PolygMap: A Perceptive Locomotion Framework for Humanoid Robot Stair Climbing
Bingquan Li, Ning Wang, Tianwei Zhang, Zhicheng He, Yucong Wu
TL;DR
The paper addresses the challenge of humanoid stair climbing by introducing a perception-based locomotion framework that fuses LiDAR and RGB-D data to construct a polygonal staircase plane semantic map, from which footholds are generated and integrated into real-time footstep planning. It combines multi-sensor fusion–based state estimation, plane-based foothold extraction via RANSAC, and a gait planner that generates smooth torso-foot trajectories at 20-30 Hz on an onboard NVIDIA Orin. Major contributions include the polygonal stair map construction, erosion-based foothold extraction, and a real-time foothold-aware trajectory planner, validated through Gazebo simulations and real-world indoor/outdoor stair climbs. The framework demonstrates robust stair climbing under perception noise and varying conditions, enabling reliable operation on long staircases with minimal footstep errors. Open-source release is planned to facilitate adoption and further research in perception-guided humanoid locomotion.
Abstract
Recently, biped robot walking technology has been significantly developed, mainly in the context of a bland walking scheme. To emulate human walking, robots need to step on the positions they see in unknown spaces accurately. In this paper, we present PolyMap, a perception-based locomotion planning framework for humanoid robots to climb stairs. Our core idea is to build a real-time polygonal staircase plane semantic map, followed by a footstep planar using these polygonal plane segments. These plane segmentation and visual odometry are done by multi-sensor fusion(LiDAR, RGB-D camera and IMUs). The proposed framework is deployed on a NVIDIA Orin, which performs 20-30 Hz whole-body motion planning output. Both indoor and outdoor real-scene experiments indicate that our method is efficient and robust for humanoid robot stair climbing.
