Alexander Ewald

Technische Universität München | TUM · Institute of Applied Mechanics

Walking is the most common terrestrial form of locomotion in animals. Its great versatility and flexibility has led to many attempts at building walking machines with similar capabilities. The control of walking is an active research area both in neurobiology and robotics, with a large and growing body of work. This paper gives an overview of the c...

Pushing, soft ground contact and other unknown large disturbances can cause humanoid robots to fall. In order to face such problems, an accurate and fast model of the robot is necessary to estimate the state at a certain time in the future using only current measurements. We approximate the robot by a three-mass model with two degrees of freedom. U...

The ability to avoid collisions is crucial for locomotion in cluttered environments. It is not enough to plan collision-free movements in advance when the environment is dynamic and not precisely known. We developed a new method which generates locally optimized trajectories online during the feedback control in order to dynamically avoid obstacles...

Robust walking motion of humanoid robots requires a sensor system that can accurately sense the robot's state and its environment. Especially in case the ground is not modeled and uneven, information about the contact state is crucial to initiate an appropriate response. Many humanoid robots use strain gauge-based force/torque sensors to obtain inf...

Zusammenfassung Der Beitrag gibt einen Überblick der Forschung an voll aktuierten, humanoiden Laufmaschinen. Neben einer allgemeinen Einführung wird ein kurzer Abriss der Geschichte humanoider Roboter gegeben. Die bekanntesten Systeme werden nach Forschungszentren gegliedert vorgestellt. Aufbauend auf einer kurzen Einführung zu grundlegenden Aspekt...

This paper gives an overview of the dynamics and control of the humanoid walking robot Lola. A brief analysis of the robot’s multibody dynamics motivates our approach to biped walking control. After a brief description of the robot Lola we outline the architecture of its hierarchical walking control system. We also present the real-time planning me...

This paper describes the control, communication and sensor network of the humanoid robot LOLA. A brief description of the complex decentralized electronic architecture will be given. A dedicated circuit board has been developed as decentralized computation device and sensor-controller interface. A detailed description of the hardware and software c...

Zusammenfassung Dieser Beitrag beschreibt ein System zur Regelung redundanter zweibeiniger Roboter. Das hierarchisch angelegte System erzeugt aus groben Vorgaben zum gewünschten Gang in Echtzeit eine stabile Laufbewegung. Die stabilisierende Regelung kompensiert Modellfehler, externe Kräfte und Bodenunebenheiten. Durch Nutzung kinematischer Redunda...

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 n...

In the field of humanoid robotics, developing a walking system capable of adapting to new situations is driven by the prospect of employing humanoid robots in unknown environments. By evaluating sensor data, the control system may acquire information about the environment and utilize that information for adaptation. In this paper, we focus on the r...