基于微波调控的离子推力器数字反馈控制研究

Digital Feedback Control of Ion Thruster Based on Microwave Control

空间引力波探测卫星平台对微推力器提出了“快响应、低噪声、高稳定性”等多重性能指标,针对传统开环运行的推进系统难以满足高精度性能的问题,以推力估计准确度高、可控性强等主要特性的微型微波离子推力器为研究对象,采取微波调控策略,并通过模拟电路、数字控制技术相结合的精密反馈控制方法,实现了15ms快响应、10-3~1Hz频段噪声小于0.1μN/Hz1/2的推力输出指标。研究表明:与开环调节相比,反馈控制能有效抑制器件温漂及推力器复杂耦合等工作特性带来的各种噪声及扰动,且本文所采用的抗混叠滤波器方案能有效抑制数控过程中高频数据在低中频段的折叠,从而提升推力噪声指标。

Facing the multiple performance indicators of‘fast response,low noise,and high stability’pro⁃posed by the space gravitational wave detection satellite platform for the micro thruster,it is difficult to meet the high-precision performance of the traditional open-loop propulsion system.Based on the miniature microwave ion thruster with the main characteristics of high thrust estimation accuracy and strong controllability,this paper adopts the microwave control strategy,and the precise feedback control method combining analog circuit and digi⁃tal control technology to achieve 15ms fast response,10-3~1Hz frequency band noise less than 0.1μN/Hz1/2 thrust output index.The research shows that compared with open-loop regulation,feedback control can effectively sup⁃press various noises and disturbances caused by device temperature drift and complex coupling operating charac⁃teristics of thrusters,and the anti-aliasing filter scheme adopted in this paper can effectively suppress the folding of high-frequency data in the low and medium frequency bands during the digital control process, thus improvingthe thrust noise index.