Articulated Body Dynamics Simulation using Optimization Integrator

We present a novel optimization-based algorithm for articulated body dynamics simulation. We formulate the governing equations of rigid body dynamics using only the position variables and recast the position-based articulated dynamics as an optimization problem. We also extend our framework to handle joint limits, control forces/torques, fluid drag forces, and frictional contact forces. Our reformulation allows us to use an off-the-shelf optimization algorithm to time integrate the articulated body with an arbitrarily large timestep size and analyze the stability. Our algorithm can efficiently perform each iteration of optimization within O(N) time using Quasi-Newton method and O(N) time using Newton’s method, where N is the number of links. We highlight the performance on different benchmarks and compare the performance with prior articulated body dynamics simulators.