JP2010207065A - Electromagnetic actuator, drive device for the electromagnetic actuator, drive method thereof and device mounted with the electromagnetic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device capable of highly precisely driving an electromagnetic actuator in at least two degrees of freedom, an electromagnetic actuator equipped with the same, a drive method thereof, and a device mounted with the electromagnetic actuator. <P>SOLUTION: A driving unit tilts a mover 1 by exciting the electromagnets of excited coils W at different current values while maintaining the polarities of the electromagnets after rotating the mover 1 around a z-axis or immediately before completion of the rotation thereof. Alternatively, the driving unit 5 tilts the mover 1 by exciting coils (U<SB>1</SB>, V<SB>1</SB>) and coils (U<SB>2</SB>, V<SB>2</SB>) at different current values while maintaining the polarities of the electromagnets of the excited coils W after rotating the mover 1 around the z-axis or immediately before completion of the rotation thereof. That means, since the mover 1 is driven so as to be tilted while being positioned along a circumferential direction, the mover 1 can be highly precisely driven at least in two degrees of freedom. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic actuator that is driven using electromagnetic action, a driving device that drives the electromagnetic actuator, a driving method thereof, and a device equipped with the electromagnetic actuator.

  2. Description of the Related Art A structure having a plurality of one-degree-of-freedom actuators is often used as a device that realizes driving with two or more degrees-of-freedom applied in industrial robots or humanoid robots. Such an actuator provided with a plurality of one-degree-of-freedom actuators has problems such as an increase in the size of the device. Thus, there is an actuator that can be driven with three degrees of freedom with one movable element (see, for example, Non-Patent Document 1).

  The actuator described in Non-Patent Document 1 includes a mover whose side surface is configured as a part of a spherical surface, and a stator having a plurality of electromagnets arranged around the mover. The mover is magnetized such that a plurality of magnetic pole pairs are arranged in the circumferential direction. The plurality of electromagnets of the stator are arranged in two upper and lower stages, six electromagnets are arranged in the upper stage, and six electromagnets are also arranged in the lower stage. The surface of the plurality of electromagnets facing the side surface of the mover (end surface of the core) is a spherical surface. In the actuator configured as described above, each of the twelve electromagnets is excited to a predetermined pole so that the mover moves in the circumferential direction in which the plurality of magnetic pole pairs of the mover are arranged (in the x and y axis horizontal planes). ) Rotate or swing in the vertical direction (z-axis direction).

The Institute of Electrical Engineers of Japan LD-08-46 "Study on 3-DOF Spherical Electromagnetic Actuators" Toshihiro Kajima, Atsushi Yamamoto, Katsuhiro Hirata

  As shown in FIG. 2B, the actuator described in Non-Patent Document 1 is located at a position 180 ° away from the z axis when the mover is rotated around the x or y axis. The electromagnets are excited so that the two electromagnets have opposite poles. However, the magnetic poles at positions 180 ° apart about the z-axis of the mover are predetermined so as to be the same pole. Therefore, when the actuator tries to rotate the mover around the x or y axis, there is a possibility that the rotation cannot be reliably controlled at a predetermined rotation angle around the z axis.

  In view of the circumstances as described above, an object of the present invention is to provide at least rotation of the electromagnetic actuator in the circumferential direction in which the magnetic poles of the mover are arranged and rotation (tilting) in at least one direction different from rotation in the circumferential direction. It is an object of the present invention to provide a driving device that can be driven with high accuracy with two degrees of freedom, an electromagnetic actuator device including the driving device, a driving method thereof, and a device equipped with the electromagnetic actuator.

In order to achieve the above object, an electromagnetic actuator device according to an aspect of the present invention includes an electromagnetic actuator and a drive unit.
The electromagnetic actuator has a mover and a stator.
The mover has a plurality of magnetic pole pairs arranged circumferentially.
The stator includes a plurality of first electromagnets and a plurality of second electromagnets.
The plurality of first electromagnets are disposed along the outer periphery of the mover.
The plurality of second electromagnets are arranged at symmetrical positions with the first electromagnets with respect to the mover so as to correspond to the plurality of first electromagnets, respectively.
The drive unit has the same angle as the first electromagnet and the predetermined angular position arranged at a predetermined angular position on the circumference among the plurality of first electromagnets and the plurality of second electromagnets. The electromagnetic actuator is driven so as to rotate the movable element by a predetermined angle along the circumference by exciting the second electromagnet arranged at a position in the same polarity direction. The drive unit excites the first and second electromagnets arranged at the predetermined positions with different current values while maintaining the polarities of the excited first and second electromagnets. Thus, the electromagnetic actuator is driven so that the mover is tilted.

  The drive unit rotates the mover along the circumference by exciting the corresponding first electromagnet and second electromagnet. Further, the drive unit makes them different from each other while maintaining the polarities of the excited first and second electromagnets after rotating the mover or immediately before the mover finishes rotating. The mover is tilted by exciting with the current value. That is, since the mover is driven to tilt while being positioned along the circumferential direction, the mover can be driven with high accuracy in at least two degrees of freedom.

