JPH0549111A - Carrying control method - Google Patents

Abstract

PURPOSE:To prevent congestion of carriers by arranging position sensors for detecting passage of carrier at the inlet and outlet of each zone provided with a stator and arranging a speed sensor in front of the stator thereby detecting presence of the carrier in a downstream zone. CONSTITUTION:Position sensors arranged at the inlet and outlet of each zone provided with a stator detect entrance and departure of a carrier whereas a speed sensor arranged in front of the stator detects speed of the carrier. When a decision is made that the downstream zone is empty based on outputs from the position sensors and the speed sensor at decision step 24, stator in that zone is subjected to positive phase excitation 25 and advanced to the downstream. When the downstream zone is not empty, the speed of the carrier in that zone is detected 26 and if thus detected speed is not zero, stator in that zone is subjected to reverse phase excitation 27 and stopped. Control is then returned to step 24 where presence or absence of carrier in the downstream zone is decided again. According to the invention, congestion of carriers in each zone is eliminated resulting in enhancement of carrying efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport control method for operating a plurality of transport vehicles for transporting articles having small outer dimensions on the same guide rail.

[0002]

2. Description of the Related Art In recent years, office automation (O
A), as part of factory automation (FA), etc., slips, documents,
It is widely practiced to transport cash, materials, workpieces, parts and the like using a transport device. The transport device used for such transport is required to be able to transport the transported product quickly and quietly. For this reason, in this type of transfer device, a method of supporting a transfer vehicle on a guide rail in a non-contact manner is often adopted.

In order to support the carrier without contact, air or magnetism is generally used. Among them, the method of magnetically supporting the carrier is excellent in followability to the guide rail and noise reduction effect, and can be said to be the most promising supporting method.

By the way, in order to drive such a magnetically supported floating carrier, the secondary conductor plate of the linear motor is attached to the carrier and the stator of the motor is installed on the track side. However, the method of giving a thrust required for acceleration / deceleration to a carrier vehicle is most widely used because of its simple structure.

In this case, if the stator of the linear motor is continuously installed on the track side, the cost increases and the weight of the track itself also increases. Therefore, the stator is partially installed on the track.

When a plurality of guided vehicles are operated on the guide rail in which the stator is partially installed on the track as described above, it is carried out on a railway vehicle or the like in order to prevent collision and interference between the guided vehicles. As described above, it is necessary to perform control by dividing the zones along the guide rails. FIG. 4 shows an example of dividing control zones along the guide rails when operating a plurality of transport vehicles on the same guide rail as described above.

The stators 1a and 1b of the linear motor are installed at important points and points on the track, and the tips of one stator (when the stator and the secondary conductor mounted on the carrier are not overlapped Zones from the vicinity (where the thrust cannot be applied to the vehicle 2) to the tip of the stator arranged next are divided into one control zone.

The control device 3 is installed at an appropriate position on the track to detect a passage or presence of the transport vehicle 2 and a position sensor 4a.
~ 4f and the signals from the speed sensors 5a, 5b,
The linear motor drive devices 6a and 6b are controlled. The linear motor drive devices 6a and 6b receive a signal from the control device 3 and are supplied with power from a power supply device (not shown) to excite the corresponding stators 1a and 1b in positive phase or in reverse phase and not to the carrier vehicle 2. Contact is made to give thrust or thrust in the opposite direction to move forward or backward.

[0009] In this example, Zn, Z _n-1 are each one control zone, the zone Z transport vehicle 2, which is accelerated by the stator 1b to _n-1, the zones Z _n-1 from the zone Zn
Drive to. At this time, when passing the stator 1b, the carrier 2 does not receive thrust or reverse thrust until the next stator 1a, and the carrier 2 inertially travels.

That is, within a range in which the stator 1a or 1b can apply a thrust force or a reverse thrust force to the secondary conductor plate 7 mounted on the transport vehicle 2, the transport vehicle 2 performs controlled travel such as acceleration, deceleration, and stop.

