JPH03198692A - Controller for multipole linear motor - Google Patents

Abstract

PURPOSE:To reduce thrust nonuniformity by deciding the magnitude and direction of lines of magnetic force which one coil will generate, considering detected results of other magnetic field detecting elements too provided in coils having definite position-relations to that coil. CONSTITUTION:When magnetic field detecting elements 4-i provided at specified positions of coils 3-i detect magnetic fields generated by magnets 7 being in a movable part 1 or a stationary part 2, the detected results are sent out to multiresult considering and drive directing sections 5-i. In the case of the multiresult considering and drive directing sections 5-i deciding lines of magnetic force which the coils 3-i will generate, they decide the magnitude and polarity (direction) of the lines of magnetic force which the coils 3-i will generate by using not only the detected results by the magnetic field detecting elements 4-i provided in specified positions of the coils 3-i, but also those obtained by magnetic field detecting elements provided in specified positions of coils other than these coils 3-i.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial application fields (Figures 3 and 4) Prior art (Figure 11) Problems to be solved by the invention (Figures 11 and 12) To solve the problems Means (Fig. 1) Effect (Fig. 1) Example (Figs. 2 to 10) Effects of the invention [Summary] The invention has a fixed part and a movable part that is movable along the fixed part, and has a fixed part or a movable part. A plurality of magnet parts whose polarity is alternately reversed at regular intervals are provided on either side of the magnet part, and a plurality of coils are provided on the other side to generate lines of magnetic force in the forward or reverse direction at predetermined intervals determined by the interval. , regarding a control device for a multipolar linear motor, which has a magnetic field detection unit that detects a magnetic field generated by a magnet unit provided at a predetermined position of each coil, and each drive unit that drives generation of magnetic lines of force in each coil. The purpose is to provide a multipolar linear motor control device that prevents thrust unevenness and generates coil thrust smoothly and efficiently. The configuration includes a multiple result-based drive instruction unit that makes decisions based on the detection results of the installed magnetic field detection unit and the magnetic field detection units installed in other coils that are in a certain positional relationship with the coil, and instructs the drive unit. .

[Industrial application field]

The present invention relates to a control device for a multipolar linear motor such as a coil movable multipolar linear motor, and particularly includes a fixed part and a movable part movable along the fixed part. One of the parts is provided with a plurality of magnet parts whose polarity is alternately reversed at regular intervals, and the other part is provided with a plurality of magnet parts that generate lines of magnetic force in the forward or reverse direction at predetermined intervals determined by the said interval. The present invention relates to a control device for a multipolar linear motor, which includes coils, a magnetic field detection section that is provided at a predetermined position of each coil and detects a magnetic field generated by a magnet section, and each drive section that drives each of the coils.

Compared to the method of converting the rotational force of a rotary motor into linear motion using a ball screw, the method of obtaining direct linear thrust using a linear motor is: ■ Non-contact driving is possible, so there is no dust generation or accuracy deterioration. It is widely used in precision mechanisms and orthogonal industrial robots because it has the following characteristics: ■ Suitable for high-speed drive; and ■ High natural frequency due to direct drive. In particular, as shown in Figure 4, a single-sided multi-polar linear motor (movable coil type) in which the coil is fixed to one yoke has two advantages: ■ There is no need to use a coil bobbin with low rigidity, and ■ The magnet and coil can be separated. Therefore, it is characterized by easy maintenance.

Furthermore, among single-sided multipolar linear motors, the magnet movable type as shown in Figure 3 has the following characteristics: 1) There is no need to supply electricity to the moving part, and 2) It requires fewer expensive magnets. Most of the types use a movable magnet type.

[Conventional technology]

Conventionally, there has been a control device for a multipolar linear motor as shown in FIG.

As shown in the figure, this device has a fixed part 112 and a movable part 111 that is movable along the fixed part 112, and the movable part 111 has a polarity that is alternately reversed at regular intervals. A plurality of permanent magnets 117 are provided, and a plurality of racetrack coils 113-i (i=1.2 ) is provided at the center of one side of each racetrack type coil 113-i as a predetermined position, and a permanent magnet 117 is provided.
Hall element (
or magnetoresistive element) 114-i, and each of the coils 11
3-i. Further, for each coil 113-i, the coil 11
Hall element 114 of each car provided corresponding to 3-i
-i determines the magnitude and polarity of the magnetic field lines to be generated by the coil 113-i, and
Single result consideration drive instruction unit 115-i that instructs 16-i
and a drive section 116-i.

