System and Control Analysis of Low Pressure Plasma Deposition

基于系统的方法将用于改进低压等离子沉积(LPPD)工艺。LPPD可以生产出微观结构细小、密度高、具有实用工程形状的工程材料。重要的应用包括生产用于燃气轮机和飞机发动机的金属基复合材料和合金材料。目前，这些过程是以经验确定的前馈方式运行的。这对可实现的材料质量和工艺适应新的制造和材料要求的速度造成了限制。这项研究将确定开发替代控制器设计所需的重要过程特性，并将有助于优化操作制度和系统设计。将开发低阶模型(LOM)来捕捉主导系统动力学，以揭示重要的系统关系。过程模型将被分析以获得对LPPD的过程约束的明确描述。LOM将由过程物理的集总和参数表示并通过简化现有的高阶模型来开发。分析结果将通过与现有高阶模型和实验研究的比较得到证实。

A systems based approach will be used for improving low pressure plasma deposition (LPPD) processes. LPPD enables production of engineering materials of fine microstructure, high density, in useful engineering shapes. Important applications include production of metal matrix composites and alloy materials used in gas turbines and aircraft engines. Currently, these processes are operated in an empirically determined feedforward fashion. This poses limits on the achievable material quality and on the speed the process can be adapted to meet new manufacturing and materials requirements. This study will determine the important process characteristics needed to develop alternative controller design and will also aid in optimizing the operating regime and system design. Low order models (LOMs) that capture the dominant system dynamics will be developed to reveal the important system relationships. The process models will be analyzed to obtain an explicit description of the process constraints for LPPD.The LOMs will be developed from lumped and parametric representations of the process physics and by reduction of existing high order models. Analysis results will be confirmed by comparison to existing high order modelling and experimental studies.