Parallel kinematic movement device

Abstract

The invention relates to a parallel kinematic movement device (1) comprising a platform (2) which can be moved in at least six degrees of freedom, wherein the platform is supported by at least three leg elements (3); the end section (32) of each leg element (3) facing the platform (2) is coupled to the platform (2) via a first joint (40); and the end section (34) of each leg element (3) facing away from the platform (2) is coupled to a dedicated adjusting element (50) of the respective leg element (3) via a second joint (42), said adjusting element being movable about a first rotational axis (RA1) and a second rotational axis (RA2) that differs from the first rotational axis (RA1). A respective first drive element (60) and a respective second drive element (62) are arranged on at least one of the adjusting elements (50), in each case so as to engage directly on the adjusting element, in order to implement independent rotational or tilting movements of the adjusting element (50) about the first rotational axis (RA1) and about the second rotational axis (RA2) such that the drive movements of the first drive element (60) and of the second drive element (62) can be transmitted directly to the at least one adjusting element (50) independently of one another, and by virtue of corresponding rotational or tilting movements of the at least one adjusting element (50), an adjusting movement of the associated leg element (3) can be produced.

Description

Parallel kinematic movement device

[0001] The invention relates to a parallel kinematic movement device according to claim 1.

[0002] For example, a parallel kinematic motion device in the form of a tripod is known from the prior art. A platform to be moved or positioned is supported by three fixed-length leg elements, each of whose foot sections facing away from the platform is moved in two degrees of freedom. In this context, this is also referred to as a foot-point movement of the leg element. The movements along or around the two degrees of freedom of this foot-point movement are achieved by stacked or superimposed drives.

[0003] A disadvantage of such a parallel kinematic motion device is the fact that the lower drive of the stacked drives, which is responsible for movement with respect to one of the two degrees of freedom, must support both the weight of the drive arranged above it, which is responsible for movement with respect to the other of the two degrees of freedom, as well as the respective weight of the leg element and the weight of the payload to be carried by the leg element. In addition, there are forces, in particular restoring forces, that act on the lower drive due to the movement of the supply cables of the drive located above it. Another disadvantage is the space-consuming geometry of the drives of such parallel kinematic motion devices known from the prior art.

[0004] Therefore, it is an object of the invention to provide a parallel kinematic movement device in which parasitic forces such as restoring forces caused by supply cables are reduced or eliminated and in which the forces acting on the drives are distributed more evenly, and this with a small space requirement of the drives.

[0005] This object is achieved by a parallel kinematic movement device according to claim 1, wherein the subclaims contain at least expedient further developments.

[0006] Essential to the invention is the combination of the two drives or their corresponding drive axes into a common drive unit in the form of an actuator with drive elements directly engaging it. This eliminates the additional loads caused by the supply cables and the weight of the second drive axis in prior art parallel kinematic devices. Furthermore, the invention allows for a significantly more compact design of a corresponding parallel kinematic motion device.

[0007] For driving or moving the actuating element about two different axes of rotation RA1, RA2, the use of at least two drive elements, for example in the form of linear actuators or linear motors, but also in the form of rotary drives, is advantageous. It is conceivable and can be advantageous to use more than two drive elements to move an actuating element. The drive elements can be implemented, for example, by electromagnetic direct drives or voice coil drives, which advantageously have an air bearing. When using electromagnetic direct drives in combination with an air bearing, it is particularly advantageous to provide a pressure chamber into which compressed air from the air bearing can be fed in order to compensate for force or weight and thus maintain a position of the drive element without applying current to it.

[0008] However, drive elements based on a pneumatic or hydraulic operating principle are also conceivable. Drives based on the principle of shape-changing materials, for example, through the action of thermal or electrical energy, are also conceivable.

[0009] The parallel kinematic motion device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that at least one of the actuating elements is cardanically mounted. A cardanic bearing enables the realization of two rotational degrees of freedom with respect to different axes of rotation in a comparatively simple manner, and corresponding elements for implementing such cardanic bearings are inexpensive and available on the market in a wide variety of designs. It can be particularly advantageous to implement the cardanic bearing using flexure joints. However, the realization of the cardanic bearing using rotary bearings such as ball bearings, roller bearings, or needle bearings is also conceivable.