[Problem to be solved by the invention]

By the way, in conventional magnet movable linear motors, in order to reduce power consumption and obtain thrust in the same direction, a magnetic field is detected at the center of one side of a racetrack type coil 113-i as shown in FIG. A Hall element 114-i and a single result-based drive instruction section 115-i are provided, and based on the output signal, the current flowing through the racetrack type coil on which the Hall element is mounted is set to 0N10FF, and the direction of the current is reversed. ing. That is, each coil 113-i has a corresponding Hall element 114-i, and the current of that coil is increased or decreased according to the output of the Hall element 114-i corresponding to its own coil 113-i. .

However, in the case of the racetrack type coil 113-i as shown in FIG. If the Hall element is not on the magnet side, it may not be detected that the coil 113-i enters the magnetic field.

For this reason, even though each coil 113-i should normally flow a current and generate thrust if even one side of it enters a magnetic field, the Hall element does not detect this, so no current flows and this occurs. The coil will not generate thrust.

Therefore, thrust is not generated even though it should be generated, resulting in uneven thrust. Especially when the number of thrust generating coils is small,
If even one coil does not generate thrust, this will result in large thrust unevenness in the linear motor, which will impede control transmission and smooth speed control during positioning control. In addition, when Hall elements are provided on both sides of a racetrack-type coil, there are problems in that the number of parts increases, the electrical wiring from the Hall elements becomes complicated, and the number of assembly steps increases. Ta.

Therefore, even when the number of magnetic field detection parts (Hall elements) to be arranged in each coil is set to one, the present invention prevents the occurrence of uneven thrust of each coil, and smoothes the thrust of the coil.
The purpose of this invention is to provide a multipolar linear motor control device that can efficiently generate power.

[Means to solve the problem]

In order to solve the above problems, the present invention has a fixed part 2 and a movable part 1 that is movable along the fixed part 2, as shown in FIG. 1, so that the polarity is alternately reversed at regular intervals,
A plurality of magnet parts 7 are provided, and on the other hand, a plurality of coils 3-i generate lines of magnetic force in the forward or reverse direction according to instructions at predetermined intervals determined by the above-mentioned intervals; i=1.2. ...
A magnetic field detection section 4-i, which is provided at each predetermined position of each coil 3-i and detects the magnetic field by the magnet section 7, and each drive section 6-i which drives each of the coils 3-i. In a control device for a multipolar linear motor having
The size and polarity of the magnetic lines of force to be generated are determined by the coil 3.
-i and the coil 3-i provided in the magnetic field detection section 4-i.
It is determined based on the detection result of the magnetic field detection unit 4-j provided at another coil 3-j; j≠i which has a certain positional relationship with i; A drive instruction unit 5-i that takes into account multiple results is provided.

(Function) When controlling the linear motor according to the present invention, the magnetic field generated by the magnet part 7 in the movable part 1 or the fixed part 2 is provided at a predetermined position of a certain coil 3-i. When detected by the magnetic field detection section 4-i, the detection result is sent to the multiple result reference drive instruction section 5-i.

The multiple result consideration drive instruction unit 5-i is the coil 3-i.
When determining the lines of magnetic force to be generated, the coil 3-i
In addition to the detection result by the magnetic field detection unit 4-i provided at a predetermined position of the coil 3-i,
; The magnitude and polarity ( direction).

In this way, when determining the magnitude and polarity of the magnetic field line to be generated by the coil 3-i, not only the detection result by the magnetic field detection unit 4-i provided in the coil 3-i but also the detection result by the magnetic field detection unit 4 The reason why the detection results of the magnetic field detection unit 4-j other than -i are used is as follows.

