POSITIONING DEVICE AND HAPTIC INPUT DEVICE

Abstract

The invention relates to a positioning device (1) comprising a base plate (2), an end effector (3), and a kinematic chain structure connecting the base plate (2) and the end effector (3) and providing three translational degrees of freedom with respect to the end effector (3). The kinematic chain structure comprises a main arm (5, 6) and two control arms (7, 8). The main arm (5, 6) comprises a first main arm segment (5) pivotally coupled to the base plate (2), and a second main arm segment (6) pivotally connected to the first main arm segment (5) and pivotally connected to the end effector (3). Each control arm (7, 8) comprises a first control arm segment (7) pivotally coupled to the base plate (2), and a second control arm segment (8) pivotally connected to the first control arm segment (7). and is articulated to the second main arm segment (6),wherein the first main arm segment (5) and the first control arm segments (7) are pivotable independently of one another, wherein the first main arm segment (5) has a pivot bearing (11) at a base end section (5.1) about a pivot axis (A) parallel to the base plate (2), and each first control arm segment (7) has a pivot bearing (14) at a base end section (7.1) about a pivot axis (A') parallel to the base plate (2), wherein the pivot axis (A') of each first control arm segment (7) runs parallel to the pivot axis (A) of the first main arm segment (5) or corresponds to the pivot axis (A).

Description

The invention relates to a positioning device and a haptic input device equipped therewith, which provides an interface between a human and a technical system.Haptic input devices with a control part, e.g. a handle, as a connection or input interface between a user and a technical system are known from the prior art, in order to input a hand movement into the system, e.g. in robot applications or teleoperations. The handle can be arranged on an end effector in a simple rotatable manner or via an orientation device which provides three rotational degrees of freedom as a gimbal mount. The end effector is part of a positioning device that includes a base plate and a kinematic chain structure that connects the end effector to the base plate and provides translational degrees of freedom with respect to the end effector.Such haptic input devices can be designed as passive systems for purely detecting the orientation, wherein the term "passive" is understood in the present case to mean that forces and / or torques with which a user moves the actuating part can cause a corresponding movement of the technical system. Alternatively, however, such haptic devices can also be designed as active systems for force feedback or force feedback, which use a force that can be traveled by the user via the actuating part as feedback. The forces and / or torques displayed to the user on the actuating part are generated by means of controlled energy supply from one or more actuators or motors.Known positioning devices are frequently robot devices with serial kinematics, in particular articulated arm robots such as multiaxial articulated arm robots, which have motors in the joints, i.e. in moving arm segments. This provides a high moving mass and thus leads to a reduction in the haptic quality.WO 2008 / 003417 A1 discloses a haptic input device which has a positioning device having a parallel kinematic structure for connecting the end effector to an annular base plate. The parallel kinematic structure comprises three kinematic chains, each kinematic chain having a first arm hingedly connected to a second arm. The first arms are distributed over the annular base plate and rotatably disposed on the base plate. The second arms are hingedly coupled to the end effector, each second arm consisting of two parallel rods hingedly connected at their ends to cross bars. One of the cross bars is rotatably supported on the end effector and the other cross bar is rotatably supported on the first arm. The cross bars of the second arm are parallel to the pivot axis of the respective first arm on the base plate, so that the end effector is always moved parallel to the base plate, wherein the pivot axes of the three first arms on the base plate define sides of a triangle. A positioning device with such a parallel kinematics is also known as a delta robot.DE 10 2013 106 004 A1 relates to a device having at least one manipulator for handling articles.DE 10 2014 206 209 A1 discloses a camera crane having a base for fastening the camera crane, a camera carrier for receiving a camera, and a crane arm connecting the base to the camera carrier.DE 10 2012 202 303 A1 discloses an adjustable stand for easy handling of heavy medical observation devices.DE 698 33 850 T2 relates to a device for the relative movement of two elements. In particular, the device according to the invention is intended to form a manipulator or robot.U.S. Pat. No. 3,255,893 A discloses a jib system for supporting and positioning a material handling unit.An advantage of such a parallel kinematic structure compared to articulated arm robots as a positioning device of a haptic input device is the low inherent mass, since the motors for driving the first arms are located on the base plate. A disadvantage, however, is the limited working range or a very poor ratio of the inherent variable to the movement space produced.Proceeding from this prior art, it is an object of the present invention to provide an improved positioning device which can be supplemented with a control part to form a haptic input device which is