JPS6186811A - Step feed actuator device having variable stop position - Google Patents

Abstract

PURPOSE:To stop an actuator device at an optional position and also to attain the miniaturization and high working efficiency of said device by providing a sensor at a position opposite to a mobile part for the generation of an n-phase output. CONSTITUTION:A sensor 3A is set opposite to the mobile part 2A of an actuator and produces outputs A and B of two phases different from each other by 90 deg.. A signal processing circuit 6A produces signals (a) and (b) and their adversely converted signals (-a) and (-b) according to both outputs A and B of the sensor 3A. An electric current command circuit 5A selects just one of those signals (a), (b), (-a) and (-b) sent from the circuit 6A based on the commands thetaP and thetar given from a command production circuit 7A. Thus a current command signal iC is produced according to the signal selected by the circuit 5A. A stop position varying circuit 8A changes the bias of the signal iC and produces a correction current command signal iCO. A current control circuit 4A controls the current (i) of a fixed part 1A or the part 2A of the actuator based on the signal iCO. Thus the direction and the level of the current of the actuator are decided by the signals (a), (b), (-a) and (-b) obtained by the outputs A and B of the sensor 3A.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a variable stop position step feed actuator device, which can move the position arbitrarily in steps, and which is small and highly accurate. The present invention relates to a step feed actuator device.

[Background of the invention]

The recent development of the information industry has been remarkable.

In particular, OA (Office Auhiomat, 1o
n) Rapid progress is being made in equipment in response to the need for labor-saving and resource-saving.

For example, as the density of FDDs increases, it is essential for actuator devices that drive heads of floppy disks (FDDs) to reduce track spacing and improve stopping accuracy.

Conventionally, in order to meet the above-mentioned high precision for driving the head, it has been necessary to increase the number of teeth on the iron core of the step motor.

However, if this is done, the pitch of the teeth becomes small, making machining difficult, and the precision with respect to the pitch also deteriorates.

Furthermore, when the pitch of the teeth becomes small, torque generation and lagtance changes related to torque inclination become small, so the generated torque also becomes small.

In response to this, a method has recently been announced in which a feedback signal is recorded on the disk surface of the FDD using a coil movable actuator, and the servo is controlled by this signal, but this method is different from the disk method. There was a drawback that there was no compatibility and it was difficult to use as a general-purpose actuator device.

Incidentally, related devices of this type include, for example, the device described in Japanese Patent Publication No. 18957/1983.

[Purpose of the invention]

The present invention provides a variable stop position step feed actuator device that is small and enables highly accurate step feed.
That is the purpose.

[Summary of the invention]

The first aspect of the variable stop position step feed actuator device of the present invention includes an actuator including a fixed part and a movable part, and a sensor that is opposed to the movable part and generates an output of each phase. In such a device, a sensor that generates two-phase outputs A and B is provided as the sensor, and a signal a related to the sensor outputs A and B is provided.
,b and.

An inversely converted signal e based on the sensor outputs A and B.

a current command circuit that sequentially selects one of the signals at b, a, and b to generate a current command based on the position command; A current control circuit that controls the current, and a stop position variable circuit that changes the bias of a certain signal based on the sensor output based on the position command, generates a corrected signal, and makes it possible to stop at any position. It is constructed by providing the following.

Further, a similar configuration of the second invention is such that an actuator including a fixed part and a movable part is provided, and a sensor that generates eight forces of each phase is provided facing the movable part. A current command circuit is provided with a sensor that generates n-phase (n≧3) outputs as a sensor, and generates a current command by sequentially selecting one of the n signals based on a 1-position command. , a current control circuit that controls the actuator current based on the current command, and a current control circuit that controls the current of the actuator based on the current command, and
It is constructed by including a stop position variable circuit that varies the bias of a certain signal based on the sensor output, generates a corrected signal, and makes it possible to stop at any position.

More detailed information is as follows.

According to the present invention, an operation corresponding to the teeth of a step motor is achieved by a sensor and a control circuit, and the stop position can be arbitrarily varied.

That is, the sensor generates a number of outputs corresponding to the number of steps of the step motor, for example, two-phase output A,
A sensor that generates B (for example, for a 1.8' step motor, a two-phase sensor with 36 o/1.8 One of the signals a and b related to the phase outputs A and B and the inversely converted signals a and b of the same outputs A and B is sequentially switched in synchronization with the command pulse. be.

The bias of the selected sensor output signal is then made variable in response to that signal.

