A Navigation System for Goal Acquisition in Unknown Environments
The cross-country navigation system described in the previous chapter assumes that intermediate goal points have been defined between the starting position and the final goal position. Placement of goal points assumes implicitly that some knowledge of the environment, for example in the form of a map, was available prior to the mission. This knowledge may not have been available, may have been incomplete, and may have been erroneous. In such cases, the system must be able to map its environment on the fly and re-compute its path as new information is added to its map. This chapter describes how, by combining the SMARTY system for obstacle detection and avoidance described in Chapter 6 with the D* planning system described in Chapter 11, we are able to conduct long-range autonomous missions with dynamic map building and path planning.