Method and device for vibration isolation of a positioning device

Abstract

A device for vibration isolation of a positioning device (2), wherein the device (12) comprises a base plate (13) for the positioning device (2), at least one active bearing element (14) for supporting the base plate (13) on / at a foundation (7), and at least one evaluation and control device (15), wherein the device (12) comprises at least one means for determining a foundation movement-dependent variable, wherein the active bearing element (14) is controllable by means of the at least one control and evaluation device (15) as a function of the foundation movement-dependent variable, wherein the device (12) comprises at least one means for determining a self-motion-dependent variable of the positioning device (2), wherein the active bearing element (14) is additionally controllable by means of the at least one control and evaluation device (15) as a function of the self-motion-dependent variable of the positioning device (2), characterized in thatthat a positioning device force is determined as a variable dependent on its own movement, wherein the positioning device force is determined with a force sensor or as a function of a movement variable of a relative movement between a positioning device-side bearing section for supporting the positioning device (2) on the base plate (13) and the base plate (13), wherein the movement variable is determined with a sensor.

Description

[0001] The invention relates to a method and a device for vibration isolation of a positioning device, in particular a coordinate measuring device.

[0002] Positioning devices, such as coordinate measuring machines or robots, can be mounted on a base plate, which, due to its high mass, serves to isolate the positioning device from so-called floor vibrations. This vibration isolation allows the positioning device to be mounted as quietly as possible, which in turn enables high positioning accuracy and, in the case of a coordinate measuring device, also high measurement accuracy.

[0003] The use of vibration isolators based on a spring-mass damper principle is known. For this purpose, a bearing element for supporting the base plate on a foundation, such as a floor, can comprise a non-regulated or controlled damper element and a non-regulated or controlled spring element. These, together with the base plate, form the described spring-mass damper element. For coordinate measuring machines, it is usually desirable to tune the entire system to low frequencies, particularly in such a way that a vibration-isolating effect is achieved even at low frequencies, e.g., frequencies equal to or greater than 3 Hz.

[0004] The use of active components to decouple a machine bed from the floor is also known. EP 2 505 956 A1 describes how active components can be used to decouple a measuring machine bed from the floor.

[0005] The use of active spring elements in coordinate measuring machines is also known, as described, for example, in DE 102 29 823 A1. However, to meet the basic requirements of the pneumatic spring elements used, high base plate masses are required. This ensures that low natural frequencies are achieved.

[0006] Bearing elements are also known that generate antiphase vibration to minimize local excitations. This can also be referred to as vibration compensation. WO 2016 / 173625 A1 describes a method for dynamic compensation of dynamic effects that occur during the movement of a measuring device.

[0007] EP 2 759 735 A1 discloses a stationary vibration isolation system which is used in particular for accommodating lithography devices in the semiconductor industry, as well as a method for controlling such a vibration isolation system.

[0008] US 2007 / 0 284 794 A1 discloses an active vibration isolation system and a method for controlling an active vibration isolation system.

[0009] JP 2004-100 953 A discloses an active vibration damping device which drives an object to be controlled with an actuator in order to eliminate vibrations.

[0010] JP 2015-75 909 A discloses an active vibration isolation system for manufacturing a semiconductor manufacturing device.

[0011] EP 1 304 499 A1 discloses a precise vibration isolation device for isolating a foundation such as an installation floor for an apparatus such as a semiconductor manufacturing apparatus.

[0012] The technical problem is to create a method and a device for vibration isolation of a positioning device, in particular a coordinate measuring device, which enable a reliable isolation of the positioning device against floor vibrations with adjustable properties, wherein the weight of the device is as low as possible.

[0013] The solution to the technical problem is achieved by the subject matter having the features of the independent claims. Further advantageous embodiments of the invention are set forth in the subclaims.

[0014] A device for vibration isolation of a positioning device is proposed. The positioning device can be used to position a measuring device, for example, a sensor, in particular a sensor with a probe or an optical sensor, for generating measuring points. In this case, the positioning device can, in particular, form a coordinate measuring device or part of a coordinate measuring device. This coordinate measuring device can, for example, be designed in a so-called column or a so-called gantry design.

[0015] Alternatively, the positioning device can also be used to position a so-called end effector, such as a machining tool or a gripper. In this case, the positioning device can be designed as a robot, for example, an articulated-arm robot.

[0016] The positioning device enables the positioning of an object to be positioned, e.g. the end effector or the measuring device, in space with one or more, for example 6, degrees of freedom.

[0017] A positioning device can in particular be designed in such a way that positioning of the object to be positioned is enabled with a pulse greater than or equal to 100 mNs.

[0018] Vibration isolation refers to the isolation of the positioning device from vibrations of the floor on which the positioning device is mounted via the proposed device. This can mean that vibrations of the floor are not transmitted to the positioning device and thus to the object being positioned, or only to a reduced, i.e., dampened, extent. In the theoretically ideal case, this means that the object being positioned by the positioning device does not move when floor vibrations occur.

