JP2811422B2 - Automatic guided vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle provided with a collision prevention device.

[0002]

2. Description of the Related Art Automated guided vehicles (hereinafter abbreviated as "transported vehicles") are rapidly becoming popular due to recent trends in labor-saving. Even factories that initially introduced several vehicles tend to increase the number of transport vehicles in order to further rationalize. The transport vehicle has a track provided on the running surface (the track varies depending on the type of the steering mechanism of the transport vehicle. For example, there is a magnetism-generating band for magnetic detection and a metal band for light detection).
Proceed along. While the number of vehicles used is small,
Sufficient trajectory for each carrier can be secured.

[0003] Conventionally, what must be considered in a carrier is a collision with another carrier due to a speed difference between the carriers. As a collision prevention device attached to a conventional carrier, an ultrasonic sensor using reflection of ultrasonic waves and a sensor using electromagnetic induction are known.

FIG. 12 shows a configuration diagram of an ultrasonic sensor mounted on a conventional carrier. The ultrasonic sensor includes a combination of an ultrasonic transmitter 21, an ultrasonic detector 22, and an electronic circuit 23. The fan shape connected to the ultrasonic transmitter 21 indicates the transmission range 24, the fan shape connected to the ultrasonic detector 22 indicates the reception range 25, and the overlapping range 28 of the two fan shapes
Is the detectable range of the detection object.

[0005] The ultrasonic sensor detects the ultrasonic wave emitted from the ultrasonic wave transmitter 21 when the other carrier (detected object) approaches a certain distance and reflects the ultrasonic wave from the other unmanned carrier or the like. Then, the processing enters the electronic circuit 23 and outputs a stop signal 6 to a driving mechanism (not shown). The stop signal 6 can stop the carrier and prevent collision.

[0006] Such an ultrasonic sensor collision prevention device for a transport vehicle has been necessary and sufficient for the purpose of preventing a collision with a preceding vehicle.

As another prior art, a collision prevention device using electromagnetic induction is known. Compared with a collision prevention device using an ultrasonic sensor, a collision prevention device using electromagnetic induction has a feature that a reception range can be relatively widened. FIG. 15 shows a configuration diagram of a conventional collision prevention device using electromagnetic induction. This collision prevention device includes a transmission-only coil 1, a reception-only coil 2, and a transmission / reception circuit 3 that processes transmission / reception signals.

Further, the transmission / reception circuit 3 includes a transmission circuit 4 for driving the transmission coil 1 and a reception circuit 5 for processing a signal detected by the reception coil 2 and outputting a stop signal 6. Have. The receiving circuit 5 includes an amplification detection circuit 5a, a prohibition circuit 5b, and an output circuit 5c. The prohibition circuit 5b is provided for the purpose of preventing a malfunction caused by a transmission signal generated from the transmission coil 1 by itself. It functions so that the signal received by the dedicated coil 2 is invalidated and the stop signal 6 is not output.

FIGS. 16A and 16B show an example of mounting a collision prevention device using electromagnetic induction on a carrier. Figure 16 A is a plan view of a transport vehicle fitted with anti-collision device, FIG. 16
B is a front view of the carrier. In the figure, a rectangular shape shown by the four dashed lines in FIG. 16 A is a driving wheel, an arrow in FIG. 16 B shows the direction of travel. The receiving-only coil 2 is attached to the front side of the traveling direction of the carrier, the transmission-only coil 1 is attached to the rear side, and the transmitting / receiving circuit 3 is installed in the carrier.

[0010]

A problem with such a conventional carrier is a matter relating to a track for guiding the carrier. While the number of vehicles used was small, sufficient trajectories could be secured for each vehicle. But,
Due to restrictions on capital investment, high productivity in the same space has been desired. For this reason, a large number of transport vehicles are introduced, and the space given to the track of each transport vehicle is decreasing.

Therefore, merging, branching, intersection, and the like between a plurality of transport vehicles, which need not be considered in the past, occur. At the time of the newly generated merge, intersection, or the like, there is a possibility that a collision between the transport vehicles may occur.

