We introduce the notion of expansiveness to characterize a family of robot
configuration spaces whose connectivity can be effectively captured by a ro
admap of randomly-sampled milestones. The analysis of expansive configurati
on spaces has inspired us to develop a new randomized planning algorithm. T
his new algorithm tries to sample only the portion of the configuration spa
ce that is relevant to the current query, avoiding the cost of precomputing
a roadmap for the entire configuration space. Thus, it is well-suited for
problems where only a single query is submitted for a given environment. Th
e algorithm has been implemented and successfully applied to complex assemb
ly maintainability problems from the automotive industry.