JPH03145910A - Stop controller for magnetic levitation carrying truck - Google Patents

Abstract

PURPOSE:To eliminate waste time in stop operation by performing deceleration control in accordance with a speed at which a carrying truck enters into a station. CONSTITUTION:When a carrying truck 3 enters into a station, a frequency pattern setting means 8 operates a frequency at which an inverter 5 is driven, in accordance with a speed detected through an entering speed detecting means 7, thus performing deceleration control through a stator coil 2. Output frequency from the frequency pattern setting means 8 is determined such that the carrying truck 3 is decelerated to have a predetermined speed at a fixed point immediately in front of a target stop position. Upon elapse of a predetermined time after passing through the fixed point, the carrying truck 3 is braked and stopped.

Description

[Detailed description of the invention] 【overview】

Regarding a magnetically levitated transport vehicle stop control device that stops a transport vehicle traveling by a linear motor along a rail at a fixed position, it shortens the wasted time before stopping the transport vehicle and enables substantial high-speed transport, and For the purpose of increasing conveyance efficiency, a magnetic levitation type conveyance device in which a stator of a linear motor is disposed on a rail, and a running element of the linear motor is disposed on a conveyance cart that runs along the rail. Supplying the output of an inverter that outputs alternating current at a set frequency to the stator, and decelerating the transport vehicle to a set speed at which the brake can stop the transport vehicle at a fixed position within an allowable range. , a magnetically levitated conveyance vehicle stop control device that operates the brake to stop the conveyance vehicle when the conveyance platform type reaches a stop position; , and frequency pattern setting means for supplying a frequency pattern corresponding to the inrush speed to a frequency setting terminal of the inverter.

[Industrial application field]

TECHNICAL FIELD The present invention relates to a magnetically levitated transport vehicle stop control device that stops a transport vehicle traveling along a rail by a linear motor at a fixed position.

[Conventional technology]

In semiconductor factories, devices for transporting wafers, masks, etc. between manufacturing processes are required to be capable of high-speed transport without generating dust. Among various conveyance devices, magnetic levitation type conveyance devices using linear motors generate the least amount of dust.
Attention has been paid. This magnetic levitation transport device has a stator of a linear motor on the rail, a running element on the transport vehicle, and an inverter changes the frequency of the current supplied to the stator to accelerate the transport vehicle. and deceleration control. Stop control of the transport vehicle at the station is performed as follows. That is, when the transport vehicle enters the station, the power supply line connected to the stator of the linear motor is switched, and the inverter supplies three-phase alternating current with a constant frequency to the stator as shown in Figure 8A. , generates a moving magnetic field in the opposite direction to this inrush direction, and when the speed of the transport vehicle reaches the set speed V as shown in FIG. 8B,
Turn off the inverter. This set speed V is the upper limit speed ■ at which the conveyance vehicle can be stopped at a fixed position within the permissible range using the brake. at a slightly lower speed. As a result, the magnetically levitated transport vehicle has a constant speed V,
Run with When the carrier vehicle reaches the stop position, the brake is activated to stop the carrier vehicle at this position. The time T for the transport vehicle to travel the distance at a constant speed V is,
It becomes wasted time. For example, V, = O, O5m/s, L =
In the case of O, 1m, T=2s.

[Problem to be solved by the invention]

However, the speed at which the transport vehicle enters the station is 8th.
If it is relatively small as shown in Figure C, for example, L=0.
．． 5 m, T = 10 seconds for the transport vehicle, and this dead time greatly reduces the average speed of the transport vehicle, making high-speed transport virtually impossible. Furthermore, the deviation of the conveyance time from the target value becomes large, and the conveyance efficiency deteriorates. In view of these problems, an object of the present invention is to provide a magnetically levitated carrier stop that can shorten the wasted time before stopping the carrier, enable substantial high-speed transportation, and increase the transportation efficiency. The purpose is to provide a control device.