[0019] The device comprises a base plate for the positioning device. The positioning device can be arranged, in particular fastened or mounted, on a surface of the base plate. Accordingly, the base plate can have or form corresponding means for arrangement, for example fastening or bearing elements. The base plate can be made of a desired material, for example granite, marble, ceramic, concrete, or glass. However, it is also possible for the base plate in the proposed device to be made of a different material, for example metal, e.g. iron, steel, titanium, coated metals, e.g. metals coated with nickel or tungsten, but also non-metallic materials, e.g. plastic, in particular fiber-reinforced plastic.In particular, it is conceivable to use materials that allow for the production of good surface flatness, have a low elastic modulus, and / or a low anisotropic thermal expansion coefficient. It is also conceivable to use materials with honeycomb or foam structures.

[0020] The base plate can also form part of the positioning device.

[0021] The term "base plate" does not necessarily imply a plate-shaped base plate. Rather, the base plate can take on forms / configurations other than plate-shaped. The base plate can also be referred to as a machine bed or simply a machine bed.

[0022] The device further comprises at least one active bearing element for supporting the base plate on / at a foundation. The foundation can be a floor, for example, a ground, a floor, or another floor. The foundation can also be or comprise a wall. Thus, the base plate can also have or form means for arranging, in particular fastening and / or supporting, the at least one active bearing element. The active bearing element, in turn, can have or form means for arranging on / at the foundation.

[0023] The device preferably comprises a plurality of active bearing elements, in particular three or more than three active bearing elements. These can be arranged in different areas on the base plate, which is then supported on / at the foundation via all the bearing elements.

[0024] An active bearing element can consume energy, particularly electrical energy, during operation, which is taken from an energy source, such as an energy storage device or a power grid. A passive bearing element cannot consume such energy during operation.

[0025] An active bearing element can, in particular, refer to a controllable bearing element. This can mean that the properties of the bearing element can be adjusted using appropriate control signals.

[0026] The active bearing element can also comprise at least one actuator for generating a force and / or a movement of a movable part of the active bearing element. The actuator can comprise the movable part. This makes it possible to adjust the force to be generated or at least one movement variable of the movement to be generated, for example, a distance, a speed, or an acceleration.

[0027] The device further comprises at least one evaluation and control device. This can be designed as a computing device or comprise such a device. A computing device, in turn, can be designed as a microcontroller or integrated circuit or comprise such a microcontroller.

[0028] The device further comprises at least one means for determining a foundation movement-dependent variable. A foundation movement-dependent variable refers to a variable, particularly a physical one, that depends on or characterizes the foundation movement.

[0029] The foundation movement-dependent variable can be, for example, a foundation force, a foundation acceleration, a foundation velocity, or a position of the foundation. The foundation movement-dependent variable can, in particular, be a variable dependent on the relative movement between the foundation and the base plate.

[0030] Preferably, the foundation movement-dependent variable is the foundation acceleration. This can be measured directly or determined as a function of one of the other foundation movement-dependent variables.

[0031] The foundation force refers to a force exerted by the foundation on the device, in particular the base plate and / or a positioning device arranged on the base plate. The foundation force can refer to the force transmitted from the foundation to the base plate via the at least one active bearing element. If multiple active bearing elements are present, different foundation forces, namely bearing-element-specific foundation forces, can also be determined.

[0032] For the purposes of this invention, the term force also includes a torque, in particular about a predetermined axis of the reference coordinate system.

[0033] For the purposes of this invention, the term "determining" can refer to the detection, in particular the direct detection, of a variable. Thus, the means for determining the foundation movement-dependent variable can be a means for detecting the foundation movement-dependent variable, for example, a force, acceleration, speed, or position sensor. Piezoelectric sensors or MEMS-based sensors, in particular, can be used as acceleration sensors. However, the term "determining" also refers to the exclusively or at least partially computational determination of a desired variable. Thus, the variable to be determined can, for example, be determined as a function of at least one variable different from the variable to be determined, for example, via previously known relationships, in particular functional relationships or assignments.The at least one different quantity can in turn be recorded, in particular recorded directly, or also determined mathematically.

[0034] Thus, a model-based determination of the foundation movement-dependent variable is also possible, whereby a model, for example, describes a relationship between at least one input variable different from the foundation movement-dependent variable and the foundation movement-dependent variable to be determined.

[0035] The foundation movement-dependent quantity can also be determined as a movement quantity of a foundation movement or base plate movement, whereby the movement quantity can be recorded, for example.

[0036] It is possible, for example, to record / determine the foundation movement-dependent variable as a foundation acceleration or as a function of the foundation acceleration and / or an acceleration of the base plate, for example using an acceleration sensor. Alternatively, it is possible to record a foundation speed or a speed of the base plate, for example using a speed sensor, and then determine the foundation movement-dependent variable as a function of the foundation speed or as a foundation speed. Further alternatively, it is possible to determine a foundation path, i.e. a path traveled by the foundation, and then determine the foundation movement-dependent variable as a function of or as this path. It is also possible, for example, to determine the foundation acceleration as a function of the foundation speed or the foundation path, for example using suitable derivatives.

[0037] The foundation force or a movement variable of a foundation movement can be determined in a reference coordinate system, for example, a global coordinate system. The global coordinate system can, in particular, be a GNSS-based coordinate system.