This is designed to control the winding current of the actuator.

Since the step operation is based on the sensor signal, the torque generation mechanism of the actuator does not require teeth like a step motor, and the sensor and control circuit perform the action of the step motor's teeth. It is.

The block diagram in FIG. 1 shows the basic configuration of a variable stop position step feed actuator device based on the above idea.

In the figure, IA is the fixed part of the actuator, 2A is the movable part of the actuator, and 3A is the movable part 2A of the actuator.
It was installed opposite to. Two-phase output A with a 90 degree phase difference
, B.

6A is a signal processing circuit that generates signals a, b and their inversely converted signals a, b based on the two-phase outputs A and B of the sensor 3A, and 7A is a command generation circuit.

5A is a command θ2゜θ from the command generation circuit 7A, (in addition, the command θ is a pulse train related to the number of steps, and the same θ is
This is a command for the direction of movement. ), the signal processing circuit 6A
Each signal a, b, a.

This is a current command circuit that sequentially selects only one from b and generates a current command signal ic based on it.

8A varies the bias of the current command signal IC,
This is a stop position variable circuit that generates a correction current command signal ice.

Although it was around 1, 4A is the above correction current command signal +
This is a current control circuit that controls the coil current i of the fixed part 1, A or the movable part 2A of the actuator based on co.

According to the above configuration, the direction and magnitude of the current in the actuator are determined by the signals a and b from the two-phase outputs A and B of the sensor 3A, and the inversely converted signals a and b.

FIG. 2 is an explanatory diagram of the relationship between the sensor output and basic operation, showing the phase relationship of each signal at by at b.
, b (ilB)fb (ilB) are the signals a
, a, b, b, and at the same time, each signal a, a
, b, shows the phase of the actuator coil current i based on b.

In this figure 2, if the current in the positive direction generates a force in the right direction, and the current in the negative direction generates a force in the left direction, then the position (a) to the left of point a1 In the region, it always moves to the right, and in the region of phase (b) to the right of point a1, it always moves to the left and stops at point a.

Further, in the area of the position (c) to the left of point a2 in the figure, it moves to the right and stops at point a2 based on the same idea.

That is, when the signal a is based on the output A of the sensor 3A, points a, la21, . . . are stable points, and the motor always stops at these positions.

Similarly, a point aI for the inversely transformed signal a, a point bl for the signal, and a point for the inversely transformed signal are stable points.

From this diagram, when moving the actuator to the right,
As shown in the figure, the signal is a→b-+a→b-
+a, and conversely, when moving to the left, as shown by the dashed arrow, a+b-+a-+b
→It is switched as shown in a.

That is, if the movable part 2A is now at the position of point a based on the signal a, then when moving to the next signal, the current command signal ic increases from zero at the point a1 to ill+.

As a result, the movable part 2A moves rightward and stops at the turn.

Next, when moving to the inverse conversion signal a, the current command signal ie increases from zero at point b1 to i again, and the movable part 2A moves rightward and stops at point a1.

By repeating this operation, to the right, a, → b,
It is possible to move any number of steps in the order of →a, →b, →a1.

The same applies to the left direction.

FIG. 3 shows a certain one-phase waveform related to the sensor output,
It is an explanatory diagram of the relationship between the sensor output and the bias, and this also shows the waveform of the actuator coil current i.

In Fig. 3, if the current in the positive direction generates a force in the right direction, and the current in the negative direction generates a force in the left direction, then when the zero level is AL, point a position on the left side of (a)
In the area, it always moves to the right and reaches the position to the right of point a (
In the area b), it always moves to the left and stops at point a.

Also, when a bias is applied and the zero level changes to BL, the area at the left position (c) of the dot always moves to the right, and the area at the right position (d) of the dot always moves to the right. Move to the left and stop at point b.

Furthermore, when a bias is added and the zero level changes to CL, the area at position (E) to the left of point C will always move to the right, and in the area at position If (to) to the right of point C, it will always move to the right. , always move to the left and stop at the 0 point.

That is, by changing the zero point of the signal based on the output of the sensor 3A, the stable point becomes the point at b+C2...
It changes like this and always stops at that position.

In this way, by applying a bias to the signal based on the output of the sensor 3A, changing the zero point, and switching the signal as described in FIG. 2, step feed that can be stopped at any position is possible.

Therefore, the actuator may be anything that changes the direction of force depending on the direction of the current, and includes most electromagnetic machines. For example, a DC motor is used in a one-rotation machine, and a voice coil is used in a linear actuator.

