Christian Ott
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View article: Unidirectional virtual inerter for high-bandwidth robot motion control
Unidirectional virtual inerter for high-bandwidth robot motion control Open
This paper introduces a Unidirectional Virtual Inerter (UVI) as a novel feedback control element in conjunction with a traditional PD controller for high-bandwidth robot motion control. Designed to harness the beneficial properties of a ph…
View article: Experimental Comparison of Whole-Body Control Formulations for Humanoid Robots in Task Acceleration and Task Force Spaces
Experimental Comparison of Whole-Body Control Formulations for Humanoid Robots in Task Acceleration and Task Force Spaces Open
This paper studies the experimental comparison of two different whole-body control formulations for humanoid robots: inverse dynamics whole-body control (ID-WBC) and passivity-based whole-body control (PB-WBC). The two controllers fundamen…
View article: Learning Swing-up Maneuvers for a Suspended Aerial Manipulation Platform in a Hierarchical Control Framework
Learning Swing-up Maneuvers for a Suspended Aerial Manipulation Platform in a Hierarchical Control Framework Open
In this work, we present a novel approach to augment a model-based control method with a reinforcement learning (RL) agent and demonstrate a swing-up maneuver with a suspended aerial manipulation platform. These platforms are targeted towa…
View article: Realtime Limb Trajectory Optimization for Humanoid Running Through Centroidal Angular Momentum Dynamics
Realtime Limb Trajectory Optimization for Humanoid Running Through Centroidal Angular Momentum Dynamics Open
One of the essential aspects of humanoid robot running is determining the limb-swinging trajectories. During the flight phases, where the ground reaction forces are not available for regulation, the limb swinging trajectories are significa…
View article: An Efficient Numerical Function Optimization Framework for Constrained Nonlinear Robotic Problems
An Efficient Numerical Function Optimization Framework for Constrained Nonlinear Robotic Problems Open
View article: Learning Swing-up Maneuvers for a Suspended Aerial Manipulation Platform in a Hierarchical Control Framework
Learning Swing-up Maneuvers for a Suspended Aerial Manipulation Platform in a Hierarchical Control Framework Open
View article: Extending humanoids DCM-based walking to push heavy objects while walking
Extending humanoids DCM-based walking to push heavy objects while walking Open
View article: Koopman-based improvement of the closed-loop response of controlled articulated soft robots
Koopman-based improvement of the closed-loop response of controlled articulated soft robots Open
View article: Enhancing Model-Based Step Adaptation for Push Recovery through Reinforcement Learning of Step Timing and Region
Enhancing Model-Based Step Adaptation for Push Recovery through Reinforcement Learning of Step Timing and Region Open
This paper introduces a new approach to enhance the robustness of humanoid walking under strong perturbations, such as substantial pushes. Effective recovery from external disturbances requires bipedal robots to dynamically adjust their st…
View article: Coherent all X-ray four wave mixing at core shell resonances
Coherent all X-ray four wave mixing at core shell resonances Open
Nonlinear wave mixing in the X-ray range can provide valuable insights into the structural and electron dynamics of atomic and molecular systems on ultrafast time scales, with state- and site-selectivity and atomic resolution. This promisi…
View article: An experimental study of the sensorized strain wave gear RT1-T and its capabilities for torque control in robotic joints
An experimental study of the sensorized strain wave gear RT1-T and its capabilities for torque control in robotic joints Open
The idea of sensorizing a strain wave gear to measure the transmitted torque has been reported since the 1980s. The strain in the elastic flex spline is typically measured by strain gages attached to it. The resulting voltages relate to th…
View article: Capturing Nonlinear Electron Dynamics with Fully Characterised Attosecond X-ray Pulses
Capturing Nonlinear Electron Dynamics with Fully Characterised Attosecond X-ray Pulses Open
Attosecond X-ray pulses are the key to studying electron dynamics at their natural timescale in specifically targeted electronic states. They promise to build the conceptual bridge between physical and chemical photo-reaction processes. Fr…
View article: Shared Autonomy via Variable Impedance Control and Virtual Potential Fields for Encoding Human Demonstration
Shared Autonomy via Variable Impedance Control and Virtual Potential Fields for Encoding Human Demonstration Open
This article introduces a framework for complex human-robot collaboration tasks, such as the co-manufacturing of furniture. For these tasks, it is essential to encode tasks from human demonstration and reproduce these skills in a compliant…
View article: Observer-based Controller Design for Oscillation Damping of a Novel Suspended Underactuated Aerial Platform
Observer-based Controller Design for Oscillation Damping of a Novel Suspended Underactuated Aerial Platform Open
In this work, we present a novel actuation strategy for a suspended aerial platform. By utilizing an underactuation approach, we demonstrate the successful oscillation damping of the proposed platform, modeled as a spherical double pendulu…
View article: Impact Analysis for the Planning of Targeted Non-Slippage Impacts of Robot Manipulators
Impact Analysis for the Planning of Targeted Non-Slippage Impacts of Robot Manipulators Open
Some impact tasks for robot manipulators, like stamping, demand that the end-effector does not slip off the target at the contact transition. We refer to this class of impacts as targeted non-slippage impacts and provide solutions to perfo…
View article: Agile and Dynamic Standing-Up Control for Humanoids Using 3D Divergent Component of Motion in Multi-Contact Scenario
