Event Location: GHC 4405

Abstract: Personal mobile robots will soon be operating and closely interacting with us in human environments. They will offer a variety of assistive technologies that will augment our capabilities and enhance our lives. Dynamically stable mobile robots that actively balance can be effective personal mobile robots as they can be tall enough for eye-level interaction and narrow enough to navigate cluttered environments. They are capable of safe, gentle physical interaction and have the dynamic capabilities to move with speed and grace comparable to that of humans. This proposed thesis addresses the problem of achieving fast, dynamic and graceful navigation of balancing mobile robots using an integrated planning and control procedure that exploits the natural dynamics of the system.

The proposed approach has two major components: planning in shape space and hybrid control architecture for graceful motion planning. Motions are planned in shape space that enable the balancing robots to achieve fast, graceful motions in position space, taking into account the dynamic constraint equations. Controllers called motion policies are designed to achieve fast, graceful motions in small domains of the position space that are collision-free. A hybrid control architecture is used for motion planning, where the planner chooses a sequence of gracefully composable motion policies to achieve the overall navigation task. This ensures that the high-level motion planner has knowledge of the low-level controller it uses. Each motion policy is designed such that when sequentially composed they result in overall graceful motion. This ensures that the low-level controllers understand what the high-level motion planner is trying to achieve thereby forming a truly integrated planning and control procedure. Experimental validation of the proposed work is done on the ballbot, a dynamically stable mobile robot that balances on a ball.

Committee:Ralph Hollis, Chair

George Kantor

Howie Choset

Russ Tedrake, MIT