Whole-Body Nonlinear Model Predictive Control Through Contacts for Quadrupeds
This enables more dynamic and robust locomotion for quadrupeds, addressing a domain-specific challenge in robotics.
The paper tackles the problem of whole-body control for quadrupeds using a Nonlinear Model Predictive Control approach with explicit contact dynamics, achieving real-time solver rates up to 190 Hz, which outperforms state-of-the-art methods by at least an order of magnitude.
In this work we present a whole-body Nonlinear Model Predictive Control approach for Rigid Body Systems subject to contacts. We use a full dynamic system model which also includes explicit contact dynamics. Therefore, contact locations, sequences and timings are not prespecified but optimized by the solver. Yet, thorough numerical and software engineering allows for running the nonlinear Optimal Control solver at rates up to 190 Hz on a quadruped for a time horizon of half a second. This outperforms the state of the art by at least one order of magnitude. Hardware experiments in form of periodic and non-periodic tasks are applied to two quadrupeds with different actuation systems. The obtained results underline the performance, transferability and robustness of the approach.