Cyrill Silvan Baumann

Related publications (6)

A Noise-Resistant Mixed-Discrete Particle Swarm Optimization Algorithm for the Automatic Design of Robotic Controllers

Cyrill Silvan Baumann, Alcherio Martinoli

The automatic design of well-performing robotic controllers is still an unsolved problem due to the inherently large parameter space and noisy, often hard-to-define performance metrics, especially when sequential tasks need to be accomplished. Distal control architectures, which combine precoded basic behaviors into a (probabilistic) finite state machine offer a promising solution to this problem. In this paper, we enhance a Mixed-Discrete Particle Swarm Optimization (MDPSO) algorithm with an Optimal Computing Budget Allocation (OCBA) scheme to automatically synthesize distal control architectures. We benchmark MDPSO-OCBA’s performance against the original MDPSO as well as the Iterated F-Race (IRACE) and the Mesh Adaptive Direct Search (MADS) algorithms on both a benchmark function with different noise levels and design problems of distal control architectures. More specifically, we evaluate the algorithms using high-fidelity simulations in three increasingly challenging scenarios involving parallel and sequential tasks. Additionally, the best performing controller generated in simulation by each optimization algorithm is compared with a manually designed solution and validated with physical experiments. The analysis on the benchmark function with different noise levels demonstrates MDPSO-OCBA’s high robustness to noise. The comparison on the robotic control design problems shows that, without any meta-parameter tuning, MDPSO-OCBA is able to generate the best performing control architectures overall, closely followed by IRACE. They significantly outperform MADS for the more complex and noisier scenarios, resulting in competitive controllers in comparison to the manually designed one.

2022

Hybrid Flock - Formation Control Algorithms

Cyrill Silvan Baumann, Alcherio Martinoli, Jonas Perolini, Emna Tourki

Two prominent categories for achieving coordinated multirobot displacement are flocking and navigation in formation. Both categories have their own body of literature and characteristics, including their respective advantages and disadvantages. While typically, they are treated separately, we believe that a combination of flock and formation control represents a promising algorithmic solution. Such an algorithm could leverage a combination of characteristics of both categories best suited for a given situation. In this work, we therefore propose two distributed algorithms, able to gradually and reversibly shift between flocking and formation behaviors using a single parameter W. We evaluate them using both simulated and real robots with and without the presence of obstacles.We find that both algorithms successfully trade off flock density for formation error. Furthermore, using a funnel experiment as application case study, we demonstrate that an adaptive shift between flock and formation behavior, using a simple method to define W in real-time using exclusively on-board resources, results in a statistically relevant reduction of traversing time in comparison to a non-adaptive formation control algorithm.

2022

Leveraging Multi-Level Modelling to Automatically Design Behavioral Arbitrators in Robotic Controllers

Cyrill Silvan Baumann, Hugo Richard Birch, Alcherio Martinoli

Automatic control design for robotic systems is becoming more and more popular. However, this usually involves a significant computational cost, due to the expensive and noisy evaluation of candidate solutions through highfidelity simulation or even real hardware. This work aims at reducing the computational cost of automatic design of behavioral arbitrators through the introduction of a two-step approach. In the first step, the structure of the finite state machine governing the behavioral arbitrator is optimized. To this purpose, a more abstracted model of the robotic system is leveraged in order to significantly reduce the computational cost. In the second step, the close-to-hardware, behavioral parameters are fine-tuned using a high-fidelity model. We show that, for a scenario involving a single robot and multiple tasks to be solved sequentially, using the proposed method results in a significant decrease of the computational cost while reaching the same controller performance both in simulation and reality.

2022

In this work, we address the design of tightly integrated control, estimation, and allocation algorithms allowing a group of robots to move collectively. For doing so, we leverage a modular framework that allows us to define precisely the needed functional components and thus consider and compare multiple algorithmic solutions for the same module. We demonstrate the effectiveness of such a framework through multiple spatial coordination challenges carried out both in simulation and reality and leveraging different distributed control laws (graph-based and behavior-based controllers). Moreover, we investigate the impact of different localization and communication constraints as well as that of real-time switching of control laws on selected coordination metrics. Finally, we also introduce additional algorithmic components for demonstrating further the modularity of the framework. We find that defining the modularity based on functionality is a very effective way to enable algorithm benchmarking and discover possible improvements of the overall software stack while at the same time being agnostic to the underlying hardware and middleware resources. This is an especially welcome feature in case of severely resource-constrained multi-robot systems. Moreover, an important benefit of such design process is that the resulting distributed control algorithms are very robust to the considered noise sources and amplitudes as well as to the diverse types of challenges considered.

2021

De la stratégie urbaine aux détails de construction, le développement de Microcity à Neuchâtel s’inscrit dans une recherche de cohérence globale et intégrée en matière de durabilité.Un des traits communs à ces multiples axes d’action est la notion d’hybridation, en d’autres termes la recherche de synergie et d’optimisation par l’association de concepts, de technologies et de matériaux différents. Par sa situation stratégique, le bâtiment contribue au processus de densification de la ville de Neuchâtel, caractérisé notamment par la création de nouveaux pôles à proximité immédiate des arrêts de transports publics. Il s’intègre comme une polarité signifiante dans la morphologie urbaine. Les interactions entre la nouvelle pièce urbaine, les bâtiments existants, les espaces extérieurs et des parcours de mobilité douce permettent de créer une entité cohérente, dont l’identité valorise l’ensemble du quartier.

2014

Coupled seismogenic geohazards in Alpine regions

Cyrill Silvan Baumann, Fabrice Dupray, Alessio Ferrari, Amin Karbassi, Lyesse Laloui, Pierino Lestuzzi, Clotaire Michel

COupled seismogenic GEohazards in Alpine Regions (COGEAR) is an interdisciplinary natural hazard project investigating the hazard chain induced by earthquakes. It addresses tectonic processes and the related variability of seismicity in space and time, earthquake forecasting and short-term precursors, and strong ground motion as a result of source and complex path effects. We study non-linear wave propagation phenomena, liquefaction and triggering of landslides in soil and rock, as well as earthquake-induced snow avalanches. The Valais, and in particular parts of the Rhone, Visper, and Matter valleys have been selected as study areas. Tasks include detailed field investigations, development and application of numerical modeling techniques, assessment of the susceptibility to seismically induced effects, and installation of different monitoring systems to test and validate our models. These systems are for long-term operation and include a continuous GPS and seismic networks, a test installation for observing earthquake precursors, and a system to study site-effects and non-linear phenomena in two test areas (Visp, St. Niklaus / Randa). Risk-related aspects relevant for buildings and lifelines are also considered.

2012