OPTIMAL-CONTROL OF AN N-LEGGED ROBOT

This paper presents a method for controlling the dynamic balance of le gged robots using optimal state feedback. Rather than being restricted to a specific number of legs, the method considers the general case o f a machine with n legs. The analysis starts with a non-linear dynamic model of a general robot and a set off equations representing the con straints on motion imposed by those feet in contact with the ground. T hese equations are used to derive a state-space model of order proport ional to the number of degrees of freedom of the system, which will va ry with the current constraint conditions. An optimal feedback gain ma trix is then calculated for the linear model using standard techniques . The choice of operating point and optimization parameters is discuss ed. The effectiveness of the method is illustrated through simulation responses obtained for a biped model under both single and double supp ort constraint conditions.