FastStair: Learning to Run up Stairs With Humanoid Robots. - Yan Liu 112; Tao Yu 012; Haolin Song; Hongbo Zhu; Nianzong Hu; Yuzhi Hao; Xiuyong Yao; Xizhe Zang; Hua Chen 007; Jie Zhao 003 (IEEE Robotics Autom. Lett., 2026)