DE102009035877A1 - Balance actuating element for use in industrial robot system for e.g. positioning object, has joint arrangement deflectable by actuator, and movement unit deflectable in spatial directions due to coupling of joint assembly - Google Patents

Abstract

The element (1) has a movement unit (2) translatory movable in spatial directions (X, Y). A solid joint assembly (4) includes a solid joint arrangement (4a) forming a lever (H1), and is mechanically coupled to the movement unit. Another solid joint assembly (5) includes a solid joint arrangement (5a), and is mechanically coupled to the movement unit and/or the former joint assembly. The joint arrangement of the latter joint assembly is deflectable by an actuator, and the movement unit is translatory deflectable in one of spatial directions due to coupling of the latter joint assembly. The actuator is formed as a piezoactuator. Independent claims are also included for the following: (1) a device for positioning an object and/or for machining a workpiece (2) a method for executing translatory balance movements in spatial directions.

Description

The The present invention relates to a compensation actuator for Carry out of translational compensatory movements in at least two, preferably in three directions. The compensatory actuator according to the invention can, for example for positioning tasks in workpiece machining or in production, especially in wafer production or for others high-precision Assembly tasks are used.

at mechanical handling devices such as robots is usually a big problem in that they have an inaccurate positioning accuracy. Positioning errors can be static or process-specific and must be compensated. This can for example be done using a compensation factor.

Around the positioning accuracy of positioning, in particular Increasing the positioning units of robots is known in the art on means of calibration, on mechanical replacement models, on temperature compensations or used on compensating axles, for example, for vibration damping. For positioning tasks Compensation kinematics are also known. Furthermore, highly dynamic Balancing mechanisms in the field of spindle suspensions known in which the highly dynamic properties of piezo actuators are exploited and harmful influences (For example, vibrations by spindle movement, Schwingungsaufschaukeln by Regenerative rattling, tool displacements due to high lateral Machining forces, etc.) be compensated.

Alles these known from the prior art devices and / or However, processes have their specific disadvantages. So are at Some devices do not have positioning errors in three dimensions or not translationally compensable. With others is no Compensation of positioning errors with high dynamics possible. High frequency Vibrations can so can not be compensated. Other methods are balancing only up to a certain tool and / or workpiece weight possible. Often is also the achievable positioning accuracy 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).

Furthermore It is the object of the present invention to provide a corresponding exact device for positioning an object and / or for Machining a workpiece using such compensation factoring.

These The object is achieved by a compensation actuator according to claim 1, a Ausgleichsaktorik-, basic assembly according to claim 25, a device for object positioning and / or workpiece machining according to claim 26 and a method for performing translational compensatory movements according to claim 27 solved. Advantageous embodiments can be found in the dependent claims. Uses according to the invention result from claim 28.

following The present invention is first general, then in shape a detailed embodiment described. The presented in the context of the embodiment specific combinations of individual features must be within the scope of the present Invention (the scope of which is defined by the appended claims is) not exactly in the configuration shown, but you can be realized in other combinations of features. Especially can single in the embodiment also be omitted or shown with other features shown as not shown, features in other ways structurally and / or functionally combined.

In the context of the present invention, the deflectability of an element is understood to mean that this element is directly (or else indirectly via other elements) and, for example, by means of an actuator within a fixed 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 in itself is 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 we speak of a translational movement in such a spatial direction, then, unless otherwise stated, a movement 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.

Under a knee lever is within the scope of the invention, a device or an element for power transmission and / or power transmission understood, the / at least two-armed lever with a common End point (usually designed as a movable pivot) comprises the free ends of the one-armed lever, which against one or several bodies supported are under the influence of an attacking force at the common end can be moved (with two bodies these are then usually approximated or removed from each other). In general, it is a used in the invention Knee lever around a knee lever having two knee joints (ie a four in the form of a rhombus or approximately in the form of a Loom arranged lever arms comprehensive toggle lever, with the four lever arms then usually are designed so that when exercising a Force on two opposite Corners of the rhombus are the other two corners of the rhombus either move towards each other - after Outside directed force - or move away from each other - after internal force). Below the main axis of such a toggle lever is in the context of the invention then usually those two opposite Corners of the lozenge ("knee joints") connecting Axis understood that perpendicular to the above-described force action direction is arranged.