[0010] The parallel kinematic movement device according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that each of the actuating elements is part of a respective adjustment unit which, in addition to the actuating element, comprises a base element and a carrier element, wherein the base element is mounted in a rotationally fixed manner, and the carrier element is mounted on the base element in such a way that it can perform a rotational or tilting movement about the first axis of rotation, and the actuating element is mounted on the carrier element in such a way that it can perform a rotational or tilting movement about the second axis of rotation.

[0011] The parallel kinematic movement device according to the invention can be used with otherwise any other feature provided according to the invention of a combination of features described herein may be implemented in such a way that the mounting of the support element on the base element or the mounting of the adjusting element on the support element is implemented by an articulated connection.

[0012] The parallel kinematic movement device according to the invention can be realized with any other feature provided according to the invention of a combination of features described herein in such a way that the articulated connection is realized by a solid-body joint, preferably by a cross-spring pivot joint.

[0013] The parallel kinematic movement device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that the base element and the support element, and optionally the adjusting element, have a frame-shaped geometry. It can be particularly advantageous if the base element, the support element, and the adjusting element are arranged nested within one another. This allows for a particularly space-saving and lightweight design of a corresponding adjustment unit.

[0014] The parallel kinematic movement device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that at least one of the drive elements is designed as a linear drive or as a rotary drive. In this case, it can be particularly advantageous if the at least one drive element is designed as a direct drive and, in particular, as a voice coil drive.

[0015] The parallel kinematic movement device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that at least one of the leg elements is designed or mounted such that it has four degrees of freedom, one of which is a shear degree of freedom and the remaining degrees of freedom are angular degrees of freedom. It can be particularly advantageous if the shear degree of freedom of the at least one leg element is implemented by a third joint arranged between its two opposite end sections.

[0016] The parallel kinematic movement device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that each of the leg elements is assigned its own separate adjustment unit. This allows, in particular, a modular design or a modular production of the parallel kinematic movement device.

[0017] The parallel kinematic movement device according to the invention can be implemented with any other feature provided according to the invention of a combination of features described herein in such a way that it has a device for acquiring and processing measurement or operating data relevant to the state of the parallel kinematic movement device, which device is designed to concurrently acquire and process the measurement or operating data during the running or operating time of the parallel kinematic movement device and optionally link them together so that an image of the state of the parallel kinematic movement device can be derived therefrom. In this case, it is particularly advantageous to be able to detect an impending failure or wear of the parallel kinematic movement device or a component thereof at an early stage from the image of the state and to initiate appropriate countermeasures.It is conceivable that the measurement or operating data are automatically transmitted via the Internet to a maintenance or service center, where the measurement or operating data are monitored and checked and, if necessary, measures are initiated.

[0018] Advantages and benefits of the invention will become clearer from the following description of preferred embodiments with reference to the figures. They show:

[0019] Fig. 1: Schematic representation of a parallel kinematic movement device according to the invention

[0020] Fig. 2: Schematic representation of an adjustment unit of a parallel kinematic movement device according to the invention

[0021] Fig. 1 shows a schematic representation of a parallel kinematic movement device 1 according to the invention. This comprises a platform 2 to be moved or positioned, which is carried or supported by three leg elements 3, for example. The end of the respective leg element 3 facing the platform 2 is connected to the platform 2 via an articulated connection 4 or a first joint 40 in the form of a cardan joint. The end of the respective leg element 3 facing away from the platform 2 is also connected to an actuating element 50 of a respective adjustment unit 5, which is unique to each leg element 3, via an articulated connection 4 or a second joint 42 in the form of a cardan joint.

[0022] Each of the three adjustment units 5 has two degrees of rotational freedom and can perform rotational or tilting movements about a first rotational axis RA1 and a second rotational axis RA2 arranged perpendicularly thereto in order to adjust its position or angular position accordingly. change. Here, the two rotational degrees of freedom are driven by means of a respective associated first and second drive element 60, 62 in the form of a liner drive, wherein in Fig. 1 the first drive element 60 is arranged along the second axis of rotation RA2 and at a distance from the first axis of rotation RA1 and acts directly or immediately on the actuating element 50 of the adjusting unit 5. The second drive element 62, which in Fig. 1 is arranged along the first axis of rotation RA1 and at a distance from the second axis of rotation RA2, also acts directly, ie immediately on the actuating element 50 of the adjusting unit 5.

