Parallel link robot and parallel link structure
10427294 ยท 2019-10-01
Assignee
Inventors
Cpc classification
F16H21/46
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H21/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B25J9/0045
PERFORMING OPERATIONS; TRANSPORTING
International classification
F16H21/46
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H21/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
There is provided a parallel link robot that includes a movable section, a plurality of first links, a plurality of connection sections, a plurality of second links, a plurality of first shaft sections, a plurality of third links, a plurality of second shaft sections, and a fixation unit including a plurality of driving sources. The plurality of first links are connected to the plurality of driving sources. The plurality of connection sections are connected to the plurality of first links. The plurality of second links are connected to the plurality of first links via the plurality of connection sections. The plurality of first shaft sections are connected to the plurality of second links. The plurality of third links are connected to the plurality of second links via the plurality of first shaft sections, and to the movable section through the plurality of second shaft sections.
Claims
1. A parallel link robot, comprising: a fixation unit including a plurality of driving sources; a movable section; a plurality of first links connected to the plurality of driving sources; a plurality of connection sections rotatably connected to the plurality of first links; a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections; a plurality of first shaft sections rotatably connected to the plurality of second links; a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and a plurality of second shaft sections, wherein the plurality of third links are rotatably connected to the movable section via the plurality of second shaft sections, the plurality of second shaft sections extends peripherally outward from the movable section, the plurality of driving sources includes parallel output shafts.
2. The parallel link robot according to claim 1, wherein the plurality of third links includes a pair of third links, and the pair of third links is connected to the movable section via one second shaft section of the plurality of second shaft sections.
3. The parallel link robot according to claim 2, wherein a length of each of the pair of third links is different.
4. The parallel link robot according to claim 1, wherein a first virtual plane at a first distance from the fixation unit, the first virtual plane includes connection positions of the plurality of first shaft sections in the plurality of second links, a second virtual plane is at a second distance from the fixation unit, the second virtual plane includes connection positions of the plurality of second shaft sections in the movable section, and the first distance is greater than the second distance.
5. The parallel link robot according to claim 1, wherein at least one of the plurality of third links includes an L-shaped block.
6. The parallel link robot according to claim 1, wherein the fixation unit further includes a support element that is configured to support the plurality of driving sources such that the parallel output shafts are non-coaxial.
7. The parallel link robot according to claim 6, wherein the support element includes one of a supporting plate or a supporting frame; one of the supporting plate or the supporting frame is configured such that the parallel output shafts passes therethrough, and one of the supporting plate or the supporting frame is between main bodies of the plurality of driving sources.
8. The parallel link robot according to claim 1, further comprising at least one set of arms, wherein the at least one set of arms includes the plurality of first links, the plurality of second links, and the plurality of third links, the plurality of first links includes two first links, the plurality of second links includes two second links, and the plurality of third links includes a two third links.
9. The parallel link robot according to claim 1, further comprising a plurality of sets of arms, wherein the plurality of sets of arms includes the plurality of first links, the plurality of second links, and the plurality of third links, the plurality of sets of arms is at equal intervals around a virtual center axis, and the virtual center axis links a center of the fixation unit with a center of the movable section.
10. The parallel link robot according to claim 1, wherein the plurality of second shaft sections are at an oblique angle to a virtual plane, and the virtual plane includes positions at which the second shaft sections are connected to the movable section.
11. The parallel link robot according to claim 9, wherein the plurality of second shaft sections is at a specific distance from the fixation unit in a direction of the virtual center axis as the plurality of second shaft sections extends peripherally outward from the movable section.
12. A parallel link robot, comprising: a fixation unit including a plurality of driving sources; wherein the plurality of driving sources includes parallel output shafts; a movable section; a plurality of first links connected to the plurality of driving sources; a plurality of connection sections rotatably connected to the plurality of first links; a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections; a plurality of first shaft sections rotatably connected to the plurality of second links; a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and a plurality of second shaft sections with the plurality of third links being rotatably connected to the movable section, wherein the plurality of second links are connected to the movable section via the plurality of third links such that end portions of the plurality of second links, are at positions offset from the plurality of second shaft sections, and the positions being offset are peripherally outward from the movable section.
13. A parallel link structure, comprising: a movable section; a plurality of first links connected to a plurality of driving sources via parallel output shafts, wherein the plurality of driving sources includes the parallel output shafts; a plurality of connection sections rotatably connected to the plurality of first links; a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections; a plurality of first shaft sections rotatably connected to the plurality of second links; a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and a plurality of second shaft sections, wherein the plurality of third links are rotatably connected to the movable section via the plurality of second shaft sections, and the plurality of second shaft sections extends peripherally outward from the movable section.
