CAREER: Structure and Robustness in Nonlinear Control: Challenges from Fuel Cell Technology

本提案的研究目标是开发系统设计工具，利用而不是覆盖反馈系统中的非线性和结构特性。受我们初步结果的鼓舞，我们解决了观测器设计和对未建模动力学的鲁棒性问题，这对于非线性控制技术的实际适用性至关重要。非线性系统中动态现象的多样性阻碍了这些问题的建设性解决。相反，我们追求针对固有系统特性和非线性现象量身定制的结构特定设计。我们强大的设计工具利用各种未建模的动力学和多变量结构来恢复标称设计可实现的稳定性和性能。我们的观测器利用非线性来增强观测器的收敛性，并在确定性等价实现中恢复全状态反馈设计的稳定性。PI将与联合技术研究中心合作，将这些设计工具应用于燃料电池动力系统中出现的反馈问题。燃料电池技术特别适合美国，因为广阔的地理位置使得集中式电网容易出现故障，而严格的环境法规强调了清洁发电的必要性。潜在的车载和便携式电源应用面临的主要挑战是高阶、互联的系统结构和严重的非线性，这些非线性是由系统组件的紧密集成和电力负荷的广泛变化引起的。对未建模动力学的鲁棒性对低阶设计的可靠性至关重要。非线性观测器非常重要，因为商业上可用的传感器技术不是设计用于在燃料电池环境中运行的。燃料电池的研究将为抽象和广泛的设计方法奠定基础，这也将影响其他技术，如计算机网络、化学过程和航空发动机的流体控制问题，在这些技术中，高阶系统模型和严重的非线性构成了高效可靠反馈设计的障碍。该提案的教育目标是使更广泛的学生能够理解非线性概念。PI将为希望在入门阶段学习非线性系统的本科生和研究生引入一门新课程。本课程将提高未来实践者对非线性系统的认识，并吸引更多学生参加我们的研究生研究计划。与当地学区和伦斯勒理工学院的新愿景计划合作，我们将把高中生与本科生一起纳入项目组。几个教学实验和电脑动画，在提案中详细说明，将给他们一个激励的现实生活中接触动态现象和控制概念。

The research objective of this proposal is to develop systematic design tools that exploit, ratherthan override, nonlinearities and structural properties in feedback systems. Encouraged by ourpreliminary results, we address the problems of observer design and robustness to unmodeleddynamics, which are crucial for practical applicability of nonlinear control techniques. The variety ofdynamic phenomena in nonlinear systems have hampered constructive solutions to these problems.In contrast, we pursue structure-specific designs which are tailored to inherent system propertiesand nonlinear phenomena. Our robust design tools exploit types of unmodeled dynamics andmultivariable structures to recover stability and performance achievable with nominal designs. Ourobservers take advantage of nonlinearities to enhance observer convergence and to recover stabilityof full state-feedback designs in certainty-equivalence implementations.In collaboration with United Technologies Research Center, the PI will apply these design toolsto emerging feedback problems in fuel cell power systems. Fuel cell technology is particularly suit-able for United States, because the wide geography makes centralized power networks prone tofailure, and the strict environmental regulations accentuate the necessity of clean power genera-tion.A major challenge for potential vehicular and portable power applications is the high-order,interconnected, system structure, and severe nonlinearities, which arise from tight integration ofsystem components and wide variations in the electric load. Robustness to unmodeled dynamicsis crucial for reliability of low-order designs. Nonlinear observers are of great importance becausecommercially available sensor technologies are not designed to operate in a fuel cell environment.The study of fuel cells will set the stage for abstractions and broad design methodologies which willalso impact other technologies, such as computer networks, chemical processes, and fluid controlproblems in aeroengines, where high-order system models and severe nonlinearities constitute anobstacle to efficient and reliable feedback designs.The educational objective of the proposal is to make nonlinear concepts accessible to a widerspectrum of students. The PI will introduce a new course for undergraduates, and graduate stu-dents who wish to study nonlinear systems at an introductory level. This course will enhance theappreciation of nonlinear systems among practitioners of the future, and attract more studentsto our graduate research program. In collaboration with the New Visions Program of local schooldistricts and Rensselaer Polytechnic Institute, we will include high-school students in project teamswith our undergraduates. Several pedagogical experiments and computer animations, detailed inthe proposal, will give them a motivating real-life exposure to dynamic phenomena and controlconcepts.