DE102009035877B4 - compensation actuating - Google Patents

Abstract

The present invention relates to a compensation actuator comprising a movement unit translatable in three spatial directions, at least one actuator, a first solid joint assembly comprising a mechanically coupled to the movement unit, a first simple lever forming solid-state joint assembly (wherein by means of the at least one actuator, the first solid-state joint arrangement deflectable and so that due to this first coupling, the movement unit is translationally deflected in the first spatial direction), and a second solid-body joint assembly comprising a mechanically coupled to the movement unit and / or the first solid-state joint assembly, a toggle lever forming second solid state joint arrangement (wherein by means of the at least one actuator, the second solid state joint arrangement deflectable and thus due to this second coupling, the movement unit is translationally deflectable in the second spatial direction).

Description

The present invention relates to a compensation actuator for performing translatory compensation movements in at least two, preferably in three spatial directions. The compensating actuator according to the invention can be used, for example, for positioning tasks in workpiece machining or in production, in particular in wafer production or for other high-precision assembly tasks.

In mechanical handling devices such as robots, a major problem is usually that they have inaccurate positioning accuracy. Positioning errors can occur statically or process-specifically and must be compensated. This can be done, for example, by using a compensation factor.

In order to increase the positioning accuracy of positioning devices, in particular the positioning units of robots, recourse is made in the prior art to means of calibration, to mechanical replacement models, to temperature compensations or also to compensation axes, for example for vibration damping. Compensation kinematics are also known for positioning tasks. Furthermore, highly dynamic compensation mechanisms in the field of spindle suspensions are known in which the highly dynamic properties of piezo actuators are utilized and harmful influences (for example vibrations due to spindle movement, oscillation rocking due to regenerative rattling, tool displacements due to high lateral machining forces, etc.) are compensated.

From the prior art ( US 7,024,925 B2 In addition, a compensation factor for performing translational compensation movements of a movement unit in three spatial directions is known. This compensation factor comprises actuators and a first solid-state joint assembly and a second. Solid-state joint assembly, which are deflected by the actuators so that the movement unit performs translational movements in two spatial directions. The second solid state articulated assembly includes a solid state articulated assembly that forms a toggle. The first solid state articulated assembly is also implemented with a solid state articulation assembly that forms a toggle.

However, all of these prior art devices and / or methods have their specific disadvantages. For example, positioning errors can not be compensated for in three dimensions or purely translationally in some devices. For others, it is not possible to compensate for positioning errors with high dynamics. High-frequency vibrations can not be compensated in this way. In other methods, the compensation is possible only up to a certain tool and / or workpiece weight. Often the achievable positioning accuracy is limited.

• • statische translatorische Positionierfehler mindestens zweidimensional, bevorzugt dreidimensional ausgleichbar sind,
• • ein hoch dynamischer Ausgleich möglich ist, das heißt hochdynamische Positionier- bzw. Ausgleichbewegungen geregelt möglich sind,
• • dynamische Schwingungskompensationen von hochfrequenten Schwingungen möglich sind,
• • eine mikrometergenaue Positionierung in mindestens zwei, bevorzugt drei Raumrichtungen erreicht werden kann (Absolutgenauigkeit ebenso wie Wiederholgenauigkeit),
• • eine solche Genauigkeit bei einem Industrieroboter in jedem Fall besser als 20 μm beträgt und
• • die entsprechende Genauigkeit auch für höhere Gewichte von zu positionierenden Objekten (z. B. Werkstücken oder Werkzeugen) erreicht werden kann (z. B. Gewichte bis etwa 20 kg).

It is therefore an object of the present invention, based on the prior art, to provide a compensating actuator as well as a method for carrying out translatory compensatory movements with which

• Static translatory positioning errors can be compensated for at least two-dimensionally, preferably three-dimensionally,
• • highly dynamic compensation is possible, ie highly dynamic positioning or compensation movements are possible in a regulated manner,
• • Dynamic vibration compensation of high-frequency vibrations are possible
• A micrometer-accurate positioning in at least two, preferably three spatial directions can be achieved (absolute accuracy as well as repeatability),
• • In any case, such accuracy is better than 20 μm for an industrial robot, and
• • The corresponding accuracy can also be achieved for higher weights of objects to be positioned (eg workpieces or tools) (eg weights of up to 20 kg).

Moreover, it is the object of the present invention to provide a correspondingly accurate device for positioning an object and / or for machining a workpiece using such a compensation factor.

This object is achieved by a compensation actuator according to claim 1, a compensation actuator base assembly according to claim 25, an apparatus for object positioning and / or workpiece machining according to claim 26 and a method for performing translational compensation movements according to claim 27. Advantageous embodiments can be found in the dependent claims. Uses according to the invention emerge from claim 28.

Hereinafter, the present invention will be described first generally, then in the form of a detailed embodiment. In the context of the present invention (the scope of which is defined by the appending claims), the specific combinations of individual features presented in the context of the exemplary embodiment need not be realized exactly in the configuration shown, but can also be realized in other combinations of features. In particular, individual of the Embodiment shown features are also omitted or combined with other, shown as not inclined features in other ways structurally and / or functionally.

In the context of the present invention, the deflectability of an element is understood to mean that this element is directly (or indirectly via other elements) and, for example, by means of an actuator within a stationary coordinate system (x, y, z), ie relative to the origin of this coordinate system. along a trajectory is movable. The movement may thus be a straight-line displacement, a displacement along a curved path, a rotation, etc. Likewise, it is also possible that the center of gravity of the element (relative to the stationary coordinate system) is not moved, but that the element is in itself dilated or contracted. Combinations of movements along a trajectory and such a dilation and / or contraction are possible. If one speaks below of spatial directions x, y, z, the three coordinates of a Cartesian coordinate system are generally meant. If one speaks of a translatory movement in such a spatial direction, it is, unless otherwise stated, a movement which comprises exclusively translational components in this spatial direction. However, this does not exclude that such a movement basically also (usually minor) rotational portions may have.