14. A parallel link structure, comprising: a plurality of first links connected to a plurality of driving sources via a parallel output shafts, wherein the plurality of driving sources includes the parallel output shafts, a plurality of second links rotatably connected to the plurality of first links; a plurality of first shaft sections rotatably connected to the plurality of second links; a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and a plurality of second shaft sections with the plurality of third links being rotatably connected to a movable section, wherein the plurality of second links are connected to the movable section via the plurality of third links such that end portions of the plurality of second links, are at positions offset from the plurality of second shaft sections, and the positions being offset are peripherally outward from the movable section.
15. A parallel link robot, comprising: a fixation unit including a plurality of driving sources; a movable section; a plurality of first links connected to the plurality of driving sources; a plurality of connection sections rotatably connected to the plurality of first links; a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections; a plurality of first shaft sections rotatably connected to the plurality of second links; a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and a plurality of second shaft sections, wherein the plurality of third links are rotatably connected to the movable section via the plurality of second shaft sections, the plurality of second shaft sections extends peripherally outward from the movable section, the plurality of third links include a plurality of pairs of third links, each of the plurality of pairs of third links includes two third links, and the plurality of driving sources are configured to independently drive each of the plurality of pairs of third links.
Description
BRIEF DESCRIPTION OF DRAWINGS
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MODE(S) FOR CARRYING OUT THE INVENTION
(13) Hereinafter, embodiments of the present technology will be described with reference to the drawings.
1. First Embodiment
(14) (1) Overall Configuration of Parallel Link
(15)
(16) Note that, in
(17) (2) Configuration of Fixation Unit
(18)
(19) The fixation unit 20 includes a plurality of motors (driving sources) 15 and a support 12 that supports the motors 15. The support 12 includes three supporting plates 12a. The three supporting plates 12a are arranged at predetermined angular intervals, here, at 120 intervals around the z-axis. Each of the supporting plates 12a may be formed integrally with the top plate 11 or may have a structure that is mounted and fixed on the top plate 11. The supporting plates 12a may be replaced by a frame-like member (supporting frame).
(20) As shown in
(21) Driving of each of the six motors 15 is individually controlled by a control unit (not shown).
(22) As shown in
(23) Note that members other than the supporting plates 12a and the main bodies 16 of the motors 15 are not shown in
(24) As described above, the motors 15 are arranged such that the output shafts 17 (17a, 17b) of the set of motors 15a and 15b are non-coaxial. Thus, a degree of freedom of arrangement for the motors 15 can be increased in comparison with coaxial output shafts. In particular, in this embodiment, the set of motors 15a and 15b is mounted on the single supporting plate 12a, and hence relative arrangement accuracy of the set of motors 15a and 15b, that is, parallelism accuracy (linearity) of the output shafts 17a and 17b can be enhanced. With this, driving accuracy and positioning accuracy of the parallel link structure 50 connected to the output shafts 17 can be enhanced.
(25) (3) Configuration of Parallel Link Structure
(26) Next, a configuration of the parallel link structure 50 connected to the fixation unit 20 will be described. Hereinafter, all configurations of the links and the like driven by the three sets of motors 15 are substantially identical, and hence a link structure driven by connection of the set of motors 15a and 15b will be mainly described. Further, the entire link structure will be described if necessary.
(27) The first links 41 parallel as viewed in the z-axis direction are connected and fixed on the output shafts 17a and 17b of the set of motors 15a and 15b (see
(28) As an example, the connection section 45 includes a rotation shaft 45a and a connection block 45b. The rotation shaft 45a is rotatably connected to an end portion of the first link 41. The connection block 45b is fixed on the rotation shaft 45a. One ends of the second links 42 are rotatably connected to the connection block 45b. With this, degrees of freedom of rotation are provided around two axes in the connection section 45.
(29) The connection section 45 includes a bearing 45c. This bearing makes the second link 42 rotatable. The rotation shaft 45a may also be connected to the first link 41 via the bearing or a configuration in which a pin serving as the rotation shaft 45a is inserted into a hole formed in the first link 41 may be employed.
(30) The set of second links 42a and 42b (see
(31)
(32) The other end of the second link 42 includes an end block 421. The end block 421 has an L-shape including a first side portion 422 and a second side portion 423, for example. A main body of the second link 42 is mounted and fixed on the first side portion 422 and a third link 43 is rotatably connected to the second side portion 423 via a rotation shaft 46 (first shaft section). Since the end block 421 has an L-shape, the rotation shaft 46 extends in a direction substantially orthogonal to an axis extending along a longitudinal direction of the second link 42.
