Robust Stabilization of Periodic Gaits for Quadrupedal Locomotion via QP-Based Virtual Constraint Controllers

This letter develops, theoretically justifies, and experimentally implements an optimization-based nonlinear control methodology for stabilizing quadrupedal locomotion. framework utilizes virtual constraints Lyapunov functions (CLFs) in the context of quadratic programs (QPs) to robustly stabilize periodic orbits hybrid models robots. Properties proposed QP are studied wherein sufficient conditions continuous differentiability controller presented. Additionally, this addresses robust stabilization problem based on Poincaré sections analysis input-to-state stability (ISS). The is numerically validated A1 robot with 18 degrees freedom demonstrate trotting gaits against external disturbances unknown payloads.