If the zone ahead of the transporting vehicle 2 in the traveling direction is blocked, the control device 3 causes the position sensors 4a to 4f.
This is detected by the signal from. In this case, in order to prevent collision and interference between the carrier vehicles, the carrier vehicle 5 is moved to the zone Z
It is necessary to stop and wait within n-1. For that purpose, the control device 3 generates a reverse thrust force on the stator 1b when the carriage 2 reaches the stator 1b, and stops the carriage 2. On the contrary, assuming that the front zone is empty, thrust is generated in the stator 1b when the transport vehicle 2 reaches the stator 1b, and the transport vehicle 2 is accelerated. The flowchart of FIG. 5 shows an example of the operation of the above-described transport device, and functions as follows. The control device 3 includes a position sensor 4
By receiving the signals from a and 4c, it is checked whether or not the zone Zn ahead of the zone Z _{n-1 in} the traveling direction is empty. (Step 8) If the front zone Zn is empty, the zone Z _n-1
The stator 1b is positively excited and the carrier 2 is advanced to the front zone Zn. (Sweep 9)

On the other hand, the zone Z in the traveling direction of the zone Z _n-1
If n is blocked, the signal from the speed sensor is received,
The speed of the guided vehicle 2 entering on the stator 1b is detected.
(Step 10)

At this time, when the speed of the transport vehicle 2 is not zero, that is, when the transport vehicle 2 is entering the stator 1b, the stator 1b in the zone Z _n-1 is stopped until the transport vehicle 2 stops.
Reverse phase excitation. (Step 11)

When the transport vehicle 2 is stopped, the excitation of the stator 1b in the zone Z _n-1 is stopped. (Step 12) At this time, the carrier 2 is stopped on the stator 1b in the zone Z _n-1 and is in a standby state.

When it is confirmed that the zone Zn ahead of the traveling direction is empty (step 8), the standby state is released, and the zone Z _n-1
The stator 1b is subjected to positive phase excitation, and the carrier 2 is advanced to the front zone Zn. (Step 9)

In the transfer device having the above structure,
When a carrier tries to enter Zone Z _n-1 ,
The operation when the carrier is about to leave _n-1 will be described.

The above series of movements is shown in FIGS. 6 (a) to 6 (d).
Shown in. In FIG. 6A, the zone Z in front of the transport vehicle 2 is used.
Since n is blocked, the stator 1b is excited in anti-phase and the carriage 2 starts decelerating. In FIG. 6B, the front zone Z
Even if n becomes empty, the carrier 2 is still decelerating. In (c) of FIG. 6, the carrier 2 decelerates until it completely stops. In (d) of FIG. 6, the carrier 5 starts after it is completely stopped.

[0018]

As described above, in the conventional vehicle control device, when the zone ahead of the zone Z _{n-1 in} the traveling direction is blocked, the stator is used to stop the vehicle. Reverse-phase excitation, the carrier starts decelerating.While during this deceleration, if the zone in front of the vehicle in the traveling direction becomes empty, whether the zone in front of the vehicle in the traveling direction is empty until the vehicle completely stops. Since the check mark is not checked, the stator cannot be positively excited and the carrier cannot start. As described above, when a plurality of transport vehicles proceed continuously, the movement of the transport vehicles behind is wasted, causing unnecessary traffic congestion.

Therefore, an object of the present invention is to reliably prevent collision and interference between the carrier vehicles when operating a plurality of carrier vehicles on the guide rails where the stator is installed at key points on the track. Another object of the present invention is to provide a transportation control method that eliminates unnecessary traffic and smoothly moves.

