sTISSUE /lab/amtl/ en Soft Robotics (2020): Miniaturized Circuitry for Capacitive Self-sensing and Closed-loop Control of Soft Electrostatic Transducers /lab/amtl/2021/01/23/soft-robotics-2020-miniaturized-circuitry-capacitive-self-sensing-and-closed-loop-control <span>Soft Robotics (2020): Miniaturized Circuitry for Capacitive Self-sensing and Closed-loop Control of Soft Electrostatic Transducers</span> <span><span>Anonymous (not verified)</span></span> <span><time datetime="2021-01-23T15:04:41-07:00" title="Saturday, January 23, 2021 - 15:04">Sat, 01/23/2021 - 15:04</time> </span> <div role="contentinfo" class="container ucb-article-tags" itemprop="keywords"> <span class="visually-hidden">Tags:</span> <div class="ucb-article-tag-icon" aria-hidden="true"> <i class="fa-solid fa-tags"></i> </div> <a href="/lab/amtl/taxonomy/term/56" hreflang="en">Soft Robotics</a> <a href="/lab/amtl/taxonomy/term/75" hreflang="en">sTISSUE</a> </div> <div class="ucb-article-content ucb-striped-content"> <div class="container"> <div class="paragraph paragraph--type--article-content paragraph--view-mode--default"> <div class="ucb-article-content-media ucb-article-content-media-above"> <div> <div class="paragraph paragraph--type--media paragraph--view-mode--default"> </div> </div> </div> <div class="ucb-article-text d-flex align-items-center" itemprop="articleBody"> <div><p>[video:https://youtu.be/fw3BwmrpdmU]</p> <p><strong>Abstract: </strong>Soft robotics is a field of robotic system design characterized by materials and structures that exhibit large-scale deformation, high compliance, and rich multifunctionality. The incorporation of soft and deformable structures endows soft robotic systems with the compliance and resiliency that makes them well adapted for unstructured and dynamic environments. Although actuation mechanisms for soft robots vary widely, soft electrostatic transducers such as dielectric elastomer actuators (DEAs) and hydraulically amplified self-healing electrostatic (HASEL) actuators have demonstrated promise due to their muscle-like performance and capacitive self-sensing capabilities. Despite previous efforts to implement self-sensing in electrostatic transducers by overlaying sinusoidal low-voltage signals, these designs still require sensing high-voltage signals, requiring bulky components that prevent integration with miniature untethered soft robots. We present a circuit design that eliminates the need for any high-voltage sensing components, thereby facilitating the design of simple low cost circuits using off-the-shelf components. Using this circuit, we perform simultaneous sensing and actuation for a range of electrostatic transducers including circular DEAs and HASEL actuators and demonstrate accurate estimated displacements with errors &lt;4%. We further develop this circuit into a compact and portable system that couples high voltage actuation, sensing, and computation as a prototype toward untethered multifunctional soft robotic systems. Finally, we demonstrate the capabilities of our self-sensing design through feedback control of a robotic arm powered by Peano-HASEL actuators..</p> <p><strong>Ly, K., Kellaris, N., McMorris, D., Johnson, B.K., Acome, E., Sundaram, V., Naris, M., Humbert, J.S., Rentschler, M.E., Keplinger, C., Correll, N., “Miniaturized Circuitry for Capacitive Self-sensing and Closed-loop Control of Soft Electrostatic Transducers,” <em>Soft Robotics.</em></strong></p> <p><strong>(<a href="https://doi.org/10.1089/soro.2020.0048" rel="nofollow">Downloadable PDF</a>)</strong></p></div> </div> </div> </div> </div> <h2> <div class="paragraph paragraph--type--ucb-related-articles-block paragraph--view-mode--default"> <div>Off</div> </div> </h2> <div>Traditional</div> <div>0</div> <div>On</div> <div>White</div> Sat, 23 Jan 2021 22:04:41 +0000 Anonymous 469 at /lab/amtl IEEE International Conference on Soft Robotics (RoboSoft) (2020): Identification and Control of a Nonlinear Soft Actuator and Sensor System /lab/amtl/2020/08/23/ieee-international-conference-soft-robotics-robosoft-2020-identification-and-control <span>IEEE International Conference on Soft Robotics (RoboSoft) (2020): Identification and Control of a Nonlinear Soft Actuator and Sensor System</span> <span><span>Anonymous (not verified)</span></span> <span><time datetime="2020-08-23T13:55:16-06:00" title="Sunday, August 23, 2020 - 13:55">Sun, 08/23/2020 - 13:55</time> </span> <div role="contentinfo" class="container ucb-article-tags" itemprop="keywords"> <span class="visually-hidden">Tags:</span> <div class="ucb-article-tag-icon" aria-hidden="true"> <i class="fa-solid fa-tags"></i> </div> <a href="/lab/amtl/taxonomy/term/56" hreflang="en">Soft Robotics</a> <a href="/lab/amtl/taxonomy/term/75" hreflang="en">sTISSUE</a> </div> <div class="ucb-article-content ucb-striped-content"> <div class="container"> <div class="paragraph paragraph--type--article-content paragraph--view-mode--default"> <div class="ucb-article-content-media ucb-article-content-media-above"> <div> <div class="paragraph paragraph--type--media paragraph--view-mode--default"> </div> </div> </div> <div class="ucb-article-text d-flex