(33) For example, the third link 43 has an L-shaped block shape and includes a first side portion 431 and a second side portion 432. The third link 43 is, at the first side portion 431 thereof, connected to the second side portion 423 of the end block 421 via the rotation shaft 46. The third links 43 are, at the second side portions 432 thereof, connected through a common rotation shaft 47 (second shaft section) and the rotation shaft 47 is rotatably connected to the movable plate 55. That is, each of the third links 43 is rotatably connected to the movable plate 55 via the rotation shaft 47.
(34) In this manner, a pair of third links 43A and 43B (see
(35) With such a configuration, the third link 43 turns in a specific plane with respect to the movable plate 55. The shape of the movable plate 55, the length of the third link 43, and the like are suitably designed such that the pair of third links 43A and 43B and the movable plate 55, which are coaxially connected through the rotation shaft 47, do not interfere with each other when the movable plate 55 takes any posture.
(36) Further, the third links 43 are favorably set to be short. It is because there is a fear that too long third links 43 may interfere with the second links 42, which reduces a range of rotational motion. As a matter of course, too short third links 43 are also not suitable and there is an optimal-length range. In particular, in this embodiment, the pair of third links 43A and 43B connected through the common rotation shaft 47 has different lengths. With this, the range of rotational motion can be made as large as possible while eliminating interference.
(37) In addition, forming the third link 43 in an L-shape also contributes to the increase in range of rotational motion and the elimination of interference.
(38) The movable plate 55 has a schematic triangular shape, for example, and has a shape obtained by cutting three apexes of the triangle. As shown in
(39) The home position of the movable plate 55, that is, the home position of the parallel link structure 50 is the position of the parallel link structure 50 shown in
(40) (a) Presence of three connection positions (hereinafter, referred to as plate connection positions), at which the rotation shafts 47 are connected to the third links 43, in the x-y plane,
(41) (b) Parallelism between an arrangement direction of the set of motors 15a and 15b and an arrangement direction of two plate connection positions corresponding to this set of motors 15a and 15b (corresponding via first links 41, second links 42, and third links 43), and
(42) (c) Alignment between a center position of the six motors 15 and a center position of the movable plate 55 as viewed in the z-axis direction.
(43) The above-mentioned configuration of the parallel link robot 100 makes it possible to provide the parallel link structure 50 in which three sets of arms are arranged at equal intervals around a virtual center axis D (see
(44) Further, with the above-mentioned configuration, this parallel link structure 50 is characterized in that, when it is at the home position, a virtual plane including connection positions of the rotation shafts 46 in the second links 42 is located farther from the fixation unit 20 than a virtual plane including the plate connection positions.
(45) (4) Operation of Parallel Link Robot
(46) Next, an operation of the parallel link robot 100 will be described. Here, descriptions on translational motions in three-axis (x-, y-, and z-axis) directions will be omitted and only rotations around the three axes (yaw, pitch, and roll) will be described.
(47) (4-1) Rotation Around X-Axis (or Y-Axis)
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(49) (4-1) Rotation Around Z-Axis
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(51) (4-2) Combined Motion
(52) With this parallel link robot 100, at least one of the translational motions along the three axes can also be combined with at least one of the rotations around the three axes as described above. Thus, the parallel link robot 100 is movable in an arbitrary direction by an arbitrary angle with six degrees of freedom.
(53) (5) Conclusion
(54) As described above, in this embodiment, the rotation shafts 47 extend peripherally outward from the movable section 55, the third links 43 are connected to the rotation shafts 47, and the second links 42 are connected to the third links 43. Therefore, the end blocks 421 of the second links 42 are arranged at positions offset (positions deviated) from the positions of the rotation shaft 47. With such a configuration, the end blocks 421 of the second links 42 are separated from a movable region of the movable plate 55. Therefore, interference between the end blocks 421 and the movable plate 55 can be avoided and a range of rotational motion which is as large as possible can be provided with a relatively simple structure.
(55) For example, if a universal-joint or ball-joint structure is used as a connection structure between the second links 42 and the movable plate 55, the range of rotational motion of the movable plate 55 is about 30 at most due to the structure thereof. Thus, the range is smaller in comparison with the structure in which the third links 43 are provided as in this embodiment.
(56) Further, with the universal joint, backlash may occur due to the structure thereof, and hence the driving accuracy or positioning accuracy of the movable plate 55 is lowered.