Further, the sensor includes a rotary encoder in the case of a rotating machine, a linear encoder in the case of a linear actuator, and the like.

As can be seen from the above-mentioned Fig. 2, there are four possible stopping points in one cycle: a, I l l b, l b, and it is clear that the stopping accuracy depends on the sensor accuracy. .

Furthermore, the sensor waveform may be shaped into a triangular wave in order to reduce the error caused by the load at the stopping point.

Furthermore, the sensor output is 3
It may be of n-phase (n≧3) including those of three phases.

[Embodiments of the invention]

Each embodiment of the actuator device for variable stop position step feeding according to the present invention will be described with reference to each embodiment.

First, FIG. 4 is a schematic configuration diagram of a variable stop position step feed actuator device according to an embodiment of the present invention, and FIGS. 5, 6, and 7 are time charts for explaining its operation. be.

According to this embodiment, an actuator including a fixed part and a movable part is provided, and a sensor for generating an output of each phase is provided facing the movable part. A sensor that generates phase outputs A and B is provided, and signals a and b related to the sensor outputs A and B are provided.

An inversely converted signal a based on the sensor outputs A and B.

a current command circuit that sequentially selects one of the signals a, b, a, and b based on the position command to generate a current command; and a bias for the current command. The stop position variable circuit is configured to include a stop position variable circuit that varies the current and generates a correction current command, and a current control circuit that controls the current of the actuator based on the correction current command.

That is, in FIG. 4, 11 is a coil movable linear actuator, which has a permanent magnet 112 and a magnetic pole piece 116 on the inner surface of a fixed part 111.

A coil 115 is disposed in the gap between these, and thrust is generated by the coil current and magnetic flux.

The movable part 113 directly connected to the coil 115 is
It is supported by a sliding bearing 114 and can move left and right.

Therefore, in order to detect the position of the movable part 113, the sensor 3 is disposed facing the movable part 113.

This sensor 3 is a magnetoresistive element, and the movable part 11
The position can be measured by the increase or decrease in the magnetic field of the magnetic pole of the magnetic paint 117 applied to the magnetic paint 117.

Therefore, the movable part 113 of the linear actuator 11 in this configuration can linearly move left and right by passing positive and negative currents through the coil 115, and with respect to this linear movement, Sensor 3 is
Generates two-phase outputs A and B with a 90 degree phase difference.

6 is based on the two-phase outputs A and B of the sensor 3, and generates the previously mentioned signals a, b,
Create reverse conversion signals a and b, and each of these signals a, b, a,
This is a signal processing circuit that outputs b.

7 is a command generation circuit; 5 is a signal a from the signal processing circuit 6 based on the command from the command generation circuit 7;

A current command circuit 8 selects only one from b, a, and b and generates a current command signal ic based on it; 8 generates a signal from the current command circuit 5 based on a command from the command generation circuit 7; This is a stop position variable circuit that varies the bias of 10 and generates a correction current command signal IC6.

This current command circuit 5 is composed of an UP/DOWN counter 52 and an analog multiplexer 51. According to the command θ and the movement direction command θ, an UP or DOWN count is performed, and the address signal D0 is
．． D.

is generated.

Further, the analog multiplexer 51 outputs the address signal D
0. Based on D, only one of the four switches shown is closed; for example, based on the address signal, D
, the current command signal ic is the signal 11-*b4
B-) It is switched as in 1).

4 is a current control circuit that controls the current of the coil 115.

That is, 21 is a DC power supply, 23 to 26 are transistors connected in an H type, and the transistors 23 and 26 are
The direction of the coil current is controlled by turning ON or 24.25, and the magnitude of the coil current is controlled by the energization rate. 22 is a current detector that detects the coil current. be.

8 is a current command signal iC and a stop position signal kc.
I is calculated by the amplifier 81 to obtain a corrected current command i. . This is a variable stop position circuit that generates

Further, 82-1 is a position command θ. This is a stop position signal generation circuit that generates a stop position signal tc+ based on the following.

9 is a corrected current command signal tco and coil current detection value i,
This is a pre-drive circuit that generates firing signals for the transistors 23 to 26 groups.

In this predrive circuit 9, a correction current command signal t
co and the coil current detection value i are calculated by the amplifier 32, and this output S. is the triangular wave St from the triangular wave generating circuit 10
are compared by the comparator 29.