The following points are disadvantages of the conventional ultrasonic sensor collision preventing device. First, there is a disadvantage that the detection distance cannot be extended. FIG. 13 shows a general use example of the ultrasonic sensor. As shown in the figure, two ultrasonic sensors on the left and right are mounted on the front side in the traveling direction of the carrier. Here, if the transmission output or the detection sensitivity is increased in order to extend the detection distance of the ultrasonic sensor, other obstacles such as building walls and pillars are inevitably detected, and the two carriers remain stopped. Stuck. As described above, when the detection sensitivity is increased, the operation is frequently stopped, and the efficiency of the conveyance automation is not improved.

Second, the conventional carrier has a drawback that it is difficult to prevent collision at a junction or at an intersection. FIG. 14 shows vehicles A and B for solving the problem at the time of merging. Transport vehicle A in FIG. 14, B in order to prevent a collision during merging, compared to the transport vehicle in FIG. 13, further add to the position of the angle ± 90 degrees two ultrasonic sensors with respect to the traveling direction I have. However, although it is possible to widen the detection range by the added ultrasonic sensor, to detect a counterpart transport vehicle at the same time by the timing of the confluence, both the transport vehicle, as shown in the right-hand portion of FIG. 14 will be stopped There is.

To summarize the problems of these ultrasonic sensors, if the detection distance is to be increased, a wall of the building is detected and stopped, and if the detection range (angle) is increased, the wall of the building is detected. Stopping, and stopping both carriers at the time of merging, and the like.

Next, referring to FIG. 17 and FIG. 18 , a collision preventing apparatus using electromagnetic induction which is another conventional example (FIG. 15 )
Will be described. The reception characteristic diagram of the collision prevention device of FIG. 15 is shown in FIG. 17. This reception characteristic diagram is a range where the reception coil 2 located at the center can detect a transmission coil (of another carrier) having a certain output. As is apparent from this directional pattern, the direction perpendicular to the receiving coil 2 (angle 90 degrees,
(270 degrees), a dead point with little sensitivity occurs.

At the dead point, the positional relationship between the coil for exclusive use of the carrier A and the coil for exclusive use of the carrier B becomes an angle of about 90 degrees, the sensitivity is almost lost, and the other party (another carrier) cannot be recognized. Similarly, if the positional relationship between the receiving coil B and the transmitting coil A becomes an angle of 270 degrees, the other party cannot be recognized. As described above, since the conventional collision prevention device has a dead point of directivity, there is a problem that a collision cannot be prevented when there is a partner vehicle entering from the dead point.

As described above, the conventional technique has the following problems. It is difficult for a collision prevention device using a conventional ultrasonic sensor to secure a wide directivity and a sufficiently safe detection distance required at the time of merging or intersection. Since the ultrasonic sensor has a limited directivity due to its structure, many devices are required to detect a wide range. When a plurality of devices are used, they are likely to malfunction due to interference with each other.

In order to extend the detection distance, since reflection is used, a wall or a pillar in a factory is detected, and unnecessary stoppage occurs. Furthermore, depending on the angle at the time of merging, there is a case where both carriers are stopped and do not move while detecting each other.

The conventional collision prevention device using electromagnetic induction has a dead point with almost no sensitivity in the reception characteristics, and therefore there is a possibility that the other carrier cannot be detected when the automatic guided vehicles cross each other. Therefore, it is difficult to reliably prevent collision at an intersection due to a dead point.

It is desirable that the directivity of the collision preventing device of the automatic guided vehicle is such that a safe distance can be ensured in consideration of the braking distance of the automatic guided vehicle without unnecessary stoppage. Furthermore, if the collision at the time of merging / crossing can be easily prevented, the degree of freedom of the track is increased and the limited space in the factory can be effectively used. Therefore, the above problem is solved, and a collision prevention device for an automatic guided vehicle that can easily realize collision prevention at the time of merging / crossing with only one device (stand-alone type) without providing a higher-level carrier vehicle group controller or the like. The realization of is desired.

