Multiobjective Control with Frictional Contacts
Standing is a fundamental skill mastered by humans and animals alike. Although easy for adults, it requires careful and deliberate manipulation of contact forces. The variation in contact confguration (e.g., standing on one foot, on uneven ground, or while holding on for support) presents a diffcult challenge for interactive simulation of humans and animals, especially while performing tasks in the presence of external disturbances. We describe an analytic approach for control of standing in three-dimensional simulations based upon local optimization. At any point in time, the control system solves a quadratic program to compute actuation by maximizing the performance of multiple motion objectives subject to constraints imposed by actuation limits and contact configuration.
Interactive Animation of Dynamic Manipulation
Lifelike animation of object manipulation requires dynamic interaction between animated characters, objects, and their environment. These interactions can be animated automatically with physically based simulations but proper controls are needed to animate characters that move realistically and that accomplish tasks in spite of unexpected disturbances. This paper describes an effcient control algorithm that generates realistic animations by incorporating motion data into task execution. The end result is a versatile system for interactive animation of dynamic manipulation tasks such as lifting, catching, and throwing.