US 9,789,607 B1Granted

Achieving a target gait in a legged robot based on steering commands

AssigneeGoogle Inc.

InventorEric Whitman

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Abstract

Based on input steering commands, a legged robot may select a target gait. Based on the target gait, the legged robot may obtain a list of gait controllers. Each gait controller may define a gait of the legged robot, and include validity tests and steering commands. The legged robot may apply a cost function to the gait controllers, where the cost for a gait controller is based on a difference between the steering commands of the gait controller and the input steering commands, and a proximity of the legged robot to obstacles should the legged robot operate according the gait controller. The legged robot may reorder the list in increasing magnitude of the cost function, and traverse the list until a validity test associated with a particular gait controller passes. The legged robot may actuate its legs according to the steering commands of the particular gait controller.

Claims20

Dependent claims

A method comprising:

obtaining, by a legged robot, input steering commands;
in response to obtaining the input steering commands, selecting, by the legged robot, a target gait for the legged robot, wherein the legged robot includes leg members and leg joints;
based on the target gait, obtaining, by the legged robot, an ordered list of gait controllers, wherein the gait controllers in the ordered list define respective gaits of the legged robot, and include respective validity tests and output parameters for the respective gaits, and wherein the output parameters include respective steering commands;
applying, by the legged robot, a cost function to the gait controllers in the ordered list, wherein the cost function assigns respective costs to each gait controller, wherein a cost for a given gait controller is based on a difference between the steering commands of the given gait controller and the input steering commands, and a proximity of the legged robot to one or more obstacles should the legged robot operate according a given gait of the given gait controller for a pre-defined period of time;
reordering, by the legged robot, the ordered list in increasing magnitude of the cost function;
traversing, by the legged robot, the ordered list in order until a validity test associated with a particular gait controller passes;
and
actuating, by the legged robot, the leg members and leg joints according to output parameters of the particular gait controller.

5 more elements

An article of manufacture including a non-transitory computer-readable medium, having stored thereon program instructions that, upon execution by a computing device, cause the computing device to perform operations comprising:

obtaining input steering commands for a legged robot;
in response to obtaining the input steering commands, selecting a target gait for the legged robot, wherein the legged robot includes leg members and leg joints;
based on the target gait, obtaining an ordered list of gait controllers, wherein the gait controllers in the ordered list define respective gaits of the legged robot, and include respective validity tests and output parameters for the respective gaits, and wherein the output parameters include respective steering commands;
applying a cost function to the gait controllers in the ordered list, wherein the cost function assigns respective costs to each gait controller, wherein a cost for a given gait controller is based on a difference between the steering commands of the given gait controller and the input steering commands, and a proximity of the legged robot to one or more obstacles should the legged robot operate according a given gait of the given gait controller for a pre-defined period of time;
reordering the ordered list in increasing magnitude of the cost function;
traversing the ordered list in order until a validity test associated with a particular gait controller passes;
and
actuating the leg members and leg joints according to output parameters of the particular gait controller.

5 more elements

A legged robot comprising:

leg members connected by leg joints;
a processor;
and
memory containing program instructions that, when executed by the processor, cause the legged robot to perform operations comprising:
obtaining input steering commands;
in response to obtaining the input steering commands, selecting a target gait for the legged robot;
based on the target gait, obtaining an ordered list of gait controllers, wherein the gait controllers in the ordered list define respective gaits of the legged robot, and include respective validity tests and output parameters for the respective gaits, and wherein the output parameters include respective steering commands;
applying a cost function to the gait controllers in the ordered list, wherein the cost function assigns respective costs to each gait controller, wherein a cost for a given gait controller is based on a difference between the steering commands of the given gait controller and the input steering commands, and a proximity of the legged robot to one or more obstacles should the legged robot operate according a given gait of the given gait controller for a pre-defined period of time;
reordering the ordered list in increasing magnitude of the cost function;
traversing the ordered list in order until a validity test associated with a particular gait controller passes;
and
actuating the leg members and leg joints according to output parameters of the particular gait controller.

9 more elements

Dependencies are inferred from the claim text.