Bipedal walking gait with variable stiffness knees

The Segmented Spring-Loaded Inverted Pendulum model is analysed, and it is shown that it exhibits walking gait. We propose a control architecture that exploits control of the knee stiffness to provide robustness of the system with respect to changes in gait. This controller is extended for a realistic bipedal robot model that uses variable stiffness actuators to control the knee stiffness. The variable knee stiffness is then used to stabilise the system into a walking gait and to inject energy losses generated by friction and foot impacts.