SGER: A Control-Oriented Model for Ionic Polymer-Metal Composite Actuators

离子聚合物-金属复合材料（IPMCs），非正式地称为人造肌肉，是一类创新的智能材料，可以在低驱动电压下产生大的弯曲运动。作为实现IPMC全部潜力的第一步，提出的研究旨在为IPMC执行器开发一个面向控制的模型，该模型可以捕获基本的动力学和非线性。它解决了一个在现有的IPMC建模工作中很大程度上未被探索的实际问题，它通常处理复杂的连续体模型（对实时控制不可行）或简化的线性模型（仅在有限的驱动范围内有效）。该项目将探索一种新的模型结构，该结构可以解释主要的驱动机制，并包含两个非线性模块，应力-应变滞后和电行为对IPMC弯曲曲率的非线性依赖。考虑到单个模块的明确物理解释，模型识别将通过利用能量域和时间尺度的分离来执行。该模型集成了核心非线性，为IPMC执行器的快速、精确和节能控制提供了基础。作为人造肌肉，ipmc在生物医学设备、仿生机器人以及微纳米操作系统中具有广泛的潜在应用。这些应用的一个关键障碍是ipmc的复杂，非线性，机电行为。通过以一种简洁而充分的方式捕捉关键特征，拟议的研究将有助于为这些人造肌肉启用的机器人、设备和系统设计有效的控制器（“大脑”）。这可能导致敏捷假肢装置，主动生物仪器工具（例如，可操纵导管）和灵巧的微纳米操纵器，对医疗保健和微/纳米制造具有潜在影响。在这个项目中，PI还将为K-12学生举办吸引人的“行动中的人造肌肉”演示和讲座，激发年轻学生，特别是女学生对科学和工程的兴趣。

Ionic Polymer-Metal Composites (IPMCs), informally known as artificial muscles, are an innovative class of smart materials that generate large bending motions under low actuation voltages. As a first step towards the realization of the full potential of IPMCs, the proposed research aims to develop a control-oriented model for IPMC actuators that captures essential dynamics and nonlinearities. It addresses a problem of practical interest that is largely unexplored in existing IPMC modeling work, which typically deals with either complex continuum models (infeasible for real-time control) or simplified linear models (valid only within limited actuation ranges). This project will explore a novel model structure that accounts for major actuation mechanisms and incorporates two nonlinear modules, stress-strain hysteresis and nonlinear dependence of the electrical behavior on the IPMC bending curvature. Given the explicit physical interpretations of individual modules, model identification will be performed by exploiting the separation of energy domains and time scales. Integrating the core nonlinearities, the proposed model is expected to provide a basis for fast, precision, and energy-efficient control of IPMC actuators. As artificial muscles, IPMCs have a wide spectrum of potential applications in biomedical devices, biomimetic robotics, and micro- and nanomanipulation systems. One crucial barrier to these applications is the complicated, nonlinear, electromechanical behaviors of IPMCs. By capturing the key characteristics in a succinct yet adequate way, the proposed research will facilitate the design of effective controllers ("brains") for robots, devices, and systems enabled by these artificial muscles. This can lead to agile prosthetic devices, active bioinstrumentation tools (for example, steerable catheters), and dexterous micro- and nanomanipulators, with potential impacts on health care and micro/nano-manufacturing. In this project the PI will also hold appealing "artificial muscles in action" demos and lectures for K-12 students, and inspire the interest of young students, especially female students, in science and engineering.