[0038] The foundation movement-dependent variable can be determined directly at the foundation, in particular at a mechanical interface between the foundation and the active bearing element, or based on a variable determined there. The foundation movement-dependent variable can also be determined based on a variable determined on / in the base plate or on / in the positioning device. In this case, in particular, a model-based determination can be performed, with the model used for the determination comprising a dynamic model of the device and, if applicable, other components.

[0039] Furthermore, the active bearing element can be controlled by means of the at least one control and evaluation device depending on the foundation movement-dependent variable. For example, the control and evaluation device can generate a control signal for the at least one active bearing element depending on the foundation movement-dependent variable. In particular, the at least one control and evaluation device can control the active bearing element depending on the foundation movement-dependent variable such that it generates a force dependent on this variable and / or sets a movement variable dependent on this variable. In this case, in particular the direction and / or the magnitude of the force to be generated by the active bearing element and / or the direction and / or the magnitude of at least one movement variable of the movement to be generated by the active bearing element can be set.

[0040] For this purpose, control or regulation methods known to those skilled in the art can be used. Thus, the active bearing element can be controlled depending on the foundation movement-dependent variable, in particular, using known control or regulation methods.

[0041] By controlling the active bearing element, in particular by adjusting the force to be generated and / or the movement magnitude to be generated, a natural frequency and a damping behavior of the active bearing element can be set, in particular to a target stiffness, which can be predetermined, for example. This in turn can influence the vibration transmission behavior of the active bearing element and adjust it as desired. For example, the stiffness of the bearing element can be adjusted such that the bearing element has a desired cutoff frequency. It can also be made possible, for example, for the active bearing element to have a desired low-pass, high-pass or band-pass behavior when transmitting vibrations from the foundation to the base plate. Preferably, the active bearing element is controlled such that the transmission behavior has a high-pass behavior with a cutoff frequency in the range of 0.1 Hz to 1.0 kHz.The transmission behavior can also be a band-stop behavior with cutoff frequencies from the mentioned range.

[0042] Thus, the control system can influence the transmission behavior in such a way that foundation vibrations are not transmitted to the base plate and thus also to the positioning device, or are transmitted only to a reduced extent. This, in turn, advantageously enables reliable vibration isolation. Vibration isolation means that vibrations are not transmitted from the foundation to the base plate, or are transmitted to a reduced extent, due to the transmission behavior of the active bearing element.

[0043] In addition, vibration compensation can also be advantageously enabled. In this case, the active bearing element can, in particular, be controlled in such a way that a vibration that is in phase opposition to the foundation vibration is generated. This can mean that a movable part of the active bearing element moves in such a way that, despite the foundation movement, the base plate is stationary in the previously explained reference coordinate system. In this case, for example, the movement variables of the movable part of the actuator of the active bearing element can be adjusted in such a way that the movable part of the active element executes a movement with the same frequency and the same amplitude as the foundation, with the direction of movement being adjusted in such a way that the previously explained stationary arrangement of the base plate is achieved. This advantageously results in further improved robustness of the vibration damping.

[0044] This, in turn, advantageously results in a reduction in the weight of the base plate, as the requirements for vibration isolation properties are also reduced. If the base plate is part of the positioning device, the weight of the positioning device can also be reduced.

[0045] In a further embodiment, the active bearing element additionally comprises a spring element, in particular a passive spring element. Alternatively or cumulatively, the active bearing element additionally comprises at least one damper element, in particular a passive damper element. A spring element can have predetermined spring properties, in particular a predetermined spring stiffness. A damper element can have a predetermined, in particular constant, damping constant.

[0046] The spring element and / or the damper element, as well as the actuator of the active bearing element, can be arranged mechanically in parallel. However, other mechanical arrangements, in particular a mechanical series connection or a combination of series and parallel connections, of these elements are also conceivable.

[0047] By providing an additional spring element and / or an additional damper element, a static load can advantageously be absorbed by the base plate and, if applicable, the positioning device of the active bearing element without energy being consumed during the static absorption. By providing an additional damper element, a vibration transmission behavior of the bearing element can advantageously be adjusted in the non-activated state of the active bearing element, i.e., a state without energy consumption. Furthermore, it advantageously results that the additional mechanical damping by the spring element and / or the damper element has to meet lower requirements than in a design without an active bearing element, which advantageously allows savings in installation space and manufacturing costs for the spring and / or damper element.

[0048] In a further embodiment, the device comprises at least one means for determining or detecting a base plate movement-dependent variable.

[0049] The base plate movement-dependent quantity refers to a quantity, in particular a physical one, that depends on or characterizes the movement of the base plate.

[0050] The baseplate movement-dependent variable can be, for example, a baseplate force, a baseplate acceleration, a baseplate velocity, or a position of the baseplates. The baseplate movement-dependent variable can, in particular, be a variable dependent on the relative movement between the baseplate and the foundation.

[0051] The baseplate force can refer to a force acting from the baseplate via the active bearing element onto the foundation. In accordance with the previous explanations regarding the means for determining the foundation movement-dependent variable, the means for determining the baseplate movement-dependent variable can also be implemented in various forms. For example, the baseplate force can be determined as a function of a movement variable of the baseplate movement, whereby the movement variable can be recorded or also determined. One of the aforementioned baseplate movement-dependent variables can also be determined as a function of another, different baseplate movement-dependent variable.

