Publications related to A Dynamical System Approach to Realtime Obstacle Avoidance

Dynamical system approach to navigation around obstacles

In this article, we propose a dynamical system to avoid obstacles which are star shaped and simultaneously converge to a goal. The convergence is almost-global in a domain and the stationary points are identified explicitly. Our approach is based on the id ...

2024

Stability: a search for structure

Wouter Jongeneel

In this thesis we study stability from several viewpoints. After covering the practical importance, the rich history and the ever-growing list of manifestations of stability, we study the following. (i) (Statistical identification of stable dynamical syste ...

EPFL2024

Learning dynamical systems with bifurcations

Aude Billard, Ilaria Lauzana, Farshad Khadivar

Trajectory planning through dynamical systems (DS) provides robust control for robots and has found numerous applications from locomotion to manipulation. However, to date, DS for controlling rhythmic patterns are distinct from DS used to control point to ...

Elsevier2021

Automatic locking of a parametrically resonating, base-excited, nonlinear beam

Amit Yedidia Dolev

Described is a closed-loop control scheme capable of stabilizing a parametrically excited nonlinear structure in several vibration modes. By setting the relative phase between the spatially filtered response and the excitation, the open-loop unstable solut ...

SPRINGER2021

Topological Linear System Identification via Moderate Deviations Theory

Daniel Kuhn, Tobias Sutter, Wouter Jongeneel

Two dynamical systems are topologically equivalent when their phase-portraits can be morphed into each other by a homeomorphic coordinate transformation on the state space. The induced equivalence classes capture qualitative properties such as stability or ...

2022

Force Adaptation in Contact Tasks with Dynamical Systems

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

In many tasks such as finishing operations, achieving accurate force tracking is essential. However, uncertainties in the robot dynamics and the environment limit the force tracking accuracy. Learning a compensation model for these uncertainties to reduce ...

IEEE2020

A complex networks approach to traffic flow theory: measures and models

Leonardo Bellocchi

In this thesis, we developed a research direction that combines the theoretical concepts of complex networks with practical needs and applications in the field of transportation engineering. As a first objective we analyzed the phenomenon of congestion pr ...

EPFL2020

Invariant solutions underlying small- and large-scale structures in turbulent boundary layers

Sajjad Azimi

Flows of gases and liquids interacting with solid objects are often turbulent within a thin boundary layer. As energy dissipation and momentum transfer are dominated by the boundary layer dynamics, many engineering applications can benefit from an improved ...

EPFL2020

Out-of-equilibrium dynamical equations of infinite-dimensional particle systems. II. The anisotropic case under shear strain

Elisabeth Agoritsas

As an extension of the isotropic setting presented in the companion paper Agoritsas et al (2019 J. Phys. A: Math. Theor. 52 144002), we consider the Langevin dynamics of a many-body system of pairwise interacting particles in d dimensions, submitted to an ...

2019

A Dynamical System Approach to Motion and Force Generation in Contact Tasks

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

Many tasks require the robot to enter in contact with surfaces, be it to take support, to polish or to grasp an object. It is crucial that the robot controls forces both upon making contact and while in contact. While many solutions exist to control for co ...

Robotics: Science and Systems (RSS)2019

A Dynamical System Approach to Motion and Force Generation in Contact Tasks

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

Many tasks require the robot to enter in contact with surfaces, be it to take support, to polish or to grasp an object. It is crucial that the robot controls forces both upon making contact and while in contact. While many solutions exist to control for co ...

MIT PRESS2019

Learning Augmented Joint-Space Task-Oriented Dynamical Systems:A Linear Parameter Varying and Synergetic Control Approach

Aude Billard, Seyed Sina Mirrazavi Salehian, Nadia Barbara Figueroa Fernandez, Yonadav Goldwasser Shavit

In this paper, we propose an asymptotically stable joint-space dynamical system that captures desired behaviors in joint-space while stably converging towards a task-space attractor. To encode joint-space behaviors while meeting the stability criteria, the ...

2018

Compliant control of Uni/ Multi- robotic arms with dynamical systems

Seyed Sina Mirrazavi Salehian

Accomplishment of many interactive tasks hinges on the compliance of humans. Humans demonstrate an impressive capability of complying their behavior and more particularly their motions with the environment in everyday life. In humans, compliance emerges fr ...

EPFL2018

Incremental motion learning with locally modulated dynamical systems

Aude Billard, Klas Jonas Alfred Kronander

Dynamical Systems (DS) for robot motion modeling are a promising approach for efficient robot learning and control. Our focus in this paper is on autonomous dynamical systems, which represent a motion plan without dependency on time. We develop a method th ...

Elsevier2015

Noether's theorem for dissipative quantum dynamical semi-groups

Tudor Ratiu

Noether's theorem on constants of the motion of dynamical systems has recently been extended to classical dissipative systems (Markovian semi-groups) by Baez and Fong [J. Math. Phys. 54, 013301 (2013)]. We show how to extend these results to the fully quan ...

Amer Inst Physics2015

A General Family of Morphed Nonlinear Phase Oscillators with Arbitrary Limit Cycle Shape

Auke Ijspeert, Jesse van den Kieboom, Mostafa Ajallooeian

We present a general family of nonlinear phase oscillators which can exhibit arbitrary limit cycle shapes and infinitely large basins of attraction. This general family is the superset of familiar control methods like PD-control over a periodic reference, ...

Elsevier Science Bv2013

Dynamical Movement Primitives: Learning Attractor Models for Motor Behaviors

Auke Ijspeert

Nonlinear dynamical systems have been used in many disciplines to model complex behaviors, including biological motor control, robotics, perception, economics, traffic prediction, and neuroscience. While often the unexpected emergent behavior of nonlinear ...

Massachusetts Institute of Technology Press2013

Networks of Self-Adaptive Dynamical Systems

Max-Olivier Hongler, Julio Rodriguez

We discuss the adaptive behaviour of a collection of heterogeneous dynamical systems interacting via a weighted network. At each vertex, the network is endowed with a dynamical system with individual (initially different) control parameters governing the l ...

Oxford University Press2012

Networks of Self-Adaptive Dynamical Systems

Julio Rodriguez

The present work belongs to the vast body of research devoted to behaviors that emerge when homogeneous or heterogeneous agents interact. We adopt a stylized point of view in which the individual agents' activities can be assimilated into nonlinear dynamic ...

EPFL2011

Adaptive Frequency Oscillators and Applications

Auke Ijspeert, Ludovic Righetti, Jonas Buchli

In this contribution we present a generic mechanism to transform an oscillator into an adaptive frequency oscillator, which can then dynamically adapt its parameters to learn the frequency of any periodic driving signal. Adaptation is done in a dynamic way ...

2009