The standard circular gait of a quadruped walking vehicle

A quadruped walking vehicle has the potential capability of being developed into a vehicle of high mobility and adaptability to terrain by making use of its high degree of motion freedom. The authors have investigated the gait control problems of a walking vehicle, i.e. the straightforward or crab walk of the vehicle on rough terrains. This paper introduces a more generalized gait, namely, a circular gait around an arbitrarily located turn center, and discusses a standard circular gait. The standard circular gait is the one which maximizes the speed of walking and the rotational angle in a circular walk, and this consideration forms the basis of the discussion on advanced gait control problems. This paper formalizes the problems and analyses them by using mathematical optimization methods such as non-linear programming. Computations are carried out on a TITAN III, the quadruped walking vehicle model constructed by the authors. Several characteristics of the optimum gait and the final gait selection chart are derived. The validity of these conditions was verified by a circular walking experiment using the TITAN III.