Therefore, the present invention secures a safe distance between vehicles by using only one device,
An object of the present invention is to provide a carrier equipped with a collision prevention device in which both carriers do not stop.

It is a further object of the present invention to provide a carrier equipped with a collision prevention device capable of easily obtaining the required directivity with only one device.

[0023]

According to a first aspect of the present invention, in an automatic guided vehicle equipped with a collision prevention device, the collision prevention device processes two coils capable of transmission and reception and a signal from a reception coil. A receiving circuit that outputs a drive stop signal and a transmitting circuit that sends a transmitting signal to a transmitting coil, a coil switching circuit that alternately switches and connects the two coils to the receiving circuit and the transmitting circuit,
A timing circuit that outputs a timing signal to a receiving circuit, a transmitting circuit, and a coil switching circuit is provided, and two coils are installed separately from each other in the traveling direction of the carrier.

According to a second aspect of the present invention, there is provided the automatic guided vehicle according to the first aspect , wherein the transmission circuit further includes an output adjustment circuit, and the transmission circuit has two coils corresponding to the coil switching signal from the timing circuit. The transmission output is relatively increased when transmitting from the coil mounted on the rear side in the traveling direction of the transporting vehicle.

Furthermore the third invention, the first invention or second
In the automatic guided vehicle according to any one of the inventions,
Further, the transmission circuit has a transmission output reduction circuit that reduces the transmission output in response to the output of the reception circuit, and reduces the transmission output while the carrier is stopped.

Further, the fourth aspect of the present invention relates to the first to third aspects of the present invention.
In the automatic guided vehicle according to any one of the inventions,
Further, the timing circuit has a random number generator and a modulation circuit to randomly modulate the transmission and reception periods.

Furthermore a fifth aspect of the present invention, the first invention to fourth
In the automatic guided vehicle according to any one of the inventions,
Further, the receiving circuit has a prohibition circuit, and invalidates the receiving function during its own transmission in response to a signal from the timing circuit.

[0028]

According to the first aspect of the present invention, there is provided a transmitting circuit having two coils capable of transmitting and receiving, a receiving circuit for processing a signal from the receiving coil and outputting a drive stop signal, and a transmitting circuit for transmitting a transmitting signal to the transmitting coil. A receiving circuit, a coil switching circuit that alternately connects the two coils to the receiving circuit and the transmitting circuit, and a timing circuit that outputs a timing signal to the receiving circuit, the transmitting circuit, and the coil switching circuit. Coils move in the direction of travel
They are set apart from each other. By the coil switching circuit, two coils are connected to the receiving circuit and the transmitting circuit.
Both coils act as a transmitting coil and a receiving coil since they are alternately and continuously switched. In other words, it is equivalent to two transmission coils and two reception coils installed on the carrier at a distance from each other.

According to the second aspect of the present invention, the transmitting circuit has an output adjusting circuit, and transmits from the coil mounted on the rear side of the carrier of the two coils in response to the coil switching signal from the timing circuit. When the transmission output is relatively large.
Thus, between two carriers traveling on the same track in the same direction, the transmission power of the preceding carrier is always larger than that of the preceding carrier (the transmission of the succeeding carrier reaches the preceding carrier). The vehicle arrives first at the receiving coil of the vehicle, the subsequent transport vehicle temporarily stops, and the preceding transport vehicle priority traveling can be performed.

According to the third aspect of the present invention, the transmission circuit has a transmission output reduction circuit that reduces the transmission output in response to the output of the reception circuit, and reduces the transmission output while the carrier is stopped. Thus,
Due to the reduced transmission output, the succeeding carrier indicates its own presence and the transmission signal does not reach the receiving coil of the other carrier (priority carrier) with respect to the other carrier converging or intersecting. In this way, interference with the priority transport vehicle is prevented.

In the fourth aspect of the present invention, the timing circuit has a random number generator and a modulation circuit, and randomly modulates the transmission and reception periods. For this reason, a plurality of transport vehicles travel,
Even if the transmission is synchronized by chance, the transmission is out of synchronization at the next moment, and another carrier receives the previously transmitted signal of the carrier.

