END EFFECTOR SUPPORT ELEMENT AND ROBOT SYSTEM WITH A CONFORMITY MECHANISM WITH GRAVITY-CONNECTED SELF-CENTERING

Abstract

End effector support element (20) for a system (10) comprising: a first conformity mechanism (24a) which includes: two base rails (30), wherein a first base rail (30a) of the two base rails (30) is offset to a second base rail (30b) of the two base rails (30) in a first direction of movement (42) of an end effector (12), wherein each base rail (30a, 30b) has a curved profile; two conformal rails (38), each operationally connected to a corresponding base rail (30a, 30b) of the two base rails (30), each conformal rail (38) having a complementary curved profile to each of the base rails (30a, 30b); and several rolling elements (40) arranged between each base rail (30a, 30b) and each conformal rail (38) to operationally connect the base rail (30a, 30b) to the conformal rail (38); and a position sensor arranged on the first conformance mechanism (24a) to detect a position of the conforming rails (38) relative to the corresponding base rails (30a, 30b); wherein each conformal rail (38) is configured to be symmetrically pivotable connected to the end effector (12) to allow movement of the end effector (12) in the first direction of movement (42).

Description

INTRODUCTION

[0001] The present invention relates to robot systems and in particular to support elements for arms of robot systems.

[0002] Robotic systems or other actuated handling systems use arms with end effectors that enable interaction with, for example, humans in shared applications or machines in flow production applications. Such arms often incorporate support elements with conformance mechanisms that allow physical interaction with and movement within the environment with low resistance and therefore low force, enabling multi-degree-of-freedom motion. The conformance mechanism might be a four-link linkage configuration or similar. However, such configurations have limitations, as they are often large and lack a self-centering feature, resulting in cumbersome operation of the mechanism.

[0003] For background information, reference should be made here to the publications DE 10 2022 126 199 A1, US 2020 / 0 376 682 A1 and US 5 909 941 A. SUMMARY

[0004] According to an exemplary embodiment, an end-effector support element for a system comprises a first conformance mechanism containing two base rails, wherein a first base rail of the two base rails is offset relative to a second base rail of the two base rails in a first direction of movement of an end effector. Each base rail has a curved profile. The support element comprises two conforming rails. Each conforming rail is operationally connected to a corresponding base rail of the two base rails. Each conforming rail has a complementary curved profile to each of the base rails. Several rolling elements are arranged between each base rail and each conforming rail to operationally connect the base rail to the conforming rail.The first conformance mechanism incorporates a position sensor to detect the position of the conforming rails relative to the corresponding base rails. Each conforming rail is configured to pivot symmetrically to the end effector, allowing movement of the end effector in the first direction of motion.

[0005] In addition to one or more of the features described here, the support element includes a base plate to which the two base rails are attached.

[0006] In addition to one or more of the features described here, the two base rails are configured such that the end effector returns to a neutral position relative to the first direction of movement due to gravity.

[0007] In addition to one or more of the features described here, the two conformal rails are arranged vertically below the two base rails.

[0008] In addition to one or more of the features described here, a locking mechanism optionally locks the position of the conformal rails relative to the corresponding base rails.

[0009] In addition to one or more of the features described here, the position sensor includes a rotary sensor that detects the rotation of a rotary joint connecting the end effector to the base rail, or a linear sensor that detects the relative movement of the conformal rail with respect to the base rail.

[0010] In addition to one or more of the features described herein, the bracket includes a second conformance mechanism comprising two upper rails. A first upper rail of the two upper rails is offset from a second upper rail of the two upper rails in a second direction of movement of the end effector. Each upper rail has the same curved profile. The second conformance mechanism further comprises two lower rails. Each lower rail is operatively connected to a corresponding base rail of the two upper rails. Each lower rail has a complementary curved profile to each of the upper rails. Several rolling elements are arranged between each upper rail and each lower rail to operatively connect the upper rail to the lower rail.Each lower rail is pivotally connected to a first conformance mechanism to allow movement of the end effector in the second direction of motion. A second position sensor is located on the second conformance mechanism to detect the position of the lower rails relative to the corresponding upper rails.

[0011] In addition to one or more of the features described here, the second conformance mechanism is arranged vertically above the first conformance mechanism.

[0012] In addition to one or more of the features described here, the second direction of movement is perpendicular to the first direction of movement.

[0013] In addition to one or more of the features described here, the two upper rails are configured such that the end effector returns to a neutral position relative to the second direction of movement due to gravity.

