Precise temperature control method for spacecraft under low measurement accuracy constraints

To meet the demand for precise temperature control in spacecraft under the constraint of low temperature measurement resolution, this paper proposes a high-precision temperature control method based on Kalman filtering (KF). This method first constructs a thermal model of the controlled object. The Kalman filter algorithm is then utilized to estimate temperature state changes and suppress temperature measurement noise. Finally, closed-loop control based on the filtered data is implemented to achieve high-precision temperature regulation. A modified Kalman filter (mKF) approach that incorporates continuous correction based on moving average filter results is suggested in order to address the problem of parameter adjustment inherent in this method. Through experiments and simulations, the influence of parameter settings on temperature control accuracy was analyzed. The findings demonstrate that the temperature control system using Kalman filtering improves control accuracy and adaptability to larger PI parameter values under the constraint of a temperature measurement resolution lower than 100 mK, achieving a stability better than 10 mK across a wider parameter range. After applying the modified Kalman Filtermethod, the system's temperature control accuracy under large PI control parameters is further improved. Moreover, the system exhibits lower sensitivity to PI control parameters, filtering parameters, and thermal model parameters, resulting in reduced parameter tuning difficulty and enhanced robustness.