Dynamic Simulation and Control of Articulated Limbs

Citation

Mitchell, Marcus Quintana (2009) Dynamic Simulation and Control of Articulated Limbs. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/2FAM-6A26. https://resolver.caltech.edu/CaltechETD:etd-02162009-054828

Abstract

Many useful mechanisms can be modelled as articulated systems: collections of rigid bodies linked together with joints that constrain relative movement. The two parts of this thesis study the complementary problems of simulation and control for such systems. In the first part, we describe an implementation and extension of a physically based modelling framework known as "dynamic constraints" in which forces of constraint linking bodies in an articulated system are explicitly calculated. In addition to identifying some important robustness and stability issues for these calculations, we extend the framework to systems whose internal degrees of freedom can be directly parameterized. This permits significant efficiency gains for mechanisms which model limbs. The second part of the thesis centers on the adaptive control of limb configuration through simulated actuators. In this problem, the nonlinear structure and parametric details of a limb are assumed to be unknown. We present and illustrate the performance of an adaptive scheme which performs considerably better than conventional nonadaptive techniques, and which is competitive with adaptive methods which use more a priori knowledge of limb dynamics.

Thesis Files