[0014] According to another exemplary embodiment, a robot system comprises a robot, an end effector operationally connected to the robot, and an end effector support element that operationally connects the end effector to the robot. The end effector support element includes a first conformance mechanism comprising two base rails. One of the two base rails is offset relative to the other in a first direction of movement of the end effector. Each base rail has the same curved profile. The support element further comprises two conformal rails. Each conformal rail is operationally connected to a corresponding base rail. Each conformal rail has a complementary curved profile to each of the base rails.Between each base rail and each conformal rail, several rolling elements are arranged to operationally connect the base rail to the conformal rail. A position sensor is located on the first conformal rail mechanism to detect the position of the conformal rails relative to the corresponding base rails. Each conformal rail is configured to pivotally connect to the end effector to allow movement of the end effector in the first direction of motion. In response to a detected position of the conformal rails, the robot's position relative to the corresponding base rails is changed.

[0015] In addition to one or more of the features described here, the two base rails are configured such that the end effector returns to a neutral position relative to the first direction of movement due to gravity.

[0016] In addition to one or more of the features described here, the two conformal rails are arranged vertically below the two base rails.

[0017] In addition to one or more of the features described here, a locking mechanism optionally locks the position of the conformal rails relative to the corresponding base rails.

[0018] In addition to one or more of the features described here, the position sensor includes a rotary sensor that detects the rotation of a rotary joint connecting the end effector to the base rail, or a linear sensor that detects the relative movement of the conformal rail with respect to the base rail.

[0019] In addition to one or more of the features described herein, a second conformance mechanism includes two upper rails. A first upper rail of the two upper rails is offset from a second upper rail of the two upper rails in a second direction of motion of the end effector. Each upper rail has the same curved profile. The support element further includes two lower rails. Each lower rail is operationally connected to a corresponding base rail of the two upper rails. Each lower rail has a complementary curved profile to each of the upper rails. Several rolling elements are arranged between each upper rail and each lower rail to operationally connect the upper rail to the lower rail.The second conformance mechanism incorporates a second position sensor to detect the position of the lower rails relative to the corresponding upper rails. Each lower rail is pivotally connected to a first conformance mechanism to allow movement of the end effector in the second direction of motion.

[0020] In addition to one or more of the features described here, the second conformance mechanism is arranged vertically above the first conformance mechanism.

[0021] In addition to one or more of the features described here, the second direction of movement is perpendicular to the first direction of movement.

[0022] In addition to one or more of the features described here, the two upper rails are configured such that the end effector returns to a neutral position relative to the second direction of movement due to gravity.

[0023] In addition to one or more of the features described here, the end effector is a pointer or sensor probe or gripping tool or welding tool.

[0024] The features and advantages described above, and further features and advantages of the invention, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features, advantages and details appear only as examples in the following detailed description, which refers to the drawings; they show: Fig. 1. A perspective view of an embodiment of a robot system; Fig. 2 a schematic representation of an embodiment of a first conformity mechanism; and Fig. 3 a schematic representation of an embodiment of a second conformity mechanism. DETAILED DESCRIPTION

[0026] The following description is merely exemplary. It should be noted that throughout the drawings, corresponding reference symbols denote similar or corresponding sections and features.

[0027] In Fig. Figure 1 shows an embodiment of a robot system 10 according to an exemplary embodiment. The robot system 10 includes an end effector 12, which is connected to and carries an engagement element 14. According to some embodiments, the engagement element 14 is a pointer, a sensor probe, a gripper, a welding tool, or the like. It should be noted that these are merely examples of engagement elements 14, and those skilled in the art will readily understand that the engagement element 14 can take other forms. The robot system 10 may further include a user interface 16, which is connected to the engagement element 14 via the end effector 12 to control the movement or operation of the engagement element 14. According to some embodiments, the user interface 16 includes one or more handles 18, triggers, or other controls.

[0028] The end effector 12 is connected to a relatively fixed support element 20 and, according to some embodiments, via the support element 20 to a robot 80 or another mechanism to drive the movement of the end effector 12. This connection is made via a conformal arrangement 22. According to the embodiment of the Fig. 1 the conforming arrangement 22 includes two conforming mechanisms 24 arranged along a stacking axis 26, wherein a first conforming mechanism 24a is rotatably offset relative to a second conforming mechanism 24b relative to the stacking axis 26.