In the context of the invention, a knee lever is understood to mean a device or an element for force transmission and / or power transmission which comprises at least two one-armed levers with a common end point (usually designed as a movable pivot point), the free ends of the one-armed links Levers which are supported against one or more bodies can be moved under the influence of a force acting on the common end (in the case of two bodies, these are then usually brought closer to each other or away from each other). As a rule, a knee lever used in accordance with the invention is a toggle lever comprising two knee joints (ie, four toggle lever comprising four lever arms arranged in the shape of a rhombus or approximately in the form of a rhombus, wherein the four lever arms are then usually designed such that when a force is applied to two opposite corners of the lozenge, the other two corners of the lozenge move either toward each other - outward force or away from one another - inward force). In the context of the invention, the main axis of such a toggle lever is then generally understood to mean the axis connecting those two opposite corners of the lozenge ("knee joints"), which axis is arranged perpendicularly to the above-described force action direction.

The basic idea of the present invention is translational Pasierungsierfehler z. B. a robot to compensate and to realize a highly accurate (micrometer accurate) positioning of an object relative to another object and / or a fixed coordinate system, that so-called solid joints are arranged in the context of solid-body joint assemblies so that partially the stiffnesses of the solid joints in different directions can be minimized to be deflected by actuators (in particular: piezo actuators). A solid-state gel is understood to mean a body which is characterized by a position with reduced flexural rigidity (which is delimited by adjacent zones which can be regarded as rigid bodies). With such solid-state joints, kinetic pairs can be realized in one part. The reduced bending stiffness is usually realized by a local reduction in cross-section. In this case, the cross section can be reduced only along one or even along two spatial directions; the cross-sectional changes may have different geometric shapes.

The usually small travel ranges of the actuators used are increased by solid-joint-like lever translations formed so as to allow greater compensation movements. The movements of the actuators which are translated or enlarged with the aid of the solid-body joints are transmitted to a movement unit (eg a stage). Thus, according to the invention, an arrangement of different solid-state joint combinations is realized with which translatory compensation movements in several spatial directions are possible. The various gear ratios through the solid-state joints are designed such that an enlargement of the generally small stroke movements of the actuators (for example in the case of the piezo actuator 180 μm) to a multiple value is possible (for example 500 μm).

In particular, other solid-state joints are used in addition to such enlargement-solid-body joints, which provide for a translatory positive guidance (that is, for the prevention of rotational movement parts).

In particular, the compensating actuator according to the invention (hereinafter alternatively also referred to as compensating kinematics) uses different solid-state hinges in conjunction with (or coupled to) actuators, the compensating directions in the first and the second spatial directions (x and y directions) generally being determined by the third spatial direction (z-direction) are worn. As a result, a gear is achieved on lever basis, in which no unwanted distortions and / or tilting of the compensating actuator or the moving movement unit can take place, but only purely translational movements in the three spatial directions.

A compensatory actuator according to the invention can be a series-connected compensatory actuator, in which the preceding axle has its attachment in the respectively following compensation direction (for example, the movement unit is moved in the x-direction by means of a first solid-body joint assembly, the first one The solid joint assembly, including the motion unit, is then moved in the y direction by a second residual joint joint assembly and these two solid joint assemblies together with the gadget are then moved in the z direction by a third solid joint assembly, in which case the third solid joint assembly in the rack will move all of them into the y direction x- and y-direction moving masses: The compensation directions in the x- and y-direction are supported by the z-direction ("serial compensation kinematics").

In this case, each compensation direction or solid-state joint assembly can be operated autonomously. The movement unit (eg end effector on which a machine tool spindle can be placed) can thus be moved in all three spatial directions x, y, z.

According to the invention, a serial, independent arrangement of solid-body joint assemblies is thus preferably realized which realize the compensatory movements in several spatial directions with the aid of lever ratios.

A compensating actuator according to the invention comprises first the at least two, preferably three spatial directions translationally movable moving unit and at least one actuator (usually, an actuator is provided for each spatial direction). A first solid-state joint assembly of the compensation actuator comprises a first solid-body joint arrangement which is mechanically coupled to the movement unit and forms a first simple lever. By means of the at least one actuator, this first solid-body joint arrangement can be deflected, so that the movement unit can be deflected translationally in the first spatial direction (x-direction) on account of the above-described first coupling. A second solid-state joint assembly of the compensation actuator comprises a second solid-body joint arrangement mechanically coupled to the movement unit and / or the first solid-state joint assembly. As a rule, the second solid-state joint arrangement is mechanically coupled directly to the first solid-state joint assembly and the latter in turn mechanically to the movement unit. In this case, there is an indirect coupling of the second solid-state joint assembly to the moving unit. The second solid-state joint arrangement forms a toggle lever and is deflectable with the at least one actuator so that due to the above-described coupling of the second solid-body joint arrangement, the movement unit can be deflected translationally in the second spatial direction (y-direction).

As a rule, the deflections are translational displacements. As a rule, two different actuators are used for deflecting the first solid-body joint arrangement and the second solid-body joint arrangement; In principle, however, it is also conceivable for this purpose a single z. B. via a further lever assembly with the two solid-state joint arrangements coupled actuator.

These two actuators are preferably designed and arranged such that the forces exerted by them on the two solid-body joint arrangements (force F for translatory movement in the x-direction and force F for translatory movement in the y-direction) are parallel relative to one another. For this purpose, z. B. cylindrical piezoelectric actuators with their longitudinal axes in the plane spanned by the x- and y-direction plane spaced from each other and are arranged parallel to each other.

As already described above, the toggle lever used according to the invention is preferably a toggle lever having two knee joints whose individual lever arms are preferably arranged in a diamond shape.

Particularly preferably, the compensation factor has a third solid-body joint assembly for performing a translatory compensation movement also in the z-direction. This third solid-body joint assembly is mechanically (directly or indirectly) coupled to the movement unit. The mechanical coupling of the individual units can be implemented such that the first solid-state joint assembly is mechanically coupled directly to the movement unit, that the second solid-state joint assembly is directly mechanically coupled to the first solid-state joint assembly (and thus indirectly to the movement unit) and that the third solid-state joint assembly directly is mechanically coupled to the movement unit, wherein the third solid-state joint assembly by means of stiffening feet and other solid joints wear the first two solid-state joint assemblies together with the movement unit and translate by means of their third solid-body joint assembly in the z-direction (see below).