  For example, the mover may have two magnetic pole pairs. In that case, the plurality of first electromagnets have three electromagnets respectively driven by a three-phase driving current, and the first electromagnets driven by the in-phase driving current follow the outer periphery of the mover. Two sets of the three electromagnets are provided so as to be spaced apart by 180 °. The plurality of second electromagnets include three electromagnets respectively driven by a three-phase driving current so as to correspond to the three electromagnets of the plurality of first electromagnets, and drive in the same phase Two sets of the three electromagnets are provided so that the second electromagnets driven by electric current are arranged 180 degrees apart along the outer periphery of the mover.

  In that case, the drive unit is configured to drive the first set of the plurality of first electromagnets and the plurality of second electromagnets with a drive current in phase with each other, 180 degrees apart along the outer periphery of the mover. The first and second electromagnets are excited and arranged so as to correspond to the same angular position on the circumference where the first and second electromagnets of the first set are arranged. Further, the mover may be rotated by the predetermined angle by exciting the first and second electromagnets of the second group with a drive current having the same phase as that of the first group. The drive unit excites the first and second electromagnets of the first set with a first current value, respectively, and the first and second electromagnets of the second set. May be excited at a second current value different from the first current value to incline the mover by a predetermined angle.

  High response is achieved by exciting the first and second electromagnets of the first group (or the second group), that is, the first and second electromagnets provided in the upper stage and the lower stage, respectively, facing each other. With this, you can tilt the mover without fail.

  Alternatively, the drive unit is 180 ° along an outer periphery of the mover, which is different from the first set and the second set among the plurality of first electromagnets and the plurality of second electromagnets. Exciting the first and second electromagnets of the separated third set with a first current value, respectively, and on the outer periphery of the mover different from the first, second and third sets The fourth set of first and second electromagnets separated by 180 ° along the second current value is excited with a second current value different from the first current value, thereby tilting the movable element by a predetermined angle. Also good.

The coils of the first and second electromagnets of the first set may be connected, and the coils of the first and second electromagnets of the second set may be connected.
In that case, the drive unit includes a first generator, a second generator, an inverter, a first adder, a second adder, a first driver, and a second driver. You may have.
The first generator generates a first drive signal having a first waveform pattern of the drive current for rotating the mover along the circumference.
The second generator generates a second drive signal having a second waveform pattern of the drive current for tilting the mover.
The inverter inverts the polarity of the emitted second drive signal.
The first adder adds the emitted first and second drive signals.
The second adder adds the emitted first drive signal and the inverted second drive signal.
The first driver drives the first electromagnet and the second electromagnet of the first set based on the signal added by the first adder.
The second driver drives the first electromagnet and the second electromagnet of the second set based on the signal added by the second adder.

  The current value of excitation when the drive unit rotates the mover along the circumference may be the same as one of current values different from each other when the mover is tilted, May be different. In the latter case, the drive unit can tilt the mover simply by setting one of the different current values to be different from the other, and the control becomes easy.

A driving apparatus according to an aspect of the present invention drives the above-described electromagnetic actuator, and includes a rotation command unit and a tilt command unit.
The rotation command means is the same as the first electromagnet and the predetermined angular position arranged at a predetermined angular position on the circumference among the plurality of first electromagnets and the plurality of second electromagnets. By exciting the second electromagnet arranged at the angular position in the same polarity direction, the mover is rotated by a predetermined angle along the circumference.
The tilt command means excites the first and second electromagnets arranged at the predetermined positions with different current values while maintaining the polarities of the excited first and second electromagnets. Tilt the mover with.

An electromagnetic actuator driving method according to an aspect of the present invention is the first electromagnet disposed at a predetermined angular position on the circumference among the plurality of first electromagnets and the plurality of second electromagnets. And the said 2nd electromagnet arrange | positioned in the same angular position as the said predetermined angular position is excited by the same polarity direction, and the said needle | mover is rotated a predetermined angle along the said circumference.
Further, the first and second electromagnets arranged at the predetermined positions are excited with different current values while maintaining the polarities of the excited first and second electromagnets. The child is tilted.

  An apparatus according to an aspect of the present invention is an apparatus equipped with the above-described electromagnetic actuator device. Examples of such a device include a robot device and an electronic device.

  According to the present invention, the electromagnetic actuator is driven with high accuracy with at least two degrees of freedom of rotation in the circumferential direction in which the magnetic poles of the mover are arranged and rotation (tilting) in at least one direction different from the rotation in the circumferential direction. can do.