[0029] As in Fig. 2 and with continued reference to Fig. As shown in Figure 1, an embodiment of a conformance mechanism 24 will now be described in more detail. The first conformance mechanism 24a comprises a base plate 28, which has two base rails 30a and 30b (also referred to as 30) connected to it and, in some embodiments, extending vertically beneath the base plate 28. Each of the base rails 30 is curved and connected to the base plate 28 at its end sections 32. According to some embodiments, the base rails 30 each have a constant radius 36 and are arranged such that the end sections 32 are positioned vertically above a central section 34 of the base rails 30. According to one embodiment, the radii of each of the base rails 30 are equal. A first base rail 30a is offset relative to a second base rail 30b along a first direction of movement 42 of the end effector 12.

[0030] Each of the base rails 30 is connected to a conforming rail 38, with several rolling elements 40 arranged between each conforming rail 38 and the corresponding base rail 30 to assist the movement of the conforming rails 38 relative to the corresponding base rails 30. The conforming rails 38 are curved, radially offset from the base rails 30 to accommodate the multiple rolling elements 40, and share a common center of curvature. In the arrangement of the first conforming mechanism 24a, each of the conforming rails 38 is connected to the end effector 12 at a pivot point 44 via a pivot arm 46. The connection is such that the pivot arm 46 rotates about the pivot point 44 relative to the end effector 12, enabling movement of the end effector 12 in the first direction of motion 42.The position and configuration of the base rails 30 and the conforming rails 38, due to the arrangement of the central section 34 vertically below the end sections 32, cause the end effector 12 to return to a first neutral position 48 relative to the first direction of movement 42 due to gravity in the absence of any further applied force. According to some embodiments, the first conforming mechanism 24a may include a locking device 90, which is arranged, for example, at the pivot point 44, to selectively lock the position of the first conforming mechanism 24a. The locking device may also be, for example, a braking or clamping device that locks the conforming rail 38 to the base rail 30.

[0031] As in Fig. As shown in Figure 1, the conforming arrangement 22, according to some embodiments, includes a second conforming mechanism 24b, which is stacked on top of the first conforming mechanism 24a along the stacking axis 26. The second conforming mechanism 24b enables and controls the movement of the end effector 12 in a second direction of movement 50, which, according to some embodiments, is perpendicular to the first direction of movement 42.

[0032] With reference to Fig. Section 3 describes in more detail an embodiment of the second conformance mechanism 24b. The second conformance mechanism 24b comprises an upper plate 52, which has two upper rails 54 connected to it and, according to some embodiments, extending vertically below the upper plate 52. Each of the upper rails 54 is curved and connected to the upper plate 52 at the end sections 56 of the upper rails 54. According to some embodiments, each of the upper rails 54 has a constant radius 58 and is arranged such that the end sections 56 are positioned vertically above a central section 60 of the upper rails 54. According to one embodiment, the radii of each of the upper rails 54 are equal. A first upper rail 54 is offset relative to a second upper rail 54 along the second direction of movement 50 of the end effector 12.

[0033] Each of the upper rails 54 is connected to a lower rail 62, with several rolling elements 64 arranged between each lower rail 62 and the corresponding upper rail 54 to facilitate the movement of the lower rails 62 relative to the corresponding upper rails 54. The lower rails 62 are curved, radially offset from the upper rails 54 to accommodate the multiple rolling elements 64, and share a common center of curvature. According to the arrangement of the second conformance mechanism 24b, each of the lower rails 62 is connected to the base plate 28 at an upper pivot point 68 via an upper pivot arm 66. The connection is such that the upper pivot arm 66 rotates relative to the base plate 28 about the upper pivot point 68, which allows the movement of the base plate 28 and thus of the end effector 12 (in Fig. (1 shown) in the second direction of movement 50. Due to the arrangement of the middle section 60 vertically below the end sections 56, the position and configuration of the upper rails 54 and the lower rails 62 cause the end effector 12 to return to a second neutral position 70 relative to the second direction of movement 50 due to gravity in the absence of any further applied force. According to some embodiments, the first conforming mechanism 24a can include a locking device 90, which is arranged, for example, at the pivot point 68, to selectively lock the position of the second conforming mechanism 24b. The locking device can also be, for example, a braking or clamping device that locks the conforming rail 38 to the base rail 30.

[0034] The conformal arrangement 22, which employs the conformance mechanisms 24a and 24b, provides degrees of freedom for the translational motion of the end effector 12 in the first and second directions of motion 42, 50, or combinations thereof, with minimal resistance or applied force required to effect the motion, while constraining the rotational orientation of the end effector 12. Furthermore, the conformal arrangement 22 is self-centering and returns to a neutral equilibrium position under gravitational force in the absence of any other applied forces. Additionally, the structure is configured to support a cantilevered end effector 12, meaning it carries a center of mass at a distance without altering the equilibrium position. The self-centering motion under gravitational force exhibits a constant natural frequency that is independent of the magnitude of the weight of the end effector 12 and any other payloads.

