JPH0787646B2 - Displacement sensor correction method for magnetic levitation transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a levitation electromagnet for levitating a carrier by magnetic attraction, and a track facing the target plate to detect the distance to the target plate provided on the carrier. The present invention relates to a method for correcting a displacement sensor of a magnetic levitation transfer apparatus, in which a plurality of displacement sensors are provided along the track, a transfer table is levitated by a levitation electromagnet, and a linear motor moves along a track.

[0002]

2. Description of the Related Art In a conventional displacement sensor of a magnetic levitation transport apparatus, an output voltage varies due to an error in its mounting position and an error in manufacturing the displacement sensor itself. In order to solve this, in the past, adjustment was performed only manually by using an adjustment volume attached to the sensor amplifier.

[0003]

In the conventional adjusting method,
When the number of displacement sensors provided is large, adjustment takes a very long time, and there is a problem in the adjustment process.

It is an object of the present invention to provide a method for correcting a displacement sensor of a magnetic levitation transport device that facilitates adjustment of a performance difference due to the error of each displacement sensor.

[0005]

According to the present invention, a levitation electromagnet for levitation of a carrier table by a magnetic attraction force is provided, and a target plate for detecting a distance from a target plate provided on the carrier table is provided. In a method of correcting a displacement sensor of a magnetic levitation transfer device, a plurality of displacement sensors are provided facing each other along a track, and a transfer table is levitated by a levitation electromagnet and moved by a linear motor along the track. In order to ensure that the distance between the displacement sensor and the target plate is different, the carrier table with several structural differences is reciprocated a predetermined number of times along the track, and when the carrier table reciprocates, the output of each displacement sensor with respect to the target plate A computer for calculating the voltage and accumulating and calculating the calculated output voltage data corrects the performance difference between the displacement sensors.

[0006]

As described above, the performance difference of each displacement sensor, that is, the output characteristic for the type of carrier is stored in the computer, so that the output of each displacement sensor is corrected by the computer. In this way, it is easy to move the carriages with different distances between the displacement sensors and the target plate a predetermined number of times on the orbit, and obtain the output voltage of each displacement sensor at that time. The difference or position error can be corrected correctly. As described above, according to the present invention, it is not necessary to individually adjust the offset voltage and the gain through the volume of the displacement sensor amplifier, which conventionally requires a huge amount of time for work.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a magnetic levitation transfer apparatus for carrying out the present invention. In the figure, the magnetic levitation transfer apparatus is a track 1.
And a carrier 10. A transport rail 2 is erected at the center of the track 1, and a linear induction motor 3 is continuously provided at the top of the rail 2. Lifting electromagnets 4 ... And pulling electromagnets 5 ..., which are levitation electromagnets, are vertically opposed to each other at a predetermined interval on the lower left and right sides of the rail 2, respectively. On the upper left and right sides of each, guide electromagnets 6 ... Are arranged facing each other vertically at a predetermined interval. Then, the pulling down electromagnet 5
Are arranged in the vicinity of the vertical direction displacement sensors 7 ... At predetermined intervals, and in the vicinity of the guiding electromagnets 6 ... It is placed in advance.

On the other hand, on the lower left and right inner sides of the carrier 10,
A target plate 11 made of a magnetic material is horizontally projected, and is inserted between the lifting electromagnets 4 ... And the pulling down electromagnets 5 ... Further, a target plate 12 made of a magnetic material is vertically provided on the upper left and right inner sides of the carrier 10 so as to face the guiding electromagnets 6 ... Further, touchdown bearings 13 that come into contact with the upper surfaces of both sides of the track 1 are provided at lower portions on both outer sides of the carrier 10. Touchdown bearings 14 that come into contact with the inner surfaces of both sides of the track 1 are provided on the bottom surfaces of both sides of the carrier 10. It is provided. Then, the displacement sensors 7 ..., 8 ...
Are connected to a computer or computer 20 via A / D converters 21, respectively.

