Uploaded April 2024 | Updated September 2026, 3 hours ago
Microsoft Future Leaders in Robotics and AI Seminar Series: Stepping into the Future: Unveiling a Novel Stair Climbing Controller
Online Seminar
Oluwami (Wami) Dosunmu-Ogunbi
PhD Candidate
University of Michigan
Toward the goal of developing robots for a robot-assisted world, these robots need to be equipped with intelligent controllers that allow for robust navigation in our human-centric world. Stairs pose a unique challenge for humans and bipedal robots alike. A new control paradigm using angular momentum and foot placement as state variables in the linear inverted pendulum model has expanded the realm of possibilities for the control of bipedal robots. This new paradigm, known as the Angular Linear Inverted Pendulum (ALIP) model, has shown effectiveness in cases where a robot's center of mass height can be assumed to be constant or near constant as well as in cases where there are no non-kinematic restrictions on foot placement. Walking up and down stairs violates both of these assumptions, where center of mass height varies significantly within a step and the geometry of the stairs restrict the effectiveness of foot placement.
In this presentation, we explore a variation of the ALIP model that allows the length of the virtual pendulum formed by the robot's stance foot and center of mass to follow smooth trajectories during a step. We couple this model with a control strategy constructed from a novel combination of virtual constraint-based control and a model predictive control algorithm to stabilize a stair-climbing gait that does not solely rely on foot placement. Simulations on a 20-degree of freedom model of the Cassie biped in the SimMechanics simulation environment show that the controller is able to achieve periodic gait. Hardware experiments also show the promise of improving the robustness of walking gaits on inclined surfaces.
For more information on the Maryland Robotics Center see:
https://robotics.umd.edu
Microsoft Future Leaders in Robotics and AI Seminar Series: Stepping into the Future: Unveiling a Novel Stair Climbing Controller
Online Seminar
Oluwami (Wami) Dosunmu-Ogunbi
PhD Candidate
University of Michigan
Toward the goal of developing robots for a robot-assisted world, these robots need to be equipped with intelligent controllers that allow for robust navigation in our human-centric world. Stairs pose a unique challenge for humans and bipedal robots alike. A new control paradigm using angular momentum and foot placement as state variables in the linear inverted pendulum model has expanded the realm of possibilities for the control of bipedal robots. This new paradigm, known as the Angular Linear Inverted Pendulum (ALIP) model, has shown effectiveness in cases where a robot's center of mass height can be assumed to be constant or near constant as well as in cases where there are no non-kinematic restrictions on foot placement. Walking up and down stairs violates both of these assumptions, where center of mass height varies significantly within a step and the geometry of the stairs restrict the effectiveness of foot placement.
In this presentation, we explore a variation of the ALIP model that allows the length of the virtual pendulum formed by the robot's stance foot and center of mass to follow smooth trajectories during a step. We couple this model with a control strategy constructed from a novel combination of virtual constraint-based control and a model predictive control algorithm to stabilize a stair-climbing gait that does not solely rely on foot placement. Simulations on a 20-degree of freedom model of the Cassie biped in the SimMechanics simulation environment show that the controller is able to achieve periodic gait. Hardware experiments also show the promise of improving the robustness of walking gaits on inclined surfaces.
For more information on the Maryland Robotics Center see:
https://robotics.umd.edu