(57) Paper: Proposal of Link Composition for Rotational Parallel Mechanism with Pin Joints and Investigation of Movable Area (by Kazuya OKAWA, Yoshihiro Okamura) has disclosed a composite-type parallel link structure. Here, the composite type is a hybrid type including both of an inwardly bent type structure in which links are inwardly bent and an outwardly bent type structure in which links are outwardly bent. The parallel link structure 50 according to the present technology is the outwardly bent type structure.
(58) In accordance with the paper, the composite-type parallel link structure described in the paper above is capable of taking a posture of 60. However, it is a composite type, and hence there is a fear that backlash may more frequently occur and highly accurate motions will be difficult. On the contrary, the parallel link structure 50 according to this embodiment is capable of suppressing occurrence of backlash, which makes highly accurate motions possible.
2. Second Embodiment
(59)
(60) The parallel link robot 200 includes a fixation unit 70 and a parallel link structure 80. In
(61)
(62) As shown in
(63) For example, the second shaft sections are provided such that the second shaft sections are spaced away from the fixation unit 70 in a direction of the center axis D (see
(64) A point at which the connection section 45 (see
3. Various Other Embodiments
(65) The present technology is not limited to the above-mentioned embodiments and various other embodiments can be implemented.
(66) The motors 15 of the fixation unit 20 are not limited to the arrangement as in the first embodiment and various modifications can be made. For example, instead of mounting the set of motors 15 on the single supporting plates 12a, a configuration in which the set of motors 15 may be mounted on two supporting plates 12a may be employed (as in second embodiment). Alternatively, the fixation unit according to the second embodiment may have the configuration as in the first embodiment. Alternatively, the set of motors 15 is not necessarily limited to the embodiment in which the directions of those motors are 180 degrees different from each other.
(67) Linear motors, not rotation motors may be used as the motors 15.
(68) In the above, the directions in which the rotation shafts 47 extend are the radial directions of the movable plate 55 (105). However, they do not necessarily need to be the radial directions (that is, directions orthogonal to tangents to outer periphery of movable plate). Any direction can be used therefor as long as they can extend in a spreading manner. That is, the directions in which the rotation shafts 47 extend do not need to be perpendicular to the tangents.
(69) The shape of the movable plate 55 or 105 is not limited to the schematic triangle, the three-piece shape as in each of the above-mentioned embodiments. The movable plate 55 or 105 may have an arbitrary shape in a manner that depends on the range of motion.
(70) The shape of the end block 421 of the second link 42 is not limited to the L-shape and may be a U-shape or an inverse C-shape. Further, the shape of the end block 421 is not limited to the right-angle L-shape and may be a shape having an angle slightly different from a right angle. Similarly, the shape of the third link 43 is also not limited to the L-shape. The same applies to the second embodiment.
(71) In the above, the rotation shaft 47 through which the third links 43 are connected to the movable plate 55 is the rotation shaft common to the pair of third links. However, the third links 43 may be individually connected to the movable plate 55 via rotation shafts (as in second embodiment). In the second embodiment, the pair of third links 93A and 93B may be connected to the movable plate through a common single second shaft section as in the first embodiment.
(72) As shown in
(73) The parallel link robot according to the present technology is used as an assembly robot and also used for other purposes as follows. For example, the parallel link robot according to the present technology is used for box packing work of products, inspection of products, and evaluation of response accuracy of touch panels (e.g., hand writing inputs). For inspection of products, the parallel link robot is capable of sensing products at various angles when a sensor such as a camera is mounted on the movable plate, for example.
(74) Alternatively, the parallel link robot according to the present technology is also applicable to a multi-axis table, a medical manipulator, and the like.
(75) At least two feature parts of the feature parts of the above-mentioned embodiments can also be combined.
(76) It should be noted that the present technology may also take the following configurations.
(77) (1)
(78) A parallel link robot, including:
(79) a fixation unit including a plurality of driving sources;
(80) a movable section for operation;
(81) a plurality of first links connected to the plurality of driving sources;
(82) a plurality of connection sections rotatably connected to the plurality of first links;
(83) a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections;
(84) a plurality of first shaft sections rotatably connected to the plurality of second links;
(85) a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and
(86) a plurality of second shaft sections through which the plurality of third links are rotatably connected to the movable section, the plurality of second shaft sections extending peripherally outward from the movable section.
(87) (2)
(88) The parallel link robot according to (1), in which
(89) the plurality of third links constitute a pair of third links constituted of two third links, and
(90) the pair of third links is connected to the movable section through one second shaft section of the plurality of second shaft sections.
