JPH0475404A - Controller for magnetic levitation carrier - Google Patents

Abstract

PURPOSE:To relieve impact to be applied on a movable body and an object to be carried by adding a signal fed from a signal generator to a reference position setting signal thereby producing a target position setting signal and then increasing or decreasing the target position setting signal gradually from a predetermined state. CONSTITUTION:A movable body 1, a switch group 30-1 for feeding and interrupting current supply to/from an electromagnet group 10-1 and the like are provided. When the switch 30-1 is switched due to movement of the movable body 1, target levitation value of the movable body 1 for a levitation device to be closed by the switch 30-1 is set larger than the levitation air gap value of the movable body 1 at that time point and then decreased gradually to a reference set value whereas the target levitation value of the movable body 1 for the levitation device opening the switch 30-1 is gradually increased from the reference set value to a value larger than the levitation air gap value of the movable body 1 at that time point based on a signal fed from a signal generator 60. Consequently, the movable body 1 can move stably along a rail 2 while keeping stable levitation without causing collision against an object to be carried or contact between the movable body 1 and a fixed magnetic pole 11-1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic levitation transport device that levitates and guides a movable body in a non-contact manner by controlling the magnetic attraction force of electromagnets disposed on the rail side. The present invention relates to a control device, and in particular to a control device for a magnetic levitation conveyance device that reduces the impact generated when selecting an electromagnet to function as the movable body moves, and makes it possible to smoothly move the movable body.

[Prior Art] An example of a conventional magnetic levitation conveyance device is shown in FIGS. 3 and 4.

In FIG. 3, electromagnetic coil 10-1.102.10-
Fixed magnetic pole 11-1.11-2.11 wound with 3...
-3... are arranged along the rail 2 that defines the moving direction of the movable body 1. Fixed magnetic pole 11-1.11-2.
11-3... Displacement sensor 12 that detects the distance (floating height) from the fixed magnetic pole to the movable body 1 is located near each of them.
-1.12-2.12-3... are arranged.

The output signals of the displacement sensors 12-1.12-2.12-3... and the reference position setting signals Vsl, Vs2, Vs3... for setting the floating position of the movable body 1 are denoted by reference numeral 22-1.2.
It is subtracted at the location indicated by 2-2.22-3...
The subtracted signal (deviation signal) is sent to the limiter 26-1.2.
6-2, 26-3... are input. Limiter 26-
1.26-2.26-3... are control devices 25-1.25-2.25-3... that output only the negative output of the deviation signal.
Output to each.

And control device 25-1.25-2.25-3...
... is the current amplifier 20-1.20-2.2〇-3...
The current amplifier is guided by the electromagnetic coil 10-1.
Supply current to 10-2, 10-3...

When the switches 30-1.30-2.30-3... are closed, the electromagnetic coils 10-1.10-2.103... correspond to (the negative output of) the deviation signal. Current flows. As a result, a magnetic attraction force acts on the movable body 1, and the movable body 1 receives the reference position setting signals Vsl, Vs2, Vs3.
It floats stably at a reference setting position corresponding to...

In the state in which the switches 30-1 and 30-2 are closed and the movable body 1 is floating by the fixed magnetic poles 11-1 and 11-2 (state 1 in Fig. 3), the linear motor 5 (Fig. 4) moves the movable body 1. When the body 1 is urged in the direction of the rail (rightward in FIG. 3), the movable body 1 moves to state 2 in FIG. In this state, the position of the movable body 1 in the moving direction is determined by the displacement sensor 12-3.
The output signal (detection signal) of the sensor is output to the moving position detection device 50. In response to this detection signal, the moving position detection device 50 closes the switch 30-3, causes the control magnetic attraction force of the electromagnetic coil 10-3 to act on the movable body 1, and maintains the stable floating of the movable body 1.

The movable body 1 continues to move further in the rail direction and reaches state 3 (third state).
), the moving position detection device 50 is activated by the switch 30.
-1 is opened to eliminate the control magnetic attraction force of the electromagnetic coil 10-1. Here, the timing to start the scanning performed in the above-mentioned state 3 is to start time measurement in the above-mentioned state 2, and output a signal when the time set by the timer 51 according to the moving speed of the movable body 1 has elapsed. To do this.

By repeating such scanning, the movable body 1 moves along the rail 2.
It moves along the line without contact.

[Problems to be Solved by the Invention] However, in the above-described conventional magnetic levitation conveyance device, when the switch 30-3 is closed in the above state 2, the movable body 1 is located below the reference setting position due to its own weight. As a result, the actual position of the movable body 1 no longer matches the reference setting position.

Therefore, the magnetic attraction force of the electromagnetic coil 10-3 suddenly acts on the movable body 1, and the tip of the movable body 1 in the moving direction (
There is a risk that the right end) may suddenly rise.

On the other hand, when opening the switch 30-1 in the above state 3, the magnetic attraction force of the electromagnetic coil 10-1 acting on the movable body 1 suddenly disappears, so that the rear end of the movable body 1 in the moving direction (left end) may drop suddenly.