suitable for robot applications in the surgical field as a connection or input interface.This object is achieved by a positioning device having the features of claim 1.The further object of providing a correspondingly improved haptic input device is achieved by the haptic input device having the features of independent claim 12.Further developments of the devices are set out in the respective dependent claims.According to a first embodiment, a positioning device according to the invention has a base plate, an end effector and a kinematic chain structure which connects the base plate and the end effector and provides three translatory degrees of freedom with respect to the end effector. According to the invention, the kinematic chain structure has a main arm and two control arms, wherein the main arm has a first main arm segment pivotably coupled to the base plate and a second main arm segment hingedly connected to the first main arm segment and hingedly connected to the end effector. And each control arm includes a first control arm segment pivotally coupled to the base plate and a second control arm segment hingedly connected to the first control arm segment and hingedly connected to the second main arm segment. In this case, the first main arm segment and the first control arm segments can be pivoted independently of one another.Advantageously, the kinematic chain structure of the positioning device according to the invention has a small moving mass, since a static arrangement of motors with respect to the base plate is possible. By comparatively few force transmission elements with few articulation points, a favorable production of the positioning device according to the invention is advantageously made possible. In addition, the working space of the end effector is advantageously large in relation to the inherent size of the positioning device, so that the positioning device according to the invention provides excellent haptic feedback, which is advantageous in particular for use with an adjusting part, e.g. a handle, as a haptic input device for robot applications in the surgical field.According to the invention, the positioning device provides that the first main arm segment has a pivot bearing or a pivot bearing on a base end section about a pivot axis parallel to the base plate. Each first control arm segment also has a pivot bearing on a base end section about a pivot axis parallel to the base plate, wherein the pivot axis of each first control arm segment runs parallel to the pivot axis of the first main arm segment or corresponds to the pivot axis. That is, the first main arm segment and each first control arm segment may be supported on a separate axle member, which may be arranged parallel to or aligned with each other, or the first main arm segment and the two first control arm segments may be supported on a common axle member. The kinematic chain thus permits an effective arrangement with respect to the required installation space, which arrangement can be varied depending on the length of the arm segments and the achievable working space of the end effector.According to a further embodiment of the positioning device according to the invention, the articulated connection of the second control arm segment to the first control arm segment can have a first ball joint and the articulated connection of the second control arm segment to the second main arm segment can have a second ball joint. The ball joints allow the transmission of movement between the independently controllable control arms and the second main arm segment.According to a further embodiment, in the positioning device according to the invention, the first main arm segment is arranged between the two first control arm segments. The second main arm segment has, at an end facing away from the end effector, a two-leg end section with two leg ends which extend away on both sides from a longitudinal axis of the second main arm segment. At each leg end there is one of the articulated connections of the second main arm segment to the second control arm segments.The two leg ends can advantageously extend symmetrically on both sides away from the longitudinal axis of the second main arm segment, in particular orthogonally thereto, and lie in a plane with the second main arm segment.According to a further development of this embodiment of the positioning device according to the invention, the second main arm segment can have a coupling region for articulated connection to the first main arm segment, wherein the coupling region lies between the two-armed end section and an end section at which the end effector is articulated. In this case, a distance of the coupling region from the two-armed end section is smaller than a distance of the coupling region from the end section, so that the pivot radius of the end effector about the joint axis of the articulated connection to the first main arm segment is larger than a pivot radius of the two-armed end section.According to yet another embodiment of the positioning device according to the invention, the articulated connection of the second main arm segment to the first main arm segment is provided by a bridge piece having two pivot joints, the pivot axes of which are orthogonal to one another: a first pivot joint, which connects the bridge piece to the first main arm segment, has a first joint axis parallel to the pivot axis of the first main arm segment, and a second pivot joint, which connects the bridge piece to the second main arm segment, has a second joint axis, which runs orthogonally to the first joint