[0035] Some embodiments may include one or more position sensors to determine the positions of the conformity mechanisms 24a, 24b. For example, in Fig. As shown in Figure 2, a rotary sensor 82 can be located on the pivot joint 44 to determine the position of the end effector 12 via the position of the pivot joint 44. Additionally or alternatively, one or more position sensors can include a linear encoder 84, which is arranged on the base rail 30 to determine the position of the conformal rail 38 relative to the base rail 30. As shown in Fig. As shown in Figure 3, one or more sensors 82, 84 can be used in a similar manner on the second conformance mechanism 24b. As shown in Figure 3. Fig.As shown in Figure 1, the conforming arrangement 22 is connected to the robot 80, which includes a robot drive 86 and a controller 88. The controller 88 is operationally connected to one or more sensors 82, 84 and receives feedback from the sensors 82, 84 relating to the position of the conforming mechanisms 24a, 24b. The controller 88 can then instruct the robot drive 86 to position the robot 80 in response to the detected position of the conforming mechanisms 24a, 24b.

Claims

[1] End effector support element (20) for a system (10) comprising: a first conformity mechanism (24a) which includes: two base rails (30), wherein a first base rail (30a) of the two base rails (30) is offset to a second base rail (30b) of the two base rails (30) in a first direction of movement (42) of an end effector (12), wherein each base rail (30a, 30b) has a curved profile; two conformal rails (38), each operationally connected to a corresponding base rail (30a, 30b) of the two base rails (30), each conformal rail (38) having a complementary curved profile to each of the base rails (30a, 30b); and several rolling elements (40) arranged between each base rail (30a, 30b) and each conformal rail (38) to operationally connect the base rail (30a, 30b) to the conformal rail (38); and a position sensor arranged on the first conformance mechanism (24a) to detect a position of the conforming rails (38) relative to the corresponding base rails (30a, 30b); wherein each conformal rail (38) is configured to be symmetrically pivotable connected to the end effector (12) to allow movement of the end effector (12) in the first direction of movement (42). [2] End effector support element (20) according to claim 1, which further comprises a base plate (28) to which the two base rails (30) are attached. [3] End effector support element (20) according to claim 1, wherein the two base rails (30) are configured such that the end effector (12) returns to a neutral position by gravity relative to the first direction of movement (42). [4] End effector support element (20) according to claim 1, wherein the two conformal rails (38) are arranged vertically below the two base rails (30). [5] End effector support element (20) according to claim 1, which further includes a locking mechanism to selectively lock the position of the conformal rails (38) relative to the corresponding base rails (30). [6] End effector support element (20) according to claim 1, wherein the position sensor includes a rotary sensor (82) that detects a rotation of a rotary joint connecting the end effector (12) to the base rail (30a, 30b) or a linear sensor (84) that detects a relative movement of a conformal rail (38) of the two conformal rails (38) with respect to a complementary base rail (30a, 30b) of the two base rails (30). [7] End effector support element (20) according to claim 1, further comprising a second conformity mechanism (24b) comprising: two upper rails (54), wherein a first upper rail of the two upper rails (54) is offset to a second upper rail of the two upper rails (54) in a second direction of movement (50) of the end effector (12), each upper rail having the same curved profile; two lower rails (62), each of which is operationally connected to a corresponding base rail (30a, 30b) of the two upper rails (54), wherein each lower rail (62) has a complementary curved profile to each of the upper rails (54); several rolling elements (64) arranged between each upper rail (54) and each lower rail (62) to operationally connect the upper rail (54) to the lower rail (62); wherein each lower rail (62) is pivotably connected to a first conformance mechanism (24a) to allow movement of the end effector (12) in the second direction of movement (42); and a second position sensor arranged on the second conformance mechanism (24b) to detect a position of the lower rails (62) relative to the corresponding upper rails (54). [8] End effector support element (20) according to claim 7, wherein the second conformity mechanism (24b) is arranged vertically above the first conformity mechanism (24a). [9] End effector support element (20) according to claim 7, wherein the second direction of movement (50) is perpendicular to the first direction of movement (42). [10] Robot system (10) comprising: a robot (80); an end effector (12) which is operationally connected to the robot (80); and an end effector support element (20) according to one of claims 1-9, which operationally connects the end effector (12) to the robot.

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