The basic idea of the present invention is translational Positioning error z. B. a robot to compensate and a highly accurate (micrometer accurate) positioning of an object relative to a another object and / or a stationary coordinate system thereby to realize that so-called solid-state joints in the context of solid-state joint assemblies so be arranged that partially the rigidities of the solid joints can be minimized in different directions in order to be controlled by actuators (in particular: Piezo actuators) to be deflected. Under a solid-body joint becomes a body understood by a body with reduced bending stiffness is characterized (which is different from adjacent zones, which are regarded as rigid bodies can be demarcates). With such solid joints kinmatic Couples can be realized in one part. The reduced bending stiffness is usually realized by a local cross-sectional reduction. The cross section can only along one or along two Spatial directions be reduced; the cross-sectional changes can be different have geometric shapes.

The usually small adjustment paths of the actuators used are by solids articulated formed leverage ratios enlarged to so larger compensatory movements to enable. The translated with the help of solid joints or enlarged movements the actuators are transferred to a motion unit (eg a stage). Thus, according to the invention is an arrangement various solid-body joint combinations realized, with the translational compensatory movements in several Spatial directions are possible. The various gear ratios through the solid joints are designed so that an increase in the usually small strokes of the actuators (eg in the case of the piezo actuator 180 μm) to a multiple value possible is (eg 600 μm).

Especially become next to such magnifying solid joints also other solid joints used that for a translatory forced operation (ie for the avoidance of rotational movement parts).

Especially sets the Ausgleichsaktorik invention (hereinafter alternatively referred to as compensation kinematics) different solid joints in connection with (or coupled to) actuators, wherein the compensation directions in the first and the second spatial direction (x and y direction) in usually be carried by the third spatial direction (z-direction). As a result, a gear is achieved on lever basis, in which no undesirable Twists and / or tilting the Ausgleichsaktorik or the Moving movement unit can take place, but purely purely translatory 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 respective subsequent 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-body joint assembly together with the movement unit is then made by means of a second solid-body joint assembly in the y direction, and these two solid joint assemblies, including the motion unit, are then moved in the z direction by a third solid state link assembly. In this case, therefore, the third solid-state joint assembly typically moves all masses moved in the x and y directions: the x and y directionalities are borne by the z direction ("serial compensation kinematics").

there Each compensation direction or solid-state joint assembly can become autonomous operate. The motion 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.

Thus, according to the invention prefers a serial, independent arrangement of solid state joint assemblies implements the compensatory movements with the aid of lever ratios realize in several directions.

A Compensating actuator according to the invention comprises first in at least two, preferably three spatial directions translational movable movement unit and at least one actuator (usually is for each spatial direction provided an actuator). A first solid state joint assembly the Ausgleichsaktorik includes a mechanically to the moving unit coupled, a first simple lever forming first solid-state hinge assembly. By means of the at least one actuator, this first solid-state joint arrangement deflectable, so that is due to the above, first coupling the movement unit translationally in the first spatial direction (x-direction) deflectable. A second solid-body joint assembly the Ausgleichsaktorik includes a mechanical to the moving unit and / or the first solid-state joint assembly coupled, second solid joint assembly. As a rule, the second solid-state joint arrangement is immediate mechanically with the first solid-state joint assembly coupled and the latter in turn mechanically to the moving 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 assembly forms a toggle and is so deflected with the at least one actuator, that thus due to the above-described coupling of the second solid-body hinge assembly the movement unit translationally in the second spatial direction (y-direction) is deflectable.

In As a rule, the deflections are translational Shifts. Typically, to deflect the first solid joint assembly and the second solid-state hinge assembly two different actuators used; In principle, however, it is the same conceivable for this a single z. B. over another lever assembly coupled to the two solid-state hinge assemblies Actuator insert.

These two actuators are preferably designed and arranged such that the forces exerted by them on the two solid-body joint arrangements (force F _x for the translational movement in the x direction and force F _y for the 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 is used in accordance with the invention Knee lever preferably around a knee lever having two knee joints, whose individual lever arms are preferably arranged in diamond shape.