[0052] According to the invention, the device comprises at least one means for determining a self-motion-dependent variable of the positioning device. The self-motion-dependent variable of the positioning device refers to a, in particular physical, variable that depends on the self-motion of the positioning device, e.g., is caused by it, or characterizes it.

[0053] The self-motion-dependent variable is a positioning device force generated during the movement of a movable part of the positioning device. It is also described that this variable can be an acceleration, a velocity, or a position of a movable part of the positioning device during a self-motion of the positioning device, which will be explained in more detail below. The self-motion-dependent variable can, in particular, be a variable dependent on the relative movement between the positioning device and the base plate.

[0054] The positioning device force refers to a force that is transmitted from the positioning device via the base plate and the active bearing element to the foundation, and thus also via the active bearing element. This positioning device force can lead to disruptive movements if vibration isolation is not sufficiently isolating or compensating in the corresponding frequency range.

[0055] The positioning device force can refer to the total of a (static) weight force and a dynamic force of the positioning device, or exclusively to the dynamic force transmitted from the positioning device to the foundation via the base plate and the active bearing element. A dynamic force refers to a force resulting from the inherent movement of the positioning device.

[0056] In accordance with the previous explanations regarding the design of a means for determining the foundation movement-dependent variable, the means for determining the self-motion-dependent variable can also be implemented in various embodiments. For example, the self-motion-dependent variable can be determined as one of the aforementioned self-motion-dependent variables or as a function of another, different self-motion-dependent variable of the positioning device's own movement, which can be detected or also determined.

[0057] The positioning device force can refer to a force different from the weight of the positioning device. In particular, the positioning device force can be generated by the positioning device's own movement. The own movement refers to a movement generated by at least one drive device of the positioning device. This drive device is different from the active bearing element. The own movement can be a movement of a movable part of the positioning device, e.g., a joint or the object to be positioned. The magnitude of the base plate movement and the own movement of the positioning device can be determined in the reference coordinate system explained.

[0058] Furthermore, the active bearing element can be controlled by means of the at least one control and evaluation device additionally as a function of the base plate movement-dependent variable and / or the self-movement-dependent variable of the positioning device.

[0059] The self-motion-dependent variable can be detected directly, e.g., with a sensor, or determined, e.g., model-based. The control and evaluation device can be connected via data and / or signal technology to at least one means for determining the motion variable.

[0060] For example, the previously explained positioning device force and / or the previously explained base plate movement-dependent variable can be determined depending on the determined self-motion-dependent variable. The active bearing element can then be controlled in such a way that the base plate force and / or the force transmitted from the positioning device via the base plate to the active bearing element and / or the positioning device force are compensated. In particular, the force exerted by the active bearing element on the base plate can thus compensate for the positioning device force.

[0061] It is also possible to determine at least one movement quantity of the base plate, e.g. depending on the base plate movement-dependent quantity and / or the self-movement-dependent quantity, and to control the active bearing element in such a way that the actual movement of the base plate is prevented or reduced to a desired level.

[0062] In other words, a movement of the base plate caused by the movement of the positioning device, in particular of an object to be positioned, can be determined. The active bearing element, in particular a movable part of the active bearing element, can then be controlled in such a way that this movement of the base plate induced by the positioning device is reduced or eliminated.

[0063] This advantageously results in the fact that vibrations of the base plate induced by the positioning device's own movement can be reliably eliminated or reduced. This, in turn, advantageously improves the positioning and measurement accuracy of the positioning device.

[0064] In other words, the effects of the positioning device's own movement on the position and / or orientation of the base plate can be reduced. Especially with low base plate masses, the positioning device's own movement can cause undesirable movements of the base plate, especially at frequencies in the range of the resonant frequency of the resulting mechanical system. This effect can be advantageously avoided by the proposed control of the active bearing element.

[0065] In a preferred embodiment, the self-motion-dependent variable is determined based on a model. The model can, in particular, be a relationship between a movement variable of the positioning device, in particular a movement variable of the object to be positioned, and the previously explained positioning device force. The model can also be a relationship between control signals for adjusting a movement variable of the self-motion of the positioning device and the positioning device force.

[0066] The at least one movement variable can be determined or detected. Thus, depending on an actual movement of the positioning device or a desired movement of the positioning device, the movement-dependent variable, in particular the positioning device force, can be determined, and the at least one active bearing element can be controlled accordingly.

[0067] Of course, the model can also describe a relationship between additional properties of the positioning device and / or the object to be positioned, e.g., a weight. In this case, the positioning device force can also be determined depending on these properties.

[0068] This advantageously enables the use of low-mass base plates, reducing the installation space and manufacturing costs for the device.

