Perceptive Locomotion in Rough Terrain - Online Foothold Optimization

• Published in: IEEE robotics and automation letters Vol. 5; no. 4; pp. 5370 - 5376
• Main Authors: Jenelten, Fabian, Miki, Takahiro, Vijayan, Aravind E, Bjelonic, Marko, Hutter, Marco
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.10.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Elevation; End effectors; Foot; foothold optimization; Legged locomotion; Legged robots; Locomotion; motion control; Optimization; optimization and optimal control; perceptive locomotion; Pipelines; Robot dynamics; Robot sensing systems; Rough terrain; Schedules
• ISSN: 2377-3766; 2377-3766
• DOI: 10.1109/LRA.2020.3007427

Compared to wheeled vehicles, legged systems have a vast potential to traverse challenging terrain. To exploit the full potential, it is crucial to tightly integrate terrain perception for foothold planning. We present a hierarchical locomotion planner together with a foothold optimizer that finds locally optimal footholds within an elevation map. The map is generated in real-time from on-board depth sensors. We further propose a terrain-aware contact schedule to deal with actuator velocity limits. We validate the combined locomotion pipeline on our quadrupedal robot ANYmal with a variety of simulated and real-world experiments. We show that our method can cope with stairs and obstacles of heights up to 33% of the robot's leg length.