Advantageously, this third solid-body joint assembly comprises a third solid-body joint arrangement which forms a second simple lever and is mechanically coupled thereto by means of the movement unit. Advantageously, this third solid-state joint arrangement is then deflected by means of a separate, third (piezo) actuator, thereby generating the z-deflection of the movement unit.

The third actuator advantageously deflects by means of the third solid-body joint arrangement (and preferably also with the aid of stiffening feet) not only the movement unit, but also the first two solid-body joint assemblies in the z-direction.

Advantageously, the force F _z necessary for this purpose is generated perpendicular to the two (parallel) forces F _x , F _y , but also parallel to the xy plane by means of a separate piezo actuator whose (cylindrical shape assumed) longitudinal axis parallel to the xy plane and is arranged perpendicular to the longitudinal axes of the first two actuators, wherein the third piezoelectric actuator is spaced from and arranged below the first two (piezo) actuators. Advantageously, the first and the second solid-body joint assembly together with the movement unit are designed as planar assemblies in one and the same plane, this plane being arranged parallel to the xy plane.

As will be described in detail below, the first solid-state joint assembly advantageously comprises one or more other solid-state joints which are designed and arranged such that the first solid-state joint arrangement (by the direct or indirect mechanical coupling to the movement unit) is a purely translational movement of the coupled movement unit realized a straight section in the first spatial direction x. The same applies advantageously also for the second and / or third solid-body joint assembly.

In all three solid state joint assemblies, such other solid joints (if any) are preferably symmetrical about the moving unit or the first solid joint assembly (first solid joint assembly and second solid joint assembly) or so arranged (third solid joint assembly) that the projections of these further solid joints on the plane in which the moving unit is arranged symmetrically about the latter are arranged around.

In particular, the further solid-state joints of the first, the second and / or the third rest body joint assemblies can each be arranged at the corners of a square or rectangle.

The third solid-body joint arrangement forming the second simple lever is preferably mechanically connected to the movement unit via a plurality of (preferably exactly two) further solid-state joints of the third solid-body joint assembly (that is, coupled thereto). This coupling preferably attacks in the center of gravity and / or in the geometric center of the movement unit.

In a further preferred embodiment, the third solid-body joint assembly comprises a plurality of stiffening feet. Preferably, exactly four such stiffening feet are used. The stiffening feet in each case couple via another solid-body joint to the first solid-body joint assembly and / or the movement unit. The stiffening feet are advantageously arranged in the z-direction and surround the movement unit (possibly together with the first and / or second solid-state joint assembly) symmetrically so that by means of the third solid-body joint arrangement a purely translational displacement of the movement unit in the z-direction (without any x or y-shift shares) can be realized.

For this purpose, advantageously, the points of reduced bending stiffness of the further solid-body joints, via which the stiffening feet are connected or coupled directly or indirectly to the movement unit, are symmetrical, in particular point-symmetrical, around the movement unit (eg along the sides of a square). that the extent (as well as the stiffness) of these points in a plane perpendicular to the z-direction is significantly greater than their extension (and the rigidity) in the z-direction.

Advantageously, the longitudinal axis of the first simple lever (the first solid joint assembly) is parallel to the major axis of the bellcrank of the second solid joint assembly. These two axes advantageously run in one and the same plane parallel to the x-y plane. Also, the longitudinal axis of the second simple lever is advantageously parallel to this plane and / or to the aforementioned two axes, but spaced below the described longitudinal axis of the first simple lever and the main axis of the toggle lever.

In further advantageous embodiments, the first actuator is arranged with its longitudinal axis along the x-direction. The second actuator can be arranged within the lozenge formed by the four lever arms of a diamond-shaped knee lever, wherein its longitudinal axis can also be arranged along the x-direction. The Coupling of the first simple lever or of the first solid-body joint arrangement to the movement unit can be realized by means of a flexibly formed web which is preferably aligned with its longitudinal axis in the x-direction.

Hereinafter, the present invention will be described with reference to an embodiment. Show it:

1 a section through the first solid-state hinge assembly, the second solid-state hinge assembly and the movement unit in the horizontal x, y

2 the same section with a mechanical equivalent circuit of the damping constants, error constants, moving masses and forces

3 a section perpendicular to the horizontal (ie in the vertical y, z) in which the third solid-state joint assembly is recognizable

4 the same section with a mechanical equivalent circuit diagram

5 the principle of stiffening feet 5 a three-dimensional view of the compensating actuator according to the invention of the example shown

7 the mechanical equivalent circuit diagram of the same

8th the use of a compensating actuator according to the invention in an industrial robot system

1 shows a cross section through a compensating actuator according to the invention in a plane defined by the first and second spatial direction (x, y) plane. Visible are the first solid-state joint assembly 4 and the second solid-state joint assembly 5 and the motion unit 2 , All these elements are formed as a flat, arranged in the xy plane, mechanically interconnected or mechanically coupled to each other elements made of aluminum.

The movement unit 2 is formed as a substantially rectangular plate formed for receiving a tool and / or a workpiece. The movement unit 2 is provided in the xy plane with a plurality of openings, which allow the formation of the further solid joints described below. That's the movement unit 2 on two opposite sides over two more solid joints 4f to 4i (hereinafter also referred to as auxiliary joints) mechanically with the surrounding portions of the solid-state hinge assembly 4 connected: The two in the figure on the left side of the movement unit 2 shown auxiliary joints 4f and 4h are there as well as the two auxiliary joints 4g and 4i formed on the right side as meandering, web-shaped solid joint springs. The four auxiliary joints 4f to 4i (following name: " 4f - 4i ") Are point-symmetrical to the center M of the movement unit 2 (which coincides here with the center of gravity of this motion unit) arranged (point symmetry seen in the xy plane).

Also on the other two opposite sides of the rectangle of the movement unit 2 (in the figure at the upper and lower sides of the moving unit 2 ) are two more solid joints 4b - 4e , which are also referred to as main joints hereinafter, arranged. Also these four main joints 4b - 4e are (as seen in the xy plane) point-symmetric to the center M of the motion unit 2 arranged. The four main joints 4b - 4e are also designed as web-shaped solid-state hinge springs, but have seen in the xy plane on a Ω-shaped course.