It is a perspective view which shows the electromagnetic actuator which concerns on one Embodiment of this invention. It is a perspective view which shows the magnetization direction of the permanent magnet in the said electromagnetic actuator. (A) is a sectional view showing the driving principle when the mover is rotated around the x axis, and (B) is a sectional view showing the driving principle when the mover is rotated around the y axis. ) Is a plan view showing a driving principle when the mover is rotated around the z-axis. It is a figure which shows the structure of the drive unit of an electromagnetic actuator based on one Embodiment of this invention. It is a figure for demonstrating the arrangement | positioning relationship of a coil when a three-phase drive current is applied. It is a schematic diagram of the electromagnetic actuator for demonstrating rotation operation | movement of the needle | mover around az axis. It is a figure for demonstrating rotation (tilting) operation | movement of the needle | mover around an x-axis. It is a figure for demonstrating rotation (tilting) operation | movement of the needle | mover 1 around a y-axis. (A) is a top view which shows the electromagnetic actuator with which load was attached to the needle | mover in an initial state. It will be in the state shown in (B) is a top view which shows the electromagnetic actuator of the state shown to FIG. 6 (C) and (D). (C) is a top view which shows the electromagnetic actuator of the state shown to FIG.6 (E) and (F). (A) is sectional drawing which shows the electromagnetic actuator corresponding to FIG.9 (B). (B) And (C) is a figure which shows a mode that a needle | mover moves around an x-axis from the state shown to (A). (A) And (B) is a figure which shows a mode that a needle | mover moves around the x-axis and the y-axis from the state shown in FIG.9 (C), respectively.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration of electromagnetic actuator]
FIG. 1 is a perspective view showing an electromagnetic actuator according to an embodiment of the present invention. FIG. 1 illustrates the electromagnetic actuator 100 in an xyz space having an x axis, a y axis, and a z axis that are orthogonal to each other. The electromagnetic actuator 100 according to an embodiment of the present invention is configured as a kind of a spherical actuator that can rotate the mover about each of the x-axis, y-axis, and z-axis.

  As shown in FIG. 1, the electromagnetic actuator 100 includes a mover 1 and a stator 2. The mover 1 includes four permanent magnetic bodies 11 that are divided along the circumferential direction in the xy plane, and four permanent magnets inserted at equal pitches (90 ° intervals) between two adjacent magnetic bodies 11. And a magnet 12 (for example, Br = 1.4T). That is, the mover 1 has two magnetic pole pairs in the circumferential direction. The permanent magnet 12 is magnetized in the direction of the arrow d shown in FIG.

  The stator 2 has a plurality of electromagnets 3 for driving the mover 1. These electromagnets 3 include a core 32 and a coil 31 wound around the core 32. Six electromagnets 3 are provided in each of the upper and lower stages. The lower electromagnets 3 are arranged so as to correspond to each other so as to be symmetrical in the z-axis direction.

  Each core 32 is attached to the inner peripheral surface side of the outer frame portion 21 of the stator 2 having a circumferential shape so as to protrude toward the mover 1 at an equal pitch (60 ° interval). The tip surface of the magnetic pole 321 that is the end portion of the core 32 faces the outer peripheral surface of the mover 1. Opposing surfaces of the mover 1 and the stator 2 are each cut into spherical surfaces and supported so as to have a predetermined gap (for example, 0.5 mm).

  The current supplied to each coil 31 can be controlled independently, and the amount of excitation in each of the 12 magnetic poles 321 can also be controlled independently.

[Operation principle of electromagnetic actuator]
Hereinafter, the operation principle of the electromagnetic actuator 100 will be described.

  First, the principle of operation for rotational movement around the x-axis will be described. FIG. 3A shows a cross section perpendicular to the x-axis shown in FIG. Here, four magnetic poles 321 exist in the cross section A. Further, the magnetic body 11 facing these four magnetic poles 321 exhibits S-pole magnetism depending on the magnetization direction of the permanent magnet 12.

  Now, when the coil 31 is excited so that the magnetic pole shown in FIG. 3A appears, the mover 1 can obtain torque in the direction of the arrow in the figure. Further, when the current of the coil 31 is reversed, the mover 1 obtains torque in the direction opposite to that in FIG. The amount of torque in the rotation around the x axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32 existing in the cross section A.

  Next, the rotational movement around the y axis will be described with reference to FIG. FIG. 3B shows a cross section obtained by rotating the cross section A by 60 ° around the z axis, that is, the cross section B or the cross section C. Here, also in the cross section B and the cross section C, the four magnetic poles 321 exist in the cross section. Further, the magnetic body 11 facing the four magnetic poles 321 exhibits N-pole magnetism depending on the magnetization direction of the permanent magnet 12.

  Now, when the coil 31 is excited so that the magnetic pole shown in FIG. 3B appears, the mover 1 can obtain torque in the direction of the arrow in the figure. Further, when the current of the coil 31 is reversed, the mover 1 obtains torque in the direction opposite to that in FIG. That is, if the same magnitude of torque is applied to both the cross section B and the cross section C by the same action, the resultant force acting on the mover becomes a rotational torque around the y axis. The amount of torque in the rotation around the y axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32 existing in the cross section B or C.

