JPH06266435A - Autonomous intersection control method for unmanned carrying car - Google Patents

Abstract

PURPOSE:To obviate generation of a queue by stopping in this side of a first area at the time when a signal wave of an execution frequency exists and continuing a detection until the signal wave is gone, executing transmission of a signal wave of a holding frequency, and transmitting the signal wave until an unmanned carrying car goes into the first area and passes through it at the time when the signal wave of the execution frequency does not exist. CONSTITUTION:In the case unmanned carrying cars A1, B1 advance simultaneously into the second area (b) from the third area (c) in two entrances A, B, when it is assumed that priority of the unmanned carrying car A1 from the entrance A is higher, and goes preferentially into the first area (a), the unmanned carrying car B1 existing in the second area (b) from the entrance B becomes on standby in this side of the first area (a), while executing transmission of a signal wave of a holding frequency (f1) and detection of a signal wave of an execution frequency f2. In this case, on the entrance A side, the next unmanned carrying car A2 can confirm a fact that the unmanned carrying car B1 exists in the second area (b) already from the detection of the signal wave of the holding frequency (f1), therefore, it becomes on standby in this side of the second area (b), even if its priority is higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autonomous control method at an intersection of an automated guided vehicle.

[0002]

2. Description of the Related Art In an automated guided vehicle system in which an automated guided vehicle travels along a guided line, the guided line branches, merges,
There are intersections. When a plurality of unmanned guided vehicles are run in such an unmanned guided vehicle system, intersection control is necessary to prevent collisions between the unmanned guided vehicles at points such as branching, merging, and intersections.

The ground control type and the autonomous control type are known as the intersection control, and the conventional autonomous control type intersection control related to the present invention is performed as follows. (1) A reflection-type or transmission-type photoelectric sensor or ultrasonic sensor is attached to an oblique front portion or a side portion of the vehicle body of each automated guided vehicle. In addition, the priority of passing through the intersection is determined. (2) When the own vehicle is approaching the intersection, the photoelectric sensor or the ultrasonic sensor detects whether or not another vehicle exists. (3) If no other vehicle is detected, the vehicle passes through the intersection. (4) When another vehicle is detected, if the other vehicle has a higher priority, the vehicle stops until the other vehicle passes the intersection. (5) If the own vehicle has a higher priority, pass the intersection.

[0004]

As described above, according to the conventional autonomous intersection control, collisions are avoided by the autonomous control of each automated guided vehicle, so that there is no need for special ground equipment and its control software. There is.

However, there is a problem in that the priority is set to the automatic guided vehicles that enter the intersection, so that a queue is generated and the efficiency of operation control is reduced. A specific example is as follows. (1) For simplicity, consider an intersection consisting of two entrances A and B and one exit C, and assume that one entrance A has a higher priority than the other entrance B. (2) Now, assuming that the automated guided vehicle A1 arrives at the entrance A and the automated guided vehicle B1 arrives at the entrance B at the same time, the automated guided vehicle A1 at the entrance A having the higher priority first enters the intersection,
The unmanned guided vehicle B1 at the entrance B having the lower priority will stop and wait at the entrance B until the unmanned guided vehicle A1 entering from the entrance A passes through the intersection. (3) At this time, while the automated guided vehicle A1 is passing through the intersection,
If the next unmanned guided vehicle A2 arrives at the entrance A with a high priority, after the preceding unmanned guided vehicle A1 has passed through the intersection, then the next unmanned guided vehicle A2 at the entrance A starts at the intersection. enter in. (4) Therefore, the automated guided vehicle B1 at the entrance B having the lower priority must wait at the entrance B again,
A queue is generated on the entrance B side.

It is an object of the present invention to provide an autonomous intersection control method capable of eliminating the occurrence of the above-mentioned priority-based queue.

[0007]

In order to achieve the above object, there are two or three autonomous intersection control methods for an automated guided vehicle according to the present invention.
In an autonomous intersection control method for an automated guided vehicle at an intersection having one or more entrances and one or two or more exits, in the vicinity of the intersection, a first area including the center of the intersection and a second area outside the first area are provided. When the automatic guided vehicle is divided into the area and the third area outside the second area and the automatic guided vehicle enters the third area, a signal wave having a predetermined first frequency (hereinafter, referred to as a standby frequency) exists. Detect whether or not
When there is a signal wave of the standby frequency, it stops before the second area and continues detection until there is no signal wave of the standby frequency. When there is no signal wave of the standby frequency, it enters the second area and stands by. A signal wave of the execution frequency is detected and whether or not a signal wave of a second frequency (hereinafter, referred to as an execution frequency) different from the standby frequency is present is detected. When it does, it stops before the first area and continues the detection until the signal wave of the execution frequency disappears, and it also transmits the signal wave of the standby frequency, and when there is no signal wave of the execution frequency, it moves to the first area. It is characterized in that a signal wave having a frequency for execution is transmitted until it passes through the first area.