The main joints 4b - 4e as well as the minor joints 4f - 4i are formed and arranged so that, in a later described in more detail deflection of the moving unit 2 using the first solid-state joint arrangement 4a or the first simple lever H1, a purely translational movement in the x-direction can be realized. These arrangements and shapes (eg, the open Ω shape) were chosen to realize maximum stiffness with maximum motion capability.

At the side in the figure above (at the also the two main joints 4b and 4c are formed) is the moving unit 2 by a flexibly formed web aligned with its longitudinal axis in the first spatial direction (x-direction) and having a first solid-body joint arrangement 4a mechanically connected. This first solid-state joint arrangement 4a forms a first simple lever H1, whose longitudinal axis L is aligned in the second spatial direction, that is perpendicular to the x-direction in the y-direction. The first coupling g1 by means of the flexibly formed web is in this case at one end (end shown on the right) of the lever H1 or the solid-body joint arrangement 4a realized. The arranged at the end of the lever H1 web g1 is symmetrical between the two Hauptgelenkten 4b and 4c to the movement unit 2 or its upper side coupled.

At the opposite end (left end) of the lever H1 is slightly spaced from this end, here an approximately hat-shaped in cross-section opening O shown. This is so designed that a hardened pressure piece can be introduced to it, to which a piezoelectric actuator can be coupled (alignment of the longitudinal axis of the piezoelectric actuator in the x direction, see also 2 ), so that with the aid of this first piezoelectric actuator, the simple mist H1 can be deflected in the x-direction near the left end. This results from the above-described coupling of the first solid-state joint arrangement 4a or the lever H1 by means of the web g1 to the moving unit 2 a translational movement of the movement unit 2 in the x-direction, due to the positive guidance with the main joints 4b - 4e and the auxiliary joints 4f - 4i is designed so that it has exclusively motion components in the x direction. Because the first solid-body joint arrangement 4a is firmly clamped at the outermost left end (seen in the y-direction spaced from the location of the opening O) F, results in the present case, a Hebeübersetzungsverhältnis (see also 2 ) of about 1: 4. Will thus be the first piezoelectric actuator 3a ( 2 ) is deflected by, for example, 150 μm, the result is a deflection of the unit due to the above-described mist starting point O between F and g1 at the right-hand end of the lever g1 2 of 600 μm in the x-direction.

In the case shown, the first solid state joint assembly includes 4 thus the first solid-body joint arrangement 4a (or the lever H1), the clamping section F, the main and the minor joints 4b - 4i , the first coupling portion g1 and other plate portions, these elements and the moving unit 2 surround. Also the movement unit 2 can be considered here as part of the first solid-state joint assembly.

The first solid-state joint assembly 4 (including the movement unit 2 ) is from other solid joints 5b - 5i the second solid-state joint assembly 5 surrounded concentrically and thus to the second solid state joint assembly 5 mechanically coupled. For this purpose, the outer edge portions of the first solid-state joint assembly 4 (the the elements 4a - 4i surrounded) so that the first solid-state joint assembly 4 Overall, in turn, is designed as a substantially rectangular plate member. The two opposite sides of this rectangle seen in the x-direction (the sides shown in the figure left and right) then each have two main joints (the other solid joints 5b - 5e ) on. Both the main joints 5b and 5d the left side as well as the main joints 5c and 5c the right side are there (analogous to the joints 4b - 4e ) formed as a web-shaped, substantially Ω-shaped solid-state spring joints. The main joints 5b - 5e are point-symmetrical to the geometric center of the first solid-state joint assembly 4 including movement unit 2 (this center is not shown here) arranged.

Also on the upper and lower sides of the first solid-state hinge assembly 4 including the movement unit 2 are a total of four minor joints 5f - 5i educated. These are like the minor joints 4f - 4i shaped as web-shaped, meander-shaped solid-state spring joints. Also the minor joints 5f - 5i are point symmetrical to the prescribed center of the first solid state joint assembly 4 including the movement unit 2 arranged.

The major and minor joints 5b - 5i couple the first solid-state joint assembly 4 including the movement unit 2 mechanically to a frame portion R, which is the first solid state joint assembly 4 including the movement unit 2 and the second solid-state hinge assembly 5a (see below) surrounds the Außenumfengsseitig.

Midway between the two main joints 5b and 5d is the left side of the first solid-state hinge assembly 4 or of the rectangular plate section formed by it, mechanically via a second coupling g2 with the second solid-body hinge arrangement 5a and connected via this with the opposite, shown in the figure far left portion of the outer frame R. This second solid-body joint arrangement 5a Forms a two knee joints K1 and K2 having toggle K. The double toggle lever principle shown here is in principle known to the person skilled in the art, so that it can be described with reference to FIG 1 As a result of the fixed connection of the left knee joint K1 of the toggle lever K with the outer frame R, the two knee joints K1 and K2 are moved toward one another along the main axis H of the toggle lever K joining them (reduction of the knee joint distance due to corresponding knee joint K) Power exerted by the piezoelectric actuator 3b , see. 2 ) due to the second mechanical coupling g2 the first solid state joint assembly 4 including the movement unit 2 moved within the frame R to the first knee joint K1, ie moved in the -y direction. Be the two knee joints K1 and K2 with appropriate force through the piezoelectric actuator 3b (see 2 ) moves away from each other, so moves due to the coupling g2 of the entire complex of first solid-state hinge assembly 4 including movement unit 2 in + y direction.

Because the arrangement of the major and minor joints 5b to 5i here quite analogous to that of the main and minor joints 4b to 4i is (former joints are arranged only in the xy plane rotated by 90 °) is also here by means of the coupling of these joints 5b to 5i on the outer frame R a forced guidance which ensures that with appropriate power exercise F _y on the knee lever K is the first solid-state joint assembly 4 including the movement unit 2 a purely translational movement in the second direction of movement, that is, an exclusively linear motion components in the y-direction having movement performs.

On the bottom of the movement unit 2 this carries a cuboid measuring block, not shown here, whose side surfaces are each aligned parallel to one of the three spatial directions x, y and z. Three capacitive sensors are arranged below the movement unit in the immediate vicinity of this and the measuring block and aligned with the Meßklotzflächen. With these sensors can then be a deflection of the movement unit 2 in the coordinate system (x, y, z). The deflection determined in this way then serves as feedback value for a regulating and control device 14 (see. 8th , not shown here).

