# US 11,993,325 B2 · Legged mobile robot, leg control method, and program storage medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,325 B2 - Document ID: US11993325B2 - Status: Granted - Kind: B2 - Application number: 17/369,695 - Filed: 2021-07-07 - Published: 2022-01-20 - Granted: 2024-05-28 - Earliest claimed: 2020-07-16 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Takeharu Kitagawa - Web page: https://patentgrep.com/patent/US11993325B2 ## CPC - B62D 57/032: with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract A legged mobile robot includes at least two legs. The legs are movable in a front-rear direction of the legged mobile robot. Each of distal end portions of the legs is provided with a plurality of protrusions. Protruding directions of the protrusions are a plurality of directions including a lateral direction intersecting with the front-rear direction. The protrusions can come into contact with a moving surface on which the legs move. Further, the legged mobile robot includes a drive device that displaces each of the protrusions up down with respect to a sole in contact with the moving surface in the leg. The legged mobile robot further includes a control device that controls movement of the protrusions. ## Claims ### Claim 1 A legged mobile robot comprising: a plurality of legs movable in a front-rear direction, each of the plurality of legs including a sole with a recess shape that is open to a moving surface on which the plurality of legs move; a plurality of protrusions respectively protruding in a plurality of directions including at least a lateral direction intersecting with the front-rear direction from a distal end portion of each of the plurality of legs, and capable of coming into contact with the moving surface; a drive device configured to displace each of the protrusions up and down with respect to the sole of each of the legs, the sole being a part in contact with the moving surface; and a control device configured to control movements of each of the protrusions by controlling the drive device. ### Claim 2 (depends on 1) The legged mobile robot according to claim 1, wherein the control device controls the drive device in such a way that, when at least one of the legs of the plurality of legs lands on the moving surface after moving in a direction away from the moving surface, no force is applied from the drive device to the protrusions of the landing leg, and the control device controls the drive device to lock movements of the protrusions of the landing leg after the protrusions follow a shape of the moving surface by the landing of the leg. ### Claim 3 (depends on 1) The legged mobile robot according to claim 1, wherein the control device controls the drive device in such a way that, when at least one of the legs of the plurality of legs moves in a direction away from the moving surface, the protrusions of the moving leg press the moving surface. ### Claim 4 (depends on 1) The legged mobile robot according to claim 1, wherein the protrusions have a planar portion that is in planar contact with the moving surface. ### Claim 5 (depends on 1) The legged mobile robot according to claim 1, wherein the number of the legs is two, and the legged mobile robot performs bipedal walking with the two legs. ### Claim 6 A leg control method comprising: by a computer configuring a control device of a legged mobile robot including a plurality of legs movable in a front-rear direction, each of the plurality of legs including a sole with a recess shape that is open to a moving surface on which the plurality of legs move; a plurality of protrusions respectively protruding in a plurality of directions including at least a lateral direction intersecting with the front-rear direction from a distal end portion of each of the plurality of legs, and capable of coming into contact with the moving surface, a drive device configured to displace each of the protrusions up and down with respect to the sole of each of the legs, the sole being a part in contact with the moving surface, and the control device configured to control movements of each of the protrusions by controlling the drive device, controlling the drive device in such a way that, when at least one of the legs of the plurality of legs lands on the moving surface after moving in a direction away from the moving surface, no force is applied from the drive device to the protrusions of the landing leg; and controlling the drive device to lock movements of the protrusions of the landing leg after the protrusions follow a shape of the moving surface by the landing of the leg. ### Claim 7 A non-transitory program storage medium storing a computer program for causing a computer configuring a control device of a legged mobile robot including a plurality of legs movable in a front-rear direction, each of the plurality of legs including a sole with a recess shape that is open to a moving surface on which the plurality of legs move; a plurality of protrusions respectively protruding in a plurality of directions including at least a lateral direction intersecting with the front-rear direction from a distal end portion of each of the plurality of legs, and capable of coming into contact with the moving surface, a drive device configured to displace each of the protrusions up and down with respect to the sole of each of the legs, the sole being a part in contact with the moving surface, and the control device configured to control movements of each of the protrusions by controlling the drive device, to execute: controlling the drive device in such a way that, when at least one of the legs of the plurality of legs lands on the moving surface after moving in a direction away from the moving surface, no force is applied from the drive device to the protrusions of the landing leg; and controlling the drive device to lock movements of the protrusions of the landing leg after the protrusions follow a shape of the moving surface by the landing of the leg.