US 12,285,864 B2Granted

Link actuation device and method for driving link actuation device

AssigneesKyushu Institute of Technology, Ntn Corporation

InventorsAkihiro Hayashi, Hirofumi Fukumaru, Toshiki Takaki

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Abstract

A link actuation device includes a proximal link hub, a distal link hub, link mechanisms that couple the link hubs, an actuator, and a control device. The actuator includes motors provided for link mechanisms, respectively. The control device stores a map in which drive command values for each of the motors corresponding to a plurality of discrete positions within a movable range of the distal link hub are stored. Upon receipt of a command value for movement to a position that coincides with none of the plurality of positions within the movable range, the control device determines a drive command value for each of the motors by interpolating a region surrounded by four points at the plurality of positions on the map using a polynomial curved surface formula.

Claims4

Dependent claims

A link actuation device comprising:

a first link hub adjacent to a proximal end;
a second link hub adjacent to a distal end;
at least three link mechanisms that couple the first link hub and the second link hub;
a drive device that drives the at least three link mechanisms;
and
a control device that controls the drive device, wherein
the drive device includes motors provided for the at least three link mechanisms, respectively,
each of the at least three link mechanisms includes
a first end link member rotatably coupled to the first link hub,
a second end link member rotatably coupled to the second link hub, and
a center link member rotatably coupled to both the first end link member and the second end link member,
in the at least three link mechanisms,
at least three center axes of revolute pairs of the first link hub and the first end link members and a center axis of a revolute pair of one end of each of the center link members intersect at a first link hub center point, and
at least three center axes of revolute pairs of the second link hub and the second end link members and a center axis of a revolute pair of an other end of each of the center link members intersect at a second link hub center point,
the control device stores a map in which drive command values for each of the motors corresponding to a plurality of discrete positions within a movable range of the second link hub are stored, and
upon receipt of a command value for movement to a position that coincides with none of the plurality of positions within the movable range, the control device determines a drive command value for each of the motors by interpolating a region surrounded by four points at the plurality of positions on the map using a polynomial curved surface formula.

13 more elements

A method for driving a link actuation device,

the link actuation device including
a first link hub adjacent to a proximal end,
a second link hub adjacent to a distal end,
at least three link mechanisms that couple the first link hub and the second link hub, and
a drive device that drives the at least three link mechanisms, the drive device including motors provided for the at least three link mechanisms, respectively,
each of the at least three link mechanisms including
a first end link member rotatably coupled to the first link hub,
a second end link member rotatably coupled to the second link hub, and
a center link member rotatably coupled to both the first end link member and the second end link member, and
in the at least three link mechanisms,
at least three center axes of revolute pairs of the first link hub and the first end link members and a center axis of a revolute pair of one end of each of the center link members intersecting at a first link hub center point, and
at least three center axes of revolute pairs of the second link hub and the second end link members and a center axis of a revolute pair of an other end of each of the center link members intersecting at a second link hub center point,
the method comprising:
generating and storing a map in which drive command values for each of the motors corresponding to a plurality of discrete positions within a movable range of the second link hub are stored;
receiving a target movement position of the second link hub;
interpolating a region surrounded by four points at the plurality of positions on the map using a polynomial curved surface formula in a case where the target movement position coincides with none of the plurality of positions within the movable range;
determining a drive command value for each of the motors using the map subjected to the interpolation;
and
driving each of the motors using the command value determined for each of the motors.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/181,291Filed 9 Mar 2023
Priority: JP 2022-03828911 Mar 2022
Published: US 2023/0286138 A114 Sep 2023
Granted: 29 Apr 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B25J 9/1605
Characterised by the control system, structure, architecture: simulation of manipulator lay-out, design, modelling of manipulator
B25J 9/0048
With kinematics chains having a rotary joint at the base: with kinematics chains of the type rotary-rotary-rotary
B25J 9/1615
Program controls: characterised by special kind of manipulator, e.g. planar, scara, gantry, cantilever, space, closed chain, passive/active joints…
B25J 9/1623
Characterised by special kind of manipulator, e.g. planar, scara, gantry, cantilever, space, closed chain, passive/active joints and tendon…