In other words, in the conventional magnetic levitation conveyance device, the leading end in the moving direction is suddenly raised in state 2 in FIG. 3, and the rear end in the moving direction is suddenly lowered in state 3. There is a problem that an impact is applied to an object. Since the tip end of the movable body 1 in the moving direction is suddenly lifted, the fixed magnetic pole 11-1, 11-
2.11-3... There was a problem in that it came into contact with any of the following.

The present invention was proposed in view of the problems of the prior art described above, and includes controlling the magnetic attraction force so that the movable body gradually moves from the actual floating position to the reference setting floating position in state 2.3. An object of the present invention is to provide a control device for a magnetic levitation conveyance device that can reduce shocks applied to a movable body and a conveyed object on the movable body.

[Means for Solving the Problems] A control device for a magnetically levitated conveyance device of the present invention includes a movable body, a group of electromagnets fixed to the rail at equal intervals along a rail that defines the direction of movement of the movable body, and the electromagnet. a displacement detection means group for detecting a floating gap between each electromagnet of the group and the movable body;
A plurality of levitation devices including a group of switches that supply and cut off current to the group of electromagnets, and a group of control devices that perform control to stably levitate the movable body in response to the output of the displacement detecting means, a position determining means for determining the position of the movable body in the moving direction based on the output of the detection means; and a moving means for moving the movable body in the rail direction, when the movable body is moved in the rail direction by the moving means. Then, an electromagnet that should function to maintain stable levitation of the movable body is selected from the electromagnet group according to a command from the position determining means, and a switch corresponding to the selected electromagnet is opened or closed to levitate the movable body. In a magnetic levitation transport device that moves in the rail direction while moving the movable body, when the switch is opened or closed as the movable body moves, for a flotation device whose switch closes, the target levitation value of the movable body is set to the movable body at that time. For flotation devices that open a switch, the levitation target value of the movable body is gradually increased from the standard set value to the levitation gap value of the movable body at that point in time. A signal generator is provided to generate a signal that increases the magnitude of the signal.

[Function] In order to solve the above problems, the present invention adds the signal from the signal generator to the reference position setting signal to obtain a target position setting signal in a circuit for stably levitating a movable body, and when in the above state 2, The target position setting signal is set to a value larger than the detected value of the floating position of the movable body at that time, and thereafter is changed so as to gradually decrease to the reference position setting value. On the other hand, in state 3, the opposite is true, that is, the target position setting signal is used as the reference setting value, and thereafter it gradually increases and changes to a value larger than the detected floating position of the movable body at that time. .

By performing such control, in state 2, the target setting signal that sets the distance between the movable body and the fixed magnetic pole gradually changes, and the movable body gradually moves from the floating position at that point to the set reference position. to move upwards.

On the other hand, in state 3, the movable body gradually moves downward from the floating position at that time.

When the output operation of the signal generator is completed, the movable body enters a steady floating state in state 2. On the other hand, in state 3, the deviation signal becomes positive and no current flows through the electrode coil, so the switch can be opened without any problem.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 shows a part of an embodiment in which the present invention is applied to the conventional control device for the magnetic levitation conveyance device shown in FIGS. 3 and 4. FIG.

FIG. 1 shows members related to the fixed magnetic pole 11-1, and the output of the displacement sensor 12-1 is detected by the moving position detection device 55.
and is output to the limiter 26 via the subtracter 22-1.
-1 is input. This moving position detection deviceffi! 55 outputs commands to the signal generator 60 and timer 51. Then, the signal generator 6° outputs the signal Va, and the adder 23-
1, it is configured to be added to the reference position setting signal Vsl. Then, the sum of the signals Va and Vsl (Va + V
sl) is the displacement sensor 12-1 in the subtracter 22-1.
The difference from the output Vn of
1.

In FIG. 1, if the movable body 1 moves to the right in FIG. The device 155 receives the output signal of the displacement sensor 121, and determines the position of the movable body 1 in the moving direction (horizontal position in FIG. 1) based on the output signal. Then, a command to start outputting a signal as shown in FIG. 2A is issued to the signal generator 6o. At the same time, the moving position detection device 55 outputs an output to the switch 30-1 to close it, and also outputs a command to the timer 51 to start time measurement.

In the graphs shown in FIG. 2A, the vertical axis represents various signal values, and the horizontal axis represents time. Further, Vno shown on the vertical axis is the output signal value (detection signal value) of the displacement sensor 12-1 at the time when the moving position detecting device 55 gives a command to the signal generator 60 to start signal output. This corresponds to the dimension value of the air gap between the body 1 and the fixed magnetic pole 11-1. Further, Va on the vertical axis of FIGS. 2A and 2B indicates the output signal value of the signal generator 60, as described above.

