Wheel device and mobile robot device comprising same
A wheel device includes: a plurality of wing members configured to rotate around a central axis, wherein each wing member of the plurality of wing members may include an outer circumferential surface and each wing member of the plurality of wing members is configured to be movable to a first position in which the respective outer circumferential surfaces combine to form a circle, and to a second position in which an end of each outer circumferential surface is rotated away from the central axis of the wheel device; a deforming device configured to move each wing member of the plurality of wing members to the first position or the second position; a plurality of rollers provided on the respective outer circumferential surfaces of the plurality of wing members, wherein each roller of the plurality of rollers has a rotation axis that is not parallel to the central axis; and a braking device including a brake pad configured to contact one or more rollers of the plurality of rollers when the plurality of wing members are in the second position and to separate from the plurality of rollers when the plurality of wing members are in the first position.
1 . A wheel device comprising:
a plurality of wing members configured to rotate around a central axis, wherein each wing member of the plurality of wing members comprises an outer circumferential surface and each wing member of the plurality of wing members is configured to be movable to a first position in which the respective outer circumferential surfaces combine to form a circle, and to a second position in which each outer circumferential surface is rotated away from the central axis of the wheel device;
a deforming device configured to move each wing member of the plurality of wing members to the first position or the second position;
a plurality of rollers provided on the respective outer circumferential surfaces of the plurality of wing members, wherein each roller of the plurality of rollers has a rotation axis that is not parallel to the central axis; and
a braking device comprising a brake pad configured to contact one or more rollers of the plurality of rollers when the plurality of wing members are in the second position and to separate from the plurality of rollers when the plurality of wing members are in the first position.
2 . The wheel device of claim 1 , wherein the braking device further comprises a support link configured to rotatably connect the brake pad to a wing member from among the plurality of wing members.
3 . The wheel device of claim 2 , wherein the braking device further comprises a first torsion spring connecting the support link with the wing member.
4 . The wheel device of claim 2 , wherein the braking device further comprises a braking motor configured to rotate the support link.
5 . The wheel device of claim 1 , wherein the brake pad is disposed parallel to the outer circumferential surface of a wing member from among the plurality of wing members.
6 . The wheel device of claim 1 , wherein the brake pad comprises a rubber material.
7 . The wheel device of claim 1 , wherein each wing member of the plurality of wing members further comprises a first point positioned at an innermost end thereof, a second point positioned between one end of the outer circumferential surface and the first point, and a third point positioned at another end of the outer circumferential surface, and
wherein the deforming device comprises:
a first spoke connecting the respective first points of the plurality of wing members with each other;
a plurality of links each connecting the respective second point of a first wing member among the plurality of wing members and the third point of a second wing member among the plurality of wing members that is adjacent to the first wing member; and
a second spoke connecting respective intermediate regions of the plurality of links with one another.
8 . The wheel device of claim 7 , wherein the deforming device further comprises:
a first drive motor configured to rotate the first spoke; and
a second drive motor configured to rotate the second spoke.
9 . The wheel device of claim 7 , wherein the braking device further comprises:
a first braking link integrally formed with the first spoke; and
a second braking link having a first end rotatably connected to a wing member among the plurality of wing members and disposed on a rotational path of the first braking link, and
wherein a second end of the second braking link is configured to press the brake pad into contact with one or more of the plurality of rollers when the second braking link is pressed and rotated by the first braking link.
10 . The wheel device of claim 9 , wherein the first braking link extends from the first spoke away from the central axis.
11 . The wheel device of claim 9 , wherein the braking device further comprises a torsion spring connecting the wing member among the plurality of wing members to the first end of the second braking link.
12 . A mobile robot device comprising:
a base; and
a plurality of wheel devices installed on a lower portion of the base,
wherein each wheel device of the plurality of wheel devices comprises:
a plurality of wing members configured to rotate around a central axis, wherein each wing member of the plurality of wing members comprises an outer circumferential surface and each wing member of the plurality of wing members is configured to be movable to a first position in which the respective outer circumferential surfaces combine to form a circle, and in a second position in which each outer circumferential surface is rotated away from the central axis of the wheel device;
a deforming device configured to move each wing member of the plurality of wing members to the first position or the second position;
a plurality of rollers provided on the respective outer circumferential surfaces of the plurality of wing members, wherein each roller of the plurality of rollers has a rotation axis that is not parallel to the central axis; and
a braking device comprising a brake pad configured to contact one or more rollers of the plurality of rollers when the plurality of wing members are in the second position and to separate from the plurality of rollers when the plurality of wing members are in the first position.
13 . The mobile robot device of claim 12 , further comprising:
an obstacle detection sensor; and
at least one processor configured to:
identify, based on a sensing value obtained via the obstacle detection sensor, a presence of an obstacle in front of the mobile robot device, and
based on identifying the presence of the obstacle in front of the mobile robot device, cause each respective deforming device to move the plurality of wing members of each wheel device of the plurality of wheel devices to the second position.
14 . The mobile robot device of claim 13 , wherein for each respective wheel device among the plurality of wheel devices, the braking device further comprises a support link configured to rotatably connect the brake pad to a wing member from among the plurality of wing members.
15 . The mobile robot device of claim 14 , wherein for each respective wheel device among the plurality of wheel devices, the braking device further comprises a braking motor configured to rotate the support link, and
wherein the at least one processor is further configured to, for each respective wheel device among the plurality of wheel devices, cause the braking motor to rotate the support link away from the central axis based on the identifying the presence of the obstacle in front of the mobile robot device.