2 now shows the same cut as 1 , but superimposed with a mechanical equivalent circuit that shows the individual damping constants, spring constants, moving masses, deflection directions as well as the force action directions and the points of application of the forces.

Good to see here is the parallel arrangement of the first piezoelectric actuator 3a and the second piezoelectric actuator 3b spaced apart from each other and parallel to each other and parallel to the xy plane with respect to their two longitudinal axes A1 and A2, respectively. The two piezo actuators 3a . 3b are positioned so that with them the simple lever deflection H1 and the toggle K can be realized. For deflecting the knee lever K is the second piezoelectric actuator with its longitudinal axis A2 perpendicular to the main axis H of the toggle lever ( 1 ) and arranged concentrically within the individual lever arms of the toggle lever. The through the second piezoelectric actuator 3b generated deflection force F _y is thus here as in the first piezoelectric actuator (force F _x ) also directed in the first spatial direction x. However, since it acts on the two opposing ends of the individual lever arms of the knee lever K facing away from the knees K1 and K2, this force action in the first spatial direction causes a deflection of the first solid-body joint assembly 4 including the movement unit 2 effected in the second spatial direction y. The through the first piezoelectric actuator 3a Deflection force F _x generated in the direction of its longitudinal axis A 1 or the x-direction implements the above-described deflection of the first simple lever H 1 or of the first solid-body joint arrangement 4a ,

The functional principle of the solid-body joint arrangement for the x-compensating movement is thus a simple lever H1. The difficulty here was, among other things, the actually caused by this lever circular motion in a purely translational deflection of the movement unit 2 to convict. This is due to the flexible web g1 in conjunction with the main and auxiliary joints 4b to 4i realized. The y-deflection is a parallel deflection by means of the toggle K, which is acted upon by the force F _y . By using a toggle lever and the simple lever H1, the relative arrangement of these two levers to each other and the above-described arrangement of the two piezo actuators 3a and 3b The assemblies shown can be arranged in parallel and in a very small space. On the other hand, the use of a toggle lever also has the advantage that no rotational movement is to be taken into account in the y-direction, so that a very stable positive guidance in the y-direction can be achieved in the manner shown. The assemblies responsible for the compensation in the x-direction and in the y-direction are thus mechanically connected or coupled to one another in such a way that a serial compensation kinematics results.

3 and 4 , each one cut through the in 1 and 2 shown compensating actuators perpendicular to the xy plane in the yz plane show that the compensating actuator shown for performing translational compensating movements in all three spatial directions x, y, z is formed.

This is a third solid-body joint assembly 6 provided a third solid-state joint assembly 6a includes. This solid-state joint arrangement 6a is formed in the form of a second simple lever H2 whose longitudinal axis (cf. 4 ) is aligned in the y-direction. The third solid-body joint arrangement 6a or the lever H2 is spaced from the in 1 and 2 plate elements shown and arranged under half of the same.

At one end of the lever H2 (the in 3 . 4 right) is the lever H2 at its top over two more solid joints 6c . 6b {double foldable solid joint assembly) mechanically via an intermediate plate with the underside of the moving unit 2 connected or coupled to the latter (third coupling g3). The third coupling g3 is here directly below the geometric center point or center of gravity M of the movement unit 2 (And the intermediate plate, all piezo actuators and, in a machine tool, the spindle), ie in the middle of the movement unit 2 educated. At the other end of the lever H2 (shown in the pictures on the left) this is mechanically on its upper side via another solid-body joint (simply bendable solid-state joint 6h ) connected to a bridge-shaped structure. This fixed fixation on the bridge-shaped structure ensures that the lever in undeflected rest position has a clearance to the ground, so hanging freely and only at its two ends on the solid joints 6h on the one hand and 6c . 6b on the other hand, on the bridge-shaped element or on the movement unit 2 is suspended together with the intermediate plate.

At the left end of the third solid-body joint arrangement or the lever H2 is a third piezoelectric actuator 3c with its longitudinal axis parallel to the longitudinal axis of the lever H2 arranged so that a longitudinal extension of the piezoelectric actuator 3c along its longitudinal axis causes a deflection of the second simple lever H2. Due to the above-described arrangement thus causes an expansion of a third piezoelectric actuator 3c in the + y direction, a deflection of the second simple lever H2 substantially in this same direction and thus by the translation or deflection by means of the other solid joints 6c and 6b and the mechanical coupling to the moving unit 2 including the intermediate plate, a deflection of the latter upwards, ie in the -z direction.

The third solid-body joint assembly 6 Thus, in the case shown, the third solid-body joint arrangement 6a or the lever H2, the other solid joints 6b . 6c and 6h as well as the third piezoelectric actuator 3c ,

In addition, the third solid-body joint assembly includes 6 four individual stiffening feet 7a to 7d (of which in 3 and 4 only the two feet 7c and 7d are visible because the two feet 7a and 7b are arranged lying behind them). The stiffening feet 7a to 7d are formed as in the z-direction elongated cuboid, placed at the corners of a (lying parallel to the xy-plane) square and carry in the 1 . 2 shown assemblies 2 . 4 and 5 including the intermediate plate and all actuators (and possibly the spindle). For this purpose, each of the four stiffening feet at the top exactly one more solid joint (reference numeral 6d to 6g ) on.

This results in a four-position mechanical coupling (fourth coupling g4) between the stiffening feet 7a to 7d on the one hand and the two solid-body joint assemblies 4 and 5 (including the movement unit 2 ) on the other hand on the solid joints 6d to 6g ,

5 shows the formation of the other solid joints 6d to 6q as well as the arrangement of the same in detail. Each of these solid-state hinges has a stiffened longitudinal axis (stiffening axis) aligned parallel to the xy plane and, due to the double-U-shaped cross section, in a plane perpendicular to this stiffened longitudinal axis (this plane is in FIG 5 shown on the left) perpendicular to two mutually perpendicular, compliant directions. The stiffened longitudinal axes of the four solid-state joints 6d to 6g are each centered on the four sides of a square arranged (see 5 right). This results in a point-symmetrical arrangement of the four stiffening axes of the elements 6d to 6g relative to a point P which is in the z-direction just below the center M of the moving unit 2 is arranged (approximately at the height of the other solid-state joint 6b , please refer 3 ).