The triangular wave generating circuit IO is composed of two amplifiers 30 and 31, and generates a triangular wave by charging and discharging a capacitor 35.

This triangular wave signal St and the output S of the amplifier 32. The duty output Sd can be obtained by matching with the above.

The signal related to this duty output S is output from the AND circuit 27.2.
8, and this AND circuit 27.28
The other input of the current command signal ICO is determined by the comparator 34 as to whether it is a positive direction or a negative direction, and is inputted to the AND circuit 27.
It is input through the T circuit 33.

Therefore, transistors 23 and 26 are turned on when the direction is positive, and transistors 25 and 24 are turned on when the direction is reversed.

With the above configuration, following the command of the command generation circuit 7,
The linear actuator 11 is capable of step feeding.

This can be explained using the time charts shown in Figures 5, 6, and 7.
This will be explained in more detail.

In FIG. 5, θ2. As mentioned above, θ1 is a command from the command generation circuit 7, θ is a pulse train command that commands the number of steps to feed, and θ is a command for the direction of movement. In the figure, 1 is a rightward direction, and zero is a leftward direction. It is.

Further, S is the signal name selected by the current command circuit 5, ic
o is the output IC of the current command circuit 5 and the stop position signal IC
If the operating speed of the predrive circuit 9 and the current control circuit 4 is sufficiently fast, the coil current detection value i is also the correction current command signal calculated by the above output i.
is approximately equal to co. (2) indicates the speed of the movable portion 113 of the linear actuator 11, and X indicates the position of the movable portion 113.

That is, from time 10 to t1, signal a related to the A-phase output from sensor 3 is selected and stopped at a stable point of signal a.

Next, at time t1, when the pulse signal P1 related to the pulse train command θ2 is input, the signal related to the output B from the sensor 3 is selected, the current command signal ic becomes a positive value, and the coil current becomes Following this, the flow begins, and the movable part 113 begins to move.

Next, when the pulse signals P2 to P4 are input at times t2 to t4, the sensor 3 selects each signal a, b, and a in this order, and the movable part 113 moves as indicated by X in the figure. be.

Next, after a certain period of time from t4 to t6, the movable part 113 stops. At this time, the movable part 113 has moved four steps to the right.

Next, in the middle of 1 hour t4 to t5, the movement direction command θ becomes O, and when the pulse signal P5 is input at time 1S, the sensor 3 selects signals a to b, and the corrected current command signal ic
o becomes negative, the coil current also becomes reversed, and the movable part 113
It also begins to move to the left.

Next, when the pulse signal PiiTPヮ is input at time t@It7, the sensor 3 selects the signals a and b sequentially and waits for 1 hour t.
7, it will stop after a certain amount of time has elapsed.

As a result, it stops after moving three steps to the left.

Next, changes in the stop position will be explained with reference to FIGS. 6 and 7.

S shown in (a) of this figure 6 is the signal name selected by the current command circuit 5, and its vertical solid line and chain line correspond to the solid line and l line of the same figure (b) described below. It is something.

(il A)l b (il B)# b (it B
) respectively indicate the phase relationship of the signals at al b, b, and at the same time indicate the phase of the actuator coil current i based on each signal at at ht b.

Further, X shown in (c) of FIG. 6 indicates the position of the movable part 113.

If the bias is set like the zero level of the solid line AL shown in the figure, the transition from b→a-* in the same figure (A) as shown by the solid line arrow.
-+ a-e l), the movable part 11
3 is a stopping point like 1 point alta21...
Move in steps.

Also, as shown in the level of the f line BL shown in Figure 1, the b-
+a-+b-+a→b, the movable part 11
3 is the point bl ahead of the point alla21...
Move in steps at stopping points such as lb2t...

FIG. 6(c) shows the step transition process.

As a result, as shown in FIG. 7(b), the bias is changed for each phase, and b-+a in FIG.
-+b-+a-+b.

The movable part 113 moves stepwise at stopping points such as 9 points cl t C2P... In other words, it can be moved as shown in FIG.

In other words, conventionally, the step pitch was fixed, but
According to this embodiment, by arbitrarily changing the bias, the movable portion 113 can be stopped at an arbitrary position.

In this embodiment, the variable stop position circuit 8 is placed after the current command circuit 5, but the variable stop position circuit 8 is placed before or after the signal processing circuit 6.

In either case, the concept of the present invention can be effectively applied.

Next, a case will be described in which a variable stop position circuit is connected after the signal processing circuit.

