Abstract
This paper deals with locomotion control of a snake like articulated robot consisting of serially conected links with active joints. Some animal snakes raise their part of the body during locomotion - known as sinus-lifting. A goal of this paper is to give one explanation for such motion in view of control analysis. We have ever introduced a notion dynamic a manipulability with consideration of constraint force against side slip. The maximum constraint force depends on environmental condition and normal force on each link. We show the optimal mass distribution in terms of the proposed manipulability is associated with sinus-lifting.