axis. The second joint axis furthermore extends parallel to a third joint axis of a third swivel joint which provides the articulated connection of the second main arm segment to the end effector.As a pivot joint, a rotatable joint having a degree of freedom is referred to herein, wherein the articulated elements can rotate about the joint axis. By means of the bridge piece with the two coupled pivot joints and the coupling with the control arms, almost any desired trajectories of the second main arm segment can be realized with the end effector.According to yet another development of the positioning device according to the invention, the bridge piece has a cross strut section adjacent to the two pivot joints. In addition, the positioning device has a compensating arm which is connected on the one hand in an articulated manner to the cross strut section and on the other hand in an articulated manner to the end effector. This prevents a change in position of the kinematic chain structure from leading to a change in orientation at the end effector.Furthermore, according to a further embodiment of the positioning device according to the invention, the bridge piece can have a bearing block section with at least one bearing eye which defines the first joint axis, and an axis section which defines the second joint axis. The first pivot joint with the first main arm segment is formed by the bearing block section and the second pivot joint with the second main arm segment is formed by the axle section. For this purpose, the first main arm segment can have or be connected to an axle pin which is mounted in the at least one bearing eye of the bearing block section, and the second main arm segment can have a bearing opening for rotatably mounting the axle section.In this case, according to yet another embodiment of the positioning device according to the invention, it can be provided that the cross strut section extends from the bearing block section parallel to the first joint axis. The articulated connection of the compensating arm to the cross strut section is provided by a fourth pivot joint with an articulation axis parallel to the second articulation axis of the bridge piece. The articulated connection of the compensating arm to the end effector is provided by a fifth pivot joint having an articulation axis parallel to the third articulation axis, wherein a length of the compensating arm is adapted to the distance of the coupling region from the end section and a length of the cross strut section is adapted to a distance of the third pivot joint on the end effector from the fifth pivot joint in each case such that the compensating arm is always arranged parallel to the second main arm segment and the bridge piece is always arranged parallel to the end effector.According to yet another embodiment of the positioning device according to the invention, the first main arm segment and each first control arm segment can be driven independently of one another by a motor, which is arranged in the region of the base plate or on the base plate. In this case, the base section of the first main arm segment and the base section of each first control arm segment are correspondingly configured for engagement with a drive element of the respective motor.For example, according to a further development of the positioning device according to the invention, the first main arm segment can have an output wheel element, the pivot axis of which corresponds to the pivot axis of the base section of the first main arm segment. That is to say that the base section either provides the output gear element itself with a correspondingly formed circumferential profile or is connected coaxially to an output gear. In an analogous manner, each first control arm segment has an output wheel element, the pivot axis of which corresponds to the pivot axis of the base section of the respective first control arm segment, wherein here too the output wheel element is provided by the base section itself with a correspondingly formed circumferential profile or by an output wheel connected coaxially to the base section. For engagement with the output gear elements of the main arm segment and the control arm segments, each motor is connected to a drive gear as a drive element. Thus, each drive wheel and the output wheel element respectively engaged therewith form a transmission which is selected from a group comprising at least one toothed transmission, a friction wheel transmission and a belt or chain transmission.Gear drives are understood to mean positive-locking gears which have at least two toothed machine elements selected from a group comprising spur gears, bevel gears, gear racks, crown gears, worm gears and worm gears. A friction wheel transmission means a force-locking transmission in which rotationally symmetrical rolling bodies roll with respect to one another as drive and output elements having the same or different diameters. Belt and chain transmissions are traction drive transmissions with a belt or a chain as a means for moving or transmitting force between pulleys or sprockets as input and output elements.According to a first embodiment, a haptic input device according to the invention has a handle and a positioning device according to the invention having a base plate, an end effector and a kinematic chain structure. The kinematic chain structure connects the base plate and the end effector and provides three degrees of translational freedom with respect to the end effector connected to the handle.According to a further embodiment of the haptic input device