[0023] It is conceivable to change or manipulate the position of the actuating element 50 of an adjustment unit 5 with more than two drive elements 60, 62, preferably with three or four drive elements. In any case, the drive elements can be designed as linear drives or linear actuators, for example in the form of a voice coil actuator. It is also possible to provide drive elements that do not act on the actuating element, but directly drive the rotation axes RA1 and RA2. Furthermore, it is conceivable for the drive elements to be designed differently, whereby, for example, the first drive element 60 is designed as a voice coil actuator, while the second drive element 62 is designed as a piezo actuator that interacts with a lever transmission device.

[0024] The angular position of the actuating element 50 can be determined, for example, directly, for example via a 4-quadrant diode or an autocollimator telescope, or indirectly via a calculation from the position and orientation of the individual drives or actuators.

[0025] Since the parallel kinematic motion device shown as an example in Fig. 1 is designed for the platform to have six degrees of freedom, according to Grübler's equation, under the given boundary conditions (i.e., with two degrees of freedom with respect to the adjustment unit 5), it is necessary for each of the leg elements 3 to have four degrees of freedom of movement. These four degrees of freedom with respect to the leg elements 3 can be realized in different ways.

[0026] In the present case, each leg element 3 itself has no degree of freedom or does not comprise a joint (ie, a leg element joint) arranged between the two joint elements 40 and 42 and providing the leg element with a degree of freedom; however, the two cardan joints connected to the leg element 3 at its ends, each with two degrees of freedom of movement, provide the leg element with the total of four degrees of freedom required.

[0027] Further possibilities of combining (K) degrees and types of freedom concerning the individual joints (ie first joint 40, second joint 42 and optional leg element joint) are:

[0028] (K1): Joint 40 = three angular degrees of freedom, joint 42 = no degree of freedom, leg element joint = one shear degree of freedom (K2): Joint 40 = three angular degrees of freedom, joint 42 = one shear degree of freedom, leg element joint = no degree of freedom (K3): Joint 40 = two angular degrees of freedom, joint 42 = one shear degree of freedom, leg element joint = one angular degree of freedom (K4): Joint 40 = two angular degrees of freedom, joint 42 = one angular degree of freedom, leg element joint = one shear degree of freedom

[0029] It should be emphasized that the four different combinations (K1) to (K4) listed above were selected only as examples from a multitude of other possible combinations.

[0030] Fig. 2 schematically illustrates an adjustment unit 5 of a parallel kinematic motion device according to the invention. The adjusting element 50 is designed in the form of a rectangular plate or platform and is connected to a support element 54 surrounding or encompassing the adjusting element 50 via two articulated connections 7 in the form of a cross-spring pivot joint, which are spaced apart along the rotation axis RA2 and with respect to the rotation axis RA1 and arranged symmetrically to one another, so that the adjusting element 50 has a rotational degree of freedom with respect to the rotation axis RA2 and can perform corresponding tilting movements relative to the support element. The support element 54 is frame-shaped.

[0031] The base element 52, which completely surrounds the support element 54 and is mounted in a rotationally fixed manner, is also frame-shaped. The base element 52 and the support element 54 are connected to one another via two joint connections 7 in the form of a cross-spring pivot joint, spaced apart along the rotation axis RA1 and with respect to the rotation axis RA2 and arranged symmetrically to one another, so that the support element 54 has a rotational degree of freedom with respect to the rotation axis RA1 and can perform corresponding tilting movements relative to the rotationally fixed base element 52.

[0032] Overall, this results in the actuating element 50 being able to move or tilt relative to the base element 52 about the two rotation axes RA1 and RA2 arranged perpendicular to one another.

[0033] In addition to the adjustment unit 5 shown in Fig. 2, in which the adjusting element 50, the support element 54, and the base element 52 are nested, it is conceivable to select other embodiments for the adjustment unit 5 that allow the adjusting element 50 to be tilted about two different axes of rotation. Furthermore, it is conceivable to design the individual elements of the adjustment unit 5 shown in Fig. 2 differently in order to be better suited or adapted to the specific application. For example, it is conceivable to also design the adjusting element 50 in the shape of a frame. Furthermore, it is conceivable to replace one or more or all of the articulated connections 7 with a respective rotation bearing.