In the fifth aspect of the present invention, the receiving circuit has the inhibiting circuit, and disables the receiving function during its own transmission in response to the signal from the timing circuit. The timing circuit determines the transmission output period. In response to this timing signal, the prohibition circuit disables the reception function during its own transmission period, thereby receiving its own transmission and outputting a stop signal. Can be prevented.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a carrier according to a first embodiment of the present invention.

[0034] Example 1 is a collision prevention device of Example 1, a predetermined distance apart of for each transmission receivable two coils in the traveling direction of the automatic guided vehicle
Therefore , in principle, it is mounted horizontally on the floor.

FIG. 1 is an overall configuration diagram of a collision prevention device used in the carrier of the first embodiment.

A collision prevention apparatus according to the first embodiment shown in FIG .
Is a coil A (1), a coil B (2), a transmission / reception circuit 3
And a coil switching circuit 8 provided between the coils A and B (1, 2) and the transmission / reception circuit 3.

The coil A (1) and the coil B (2) may be exactly the same, and when selectively connected to the transmission circuit 4 via the coil switching circuit 8, function as a transmission coil. Functions as a receiving coil when selectively connected to the. For convenience, in the following description, coil A
(1) is installed on the rear side of the transport vehicle, and the coil B (2) is installed on the front side of the transport vehicle.

The transmission / reception circuit 3 includes a coil switching circuit 8
Drive coil A (1) or coil B (2)
Circuit 4 and a coil switching circuit 8
Signal detected by coil A (1) or coil B (2)
A receiving circuit 5 for processing the signal and outputting a stop signal 6
Having.

The receiving circuit 5 includes a coil A (1) or a coil A (1).
The transmission signal of another carrier sensed through the
An input amplification detection circuit 5a and a subsequent stage
The prohibition circuit 5b and the output signal from the prohibition circuit 5b are carried.
Output stop signal 6 to drive mechanism (not shown) for vehicle transport
Output circuit 5c. Among them, prohibition circuit 5
b indicates that it receives its own transmission signal and stops driving
This is provided to prevent malfunctions.
Function so as not to output a stop signal.

The transmission circuit 4 has an output reduction circuit 4a.
The output signal of the power circuit 5c (stop signal 6) is
It is also input to the road 4a. By this signal, the transmission circuit 4
From the transmission output to the coil switching circuit 8
Can do it.

Further, the collision preventing device shown in FIG.
For the transmission circuit 4, the reception circuit 5, and the coil switching circuit 8
It has a timing circuit 7 for sending a timing signal. Thailand
The mining circuit 7 includes a random number generator 7b and the random number generator 7b.
b of the transmission signal and the reception signal according to the random number output from
A modulation circuit 7a for modulating the period, and
Create an issue. The modulation circuit 7a transmits the modulated signal
Prohibition circuit 5b in path 4 and reception circuit 5 and coil switching
Output to the output circuit 8 respectively.

The signal is sent from the timing circuit 7 to the inhibition circuit 5b.
Signal to avoid detecting its own transmitted signal.
Therefore, during the transmission, the received signal is prohibited by the prohibition circuit 5.
b invalidates it.

The coil switching circuit 8 has two selectors, each having a movable contact a and fixed contacts b and c. A transmission signal from the transmission circuit 4 is input to the movable contact a1 of one selector. The movable contact a2 of the other selector is connected to the amplification detection circuit 5a of the reception circuit 5, and outputs the reception signal input from the coil. Movable contacts b1 and c2
Is connected to the coil B (2), and the movable contacts c1 and b2 are connected to the coil A (1). A switching signal is sent from the modulation circuit 7a of the timing circuit 7 to the coil switching circuit 8, and the movable contacts a1, a2 are changed to the fixed contacts b1, b
2 or c1 and c2, respectively.

