Multi-axis positioner
11681100 · 2023-06-20
Assignee
Inventors
Cpc classification
G02B6/2555
PHYSICS
F16M11/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G02B6/3616
PHYSICS
F16M11/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16M11/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16M11/041
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
G02B6/25
PHYSICS
F16M11/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16M11/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16M11/18
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16M11/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A multi-axis positioning stage or positioner includes a top plate supported and manipulatable by a plurality of prismatic joint actuators. Each actuator includes an actuator joint having four or five Degrees of Freedom (DOF) with the top plate. When one or more of the actuators extends or contracts, the pivot points, or four or five DOF actuator joints, of the remaining actuators are allowed to shift to move the top plate. The actuators can be disposed between at least one base plate or base structure, and can be fixed thereto.
Claims
1. A positioner, comprising: a structure; at least one base; a plurality of actuators configured to support the structure over the at least one base and to move the structure relative to the at least one base in response to extension or retraction of one or more actuators, wherein: three or more of the actuators maintains contact with the structure through a joint having at least four degrees of freedom (DOF).
2. The positioner of claim 1, wherein the three or more actuators includes at least two actuators that maintain contact with the structure through a joint having five DOF.
3. The positioner of claim 2, wherein the three or more actuators includes at least two actuators that maintain contact with the structure through a joint having four DOF.
4. The positioner of claim 1, wherein the three or more actuators includes at least two actuators that maintain contact with the structure through a joint having four DOF.
5. The positioner of claim 1, wherein at least one joint having four DOF is a magnetic joint.
6. The positioner of claim 1, wherein at least one joint having five DOF is a magnetic joint.
7. The positioner of claim 1, wherein each of the three or more actuators has a magnetic joint with the structure.
8. The positioner of claim 1, wherein an actuator having a 4 DOF joint with the structure has a cylindrical end that contacts the structure.
9. The positioner of claim 1, wherein an actuator having a 5 DOF joint with the structure has a hemispherical end that contacts the structure.
10. The positioner of claim 1, wherein the structure includes a lengthwise groove, depression, or channel.
11. The positioner of claim 10, wherein the lengthwise groove, depression, or channel is configured to hold at least one optical fiber.
12. The positioner of claim 10, wherein the structure includes a V-groove configured to hold at least one optical fiber.
13. The positioner of claim 1, wherein: the structure comprises a top plate and the at least one base includes at least one base plate, and the three or more actuators that support the top plate are coupled to the at least one base plate.
14. The positioner of claim 13, wherein the top plate includes angled sides engaged by the three or more actuators and the at least one base plate includes angle side pieces to which the three or more actuators is coupled and the angled sides of the top plate and the angled side pieces of the at least one base plate have the same angle with respect to a vertical plane or axis.
15. The positioner of claim 1, further comprising an end plate including a coupling to an end of the structure.
16. The positioner of claim 15, wherein the coupling is a magnetic coupling.
17. A positioner, comprising: a top plate; a baseplate; and three or more actuators configured to support the top plate over the baseplate and to move the top plate in response to extension or retraction of one or more actuators, wherein each of the actuators maintains contact with the top plate through a joint having at least four degrees of freedom (DOF).
18. The positioner of claim 17, wherein the three or more actuators includes at least two actuators that maintain contact with the top plate through a joint having four DOF and at least one actuator that maintains contact with the top plate though a joint having five DOF.
19. The positioner of claim 17, wherein the top plate includes angled sides engaged by the three or more actuators and the base plate includes angle side pieces to which the three or more actuators are coupled and the angled sides of the top plate and the angled side pieces of the base plate have the same angle with respect to a vertical plane or axis.
20. The positioner of claim 17, wherein the actuators having a 4 DOF joint with the top plate have a cylindrical end.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention will become more apparent in view of the attached drawings and accompanying detailed description. The embodiments depicted therein are provided by way of example, not by way of limitation, wherein like reference numerals refer to the same or similar elements. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating aspects of the invention. In the drawings:
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(30) Various aspects of the inventive concepts will be described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments are shown. The present inventive concept may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.