That is, each magnetic field detection section 4-i can detect a magnetic field when the magnet section reaches the vicinity of the predetermined position where the detection section 4-i is provided. Therefore, depending on the position of the movable part 1, even if the magnetic field is not detected by the detecting part 4-i, a line of magnetic force of an appropriate size and direction may be generated from the coil 3-i in response to the magnetic field by the magnet part 7. By generating the Lorentz force, it may be possible to apply a propulsive force to the movable part 1. This is to distinguish between cases where the coil 3-i cannot provide any propulsive force to the movable part 1 in such a case, and to efficiently provide propulsive force to the movable part 1.

Here, the "predetermined position" is a position where the magnetic field detection section determined for each coil is provided, and is, for example, the center of one side of a racetrack type coil.

The "certain positional relationship" is a positional relationship determined by the length of the movable portion 1, the constant interval at which the polarity is reversed, the predetermined interval between the arranged coils 3-i, and the like.

For example, when the movable part 1 is provided with the magnet part 7, there is a case where the magnetic field detection part 4-i of a certain coil 3-i does not detect a magnetic field, and the coil 3-i is In order to recognize the case where there is a possibility of giving thrust to the coil 3-i (that is, when the end of the movable part 1 is applied to the coil 33-1), it is necessary to 1 detects the magnetic field due to the movable part 1, and the first magnetic field detecting part that exceeds the full length does not detect the magnetic field, which is recognized.

(Example) Next, examples of the present invention will be described.

FIG. 2 shows an overall view of the multipolar linear motor according to this embodiment.

As shown in FIG. 1, the multipolar linear motor 20 according to this embodiment has a stage movable section 2 on which experimental equipment and the like are placed.
1, a multipolar linear motor movable part (hereinafter referred to as "movable part") 31, a multipolar linear motor fixed part (hereinafter referred to as "fixed part") 32, and a stage fixing part 24 according to the present embodiment.
and a linear guide guide 23 that guides the movable part 31 so that the linear motor movable part 31 moves along the fixed part 32.

Furthermore, the movable part 31 and the fixed part 32 according to this embodiment
This will be explained with reference to FIG.

As shown in the figure, the multi-pole linear motor according to this embodiment is a one-sided type (a type in which the permanent magnet is located only on one side of the coil, not on both sides of the upper and lower sides, that is, only on one side, either the top or the bottom), and has a fixed part. 32, and a movable part 31 that is movable along the fixed part 32, and the movable part 31 has permanent magnets 31b as a plurality of magnet parts 7 so that the polarity is alternately reversed at regular intervals. It also has a yoke 31a.

The fixed part 32 includes a plurality of racetrack-shaped coils 33-i that generate lines of magnetic force in the forward or reverse direction according to instructions at predetermined intervals determined by the interval.
1.2+..., and each coil 33-1
It has a Hall element 34-1 as a magnetic field detection section 4-i that is provided at the center of one side of each coil as a predetermined position and detects the presence or absence and polarity of the generated magnetic field. Here, the reason why the Hall element is provided only at the center of one side of each coil is to reduce the number of Hall elements as much as possible.

Further, the fixed portion 32 has a yoke 32a made of pure iron.

Furthermore, as shown in FIG. 5, the linear motor includes a drive section 36-1 that drives the coil 33-1;
The magnitude and polarity of the magnetic lines of force to be generated by the coil 33-1 are determined by the Hall element 34-1 provided in the coil 33-1.
The determination is made by taking into consideration not only the detection results of the coil 33-1 but also the detection results of the Hall elements 34-j; A multi-result consideration driving instruction unit 35-1 is provided.

Here, the term "certain positional relationship" refers to the length of the movable part 1, and each racetrack type coil 33-i arranged at a constant interval with the polarity reversed; i = 1.2.3... This is a relationship determined by the predetermined interval, etc.

For example, when focusing on a certain coil 33-1 as shown in FIG.
-6 Hall element 34-6 and the coil 33-6
Using the detection result of the Hall element 34-7 of the coil 33-7 adjacent to the Hall element 34-6, determine the lines of magnetic force to be generated in the coil 33-1 where the Hall element 34-1 is installed. That's what I do.