  Finally, the operation principle of rotation around the z-axis will be described with reference to FIG. FIG. 3C shows a cross-sectional view perpendicular to the z-axis. Now, the coil 31 is excited so that the magnetic poles shown in FIG. 3C appear, that is, the coil 31 is excited so that the electromagnets 180 degrees apart in the direction around the z-axis are in phase, and the mover 1 Can obtain torque in the direction of the arrow in the figure. If the same magnetic pole is generated for each of the two stators arranged along the z axis, no torque is generated on the axes other than the z axis. Further, when the current of the coil 31 is reversed, the mover 1 obtains torque in the opposite direction. The amount of torque in the rotation around the z axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32.

[Configuration of electromagnetic actuator drive unit]
FIG. 4 is a diagram illustrating a configuration of a drive unit of the electromagnetic actuator 100 according to an embodiment of the present invention.

  The drive unit 5 includes a drive signal generation unit 51 that generates a waveform pattern of drive current around the x, y, and z axes, and a driver 52 that drives the coils 31 of the electromagnets 3 based on the drive current.

  The drive signal generator 51 includes an x pattern generator 51x, a y pattern generator 51y, and a z pattern generator 51z that generate waveform patterns of drive currents around the x, y, and z axes, respectively. The z pattern generator 51z generates a three-phase alternating current of U, V, and W. The x and y pattern generators 51x and 51y can generate both alternating current and direct current.

The drive unit 5 typically has six drivers 52, and two coils 31 are connected in series to one driver 52. These two coils 31 may be connected in parallel. Each driver 52 includes U ((U ₁₁ , U ₁₂ ), (U ₂₁ , U ₂₂ )), V ((V ₁₁ , V ₁₂ ), (V ₂₁ , V ₂₂ )), W ((W ₁₁ , W ₁₂ ) and (W ₂₁ , W ₂₂ )) are respectively connected to coils 31 excited by three-phase drive currents.

In the following description, for example, each coil 31 connected to the driver D1 is represented as a coil W ₁₁ and a coil W _12, and this one set of coils is represented as W ₁ (W ₁₁ , W ₁₂ ) and one set of coils ( W ₂₁ , W ₂₂ ) is represented as W ₂ (W ₂₁ , W ₂₂ ). For example, the coil 31 driven in the same phase of the W phase is represented as a coil W.

[Driving method according to one embodiment of electromagnetic actuator]
FIGS. 5A and 5B are diagrams for explaining the arrangement relationship of the coils 31 when a three-phase drive current is applied. FIG. 5B is a cross-sectional view taken along line V-V at the position of the coil V as an example in FIG.

The U, V, W phase coils 31 arranged on the upper side of the stator 2 are coils U ₁₁ , V ₁₁ , W ₁₁ , U ₂₁ , V ₂₁ , W ₂₁ . The coils 31 arranged on the lower side are U ₁₂ , V ₁₂ , W ₁₂ , U ₂₂ , V ₂₂ , W ₂₂ . With such an arrangement, the two coils 31 driven in the same phase, for example, the coils W ₁₁ and W ₂₁ are arranged at intervals of 180 °.

  One of the output currents 511x of the x pattern generator 51x is added to the W-phase output current 511z of the z pattern generator 51z by, for example, an adder 53a. The added current is input to the driver D1. The other 512x of the output current of the x pattern generator 51x is inverted by the inverter 54a and added to the output current 511z by the adder 53b. The added current is input to the driver D2.

  That is, in this embodiment, the output current of the x pattern generator 51x is superimposed on the current driven in the W phase from the z pattern generator 51z.

  Among the output currents of the y pattern generator 51y, the first output current 511y is added to the U-phase output current 512z of the z pattern generator 51z by, for example, the adder 53c, and the z pattern is generated by the adder 53e. It is added to the V-phase output current 513z of the device 51z. The added currents are input to the drivers D3 and D5, respectively.

  The second output current 512y of the y pattern generator 51y is inverted by the inverter 54b, and the inverted current is added to the U-phase output current 512z by the adder 53d. The added current is input to the driver D4. The second output current 512y is added to the V-phase output current 513z by the adder 53f, and the added current is input to the driver D6.

  That is, in this embodiment, the output current of the y pattern generator 51y is superimposed on the current driven in the U and V phases from the z pattern generator 51z.

  Each driver 52 executes various operations in accordance with an application program of a device to which the electromagnetic actuator 100 is applied. For example, these drivers 52 hold the drive current from the drive signal generation unit 51 at a predetermined value, change the amplitude of the drive current, or apply a DC or AC bias current to the current from the drive signal generation unit 51. Or add to.

  In addition, for example, when the drive signal generation unit 51 continuously maintains the state where the drive current of each pattern is generated, the driver 52 may switch ON / OFF of the drive current from the drive signal generation unit 51. . Alternatively, the ON / OFF switching may be performed by the drive signal generation unit 51.

