To enhance the well known, self-stabilizing effects of Spring Loaded Inverted Pendulum (SLIP) models, researchers have proposed a variety of dead-beat controllers that adjust model parameters (angel of attack, spring stiffness), such that a disturbance is rejected within a single step. While such laws can be nicely encoded for disturbances in hopping height (by using the time of flight as a measure of vertical position), they suffer from substantial drift due to the missing information about the forward velocity and inaccuracies in the actual system model. Without requiring additional complex sensors, we propose a method to estimate the forward velocity of a SLIP model based solely on measuring the time of stance. This method is additionally able to perform realtime parameter estimation, which paves the road to implement a full state dead-beat controller that can reject arbitrary disturbances even in the presence of model and sensor errors.

This paper investigates the mechanical benefits of employing a passive foot segment to improve energetic efficiency in legged running. The proposed lightweight design significantly reduces impact and damping losses, while simultaneously allowing for a natural-looking stance configuration. Actuator input and ankle spring properties were optimized in simulation and successfully tested in 2D running experiments.

This paper introduces ParcelBot, a tracked robot designed as an assistance device for packet delivery services. Its application field requires high mobility in an artificial environment, including the ability to overcome fairly large obstacles such as s or stairs. The platform is moving on tracks but consists of a mechanism to tilt the robot, so that it behaves like a wheeled system. Compared to pure tracked or wheeled robots, the combination leads to an increased obstacle climbing ability, superior maneuverability and higher energy efficiency due to less friction losses when navigating on flat ground. The paper focuses on the mechanical design of the prototype and highlights a selected number of experiments.