Publications by Alessandro Crespi

A smoothed particle hydrodynamics framework for fluid simulation in robotics

Auke Ijspeert, Alessandro Crespi, Jonathan Patrick Arreguit O'Neill

Simulation is a core component of robotics workflows that can shed light on the complex interplay between a physical body, the environment and sensory feedback mechanisms in silico. To this goal several simulation methods, originating in rigid body dynamic ...

Elsevier2025

Social isolation shortens lifespan through oxidative stress in ants

Alessandro Crespi, Laurent Keller

Social isolation negatively affects health, induces detrimental behaviors, and shortens lifespan in social species. Little is known about the mechanisms underpinning these effects because model species are typically short-lived and non-social. Using coloni ...

Nature Research2023

Two simple movement mechanisms for spatial division of labour in social insects

Alessandro Crespi

Ant and honeybee workers specialize on certain tasks and also on zones within the nest; but how do they avoid straying into the wrong zone? The authors conduct automated tracking experiments following thousands of individuals, revealing that workers use co ...

Nature Portfolio2022

A Neuro-Inspired Computational Model for a Visually Guided Robotic Lamprey Using Frame and Event Based Cameras

Auke Ijspeert, Alessandro Crespi, Alexandre Bernardino, Mehmet Hasan Mutlu, Simon Lukas Hauser, Jorg Conradt, Ibrahim Youssef Youssef

The computational load associated with computer vision is often prohibitive, and limits the capacity for on-board image analysis in compact mobile robots. Replicating the kind of feature detection and neural processing that animals excel at remains a chall ...

2020

Reproducing Five Motor Behaviors in a Salamander Robot With Virtual Muscles and a Distributed CPG Controller Regulated by Drive Signals and Proprioceptive Feedback

Auke Ijspeert, Alessandro Crespi, Jérémie Knüsel

Diverse locomotor behaviors emerge from the interactions between the spinal central pattern generator (CPG), descending brain signals and sensory feedback. Salamander motor behaviors include swimming, struggling, forward underwater stepping, and forward an ...

2020

Social network plasticity decreases disease transmission in a eusocial insect

Alessandro Crespi, Laurent Keller

Animal social networks are shaped by multiple selection pressures, including the need to ensure efficient communication and functioning while simultaneously limiting disease transmission. Social animals could potentially further reduce epidemic risk by alt ...

American Association for the Advancement of Science2018

Environmental Monitoring using Autonomous Vehicles: A Survey of Recent Searching Techniques

Auke Ijspeert, Alessandro Crespi

Autonomous vehicles are becoming an essential tool in a wide range of environmental applications that include ambient data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. Among these applications, pollution source locali ...

Elsevier2017

Automated computer-based detection of encounter behaviours in groups of honeybees

Alessandro Crespi, Laurent Keller

Honeybees form societies in which thousands of members integrate their behaviours to act as a single functional unit. We have little knowledge on how the collaborative features are regulated by workers' activities because we lack methods that enable collec ...

Springer Nature2017

Envirobot: A Bio-Inspired Environmental Monitoring Platform

Auke Ijspeert, Alessandro Crespi

Autonomous marine vehicles are becoming essential tools in aquatic environmental monitoring systems, and can be used for instance for data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. In this work, we present an uncon ...

Ieee2016

Optical properties of waveguide-coupled nanowires for sub-wavelength detection in microspectrometer applications

Alessandro Crespi, Toralf Scharf

In this paper we experimentally investigate optical interactions between gold nanowires and fs-laser written waveguides in a view of applications for stationary-wave integrated Fourier-transform spectrometers in a movable mirror configuration. For this pur ...

European Optical Society2015

Salamandra Robotica II: An Amphibious Robot to Study Salamander-Like Swimming and Walking Gaits

André Guignard, Auke Ijspeert, Alessandro Crespi, Konstantinos Karakasiliotis

In this paper, we present Salamandra robotica II: an amphibious salamander robot that is able to walk and swim. The robot has four legs and an actuated spine that allow it to perform anguilliform swimming in water and walking on the ground. The paper first ...

Ieee-Inst Electrical Electronics Engineers Inc2013

Tracking Individuals Shows Spatial Fidelity Is a Key Regulator of Ant Social Organization

Alessandro Crespi

Ants live in organized societies with a marked division of labor among workers, but little is known about how this division of labor is generated. We used a tracking system to continuously monitor individually tagged workers in six colonies of the ant Camp ...

American Association for the Advancement of Science2013

Gait transitions between swimming and walking in salamander: lessons from numerical modeling and robotics

Auke Ijspeert, Alessandro Crespi, Jérémie Knüsel, Konstantinos Karakasiliotis

Oxford University Press2013

Online optimization of swimming and crawling in an amphibious snake robot

Auke Ijspeert, Alessandro Crespi

An important problem in the control of locomotion of robots with multiple degrees of freedom (e.g., biomimetic robots) is to adapt the locomotor patterns to the properties of the environment. This article addresses this problem for the locomotion of an amp ...

2008

Controlling swimming and crawling in a fish robot using a central pattern generator

Auke Ijspeert, Alessandro Crespi, Daisy Lachat, Ariane Pasquier

Online trajectory generation for robots with multiple degrees of freedom is still a difficult and unsolved problem, in particular for non-steady state locomotion, that is, when the robot has to move in a complex environment with continuous variations of th ...

2008

Design and control of amphibious robots with multiple degrees of freedom

Alessandro Crespi

This thesis presents the design and realization of two generations of robot elements that can be assembled together to construct amphibious mobile robots. These elements, designed to be individually waterproof and having their own battery, motor controller ...

EPFL2007

From swimming to walking with a salamander robot driven by a spinal cord model

Auke Ijspeert, Alessandro Crespi

The transition from aquatic to terrestrial locomotion was a key development in vertebrate evolution. We present a spinal cord model and its implementation in an amphibious salamander robot that demonstrates how a primitive neural circuit for swimming can b ...

American Association for the Advancement of Science2007

Online trajectory generation in an amphibious snake robot using a lamprey-like central pattern generator model

Auke Ijspeert, Alessandro Crespi

This article presents a control architecture for controlling the locomotion of an amphibious snake/lamprey robot capable of swimming and serpentine locomotion. The control architecture is based on a central pattern generator (CPG) model inspired from the n ...

IEEE2007

AmphiBot II: An Amphibious Snake Robot that Crawls and Swims using a Central Pattern Generator

Auke Ijspeert, Alessandro Crespi

2006

BoxyBot: a swimming and crawling fish robot controlled by a central pattern generator

Auke Ijspeert, Alessandro Crespi, Daisy Lachat

2006