Rising Motion Controllers for Physically Simulated Characters

The control of physics-based simulated characters is an important open problem with potential applications in film, games, robotics, and biomechanics. While many methods have been developed for locomotion and quiescent stance, the problem of returning to a standing posture from a sitting or fallen posture has received much less attention. In this thesis, we develop controllers for biped sit-to-stand, quadruped getting-up, and biped prone-to-stand motions. These controllers are created from a shared set of simple components including pose tracking, root orientation correction, and virtual force based control. We also develop an optimization strategy that generates fast, dynamic rising motions from an initial statically stable motion. This strategy is also used to generalize controllers to sloped terrain and characters of varying size.