[0034] List of reference symbols 1 Parallel kinematic movement device 2 Platform 3 leg element 4 Articulated connection 5 Adjustment unit 32, 34 end sections (of the respective leg element 3) 40 first joint 42 second joint 50 Adjusting element (of the adjustment unit 5) 52 Base element (of the adjustment unit 5) 54 Support element (of the adjustment unit 5) 60 first drive element 62 second drive element 7 Articulated connection RA1 first rotation axis (of adjustment unit 5) RA2 second rotation axis (of adjustment unit 5)

Claims

Claims 1. A parallel kinematic movement device (1) with a platform (2) movable in at least six degrees of freedom, wherein the platform is supported by at least three leg elements (3), and an end section (32) of each of the leg elements (3) facing the platform (2) is coupled to the platform (2) via a first joint (40), and an end section (34) of each of the leg elements (3) facing away from the platform (2) is coupled via a second joint (42) to an actuating element (50) specific to the respective leg element (3) and movable about a first axis of rotation (RA1) and about a second axis of rotation (RA2) different from the first axis of rotation (RA1),wherein a first drive element (60) and a second drive element (62) are arranged on at least one of the actuating elements (50) in such a way that they engage directly thereon for realizing independent rotational or tilting movements of the actuating element (50) about the first axis of rotation (RA1) and about the second axis of rotation (RA2), so that the drive movements of the first drive element (60) and the second drive element (62) can be transmitted directly and independently of one another to the at least one actuating element (50), and an actuating movement of the leg element (3) associated therewith can be brought about by corresponding rotational or tilting movements of the at least one actuating element (50).

2. Parallel kinematic movement device (1) according to claim 1, characterized in that at least one of the adjusting elements (50) is cardanically mounted.

3. Parallel kinematic movement device (1) according to claim 1 or 2, characterized in that each of the adjusting elements (50) is part of a respective adjustment unit (5) which, in addition to the adjusting element (50), comprises a base element (52) and a support element (54), wherein the base element (52) is mounted in a rotationally fixed manner, and the support element (54) is mounted on the base element (52) in such a way that it can perform a rotational or tilting movement about the first axis of rotation (RA1), and the adjusting element (50) is mounted on the support element (54) in such a way that it can perform a rotational or tilting movement about the second axis of rotation (RA2).

4. Parallel kinematic movement device (1) according to claim 3, characterized in that the mounting of the carrier element (54) on the base element (52) or the mounting of the actuating element (50) on the carrier element (54) is realized by an articulated connection (7).

5. Parallel kinematic movement device according to claim 4, characterized in that that the articulated connection (7) is realized by a solid-body joint, preferably by a cross-spring pivot joint.

6. Parallel kinematic movement device according to one of claims 3 to 5, characterized in that the base element (52) and the support element (54) and optionally the actuating element (50) have a frame-shaped geometry.

7. Parallel kinematic movement device according to claim 6, characterized in that the base element (52) and the support element (54) and the actuating element (50) are arranged nested one inside the other.

8. Parallel kinematic movement device according to one of the preceding claims, characterized in that at least one of the drive elements (60, 62) is designed as a linear drive or as a rotary drive.

9. Parallel kinematic movement device according to claim 8, characterized in that the at least one drive element (60, 62) is designed as a direct drive.

10. Parallel kinematic movement device according to one of the preceding claims, characterized in that at least one of the leg elements (3) is designed or mounted in such a way that it has four degrees of freedom, one of which is a thrust degree of freedom and the remaining degrees of freedom are angular degrees of freedom.

11. Parallel kinematic movement device according to claim 10, characterized in that the degree of freedom of thrust of the at least one leg element (3) is realized by a third joint arranged between its two opposite end sections (32, 34).

12. Parallel kinematic movement device according to one of claims 3 to 11, characterized in that each of the leg elements (3) is assigned its own and separate adjustment unit (5).

13. Parallel kinematic movement device according to one of the preceding claims, characterized in that it has a device for recording and processing measurement or operating data relevant to the state of the parallel kinematic movement device, which device is designed to record and process the measurement or operating data during the running time of the parallel kinematic movement device and optionally to link them together, so that an image of the state of the parallel kinematic movement device can be derived therefrom.

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