Dennis Ossadnik — accepted AI-conference papers

2025

Braking Control in Clutched-Elastic Robots: Coordinating the Underactuation-to-Actuation Transition

Vasilije Rakcevic, Dennis Ossadnik, Edmundo Pozo Fortunic, Mehmet Can Yildirim, Valentin Le Mesle, Sami Haddadin

IROS 2025

Robots with intrinsic joint elasticity can perform highly dynamic manoeuvres by leveraging energy storage and release, enabling explosive motions such as throwing. By augmenting elastic robots with clutch mechanisms, link decoupling can be used to fully exploit inertial coupling effects and gravitat

Cited by 0 Source ↗Scholar ↗

2024

Optimal Control for Clutched-Elastic Robots: A Contact-Implicit Approach

Dennis Ossadnik, Vasilije Rakčević, Mehmet C. Yildirim, Edmundo Pozo Fortunić, Hugo T. M. Kussaba, Abdalla Swikir +1

ICRA 2024poster

Intrinsically elastic robots surpass their rigid counterparts in a range of different characteristics. By temporarily storing potential energy and subsequently converting it to kinetic energy, elastic robots are capable of highly dynamic motions even with limited motor power. However, the time-depen…

Cited by 1 Source ↗Scholar ↗

2023

Optimally Controlling the Timing of Energy Transfer in Elastic Joints: Experimental Validation of the Bi-Stiffness Actuation Concept

Edmundo Pozo Fortunic, Mehmet Can Yildirim, Dennis Ossadnik, Abdalla Swikir, Saeed Abdolshah, Sami Haddadin

RA-L 2023

Elastic actuation taps into elastic elements' energy storage for dynamic motions beyond rigid actuation. While Series Elastic Actuators (SEA) and Variable Stiffness Actuators (VSA) are highly sophisticated, they do not fully provide control over energy transfer timing. To overcome this problem on th

Cited by 4 Source ↗Scholar ↗

2022

BSA - Bi-Stiffness Actuation for optimally exploiting intrinsic compliance and inertial coupling effects in elastic joint robots

Dennis Ossadnik, Mehmet C. Yildirim, Fan Wu, Abdalla Swikir, Hugo T. M. Kussaba, Saeed Abdolshah +1

IROS 2022poster

Compliance in actuation has been exploited to generate highly dynamic maneuvers such as throwing that take advantage of the potential energy stored in joint springs. However, the energy storage and release could not be well-timed yet. On the contrary, for multi-link systems, the natural system dynam…

Cited by 4 Source ↗Scholar ↗

2021

Nonlinear stiffness allows passive dynamic hopping for one-legged robots with an upright trunk

Dennis Ossadnik, Elisabeth Jensen, Sami Haddadin

ICRA 2021poster

Template models are frequently used to simplify the control dynamics for robot hopping or running. Passive limit cycles can emerge for such systems and be exploited for energy-efficient control. A grand challenge in locomotion is trunk stabilization when the hip is offset from the center of mass (Co…

Cited by 4 Source ↗Scholar ↗

2021

ULT-model: Towards a one-legged unified locomotion template model for forward hopping with an upright trunk

Dennis Ossadnik, Elisabeth Jensen, Sami Haddadin

ICRA 2021poster

While many advancements have been made in the development of template models for describing upright-trunk locomotion, the majority of the effort has been focused on the stance phase. In this paper, we develop a new compact dynamic model as a first step toward a fully unified locomotion template mode…

Cited by 2 Source ↗Scholar ↗