Event-based walking control - From neurobiology to biped robots

In this paper we describe an event-based walking control system for biped robots. Classically, the control of biped robots has been separated into walking pattern generation and stabilizing control. While this is an effective strategy in well-known environments, walking in rough, unmodelled terrain can easily destabilize the system. Findings from neurobiology suggest that gait generation in animals and humans is strongly linked to sensory signals indicating certain events in the gait cycle. We therefore propose an event-based controller that triggers phase transitions based on the sensed walking state instead of only relying on time-based reference trajectories. We have implemented the proposed approach on our humanoid robot Lola. We present simulations and experimental results demonstrating the effectiveness of the approach when walking over unknown obstacles.