Multi-rate Nonlinear Observers for Process Monitoring, with Application to Polymerization Reactors

通常，与安全、产品质量和/或化学过程的经济性能相关的临界量不能在线测量。然而，其他物理变量的在线测量总是可用的，并且这些测量必须用于估计和监测未测量的临界量。在这个项目中，一个动态模型，加上来自所有在线测量的附加适当的反馈项，将被用来建立一个状态观测器来估计系统的状态，由此可以估计和监控所有相关的临界量。该项目旨在通过提供统一框架中的通用算法工具以及将其应用于化工过程的实用指南来改变当前的工业实践。该研究旨在(A)促进非线性观测器的理论和(B)使先进的非线性观测器能够并扩大其在包括聚合反应器在内的化工过程的基于模型的监测中的适用性。该项目的第一个目标是开发用于过程监测的多速率、多延迟、非线性状态观测器设计的系统一般方法。实现这一目标将涉及理论研究的努力，以推动非线性系统理论的方法和成果。第二个目标涉及测试和评估理论算法框架在化学过程监控应用中的实际适用性。特别是，聚合反应的监测将是主要的应用领域。为了达到这一目标，将通过应用拟议项目理论部分的通用算法进行建模、仿真和观测器设计，以及实验实现和测试。这项研究希望对非线性观测器的理论和算法有所帮助，包括(A)多速率测量的正确处理和(B)非线性观测器设计中的多延迟测量的正确处理。它还旨在通过支持和提高所有可用在线测量的利用率，促进在化学过程操作中监测产品质量的非线性观测器的实际应用，包括聚合反应器监测。这项工作的成果将通过在科学会议上的陈述、学术参考的期刊出版物和该项目的专门网站向学术界和工业界的研究人员广泛传播。除了研究生，私人投资机构还计划招收人数不足的本科生到他们的实验室进行研究。

Very often, critical quantities related to safety, product quality and/or economic performance of a chemical process cannot be measured on line. However, on-line measurements of other physical variables are always available, and these must be used to estimate and monitor unmeasured critical quantities. In this project, a dynamic model, with additional appropriate feedback terms from all the on-line measurements, will be used to build a state observer to estimate the state of the system, from which all pertinent critical quantities can be estimated and monitored. The project aims at transforming current industrial practice on process monitoring, by providing general algorithmic tools in a unified framework, as well as practical guidelines for their application to chemical processes.The research aims at (a) advancing the theory of nonlinear observers and (b) enabling and expanding the applicability of advanced nonlinear observers for model based monitoring of chemical processes, including polymerization reactors. The first objective of the project is the development of as systematic general methodology for the design of multi-rate multi-delay nonlinear state observers for process monitoring. Meeting this objective will involve theoretical research efforts, to advance methods and results of nonlinear systems theory. The second objective involves testing and evaluation of the practical applicability of the theoretical algorithmic framework to chemical process monitoring applications. In particular, monitoring of polymerization reactions will be the principal application area. Meeting this objective will involve modeling, simulation and observer design by applying the general algorithms of the theory part of the proposed project, as well as experimental implementation and testing. The research hopes to advance the theory and algorithms of nonlinear observers, including (a) the proper handling of multi-rate measurements and (b) the proper handling of multi-delay measurements in nonlinear observer design. It also aims at advancing the practical application of nonlinear observers for monitoring product quality in the operation of chemical processes, including polymerization reactor monitoring, by enabling and improving the utilization of all available on-line measurements. The results of the work will be broadly disseminated to researchers in academia and industry through presentations at scientific conferences, scholarly refereed journal publications and through a dedicated web site for the project. In addition to graduate students, the PIs plan to recruit underrepresented undergraduate students to pursue research in their laboratories.