according to the invention, the handle can be connected to the end effector via an orientation device which provides at least one rotational degree of freedom with respect to the handle.According to yet another embodiment, the orientation device provides three rotational degrees of freedom with respect to the handle.Other embodiments of the devices, as well as some of the advantages associated with these and other embodiments, will be apparent and better understood from the following detailed description with reference to the accompanying figures. Items or parts thereof that are substantially the same or similar may be provided with the same reference numerals. The figures are merely schematic representations of embodiments of the invention.The following are shown: FIG. 1 shows a perspective view of a positioning device according to the invention with the end effector in a middle position, FIG. 2 shows an enlarged view of a detail of the positioning device according to the invention from FIG. 1, FIG. 3 shows a perspective view of the positioning device according to the invention from FIG. 1 with the end effector moved to the bottom and back to the right, FIG. 4 shows a perspective view of the positioning device according to the invention from FIG. 1 with the end effector moved downward and forwards, FIG. 5 shows a perspective view of the positioning device according to the invention from FIG. 1 with the end effector moved to the bottom and forward left, FIG. 6 shows a perspective view of the positioning device according to the invention from FIG. 1 with the end effector moved downward, FIG. 7 shows a perspective view of the positioning device according to the invention from FIG. 1 with the end effector in the middle position from below, FIG. 8 shows a perspective view of the positioning device according to the invention from FIG. 7 with the end effector moved to the left and forward, from below, FIG. 9 shows a perspective view of the positioning device according to the invention from FIG. 7 with the end effector moved to the right and forward, from below, FIG. 10 shows a perspective view of a haptic input device according to the invention with the positioning device with the end effector in the middle position from FIG. 1.The invention relates to a positioning device and a haptic input device with such a positioning device, which has kinematics that allow a static arrangement of actuators or motors and thus ensures low moving masses, and at the same time provides a large working space for the end effector in relation to the inherent size of the positioning device.FIGS. 1 and 3 to 9 show an embodiment of a positioning device 1 according to the invention in different positions; a corresponding haptic input device 20 is illustrated in FIG. 10.The positioning device 1 consists of a base plate 2, an end effector 3 and a kinematic chain structure which connects the base plate 2 and the end effector 3 and provides three translatory degrees of freedom with respect to the end effector 3. FIGS. 1, 3 and 5 show a corresponding coordinate system illustrating the orientation of the three translational degrees of freedom forward / backward, upward / downward and right / left, which are used to describe movements of the end effector 3 with respect to the base plate 2. The movement directions are selected with respect to a user who grasps a handle 24 arranged on the end effector 3 (cf. haptic input device 20 in FIG. 10 ) with one hand.The kinematic chain structure comprises a main arm 5, 6 with a first main arm segment 5 and a second main arm segment 6, which are hingedly connected to each other. In addition, the first main arm segment 5 is rotatably coupled to the base plate 2, and the second main arm segment 6 is hingedly connected to the end effector 3. Furthermore, the kinematic chain structure comprises two control arms 7, 8 each with a first control arm segment 7 and a second control arm segment 8, which are connected to one another in an articulated manner. Each first control arm segment 7 is rotatably coupled to the base plate 2, while both second control arm segments 8 are pivotally connected to the second main arm segment 6. The articulated connection between the first main arm segment 5 and the second main arm segment 6 is located between the articulated connection of the second main arm segment 6 to the end effector 3 and the articulated connections of the second main arm segment 6 to the second control arm segments 8.The first main arm segment 5 has a pivot bearing 11 at a base end section 5.1 about a pivot axis A which is parallel to the base plate 2. The base end portion 5.1 denotes the base plate near end of the first main arm segment 5, the other end of which provides the coupling portion 5.2 for the articulated connection to the second main arm segment 6. Each first control arm segment 7 also has a pivot bearing 14 on a base end section 7.1 about a pivot axis A' which is parallel to the base plate 2. Here too, the base end section 7.1 is present at the end of the first control arm segments 7 close to the base plate, which have a coupling section 7.2 at the other end for the articulated connection to the respective second control arm segment 8.In the embodiment shown, the pivot axis A' of the first control arm segment 7 corresponds to the pivot axis A of the first main arm segment 5, so that the two first control arm segments 7 and the first main arm segment 5 arranged therebetween are mounted on a common axle element 4. The bearing sections 21 for the axle element 4 which are illustrated in the figures and are connected