Real-time state estimation of low-frequency plasma oscillations in Hall effect thrusters

An extended Kalman filter (EKF) is developed to estimate unobserved states and parameters in plasma dynamical systems. Physical constraints are satisfied by adapting the process and measurement noise covariances to account for consistency between the estimates and the physical processes. First, the EKF is tested using the Lorenz system to demonstrate the robustness of the EKF with sparse measurement data. Then, the capabilities of the EKF are applied to investigate discharge current oscillations in a Hall effect thruster. It is demonstrated that the dynamics of the electron temperature can be estimated using the discharge current fluctuation as the measurement data. The propagation of the uncertainties of such estimates is also quantified. Published under an exclusive license by AIP Publishing.

Automated summary

An extended Kalman filter is developed for estimating unobserved states and parameters in plasma dynamical systems, ensuring consistency between estimates and physical processes by adjusting noise covariances. The EKF demonstrates robustness with sparse measurement data and is successfully applied to investigate discharge current oscillations. It shows that electron temperature dynamics can be estimated using discharge current fluctuation as measurement data, with quantified uncertainties in the estimates.