Abstract
A leg-wheel robot has mechanically separated legs and wheels, and it performs high mobitity and stability on the rough terrain. In the first part of this paper, we propose a gait algorithm which enables the robot to preserve continuous locomotion under the random velocity command such as the human operator inputs. The gait algorithm, which uses predictive control, determines the timing of the legs' lifting to avoid the legs reaching the border of the work space. The predictive control is based on the comparison between the time necessary to return the support legs and the time left before they reach the border of the work space. In the second part, a velocity limitation method for the gait algorithm is discussed. This method limits the velocity command when it exceeds the mechanical perfor-mance of the robot. Combined use of the velocity limitation method with the gait algorithm ensures the continuity of locomotion, and makes the efficient gait pattern with a long step length and low frequency of leg phase change. The proposed algorithms are evaluated by simulation.
