Ultrafast and Robust, Resettable Threshold Sensors Based on Discontinuity-Induced Nonlinearities

阈值传感器是一种输入-输出设备，当其输入值超过阈值时，传感器会切换工作状态。这些用于监测和控制消费者和工业环境中的温度、电压、压力等临界值。工作状态的变化可能是永久性的，例如当保险丝烧坏时，或者能够被重置，例如使用断路器。本研究旨在分析、设计、制造和实验表征一类超快、鲁棒、可复位的机电阈值传感器。这里提出的基本设计原则依赖于系统响应的预测变化，特别是对分段光滑动力系统，包括碰撞和摩擦样不连续。提出的研究将验证这些理论预测，并证明在宏观和微观机电设备中使用主动反馈控制成功地调节开关率。这项研究成果对非线性动力学的新兴研究做出了原创性的贡献，它将使该领域从一个对观察行为进行建模和分析的工具转变为一个有意综合工程系统的工具。人造设备的工程表现出理想的非线性，有可能极大地拓宽应用工程师的工具箱，并以数量级改变现有应用的性能特征。目前的工作是一个基础和全面的努力，以建立所谓的非光滑折叠分岔与振动冲击系统中低速接触的开始有关，作为器件设计中可开发的非线性现象，例如，电容驱动电路保护装置。在这种分岔之后的超快响应的初步结果显示了传感器性能显着改善的巨大潜力。这项研究是与瑞典斯德哥尔摩皇家理工学院和意大利罗马拉萨皮恩扎大学的研究小组进行的国际合作，并将包括项目研究生研究助理对国际场址的几次长期访问。

Threshold sensors are input-output devices that switch operating state in reaction to the crossing of a threshold value of their input. These are used to monitor and control critical values of temperature, voltage, pressure, etc. in both consumer and industrial settings. The change in operating state might be permanent, such as when a fuse burns out, or capable of being reset, such as with a circuit breaker. This research effort aims to analyze, design, fabricate, and experimentally characterize a class of ultrafast and robust, resettable electromechanical threshold sensors. The fundamental design principle proposed here relies on predicted changes in system response particular to piecewise-smooth dynamical systems including impact- and friction-like discontinuities. The proposed research will validate these theoretical predictions and demonstrate the successful regulation of switch rates using active feedback control in macro- and microscale electromechanical devices.This research effort makes original contributions to a nascent effort in nonlinear dynamics that will transform the field from a tool for modeling and analysis of observed behavior to a tool of intentional synthesis of engineered systems. The engineering of man-made devices to exhibit desirable nonlinearities has the potential to dramatically broaden the toolbox of the applied engineer and to change the performance characteristics in existing applications by orders of magnitude. The present work is a basic and comprehensive effort to establish the so-called nonsmooth fold bifurcation associated with the onset of low-velocity contact in vibro-impacting systems as an exploitable nonlinear phenomenon in device design, e.g., capacitively-driven circuit protection devices. Preliminary results on the ultrafast response following this bifurcation show a significant potential for dramatic improvement in sensor performance.This research is an international collaboration with research groups at the Royal Institute of Technology in Stockholm, Sweden and at La Sapienza University in Rome, Italy and will include several extended visits of project graduate research assistants to the international sites.