Exploiting visual constraints in the synthesis of uncertainty-tolerant motion plans

The direciional backprojection i s one of the primary tools used b y fine-motion planning systems. Informally, a directional backprojection i s the set of configurations f rom which a commanded motion i s guaranteed to reach a goal configuration. It has been shown that, for force controlled motions, the topology of the directional backprojection only changes at a finite set of critical velocity orientations. In a related paper, we have shown how visual constraints can be exploited in the construction of directional backprojections. Here, we show how the introduction of visual constraints into the backprojection formali sm aflects the computation and structure of the nondirectional backprojection. Specifically, by examining the behavior of visual constraints as a function of the direction of the commanded velocity, we are able to determine the new criteria for critical velocity orientataons (i.e. velocity orientations at which the topology of the directional backprojection, including visual constraint rays, might change).