{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,2]],"date-time":"2026-03-02T17:11:50Z","timestamp":1772471510056,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T00:00:00Z","timestamp":1771977600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"MUR","award":["H53D23000610006"],"award-info":[{"award-number":["H53D23000610006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Robotics"],"abstract":"<jats:p>In this paper, we propose a distributed admittance control framework for joint manipulation of objects by multiple robotic arms that addresses the challenges of human\u2013robot interaction. The system is developed to control the joint transportation of an object by N Franka Emika Panda robots (validated with up to four in simulations) using external human force estimation in a distributed manner without relying on centralized computation or force sensors. We integrate a hybrid observer by combining a distributed force estimator with a nonlinear disturbance observer (NDOB) to achieve accurate human force estimation and minimize estimation errors in simulations. Adaptive radial basis function neural networks (RBFNNs) are employed to dynamically adjust the damping and inertia parameters, enhancing the system\u2019s adaptability and stability. Event-based communication minimizes network bandwidth usage, while consensus protocols ensure synchronization of state estimates across robots. Unlike conventional methods, the proposed observer operates in a fully sensorless manner: no human-force measurements are required. The estimation relies solely on locally available robot states, maintaining high accuracy while reducing system complexity. The framework demonstrates scalability to multiple robots, enhancing robustness in distributed settings. Simulation results show superior performance in terms of path tracking, force estimation accuracy, and communication efficiency compared to centralized approaches. Specifically, the event-triggered strategy reduces communication messages by approximately 70% compared to always-connected mode while maintaining comparable RMSE in position (9.97\u00d710\u22125 vs. 7.39\u00d710\u22125) and velocity (2.52\u00d710\u22125 vs. 3.76\u00d710\u22125), outperforming periodic communication.<\/jats:p>","DOI":"10.3390\/robotics15030048","type":"journal-article","created":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T13:37:37Z","timestamp":1772026657000},"page":"48","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Event-Triggered Distributed Variable Admittance Control for Human\u2013Multi-Robot Collaborative Manipulation"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8854-0236","authenticated-orcid":false,"given":"Mohammad","family":"Jahani Moghaddam","sequence":"first","affiliation":[{"name":"Department of Electrical and Information Engineering, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, Frosinone, Italy"},{"name":"Department of Electrical Engineering, Lan.C., Islamic Azad University, Student Street, Langarud 4471311127, Iran"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9750-8289","authenticated-orcid":false,"given":"Filippo","family":"Arrichiello","sequence":"additional","affiliation":[{"name":"Department of Electrical and Information Engineering, University of Cassino and Southern Lazio, Via G. Di Biasio 43, 03043 Cassino, Frosinone, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,25]]},"reference":[{"key":"ref_1","first-page":"1","article-title":"Impedance control: An approach to manipulation: Part I\u2013III","volume":"107","author":"Neville","year":"1985","journal-title":"Trans. ASME J. Dyn. Syst. Meas. Control"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Wang, H., Jiang, M., Wu, L., Huang, J., Pan, Z., Li, D., Song, Y., and Huang, H. (2024). 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