[0069] In a further embodiment, the maximum force that can be generated by the active bearing element is greater than 100 N. This advantageously results in the fact that high foundation forces and / or positioning device forces and thus also the resulting movement of the base plate can be compensated for, thus enabling, for example, high accelerations of the positioning device. Furthermore, the higher the maximum force that can be generated, the higher the upper limit frequency of the vibration isolation and compensation, and in the proposed embodiment, the desired vibration isolation and compensation is thus possible. Alternatively or cumulatively, the dynamics of the active bearing element are greater than 50 Hz, in particular greater than 100 Hz. The dynamics can refer to the frequency with which a movable element of the active bearing element can be moved with a predetermined amplitude, for example of 30 µm.This advantageously results in floor vibrations and, if applicable, movements of the base plate caused by the inherent movement of the positioning device being able to be reliably isolated or compensated.

[0070] Further alternatively or cumulatively, a damping provided by the active bearing element is greater than 50% for frequencies less than 10 Hz. The active bearing element can therefore be designed, arranged and / or controlled in such a way that an amplitude of the movement of the base plate caused by the foundation vibration with a frequency less than 10 Hz with the active bearing element is more than 50% lower than without the active bearing element, in particular with a rigid coupling of foundation and base plate.

[0071] In a preferred embodiment, the active bearing element comprises a piezo actuator. This advantageously results in a reliable and cost-effective design of the proposed device. Alternatively, the active bearing element comprises an electromagnetic actuator. Further alternatively, the active bearing element comprises a capacitive actuator. This also advantageously results in a simple and cost-effective design of the actuator.

[0072] Furthermore, it is possible that the set of bearing elements by which the base plate is mounted on the foundation does not include an air bearing element.

[0073] In a further embodiment, the active bearing element comprises at least one position detection device. The position detection device can be used to detect, in particular, the current position of a movable part of the active bearing element, in particular the actuator. Such a position detection device can be used to determine, in addition to the inherent movement caused by the actuator of the active bearing element, an externally induced movement of the movable part, for example, a movement of the movable part caused by floor vibrations or base plate movements. This advantageously enables the detection of current vibrations in the system, in particular so-called residual vibrations.

[0074] Furthermore, it is possible to control the active bearing element depending on the position or position change detected by the position detection device of the active bearing element, in particular to reduce or eliminate the residual vibrations described above. This advantageously results in a further improved reduction of vibrations and thus, consequently, also in improved positioning and measurement accuracy.

[0075] In a further embodiment, the device comprises at least three active bearing elements. This has already been explained above. This advantageously results in torsional vibrations, particularly those caused by the inherent movement of the positioning device or movements of the base plate, being eliminated or at least reduced through appropriately controlled or regulated operation of the at least three active bearing elements.

[0076] Furthermore, it is possible for the proposed device to comprise a plurality of active bearing elements, which are designed and / or arranged in such a way that undesired movements, in particular vibrations of the base plate (and thus of the positioning device), can be reduced or eliminated exclusively along or parallel to precisely one spatial direction or along or parallel to several, in particular two or three linearly independent spatial directions. For example, it is possible for the previously explained reference coordinate system to be a Cartesian coordinate system, with a vertical axis (z-axis) oriented parallel and opposite to a direction of a gravitational force. A longitudinal axis and a transverse axis (x-axis, y-axis) can then span a plane oriented perpendicular to the vertical axis.In this case, the at least one active bearing element can be arranged and / or configured such that only undesired movements / vibrations along exactly one of the axes mentioned, in particular along the vertical axis, can be reduced or eliminated. However, it is also possible for multiple active bearing elements to be arranged and / or configured such that undesired movements / vibrations along exactly two or exactly the axes explained can be reduced or eliminated. Furthermore, it is possible for the active bearing elements to be arranged and / or configured such that undesired rotational movements / rotational vibrations about exactly one of the axes explained, in particular about the vertical axis, or about exactly two or exactly three of the axes explained can be reduced or eliminated.

[0077] This advantageously results in a reliable and improved stabilization of the position of the base plate.

[0078] If the device comprises several active bearing elements, a bearing-element-specific determination of the foundation movement-dependent variable can be carried out. This means that the foundation movement-dependent variable transmitted to the base plate via the specific active bearing element is determined. Similarly, a bearing-element-specific determination of a base plate movement-dependent variable and / or an inherent movement-dependent variable of the positioning device can be carried out. A bearing-element-specific determination of a movement variable of the foundation, the base plate, and / or the positioning device can also be carried out. This can mean that the movement variable of a movement of a section on which the active bearing element is arranged is determined. The active bearing element can then be controlled depending on these bearing-element-specific variables.

[0079] Further proposed is an arrangement comprising a positioning device and a vibration isolation device according to one of the embodiments described in this disclosure. The positioning device is mounted on or on the base plate of the device.

[0080] Further described is a method for vibration isolation of a positioning device using a vibration isolation device according to one of the embodiments described in this disclosure. A foundation movement-dependent variable is determined. Furthermore, the active bearing element is controlled depending on the foundation movement-dependent variable. Thus, the device described in this disclosure is configured such that the described method can be carried out using the device.

[0081] In particular, the active bearing element, in particular an actuator of the active bearing element, can be controlled in such a way that a movement of the base plate (and thus also of the positioning device) caused by the foundation movement-dependent variable is reduced or completely eliminated. It is also possible to control the active bearing element depending on a movement variable of a foundation movement.

