A set of architectural concepts that address the needs for integrating high-level planning activities with lower-level reactive or participatory behaviors is presented. Based on lessons learned from the authors' experience with a hierarchical architecture for autonomous cross-country navigation, various pitfalls that may arise from the misuse of abstraction have been recognized. Consequently, a new approach that emphasizes the minimization of information loss both within and between system layers has been adopted. This change in perspective has allowed the authors to greatly enhance the overall capabilities and performance of their system.>

A description is given of the first cross-country map and sensor-based autonomous operation of a robotic vehicle. Experiments on the autonomous land vehicle (ALV) in natural terrain were performed. An overview of the software architecture is provided, and details of the perception and planning techniques are presented. Two key experiments in which the vehicle avoided known and unknown obstacles in its path are described.>

A review of early work on a project to develop autonomous vehicle control technology is presented. The primary goal of this effort is the development of a generic capability that can be specialized to a wide range of DoD applications. The emphasis in this project is development of the fundamental Al-based technology required by autonomous systems and the implementation of a testbed environment to evaluate and demonstrate the system capabilities.

This study describes the theoretical and practical aspects of the design and computer simulation of a heuristic based navigation algorithm. An algorithm is developed which provides a convenient testing system for generalized navigation strategies on a fixed map which may be known or unknown to a system. A variety of maps are simulated and the navigation results are compared.