{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T05:09:09Z","timestamp":1783573749483,"version":"3.55.0"},"reference-count":26,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,6,23]],"date-time":"2025-06-23T00:00:00Z","timestamp":1750636800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The integration of robots into collaborative environments, where they physically interact with humans, requires systems capable of ensuring both safety and performance. This work introduces the development of a Variable Stiffness Impact Testing Device (VSITD), designed to emulate physical human\u2013robot interaction by replicating biomechanical properties such as muscle elasticity and joint compliance. The proposed system integrates a Variable Stiffness Mechanism (VSM) with a multi-sensor configuration that includes a high-resolution Force Sensitive Resistors (FSR) matrix, piezoelectric load cells, and an FPGA-based acquisition unit. The FPGA enables fast acquisition of contact forces and pressures, while the mechanical stiffness configuration of the VSM can be rapidly reconfigured to simulate a wide range of impact scenarios. The device aims to validate compliance with the standard ISO\/TS 15066 safety standard of robotic work cell in the context of collaborative application. The modularity and flexibility of the VSITD make it suitable for evaluating a wide range of collaborative robotic platforms, providing a reliable tool for pre-deployment validation in shared workspaces. By combining real-time sensing with adaptable stiffness control, the VSITD establishes a new benchmark for safety testing in human\u2013robot collaboration scenarios.<\/jats:p>","DOI":"10.3390\/s25133913","type":"journal-article","created":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T04:37:21Z","timestamp":1750739841000},"page":"3913","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["A Variable Stiffness System for Impact Analysis in Collaborative Robotics Applications with FPGA-Based Force and Pressure Data Acquisition"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-0669-0380","authenticated-orcid":false,"given":"Andrea","family":"D\u2019Antona","sequence":"first","affiliation":[{"name":"Department of Engineering, University of Ferrara, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3480-1351","authenticated-orcid":false,"given":"Saverio","family":"Farsoni","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Ferrara, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-4544-298X","authenticated-orcid":false,"given":"Jacopo","family":"Rizzi","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Ferrara, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6065-9769","authenticated-orcid":false,"given":"Marcello","family":"Bonf\u00e8","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Ferrara, 44121 Ferrara, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.jsv.2015.10.024","article-title":"A wide-range variable stiffness mechanism for semi-active vibration systems","volume":"363","author":"Wu","year":"2016","journal-title":"J. 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