[0020]

[Means and Actions for Solving the Problems] Guide rails divided into a plurality of zones, linear motor stators arranged in each zone of the guide rails, and a linear motor at a position facing the linear motor stators. With a mover attached, a transport vehicle that can run along the guide rails,
It has a sensor for detecting the passage of the guided vehicle provided on the entrance side and the exit side of each zone, the entrance side sensor of a certain zone detects the guided vehicle, and the exit side sensor detects the passage of this guided vehicle. During the detection, the vehicle presence determining means for determining whether a vehicle is present in the zone ahead of this zone in the traveling direction and the vehicle presence determining means are in front of the zone while determining that the vehicle is present. A drive command in the reverse direction is given to the linear motor stator in the zone to stop the transport vehicle, and if it is determined that there is no transport vehicle, the linear motor stator in the front zone is driven in the forward direction to drive the transport vehicle. Drive command means for giving a drive command.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

First, the structure of the carrier will be described.
2 and 3, the frame body 3 having a substantially inverted U shape is
The frame 3 is supported by a building or a supporting structure (not shown) along the transfer path, and at least the lower surface part is formed of a ferromagnetic material in the upper inside part of the frame 3, and a pair of guide rails 14 that are appropriately spaced apart are supported. It is supported by a tool. The transport vehicle 15 is magnetically supported by a magnetic support device 16 provided so as to face the guide rail 14, and is arranged so that it can travel. The secondary conductor plate 17 is provided on the upper portion of the transport vehicle 15 and faces the stator 18 of the linear motor, which is arranged downward at a predetermined interval in the central portion of the frame body 13 via a gap. The carrier 15 has a control device for controlling the magnetic support device 16.
A power supply device 20 for supplying electric power to the magnetic support device 16 and the magnetic support device 16 is mounted. In addition, a U-shaped emergency guide rail 21 is attached to the frame body 13.
Wheels 22a that engage with 21 in the vertical direction and wheels 22b that engage with 21 in the horizontal direction are provided in the transport vehicle 15. Further, the stator 18 is fixed to a top plate 23 lining it, and after inserting the stator 18 into an opening opened in the center of the frame body 13, the top plate 23 is fixed to the frame body 13. As a result, it is attached to the frame body 13. In the above configuration, when the secondary conductor plate 17 crosses the magnetic field by the stator 18, an eddy current is generated in the secondary conductor plate 17,
The Lorenker caused by the interaction between the eddy current and the magnetic field accelerates or decelerates the secondary conductor plate 17 and the carrier vehicle 15 to which the secondary conductor plate 17 is attached in a non-contact manner.

As shown in FIG. 4, the structure of the carrier device for operating a plurality of carrier vehicles on the same guide rail is the same as that of the conventional device, and the controller 3 controls the carrier 2 in each control zone.
The signals from the position sensors 4a to 4f and the speed sensors 5a and 5b for detecting the passage and the presence of are input to control the linear motor drive devices 6a and 6b. The linear motor driving devices 6a and 6b receive signals from the control device 3 and are supplied with power from a power supply device 20 (not shown), and the stators 1a and 1b.
Is subjected to normal phase excitation or reverse phase excitation to apply a thrust force or a reverse thrust force to the transport vehicle 2 in a non-contact manner. FIG. 1 is a flow chart showing the operational functions of the carrier device configured as described above. The operation of the present invention will be described below with reference to FIG.

In the decision step 24, the control device 3 receives the signals from the respective position sensors and checks whether the zone ahead of the zone Z _{n-1 in} the traveling direction, that is, the zone Zn is empty.

If the front zone Zn is empty, the process proceeds to the entry permission step 25, in which the stator 1b of the zone Z _n-1 is positively excited and the carrier vehicle 2 enters the front zone Zn. If the forward zone Zn is blocked by the forward traveling vehicle in determination step 24, the process proceeds to speed detection step 26, the signal from the speed sensor 5b is received, and the speed of the vehicle 2 entering the stator 1b is reached. To detect.

At this time, if the speed of the carrier 2 is not zero, that is, if the carrier 2 is entering the stator 1b, the operation proceeds to the stop operation step 27, and the stator 1b in the zone Z _n-1 is reversed. Phase excitation is performed, and the process proceeds to judgment step 24.

On the other hand, if the speed of the carrier 2 is zero in the speed detecting step 26, that is, if the carrier 2 is not on the stator 1b, or if the carrier 2 is stopped on the stator 1b. Then, the process proceeds to the stop operation end step 28, and the stator 7b in the zone Z _n-1 is not excited, and the process proceeds to the determination step 24.