(31) It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another, but not to imply a required sequence of elements. For example, a first element can be termed a second element, and, similarly, a second element can be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. The term “or” is not used in an exclusive or sense, but in an inclusive or sense.
(32) It will be understood that when an element is referred to as being “on” or “connected” or “coupled” to another element, it can be directly on or connected or coupled to the other element or intervening elements can be present. In contrast, when an element is referred to as being “directly on” or “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).
(33) The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.
(34) Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like may be used to describe an element and/or feature's relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and/or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” and/or “beneath” other elements or features would then be oriented “above” the other elements or features. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
(35) Exemplary embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized exemplary embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.
(36) To the extent that functional features, operations, and/or steps are described herein, or otherwise understood to be included within various embodiments of the inventive concept, such functional features, operations, and/or steps can be embodied in functional blocks, units, modules, operations and/or methods. And to the extent that such functional blocks, units, modules, operations and/or methods include computer program code, such computer program code can be stored in a computer readable medium, e.g., such as non-transitory memory and media, that is executable by at least one computer processor.
(37) In example embodiments in accordance with principles of inventive concepts, a multi-axis positioner or positioning stage includes a support plate supported by a plurality of actuators, such as one or more prismatic joint actuators. In preferred embodiments, one or more of the actuators includes an actuator joint having five Degrees of Freedom (DOF) with respect to the support plate. In various embodiments, one or more actuators includes an actuator joint having four DOF with respect to the support plate. In operation, when one or more of the actuators extends or contracts, the pivot points of the 5 DOF actuators are allowed to shift in any axis other than that actuator's axis of motion (that is, an axis defined by the actuator's extension and contraction).
(38) In various embodiments, the support plate can include a top surface supporting an object and a bottom surface engaged by movable ends of at least some of the actuators. One or more of the actuators can be disposed between the top plate and one or more structures. In some embodiments, at least some of the actuators can have a first end that is secured or coupled to a base plate or base structure and a second end that engages and moves the support (or top) plate.
(39) In example embodiments, magnetic force, gravity, and/or a pliable polymer, such as silicone, may be employed to keep the five DOF pivot points in contact with their respective (that is, top or bottom) plate when the prismatic actuators are retracted.
(40) In some example embodiments, at least two of the prismatic actuators can be perpendicular to at least two other prismatic actuators.
(41) In some embodiments, a fifth axis of movement can be included. If a fifth axis is included, its associated prismatic actuator can be arranged perpendicular to the other four prismatic actuators, in some embodiments.
(42) In example embodiments, the actuators may be any of several types, such as: piezo actuators, manual micrometer screws, magnetic actuators, stepper motors with linear actuators (either integral or separate), hydraulic cylinders, pneumatic cylinders, or rotary motors with eccentric cams, for example. In example embodiments in accordance with principles of inventive concepts, the position is configured such that the push and pull forces exerted by each actuator is greater than the shear friction of all the other actuators combined. In example embodiments, this can be accomplished by employing materials that have a high holding force but a low shear force, for example, such as a hard, metal actuator end, e.g., having a spherical, flat, or point surface, magnetically coupled to and held in contact with a hard, flat metal surface of the support plate. In such embodiments only one of the contact surfaces (that is, either the hard, metal actuator end surface or the hard, flat metal surface) is magnetized, because if both sides are magnetic they will be semi-constrained in the sliding axis and, therefore, behave like a spherical 3DOF joint.
(43) In example embodiments in accordance with principles of inventive concepts, a positioning stage includes a plurality of prismatic joint actuators, a base plate (or structure) and a top plate. The top plate may support a device for precise positioning thereof, and is a support plate. The top plate may be supported by a plurality of prismatic actuators, which are, in turn, supported by the base plate or other structure. In example embodiments, one or more actuators is fixed to a portion of the baseplate, which positions each actuator at an angle relative to a vertical axis or plane. In example embodiments, sides of the top plate are formed at the same angle to the vertical axis or plane as sides of the baseplate, although other configurations are contemplated within the scope of inventive concepts. For instance, the vertical plane can be a plane running vertically the length of the center of the top plate and base plate. In various embodiments, one or more sides of the top plate can be parallel to one or more sides of the base plate in at least one position of the top plate, e.g., when the actuators have equal lengths.