  Each driver 52 is typically connected in parallel to a power source (not shown).

  Next, a driving method according to an embodiment of the electromagnetic actuator 100 will be described.

  FIG. 6 is a schematic diagram of the electromagnetic actuator 100 for explaining the rotation operation of the mover 1 around the z-axis.

  Basically, in driving around the z-axis, the electromagnetic actuator 100 is driven by the three-phase driving currents of the equations (1) to (3).

U = asin (θ + 120) (1)
V = asin (θ + 240) (2)
W = asinθ (3)

  For convenience of explanation, as shown in FIGS. 6A and 6B, when the electrical angle θ = 0 °, the mechanical angle becomes 0 ° (the rotation angle of the mover 1), and this state is defined as an initial state. FIG. 6B is a cross-sectional view taken along the line W-W in FIG. FIG. 9A is a plan view showing the electromagnetic actuator 100 in which the load 6 is attached to the mover 1 in this initial state. In addition, this load 6 shows a part of hand (end effector) of an articulated arm type | mold conveyance robot, for example.

In the initial state shown in FIGS. 6 (A) and 6 (B), the distribution of the current value is represented by equation (4) (see FIG. 6 (A)) from equations (1) to (3). In this initial state, the coil W is not excited, that is, the driving current is 0, and the coils U and V are excited with the same driving current. That is, the currents flowing through the coils U ((U ₁₁ , U ₁₂ ), (U ₂₁ , U ₂₂ )) all have the same magnitude, and the coils V ((V ₁₁ , V ₁₂ ), (V ₂₁ , V ₂₂ )). ) All of the current flowing through it will have the same magnitude.

  When the electrical angle θ = 90 ° from the initial state, the mechanical angle is 45 °, the current value distribution is expressed by equation (5), and the electromagnetic actuator 100 is in the state shown in FIGS. 6C and 6D. FIG. 6D is a cross-sectional view taken along the line W-W in FIG. FIG. 9B is a plan view showing the electromagnetic actuator 100 at this time. The drivers D1 and D2 hold the current value to the coil W, so that the mover 1 is stabilized at this position. In the present embodiment, since the number of magnetic pole pairs of the mover 1 is 2, when the electrical angle θ = 90 °, the mechanical angle is 45 °. The electromagnetic actuator 100 can tilt the mover 1 around the x axis, for example, by driving the drivers D3 to D6 from the state shown in FIGS. 6C and 6D.

  As shown in FIGS. 6E and 6F, when the electrical angle θ = 270 ° from the initial state, the mechanical angle is 135 °, and the distribution of the current value is expressed by equation (6). FIG. 9C is a plan view showing the electromagnetic actuator 100 at this time. In this case, when viewed from the state shown in FIGS. 6C and 6D, the electrical angle advances by 180 °, that is, reverses, and the mechanical angle advances by 90 °. The drivers D1 and D2 hold the current value to the coil W, so that the mover 1 is stabilized at this position. From the state shown in FIGS. 6E and 6F, the electromagnetic actuator 100 can tilt the mover 1 around the y axis, for example, by driving the drivers D3 to D6.

  FIG. 7 is a view for explaining the rotation (tilting) operation of the mover 1 around the x-axis.

  7A and 7B show the same state as FIGS. 6C and 6D. From the state shown in FIGS. 7A and 7B (the state of θ = 90 °), a direct current is applied to, for example, the coil W by generating the drive current by the x pattern generator 51x and driving the drivers D1 and D2. A bias current b is applied. The three-phase drive current at this time can be expressed by the following equations (7) to (9).

U = asin (90 ° + 120 °) (7)
V = asin (90 ° + 240 °) (8)
W = asin90 ° ± b (9)

The bias current + b is an output current 511x from the x pattern generator 51x, and this output current 511x is added to the W-phase drive current, and the driver D1 sets a set of coils W ₁ ( W ₁₁ and W ₁₂ ) are excited.

The bias current -b is obtained by inverting the output current 512x from the x pattern generator 51x. The inverted current is added to the W-phase drive current, and the driver D1 outputs 1 based on the addition signal. The pair of coils W ₂ (W ₂₁ , W ₂₂ ) is excited.

By such excitation of the coil W, the current flowing through the coils W ₁ (W ₁₁ , W ₁₂ ) increases from the state shown in FIGS. 7A and 7B, and the coils W ₂ (W ₂₁ , W ₂₂ ) are increased. The current that flows through is reduced. Thereby, as shown in FIGS. 7C and 7D, the drive unit 5 fixes the position of the mover 1 around the z axis, that is, the coils W ((W ₁₁ , W ₁₂ ), ( The movable element 1 can be tilted around the x-axis while maintaining the polarities of the four electromagnets 3 according to W ₂₁ , W ₂₂ )). In this case, the value of b is set in advance so that the polarity of the drive current of the coil W ((W ₁₁ , W ₁₂ ), (W ₂₁ , W ₂₂ )) does not change.

