A document presents further information on the subject matter of “Controlling Herds of Cooperative Robots” (NPO-40723), NASA Tech Briefs, Vol. 30, No. 4 (April 2006), page 81. To recapitulate: A methodology for controlling a herd of cooperative and autonomous mobile robots exploring the surface of a remote planet or moon (specifically, Titan or Titan-like) is undergoing development. The proposed configuration of mobile robots consists of a blimp and a herd of surface sondes. The blimp is the leader of the herd, and it commands the other robots to move to locations on the surface or below the surface to conduct science operations. Once a target is chosen, the sondes cooperatively aim sensors at the target to maximize scientific return. This hierarchical and cooperative behavior is necessary in the face of such unpredictable factors as terrain obstacles and uncertainties in the model of the environment.

This document describes the cooperation architecture and the estimation algorithm. Dynamical and kinematical models of the blimp and surface sondes are derived, and a robust guidance and control algorithm, based on a potential-field mathematical model, is developed. This guidance-and-control algorithm can compute actuator forces needed for moving the surface sondes across the terrain while avoiding hazards and collisions with each other and at the same time remaining within communication range with the blimp.

The document describes the results of the computational simulations of a one-blimp, three-surface-sonde herd in various operational scenarios, including sensitivity studies as a function of distributed communication and processing delays between the sondes and the blimp. From results of the simulations, it is concluded that the methodology is feasible, even if there are significant uncertainties in the dynamical models.

This work was done by Marco Quadrelli and Johnny Chang of Caltech for NASA’s Jet Propulsion Laboratory. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Mechanics/Machinery category.

The software used in this innovation is available for commercial licensing. Please contact Karina Edmonds of the California Institute of Technology at (626) 395-2322. Refer to NPO-35031.