[Means to solve the problem]

FIG. 1 shows the principle configuration of a magnetically levitated carrier stop control device according to the present invention. This magnetically levitated carrier stop control device is a magnetically levitated carrier in which a stator 2 of a linear motor is disposed on a rail 1, and a traveling element 4 of a linear motor is disposed on a carrier 3 that travels along the rail 1. It is for the device. The magnetically levitated transport vehicle stop control device detects the speed at which the transport vehicle 3 enters the station using the entry speed detection means 7, and sets a frequency pattern that is a function of time or position according to the entry speed. The output of the inverter 5 is supplied from the means 8 to the frequency setting terminal of the inverter 5, and the output of the inverter 5 is supplied to the stator 2 to decelerate the transport vehicle 3 to the set speed, and when the transport vehicle 3 reaches the stop position, the brake 6 is applied. It is configured to be activated to stop the transport vehicle 3. This set speed is a speed at which the conveyance vehicle 3 can be stopped at a fixed position within an allowable range by the brake 6. Also,
The entry speed detection means may be configured to directly detect the entry speed of the transport vehicle, or may be configured to detect the escape speed of the transport vehicle from the previous station and use this as the entry speed of the transport vehicle. Good too.

[Effect]

In the present invention, a frequency pattern corresponding to the speed at which the transport vehicle 3 enters the station is supplied to the frequency setting terminal of the inverter 5, and deceleration control is performed until the transport vehicle 3 reaches the set speed. Regardless of
It is possible to shorten the wasted time from when the vehicle reaches the set speed to the stop position. (Embodiment) An embodiment of the present invention will be described below based on the drawings. Fig. 3 shows the main part configuration of the magnetic levitation transport system. The transport vehicle IO moves between stations along the rail 12. In Fig. 3, only stations 8 and B are shown.The configuration of station 8 and the configuration of station B are the same, and the same numbers are given to the same components in the figure. B
ASB is added to each component related to the above. FIG. 2 shows details of the configuration for station B. On the rail 12 on the station B side, stators 14B, 116B and 18 of the linear motor are arranged along its longitudinal direction.
B is placed. A conductive flat plate 20 as a running element of the linear motor is arranged on the conveyor truck l in correspondence with the upper surface of the rail 12.
It is located at O. A slit plate 22 is provided on the side of the transport vehicle 10 and has rectangular wave-like irregularities formed along the traveling direction of the transport vehicle 1o. On the other hand, corresponding to this slit plate 22, on the station B side, photointerrupters 24B to 30B are arranged along the longitudinal direction of the rail 12 at the same intervals as the longitudinal width of the slit plate 22. These slit plates 22 and 7 photointerrupters 24B to 30B constitute a linear encoder, and photointerrupters 24B to 3
The position and speed of the transport vehicle 10 are detected based on the count value and pulse width of the 0B output pulse. Further, in the station B, an electromagnet 32B is provided corresponding to the stop position P2, and a yoke 34 is provided at the bottom of the carrier vehicle 10 in correspondence with the electromagnet 32B. With these electromagnets 32B and yoke 34B, the transport vehicle l
An electromagnetic brake is configured to stop O at stop position P2. Three-phase alternating current of frequency f is supplied to stators 14B-18B from inverter 36 via electromagnetic switch contacts 38B-40B, respectively. Contacts 38B to 40B are a set of contacts that switch and connect three-phase alternating current in order to switch the direction of magnetic field movement, and are shown in a simplified diagram in FIG. When stopping the transport vehicle 10, the stators 14B and 16B are used, and when starting the transport vehicle 10, the stators 16B and 18B are used. In addition, transport vehicle 1
0 passes through station B without stopping at station B, the stators 14B to 18B may be used to accelerate the transport vehicle IO. Electromagnet 32B1 Inverter 36B and contacts 38B to 40
The on/off of B is controlled by the controller 42B. When the inverter 36B is on, it outputs an alternating current voltage E with a frequency f set by the frequency pattern setter 44B as a voltage or current. This voltage E is proportional to the frequency f. In the frequency pattern setter 44B, patterns of frequency f with respect to elapsed time t are set for a plurality of carriage entry speeds V-+ (i=1 to N) in order to control the deceleration of the carriage. Figure 7A shows two frequency patterns. The pattern shown by a solid line is a case where the transport vehicle entry speed is relatively high, and the pattern shown by a - dotted chain line is a case where the transport vehicle entry speed is relatively small. When the frequency pattern setter 44B is supplied with the carriage entry speed v2 from the system controller 46, it determines that V21≦v2<v21,