  FIG. 10A is a cross-sectional view showing an electromagnetic actuator corresponding to FIG. FIGS. 10B and 10C are views showing a state in which the mover 1 moves around the x axis from the state shown in FIG.

  Here, instead of the formula (9), the following formula (9 ′) may be used.

    W = asin θ ± bsin (2πft) (9 ′).

In the equation (9 ′), the x pattern generator 51x generates an alternating current (frequency f) as a bias current. In this case, the polarity of one set of coils W ₁ (W ₁₁ , W ₁₂ ) and the polarity of another set of coils W ₂ (W ₂₁ , W ₂₂ ) are periodically switched, and the mover 1 has an inclination angle Is in a rocking state in which is periodically reversed.

  FIG. 8 is a view for explaining the rotation (tilting) operation of the mover 1 around the y-axis. FIGS. 8A and 8B show the same state as FIGS. 6E and 6F, and show a cross section at the position of the coil V, for example. From the state shown in FIGS. 8A and 8B (the state of θ = 270 °), the drive current is generated by the y pattern generator 51y and the drivers D3 and D6 are driven, for example, to the coils U and V. A bias current b which is a direct current is applied. The three-phase drive current at this time can be expressed by the following equations (7) to (9).

U = asin (270 ° + 120 °) ± b (10)
V = asin (270 ° + 240 °) ± b (11)
W = asin270 ° (12)

The bias current + b is the first and second output currents 511y and 512y from the y pattern generator 51y, and these output currents 511y and 512y are the U-phase and V-phase drive currents from the z pattern generator 51z. Are added to each other. The drivers D3 and D5 excite the set of coils U ₁ (U ₁₁ , U ₁₂ ) and the set of coils V ₁ (V ₁₁ , V ₁₂ ) based on the added signals.

The bias current −b is obtained by inverting the second output current 512y from the y pattern generator 51y, and these inverted output currents are the U-phase and V-phase drive currents from the z pattern generator 51z. Each is added. The drivers D4 and D6 excite the set of coils U ₂ (U ₂₁ , U ₂₂ ) and the set of coils V ₂ (V ₂₁ , V ₂₂ ) based on the added signals.

By exciting the coils U and W, for example, the coils U ₂ (U ₂₁ , U ₂₂ ) and the coil V ₂ (V ₂₁ , V ₂₂ ) are changed from the state shown in FIGS. The flowing current increases, and the current flowing through the coil U ₁ (U ₁₁ , U ₁₂ ) and the coil V ₁ (V ₁₁ , V ₁₂ ) decreases. As a result, as shown in FIGS. 8C and 8D, the drive unit 5 fixes the position of the mover 1 around the z axis, that is, the coils W ((W ₁₁ , W ₁₂ ), ( The movable element 1 can be tilted around the y-axis while maintaining the polarities of the four electromagnets 3 according to W ₂₁ and W ₂₂ )). In this case, the value of b is set in advance so that the polarity of the drive current of the coils U and V does not change.

  11 (A) and 11 (B) are views showing how the mover 1 moves around the x axis and around the y axis from the state shown in FIG. 9 (C), respectively.

  Here, instead of the equations (10) and (11), the following equations (10 ') and (11') may be used.

U = asin (270 ° + 120 °) ± bsin (2πft) (10 ')
V = asin (270 ° + 240 °) ± bsin (2πft) (11 ')

In the expressions (10 ′) and (11 ′), the y pattern generator 51y generates an alternating current (frequency f) as a bias current. In this case, the polarities of the coil U ₁ (U ₁₁ , U ₁₂ ) and the coil V ₁ (V ₁₁ , V ₁₂ ) and the coil U ₂ (U ₂₁ , U ₂₂ ) and the coil V ₂ (V ₂₁ , V ₂₂ ) The polarity is periodically switched, and the mover 1 is in a swinging state in which the tilt angle is periodically reversed.

As described above, in the present embodiment, the drive unit 5 maintains the polarity of the electromagnet of the excited coil W after rotating the mover 1 around the z-axis or immediately before completing the rotation. The mover 1 is tilted by exciting them with different current values. Alternatively, the drive unit 5 rotates the mover 1 about the z axis or immediately before the rotation is completed, while maintaining the polarity of the electromagnet of the excited coil W (U ₁ , V ₁ ). And the mover 1 is tilted by exciting the coils (U ₂ , V ₂ ) with different current values. That is, since the mover 1 is driven to tilt while being positioned along the circumferential direction, the mover 1 can be driven with high accuracy with at least two degrees of freedom.

  Further, in this embodiment, since the rotation angle of the mover 1 is determined around the z axis, it is not necessary to detect the rotation angle of the mover 1 around the z axis, and control in an open loop becomes possible. .

