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Subteaming and Adaptive Formation Control for Coordinated Multi-Robot Navigation

Deng, Zihao, Gao, Peng, Jose, Williard Joshua, Wigness, Maggie, Rogers, John, Reily, Brian, Reardon, Christopher, Zhang, Hao

arXiv.org Artificial Intelligence

Coordinated multi-robot navigation is essential for robots to operate as a team in diverse environments. During navigation, robot teams usually need to maintain specific formations, such as circular formations to protect human teammates at the center. However, in complex scenarios such as narrow corridors, rigidly preserving predefined formations can become infeasible. Therefore, robot teams must be capable of dynamically splitting into smaller subteams and adaptively controlling the subteams to navigate through such scenarios while preserving formations. To enable this capability, we introduce a novel method for SubTeaming and Adaptive Formation (STAF), which is built upon a unified hierarchical learning framework: (1) high-level deep graph cut for team splitting, (2) intermediate-level graph learning for facilitating coordinated navigation among subteams, and (3) low-level policy learning for controlling individual mobile robots to reach their goal positions while avoiding collisions. To evaluate STAF, we conducted extensive experiments in both indoor and outdoor environments using robotics simulations and physical robot teams. Experimental results show that STAF enables the novel capability for subteaming and adaptive formation control, and achieves promising performance in coordinated multi-robot navigation through challenging scenarios. More details are available on the project website: https://hcrlab.gitlab.io/project/STAF.


Dynamic Adversarial Resource Allocation: the dDAB Game

Shishika, Daigo, Guan, Yue, Marden, Jason R., Dorothy, Michael, Tsiotras, Panagiotis, Kumar, Vijay

arXiv.org Artificial Intelligence

This work proposes a dynamic and adversarial resource allocation problem in a graph environment, which is referred to as the dynamic Defender-Attacker Blotto (dDAB) game. A team of defender robots is tasked to ensure numerical advantage at every node in the graph against a team of attacker robots. The engagement is formulated as a discrete-time dynamic game, where the two teams reallocate their robots in sequence and each robot can move at most one hop at each time step. The game terminates with the attacker's victory if any node has more attacker robots than defender robots. Our goal is to identify the necessary and sufficient number of defender robots to guarantee defense. Through a reachability analysis, we first solve the problem for the case where the attacker team stays as a single group. The results are then generalized to the case where the attacker team can freely split and merge into subteams. Crucially, our analysis indicates that there is no incentive for the attacker team to split, which significantly reduces the search space for the attacker's winning strategies and also enables us to design defender counter-strategies using superposition. We also present an efficient numerical algorithm to identify the necessary and sufficient number of defender robots to defend a given graph. Finally, we present illustrative examples to verify the efficacy of the proposed framework.


GENIUS: A Novel Solution for Subteam Replacement with Clustering-based Graph Neural Network

Hu, Chuxuan, Zhou, Qinghai, Tong, Hanghang

arXiv.org Artificial Intelligence

Subteam replacement is defined as finding the optimal candidate set of people who can best function as an unavailable subset of members (i.e., subteam) for certain reasons (e.g., conflicts of interests, employee churn), given a team of people embedded in a social network working on the same task. Prior investigations on this problem incorporate graph kernel as the optimal criteria for measuring the similarity between the new optimized team and the original team. However, the increasingly abundant social networks reveal fundamental limitations of existing methods, including (1) the graph kernel-based approaches are powerless to capture the key intrinsic correlations among node features, (2) they generally search over the entire network for every member to be replaced, making it extremely inefficient as the network grows, and (3) the requirement of equal-sized replacement for the unavailable subteam can be inapplicable due to limited hiring budget. In this work, we address the limitations in the state-of-the-art for subteam replacement by (1) proposing GENIUS, a novel clustering-based graph neural network (GNN) framework that can capture team network knowledge for flexible subteam replacement, and (2) equipping the proposed GENIUS with self-supervised positive team contrasting training scheme to improve the team-level representation learning and unsupervised node clusters to prune candidates for fast computation. Through extensive empirical evaluations, we demonstrate the efficacy of the proposed method (1) effectiveness: being able to select better candidate members that significantly increase the similarity between the optimized and original teams, and (2) efficiency: achieving more than 600 times speed-up in average running time.


(Lead) NLP Data Scientist / ML Engineer, RegBrain

#artificialintelligence

CUBE uses AI and NLP to machine read the regulatory internet, at global scale. We collect, clean, standardise, translate, monitor, classify, and enrich regulatory data across 180 countries in over 60 languages. We've even built our own ontology of regulation--machine-driven and continuously refined by a team of subject matter experts. On a high level, CUBE uses AI to transform regulatory data into regulatory intelligence. And this is exactly where RegBrain comes in.


The pursuit of excellence in new-drug development

#artificialintelligence

We are living in a time of enormous scientific innovation and promise for improved human health. Our understanding of biology is expanding enormously alongside increased identification of novel targets and their associated modalities. Still, drug-development costs and timelines continue to rise, and the likelihood of success continues to fall. Collectively, the top 20 pharmaceutical companies spend approximately $60 billion on drug development each year, and the estimated average cost of bringing a drug to market (including drug failures) is now $2.6 billion--a 140 percent increase in the past ten years. 1 1. We believe the time is right for a true step change in drug development.