[0008]

When the automatic guided vehicles A1 and B1 respectively proceed from the third area to the second area at the two entrances A and B at the same time, the operation is as follows. Since the two automated guided vehicles A1 and B1 transmit and detect the signal wave of the standby frequency, mutually confirm that there is an automated guided vehicle from another entrance in the second area. In this case, it is assumed that the automated guided vehicle A1 from the entrance A has a high priority, and this has priority to enter the first area. Then, the automated guided vehicle B1 in the second area from the entrance B waits in front of the first area while transmitting the signal wave of the standby frequency and detecting the signal wave of the execution frequency. At this time, even if the next unmanned guided vehicle A2 enters the third area at the entrance A side, this unmanned guided vehicle A2 indicates that the unmanned guided vehicle B1 is already in the second area by the signal of the waiting frequency. Since it can be confirmed from the detection of waves, even if the priority is high, it waits before the second area. Automated guided vehicle B1 from entrance B is entrance A
After the unmanned guided vehicle A1 from the
Enter the first area. Therefore, there is no queue due to the priority.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings along with its embodiments. FIG. 1 is a plan view showing an intersection state for explaining the principle of the present invention, FIG. 2 is a diagram showing a configuration example of an automated guided vehicle that realizes the present invention, and FIG. 3 is a diagram showing an example of a control procedure.

FIG. 1 shows an example of an intersection, which is composed of two entrances A and B and two exits C and D, where two traveling paths R1 and R2 intersect. The entrance markers MA and MB are located in front of the entrances A and B at the intersection, respectively.
Is installed. a, b, and c respectively show the 1st area, the 2nd area, and the 3rd area, the 1st area a is an area containing an intersection center, and the 2nd area b is outside the 1st area a and is near the entrance. The third area c is an area closer to the entrance, which is further outside than the second area b. Each area a, b and c is virtual,
Each automated guided vehicle A1, B1 measures the traveling distance from the place where the entrance-markers MA, MB are detected, and compares the measured value with the setting data of a predetermined area to determine which area,
Alternatively, it is determined by itself which position in the area.

FIG. 2 shows an example of the construction of unmanned guided vehicles A1 and B1. Each unmanned guided vehicle has a travel controller 1, a frequency generator 2, a transmitter 3, a receiver 4, and a frequency discriminator 5. And a marker detection sensor 6 and a travel distance detection sensor such as a rotary encoder 7.

The traveling control device 1 performs autonomous control-type intersection control according to the present invention in addition to traveling control such as starting, stopping, turning right, turning left and turning of an automatic guided vehicle which is normally performed. Therefore, when the entrance marker is detected by the sensor 6, it is determined in which area and in which area the vehicle is located from the measurement value of the travel distance obtained from the rotary encoder 7, and based on the determination result, an example is shown in FIG. Autonomous intersection control is performed according to the control procedure described above. The control procedure will be described below.