(91) (3)
(92) The parallel link robot according to (2), in which
(93) the pair of third links has different lengths.
(94) (4)
(95) The parallel link robot according to any one of (1) to (3), in which
(96) the plurality of second links, the plurality of third links, and the movable section are arranged such that a virtual plane including connection positions of the plurality of first shaft sections in the plurality of second links is located farther from the fixation unit than a virtual plane including connection positions of the plurality of second shaft sections in the movable section.
(97) (5)
(98) The parallel link robot according to any one of (1) to (4), in which
(99) at least one of the plurality of third links is constituted of an L-shaped block.
(100) (6)
(101) The parallel link robot according to (1), in which
(102) the plurality of driving sources include a set of driving sources including a set of parallel output shafts.
(103) (7)
(104) The parallel link robot according to (6), in which
(105) the fixation unit includes a support that supports the set of driving sources such that output shafts of the set of driving sources are non-coaxial.
(106) (8)
(107) The parallel link robot according to (7), in which
(108) the support includes a supporting plate or a supporting frame configured such that the output shafts pass therethrough, the supporting plate or the supporting frame being provided between main bodies of the set of driving sources.
(109) (9)
(110) The parallel link robot according to (1), in which
(111) the plurality of first links include a set of first links constituted of two first links,
(112) the plurality of second links include a set of second links constituted of two second links,
(113) the plurality of third links include a set of third links constituted of two third links, and
(114) the set of first links, the set of second links, and the set of third links constitute one ore more sets of arms.
(115) (10)
(116) The parallel link robot according to (9), in which
(117) the plurality of sets of arms are arranged at equal intervals around a virtual center axis linking a center of the fixation unit with a center of the movable section.
(118) (11)
(119) The parallel link robot according to (1), in which
(120) the plurality of second shaft sections are provided obliquely to a virtual plane including positions at which the second shaft sections are connected to the movable section.
(121) (12)
(122) The parallel link robot according to (11), in which
(123) the plurality of second shaft sections are provided such that the plurality of second shaft sections are spaced away from the fixation unit in a direction of a virtual center axis linking a center of the fixation unit with a center of the movable section as the plurality of second shaft sections extend peripherally outward from the movable section.
(124) (13)
(125) A parallel link robot, including:
(126) a fixation unit including a plurality of driving sources;
(127) a movable section for operation;
(128) a plurality of first links connected to the plurality of driving sources;
(129) a plurality of connection sections rotatably connected to the plurality of first links;
(130) a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections;
(131) a plurality of first shaft sections rotatably connected to the plurality of second links;
(132) a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and
(133) a plurality of second shaft sections with the plurality of third links being rotatably connected to the movable section, in which
(134) the plurality of second links are connected to the movable section via the plurality of third links such that end portions of the plurality of second links, to which the plurality of first shaft sections are connected, are arranged at positions offset from the plurality of second shaft sections peripherally outward from the movable section.
(135) (14)
(136) A parallel link structure, including:
(137) a movable section for operation;
(138) a plurality of first links connected to the plurality of driving sources;
(139) a plurality of connection sections rotatably connected to the plurality of first links;
(140) a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections;
(141) a plurality of first shaft sections rotatably connected to the plurality of second links;
(142) a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and
(143) a plurality of second shaft sections through which the plurality of third links are rotatably connected to the movable section, the plurality of second shaft sections extending peripherally outward from the movable section.
(144) (15)
(145) A parallel link structure for a robot, the robot including a movable section for operation, a plurality of first links connected to the plurality of driving sources, a plurality of connection sections rotatably connected to the plurality of first links, and a plurality of second links rotatably connected to the plurality of first links via the plurality of connection sections, the parallel link structure including:
(146) a plurality of first shaft sections rotatably connected to the plurality of second links;
(147) a plurality of third links rotatably connected to the plurality of second links via the plurality of first shaft sections; and
(148) a plurality of second shaft sections with the plurality of third links being rotatably connected to the movable section, in which
(149) the plurality of second links are connected to the movable section via the plurality of third links such that end portions of the plurality of second links, to which the plurality of first shaft sections are connected, are arranged at positions offset from the plurality of second shaft sections peripherally outward from the movable section. 12 support 12a supporting plate 15 motor 17 output shaft 20 fixation unit 41 first link 42 second link 43, 93 third link 45 connection section 46, 47 rotation shaft 50, 80 parallel link structure 55, 105 movable plate 100, 200 parallel link robot