align-items-center" itemprop="articleBody"> <div><p>[video: https://youtu.be/EcBuuulZMjY]</p> <p><strong>Abstract: </strong>Soft robots are becoming increasingly prevalent, with unique applications to medical devices and wearable technology. Understanding the dynamics of nonlinear soft actuators is crucial to creating controllable soft robots. this letter presents a system identification process and closed-loop control of foldable HASEL (hydraulically amplified self-healing electrostatic) soft actuators. We characterized foldable HASELs with linear frequency response tests and modeled them using a linear superposition of static and dynamic terms. We also identified two responses of the system: an activation and relaxation response. Based on these two responses, we developed a dual-mode controller which was validated through closed-loop control using a capacitive elastomeric strain sensor wrapped around the actuator. Using this integrated sensor, we achieved step response rise times as fast as 0.025 s and settling times as fast as 0.17 s while under load. These system identification and control techniques can be applied to any HASEL-driven soft robot and could be applied to other soft actuators to enable controllable soft robots.</p> <p><strong>Johnson, B.K., Sundaram, V., Naris, M., Acome, E., Ly, K., Correll, N., Keplinger, C.M., Humbert, J.S., Rentschler, M.E., “<em>Identification and Control of a Nonlinear Soft Actuator and Sensor System</em>,” IEEE International Conference on Soft Robotics (RoboSoft), Yale University, April, 2020.</strong></p> <p><strong>(<a href="https://doi.org/10.1109/LRA.2020.2982056" rel="nofollow">Downloadable PDF</a>)</strong></p></div> </div> </div> </div> </div> <h2> <div class="paragraph paragraph--type--ucb-related-articles-block paragraph--view-mode--default"> <div>Off</div> </div> </h2> <div>Traditional</div> <div>0</div> <div>On</div> <div>White</div> Sun, 23 Aug 2020 19:55:16 +0000 Anonymous 455 at /lab/amtl IEEE Robotics and Automation Letters (2020): Identification and Control of a Nonlinear Soft Actuator and Sensor System /lab/amtl/2020/08/23/ieee-robotics-and-automation-letters-2020-identification-and-control-nonlinear-soft <span>IEEE Robotics and Automation Letters (2020): Identification and Control of a Nonlinear Soft Actuator and Sensor System</span> <span><span>Anonymous (not verified)</span></span> <span><time datetime="2020-08-23T13:40:03-06:00" title="Sunday, August 23, 2020 - 13:40">Sun, 08/23/2020 - 13:40</time> </span> <div role="contentinfo" class="container ucb-article-tags" itemprop="keywords"> <span class="visually-hidden">Tags:</span> <div class="ucb-article-tag-icon" aria-hidden="true"> <i class="fa-solid fa-tags"></i> </div> <a href="/lab/amtl/taxonomy/term/56" hreflang="en">Soft Robotics</a> <a href="/lab/amtl/taxonomy/term/75" hreflang="en">sTISSUE</a> </div> <div class="ucb-article-content ucb-striped-content"> <div class="container"> <div class="paragraph paragraph--type--article-content paragraph--view-mode--default"> <div class="ucb-article-content-media ucb-article-content-media-above"> <div> <div class="paragraph paragraph--type--media paragraph--view-mode--default"> </div> </div> </div> <div class="ucb-article-text d-flex align-items-center" itemprop="articleBody"> <div><p>[video:https://youtu.be/gXO46FtMJp4]</p> <p><strong>Abstract: </strong>Soft robots are becoming increasingly prevalent, with unique applications to medical devices and wearable technology. Understanding the dynamics of nonlinear soft actuators is crucial to creating controllable soft robots. this letter presents a system identification process and closed-loop control of foldable HASEL (hydraulically amplified self-healing electrostatic) soft actuators. We characterized foldable HASELs with linear frequency response tests and modeled them using a linear superposition of static and dynamic terms. We also identified two responses of the system: an activation and relaxation response. Based on these two responses, we developed a dual-mode controller which was validated through closed-loop control using a capacitive elastomeric strain sensor wrapped around the actuator. Using this integrated sensor, we achieved step response rise times as fast as 0.025 s and settling times as fast as 0.17 s while under load. These system identification and control techniques can be applied to any HASEL-driven soft robot and could be applied to other soft actuators to enable controllable soft robots.</p> <p><strong>Johnson, B.K., Sundaram, V., Naris, M., Acome, E., Ly, K., Correll, N., Keplinger, C.M., Humbert, J.S., Rentschler, M.E., “Identification and Control of a Nonlinear Soft Actuator and Sensor System,” <em>IEEE Robotics and Automation Letters</em>. 5(3): 3783-3790, 2020.</strong></p> <p><strong>(<a href="https://doi.org/10.1109/LRA.2020.2982056" rel="nofollow">Downloadable PDF</a>)</strong></p></div> </div> </div> </div> </div> <h2> <div class="paragraph paragraph--type--ucb-related-articles-block paragraph--view-mode--default"> <div>Off</div> </div> </h2> <div>Traditional</div> <div>0</div> <div>On</div> <div>White</div> Sun, 23 Aug 2020 19:40:03 +0000 Anonymous 451 at /lab/amtl