to the base plate 2 are to be understood as being only exemplary. It is of course possible for the mounting sections and base plate to be designed differently. Furthermore, it is not necessary for the first control arm segments and the first main arm segment to be arranged on a common axle element: it is also possible for each first control arm segment and the first main arm segment to be arranged on a separate axle element, wherein the pivot axes A' of the first control arm segments also do not necessarily have to correspond to the pivot axis A of the first main arm segment, but can also run parallel thereto. However, the common arrangement represents an advantageously space-saving and simple variant.In the arrangement shown of the first main arm segment 5 between the two first control arm segments 7, the second main arm segment 6 is T-shaped and has a two-armed end section 6.1 at the end facing away from the end effector 3. This comprises two leg ends 6.1a, 6.1b which extend symmetrically on both sides orthogonally away from the longitudinal axis of the second main arm segment 6. At each leg end 6.1a, 6.1b, one of the articulated connections of the second main arm segment 6 to the second control arm segments 8 is formed. In the present case, the articulated connections of the second control arm segment 8 to the first control arm segment 7 are provided by a first ball joint 15 and to the second main arm segment 6 by a second ball joint 16.The coupling region 6.2 of the second main arm segment 6 for articulated connection to the first main arm segment 5 lies between the two-sided end section 6.1 and the end section 6.3 with the end effector 3. The ratio between the distances of the coupling region 6.2 to the two-armed end section 6.1 and to the end section 6.3 is approximately 1:3 in the example shown, but can deviate entirely therefrom, depending on the desired range of movement or lever ratio.In order that the second main arm segment 6 can be pivoted about two orthogonal axes with respect to the first main arm segment 5, the articulated connection of the second main arm segment 6 to the first main arm segment 5 is provided by a bridge piece 9 having two pivot joints 12, 13, as can be seen in the enlarged detailed illustration in FIG. 2. The first pivot joint 12 connects the bridge piece 9 to the first main arm segment 5 and defines a first joint axis B which runs parallel to the pivot axis A of the first main arm segment 5. The second pivot joint 13 connects the bridge piece 9 to the second main arm segment 6 and defines a second joint axis C that is orthogonal to the first joint axis B. As can be seen in FIG. 1, the second joint axis C extends parallel to a third joint axis D of a third pivot joint 17 which provides the articulated connection of the second main arm segment 6 to the end effector 3.In order to form the first pivot joint 12, the bridge piece 9 in the exemplary embodiment shown has a bearing block section 9.1 with two bearing eyes 9.2, which define the first joint axis B, in order to rotatably support the coupling section 5.2 of the first main arm segment 5, for example by means of an axle element (not shown in the figure) which extends through the two bearing eyes 9.2 and a corresponding bearing eye in the coupling section 5.2. For the second pivot joint 13, the bridge piece 9 has an axle section 9.3 in the opposite direction to the bearing block section 9.1, which is rotatably mounted in a bearing opening (not shown) in the coupling region 6.2 of the second main arm segment 6 and defines the second joint axis C.Since the first main arm segment 5 and the two first control arm segments 7 are rotatable independently of one another with respect to the base plate 2, the second main arm segment 6 can be pivoted not only with rotation of the first main arm segment 5 in a first plane on a circular path about the pivot axis A, but can be bent or angled both with respect to the first main arm segment 5 on a circular path about the first joint axis B and can also be pivoted in a second plane orthogonal to the first plane on a circular path about the second joint axis C. Angle angle is understood here to mean that the angle between the second main arm segment 6 and the first main arm segment 5 is reduced, while angle angle refers here to the increase of the angle between the second main arm segment 6 and the first main arm segment 5. Any movement is possible individually as well as any combination of these movements. The respective movements of the second main arm segment 6 or of the end effector 3 arranged thereon describe individually a circular path, but can overlap and result in combination in translatory movements of the end effector 3.FIGS. 3 to 9 show examples of different positions of the positioning device 1, which illustrate the working space of the end effector 3, starting from a middle position of the positioning device 1 which is illustrated in FIGS. 1 and 7. In the middle position, the second main arm segment 6 with the end effector 3 is approximately orthogonal to the first main arm segment 5, wherein both first control arm segments 7 are approximately orthogonal to the first main arm segment 5 and point away from the end effector 3. The T-shaped two-armed end section 6.1, at the ends 6.1a, 6.1b of which the second control arm segments 8 are articulated, is parallel to the pivot axis A.To transfer the positioning device 1 from FIG. 1 into the position shown in FIG. 3, the end effector 3 is moved downwards and back to the right, wherein the first main arm segment 5 and the two first control arm