CO-SEARCH

Equations informed and data-driven approaches for collective optimal search in complex flows

Founding Body: MUR
Total grant: € 109k *
Principal Investigator: Massimo Cencini
Other participants: Department of Physics University of Rome “Tor Vergata” (L. Biferale)
Project duration: 2023-2025
Website:

Finanziato Dall’unione Europea – Next Generation EU – Piano Nazionale Di Ripresa E Resilienza (PNRR) – Missione 4 “Istruzione E Ricerca” – Componente C2 Investimento 1.1.”Fondo Per Il Programma Nazionale Di Ricerca E Progetti Di Rilevante Interesse Nazionale (PRIN)
* importo finanziamento pari a 109.258,00 €

Abstract
Locating a source of dangerous/interesting chemical or physical signals transported by a complex turbulent environment is a key, fundamental problem with applications to geophysics, biophysics, robotics and environmental sciences. Multiple methodologies, based on heuristics, information theory, data-driven machine-learning or brute-force, equation-based, numerics have been developed in the last decades. None of them guarantees success. In most applications, partial observability and/or poor knowledge of the environment are additional important bottlenecks. As a matter of fact, the problem of optimally locating (in the shortest time or with minimal failing rate) a localized source in a turbulent flow is an open problem. Only proofs-of-concept exist, mainly based on simplified environmental models, assuming unrealistic full maneuverability or all-to-all communication among the searching agents.

CO-SEARCH aims to make quantitative advancements in two ways. First, we benchmark and validate in realistic complex flows the existing search algorithms, which has never been systematically attempted before. Second, we explore novel collective policies to locate multiple sources and learn about the environmental conditions by inferring the optimal model parameters. Both phenomenological and equation-informed approaches, combined with data-driven methods will be used.

As a glimpse into the problem’s complexity, imagine a single or a group of animals/robots trying to locate a source only relying on the emitted signals conveyed by a turbulent flow. This generates intermittent, highly non-Gaussian, concentration fields with randomly oriented gradients and wide empty regions. Gradient-ascent approaches, such as chemotaxis, are clearly doomed to fail. Two different strategies exist: (i) phenomenological/bio-mimetic, where the agent reacts with hardwired moves; (ii) model-based/cognitive, where some knowledge of the environment allows the agent to update its belief on the source location and decide how to move accordingly. Infotaxis, performing a gradient ascent in information, is one of the most promising recent solutions. Still, its efficiency in complex flows is largely unknown. Even less is known whether collective search offers better performances, with affordable computational costs, already for simplified set-ups. Cognitive strategies can become inefficient due to model errors, unavoidable in realistic environments. Whether multi-agents policies can mitigate such epistemic limitation by the many wrongs principle or by on-the-fly model refinement is unexplored as of now.

Furthermore, CO-SEARCH aims at leaving a long-term legacy of its scientific advancements by creating an open-database for single and multiple emitting sources in complex flows. The decades-long collaboration of the groups at CNR and Tor Vergata University, together with a well established international network, ensure the highest chance of success.

Partner in the project: CNR-ISC (M. Cencini) & Department of Physics University of Rome “Tor Vergata” (L. Biferale)