PECASE: Analysis and Design of Discontinuity-Driven Bifurcations

提案标题：PECASE：不连续驱动分岔的分析和设计机构：弗吉尼亚理工学院和州立大学该奖项侧重于非光滑动力系统的分析和设计，其特征是系统属性的突然和不连续变化，通常在机械，生物和电子模型中遇到。特别重要的是潜在的戏剧性的变化，在与环境的弱相互作用的开始，这里被称为不连续驱动的分叉发生在这样的系统的运动的性质和稳定性。例如，在人类步态的情况下，摆动脚的过早的低速地面接触可能导致持续步态的稳定性丧失和随后的跌倒，特别是在患有肌肉疾病的个体或老年人中。该项目的目标是为周期性和瞬时运动的不连续驱动分叉开发一种全面的预测方法，并制定设计标准，以减少或消除机械子系统及其周围环境之间无意碰撞的有害影响-特别是预防步态期间过早接触地面造成的跌倒相关伤害。该研究工作将与开发初级封闭式设计课程紧密结合，该课程强调机电一体化系统的性能验证测试以及在存在平滑和不连续驱动分叉的情况下对系统响应的评估。该项目最初是作为CAREER奖资助的，并于2004年9月转换为总统工程师和科学家早期职业奖（PECASE）。

Proposal Title: PECASE: Analysis and Design of Discontinuity-Driven BifurcationsInstitution: Virginia Polytechnic Institute and State UniversityThis award focuses on the analysis and design of nonsmooth dynamical systems, characterized by abrupt and discontinuous changes in the systems' properties, and commonly encountered in mechanical, biological, and electronic models. Of particular significance are the potentially dramatic changes in character and stability of motions of such systems that occur at the onset of weak interactions with the environment, here referred to as discontinuity-driven bifurcations. For example, in the case of human gait, premature, low-velocity ground contact of the swing foot may result in loss of stability of the sustained gait and subsequent fall, particularly in individuals with muscular disorders or the elderly. The objectives of this project are to develop a comprehensive predictive methodology for discontinuity-driven bifurcations of recurrent and transient motions and to formulate design criteria for reducing or eliminating the detrimental effects of unintentional collisions between a mechanical subsystem and its surrounding environment -- in particular, the prevention of fall-related injury due to premature ground contact during gait. The research work will closely integrate with an effort to develop a closed-ended-design course at the junior level emphasizing performance verification tests for mechatronic systems and the evaluation of a system's response in the presence of smooth and discontinuity-driven bifurcations.This project was originally funded as a CAREER award, and was converted to a Presidential Early Career Award for Engineers and Scientists (PECASE) award in September 2004.