A frequency pattern of V21 and V 2t 11 is searched, and a frequency pattern of the transport vehicle entry speed V2 is created from both patterns by interpolation. And the controller 42
In response to the pattern generation start signal supplied from B, this pattern is supplied to the setting terminal of inverter 36B. The carriage entry speed V is approximately equal to the velocity V at which the carriage 10 leaves station 8, and is detected by the controller 42A and supplied to the system controller 46. In addition, the frequency pattern setter 44B
Also, one pattern as shown in FIG. 5 for controlling the acceleration of the transport vehicle IO is set. Next, in the magnetic levitation transport system configured as described above, a control operation when starting the transport vehicle 10 at station A and stopping the transport vehicle 10 at station B will be described. (Δ) Acceleration control of the transport vehicle 10 by the controller 42A FIG. 4 shows the startup control procedure of the transport vehicle 10. (50) Upon receiving the activation signal from the system controller 46, the inverter 36A is turned on and an acceleration pattern generation start signal is supplied to the frequency pattern setter 44A. As a result, from the inverter 36A to the stators 16A and 18
An alternating current having a frequency as shown in FIG. 5A is supplied to A, the conductor flat plate 20 receives thrust from the stators 16A and 18A, and the carrier vehicle 10 is accelerated. The speed V of the transport vehicle IO changes as shown in FIG. (52) Detect the transport vehicle speed V, and ■ is the set escape speed V
Wait until it becomes 1. When V=V, (54) the inverter 36A is turned off. As a result, it escapes from station 8 at a speed of V and heads toward station B. This escape velocity vl is supplied to the system controller 46, and the system controller 46 supplies this as the entry velocity V to the frequency pattern setter 44B. The frequency pattern setter 44B creates a frequency setting pattern corresponding to this entry speed V2 using the interpolation method as described above. (B) Control of stopping the transport vehicle 10 by the controller 42B FIG. 6 shows a procedure for controlling the stop of the transport vehicle 10. (60) When the output pulses of the photointerrupter 24B are counted and it is detected that the leading end of the transport vehicle 10 has come to the stop control start position P1, (62) a deceleration pattern generation start signal is supplied to the frequency pattern setter 44B, At the same time, contacts 38B and 39B are turned on, and inverter 36B is turned on. As a result, a frequency pattern corresponding to the rush speed V is supplied from the frequency pattern setter 44B to the setting terminal of the inverter 36, and a three-phase alternating current of the set frequency is supplied to the stators 14B and 16.
Supplied to B. Then, the conductor flat plate 20 is transferred to the transport vehicle 10.
7B, the transport vehicle 10 is decelerated as shown in FIG. 7B. The solid line and the dashed-dotted line in FIG. 7B correspond to the solid line and the dashed-dotted line in FIG. 7A, respectively. (64) Detect the speed V of the transport vehicle 10 based on the signals from the photointerrupters 24B and 26B, and wait for this to reach the set speed VP. This setting speed ■2 is the electromagnet 3
2B is the upper limit speed ■ that allows the carriage 10 to be stopped at the stop position P2 within the allowable range. This value is slightly smaller than . When V=V, (66) Turn off contacts 38B and 39B and turn off inverter 3.
Turn off 6B. (68) Transport vehicle IO by photo interrupter 28B
Wait for the tip of the to be detected. That is, the transport vehicle 10
comes to the stop position P of station B. When this is detected, (70) the electromagnet 32B is turned on and attracts the yoke 34, thereby stopping the transport vehicle 10 at the stop position P2. FIG. 7C shows the change in position shown in FIG. 2 after the carriage enters station B. The solid line and the dashed-dotted line in FIG. 7C correspond to the solid line and the dashed-dotted line in FIG. 7A, respectively. In this way, after V=V, the dead time T until the transport vehicle 10 reaches the stop position P2 can be made as short as possible, and the transport vehicle 10 can be stopped at the stop position P2. Note that the present invention includes various other modifications. For example, in the above embodiment, a case has been described in which the frequency pattern is a function of time, but it goes without saying that this may also be a function of the position of the carrier. Furthermore, the speed V of the carriage entering station B may be detected on the station B side by the photointerrupter 24B or another photointerrupter placed in front of the photointerrupter 24B.

