Publications by Ludovic Righetti

A unified framework for walking and running of bipedal robots

In this paper, we propose a novel framework capable of generating various walking and running gaits for bipedal robots. The main goal is to relax the fixed center of mass (CoM) height assumption of the linear inverted pendulum model (LIPM) and generate a w ...

IEEE2021

Slow-fast Dynamics of Strongly Coupled Adaptive Frequency Oscillators

Auke Ijspeert, Ludovic Righetti, Jonas Buchli

Oscillators have two main limitations: their synchronization properties are limited (i.e., they have a finite synchronization region) and they have no memory of past interactions (i.e., they return to their intrinsic frequency whenever the entraining signa ...

SIAM PUBLICATIONS2021

Kinematic and gait similarities between crawling human infants and other quadruped mammals

Auke Ijspeert, Ludovic Righetti

Crawling on hands and knees is an early pattern of human infant locomotion, which offers an interesting way of studying quadrupedalism in one of its simplest form. We investigate how crawling human infants compare to other quadruped mammals, especially pri ...

Frontiers Media Sa2015

Probabilistic Depth Image Registration incorporating Nonvisual Information

Aude Billard, Ludovic Righetti

In this paper, we derive a probabilistic registration algorithm for object modeling and tracking. In many robotics applications, such as manipulation tasks, nonvisual information about the movement of the object is available, which we will combine with the ...

Ieee2012

Towards simple control for complex, autonomous robotic applications: Combining discrete and rhythmic motor primitives

Auke Ijspeert, Ludovic Righetti, Sarah Dégallier Rochat, Sébastien Gay

Vertebrates are able to quickly adapt to new environments in a very robust, seemingly effortless way. To explain both this adaptivity and robustness, a very promising perspective in neurosciences is the modular approach to movement generation: Movements re ...

Springer Verlag2011

Compliant Leg Design for a Quadruped Robot

Auke Ijspeert, Ludovic Righetti, Simon Rutishauser, Alexander Spröwitz, Konstantinos Karakasiliotis

2009

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

Modelling the interplay of central pattern generation and sensory feedback in the neuromuscular control of running

Auke Ijspeert, Ludovic Righetti

2009

Experimental study of limit cycle and chaotic controllers for the locomotion of centipede robots

Auke Ijspeert, Ludovic Righetti

In this contribution we present a CPG (central pattern generator) controller based on coupled Rössler systems. It is able to generate both limit cycle and chaotic behaviors through bifurcation. We develop an experimental test bench to measure quantitativel ...

2008

Frequency analysis with coupled nonlinear oscillators

Auke Ijspeert, Ludovic Righetti, Jonas Buchli

We present a method to obtain the frequency spectrum of a signal with a nonlinear dynamical system. The dynamical system is composed of a pool of adaptive frequency oscillators with negative mean-field coupling. For the frequency analysis, the synchronizat ...

2008

A Dynamical System for Online Learning of Periodic Movements of Unknown Waveform and Frequency

Auke Ijspeert, Ludovic Righetti

2008

Control of legged locomotion using dynamical systems : design methods and adaptive frequency oscillators

Ludovic Righetti

Legged robots have gained an increased attention these past decades since they offer a promising technology for many applications in unstructured environments where the use of wheeled robots is clearly limited. Such applications include exploration and res ...

EPFL2008

A modular bio-inspired architecture for movement generation for the infant-like robot iCub

Auke Ijspeert, Ludovic Righetti, Sarah Dégallier Rochat

Movement generation in humans appears to be processed through a three-layered architecture, where each layer corresponds to a different level of abstraction in the representation of the movement. In this article, we will present an architecture reflecting ...

2008

Quadruped locomotion: from infants crawling to the design of pattern generators for quadruped robots

Auke Ijspeert, Ludovic Righetti

2008

Passive compliant quadruped robot using central pattern generators for locomotion control

Auke Ijspeert, Ludovic Righetti, Simon Rutishauser, Alexander Spröwitz

We present a new quadruped robot, “Cheetah”, featuring three-segment pantographic legs with passive compliant knee joints. Each leg has two degrees of freedom - knee and hip joint can be actuated using proximal mounted RC servo motors, force transmission t ...

2008

Pattern generators with sensory feedback for the control of quadruped locomotion

Auke Ijspeert, Ludovic Righetti

Central Pattern Generators (CPGs) are becoming a popular model for the control of locomotion of legged robots. Biological CPGs are neural networks responsible for the generation of rhythmic movements, especially locomotion. In robotics, a systematic way of ...

2008

Lower Body Realization of the Baby Humanoid - iCub

Auke Ijspeert, Ludovic Righetti

2007

iCub - The Design and Realization of an Open Humanoid Platform for Cognitive and Neuroscience Research

Auke Ijspeert, Ludovic Righetti

The development of robotic cognition and the advancement of understanding of human cognition form two of the current greatest challenges in robotics and neuroscience, respectively. The RobotCub project aims to develop an embodied robotic child (iCub) with ...

2007

Hand placement during quadruped locomotion in a humanoid robot: A dynamical system approach

Auke Ijspeert, Ludovic Righetti, Sarah Dégallier Rochat

Locomotion on an irregular surface is a challenging task in robotics. Among different problems to solve to obtain robust locomotion, visually guided locomotion and accurate foot placement are of crucial importance. Robust controllers able to adapt to senso ...

2007

Design methodologies for central pattern generators: towards 'intelligent' locomotion in robots

Auke Ijspeert, Ludovic Righetti

2006