Especially The compensation actuator preferably has a third solid-body joint assembly to perform a translational compensation movement in the z direction. Also this third solid-body joint assembly is (directly or indirectly) mechanically to the movement unit coupled. The mechanical coupling of the individual units can to be realized so that the first solid-state joint assembly directly is mechanically coupled to the movement unit that the second Flexure hinge assembly mechanically directly to the first solid-state joint assembly (and thus indirectly to the moving unit) is coupled and that the third Flexure hinge assembly is mechanically coupled directly to the movement unit, wherein the third solid-state joint assembly by means of stiffening feet and further solid joints the first two solid-state joint assemblies carry along with the movement unit and by means of their third solid-body joint arrangement translational in the z-direction can move (see below).

advantageously, includes this third solid-state joint assembly a third solid-state hinge arrangement, which forms a second simple lever and this mechanically is coupled with the movement unit. Advantageously, then this third solid-body articulation arrangement deflected by a separate, third (piezo) actuator and thereby generates the z-deflection of the moving unit.

Advantageously, by means of the third solid-body joint arrangement (and preferably also with the aid of stiffening feet), the third actuator directs not only the movement unit but also the first two solid-body joint assemblies 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, are the first and second solid-state joint assemblies together with the Movement unit as planar assemblies in one and the same plane formed, wherein this plane is arranged parallel to the x-y plane.

As Described in detail below, the first solid state joint assembly advantageously one or more other solid joints formed and arranged such that the first solid-state hinge assembly (through the direct or indirect mechanical coupling the movement unit) a purely translational movement of the coupled Moving unit along a straight section in the first spatial direction x realized. The same applies advantageously also for the second and / or third solid state joint assembly.

at all three solid-state joint assemblies are such other solid-state joints (if present) preferably symmetrical about the movement unit or the first solid-state joint assembly around (first solid-state joint assembly and second solid-state joint assembly) or so arranged (third solid-body joint assembly) that the projections of these other solid joints on that plane in which the movement unit is arranged symmetrically around the latter are arranged around.

Especially can the other solid joints the first, second and / or third solid state joint assemblies be arranged at the corners of a square or rectangle.

Prefers is the third simple joint assembly forming the second simple lever over a plurality (preferably exactly two) further solid joints of the third solid state joint assembly mechanically connected to the movement unit (thus coupled to this). This coupling preferably engages in the center of gravity and / or in the geometric center to the movement unit.

In Another preferred design, the third solid-body hinge assembly several stiffening feet on. Preferably, exactly four such stiffening feet are used. Pair the stiffening feet each case about another solid-state joint to the first solid state joint assembly and / or the movement unit. The stiffening feet are advantageously arranged in z-direction and surround the movement unit (possibly together with the first and / or second solid state joint assembly) symmetrically such that by means of the third solid-body joint arrangement a pure translational displacement of the moving unit in the z-direction (without any x or y shift shares) can.

For this are advantageously the locations of reduced bending stiffness the other solid joints, on the the stiffening feet indirectly or are directly connected or coupled with the movement unit, symmetrical, in particular point-symmetrical, about the movement unit around (eg along the sides of a square) that the extent (as well as the stiffness) of these places in a Plane perpendicular to the z-direction is significantly larger than its extension (as well as the stiffness) in z-direction.

advantageously, extends the longitudinal axis of the first simple lever (the first solid joint assembly) in parallel to the main axis of the toggle lever of the second solid-state hinge assembly. These Both axes are advantageously in one and the same Plane parallel to the x-y plane. Also the longitudinal axis of the second simple Levers runs advantageously parallel to this plane and / or to the aforementioned both axes, but spaced below the described longitudinal axis the first simple lever and the main axis of the bell crank.

In Further advantageous embodiments is the first actuator with its longitudinal axis along the x-direction arranged. The second actuator can be within the through the four lever arms formed rhombus of a rhomboid trained knee lever to be arranged, with its longitudinal axis can also be arranged along the x-direction. The coupling the first simple lever or the first solid joint assembly to the movement unit can over a flexible, with its longitudinal axis preferably in the x direction be realized aligned web.

following 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

6 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 designed so 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 piezoactuator, the simple lever 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 forced operation 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 (that is, as seen in the y direction, spaced from the location of the opening O) F, in the present case results in a lever transmission ratio (cf. 2 ) of about 1: 4. Will thus be the first piezoelectric actuator 3a ( 2 ) is deflected by 150 microns, for example, it is due to the above-described lever approach point O between F and g1 at the right end of the lever g1 a deflection of the unit 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 5e 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 outer peripheral side.