A switching signal for causing the coils A and B to alternately act on the transmitting coil and the receiving coil by the coil switching circuit 8 is generated by the timing circuit 7. The switching signal is triggered , for example, by the rise of the transmission timing.
The signal is a signal that repeats high (H) and low (L) sequentially. For example, at the odd-numbered transmission timing , the switching signal becomes high (H), and the fixed contact a1 and the movable contact c1, the fixed contact a2 and the movable contact c2 are respectively connected, and the coil A (1) on the rear side in the traveling direction is The coil B (2) on the front side is connected to the transmission circuit 4 and acts as a reception coil at the same time. On the contrary,
At the even-numbered transmission timing , the switching signal becomes low (L), and the fixed contact a1 and the movable contact b1, the fixed contact a2 and the movable contact b2 are respectively connected, and the coil A on the rear side in the traveling direction is connected.
(1) is connected to the receiving circuit 5, and at the same time, the front coil B
(2) is connected to the transmission circuit 4.

As described above, the switching signal always causes the coil A and the coil B to function alternately as the transmission coil and the reception coil, and the transmission coil and the reception coil are each two (separated by the distance between the coil A and the coil B). It is equivalent to providing each.

The first embodiment has two modifications. First
As shown in FIG. 1 , in the modification of FIG. 1 , an output adjustment circuit 4b may be added to the transmission circuit 4 in addition to the output reduction circuit 4a that outputs the output to the coil switching circuit 8. The switching signal output from the timing circuit 7 to the coil switching circuit 8 is input to the output adjustment circuit 4b. When the switching signal is high (H) (that is, when the rear coil A (1) is a transmission coil), the output adjustment circuit 4a sets the transmission output to be slightly larger than the normal output and sets the switching signal to low ( In the case of L) (that is, when the front coil B (2) is a transmission coil), the output is adjusted so that the transmission output remains the normal output.

According to this modification, a specific example will be described later (FIG. 7 ).
As described in detail below, it is possible to avoid a problem that the two vehicles A and B traveling in the same direction on the same track receive each other and stop the problem that both vehicles stop, and the preceding transportation is performed. Car priority traveling can be executed. Therefore, the difference between the transmission output of the front coil and the transmission output of the rear coil is
The distance is determined in consideration of the distance between the coils A and B (that is, the length of the transport vehicle).

The carrier according to the first embodiment has the following features. (1) By the switching signal, the coils A and B alternately function as a transmission coil and a reception coil, which is equivalent to providing two transmission coils and two reception coils. Figure
2 and 3 show reception characteristics of the carrier according to the first embodiment. FIG. 2 shows the reception characteristics when the coils A and B (1, 2) are mounted horizontally with respect to the floor (the traveling surface of the carrier).
The two coils A and B are mounted so as to be shifted by a distance of “detection radius”. The reason for shifting the detection radius is that the effect of compensating for the dead point (FIG. 17 ) of the reception characteristics described above is maximized.

That is, as apparent from FIG. 2 , the dead point of the coil A (1) indicated by the broken line is
Compensation can be made with the detection radius of (2). Similarly, the dead point of the coil B (2) indicated by the broken line is supplemented by the detection radius of the coil A (1). Since the dead points are mutually compensated by the detection radius, the directional characteristics are improved to the shape shown by the solid line. In this way, the least sensitive part of one coil can be supplemented by the most sensitive part of the other coil. The range covered by shifting the reception characteristic of FIG. 17 described in connection with the prior art by the detection radius is the reception characteristic.

FIG. 3 shows exceptionally the coils A and B (1, 2)
Shows the reception characteristics when is mounted perpendicular to the floor (the traveling surface of the transport vehicle). When the coils A and B are mounted vertically, a circular directivity (non-directivity) is obtained around the coils A and B. By mounting this with a detection radius shifted as shown in the figure, the directional characteristics are improved to the shape shown by the solid line. Such an embodiment may be used depending on the required specifications of the carrier.