As shown in FIG. 5, the detection results of the Hall element 34-1 are input to the multi-result reference drive instruction section 35, and the HI/
By inputting the detection results of the comparators 35-1a and 35-1b, which convert into LO TTL signals, and the Hall element 34-6 of the other coil 33-6 in the fixed positional relationship, the HI/LO signal is generated. A comparator 35-1e inputs the detection results of the other Hall element 34-7 having a certain relationship with the comparators 35-1c and 35-1d, which convert the signals into HI/LO signals.
and comparator 35-1f, and each Hall element 34
-1.34-6°34-7, and a microcomputer 35-1g for inputting determination results regarding 34-7 to obtain instruction signals for the drive section 36-1.

The comparator 35-1e (the same applies to a and c)
As shown in FIG. 6, comparators 35-1el and 35-
1e2, AND element 35-1e3, and variable resistors 35-1e4, 35- for determining the reference voltage at each comparison.
1e5, each of the positive/negative determination comparators 35-1
b, 35-1d, and 35-1f have comparators with a reference voltage of O.

5. The Hall element 34-1.34-6.34-7 also includes a buffer 734-11.34-61.34-71 for amplifying data indicating the detection results of each element.

Further, the drive section 36-1 includes an analog switch 36-1a for controlling the current 0N10FF, a current direction reversing circuit 38-ie for controlling the direction of the magnetic lines of force, and a signal having a predetermined current value for changing the voltage value. It has a power amplifier 36-1d that performs amplification. The current direction reversing circuit 36-
ie is the sign inversion circuit 36-1b and the analog switch 3
6-1c.

In addition, although the case where the magnetic field lines to be generated for the coil 33-1 are determined is explained above,
The same applies to

Next, the operation of the linear motor control device according to this embodiment will be explained.

As shown in the flowchart of FIG. 10, in step S1, the microcomputer 35-1g of the drive instruction section 635-1 determines whether or not there is an output from the Hall element 34-1 provided in the fixed section 32. do.

When there is a HI signal (ON state) from the Hall element 34-1 via the window comparator 35-1a, the Hall element 34-1 is transmitted as shown in FIG. 8(a).
1 exists in the magnetic field of the movable part 31. In this case, proceed to step S8 and turn the analog switch to
Set to N state.

Furthermore, the process proceeds to step S9, and in order to determine the direction of the magnetic field lines to be generated by the coil 33-1,
Among the detection results of 4-1, the output result of the positive/negative determination comparator 35-1b is looked at.

If the output result is positive, the process proceeds to step Sll and the analog switch 36-1c is connected to the positive side. On the other hand, if the output result is negative in step S9, the process proceeds to step SIO, the analog switch 36-1c is connected to the negative side, and the process returns to the beginning again.

On the other hand, when the magnetic field of the Hall element 34-1 is not detected as shown in FIG. 7, the cases shown in FIGS. 8(b), (C) and 9(a), (b) are exist.

Therefore, in order to distinguish between these cases, in this embodiment, the process proceeds to step S2 and the output result of the Hall element 34-6 is examined.

That is, when there is an output from the Hall element 34-6, the eighth
There are only cases shown in Figures (b) and (C). Therefore, in order to distinguish between these cases, the process proceeds to step S4 and the Hall element 3
It is determined whether there is an output from 4-7.

When there is an output from the Hall element 34-7, as shown in Fig. 8 (
In the case corresponding to b), the movable part 31 has not reached the coil 33-1, so step S1
Proceed to step 2, and set O to the analog switch 36-1a.
The FF will be instructed.

On the other hand, if there is no output from the Hall element 34-7 in step S4, the case corresponds to FIG. 8(C), and the process proceeds to step S5, where the analog switch 36-1a
is set to ON state.

At that time, the polarity of the magnetic field of the Hall element 34-6 described above is determined, and if the polarity is positive, step S1
3, the analog switch 36-1c is connected to the negative side, and if the polarity is negative, the process proceeds to step S7, where the analog switch 36-1c is connected to the positive side.

On the other hand, if there is no output from the Hall element 34-6 in step S2, this corresponds to FIG. 9(a) or (b), and the movable part 31 is not applied to the coil 33-1. Proceeding to step S3, the analog switch 36-1a
is set to OFF state.