(44) In various embodiments, a magnetic field can be established between the supporting actuator ends and the sides of the top plate, such that, for at least one actuator, a magnetic joint is formed between a portion of the top plate surface and the actuator end. In various embodiments, either the actuator end or the angled sides of the top plate includes or is formed of a magnetic field generating material, e.g., a magnet, and the other includes or is made from magnetic material, e.g., a ferrous metal. In example embodiments, if an end of an actuator can be in the shape of a hemisphere, but other shapes and combinations, such as cylinders, are contemplated within the scope of inventive concepts. In various embodiments, the actuator ends include or are formed from a magnetic material and each magnetic material end is configured to contact a magnet or magnetic surface on a side of the top plate to thereby movably support the top plate above the baseplate.
(45) In some embodiments, the magnet on the side of the top plate conforms to an outer surface of the top plate. An inner surface of the top plate need not be or include a magnet. In some embodiments, the top plate can have a cross section with a planar shape, a V-shape, a semi-cylindrical shape, or another shape.
(46) In operation, in a preferred embodiment, an actuator distal end is maintained in contact with a magnet on an outer surface or side of the top plate through force of the magnet. As an actuator is activated, e.g., extended or retracted, the top plate moves responsively in the direction of motion determined by the motion of the actuator. Therefore, the actuator can be extendible and retractable along an axis. The distal end of an actuator in contact with a magnet on an opposite side of the top plate remains in contact with the magnet, through the magnetic force of the magnet operating upon the magnetic material of the actuator's distal end. At the same time, the distal end of such actuator allows the magnet (and top plate) to slide in a direction dictated by the motion of the activated actuator. With respect to activation, this opposite side actuator can be passive, i.e., not activated, or activated in a different direction and/or to different extents, in various embodiments.
(47) A multi-axis positioner or positioning stage in accordance with principles of inventive concepts can take the form of a parallel positioner. As a parallel position, the apparatus does not suffer from the mechanical stack up issues associated with multiple single axis stages stacked on top of each other in what may be referred to as a kinematic chain. Additionally, unlike a hexapod, a positioning stage in accordance with principles of inventive concepts allows for any combination of the four actuators to extend or contract any amount at any speed without the stage binding. Each actuator can be arranged to affect movement in two different axes of the top plate of the stage. To implement a single axis of motion, two actuators may be moved in a manner in which they complement one another in the desired axis and cancel each other in an undesired axis. As a result, in example embodiments in accordance with principles of inventive concepts, single-axis stage moves can employ dual actuator moves. Single-axis stage moves, and the associated actuator actions, are shown in the tables of
(48) In addition to being a parallel actuator, a positioning stage in accordance with principles of inventive concepts can have several other benefits. For example, a positioning stage in accordance with principles of inventive concepts is scalable from four to six axes, incrementally, whereas a Stewart Platform always has three or six axes. Unlike a kinematic chain, a positioning stage in accordance with principles of inventive concepts does not exhibit tolerance stack up of individual stages. A positioning stage in accordance with principles of inventive concepts does not require rotary or linear bearings, whereas a kinematic chain requires one for each axis of freedom. With a positioning stage in accordance with principles of inventive concepts, each axis of motion only requires two actuators that move at a fixed, intuitive ratio and, therefore, desired motion is relatively easy to achieve. As previously indicated, this is not the case with a Stewart Platform. Additionally, unlike a Stewart Platform, the speed of actuation need not be controlled to prevent stage binding and individual actuators can be moved without binding the stage. In example embodiments, the positioning stage top plate may be readily removed and replaced simply by decoupling the interfaces, such as magnetic interfaces between the actuators and the top plate.