Returning to FIG. 1 , the features of the first modification will be described. When there are two guided vehicles traveling in the same direction on the same track, if the transmission output of the preceding vehicle and the transmission output of the following vehicle are the same, both vehicles will detect the other party at the same time and stop. Occurs. However, the output adjustment circuit 4b is provided to slightly increase the transmission output of the rear coil A (1), so that the succeeding transport vehicle is inevitably connected to the front coil B (2).
Receives the transmission of the preceding carrier. As a result, the stop signal 6 is generated from the receiving circuit 5 when the vehicle corresponds to the succeeding carrier,
At the same time, the stop signal 6 activates the output reduction circuit 4a to reduce the output. On the other hand, if it corresponds to the preceding carrier, the transmission output of the front coil of the succeeding carrier is relatively low,
The transmission does not reach the rear coil B of the preceding transport vehicle and does not stop.

Next, the two transport vehicles A according to the first embodiment,
A specific operation when B joins and a specific operation for transmission and reception will be described. FIG. 4 shows that the transport vehicles A and B are two parallel vehicles.
This shows the operation when passing each other in the orbit of a book. here,
In the case of the conventional directional characteristics, both carriers are stopped upon detecting each other. However, with the improved directivity of the first embodiment (see FIG. 2 ) shown by the solid line, they can pass each other without interfering with each other.

FIGS. 5 and 6 show another mode of merging / crossing. The carrier B is stopped upon receiving the signal from the carrier A. Here, the carrier B is the coil B (2) of the carrier A
Is detected (because the transmitting coil B (2) of the transport vehicle A is in the reception range of the transport vehicle B), the transport vehicle B stops while the transport vehicle A is detected, and the transport is stopped. The transmission output from the coil of car B is reduced. Therefore, the transport vehicle A can pass through without being affected by the transport vehicle B.

FIG. 7 shows a case where the vehicles A and B travel on the same track in the same direction. As described in the first modified example, each of the transport vehicles A and B can be controlled by the output adjusting circuit 4b to actuate each of the coils A on the rear side in the traveling direction as desired.
The transmission output from (1) can be made slightly stronger than the transmission output on the front side (coil) in the traveling direction. In other words, it can be said that the reception range of the front coil of the transport vehicle B is expanded. Accordingly, as shown in FIG. 7, always subsequent transport vehicle B
Is received before the preceding carrier A. At this time, the transport vehicle B stops and the transmission output from the coil is reduced. Therefore, when the succeeding carrier B approaches the preceding carrier A in accordance with the principle of priority traveling of the preceding carrier, the succeeding carrier B stops without affecting the preceding carrier A.

FIG. 8 shows a state where the vehicles A and B have traveled on the same track in opposite directions. In the case of FIG. 8 , the operation does not occur normally but occurs when either the transport vehicle A or the vehicle B makes a wrong track. in this case,
Each of the transport vehicles A and B detects the other party and temporarily stops, and the transmission output of both the transport vehicles A and B is reduced. Then, the transmission further proceeds by an amount corresponding to the reduction of the transmission output, and both of them stop. In this case, it is necessary to manually remove one of the transport vehicles A and B from the track to recover the vehicle.

FIG . 9 shows the timing of the collision preventing device according to the first embodiment.
Show The feature of this and the transmission and reception timing is that the transmission coil
And the receiving coil are equivalently two.
You. (1) to (4) relate to carrier A, and (5) to (8)
Relates to the carrier B. (1) is the transmission output of coil 1
High (H) is output during normal transmission, and low (L) is carrier inspection.
This represents the reduced output when the vehicle goes out (when the carrier stops). (2) is carp
This is the transmission output of the file 2. High (H) is normal like (1)
Transmission output, low (L) indicates reduced output when other carrier is detected.
Represent. (3) shows a transmission cycle. Thick black line indicates transmission signal
Power period, the space between adjacent black lines is the receivable period
Represents the interval. A broken line indicates one cycle of transmission and reception. (4)
Is the reception cycle. Similarly, (5) shows the transmission output of coil 1.
Power. As in (1), high (H) indicates normal transmission output,
Low (L) indicates a reduced output when another carrier is detected. (6)
Is the transmission output of the coil 2. High (H) as in (1)
Indicates normal transmission output, and low (L) indicates reduction when other carrier is detected.
Indicates output. (7) is the transmission cycle, (8) is the reception cycle
is there. In FIG. 9, the carrier B is a receiving coil in the traveling direction.
Shows the operation when the other party is received.

