Despite beingmotivated by problems in robotics and control theory, the present paper does not discuss the effect of general forces. The control theorywe have used as motivation deals largely with “internal forces” such as those that naturally enter into the snakeboard. While we do not systematically deal with general external forces in this paper, we do have them in mind and plan to include them in future LAM [1994] and JALNAPURKAR [1995] have pointed out, external forces acting on the system have to be treated carefully in the context of the Lagrange-d’Alembert principle. Our framework is that of the traditional setup for constraint forces as described in.