segments 7-viewed from the left-are rotated clockwise. The first control arm segments 7 are rotated further than the first main arm segment 5, so that a rotational movement of the second main arm segment 6 about the first joint axis B is superimposed with the rotational movement of the first main arm segment 5 about the pivot axis A. The superimposed rotational movements lead to an angle of the second main arm segment 6 from the first main arm segment 5 and result in the movement of the end effector 3 downward and back. For the movement of the end effector 3 to the right, the left first control arm segment 7 is rotated further than the right first control arm segment 7, so that the left end 6.1 aof the two-armed end section 6.1 is moved further back than the right end 6.1 b, whereby the second main arm segment 6 is pivoted counterclockwise about the second joint axis C-viewed from above.In FIG. 4, the end effector 3 is moved downward and forward starting from the position of the positioning device 1 in FIG. 1, wherein the first main arm segment 5 and the two first control arm segments 7 are rotated counterclockwise-viewed from the left-wherein the first main arm segment 5 is rotated further than the two first control arm segments 7, so that the superimposed rotational movements about the pivot axis A and the first joint axis B lead to an angle of the second main arm segment 6 to the first main arm segment 5 and result in the movement of the end effector 3 downward and forward.For the movement of the end effector 3 from FIG. 1 to the bottom left and in front into the position of the positioning device 1 in FIG. 5, a rotational movement of the second main arm segment 6 about the second joint axis C-viewed from above-in the clockwise direction and an angle of the second main arm segment 6 with respect to the first main arm segment 5, i.e. rotation of the second main arm segment 6 about the first joint axis B are superimposed for the angle, the two first control arm segments 7-viewed from the left-in the clockwise direction are thereby rotated without the first main arm segment 5 being moved. For the movement of the end effector 3 to the left, the right first control arm segment 7 is rotated further than the left first control arm segment 7, so that the left end 6.1 aof the two-armed end section 6.1 is moved forward, whereby the second main arm segment 6 is pivoted clockwise about the second joint axis C-viewed from above.In order to transfer the positioning device 1 from the middle position shown in FIG. 1 into the position shown in FIG. 6, the end effector 3 is moved downward, wherein the two first control arm segments 7-viewed from the left-are rotated clockwise in order to angle the second main arm segment 6 to the first main arm segment 5. The first main arm segment 5 is rotated clockwise only slightly, as viewed from the left, in order to compensate for the forward movement portion of the rotational movement of the second main arm segment 6 about the first joint axis B by the rearward movement portion of the rotational movement about the pivot axis A.FIGS. 7, 8 and 9 show the positioning device 1 with the end effector 3 in the middle position and in the position moved forward to the left and forward to the right. The third degree of freedom up / down is not specified in the associated coordinate system in FIG. 9, since the direction "down" goes out of the sheet plane and the direction "up" goes into the sheet plane. In order to move the end effector 3 from the middle position in FIG. 7 to the left and somewhat in front (FIG. 8 ) or to the right and further in front (FIG. 9 ), the first control arm segments 7 are correspondingly rotated with respect to the first main arm segment 5 in order to deflect the two-armed end section 6.1 out of the position parallel to the pivot axis A in the middle position and to correspondingly rotate the second main arm segment 6 about the second joint axis C (indicated in FIG. 7 by cross wheels).The views from below in FIGS. 7 to 9 show above all the mode of operation of the passive parallel kinematics formed by the compensating arm 10, by means of which the orientation of the end effector 3 over the movement space of the positioning device 1 remains unchanged when the second main arm segment 6 is rotated. This can be seen from the constantly parallel orientation of the end effector 3, which is here exemplarily cuboidal, with respect to the pivot axis A.The compensating arm 10 is connected in a hinged manner parallel to the second main arm segment 6 to the end effector 3 and to the bridge piece 9, which has a cross strut section 9.4 adjacent to the two pivot joints 12, 13 (cf. FIG. 2 ). The cross strut section 9.4 extends from the bearing block section 9.1 parallel to the first joint axis B and is connected to the compensating arm 10 to form a fourth pivot joint 18, the joint axis C' of which is parallel to the second joint axis C. At the other end of the compensation arm 10, the articulated connection to the end effector 3 is provided by a fifth pivot joint 19, the joint axis D' of which is parallel to the third joint axis D of the third pivot joint 17 between the second main arm segment 6 and the end effector 3.In order to form the passive parallel kinematics, the length of the compensation arm 10 is adapted to the distance of the coupling region 6.2 from the end section 6.3 such that the distance between the joint axes C' and D' corresponds to the distance between the second joint axis C and the third joint axis D. Analogously, the length of the cross strut section 9.4 is adapted such