Due to the above-described arrangement, the four stiffening feet are used 7a to 7d for additional stiffening of the compensation factor 1 in the z direction. As a result, processing forces are intercepted on the one hand, but also allows a uniform movement in the z-direction: Since the stiffening feet and their stiffening axes are arranged symmetrically to the force application point at the level of the geometric center M, it is ensured that upon deflection of the second simple lever H2 by means of the piezo actuator 3c the thereby over the further solid joints 6c and 6b in the movement unit 2 and the intermediate plate coupled force a movement of the assemblies 2 . 4 and 5 results, which is directed exclusively in -z direction. A rotation and / or tilting about the z-axis is thus prevented by the arrangement of the stiffening feet or their stiffening axes in the square (very rigid direction of rotation). The main and auxiliary joints on the one hand and the stiffening axes of the feet on the other hand are arranged at an angle of 45 ° to each other. Tilting around the x and y axes is also minimized.

The 3 to 5 thus show the mechanical concept of a z-lifting unit of the compensating actuator according to the invention 1 in which a simple lever H2 by means of a piezoelectric actuator 3c deflected and this deflection, which is actually a circular motion, through the other solid joints 6c and 5b is translated into the purely translatory z-motion. The four stiffening feet serve to optimize this power transmission (anti-twist and anti-tilt).

4 shows once again a mechanical equivalent diagram of the z-lifting unit, in which the individual damping constants, spring constants, masses and force and attack points can be seen. The 3 and 4 also show one on top of the movement unit in the top right corner 2 arranged object (here: tool spindle), by a movement of the movement unit 2 translationally in the three spatial directions x, y and z can be positioned highly accurately.

6 shows a three-dimensional view of the compensation factor 1 of the 1 to 5 ,

7 finally shows the mechanical equivalent circuit of the serial three-dimensional compensation kinematics 1 of the 1 to 6 : The individual translation directions are connected in series, the preceding axis has its attachment to the respective subsequent compensation direction (the y-direction moves all moving in the x-direction with, the z-movement moves everything in the x- and y-direction Moved with The x-actuator thus only has to move the mass m _x , the y-actuator the masses m _x and m _y , the z-actuator finally all three masses m _x , m _y and m _z together).

c denotes the damping constants of the system in the three directions, d denotes the spring constants in the individual directions, m denotes the masses of the system to be moved in each direction, and F denotes the force and the points of application of the same: The knee-lever principle in y Direction and the two simple leverage principles in the x and z directions are indicated here only schematically.

Of course, it is also possible, the exemplified Ausgleichsaktorik 1 to realize only with the first and the second solid-state joint assembly (two-dimensional compensation factor for an x and y compensation).

A basic machine concept in which the above-described compensatory actuation can be used is in 8th shown: An industrial robot 13 carries at the end of his robotic arm 12 a tool 11 with which a workpiece 9 to be edited. However, it is also possible for the robot to guide the workpiece and the compensation actuator to guide the tool (not shown here). The workpiece 9 is on the movement unit 2 (not shown here) one according to the 1 to 7 trained compensation factor 1 , in turn, on a solid pedestal 10 is placed.

The problem here is the distance between tool to be controlled 11 and workpiece 9 , with disturbances, for example, by unwanted vibrations of the robot arm 12 (eg due to its own weight and machining forces). To compensate for these disturbances or to compensate, is with an absolute sensor 15 both the absolute position of the tool 11 , as well as the absolute position of the workpiece 9 determined in the room. Using the control and regulation device 14 , which with the data of the absolute sensors both the movement of the robot arm 12 as well as the movement of the compensation factor or the translational compensation by the movement unit 2 controls, by performing translational compensatory movements in all three spatial directions, the disturbance variables or undesirable deviations of the tool 11 from his predetermined target path in real time, so be highly dynamically balanced by the workpiece 9 by means of the movement unit 2 is moved accordingly compensatory. From the workpiece 9 Thus, the tool to be machined moves 11 highly accurate on its target path.

• • Durch die Kombination aus mindestens einem einfachen Hebel und einem Kniehebel wird auf einfache und hochgenaue Art und Weise eine translatorische Zwangsführung in mindestens zwei Dimensionen realisiert.
• • Die hierfür notwendigen Baugruppen können aufgrund der vorbeschriebenen Anordnung sowie der Verwendung eines Kniehebels auf geringem Bauraum untergebracht werden, so dass sich eine Ausgleichsaktorik mit sehr kompakter Bauweise realisieren lässt.
• • Die gezeigte Ausgleichsaktorik kann durch geeignete Materialwahl auch für vergleichsweise hohe Gewichte von bis zu ca. 20 kg für die zu bewegenden Objekte realisiert werden, ohne dass hierdurch die hohe Positionsgenauigkeit (von typischerweise einigen Mikrometern bis einigen 10 Mikrometern) gefährdet wird.
• • Sowohl statisch als auch dynamisch sind somit translatorische Positionierfehler dreidimensional ausgleichbar. Insbesondere können auch hochfrequente Schwingungen dynamisch (bei geeigneter Ausbildung des Regelungs- und Steuerungsmechanismus 14) kompensiert werden. Ein solcher dynamischer Ausgleich ist bis hin zu mehreren hundert Hertz möglich.

Compared to the compensation methods known from the prior art, the present invention has a number of significant advantages:

• • Due to the combination of at least one simple lever and a toggle lever, a translatory positive guidance in at least two dimensions is realized in a simple and highly accurate manner.
• • The necessary assemblies can be accommodated in a small space, due to the above-described arrangement and the use of a toggle lever, so that it is possible to realize a Ausgleichsaktorik with very compact design.
• • By means of a suitable choice of material, the balancing actor shown can also be realized for comparatively high weights of up to approx. 20 kg for the objects to be moved, without jeopardizing the high position accuracy (typically from a few micrometers to a few tens of micrometers).
• • Both statically and dynamically, translational positioning errors can thus be compensated in three dimensions. In particular, high-frequency vibrations can dynamic (with a suitable design of the control and control mechanism 14 ) are compensated. Such a dynamic compensation is possible up to several hundred hertz.

The compensation actuator can be used in conjunction with industrial robots so that the latter can perform highly accurate machining processes. Examples include the milling of components, laser cutting or drilling processes. However, the compensation kinematics can be used quite generally in the range of any micrometer-accurate positioning tasks, including outside of robotics.