That is, FIG. 8 is a schematic configuration diagram of a variable stop position step feed actuator device according to another embodiment of the present invention.

According to this embodiment, an actuator including a fixed part and a movable part is provided, and a sensor for generating an output of each phase is provided facing the movable part. A sensor that generates phase outputs A and B is provided, and signals a and b related to the sensor outputs A and B, and an inversely converted signal a based on the sensor outputs A and B.

a signal processing circuit that processes each of the signals a and b;

By varying the biases of b, a, and b, a correction signal a' is generated.

), j, a/, b/, and each of the above-mentioned signals a', b', a based on the position command.
'.

b', and a current control circuit that controls the current of the actuator based on the current command. The difference from the previous embodiment is that the variable stop position circuit 8-1 is connected after the signal processing circuit 6.

In the figure, the same reference numerals as in FIG. 4 according to the previous embodiment are
The equivalent ones are shown, 8-1 is a stop position variable circuit, 81-
1 to 81-4 apply a bias to the signals a, b, a, b based on the sensor signals using the stop position signal 10°, ~ico+, and generate correction signals a', b', a/
, b/.

Further, 82-2 is a position command θ. Based on the stop position signal ICO/'. . Stop position to generate ~! 〒 This is a signal generation circuit.

In other words, even if the variable stop position circuit 8-1 is connected after the signal processing circuit 6, as shown in FIG. This makes it possible to achieve the same effect.

Although each of the above embodiments has been explained using a two-phase sensor as an example, the concept of the present invention can also be effectively applied to a multi-phase sensor in order to increase the resolution of the sensor. .

Next, the case of the multiphase sensor will be explained.

That is, FIG. 9 is a schematic configuration diagram of a variable stop position step feed actuator device according to another embodiment of the present invention;
FIG. 10 is an explanatory diagram of the relationship between the sensor output and basic operation, showing the phase relationship of each signal, and FIG. 11 is a time chart diagram illustrating the operation of the variable stop position step feed actuator device.

According to this embodiment, an actuator including a fixed part and a movable part is provided, and a sensor for generating an output of each phase is provided facing the movable part. Sensors that generate phase (n≧3) outputs are provided, and n related to each sensor output is provided.
a signal processing circuit that processes 2n signals and n inversely converted signals based on the respective sensor outputs; Consisting of a current command circuit that generates a command, a variable stop position circuit that varies the bias of the current command and generates a corrected current command, and a current control circuit that controls the actuator current based on the corrected current command. and
n=3. That is, it is related to three phases.

In FIG. 9, the same reference numerals as in FIG. 4 according to the previous embodiment indicate equivalent components, 3-1 is a three-phase sensor, 5-1 is a three-phase sensor,
is a current command circuit, 51-1 is an analog multiplexer,
6-1 is a signal processing circuit, and 61 to 63 are analog inverters.

That is, in this embodiment, as shown in Fig. 9.10.
This is the case for three-phase sensors separated by degrees.

In the case of a three-phase sensor, outputs A and B of sensor 3-1.

If three-phase signals a, b, and c related to C are used, and inversely converted signals a, b, and c related to the inverted signals of each output A, B, and C of sensor 3-1 are used at the same time, every 60 degrees. This enables step feed with variable stop position.

In FIG. 10, points a, b, and c are stable points of the signals alb and C corresponding to the A phase.

Step feeding every 60 degrees can be performed by switching in the order of a-+c→b-+a→C→b→a, as shown by solid arrows in FIG.

Therefore, in this embodiment, each of the three-phase signals B, b
g C) & Hbr c are used at the same time, but in the case of this three-phase sensor, by using only the signals a, b, and c related to the outputs A, B, and C, it is possible to change the stop position every 120 degrees. The stop position variable step feed actuator device can perform variable step feed.

That is, in this case, the signal processing circuit 6-1 of FIG. 9 is not provided, and the six switches in the analog multiplexer 51-1 are connected to the signals a and b.

By configuring only three switches related to C,
The stop position can be changed in steps of 120 degrees.

Next, changes in the stop position will be explained with reference to FIG. 11.

S in this figure 11 is the signal name selected by the current command circuit 5-1, and its vertical solid line is the same figure (b) described below.
This corresponds to the solid line.

e (C), a (A), b (B), c
(C) represents each signal al bg Ce as be
At the same time, each signal at bl c,
It shows the phase of the actuator coil current i based on a, b, and c.

Further, X shown in (c) of FIG. 11 indicates the position of the movable portion 113.