[0057] Finally, a description will be given of a second modification of the first embodiment. I want to refer to Figure 1. A selection signal is input from the timing circuit 7 to the output reduction circuit 4a. At this time, when the output reduction circuit 4a receives the signal on the front side (coil B) in the traveling direction of the carrier (that is, when the switching signal is low (L)), the transmission output of the transmission coil (coil B) on the front side in the traveling direction is output. When the signal is received on the rear side in the traveling direction (coil A) (that is, when the switching signal is high (H)), the transmission output of the transmission coil (coil A) on the rear side in the traveling direction is not reduced. You can do it. According to this modification, at the time of the merging in FIG. 5 and the intersection in FIG. 6 , the carrier B receives on the front side in the traveling direction (coil B), while the carrier A receives on the rear side in the traveling direction (coil A). However, the transport vehicle B stops and reduces the output, while the transport vehicle A proceeds as it is and does not reduce the output.

According to the transport vehicle of the first embodiment and its modified example described above, the collision of the transport vehicles and the collision prevention at the time of intersection can be easily realized without the control of the host controller or the like. In addition, this collision prevention device includes (1) measures for stopping both carriers due to mutual interference in parallel tracks (2) measures for stopping both carriers due to mutual interference at the time of merging and intersection (3) ) Prevention of collision due to speed difference between preceding and following vehicles (4) Measures to stop preceding vehicle due to interference of subsequent vehicles (5) Prevention of collision when facing one track Since the idea for realizing is included, it is possible to safely prevent collision between carriers even on a complicated track.

Effects of the Embodiment As described above, the collision preventing device according to the first embodiment can solve the following problems. (1) Both AGVs stop due to mutual interference in parallel tracks. (2) Both AGVs stop due to mutual interference at merging and intersection. (3) Collisions between automatic guided vehicles at merging and intersection. (4) A collision due to a speed difference between the preceding automatic guided vehicle and the following automatic guided vehicle. (5) A problem that the preceding automatic guided vehicle stops due to the interference of the following automatic guided vehicle.

Therefore, it is possible to prevent the collision between the automatic guided vehicles safely and without unnecessary stoppage with only one of the present apparatuses (stand-alone type).

The embodiment according to the present invention has been described above. However, the technical scope of the present invention is not limited to the above embodiments. Although the embodiment has been described with respect to an automatic guided vehicle, the present invention can be applied to a guided vehicle provided with a collision prevention device regardless of whether it is manned or unmanned. Figure 10
As shown in the above, the concept according to the present invention can be applied to an ultrasonic sensor. Further, as shown in FIG. 11, it can also be applied to an infrared sensor. The present invention is specified by the description of the claims.

The carrier equipped with the collision prevention device according to the present invention is a single collision prevention device that secures a safe distance and that both vehicles stop at the junction or intersection. There is no.

Further, the carrier equipped with the collision preventing device according to the present invention can easily obtain the required directivity.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an entire configuration of a first embodiment according to the present invention.

FIG. 2 is a diagram showing directional characteristics (reception characteristics) when the coil of the collision prevention apparatus of the first embodiment shown in FIG. 1 is mounted horizontally.

FIG. 3 is a diagram showing directional characteristics (reception characteristics) when the coil of the collision prevention device of the first embodiment shown in FIG. 1 is mounted vertically.

FIG. 4 is a perspective view showing a state where the collision prevention device of the first embodiment shown in FIG.
It is a figure which shows a mode that two conveyance vehicles pass by a parallel path.

FIG. 5 is a perspective view showing a state where the collision prevention device of the first embodiment shown in FIG.
It is a figure which shows a mode that two conveyance vehicles join.

FIG. 6 shows a second embodiment of the present invention in which the collision prevention device of the first embodiment shown in FIG.
It is a figure showing signs that two vehicles intersect.