(49) In example embodiments, the resolution and stiffness of the positioning stage may be dependent on the quality of the actuators, the smoothness of the slider components, whether hemispherical, cylindrical, or otherwise, and the strength of the magnetic (or other) force holding the joints formed between the actuators and the top plate together. All of these aspects can be optimized to create a submicron precision positioning stage for a small fraction of the cost of a similar precision hexapod. In many cases, a positioning stage in accordance with principles of inventive concepts will outperform a standard kinematic chain while, at the same time, being more cost-effective. In example embodiments, the holding force (for example, magnetic holding force) of an actuator slider (or other four of five DOF connection) is greater than the coefficient of friction of all of the other actuator joints. When this is true, the top plate will settle at an equilibrium that allows the four (or more) connections to slide or pivot as needed to ensure that all of the points of contact are maintained.
(50) A four axis positioning stage with a constrained Z axis in which other degrees of freedom are not interfered with may be implemented in accordance with principles of inventive concepts by using a rigid beam to constrain or restrict such Z axis movement, or by replacing one of the four five-DOF actuator joints with a four-DOF joint, restricting motion in the Z axis, as illustrated in
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(53) With respect to
(54) In example embodiments, baseplate 102 includes angled side pieces 118, 120. In this embodiment, θ.sub.1 and θ.sub.2 respectively represent angles of interior surfaces of the side pieces 118 and 120 relative to a vertical axis and/or plane. The angled side pieces of the base plate may also be formed at an angle θ with respect to a horizontal plane, here θ=θ.sub.1=θ.sub.2 in this embodiment. In other embodiments, it may be possible for θ≠θ.sub.1, θ≠θ.sub.2 and/or θ.sub.1≠θ.sub.2. In other embodiments, θ may be irrelevant, and θ.sub.1=θ.sub.2 can still hold true. In this embodiment, exterior sides 122, 124 of top plate 104 are formed at the same angles θ.sub.1, θ.sub.2 relative to the vertical axis and/or plane. Therefore, the inner surface of the side piece 118 of the base plate 102 can be parallel to exterior side 122 of the top plate 104 and the inner surface of the side piece 120 of the base plate 102 can be parallel to exterior side 124 of the top plate 104. The vertical plane can be a plane running vertically the length of the center of the top plate 104 and base plate 102.
(55) In the embodiment of
(56) In this embodiment, each of the actuators 106, 108, 110, and 112 extends from one of the side pieces 118, 120 of the base plate 102, in a direction toward the top plate 104. For example, in this embodiment, each actuator is secured or coupled to a side piece of the base plate 102 and extends at an angle of 90 degrees with respect to the corresponding side piece 118 or 120 toward the corresponding side 122 or 124 of the top plate 104.
(57) A distal end of each actuator 106, 108, 110, and 112 includes a magnetic material. In this embodiment, each of the actuators 106, 108, 110, and 112 includes ferrous metal hemispheric ends 134, 136, 138 and 140. Magnets 126, 128, 130, and 132 are disposed on or in the sides 122, 124 of the top plate 104 in locations corresponding to the ferrous metal hemispheric ends 134, 136, 138, and 140 of respective actuators 106, 108, 110, and 112.
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(67) The table of
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(70) Magnets 135 and 135 are disposed on or in the sides 122, 124 of the top plate 104 in locations corresponding to the ferrous metal hemispheric ends 134, 136, 138, and 140 at distal ends of respective actuators 106, 108, 110, and 112.
(71) In example embodiments actuators 106, 108, 110, and 112 may be precision adjustment mechanisms, such as micrometer screws 106a, 108a, 110a, 112a, that allow single-digit micron precision adjustment.
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(75) Referring to
(76) In various embodiments, the system includes three or more actuators that maintain contact with the structure through a joint having four or five degrees of freedom (DOF). And, optionally, the system can contain no actuators that maintain contact with the structure through a joint having 3 or less DOF.
(77) In example embodiments, the positioner can also include at least one bottom plate (or structure) and the actuators can be disposed between the at least one bottom plate and the top plate, and fixed to the at least one bottom plate (or structure).