[0082] As explained above, it is also possible for the active bearing element to be additionally controlled as a function of a base plate movement-dependent variable and / or as a function of a movement variable of the base plate movement and / or as a function of a movement variable of the inherent movement of the positioning device and / or as a function of a position detected by a position detection device of the active bearing element. In particular, the active bearing element can then be controlled such that undesired movements, in particular vibrations, are reduced or completely eliminated. According to the invention, the active bearing element is additionally controlled as a function of the inherent movement-dependent variable, wherein it can in particular be controlled such that a movement of the base plate caused by the inherent movement of the positioning device is reduced or completely eliminated.

[0083] The invention is explained in more detail using exemplary embodiments. The figures show: Fig. 1 is a schematic view of a vibration isolation device with a positioning device according to the prior art; Fig. 2 a schematic view of a device according to the invention with a positioning device; Fig. 3 a schematic view of a device according to the invention with a positioning device according to a further embodiment of the invention; Fig. 4 a schematic view of a device according to the invention with a positioning device according to a further embodiment of the invention; Fig. 5 a schematic view of a device according to the invention with a positioning device according to a further embodiment of the invention; Fig. 6 a schematic view of a device according to the invention with a positioning device according to a further embodiment of the invention; Fig. 7 a schematic side view of a device according to the invention with a positioning device according to a further embodiment of the invention; and Fig. 8 a schematic flow diagram of a method according to the invention.

[0084] In the following, the same reference symbols designate elements with the same or similar technical features.

[0085] Fig. 1 shows a device 1 for vibration isolation of a positioning device designed as a coordinate measuring device 2 according to the prior art. This device 1 comprises a base plate 3, which can be designed, for example, as a granite slab. The device 1 further comprises passive damper elements 4 and passive spring elements 5, which are arranged mechanically parallel to one another. A first damper element 4a and a first spring element 5a form a first passive bearing element 6a. Correspondingly, a second damper element 4b and a second spring element 5b form a second passive bearing element 6b, wherein the base plate 3 is mechanically connected to a foundation 7 via the bearing elements 6a, 6b. In particular, the base plate 3 is mounted on the foundation 7 via the bearing elements 6a, 6b. A reference coordinate system with a vertical axis z and a transverse axis y is shown.Not shown is a longitudinal axis x, which is oriented at right angles to the vertical axis z and the transverse axis y. The vertical axis z is oriented parallel and opposite to the direction of a gravitational force. The coordinate measuring device 2 is a gantry-type coordinate measuring device 2, wherein movable parts of this positioning device 2 serve to spatially position a measuring device 8, which is attached to a sleeve 9 of the coordinate measuring device 2. The measuring device 8 can comprise an optical or tactile sensor for generating measuring points for measuring a measurement object. Also shown is a traverse 10, wherein the sleeve 9 can be moved along the transverse direction y along the traverse 10. Furthermore, the measuring device 8 can be moved along the sleeve 9 along the vertical direction in order to position the measuring device 8.Stand elements 11 on which the cross member 10 is mounted can be moved along the longitudinal direction not shown.

[0086] A proper movement of this positioning device can thus comprise a movement of these moving parts along the spatial axes explained.

[0087] Fig. Figure 2 shows a device 12 according to the invention with a positioning device designed as a coordinate measuring device 2. The coordinate measuring device 2 is like the one shown in Fig. 1 shown coordinate measuring device 2. Therefore, reference is made to the corresponding explanations Fig. 1. The device 12 comprises a base plate 13. This can be made of a granite slab, for example. However, this is not mandatory. It is also conceivable, for example, to use a lighter material than granite to form the base plate 13, for example metal or plastic. The device 12 also comprises active bearing elements 14, wherein the base plate 13 is mounted on a foundation 7 via these active bearing elements 14. An active bearing element 14 can comprise an actuator 17, in particular a piezo actuator. The actuator 17, in turn, can comprise at least one movable part. In this case, it is possible for a desired output force from the actuator 17 and / or a desired movement of the movable part of the actuator 17 to be set, e.g. by controlling the actuator using corresponding control signals.This can be done by means of a control and evaluation device 15 of the device 12 according to the invention, which can control the active bearing elements 14 and thus also their actuators 17 accordingly. Furthermore, the device 12 comprises means designed as acceleration sensors 16 for determining a foundation movement-dependent variable, namely a foundation acceleration. A foundation force acts due to the foundation acceleration, wherein the foundation force refers to the force transmitted from the foundation 7 via the active bearing elements 14 to the base plate 13. The design of the means for determining the foundation force as acceleration sensors 16 is exemplary here. The means for determining the foundation movement-dependent variable can also comprise means for determining or detecting the foundation force or another movement variable of a foundation movement, for example a displacement sensor, speed sensor, or force sensor.Furthermore, the means for determining the foundation movement-dependent variable can then comprise an evaluation device for determining the foundation movement-dependent variable as a function of the movement variable. This can be formed, for example, by the control and evaluation device 15.

[0088] The means for determining the foundation movement-dependent variable or an explained sensor can be arranged at a foundation-side end of the active bearing element 14, in particular if the means is designed as an acceleration sensor or comprises such an acceleration sensor.

