离子推力器栅极组件热变形测量方法

栅极组件是离子推力器的核心部件，其所包含的多层栅极结构在工作过程中会发生热变形，导致栅极间距发生改变，进而影响离子推力器的工作性能及寿命。为了实现栅极结构在实际工况下热变形的非接触测量与评估，本研究提出了基于摄像测量的栅极变形观测方法，评价了不同图像分析方法（灰度重心法、圆拟合法、灰度匹配法）对变形测量精度的影响。结果表明灰度匹配方法观测精度高，环境适应性好；同时，设计并实现了一套栅极热变形环境模拟与变形测量系统，可实现高温、通水、通气环境下变形的高精度观测。最后，对环境箱通水通气对测量精度的影响进行了评价，结果表明二者均会对测量精度造成影响，通水对实验结果的影响大于通气的影响。

Research on Thermal Deformation Measurement Method of Ion Thruster Grid Assembly

The grid assembly is the core component of the ion thruster. And the multilayer grid structure it contains will undergo thermal deformation during the working process, resulting in the changes of the grid spacing, and then affecting the working performance and life of the ion thruster. In order to realize the non-contact measurement and evaluation of thermal deformation of grid structure under real working conditions, an observation method of grid deformation based on camera measurement is proposed which enables to evaluate the effects of different image analysis methods (grayscale center of gravity, circle fitting, and grayscale matching) on the accuracy of deformation measurement. The results show that the grayscale matching method has high observation accuracy and good environmental adaptability. Additionally, a set of grid thermal deformation environment simulation and deformation measurement system is designed and implemented, which can realize high-precision observation of deformation under conditions of high temperature, water circulation and air circulation. Finally, the effects on the accuracy of deformation measurement under the conditions of water circulation and air circulation in the environmental chamber are evaluated, and the results indicate that both of the two conditions affect the measurement accuracy, and the effect of water circulation on the experimental results is more significant than that air circulation.