Thus, this series of steps is repeated until the front zone is emptied. In the judgment step 24, when it is confirmed that the zone Zn in the forward direction is empty, the process proceeds to the entry permission step 25, the deceleration or stop state of the carrier 2 is released, and the stator 1b of the zone Z _n-1 is positive-phase excited. , The carrier 2 is moved to the front zone Zn.

With this structure, it is possible to prevent collision and interference between the carrier vehicles, and if the front zone becomes empty,
It is possible to move the transport vehicle smoothly without waiting for the transport vehicle to stop completely, and to eliminate unnecessary congestion.

In the above description, the carrier vehicle that is levitated by the magnetic support method has been described, but the applied support method may be air or other gas or liquid. Regarding the linear motor drive,
An AC zero-cross switch or other switch or frequency converter (inverter) can be used.

The control device can be realized by hardware such as a relay sequence or IC logic, or by software using a microcomputer or the like.

Further, in the present invention, the case where the linear induction motor is used for driving the levitation type conveying device is shown. Even when drive control is performed, it does not deviate from the gist of the present invention.

Further, although the present invention has been described with respect to the case of controlling the levitation transport vehicle, it can be applied to other similar transport devices, for example, a wheel drive type linear motor car.

[0034]

According to the present invention, the stator is installed on the orbital point,
When using multiple guided vehicles along distributed guide rails at important points, divide the guide rails into multiple zones, judge whether there is a guided vehicle in a certain section, and the guided vehicle exists. In this case, it is possible to prevent collision and interference between the carrier vehicles, and to move the carrier vehicles smoothly when the front zone becomes empty to eliminate unnecessary congestion. It is possible to provide a transportation control method with high transportation efficiency.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a control operation of a carrying device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a carrying device according to an embodiment of the present invention.

FIG. 3 is a front view showing the structure of a carrying device according to an embodiment of the present invention.

FIG. 4 is a system block diagram of a conventional carrier device.

FIG. 5 is a flowchart illustrating a control operation of a conventional transport device.

FIG. 6 is a diagram showing a congestion occurrence process of a carrier vehicle by a conventional carrier device.

[Explanation of symbols]

1a, 1b ... Stator, 2 ... Transport vehicle, 3 ... Control device, 4a, 4c, 4d, 4f ... Position sensor, 5a, 5
b ... Speed sensor, 6a, 6b ... Linear motor drive device, 7 ... Secondary conductor plate, 8 ... Judgment step,
9 ... Entry permission step, 10 ... Speed detection step,
11 ... Stop operation step, 12 ... Stop operation end step, 13 ... Frame body, 14 ... Guide rail,
15 ... Transport vehicle, 16 ... Magnetic support device, 17 ...
Secondary conductor plate, 18 ... Stator, 19 ... Control device,
20 ... Power supply device, 21 ... Emergency guide rails, 22a, 22b ... Wheels, 23 ... Top plate,
24 ... Judgment step, 25 ... Entry permission step,
26 ... Speed detection step, 27 ... Stop operation step,
28 ... Stop operation end step.

Claims (1)

[Claims] 1. A guide rail divided into a plurality of zones, a linear motor stator arranged in each zone of the guide rail, and a linear motor mover attached at a position facing the linear motor stator, It has a guided vehicle that can run along a guide rail, and sensors that detect the passage of the guided vehicles provided on the entrance side and the exit side of each zone, and the entrance side sensor of a certain zone detects the guided vehicle. While the exit sensor detects the passage of the guided vehicle, the guided vehicle presence determining means for determining whether the guided vehicle is present in the zone ahead of this zone in the traveling direction, and the guided vehicle presence determining means While it is determined that a vehicle exists, a backward drive command is given to the linear motor stator in the front zone to stop the transport vehicle, and if it is determined that no transport vehicle exists, Conveyance control method and a drive instruction means for giving a drive instruction in the forward direction for moving the transport vehicle to the linear motors stator.