The goal of this program is to develop a fundamental understanding of the problem-solving activity underlying climbing, then to create new technologies based on this understanding that will enable non-specific multi-limbed robots to free-climb natural, unstructured, vertical terrain. Climbing is regarded by human climbers to be a physical problem-solving activity in a highly unstructured environment. Overall, climbing involves a tight combination of fast but insightful reasoning, goal-directed sensing, and reactive execution. Sophisticated planning is required to handle hard constraints (e.g., equilibrium, torque limits, collision) on the agent's motion, as well as softer ones (e.g., uncertainties, risk level, energy consumption). Precise sensing (e.g., tactile, vision) is used to search and detect potential holds in the unstructured rock face, estimate the location and characteristics of contact points, and anticipate or detect slip. Fine control is needed to maintain balance through careful distribution of contact forces. A solution to the climbing problem requires that these activities be fused into a seamless process. This program will seek advances in the specific areas of terrain modeling, multi-constraint trajectory planning and robust motion strategies with an initial emphasis on multi-constraint trajectory planning and control. The LEMUR II robot of JPL will be used to validate experimentally the results of the program. It will be used to demonstrate multi-step climbing in an unknown environment. The goal is to have it climb autonomously an indoor rock wall (similar to a climbing gym).
