Patent ID: 8079432

Claim:
A robot capable of addressing various obstacles, the robot comprising: a chassis defining a central open volume and having a chassis center of gravity; a steerable drive supporting the chassis; a set of driven flippers, each flipper having a proximal end, a distal end, and a flipper center of gravity therebetween, each the proximal end of each flipper coupled to the chassis near the leading end of the chassis; a neck having a pivot end, a distal end, and a neck center of gravity therebetween, the neck pivotable about a second pivot axis substantially at the leading end of the chassis, having at least two tilt axis actuators along a length thereof; and a sensor head at the distal end of the neck, the head having a pivot end, a distal end, and a head center of gravity therebetween, the head pivotable with respect to the neck about a third pivot axis at the distal end of the neck; the neck and sensor head being movable between different configurations including: (i) a stable stair ascending position in which the centers of gravity of the head, neck, and flippers are positioned to shift a vertical projection of the overall center of gravity of the robot to at least one step span in front of the rearmost main track ground contact point and at least one step span behind the foremost flipper track ground contact point; and (ii) an unstable stair ascending position in which the centers of gravity of the head, neck, and flippers are positioned to shift a vertical projection of the overall center of gravity of the robot to outside the stable range.