Further, in this embodiment, as shown in FIG. 7D, a set of coils W ₁ (W ₁₁ , W ₁₂ ) (or a set of coils) provided at the upper stage and the lower stage, respectively, separated by 180 °. Since W ₂ (W ₂₁ , W ₂₂ )) is excited, the mover 1 can be reliably tilted with high response. The same applies to the coils U and V shown in FIG.

  The electromagnetic actuator 100 described above can be mounted on various devices. For example, there are industrial robots, other robots, and electronic devices. As an industrial robot, for example, a transfer device that transfers a semiconductor wafer, a glass substrate for display, or the like, for example, an articulated arm type transfer robot, can be cited as an example. For example, when the electromagnetic actuator 100 is mounted on a camera as an electronic device, the electromagnetic actuator 100 is used as an actuator that drives a light receiving optical system of the camera.

[Other embodiments]
The embodiment according to the present invention is not limited to the above-described embodiment, and various other embodiments are conceivable.

  The drive unit 5 is not limited to the configuration shown in FIG. For example, the number of drivers 52 may not be six, and for example, twelve drivers may drive twelve coils 31 respectively. Also in this case, the circuit configuration of the previous stage of the 12 drivers may be the same as that of the drive unit 5.

Alternatively, even if the inverter 54a or 54b is not provided, the driver 52 can tilt (or swing) the mover 1 around the x and / or y axes by controlling the amplitude of the drive current and the like. . As an example, for example, after the mover 1 rotates around the z axis, the current value of one set of W ₁ (W ₁₁ , W ₁₂ ) is maintained as it is, with the polarity of the coil W maintained, for example. The set of coils W ₂ (W ₂₁ , W ₂₂ ) may be driven with a different current value. The same applies to the coils U and V.

In the above embodiment, the two coils 31 connected to one driver 52 are connected in series, but may be connected in parallel.
In formulas (7) to (9), (9 ′), (10) to (12), (10 ′) and (11 ′), a stepped wave, a triangular wave, a trapezoidal wave, etc. are not necessarily sin waves. It may be.

  The electromagnetic actuator 100 is not limited to the structural example described above. For example, in the electromagnetic actuator 100 shown in FIG. 1, the number of divisions of the magnetic body and permanent magnet in the mover is 4, and the number of magnetic poles in the stator is 12 (6 for each of the 2 stators). However, in principle, the electromagnetic actuator 100 can be realized by the same operation principle even when the number of divisions of the magnetic body and permanent magnet in the mover is 4N and the number of magnetic poles in the stator is 12N. be able to.

DESCRIPTION OF SYMBOLS 1 ... Movable element 2 ... Stator 3 ... Electromagnet 5 ... Drive unit 31 ... Coil 32 ... Core (magnetic pole 321)
51x ... x pattern generator 51y ... y pattern generator 51z ... z pattern generator 52 ... drivers 53a to 53f ... adders 54a, 54b ... inverter 54b ... inverter 100 ... electromagnetic actuator

Claims (9)

