AUTHOR=Mingo Hoffman Enrico , Zhou Chengxu , Parigi Polverini Matteo TITLE=Editorial: Advancements in trajectory optimization and model predictive control for legged systems JOURNAL=Frontiers in Robotics and AI VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/robotics-and-ai/articles/10.3389/frobt.2022.1002552 DOI=10.3389/frobt.2022.1002552 ISSN=2296-9144