Also the 2nd FI! In JA and B, V shown on the vertical axis
o is the signal value at the time when the signal generator 60 starts outputting the signal, that is, the initial value of the output signal value Va of the signal generator 60. In the case of control in state 2 (Fig. 2A), vO is set to a value appropriately larger than the value (Vno - Vsl) obtained by subtracting the setting standard value Vsl of the flying clearance from the output signal value VnO of the displacement sensor 12-1. is set.

In addition, in FIG. 2A, when the time Ts shown on the horizontal axis is reached, the signal output Va from the signal generator 60 becomes 0.

As is clear from FIG. 2A, the change from the start of generation of the signal output Va by the signal generator 60 (time O) to time Ts is exponential. Since the signal a force Va of the signal generator 60 changes by ζ as described above, the levitation target signal Vp (FIG. 2 C ) changes in the same way.

In FIG. 2C, until time tc, the displacement sensor output signal Vn is smaller than the levitation target signal Vp, so no current flows through the electromagnetic coil 10-1 due to the action of the limiter 26-1, and the movable body 1 is magnetized. The suction force does not work. After time tc has elapsed, a current flows through the electromagnetic coil 10-1, a control magnetic attraction force acts on the movable body 1, and the signal generator 60 outputs a signal V
According to the levitation target signal Vp, which is the sum of
-1) gradually decreases. Then, when the time Ts is reached, the floating gap of the movable body 1 becomes the set reference value Vsl.
This results in a steady floating state.

Furthermore, the movable body 1 moves rightward in FIG.
-1, the timer 51 gives a signal to the moving position detecting device 155, and the moving position detecting device 55 gives a command to the signal generator 60. Then, the signal generator 60 outputs a signal Va as shown in FIG. 2B. At this time, the output signal Va of the signal generator 60 shown in FIG. 2B and the flying target signal Vp shown in the second diagram have different characteristics from those in FIGS. 2A and 2C.

According to the control in state 3 in FIG. 1, the floating target signal Vp changes as shown in 211D, so initially the distance between the movable body 1 (rear end portion 1b) and the fixed magnetic pole 11-1 changes. Although the target value is a reference setting value, it is gradually increased to a value equal to or higher than the floating gap value of the movable body. Then, after time tc has elapsed, current no longer flows through the electromagnetic coil 10-1, and the moving position detecting device 55 detects the switch 3.
Open 0-1.

When the movable body 1 passes the magnetic pole 11-1, the control magnetic attraction force acting on the movable body 1 gradually changes by performing the operations or controls as described above. Therefore, stable floating of the movable body 1 is maintained without any impact being applied to the movable body 1, and the movable body 1 can stably move along the rail 2 without contact.

[Effects of the Invention] As explained above, according to the present invention, the movable body can maintain stable levitation without giving an impact to the movable body and the conveyed object on the movable body, and without causing contact between the movable body and the fixed magnetic pole. However, the excellent effect that the movable body can stably move along the rail can be obtained.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an example in which the present invention is applied to the conventional conveying device shown in FIGS. 3 and 4, and FIGS. 2A and 2B are characteristic diagrams showing examples of the output of a signal generator. Figures 2C and D are characteristic diagrams showing changes in the floating target signal caused by the signal generator, Figure 3.
4 are a circuit diagram and a front view showing an example of the system configuration of a conventional conveying device. 1... Movable body 2... Rail 2. 10-3... Electromagnetic coil 2.11-3... Fixed magnetic pole 12-3... Displacement sensor 26-3... Limiter 0-3. ...Switch device 51...Timer 10-1.10 11-1.11 12-1.12-2. 26-1.26-2. 30-1.30-2.3 50.55...Movement position detection 60...Signal generator 2@21st! !

Claims (1)

[Claims] a movable body, a group of electromagnets fixed to the rail at equal intervals along a rail defining the direction of movement thereof, and a group of displacement detection means for detecting a floating gap between each electromagnet of the electromagnet group and the movable body; , comprising a plurality of levitation devices including a switch group for supplying and cutting off current to the electromagnet group, and a control device group for controlling to stably levitate the movable body in response to the output of the displacement detection means, position determining means for determining the position of the movable body in the moving direction based on the output of the displacement detecting means;
a moving means for moving the movable body in the rail direction, when the movable body is moved in the rail direction by the moving means,
An electromagnet that should function to maintain stable levitation of the movable body is selected from the group of electromagnets according to a command from the position determining means, and a switch corresponding to the selected electromagnet is opened and closed to levitate the movable body. In a magnetic levitation conveyance device that moves in the rail direction, when the switch is opened or closed as the movable body moves, for a flotation device that closes the switch, the levitation target value of the movable body is set to the levitation gap value of the movable body at that time. From there, the target levitation value of the movable object is gradually decreased from the reference setting value to the reference setting value, and when the switch is opened, the levitation target value of the movable object is gradually increased from the reference setting value until it is equal to or greater than the levitation gap value of the movable object at that point. 1. A control device for a magnetic levitation conveyance device, comprising a signal generator that generates a signal that causes