Claims (28)

For carrying out translatory compensatory movements in a first (x) and in a second spatial direction (y), preferably also in a third spatial direction (z), compensatory actuators ( 1 ), comprising: a movement unit translatable in the first (x) and second (y), preferably also in the third spatial direction (z) ( 2 ) at least one actor ( 3a . 3b . 3c ), a first solid state joint assembly ( 4 ) comprising a mechanical to the movement unit ( 2 ) coupled, a first simple lever (H1) forming the first solid-state hinge assembly ( 4a ), wherein by means of the at least one actuator ( 3a . 3b . 3c ) the first solid state joint assembly ( 4a ) and thus due to this first coupling (g1) the movement unit ( 2 ) translationally in the first spatial direction (x) is deflectable, and a second solid-state joint assembly ( 5 ) comprising a mechanical to the movement unit ( 2 ) and / or the first solid state joint assembly ( 4 ) coupled, a toggle lever (K) forming the second solid-state joint assembly ( 5a ), wherein by means of the at least one actuator ( 3a . 3b . 3c ) the second solid-state joint arrangement ( 5a ) and thus due to this second coupling (g2) the movement unit ( 2 ) translationally in the second spatial direction (y) is deflected. Ausgleichsaktorik according to the preceding claim, characterized in that the first solid-state joint assembly ( 4 ) a first actor ( 3a ), by means of which the first solid-state joint arrangement ( 4a ) and that the second solid state joint assembly ( 5 ) a second actuator ( 3b ), by means of which the second solid-body joint arrangement ( 5a ) is deflectable, wherein preferably the first and the second actuator ( 3a . 3b ) are designed and arranged such that they can be applied to the solid-state joint arrangements ( 4a . 5a ) exerted and / or applied forces (F _x , F _y ) are parallel relative to each other. Ausgleichsaktorik according to any one of the preceding claims, characterized in that the toggle (K) is a two knee joints (K1, K2) exhibiting toggle, which is preferably formed approximately diamond-shaped with the two knee joints (K1, K2) at opposite corners of the rhombus. Ausgleichsaktorik according to any one of the preceding claims, characterized in that by means of the at least one actuator ( 3a . 3b . 3c ), preferably by means of the second actuator ( 3b ), the second solid-state hinge assembly ( 5a ) and thus due to the second coupling (g2) not only the movement unit ( 2 ), but also the first solid-state joint assembly ( 4 ) or at least portions thereof translationally in the second spatial direction (y) are deflected. Ausgleichsaktorik according to one of the preceding claims, characterized in that the Ausgleichsaktorik for performing translational compensation movements in three spatial directions (x, y, z) is formed by providing a third solid-state joint assembly ( 6 ) comprising a mechanical to the first solid-state hinge assembly ( 4 ), the second solid-state joint assembly ( 5 ) and / or the moving unit ( 2 ) coupled, a second simple lever (H2) forming the third solid-body hinge assembly ( 6a ), wherein by means of the at least one actuator ( 3a . 3b . 3c ) the third solid-body joint arrangement ( 6a ) and thus due to this third coupling (g3) the movement unit ( 2 ) translationally in the third spatial direction (z) is deflectable. Compensation actuator according to the preceding claim, characterized in that the third coupling (g3) between the third solid-body joint arrangement ( 6a ) and the moving unit ( 2 ) is realized and / or that by means of at least one actuator ( 3a . 3b . 3c ), preferably by means of the third actor ( 3c ), the third solid-body joint arrangement ( 6a ) and thus due to the third coupling (g3) not only the movement unit ( 2 ), but also the first and / or the second solid-state joint assembly ( 4 . 5 ) or at least portions thereof translatable in the third spatial direction (z) is / are. Compensation actuator according to one of the two preceding claims, characterized in that the first solid-state joint assembly ( 4 ) a first actor ( 3a ), by means of which the first solid-state joint arrangement ( 4a ) is deflectable, that the second solid-body joint assembly ( 5 ) a second actuator ( 3b ), by means of which the second solid-body joint arrangement ( 5a ) and that the third solid-state joint assembly ( 6 ) a third actor ( 3c ), by means of which the third solid-body joint arrangement ( 6a ) is deflectable, wherein preferably the first, second and third actor ( 3a . 3b . 3c ) are designed and arranged such that the first and second actuators ( 3a . 3b ) to the first and second solid-state hinge assemblies ( 4a . 5a ) exerted and / or exerted two forces (F _x , F _y ) are parallel relative to each other and that the third actuator ( 3c ) on the third solid-body joint arrangement ( 6a ) exerted and / or applied force (F _z ) to these two forces (F _x , F _y ) is perpendicular and preferably also in one and the same plane as these two forces (F _x , F _y ) is formed. Compensation actuator according to one of the preceding claims, characterized in that the second solid-state joint assembly ( 5 ) on the first solid-state joint assembly ( 4 ) is attached. Ausgleichsaktorik according to any one of the preceding claims, characterized in that the second and the first solid-state joint assembly ( 5 . 4 ) are formed as planar assemblies in one and the same, preferably by the first and the second spatial direction spanned plane (x, y) or a parallel plane thereof. Ausgleichsaktorik according to one of claims 5 to 9, characterized in that the first, the second and / or the third solid-state joint assembly ( 4 . 5 . 6 ) one or more further solid-state joints (e) ( 4b . 4c , ..., 5b . 5c , ..., 6b . 6c , ...) which is / are designed and arranged in such a way that the respective solid-body articulated arrangement ( 4a . 5a . 6a ) purely translationally, ie along an exclusively straight section without any curve portion, in the respective spatial direction (x, y, z) is deflected. Ausgleichsaktorik according to the preceding claim, characterized in that the first solid-state joint assembly ( 4 ) several symmetrical about the movement unit ( 2 ), preferably point-symmetrically to the center of gravity and / or to the geometric center (M) of the movement unit ( 2 ), more solid joints ( 4b . 4c , ...), wherein preferably the first solid-state joint assembly ( 4 ), these other solid joints ( 4b . 