(1) When an automatic guided vehicle enters the third area c, the traveling control device 1 causes the receiver 4 and the frequency discriminator 5 to repeat reception of a signal wave of a standby frequency, for example, f1 one or more times. Receive command 8 is given. (Step S in FIG. 3
1, S2) (2) At this time, if a signal wave of the standby frequency f1 is received, another vehicle exists in the second area b, so after moving the vehicle ahead of the second area b, The vehicle stops, stands by here, and receives the signal wave of the waiting frequency f1 repeatedly. That is, the third area c is an area dedicated to receiving the signal wave of the standby frequency f1. (Steps S2, S3 of FIG.
S4) (3) If the signal wave of the standby frequency f1 is not received while the vehicle is traveling in the third area c or while waiting in the third area c, there is no other vehicle in the second area b. The control device 1 causes the host vehicle to enter the second area b, transmits the command signal 9 for transmitting the signal wave of the standby frequency f1 (continuous waveform) to the frequency generator 2 and the transmitter 3, the receiver 4, and the frequency discriminator 5. And the command 10 for receiving the signal wave having the execution frequency f2 (f2 ≠ f1) are alternately repeated. By repeating this transmission / reception, the other vehicle is notified that the own vehicle is present in the second area b, and the second area b is detected while detecting whether the other vehicle is present in the first area a.
To proceed. (Steps S5 and S6 in FIG. 3). (4) When the signal wave of the frequency f2 for execution is received, another vehicle exists in the first area a, so the vehicle advances to the front of the first area a and then stops and waits there. At the same time, transmission of the signal wave of the standby frequency f1 and the execution frequency f
The reception of the signal wave of 2 is repeated. That is, the second area b is a transmission / reception area. (Steps S6, S7, S in FIG. 3)
8) (5) If the signal wave of the frequency f2 for execution is not received while the vehicle is traveling in the second area b or while waiting, there is no other vehicle in the first area a, so the travel control device 1 determines The vehicle is made to enter the area 1a, and the transmission command 11 of the signal wave of the execution frequency f2 is repeatedly given to the frequency generator 2 and the transmitter 3. That is, while notifying other vehicles that the vehicle is present in the first area a,
To proceed. Therefore, the first area a is a transmission-only area. (Steps S9, S10, S11 in FIG. 3) (6) After passing through the first area a, the transmission of the signal wave of the execution frequency f2 is stopped.

By the above control, as shown in FIG.
Automated guided vehicles A1 and B at one entrance A and B, respectively
Considering the case where 1 travels from the third area c to the second area b at the same time, the two unmanned guided vehicles A1 and B1 transmit and detect the signal wave of the standby frequency f1. It can be confirmed that an automated guided vehicle from another entrance exists in the area b. In this case, if the automated guided vehicle A1 from the entrance A has a high priority and enters the first area a with priority, the automated guided vehicle B1 from the entrance B to the second area b will have the standby frequency. While waiting for the signal wave of f1 and detecting the signal wave of the frequency f2 for execution, it stands by in front of the first area a. At this time, even if the next unmanned guided vehicle A2 enters the third area c on the entrance A side, this unmanned guided vehicle A2 indicates that the unmanned guided vehicle B1 is already in the second area b by the waiting frequency. Since it can be confirmed from the detection of the signal wave of f1, even if the priority is high, it waits before the second area b. On the other hand, the automated guided vehicle B1 from the entrance B can enter the first area a after the automated guided vehicle A1 ahead of the entrance A passes through the first area a. Therefore,
Priority eliminates queuing.

The standby frequency f1 and the execution frequency f
Any of the two signal waves may be radio waves, ultrasonic waves, light, or the like. In the case of light, it may be considered as a frequency or a wavelength equivalent thereto.

[0016]

According to the present invention, in the autonomous intersection control of the system in which a plurality of unmanned guided vehicles travel, the problem of queuing caused by designation of the priority can be solved. Therefore, efficient operation control can be realized.

[Brief description of drawings]

FIG. 1 is a plan view showing an intersection state for explaining the principle of the present invention.

FIG. 2 is a configuration diagram of an automated guided vehicle according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a control procedure.

[Explanation of symbols]

 A, B entrance A1, A2, B1 automatic guided vehicle C, D exit MA, MB entrance marker a 1st area b 2nd area c 3rd area 1 travel control device 2 frequency generator 3 transmitter 4 receiver 5 frequency discrimination Instrument 6 Marker detection sensor 7 Travel distance detection rotary encoder 8, 10 Reception command 9, 11 Transmission command

Claims (1)

[Claims] 1. An autonomous intersection control method for an automated guided vehicle at an intersection having two to three or more entrances and one or two or more exits, the vicinity of the intersection being a first area including the center of the intersection, It is divided into a second area outside the first area and a third area outside the second area,
When the automatic guided vehicle enters the third area, it detects whether or not the signal wave of the predetermined first frequency exists, and when the signal wave of the first frequency exists, stops before the second area. Then, the detection is continued until the signal wave of the first frequency disappears, and when there is no signal wave of the first frequency, it enters the second area and transmits the signal wave of the first frequency, and Detects whether there is a signal wave of a different second frequency, and when there is a signal wave of a second frequency, it stops before the first area and the signal wave of the second frequency disappears. Detection is continued and the signal wave of the first frequency is transmitted. When there is no signal wave of the second frequency, it enters the first area, and the signal wave of the second frequency passes through the first area. A method for controlling an autonomous intersection of an automated guided vehicle, characterized by transmitting.