In FIG. 2, vertical touch-down bearings 13 having several outer diameters are prepared in order to determine the gap between the vertical displacement sensor 7 and the target plate 11. As the horizontal touchdown bearing 14, several kinds of outer diameters are prepared in order to determine the gap between the horizontal displacement sensor 8 and the target plate 12. Further, the present invention is not limited to this, and as shown in FIG. 3, the vertical displacement sensor 7 and the target plate 1 are inserted between the carrier 10 and the target plate 11.
1. Several kinds of adjusting plates 15 that make the gap with 1 variable are prepared, and are inserted between the carrier 10 and the target plate 12 to make the gap between the horizontal displacement sensor 8 and the target plate 12 variable. The adjusting plate 16 may be prepared.

Next, examples of the present invention will be described. Both touch down bearings 13, 14 or both adjusting plates 15,
16, both displacement sensors 7, 8 and both target plates 11,
Conveyor stand 1 with structural difference in gap value from 12
0 is automatically run along the rail 2 by a linear motor drive, and the output voltages of the displacement sensors 7, ..., 8 ... Arranged on the track 1 are accumulated and stored in the computer 20. The computer 20 accumulates data for the number of reciprocations of the carriage 10 which is set in advance by a program, and also the displacement sensors 7 ... 8 ... by traveling of the carriage 10 having another gap value. · Accumulate the output voltage of. Then, after performing the above process for all the designated carriages, all the displacement sensors 7, ..., 8 ... Are displayed based on the obtained relationship between the displacement sensor output voltage and the gap value. A reference straight line L as shown in 4 is derived. Therefore, the individual displacement sensors 7 ...
For 8 ..., so as to get on the reference value line L, the offset voltage (y intercept of the reference line L, that is, y0) and the gain (the slope of the reference line, that is, Δy / Δx)
The correction value of is calculated and used as the calibration data. By this series of procedures, what is regarded as a uniform output voltage that is not influenced by the output voltage of each displacement sensor 7, ... It can also contribute to running.

[0012]

Since the present invention is configured as described above, it is not necessary to manually adjust the offset voltage and the gain individually via the volume of the displacement sensor amplifier, which has been conventionally performed manually. It is possible to save an enormous amount of time required for the adjustment, and to make it possible to stably move the carriage without being influenced by variations in the output voltage of each displacement sensor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a magnetic levitation carrier device embodying the present invention at right angles to the carrier direction.

FIG. 2 is a sectional view illustrating a touchdown bearing.

FIG. 3 is a sectional view illustrating an adjustment plate.

FIG. 4 is a diagram illustrating an offset and a gain for obtaining a reference line according to the present invention.

[Explanation of symbols]

 L ... Reference straight line 1 ... Track 2 ... Rail 3 ... Linear induction motor 4 ... Lifting electromagnet 5 ... Pulling down electromagnet 6 ... Guide electromagnet 7 ... Vertical direction Displacement sensor 8 ... Horizontal displacement sensor 10 ... Transport table 11, 12 ... Target plate 13, 14 ... Touchdown bearing 15, 16 ... Adjustment plate 20 ... Computer 21 ... A / D converter

Claims (1)

[Claims] 1. A levitation electromagnet for levitation of a carrier table by a magnetic attraction force is provided, and a plurality of displacements are made along a trajectory facing the target plate in order to detect a distance to the target plate provided on the carrier table. In a method of correcting a displacement sensor of a magnetic levitation transfer device, in which a sensor is provided and a transfer table is levitated by a levitation electromagnet and moved by a linear motor along an orbit, a displacement sensor and a target plate are combined to configure the displacement sensor. A plurality of types of structurally different carrier distances are reciprocated along the track a predetermined number of times, the output voltage of each displacement sensor with respect to the target plate is calculated when the carrier reciprocates, and the calculated output voltage data Accumulate,
A displacement sensor correction method for a magnetic levitation transfer apparatus, characterized in that a computer that performs calculation processing corrects a performance difference between the displacement sensors.