14 accepted papers
Learning from demonstration (LfD) offers an intuitive alternative to manual coding by leveraging natural human behavior, while Human-Robot Interaction (HRI) provides an intuitive means to refine and adapt learned skills. Among interaction modalities, physical contact is a natural and effective way t
Shared control enables users with motor impairments to control high-dimensional assistive robots with low-dimensional user interfaces. The challenge is to simultaneously 1) provide support for completing daily living tasks 2) enable sufficient freedom of movement to foster user empowerment 3) ensure
In this paper, we propose a model predictive control (MPC) that accomplishes interactive robotic tasks, in which multiple contacts may occur at unknown locations. To address such scenarios, we made an explicit contact feedback loop in the MPC framework. An algorithm called Multi-Contact Particle Fil…
Since modern robots are supposed to work closely together with humans, physical human-robot interaction is gaining importance. One crucial aspect for safe collaboration is a robust collision reaction strategy that is triggered after an unintentional physical contact. In this work, we propose a dynam…
Controlling the contact force on various surfaces is essential in many robotic applications such as in service tasks or industrial use cases. Mostly, classical impedance and hybrid motion-force control approaches are employed for these kinds of physical interaction scenarios. In this work, an extend
Modern Lightweight robots are constructed to be collaborative, which often results in a low structural stiffness compared to conventional rigid robots. Therefore, the controller must be able to handle the dynamic oscillatory effect mainly due to the intrinsic joint elasticity. Singular perturbation
Physical human-robot interaction is known to be a crucial aspect in modern lightweight robotics. Herein, the estimation of external interactions is essential for the effective and safe collaboration. In this work, an extended momentum-based disturbance observer is presented which includes the sensin…
Injuries, accidents, strokes, and other diseases can significantly degrade the capabilities to perform even the most simple activities in daily life. A large share of these cases involves neuromuscular diseases, which lead to severely reduced muscle function. However, even though affected people are…
Lightweight robots are known to be intrinsically elastic in their joints. The established classical approaches to control such systems are mostly based on motor-side coordinates since the joints are comparatively stiff. However, that inevitably introduces errors in the coordinates that actually matt…
Light-weight robotic manipulators can be used to restore the manipulation capability of people with a motor disability. However, manipulating the environment poses a complex task, especially when the control interface is of low bandwidth, as may be the case for users with impairments. Therefore, we…
A physically-motivated friction model with a parametric description of the nonlinear dependency of the temperature and velocity as well as the dependency on external load is presented. The fully parametric approach extends a static friction model in the gross sliding regime. We show how it can be se…
Light-weight robotic manipulators in combination with power wheelchairs can help to restore the mobility of people with disabilities. While such systems are available on the market, they typically are limited to fully manual control modes. In research, shared control methods are employed, to increas…
In robotic actuation a well identified and modeled friction behavior of the actuator components helps to significantly improve friction compensation, output torque estimation, and dynamic simulations. The friction of two components, i.e. a brush-less DC motor and a harmonic drive gear (HD) is invest…