In particular, when switching, the movable part 113 moves to the point alla21...
It is possible to move in steps at stopping points such as...

That is, as in the embodiment of the rabbit, by arbitrarily changing the bias, the movable portion 113 can be stopped at an arbitrary position.

In these cases, even when the polyphase is three or more phases, the configuration can be changed in the same manner and the same effect can be expected.

〔Effect of the invention〕

According to the present invention, an actuator device capable of variable stop position step feeding can be realized using a sensor and a control circuit without providing teeth on an iron core or the like. Therefore, by using a highly accurate sensor and varying the bias, it is possible to stop the actuator at any position and to realize an actuator device with an extremely fine step length.

Further, as the torque generating mechanism, a general one such as a DC machine or a voice coil can be used, and miniaturization and high efficiency can be achieved.

Furthermore, by changing the pitch of the sensor, the number of steps can be changed, and the mass productivity and versatility of the actuator device can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the stop position variable step feed actuator device according to the present invention, and FIG. 2 is an explanatory diagram of the relationship between sensor output and basic operation, showing the phase relationship of each signal. Figure 3 shows the sensor output.
FIG. 4 is a schematic diagram showing the configuration of a variable stop position step feed actuator device according to an embodiment of the present invention; FIG. 8 is a time chart diagram explaining the operation, and FIG. 8 is a schematic configuration diagram of another embodiment of the present invention.
FIG. 9 is a schematic configuration diagram of yet another embodiment of the present invention, FIG. 10 is an explanatory diagram of the relationship between sensor output and basic operation, also showing the phase relationship of each signal, and FIG. 11 is a time chart diagram illustrating the operation. 3.3-1...Sensor, 4...Current control circuit, 5,
5-1... Current command circuit, 6.6-1... Signal processing circuit, 7... Command generation circuit, 8.8-1... Stop position variable circuit, 9... Predrive circuit , 10...3
Angular wave generation circuit, 11... Coil movable linear actuator, 111... Fixed part, 112... Permanent magnet,
113...Movable part, 114...Sliding bearing, 115
... Coil, 116 ... Magnetic pole piece, 117 ... Magnetic paint, 21 ... DC power supply, 22 ... Current detector, 2
3-26... Transistor, 27.28... AND circuit, 29... Comparator, 30-32, 81.81-1
~81-4...Amplifier. 33...NOT circuit, 34...Comparator, 35
...Capacitor, 51.51-1...Analog multiplexer, 52...UP/DOWN counter, 61-63...Analog inverter, 82-1
゜82-2...Stop position signal generation circuit. Agent: Patent attorney Kosaku Fukuda (and one other person) Pa... - 1 figure, 2 figures, 2 figures, S figure, 6 areas, 1 figure, 18 figures, 9 figures, 11 figures.

Claims (1)

[Scope of Claims] 1. An actuator comprising a fixed part and a movable part, and a sensor that generates an output of each phase facing the movable part. A signal processing circuit that includes a sensor that generates outputs A and B, and processes signals a and b related to the sensor outputs A and B, and inversely converted signals a and b based on the sensor outputs A and B. and each of the above signals a, b, @a based on the position command.
A current command circuit that sequentially selects one of @ and @b@ to generate a current command, a current control circuit that controls the actuator current based on the current command, and a current control circuit that controls the actuator current based on the position command based on the sensor output. By varying the bias of a certain signal,
What is claimed is: 1. A variable stop position step feed actuator device comprising a variable stop position circuit that generates a corrected signal and can stop at any position. 2. An actuator consisting of a fixed part and a movable part, and a sensor that faces the movable part and generates an output of each phase. Provide a sensor that generates
a current command circuit that sequentially selects one of the n signals based on the position command to generate a current command; a current control circuit that controls the current of the actuator based on the current command; , a stop position variable circuit that varies the bias of a certain signal based on the sensor output, generates a corrected signal, and makes it possible to stop at any position. Variable step feed actuator device. 3. In the product described in claim 2, the n-phase (
a signal processing circuit that processes n signals related to each sensor output that generates an output of n≧3) and n inversely converted signals based on each sensor;
A current command circuit that sequentially selects one of the signals to generate a current command, a current control circuit that controls the actuator current based on the current command, and a current control circuit that controls the actuator current based on the position command and the sensor output. A stop position variable step feed actuator device is equipped with a stop position variable circuit that varies the bias of a certain signal, generates a corrected signal, and makes it possible to stop at any position.