FIG. 7 is a diagram showing an operation in a case where another carrier equipped with a similar collision prevention device approaches one side of a carrier equipped with the collision prevention device of the first embodiment in FIG. It is.

FIG. 8 shows a second embodiment in which the collision prevention device of the first embodiment shown in FIG. 1 is mounted.
It is a figure which shows operation | movement at the time of one conveyance vehicle facing on one track.

FIG. 9 shows transmission and reception timings at the time of merging of the collision prevention apparatus of the first embodiment in FIG. 1;

FIG. 10 is a diagram showing an overall configuration of a collision prevention device using ultrasonic waves according to another embodiment of the present invention.

FIG. 11 is a diagram showing an overall configuration of a collision prevention device using infrared light according to another embodiment of the present invention.

FIG. 12 is a configuration diagram of a conventional ultrasonic sensor.

FIG. 13 is an example of use of the conventional ultrasonic sensor of FIG.

FIG. 14 is a view for explaining a problem at the time of merging of a carrier equipped with the conventional ultrasonic sensor of FIG. 12;

FIG. 15 is an overall configuration diagram of a collision prevention device using electromagnetic induction according to the related art.

FIG. 16 is a diagram showing a specific example in which the collision prevention device using electromagnetic induction of the related art of FIG. 15 is attached to a carrier.

17 shows directional characteristics (reception characteristics) of the collision prevention apparatus using electromagnetic induction of the related art of FIG.

FIG. 18 is a view for explaining a problem at an intersection of a carrier equipped with the conventional collision prevention device utilizing electromagnetic induction of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission (dedicated) coil 2 reception (dedicated) coil 3 transmission and reception circuit 4 transmission circuit 4 a output reduction circuit 4 b output adjustment circuit 5 reception circuit 5 a amplification detection circuit 5 b inhibition circuit 5 c output circuit 6 stop signal 7 timing circuit 7 a modulation circuit 7 b Random number generator 10,21 ultrasonic transmitter 11,22 ultrasonic detector 12 infrared generator 13 infrared detector 23 electronic circuit 24 transmission range 25 reception range 28 overlap range

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-83711 (JP, A) JP-A-63-298605 (JP, A) JP-A-4-31911 (JP, A) JP-A-2-31911 273809 (JP, A) JP-A-54-105677 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05D 1/02

Claims (5)

(57) [Claims] In an automatic guided vehicle equipped with a collision prevention device, the collision prevention device processes two signals that can be transmitted and received, and a signal that processes a signal from the reception coil and outputs a drive stop signal. A transmission / reception circuit having a transmission circuit for transmitting a transmission signal to a circuit and a transmission coil, a coil switching circuit for alternately switching and connecting the two coils to the reception circuit and the transmission circuit, the reception circuit, the transmission circuit, and An automatic guided vehicle, comprising: a timing circuit that outputs a timing signal to a coil switching circuit, wherein the two coils are installed separately from each other in a traveling direction of the transported vehicle. 2. The automatic guided vehicle according to claim 1, wherein said transmission circuit further includes an output adjustment circuit, and said transmission circuit includes an output adjustment circuit, and said transmission circuit includes a transfer circuit in said two coils corresponding to a coil switching signal from said timing circuit. An automatic guided vehicle characterized by relatively high transmission output when transmitting from a coil mounted on the rear side in the traveling direction of the vehicle. 3. The automatic guided vehicle according to claim 1, wherein said transmission circuit further includes a transmission output reduction circuit for reducing a transmission output in response to an output of a reception circuit. An automatic guided vehicle characterized by reducing transmission output while the vehicle is stopped. 4. The automatic guided vehicle according to claim 1, wherein said timing circuit further includes a random number generator and a modulation circuit, and randomly modulates transmission and reception periods. An automatic guided vehicle characterized by the following. 5. The automatic guided vehicle according to claim 1, wherein the receiving circuit further includes a prohibition circuit, and the receiving circuit receives the signal during its own transmission in response to a signal from the timing circuit. An automatic guided vehicle characterized by disabling functions.