that the distance of the joint axis C' to the second joint axis C corresponds to the distance of the joint axis D' of the fifth pivot joint 19 to the third joint axis D of the third pivot joint 17 on the end effector 3, so that not only the compensating arm 10 is always parallel to the second main arm segment 6, but also the end effector 3 is always parallel to the bridge piece 9 or the first joint axis B, and thus parallel to the pivot axis A.FIG. 10 shows a haptic input device 20 which has the prescribed positioning device 1 and a handle 24 which is connected to the end effector 3 via an orientation device 23 which, in the example shown, provides a rotational degree of freedom, namely the rotation of the handle 24 about the longitudinal axis of the orientation device 23 indicated by the double arrow. Alternatively, more complex wrist structures can of course also be used as the orientation device 23 for connecting the handle 24 to the end effector 3, which can then provide three rotational degrees of freedom.The haptic input device 20 depicted in FIG. 10 is designed as an active system which uses a force that can be traveled by the user via the handle 24 as feedback, which is generated by means of controlled energy supply of motors. Therefore, the positioning device 1 comprises motors 22, and the orientation device 23 also comprises a motor 22' for generating feedback.In the positioning device 1, the first main arm segment 5 and each first control arm segment 7 are driven independently of one another by a motor 22, which is arranged by means of corresponding holders (not shown in FIG. 10 ) in a fixed position with respect to the base plate 2, i.e. on or in the vicinity of the base plate 2. Holders or housing elements for the stationary arrangement of motors are known, for which reason further explanations are omitted here. The motors 22 are arranged with respect to the base plate 2 such that the base section 5.1 of the first main arm segment 5 and the base section 7.1 of each first control arm segment 7 are in engagement with a drive element 22.1 of the respectively associated motor 22. In the example shown, the base section 5.1 of the first main arm segment 5 and the base sections 7.1 of the first control arm segments 7 each form a pitch circle disk as an output wheel element, which represents a first rolling element, which rolls on the drive element 22.1, which is likewise designed as a rolling element. The direction of rotation of the motor 22 can be switched, so that the first main arm segment 5 and the two first control arm segments 7 can be driven in or counter-clockwise about the axis of rotation A.Of course, alternative embodiments with other gears are conceivable to the positioning device 1 with the simple friction wheel gear shown by way of example in order to transmit the force or the torque of the motors to the first main arm segment 5 and the two first control arm segments 7. Various gears are possible here, for example gear drives with at least two meshing gear wheel elements or traction mechanism gears with at least two traction mechanism wheel elements connected via a traction mechanism such as a belt or chain, so that the output wheel elements of the first main arm segment 5 and the first control arm segments 7 and the drive elements of the associated motors 22 are correspondingly designed as tooth or traction mechanism wheel elements, or are connected thereto.As an alternative to the example depicted in FIG. 10, the haptic input device 20 can be designed with a positioning device 1 and a handle 24 as a passive system without motors for pure orientation detection, wherein the user moves the handle 24 in order to cause a corresponding movement of the technical system.

Claims

Positioning device (1) comprising a base plate (2), an end effector (3) and a kinematic chain structure connecting the base plate (2) and the end effector (3) and providing three translatory degrees of freedom with respect to the end effector (3), wherein the kinematic chain structure comprises a main arm (5, 6) and two control arms (7, 8), wherein the main arm (5, 6) comprises a first main arm segment (5) pivotably coupled to the base plate (2) and a second main arm segment (6) pivotably coupled to the first main arm segment (5) and pivotably coupled to the end effector (3), and each control arm (7, 8) comprises a first control arm segment (7) pivotably coupled to the base plate (2) and a second control arm segment (8), which is articulated to the first control arm segment (7) and articulated to the second main arm segment (6), wherein the first main arm segment (5) and the first control arm segments (7) are pivotable independently of one another, wherein the first main arm segment (5) has at a base end section (5.1) a pivot bearing (11) about a pivot axis (A) parallel to the base plate (2), and each first control arm segment (7) has at a base end section (7.1) a pivot bearing (14) about a pivot axis (A') parallel to the base plate (2), wherein the pivot axis (A') of each first control arm segment (7) runs parallel to the pivot axis (A) of the first main arm segment (5) or corresponds to the pivot axis (A).Positioning device (1) according to claim 1, characterised in that the articulated connection of the second control arm segment (8) to the first control arm segment (7) has a first ball joint (15), and the articulated connection of the second control arm segment (8) to the second main arm segment (6) has a second ball joint (16).Positioning device (1) according to at least one of claims 1 or 2, characterised in that the first