(78) In operation, when one or more of the actuators extends or contracts, pivot points at the interfaces of the remaining actuators with the support plate (e.g., the 4DOF and/or 5DOF joints) are allowed to shift in any of at least four axes, other than that actuator's axis of motion. As previously indicated, 4 DOF joints with the support plate may be formed by an actuator having an end comprising an edge slider or a cylindrical slider, as examples. In preferred embodiments, as with the 5 DOF joint embodiments discussed above, at least two of the prismatic actuators can be perpendicular to at least two other prismatic actuators and, if a fifth or sixth axis is added, their associated prismatic actuators may be arranged perpendicular to the other four prismatic actuators, in various embodiments.
(79) As with the 5 DOF embodiments discussed above, the ends of the actuators can be magnetically coupled to the support (or top) plate. In operation, when one or more of the actuators extends or contracts, the pivot points of the remaining actuators are allowed to shift and move with respect to the top plate, while remaining magnetically, movably coupled to the support (or top) plate.
(80) As above, in example embodiments, the actuators may be any of several types, such as: piezo actuators, manual micrometer screws, magnetic actuators, stepper motors with linear actuators (either integral or separate), hydraulic cylinders, pneumatic cylinders, or rotary motors with eccentric cams, for example. In example embodiments in accordance with principles of inventive concepts, the positioner is configured such that the push and pull forces exerted by each actuator is greater than the shear friction of all the other actuators combined. In example embodiments, this can be accomplished by employing materials that have a high holding force, but a relatively low shear force, for example, such as a hard metal end surface of the actuators magnetically held in contact with a hard, flat metal surface of the top plate.
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(82) The support plate can be configured to hold an object to be positioned. In some embodiments, the object can be at least one optical fiber. In some embodiments, the support plate can include a groove or channel configured to maintain the object in a preferred position. In some embodiments, the support plate can include a V-shaped groove configured to maintain the object in a preferred position. In some embodiments, the positioner or positioning stage can form part of a fiber processing machine, such as an optical fiber splicer, as an example, and the groove can be configured to hold or support at least one optical fiber.
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(84) With respect to
(85) In example embodiments, similar to the embodiments discussed above, the baseplate 302 includes side pieces 318, 320 having interior angled sides that are each formed at an angle with respect to a vertical axis or plane “A,” e.g., see θ.sub.1 and θ.sub.2 discussed above, which can apply to this embodiment. For instance, the vertical plane A can be a plane running vertically the length of the center of the top plate 304 and base plate 302. In other embodiments, it may be possible for θ.sub.1≠θ.sub.2. Sides 322, 324 of top plate 304 are formed at the same angle to the vertical axis or plane A. Therefore, the side piece 318 of the base plate 302 is parallel to the side 322 of the top plate 304 and the side piece 320 of the base plate is parallel to side 324 of the top plate 304. In the embodiment of
(86) In this embodiment, each of the actuators 306, 308, 310, and 312 extends from one of the side pieces 318, 320 of the base plate 302, in a direction toward the top plate 304. For example, in this embodiment, each actuator is secured or coupled to a side piece of the base plate 302 and is oriented at an angle of 90 degrees with respect to a corresponding actuator on the opposite side piece 318 or 320.
(87) A distal end of each actuator 306, 308, 310, and 312 may include a magnetic material. In the embodiment of
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(92) Similarly, the third actuator 310 could be extended a greater distance than the first actuator 306 and the fourth actuator 312 could be similarly extended a greater distance than the second actuator 308, resulting in a downward slant of the top plate 304.
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(95) Although, the embodiments of
(96) In the embodiment of
(97) While any combination of actuator extensions and retractions can be accomplished, in this example, the first and second actuators 406, 408 are extended a greater distance than the third and fourth actuators 310, 312, resulting in an upward tilt at the front of top plate 304.
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(99) While the foregoing has described what are considered to be the best mode and/or other preferred embodiments, it is understood that various modifications can be made therein and that the invention or inventions may be implemented in various forms and embodiments, and that they may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim that which is literally described and all equivalents thereto, including all modifications and variations that fall within the scope of each claim.
(100) It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provide in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.
(101) For example, it will be appreciated that all of the features set out in any of the claims (whether independent or dependent) can combined in any given way.