【Effect of the invention】

As explained above, in the magnetically levitated carrier stop control device according to the present invention, a frequency pattern corresponding to the speed at which the carrier enters the station is supplied to the frequency setting terminal of the circumferential inverter, so that the carrier reaches the set speed. Since the deceleration is controlled until the speed reaches the stop position, it is possible to shorten the wasted time of traveling to the stop position after reaching the set speed, regardless of the high or low entry speed. This has the excellent effect of increasing efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the principle structure of a magnetically levitated carrier stop control device according to the present invention. 2 to 7C relate to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a magnetically levitated carrier stop control device at station B, and FIG. 3 is a block diagram of the magnetically levitated carrier system. 4A to 5B are block diagrams showing the configuration of main parts; FIGS. 4A to 5B are related to startup control of the transport vehicle; FIG. 4 is a flowchart showing the startup control procedure; FIG. 5A is a diagram showing changes in the output frequency of the inverter; FIG. 5B The figure is a diagram showing the speed change of the transport vehicle, Nos. 6 to 7C.
The figures relate to the stop control of the transport vehicle, and Fig. 6 is a flowchart showing the stop control procedure, Fig. 7A is a line diagram showing the frequency pattern set in the frequency pattern setting device, and Fig. 7B is a diagram showing the frequency pattern set in the frequency pattern setting device. 7C is a diagram showing changes in the speed of the transport vehicle. FIG. 7C is a diagram showing changes in the position of the transport vehicle corresponding to FIG. 7B. Figures 8Δ to 8C relate to the stop control of the transport vehicle to explain the problems of the prior art, Figure 8A is a diagram showing the output frequency of the inverter, and Figure 8B is a diagram showing the output frequency of the inverter.
Figure 8C is a diagram showing the speed change of the transport vehicle when the speed at which the transport vehicle enters the station is relatively high. Figure 8C is a diagram showing the speed change of the transport vehicle when the speed at which the transport vehicle enters the station is relatively low. FIG. In the figure, 0 is the transport vehicle 2, rails 4A to 18A, 14B to 18B are the stator 0 is the conductor flat plate 4B to 28B as a running element, the photointerrupter 2B is the electromagnet 4, the yoke 6 is the inverter 38B to 40B, and the contact 42 is The controller 44 is a frequency pattern setter 46 is a system controller 6.Principle structure of the brake invention] Fig. Activation control procedure Fig. Start control of a magnetic levitation transport vehicle Fig. Stop control of a magnetic levitation transport vehicle Stop control of a magnetic levitation transport vehicle (conventional Technique) Figure 8A time Figure 8B time self 10/'+Ec71

Claims (1)

[Claims] A stator (2) of a linear motor is disposed on a rail (1), and a running element (4) of the linear motor is disposed on a carrier (3) that runs along the rail. The output of an inverter (5) that outputs alternating current at a set frequency is supplied to the stator of the magnetically levitated transport device, and the transport vehicle is brought to a fixed position within an allowable range using the brake (6). A magnetically levitated carrier stop control device that decelerates the carrier to a set speed at which it can be stopped, and when the carrier reaches a stop position, activates the brake to stop the carrier. an entry speed detection means (7) for detecting the speed at which the inverter (3) enters the station;
) A frequency pattern setting means (8) for supplying the signal to the frequency setting terminal of the magnetically levitated carrier.