main arm segment (5) is arranged between the two first control arm segments (7), and the second main arm segment (6) has, at an end facing away from the end effector (3), a two-leg end section (6.1) with two leg ends (6.1a, 6.1b) which extend away on both sides from a longitudinal axis of the second main arm segment (6), wherein at each leg end (6.1a, 6.1b) one of the articulated connections of the second main arm segment (6) to the second control arm segments (8) is present.Positioning device (1) according to claim 3, characterised in that the second main arm segment (6) has a coupling region (6.2) for articulated connection to the first main arm segment (5) and the coupling region (6.2) lies between the two-sided end section (6.1) and an end section (6.3) at which the end effector (3) is articulated, wherein a distance of the coupling region (6.2) from the two-sided end section (6.1) is smaller than a distance of the coupling region (6.2) from the end section (6.3).Positioning device (1) according to at least one of claims 1 to 4, characterised in that the articulated connection of the second main arm segment (6) to the first main arm segment (5) is provided by a bridge piece (9) having two pivot joints (12, 13), wherein a first pivot joint (12) connecting the bridge piece (9) to the first main arm segment (5) has a first joint axis (B) parallel to the pivot axis (A) of the first main arm segment (5), and a second pivot joint (13) connecting the bridge piece (9) to the second main arm segment (6) has a second joint axis (C) which runs orthogonally to the first joint axis (B), and wherein the second joint axis (C) extends parallel to a third joint axis (D) of a third swivel joint (17), which provides the articulated connection of the second main arm segment (6) to the end effector (3).Positioning device (1) according to claim 5, characterised in that the bridge piece (9) has a cross strut section (9.4) adjacent to the two pivot joints (12, 13) and the positioning device (1) has a compensating arm (10), which is connected in an articulated manner to the cross strut section (9.4) and in an articulated manner to the end effector (3).Positioning device (1) according to claim 5 or 6, characterised in that the bridge piece (9) has a bearing block section (9.1) with at least one bearing eye (9.2) and an axle section (9.3), wherein the bearing eye (9.2) defines the first joint axis (B) and the axle section (9.3) defines the second joint axis (C), and wherein the first pivot joint (12) with the first main arm segment (5) is formed by the bearing block section (9.1) and the second pivot joint (13) with the second main arm segment (6) is formed by the axle section (9.3).Positioning device (1) according to claim 7, characterised in that the cross strut section (9.4) extends from the bearing block section (9.1) parallel to the first joint axis (B), and the articulated connection of the compensating arm (10) to the cross strut section (9.4) is provided by a fourth pivot joint (18) with an articulation axis (C') parallel to the second joint axis (C), and the articulated connection of the compensating arm (10) to the end effector (3) is provided by a fifth pivot joint (19) with an articulation axis (D') parallel to the third joint axis (D), wherein a length of the compensating arm (10) is adapted to the distance of the coupling region (6.2) from the end portion (6.3) and a length of the cross strut portion (9.4) is adapted to a distance of the third pivot joint (17) on the end effector (3) from the fifth pivot joint (19) in each case such that the compensating arm (10) is always arranged parallel to the second main arm segment (6) and the bridge piece (9) is always arranged parallel to the end effector (3).Positioning device (1) according to at least one of Claims 1 to 8, characterized in that the first main arm segment (5) and each first control arm segment (7) can be driven independently of one another by a respective motor (22) which is arranged on the base plate (2), wherein the base section (5.1) of the first main arm segment (5) and the base section (7.1) of each first control arm segment (7) are designed to engage with a drive element (22.1) of the respective motor (22).Positioning device (1) according to claim 9, characterised in that the first main arm segment (5) has an output wheel element, the pivot axis of which corresponds to the pivot axis (A) of the base section (5.1) of the first main arm segment (5), and each first control arm segment (7) has an output wheel element, the pivot axis of which corresponds to the pivot axis (A') of the base section (7.1) of the respective first control arm segment (7), and the drive element (22.1) of each motor (22) is a drive wheel (22.1) which is in engagement with in each case one of the output wheel elements.Haptic input device (20) comprising a handle (24) and a positioning device (1) comprising a base plate (2), an end effector (3) and a kinematic chain structure connecting the base plate (2) and the end effector (3) and providing three degrees of translation with respect to the end effector (3) connected to the handle (24), characterized in that the positioning device (1) is a positioning device (1) according to at least one of claims 1 to 11.Haptic input device (20) according to claim 11, characterized in that the handle (24) is connected to the end effector (3) via an orientation device (23), which provides at least one rotational degree of freedom, preferably three rotational degrees of freedom with respect to the handle (24).

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