Patent ID: 8763732

Claim:
A method of negotiating an obstacle, the method comprising: driving an articulated vehicle along a drive direction over a surface, the vehicle comprising: a rigid main frame having forward and rearward portions and right and left sides; a drive system supporting the rigid main frame with the frame spaced from the surface, the drive system configured to propel the articulated vehicle over the surface; right and left arms, each arm having a proximal end and a distal end, the proximal end of each arm being pivotally coupled to the forward portion of the rigid main frame about a transverse axis generally perpendicular to the sides of the rigid main frame and the distal end being pivotable 360° about the transverse axis without interference from other parts of the articulated vehicle; and an articulator motor disposed on the rigid main frame and coupled to each arm for pivoting each arm about the transverse axis; driving, while the rigid main frame remains rigid, the articulated vehicle to approach an obstacle with the forward portion of the articulated vehicle; pivoting, while the rigid main frame remains rigid, the arms about the transverse axis from a stowed position next to the main frame downward and away from the main frame, thereby supporting the rigid main frame on a length of at least one of the arms extending from the proximal end to the distal end thereof and lifting the rearward portion of the main frame above the support surface and above the transverse axis; pivoting, while the rigid main frame remains rigid, the arms to drive the main frame past a vertical position, causing the articulated vehicle to fall over substantially against the object and thereby invert the main frame; and driving, while the rigid main frame remains rigid, onto the obstacle.