Agile and Dynamic Standing-Up Control for Humanoids Using 3D Divergent Component of Motion in Multi-Contact Scenario Open
Standing-up is a task that humanoids need to be able to perform in order to be employed in real-world scenarios. This letter proposes a new robust strategy for a humanoid to stand up in challenging scenarios where no completely preplanned …
View article: Determinants of arterial stiffness in patients with type 2 diabetes mellitus: a cross sectional analysis
Determinants of arterial stiffness in patients with type 2 diabetes mellitus: a cross sectional analysis Open
In patients with type 2 diabetes mellitus (T2DM) arterial stiffness is associated with increased cardiovascular and total mortality. Little is known about determinants of arterial stiffness in clinical routine. Identification of potential …
View article: Table of Contents
Table of Contents Open
As the official means of communication for the IEEE Control Systems Society, IEEE Control Systems publishes interesting, useful, and informative material on all aspects of control system technology for the benefit of control educators, pra…
View article: Hierarchical Whole-body Control of the cable-Suspended Aerial Manipulator endowed with Winch-based Actuation
Hierarchical Whole-body Control of the cable-Suspended Aerial Manipulator endowed with Winch-based Actuation Open
During operation, aerial manipulation systems are affected by various disturbances. Among them is a gravitational torque caused by the weight of the robotic arm. Common propeller-based actuation is ineffective against such disturbances bec…
View article: Laser control of an excited-state vibrational wave packet in neutral H$_2$
Laser control of an excited-state vibrational wave packet in neutral H$_2$ Open
We observe and control a molecular vibrational wave packet in an electronically excited state of the neutral hydrogen molecule. In an extreme-ultraviolet (XUV) transient-absorption experiment we launch a vibrational wave packet in the $D ^…
View article: Passive arbitration in adaptive shared control of robots with variable force and stiffness scaling
Passive arbitration in adaptive shared control of robots with variable force and stiffness scaling Open
View article: EigenMPC: An Eigenmanifold-Inspired Model-Predictive Control Framework for Exciting Efficient Oscillations in Mechanical Systems
EigenMPC: An Eigenmanifold-Inspired Model-Predictive Control Framework for Exciting Efficient Oscillations in Mechanical Systems Open
This paper proposes a Nonlinear Model-Predictive Control (NMPC) method\ncapable of finding and converging to energy-efficient regular oscillations,\nwhich require no control action to be sustained. The approach builds up on the\nrecently d…
View article: Waldböden – intakt und funktional
Waldböden – intakt und funktional Open
Forest soils in focusA naturally grown and intact forest soil is invaluable.It provides clean drinking water, protects against floods, is the habitat of countless organisms, and is the basis for wood production.Forest soils play a particul…
View article: Resolving Vibrations in a Polyatomic Molecule with Femtometer Precision
Resolving Vibrations in a Polyatomic Molecule with Femtometer Precision Open
We measure molecular vibrations with femtometer precision using time-resolved x-ray absorption spectroscopy. For a demonstration, a Raman process excites the A$_{1g}$ mode in gas-phase SF$_6$ molecules with an amplitude of $\approx50$ fm, …
View article: Passive Decoupled Multi-Task Controller for Redundant Robots
Passive Decoupled Multi-Task Controller for Redundant Robots Open
Kinematic redundancy in robots makes it possible to execute several control tasks simultaneously. As some tasks are usually more important than others, it is reasonable to dynamically decouple them in order to ensure their execution in a h…
View article: Passive Decoupled Multi-Task Controller for Redundant Robots
Passive Decoupled Multi-Task Controller for Redundant Robots Open
Kinematic redundancy in robots makes it possible to execute several control tasks simultaneously. As some tasks are usually more important than others, it is reasonable to dynamically decouple them in order to ensure their execution in a h…
View article: From underactuation to quasi‐full actuation: Aiming at a unifying control framework for articulated soft robots
From underactuation to quasi‐full actuation: Aiming at a unifying control framework for articulated soft robots Open
We establish a structure preserving state and input transformation that allows a class of underactuated Euler Lagrange systems to be treated as “quasi‐fully” actuated. In this equivalent quasi‐fully actuated form, the system is characteriz…
View article: An Experimental Study on MPC based Joint Torque Control for Flexible Joint Robots
An Experimental Study on MPC based Joint Torque Control for Flexible Joint Robots Open
This paper presents an experimental evaluation of joint torque control in a flexible joint robot using a model predictive control approach. The control of elastic robots is challenging due to the underactuated nature of the connected link …
View article: Dynamics and Control of a Reconfigurable Multi-Arm Robot for In-Orbit Assembly
Dynamics and Control of a Reconfigurable Multi-Arm Robot for In-Orbit Assembly Open
In this paper, a passivity-based controller is proposed for a reconfigurable multi-arm system, which is employed for in-orbit assembly. The reconfigurable system is composed of multiple anthropomorphic arms which can be connected to a tors…
View article: Control of an Orbital Manipulator with Reaction Wheels for On-orbit Servicing
Control of an Orbital Manipulator with Reaction Wheels for On-orbit Servicing Open
In on-orbit servicing missions, a spacecraft equipped with a manipulator arm grasps a client satellite. Afterwards, the momentum-dumping phase follows and the manipulator can be utilized for servicing tasks. Once the momentum has been dump…