In the above explanation, the reason why the sign of the control signal is inverted by determining whether the Hall element 34-6 is positive or negative is that the control input is inverted compared to the case where the sign of the Hall element 34-1 is determined. This is because the sign of the Hall element is reversed.

In the above explanation, a single-sided multi-pole linear motor with a movable magnet has been explained, but the invention is not limited to this example, and a single-sided multi-polar linear motor with a movable coil as shown in FIG. can be similarly applied.

In this example, permanent magnets 43a are arranged at regular intervals on the fixed part 43 and fixed by a yoke 43b, and a plurality of coils 41a are arranged in the movable part 41 and also fixed by the yoke 41b.

(Effects of the Invention) As explained above, in the present invention, the magnitude and direction of magnetic lines of force to be generated by one coil are not determined based only on the detection results of the magnetic field detection section provided in the coil, but The determination is made by also taking into account the detection results of other magnetic field detection units provided in coils that are in a certain positional relationship with the coil.

Therefore, even if the magnetic field detection unit installed in the coil of interest does not detect a magnetic field, the detection results from the magnetic field detection units of other coils that are in a certain positional relationship considering the length of the movable part etc. Taking into account the above, if it is possible to apply a propulsive force to the movable part by the coil, it is possible to apply thrust to the movable part, reduce thrust unevenness, prevent control oscillation, and achieve smooth speed control, etc. This can contribute to improving the performance of

[Brief explanation of drawings]

Fig. 1 is a principle block diagram of the present invention, Fig. 2 is an overall view of a multi-polar linear motor according to an embodiment, and Fig. 3 is a diagram showing a multi-polar linear motor (movable magnet type) according to an embodiment. , 4th
The figure shows a single-sided multipolar linear motor (coil movable type) according to the embodiment, FIG. 5 is a block diagram of the equipment configuration showing the linear motor according to the embodiment, and FIG. 6 shows the linear motor according to the embodiment. 7 is an explanatory diagram of the operation of the linear motor according to the embodiment, FIG. 8 is an explanatory diagram of the operation of the linear motor according to the embodiment, and FIG. 9 is an explanatory diagram of the operation of the linear motor according to the embodiment. FIG. 10 is a flowchart showing the operation of the linear motor according to the embodiment, FIG. 11 is a block diagram according to the conventional example, and FIG. 12 is an explanatory diagram of the operation of the linear motor according to the conventional example. 1.31... Movable part 2.12... Fixed part 3-i, 33-i... Coil 4-i (34-i)... Magnetic field detection part (Hall element) 5-i, 35 -i...Multiple result consideration drive instruction unit 6-i
, 36-i... Drive section 7 (31b)... Magnet section (permanent magnet) 9.39...
Raceway surface (0) (b) (C) (0) Diagram 9wI of the operation of the linear motor 9 that is suitable for emergency applications

Claims (1)

[Claims] It has a fixed part (2) and a movable part (1) movable along the fixed part (2), and the fixed part (2) or the movable part (
1), one of them is provided with a plurality of magnet parts (7) whose polarity is alternately reversed at regular intervals, and the other is provided with a plurality of magnet parts (7) whose polarity is alternately reversed at regular intervals, and the other is provided with lines of magnetic force in the forward or reverse direction at prescribed intervals determined by the intervals. A plurality of coils (3-i; i=1, 2,
...), and a magnetic field detection section (4-i) that is provided at each predetermined position of each coil (3-i) to detect the magnetic field by the magnet section (7), and In a control device for a multipolar linear motor having each drive unit (6-i) that drives the generation of magnetic lines of force, the magnitude and polarity of the magnetic lines of force to be generated by each coil (3-i) are controlled by the coil (3-i). -i) Magnetic field detection unit (
4-i) and the detection results of the magnetic field detection unit (4=j; j≠i) provided in another coil (3-j; j≠i) that has a certain positional relationship with the coil (3-i) Decided based on
A control device for a multi-polar linear motor, characterized in that a multi-result-based drive instruction section (5-i) is provided for instructing the drive section (67-i).