arXiv subjects

Alexandre Pacheco

Publications and source records attributed to Alexandre Pacheco.

4 recordsLinked to original sources

arXiv2026

Self-governed access control in open robot swarms using a blockchain-based DAO

Robot swarms harness simple, local interactions among many individually limited robots to produce complex, coordinated collective behavior, making them valuable across domains from agriculture to disaster response. We envision the next frontier for such swarms as open swarms, in which robots join or leave the swarm dynamically at runtime. The ability to dynamically adjust swarm size has been shown to be beneficial, for instance by reducing inconsistencies and network partitioning, especially under sparse connectivity or in complex environments, ultimately improving task performance. For practical deployment, however, open swarms requires governance, particularly protection against Byzantine behavior (i.e., faulty or malicious robots), since allowing robots to join freely also makes the swarm easier to infiltrate. Blockchain technology has recently been incorporated into robot swarms, offering secure, decentralized coordination and improved resilience, though largely in closed settings with a fixed, predetermined membership. In this work, we extend these benefits to open swarms by introducing robot swarms governed by a blockchain-based decentralized autonomous organization (DAO), in which the swarm regulates itself using autonomous rules encoded in smart contracts. We outline several DAO-based governance mechanisms for robot swarms, depending on the needs of the application, and present a proof-of-concept implementation of a simple DAO that regulates swarm membership and prevents Byzantine infiltration. Our simulation results and real-robot validations show that DAO-governed access control and robot removal can maintain proper swarm functioning while keeping the number of Byzantine robots within acceptable limits.

cs.RO↗

arXiv2025

Swarm Oracle: Trustless Blockchain Agreements through Robot Swarms

Blockchain consensus, rooted in the principle ``don't trust, verify'', limits access to real-world data, which may be ambiguous or inaccessible to some participants. Oracles address this limitation by supplying data to blockchains, but existing solutions may reduce autonomy, transparency, or reintroduce the need for trust. We propose Swarm Oracle: a decentralized network of autonomous robots -- that is, a robot swarm -- that use onboard sensors and peer-to-peer communication to collectively verify real-world data and provide it to smart contracts on public blockchains. Swarm Oracle leverages the built-in decentralization, fault tolerance and mobility of robot swarms, which can flexibly adapt to meet information requests on-demand, even in remote locations. Unlike typical cooperative robot swarms, Swarm Oracle integrates robots from multiple stakeholders, protecting the system from single-party biases but also introducing potential adversarial behavior. To ensure the secure, trustless and global consensus required by blockchains, we employ a Byzantine fault-tolerant protocol that enables robots from different stakeholders to operate together, reaching social agreements of higher quality than the estimates of individual robots. Through extensive experiments using both real and simulated robots, we showcase how consensus on uncertain environmental information can be achieved, despite several types of attacks orchestrated by large proportions of the robots, and how a reputation system based on blockchain tokens lets Swarm Oracle autonomously recover from faults and attacks, a requirement for long-term operation.

cs.RO↗

arXiv2024

Securing Federated Learning in Robot Swarms using Blockchain Technology

Federated learning is a new approach to distributed machine learning that offers potential advantages such as reducing communication requirements and distributing the costs of training algorithms. Therefore, it could hold great promise in swarm robotics applications. However, federated learning usually requires a centralized server for the aggregation of the models. In this paper, we present a proof-of-concept implementation of federated learning in a robot swarm that does not compromise decentralization. To do so, we use blockchain technology to enable our robot swarm to securely synchronize a shared model that is the aggregation of the individual models without relying on a central server. We then show that introducing a single malfunctioning robot can, however, heavily disrupt the training process. To prevent such situations, we devise protection mechanisms that are implemented through secure and tamper-proof blockchain smart contracts. Our experiments are conducted in ARGoS, a physics-based simulator for swarm robotics, using the Ethereum blockchain protocol which is executed by each simulated robot.

cs.RO↗

arXiv2024

Toychain: A Simple Blockchain for Research in Swarm Robotics

This technical report describes the implementation of Toychain: a simple, lightweight blockchain implemented in Python, designed for ease of deployment and practicality in robotics research. It can be integrated with various software and simulation tools used in robotics (we have integrated it with ARGoS, Gazebo, and ROS2), and also be deployed on real robots capable of Wi-Fi communications. The Toychain package supports the deployment of smart contracts written in Python (computer programs that can be executed by and synchronized across a distributed network). The nodes in the blockchain can execute smart contract functions by broadcasting transactions, which update the state of the blockchain upon agreement by all other nodes. The conditions for this agreement are established by a consensus protocol. The Toychain package allows for custom implementations of the consensus protocol, which can be useful for research or meeting specific application requirements. Currently, Proof-of-Work and Proof-of-Authority are implemented.

cs.RO↗