Japanese Patent Application No. 78012/1983 (Japanese Unexamined Patent Publication No. 59/202512) have been filed.

With the above configuration, the magnetic detection sensor 6 detects the magnetism of the guide strip 1 along the traveling route stored in the microcomputer 7 built into the bogie 2 until the bogie 2 approaches the merging point or intersection. The trolley 2 travels unmanned by driving the travel drive motor 4.

Now, when the bogie 2 comes close to a merging point or an intersection point, a track sensor 9 detects a code board 8 installed on the ground. The code plates 8 are arbitrarily installed as shown in FIG. 4 in correspondence with the installation intervals of the track sensors 9 on the truck 2. For example, as shown in FIG. .
When route sensors A and B detect d, it is assumed that the vehicle has reached a confluence or intersection.
Further, when the code plates e and f are detected by the track sensors C and D, the end of the confluence or intersection point is notified, so that various information can be obtained by the combination of the four track sensors. .
Therefore, the track sensors A and B are connected to the code plates c,
When information indicating that the bogie 2 has reached the merging point or intersection point is obtained by detecting d, a command to open the gate is given from the microcomputer 7 to the alarm receiver 11 based on the signal from the track sensor. If no alarm is received from other trolleys, alarm transmitter 1
0 and passes through a confluence or intersection while issuing an alarm. These controls are performed for each bogie 2 that reaches a confluence or intersection from another route, so
When the bogie 2 arrives first at the confluence or intersection, the alarm transmitter 10 facing in a predetermined direction is excited by a command from the microcomputer 7 based on the signal from the track sensor, and the bogie 2 approaches the confluence or intersection while issuing an alarm. pass through. During this time, another bogie 2 approaching the above-mentioned confluence or intersection from another route detects the code plates c and d on the ground side by the track sensors A and B, and the gate of the alarm receiver 11 is detected. When the command to open is given by the microcomputer 7 built into the other truck 2, the alarm issued from the truck 2 that arrived first at the merging point or intersection is received by the alarm receiver 11, and the microcomputer 7 gives a stop command to the travel drive control device 12, and the travel drive control device 12 controls the rotation of the travel drive motor 4 to stop the other bogie 2 and wait for it to enter the merging point or intersection. Do it like this.

When the bogie that arrived first at the merging point or crossing point finishes passing through the merging point or crossing point, track sensors C and D are activated.
When the microcomputer 7 detects the code plates e and f and obtains information that the trolley 2 has passed through the merging point and the intersection point, the microcomputer 7 gives a command to the alarm transmitter 10 to stop issuing the alarm. When the alarm transmission is thereby stopped, the alarm receiver 11 of the other bogie 2 will no longer receive the alarm, and the signal from the alarm receiver 11 will cause the microcomputer 7 to issue an activation command to the traveling drive control device 12. Then, the other truck 2 passes through the merging point and the crossing point. During this time, the alarm transmitter 1 of the other truck 2
An alarm is being sent from 0.

When transmitting a warning while passing the above-mentioned merging point or intersection point, the warning transmitter 10 is installed slightly downward, so even if the interchange point is close, the warning from other than the target bogie may be received incorrectly. There is no fear that the truck will stop, and the truck can run smoothly. Further, the alarm transmitter 10, which issues an alarm while passing through a confluence point or an intersection point, is selectively activated based on the route information stored in the route table of the microcomputer 7 in which the travel route is stored, as described above. Therefore, there is no need to send or receive redundant signals. Also, the warning is
We decided to use infrared rays because it is desirable that the signal be sufficiently strong within the reachable range and that the signal does not leak outside the reachable range.

Note that the method of guiding the trolley 2 used to carry out the method of the present invention is a case in which the magnetism of the magnetic guide band 1 is detected by the magnetic detection sensor 6 and the trolley is run unmanned. In addition to the above, for example, there is a magnetic induction method in which a pair of detectors attached to the trolley detects the induced magnetic field generated by passing an electric current through an induction wire embedded in the floor of the running surface, and the trolley is caused to run. , an optical guidance method is adopted in which a light reflector is installed on the floor of the running surface, the light emitted from the cart is reflected by the light reflector, and the cart is guided by detecting the relative position of the reflected light and the cart. It goes without saying that, for example, a high-frequency waveform proximity switch may be used as the running path sensor 9.

[Effects of the Invention] As described above, according to the collision prevention method for unmanned trolleys of the present invention, a microcomputer is built into the trolleys, and collision avoidance is performed without going through ground equipment using a mutual alarm recognition system between the trolleys. It can produce excellent effects such as:

(i) Since there is no need for a ground-side control device (usually a minicon class) and there is no communication with the ground side, the equipment is simplified and the use of an expensive computer is eliminated to allow communication with the ground side. It is possible to reduce the total cost by using a simple communication device that is only used to issue work instructions without having to do so.

(ii) The equipment required for collision avoidance is simple, and the reliability is high because there are few devices operating at each merging intersection.

(iii) By using infrared rays as a warning and by devising the warning transmitter and the way in which the warning transmitter is installed, it is possible to accurately limit the range of the warning, such as the distance and direction, and also to ensure that the truck is at the merging point. The alarm is received and sent only when the crossing point is reached, which eliminates malfunctions and prevents unnecessary temporary stops of the carts and stalling due to mutual interference.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of an unmanned trolley for implementing the method of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a block diagram showing an example of an apparatus for implementing the method of the present invention. FIG. 4 is a plan view of the confluence or intersection point and its vicinity. 1 is a guide band, 2 is a trolley, 3 is a drive wheel, 4 is a traveling drive control device, 6 and 6' are magnetic detection sensors, 7
1 is a microcomputer, 8 is a code board, 9 is a track sensor, 10 is an alarm transmitter, and 11 is an alarm receiver.

Claims (1)

[Claims] 1 Based on the memorized travel route, the microcomputer sends a command to the travel drive control device to drive the travel drive motor to allow the bogie to travel on its own, and the code plate provided on the travel surface is detected by the travel path sensor. Detects and sends information on merging points and crossing points to a microcomputer, and the carts detect merging points and intersections.
When approaching an intersection, the microcomputer sends a command to the alarm receivers that detect infrared rays, which are installed at the front end of the truck, facing forward, diagonally to the right, diagonally to the left, and facing diagonally upwards, and sends a command to other alarm receivers. An infrared warning is received from the bogie, and if the alarm receiver receives the infrared alert, the bogie is stopped while the alarm is being received and waits for the bogie to approach the merging point or intersection. At the same time, if the alarm receiver does not receive an infrared alarm from another trolley, or if the infrared alarm from another trolley disappears, it will stop receiving the alarm and the microcomputer will A command is sent to the alarm transmitters attached to the front and rear ends of the trolley to transmit infrared alarms forward, diagonally to the right, diagonally to the left, backwards, diagonally to the right, diagonally to the left, and diagonally downward, respectively. A collision prevention method for an unmanned trolley, characterized by causing the bogie to pass through a merging point or an intersection with an alarm being issued, and stopping issuing the alarm after passing through the merging point or intersection.