A stator having a plurality of magnetic pole pairs arranged circumferentially, a plurality of first electromagnets and a plurality of second electromagnets, and a plurality of stators arranged along the outer periphery of the mover The first electromagnet and a plurality of second electromagnets arranged in symmetrical positions with the first electromagnet with respect to the mover so as to correspond to the plurality of first electromagnets, respectively. An electromagnetic actuator having a stator;
Among the plurality of first electromagnets and the plurality of second electromagnets, the first electromagnet arranged at a predetermined angular position on the circumference and the same angular position as the predetermined angular position. Exciting the second electromagnet in the same polarity direction to rotate the mover by a predetermined angle along the circumference and maintaining the polarities of the excited first and second electromagnets An electromagnetic actuator device comprising: a drive unit that drives the electromagnetic actuator so that the movable element is tilted by exciting the first and second electromagnets arranged at the predetermined positions with different current values. The electromagnetic actuator device according to claim 1,
The mover has two magnetic pole pairs,
The plurality of first electromagnets have three electromagnets driven by three-phase drive currents, respectively, and the first electromagnets driven by the same-phase drive currents are 180 ° along the outer periphery of the mover. Two sets of each of the three electromagnets are provided so as to be spaced apart from each other,
The plurality of second electromagnets have three electromagnets respectively driven by a three-phase drive current so as to correspond to the three electromagnets of the plurality of first electromagnets, respectively. An electromagnetic actuator device in which two sets of the three electromagnets are provided so that the driven second electromagnets are arranged 180 degrees apart along the outer periphery of the mover. The electromagnetic actuator device according to claim 2,
The drive unit is
Among the plurality of first electromagnets and the plurality of second electromagnets, a first set of first and second electromagnets having a drive current in phase with each other and 180 degrees apart along the outer periphery of the mover. A first of the second set that is excited and is arranged to correspond to the same angular position on the circumference where the first and second electromagnets of the first set are arranged. And the second electromagnet is excited by a drive current having the same phase as the first set, thereby rotating the movable element by the predetermined angle,
The first and second electromagnets of the first set are respectively excited with a first current value, and the first and second electromagnets of the second set are excited with the first current. An electromagnetic actuator device that inclines the movable element by a predetermined angle by exciting each with a second current value different from the value. The electromagnetic actuator device according to claim 2,
The drive unit is
Among the plurality of first electromagnets and the plurality of second electromagnets, a first set of first and second electromagnets having a drive current in phase with each other and 180 degrees apart along the outer periphery of the mover. A first of the second set that is excited and is arranged to correspond to the same angular position on the circumference where the first and second electromagnets of the first set are arranged. And the second electromagnet is excited by a drive current having the same phase as the first set, thereby rotating the movable element by the predetermined angle,
Of the plurality of first electromagnets and the plurality of second electromagnets, the third set is different from the first set and the second set and is separated by 180 ° along the outer periphery of the mover. The first and second electromagnets are respectively excited with a first current value, and are different from the first, second and third groups, and are 180 ° apart from each other along the outer periphery of the mover. An electromagnetic actuator device that inclines the movable element by a predetermined angle by exciting each of the first and second electromagnets of four groups with a second current value different from the first current value. The electromagnetic actuator device according to claim 3 or 4,
The coils of the first and second electromagnets of the first set are connected, and the coils of the first and second electromagnets of the second set are connected,
The drive unit is
A first drive signal having a first waveform pattern of the drive current for rotating the mover along the circumference, and a second waveform of the drive current for tilting the mover A generator for generating a second drive signal in a pattern;
An inverter that inverts the polarity of the emitted second drive signal; and a first adder that adds the emitted first and second drive signals;
A second adder for adding the emitted first drive signal and the inverted second drive signal;
A first driver for driving the first and second electromagnets of the first set based on the signal added by the first adder;
An electromagnetic actuator device comprising: a second driver that drives the first and second electromagnets of the second set based on a signal added by the second adder. The electromagnetic actuator device according to any one of claims 1 to 5,
The drive unit is configured such that a current value for the excitation when the mover is rotated along the circumference is one of the different current values for the excitation when the mover is tilted. Electromagnetic actuator device set to be the same as one. A stator having a plurality of magnetic pole pairs arranged circumferentially, a plurality of first electromagnets and a plurality of second electromagnets, and a plurality of stators arranged along the outer periphery of the mover The first electromagnet and a plurality of second electromagnets arranged in symmetrical positions with the first electromagnet with respect to the mover so as to correspond to the plurality of first electromagnets, respectively. A drive device for an electromagnetic actuator having a stator,
Among the plurality of first electromagnets and the plurality of second electromagnets, the first electromagnet arranged at a predetermined angular position on the circumference and the same angular position as the predetermined angular position. Rotation command means for rotating the mover by a predetermined angle along the circumference by exciting the second electromagnet in the same polarity direction;
The movable element is tilted by exciting the first and second electromagnets arranged at the predetermined positions with different current values while maintaining the polarity of the excited first and second electromagnets. A drive device for an electromagnetic actuator comprising tilt command means. A stator having a plurality of magnetic pole pairs arranged circumferentially, a plurality of first electromagnets and a plurality of second electromagnets, and a plurality of stators arranged along the outer periphery of the mover The first electromagnet and a plurality of second electromagnets arranged in symmetrical positions with the first electromagnet with respect to the mover so as to correspond to the plurality of first electromagnets, respectively. A method for driving an electromagnetic actuator having a stator,
Among the plurality of first electromagnets and the plurality of second electromagnets, the first electromagnet arranged at a predetermined angular position on the circumference and the same angular position as the predetermined angular position. By exciting the second electromagnet in the same polarity direction, the movable element is rotated by a predetermined angle along the circumference,
The movable element is tilted by exciting the first and second electromagnets arranged at the predetermined positions with different current values while maintaining the polarity of the excited first and second electromagnets. Driving method of electromagnetic actuator. A stator having a plurality of magnetic pole pairs arranged circumferentially, a plurality of first electromagnets and a plurality of second electromagnets, and a plurality of stators arranged along the outer periphery of the mover The first electromagnet and a plurality of second electromagnets arranged in symmetrical positions with the first electromagnet with respect to the mover so as to correspond to the plurality of first electromagnets, respectively. An electromagnetic actuator having a stator;
Among the plurality of first electromagnets and the plurality of second electromagnets, the first electromagnet arranged at a predetermined angular position on the circumference and the same angular position as the predetermined angular position. Exciting the second electromagnet in the same polarity direction to rotate the mover by a predetermined angle along the circumference and maintaining the polarities of the excited first and second electromagnets An electromagnetic actuator device comprising: a drive unit that drives the electromagnetic actuator so that the movable element is tilted by exciting the first and second electromagnets arranged at the predetermined positions with different current values. Installed device.