Publications by Alexandre Bernardino

1(st) Workshop on Maritime Computer Vision (MaCVi) 2023: Challenge Results

Alexandre Massoud Alahi, Alexandre Bernardino, Siddharth Gupta, Yang Song

The 1st Workshop on Maritime Computer Vision (MaCVi) 2023 focused on maritime computer vision for Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicle (USV), and organized several subchallenges in this domain: (i) UAV-based Maritime Object Detection, (ii) UAV-based Maritime Object Tracking, (iii) USV-based Maritime Obstacle Segmentation and (iv) USV-based Maritime Obstacle Detection. The subchallenges were based on the SeaDronesSee and MODS benchmarks. This report summarizes the main findings of the individual subchallenges and introduces a new benchmark, called SeaDronesSee Object Detection v2, which extends the previous benchmark by including more classes and footage. We provide statistical and qualitative analyses, and assess trends in the best-performing methodologies of over 130 submissions. The methods are summarized in the appendix. The datasets, evaluation code and the leaderboard are publicly available (https:// seadronessee.cs.uni-tuebingen.de/macvi).

IEEE COMPUTER SOC2023

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

Alexandre Bernardino, Jorg Conradt, Alessandro Crespi, Simon Lukas Hauser, Auke Ijspeert, Mehmet Hasan Mutlu, 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 challenge in most biomimetic aquatic robots. Event-driven sensors use a biologically inspired sensing strategy to eliminate the need for complete frame capture. Systems employing event-driven cameras enjoy reduced latencies, power consumption, bandwidth, and benefit from a large dynamic range. However, to the best of our knowledge, no work has been done to evaluate the performance of these devices in underwater robotics. This work proposes a robotic lamprey design capable of supporting computer vision, and uses this system to validate a computational neuron model for driving anguilliform swimming. The robot is equipped with two different types of cameras: frame-based and event-based cameras. These were used to stimulate the neural network, yielding goal-oriented swimming. Finally, a study is conducted comparing the performance of the computational model when driven by the two different types of camera. It was observed that event-based cameras improved the accuracy of swimming trajectories and led to significant improvements in the rate at which visual inputs were processed by the network.

2020

Roombots extended: Challenges in the next generation of self-reconfigurable modular robots and their application in adaptive and assistive furniture

Alexandre Bernardino, Auke Ijspeert, Mehmet Hasan Mutlu

2020

An Optimal Planning Framework to Deploy Self-Reconfigurable Modular Robots

Alexandre Bernardino, Simon Lukas Hauser, Auke Ijspeert, Hala Khodr, Mehmet Hasan Mutlu

Self-reconfiguration is a hard problem due to the high dimensionality of self-reconfigurable modular systems. Searchbased approaches offer complete and optimal solutions. However, naive search algorithms cannot directly solve self-reconfiguration tasks in reasonable time. In this letter, a transition model, a search heuristic, pruning strategies, and offline computations are proposed to advance performance of search-based self-reconfiguration methods. The targeted reconfiguration tasks include the reconfiguration of any distribution of modules, whether it is a complex structures or disconnected modules distributed in space. Hypothesized strategies are tested with conventional search methods to understand their contributions on complexity, optimality (minimum number of steps), completeness, and time efficiency. The whole framework is designed keeping hardware restrictions in mind and deployed on real Roombots hardware.

2019

Effects of passive and active joint compliance in quadrupedal locomotion

Alexandre Bernardino, Auke Ijspeert, Mehmet Hasan Mutlu

Compliance of the body has a crucial role on locomotion performance. The levels and the distribution of compliance should be well tuned to obtain efficient gait. The leg stiffness changes significantly even during different phases of a single gait cycle. This paper presents an experimental study on different passive and active limb compliance configurations. Each configuration is tested on flat, rough and inclined-rough surfaces, to analyze locomotion performance in diverse conditions. As the active compliance mechanism, Tegotae-based control is selected. Even though active compliance is not its primary use, we show that the Tegotae rule presents intriguing features that have potential to boost gait performance in various scenarios.

TAYLOR & FRANCIS LTD2018

Playdough to Roombots: Towards a Novel Tangible User Interface for Self-reconfigurable Modular Robots

Alexandre Bernardino, Simon Lukas Hauser, Auke Ijspeert, Mehmet Hasan Mutlu

One of the main strengths of self-reconfigurable modular robots (SRMR) is their ability to shape-shift and dynamically change their morphology. In the case of our SRMR system "Roombots", these shapes can be quite arbitrary for a great variety of tasks while the major utility is envisioned to be self-reconfigurable furniture. As such, the ideas and inspirations from users quickly need to be translated into the final Roombots shape. This involves a multitude of separate processes and - most importantly - requires an intuitive user interface. Our current approach led to the development of a tangible user interface (TUI) which involves 3D-scanning of a shape formed by modeling clay and the necessary steps to prepare the digitized model to be formed by Roombots. The system is able to generate a solution in less than two minutes for our target use as demonstrated with various examples.

IEEE COMPUTER SOC2018

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One of the main strengths of self-reconfigurable modular robots (SRMR) is their ability to shape-shift and dynamically change their morphology. In the case of our SRMR system “Roombots”, these shapes can be quite arbitrary for a great variety of tasks while the major utility is envisioned to be self-reconfigurable furniture. As such, the ideas and inspirations from users quickly need to be translated into the final Roombots shape. This involves a multitude of separate processes and - most importantly - requires an intuitive user interface. Our current approach led to the development of a tangible user interface (TUI) which involves 3D-scanning of a shape formed by modeling clay and the necessary steps to prepare the digitized model to be formed by Roombots. The system is able to generate a solution in less than two minutes for our target use as demonstrated with various examples.

2018

Effects of joint compliance in quadrupedal locomotion

Alexandre Bernardino, Simon Lukas Hauser, Auke Ijspeert, Mehmet Hasan Mutlu

2017

Self-reconfigurable modular robot interface using virtual reality: Arrangement of furniture made out of roombots modules

Alexandre Bernardino, Simon Lukas Hauser, Auke Ijspeert, Mehmet Hasan Mutlu

2017

Natural user interface for lighting control: Case study on desktop lighting using modular robots

Alexandre Bernardino, Stéphane Bonardi, Simon Lukas Hauser, Auke Ijspeert, Mehmet Hasan Mutlu, Massimo Vespignani

Roombots (RB) are self-reconfigurable modular robots designed to explore physical structure change by robotic reconfiguration and adaptive locomotion on structured grid environment or unstructured environment. The primary goal of RB is to create adaptive furniture. In this study, we propose a novel and user-friendly interface to control position and intensity of a mobile desk light using RB modules. In the proposed method, the user interacts with the RB with only hand/arm gestures. The user’s arm is tracked with a single Kinect having bird’s eye view. We demonstrate the effectiveness of the proposed interface in real hardware setup and discuss contributions of it.

Ieee2016