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 to the second solid-body joint 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 exertion of force F _y on the knee lever K, 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 below the motion unit in close proximity to this and arranged to the measuring block and aligned on 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 remote 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 below it.

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 articulated solid joint assembly) mechanically via an intermediate plate with the bottom 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 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 clear distance from the ground, so hanging freely and only at its two ends on the solid state 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 his 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 6g 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. Also tilting about the x- and the y-axis is minimized thereby.

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 6b 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 previous axis has its attachment to the subsequent compensation direction (the y-direction moves everything in the x-direction with moving, 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 Finally, all three masses m _x , m _y and m _{z are} combined.

c hereby denotes the damping constants of the system in the three directions, d denotes the spring constant in the individual directions, m denotes the in the individual directions each in addition to moving masses of the system and F denotes the force and the points of attack: the knee-joint principle in the y-direction as well as 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 be able to do that the latter perform highly accurate machining processes. Examples are the mill of components, laser cutting or drilling processes. The compensation kinematics However, in general, it can be anywhere in the range of any micrometer Positioning tasks are used, including outside 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 and second, preferably also in the third spatial direction ( 2 ), at least one actuator ( 3a . 3b . 3c ), a first solid state joint assembly ( 4 ) comprising a mechanical to the movement unit ( 2 ) coupled (g1), a first simple lever (H1) forming the first solid-state hinge assembly ( 4a ), wherein by means of the at least one actuator, the first solid-state joint arrangement deflectable 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 (g2), a toggle lever (K) forming the second solid-state joint assembly ( 5a ), wherein by means of the at least one actuator, the second solid-body joint arrangement deflectable 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 are designed and arranged so that the them on 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 knee lever (K) has a two knee joints (K1, K2) exhibiting toggle lever, which preferably approximately rhomboid with the two knee joints at opposite Corners of the rhombus is formed. 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) is 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 third (g3), a second simple lever (H2) forming the third solid-body joint assembly ( 6a ), wherein by means of the at least one actuator ( 3a . 3b . 3c ) the third solid-body joint arrangement deflectable and thus due to this third coupling (g3), the movement unit ( 2 ) translationally in the third spatial direction (z) is deflectable. Ausgleichsaktorik according to the preceding claim, characterized in that the third coupling between the third solid-body hinge assembly ( 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 of the same translationally in the third spatial direction is / are deflected. 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 ), wherein preferably the first, second and third actuators are designed and arranged in such a way that the first and second actuators act on the first and second solid-state joint arrangements ( 4a . 5a ) are exerted and / or exerted two forces (F _x , F _y ) are parallel relative to each other and that the third actuator on the third solid-body joint arrangement ( 6a ) exerted and / or applied force (F _z ) is perpendicular to these two forces and preferably also in one and the same plane as these two forces 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. Compensation actuator according to 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 any one of the preceding claims, 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 such that the respective solids body steering 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 (g3), other 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 an intermediate plate connected to the movement unit on the movement 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 (g4) 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-state hinge assembly ( 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 any one of the preceding claims, 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 of the Rau te spanned surface of the toggle lever according to claim 3 and with its longitudinal axis (A2) also along the first spatial direction (x) is arranged. Ausgleichsaktorik after 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. Compensation actuator according to one of the preceding claims, characterized in that the third solid-state 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 ) is formed as part of the first solid state joint assembly. Ausgleichsaktorik after one of the preceding Claims, characterized in that at least one of the actuators, preferably all of the actuators (one) piezoactuator (s) is / are. Ausgleichsaktorik after one of the preceding Claims, characterized in that the first, the second and the third Spacing in pairs are not rectified, with preferred these three spatial directions are perpendicular to each other, so with 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. Ausgleichsaktorik base assembly comprising a compensation actuator according to any one of the preceding claims, characterized in that the Ausgleichsaktorik no actuator ( 3a . 3b . 3c ), but adapted to receive at least one such actuator 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 compensation actuator base assembly according to one of the preceding claims, characterized in that the movement unit ( 2 ) is designed as a receptacle for the object and / or as an effector, with which the workpiece 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 actuator, a compensation actuator base assembly, a device for positioning an object and / or for processing a workpiece and / or a method according to any one of the preceding claims for Positioning a component, in particular for positioning the component Component during milling, Laser cutting and / or drilling of the component.

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