4c , ...) and / or the movement unit ( 2 ) are formed as planar assemblies in one and the same, preferably by the first and the second spatial direction spanned plane (x, y) or a parallel plane thereof. Compensation actuator according to one of the two preceding claims, characterized in that the second solid-state joint assembly ( 5 ) several symmetrically about the first solid-state joint assembly ( 4 ) together with the movement unit ( 2 ), preferably point-symmetrically to the center of gravity and / or to the geometric center (M) of the first solid-state joint assembly (FIG. 4 ) together with the movement unit ( 2 ), more solid joints ( 5b . 5c , ...), wherein preferably the second solid-state joint assembly ( 5 ), these other solid joints ( 5b . 5c , ...) and / or the first solid-state joint assembly ( 4 ) together with the movement unit ( 2 ) are formed as planar assemblies in one and the same, preferably by the first and the second spatial direction spanned plane (x, y) or a parallel plane thereof. Compensation actuator according to one of the three preceding claims, characterized in that the third solid-body joint assembly ( 6 ) a plurality, preferably exactly two, of the second simple lever (H2) forming third solid-body hinge assembly ( 6a ) mechanically to the moving unit ( 2 ) coupling, further solid joints ( 6b . 6c ) having. Ausgleichsaktorik according to the preceding claim, characterized in that the third mechanical coupling (g3) in the center of gravity and / or geometric center (M) of the movement unit ( 2 ) and / or one with the movement unit ( 2 ) connected intermediate plate on the moving unit ( 2 ) and / or the intermediate plate attacks. Compensation actuator according to one of the preceding five claims, characterized in that the third solid-state joint assembly ( 6 ) several, preferably exactly four, each about exactly one other solid-state joint ( 6d . 6e . 6f . 6g ) mechanically to the first solid-state joint assembly ( 4 ), the second solid-state joint assembly ( 5 ) and / or the moving unit ( 2 ) coupled stiffening feet ( 7a . 7b . 7c . 7d ). Ausgleichsaktorik according to the preceding claim, characterized in that the stiffening feet ( 7a . 7b . 7c . 7d ) are column-shaped and arranged with their longitudinal axis in each case perpendicular to the plane defined by the first and the second spatial direction plane (x, y) and / or that the stiffening feet ( 7a . 7b . 7c . 7d ) are arranged so that their parallel projections on this plane (x, y) symmetrically about the center of gravity and / or the geometric center (M) of the movement unit ( 2 ), preferably point-symmetrical to this center of gravity and / or geometric center (M), come to rest. Ausgleichsaktorik according to one of the two preceding claims, characterized in that the points of reduced flexural rigidity of the four stiffening feet ( 7a . 7b . 7c . 7d ) mechanically to the first solid-state joint assembly ( 4 ), the second solid-state joint assembly ( 5 ) and / or the moving unit ( 2 ) coupling (g4) four further solid-state joints ( 6d . 6e . 6f . 6g ) along the four sides of a symmetrical about the center of gravity and / or the geometric center (M) of the moving unit ( 2 ), the moving unit ( 2 ) along with the first solid-state joint assembly ( 4 ) and / or the moving unit ( 2 ) including the first and second solid state joint assemblies ( 4 . 5 ), preferably point-symmetrical to this center (s) and / or center of gravity (s), of lying rectangles. Ausgleichsaktorik according to any one of the preceding claims, characterized in that the longitudinal axis (L) of the first simple lever (H1) of the first solid-body joint arrangement ( 4a ) parallel to the main axis (H) of the toggle lever (K) of the second solid-body joint arrangement ( 5a ), wherein both axes (L, H) are preferably arranged in the plane spanned by the first and second spatial directions (x, y) or a parallel plane thereof. Ausgleichsaktorik according to one of claims 3 to 18, characterized in that the first actuator ( 3a ) is arranged with its longitudinal axis (A1) along the first spatial direction (x) and that the second actuator ( 3b ) within the area of the toggle lever (K) spanned by the rhombus according to claim 3 and with its longitudinal axis (A2) also along the first spatial direction (x). Ausgleichsaktorik according to any one of the preceding claims, characterized in that the first coupling (g1) by means of a flexibly formed, preferably with its longitudinal axis in the first spatial direction (x) aligned web is formed. Ausgleichsaktorik according to one of claims 5 to 20, characterized in that the third solid-body joint assembly ( 6 ) as a the motion unit ( 2 ), the first solid-state joint assembly ( 4 ) and the second solid state joint assembly ( 5 ) carrying assembly is realized and / or that the movement unit ( 2 ) as part of the first solid state joint assembly ( 4 ) is trained. Ausgleichsaktorik according to any one of the preceding claims, characterized in that at least one of the actuators ( 3a . 3b . 3c ), preferably all of the actuators (a) piezoelectric actuator (s) is / are. Ausgleichsaktorik according to any one of the preceding claims, characterized in that the. first, the second and the third spatial direction (x, y, z) are not rectified in pairs, wherein preferably these three spatial directions (x, y, z) are perpendicular to each other, so coincide with the directions of a Cartesian coordinate system. Ausgleichsaktorik according to any one of the preceding claims, characterized in that the movement unit ( 2 ) comprises a stage and / or an object holder. Compensation actuator base assembly comprising a compensation actuator according to one of the preceding claims, characterized in that the compensation factor ( 1 ) no actor ( 3a . 3b . 3c ), but for accommodating at least one such actuator ( 3a . 3b . 3c ) as described in one of the preceding claims. Device for positioning an object and / or for machining a workpiece ( 9 ), in particular an industrial robot system, comprising a compensation actuator or a compensating actuator base assembly according to claim 25, characterized in that the movement unit ( 2 ) is designed as a receptacle for the object and / or as an effector, with which the workpiece ( 9 ) and / or a tool provided for this purpose can be received. Method for carrying out translatory compensation movements in a first (x) and in a second spatial direction (y), preferably also in a third spatial direction (z) with a compensation factor ( 1 ), characterized in that the compensation factor ( 1 ) is designed according to one of the preceding Ausgleichsaktorikansprüche. Use of a compensation factor ( 1 ), a compensation actuator base assembly, a device for positioning an object and / or for machining a workpiece ( 9 ) and / or a method according to one of claims 26 to 27 for positioning a component, in particular for positioning the component during milling, laser cutting and / or drilling of the component.

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