[0089] However, it is also possible for the means for determining the foundation movement-dependent variable to be arranged elsewhere, e.g., at a baseplate-side end of the active bearing element 14, particularly if the means is designed as a force sensor or comprises such a sensor. It is also possible for the means to be arranged on the positioning device or on the measuring device. In this case, the foundation movement-dependent variable can be determined, in particular, using a model, e.g., a mechanical or dynamic model, of the positioning device.

[0090] In particular, the control and evaluation device 15 can be connected to the active position elements 14 and to the force sensors 16 via data and / or signal technology.

[0091] By means of the control and evaluation device 15, the active bearing elements 14 can be controlled depending on the determined foundation movement-dependent variable. In particular, a force of the actuator and / or at least one movement variable of a movement of the movable part of the actuator 17 can be adjusted by the control and evaluation device 15.

[0092] In particular, the output force of the actuator 17 of the active bearing element 14 and / or the at least one movement quantity of the movement of the movable part can be adjusted such that movement of the base plate 13 caused by a movement of the foundation 7 is reduced or completely eliminated.

[0093] It is also possible for the active bearing elements 14 to be controlled by means of the control and evaluation device 15 as a function of a movement variable of the foundation movement, in particular in such a way that the movement of the base plate 7 caused by the foundation movement is reduced or completely eliminated.

[0094] Fig. 3 shows a schematic view of a device 12 according to the invention in a further embodiment with a positioning device 2, which is arranged in accordance with the Fig. 1 illustrated embodiment of the positioning device 2. In contrast to the embodiment shown in Fig. In the embodiment of the device 12 shown in Figure 2, an active bearing element 14 comprises, in addition to the actuator 17, a (passive) spring element 5, which is arranged mechanically parallel to the actuator 17 of the corresponding active bearing element 14. In particular, the base plate 13 is mounted on the foundation 7 via active bearing elements 14, which comprise spring elements 5 and actuators 17 arranged mechanically parallel.

[0095] Fig. 4 shows a device 12 according to the invention for vibration isolation in a further embodiment with a positioning device 2, which is arranged according to the Fig. 1. In contrast to the embodiment shown in Fig. In the embodiment of the device 12 shown in Figure 2, the device 12 comprises means designed as force sensors 18 for detecting a positioning device force, wherein the positioning device force refers to a force exerted or transmitted by the positioning device 2 onto the base plate 13. In particular, the positioning device force refers to a force generated by an inherent movement of the positioning device 2, which force acts on the base plate 13. This inherent movement refers to a movement of a movable part of the positioning device 2 or a movement of an object to be positioned, e.g., the previously explained measuring device 8.

[0096] The design of the means for determining a positioning device force as force sensors 18 is purely exemplary. Of course, it is also possible to determine the positioning device force in another way. For example, the positioning device force can be determined as a function of at least one movement variable of a movement of a movable part of the positioning device 2, for example a movement of the measuring device 8. For example, such a movement variable can be detected, e.g., with a sensor. It is also possible to determine such a movement variable, in particular mathematically. Furthermore, the positioning device force can then be determined as a function of a predetermined relationship between the at least one movement variable and the positioning device force. This relationship can, in particular, be model-based.

[0097] In Fig. 4 shows that the force sensor 19 is arranged between a support base 19 and a surface of the base plate 13. It is also possible to arrange a means, in particular a sensor, for determining a movement variable of a relative movement between the support bases 19 of the positioning device 2 and the base plate 13 there, and then to determine the positioning device force as a function of this movement variable. If the support bases 19 are, for example, air-bearing mounted on the base plate 13, the sensor can be or comprise, for example, an air pressure sensor or distance sensor for detecting the width of the air gap, wherein the positioning device force can be determined as a function of the air pressure or the width.

[0098] More generally, a movement quantity of a relative movement between the positioning device-side bearing section for supporting the positioning device 2 on the base plate 13 and the base plate 13 can be determined, wherein the positioning device force is then determined as a function of this relative movement.

[0099] The positioning device force forms a self-motion-dependent variable of the self-motion of the positioning device 2. In general, it is also possible for the device 12 to comprise means for detecting a self-motion-dependent variable, which can be, for example, a positioning device acceleration, speed or distance / position.

[0100] Then, as previously explained, the active bearing elements 14 can be controlled depending on the positioning device force or the explained inherent motion-dependent variable. Alternatively, it is also possible to control the active bearing elements 14 depending on a movement variable of the explained relative movement or the inherent motion of the positioning device 2 or the base plate 13.

[0101] Fig. 5 shows a schematic view of a device 12 according to the invention according to a further embodiment with a positioning device 2 which is arranged in accordance with the Fig. 1. In contrast to the positioning device 2 shown in Fig. In the device 12 shown in Figure 3, an active bearing element 14 comprises, in addition to an actuator 17 and a passive spring element 5, a passive damper element 4 which is arranged mechanically parallel to the actuator 17.

[0102] Fig. 6 shows a schematic representation of a device 12 according to the invention, in a further embodiment with a positioning device 2, which is arranged according to the Fig. 1 illustrated embodiment.

