Achieving a Target Gait Behavior in a Legged Robot

A legged robot comprising:

• leg members connected by leg joints;
• one or more sensors;
• a processor in communication with the one or more sensors;
• and
• a non-transitory computer-readable medium in communication with the processor and storing instructions, that when executed by the processor, cause the processor to perform operations comprising:
• receiving, at a processor of a legged robot, sensor information from the one or more sensors;
• determining an instantaneous state of the legged robot based on the sensor information, the instantaneous state comprising a velocity of the legged robot and a current gait of the legged robot;
• determining a target gait for operating the legged robot on a ground surface;
• obtaining an ordered list of gait controllers based on the target gait for operating the legged robot, each gait controller associated with a respective gait for operating the legged robot and comprising:
• a validity check associated with the respective gait;
• and
• one or more output parameters associated with the respective gait;
• determining whether the instantaneous state of the legged robot satisfies the validity check associated with the respective gait for a first gait controller of the ordered list of gait controllers, the respective gait for the first gait controller comprising the target gait;
• and
• when the instantaneous state of the legged robot does not satisfy the validity check associated with the target gait for the first gait controller:
• determining whether the instantaneous state of the legged robot satisfies the validity check associated with the respective gait for a second gait controller of the ordered list of gait controllers, the respective gait for the second gait controller comprising a first intermediary gait for operating the legged robot to achieve the target gait;
• and
• when the instantaneous state of the legged robot satisfies the validity check associated with the first intermediary gait for the second gait controller, instructing, by the processor, the leg members and/or the leg joints to actuate based on the one or more output parameters associated with the first intermediary gait for the second gait controller, the actuation of the leg members and/or the leg joints causing the legged robot to achieve the first intermediary gait.

A method comprising:

• receiving, at a processor of a legged robot, sensor information from one or more sensors of the legged robot, the legged robot comprising leg members and leg joints;
• determining, by the processor, an instantaneous state of the legged robot based on the sensor information;
• determining, by the processor, a target gait for operating the legged robot on a ground surface;
• obtaining, by the processor, a list of gait controllers based on the target gait for operating the legged robot, each gait controller of the list of gait controllers associated with a respective intermediary gait for operating the legged robot to achieve the target gait and comprising one or more output parameters associated with the respective intermediary gait;
• assigning, by the processor, a cost to each gait controller of the list of gait controllers based on the instantaneous state of the robot;
• sorting, by the processor, the list of gait controllers in increasing order of cost;
• and
• instructing, by the processor, the leg members and/or the leg joints to actuate based on the one or more output parameters associated with the respective intermediary gait for the gait controller of the sorted list of gait controllers having the lowest cost, the actuation of the leg members and/or the leg joints causing the legged robot to achieve the respective intermediary gait.

A legged robot comprising:

• leg members connected by leg joints;
• one or more sensors;
• a processor in communication with the one or more sensors;
• and
• a non-transitory computer-readable medium in communication with the processor and storing instructions, that when executed by the processor, cause the processor to perform operations comprising:
• receiving sensor information from the one or more sensors of the legged robot;
• determining an instantaneous state of the legged robot based on the sensor information;
• determining a target gait for operating the legged robot on a ground surface;
• obtaining a list of gait controllers based on the target gait for operating the legged robot, each gait controller of the list of gait controllers associated with a respective intermediary gait for operating the legged robot to achieve the target gait and comprising one or more output parameters associated with the respective intermediary gait;
• assigning a cost to each gait controller of the list of gait controllers based on the instantaneous state of the robot;
• sorting the list of gait controllers in increasing order of cost;
• and
• instructing the leg members and/or the leg joints to actuate based on the one or more output parameters associated with the respective intermediary gait for the gait controller of the sorted list of gait controllers having the lowest cost, the actuation of the leg members and/or the leg joints causing the legged robot to achieve the respective intermediary gait.