[0103] Here, it is shown that the base plate 13 is mounted on / at a foundation 7 via a plurality of active bearing elements 14. In particular, an underside of the base plate 13 is mounted on the foundation 7 via active bearing elements 14. The positioning device 2 is mounted on an upper side of the base plate. Furthermore, side surfaces, i.e., longitudinal and transverse sides, of the base plate 13 are mounted on the foundation 7 via further active bearing elements 14. This enables the reduction or complete elimination of movements of the base plate 13, even along spatial axes that differ from the vertical axis z, in particular along the longitudinal axis and / or the transverse axis y. Undesired rotational movements of the base plate 13, which are caused by the inherent movement of the positioning device 2 and / or by the foundation movement, can also be reduced.

[0104] Fig. Figure 7 shows a schematic representation of a device 12 according to the invention in a further embodiment. In contrast to the device 12 shown in Fig. In the embodiment shown in Figure 3, the positioning device 2 is not designed as a coordinate measuring device, but as a robot 20, in particular as a so-called articulated arm robot.

[0105] Fig. 8 shows a schematic flow diagram of a method according to the invention for vibration isolation by means of one of the Fig. 2 to Fig. 7. In a first step S1, a foundation movement-dependent variable is determined, for example by means of the Fig.2 or other means for determining the foundation movement-dependent variable. Furthermore, in a second step S2, an active bearing element 14 is controlled, in particular by means of the control and evaluation device 15, as a function of the foundation movement-dependent variable, in particular such that the movement of the base plate 13 caused by a foundation movement is reduced or eliminated. List of reference symbols 1 Device for vibration isolation according to the state of the art 2 Positioning device, coordinate measuring device 3 Base plate 4, 4a, 4b passive damper element 5, 5a, 5b passive spring element 6a, 6b bearing element 7 Foundation 8 Sensor 9 quill 10 traverse 11 stands 12 Vibration isolation device 13 Base plate 14 active bearing element 15 Control and evaluation device 16 Accelerometer 17 Actuator 18 force sensor 19 storage section 20 articulated arm robots S1 first step S2 second step z vertical axis y transverse axis

Claims

[1] A device for vibration isolation of a positioning device (2), wherein the device (12) comprises a base plate (13) for the positioning device (2), at least one active bearing element (14) for supporting the base plate (13) on / at a foundation (7), and at least one evaluation and control device (15), wherein the device (12) comprises at least one means for determining a foundation movement-dependent variable, wherein the active bearing element (14) is controllable by means of the at least one control and evaluation device (15) as a function of the foundation movement-dependent variable, wherein the device (12) comprises at least one means for determining a self-motion-dependent variable of the positioning device (2), wherein the active bearing element (14) is additionally controllable by means of the at least one control and evaluation device (15) as a function of the self-motion-dependent variable of the positioning device (2), characterized bythat a positioning device force is determined as a variable dependent on its own movement, wherein the positioning device force is determined with a force sensor or as a function of a movement variable of a relative movement between a positioning device-side bearing section for supporting the positioning device (2) on the base plate (13) and the base plate (13), wherein the movement variable is determined with a sensor. [2] Device according to claim 1, characterized by that the active bearing element (14) additionally comprises a spring element (5) and / or a damper element (4). [3] Device according to one of the preceding claims, characterized by that the device (12) comprises at least one means for determining a base plate movement-dependent variable, wherein the active bearing element (14) can additionally be controlled by means of the at least one control and evaluation device (15) as a function of the base plate movement-dependent variable. [4] Device according to claim 3, characterized by that the self-motion-dependent size of the positioning device (2) can be determined on a model-based basis. [5] Device according to one of the preceding claims, characterized by that a maximum force that can be generated by the active bearing element (14) is greater than 100 N and / or a dynamic range is greater than 50 Hz and / or a damping provided by the active bearing element is greater than 50% for frequencies less than 10 Hz. [6] Device according to one of the preceding claims, characterized by that the active bearing element (14) comprises a piezo actuator or an electromagnetic actuator or a capacitive actuator. [7] Device according to one of the preceding claims, characterized by that the active bearing element (14) can be additionally controlled by means of the at least one control and evaluation device (15) as a function of at least one movement variable of the positioning device (12). [8] Device according to one of the preceding claims, characterized by that the active bearing element (14) comprises at least one position detection device. [9] Device according to one of the preceding claims, characterized by that the device comprises at least three active bearing elements (14). [10] Arrangement comprising a positioning device (2) and a device (12) according to one of claims 1 to 9, wherein the positioning device (2) is mounted on or at the base plate (13) of the device (12). [11] Method for vibration isolation of a positioning device (2) by means of a device (12) according to one of claims 1 to 9, wherein a foundation movement-dependent variable and a self-movement-dependent variable are determined, wherein the active bearing element (14) is controlled as a function of the foundation movement-dependent variable and additionally as a function of the self-movement-dependent variable, characterized bythat a positioning device force is determined as a variable dependent on its own movement, wherein the positioning device force is determined with a force sensor or as a function of a movement variable of a relative movement between a positioning device-side bearing section for supporting the positioning device (2) on the base plate (13) and the base plate (13), wherein the movement variable is determined with a sensor.

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