INVESTIGATION OF THE ALGORITHM OF DIFFERENTIAL CORRECTION WITH LIMITED THRUST DURING PHASE MODULATION CONTROL OF THE ORBIT OF SPACECRAFT

CHen Long

Introduction. The article examines the problem of optimizing the algorithm for differential correction of orbits of spacecraft with limited thrust under phase modulation control. The aim of the work is to develop an improved method for correcting the spacecraft's orbit, which ensures an increase in the accuracy of launching into the target orbit while minimizing energy consumption. To achieve this goal, tasks are solved: 1) modeling the dynamics of spacecraft motion taking into account disturbing factors; 2) synthesis of the optimal law of phase-modulating thrust control; 3) analysis of convergence and stability of the proposed algorithm. Methods. The apparatus of the theory of optimal control, methods of mathematical modeling, analytical design of regulators, as well as numerical methods for calculating trajectories are used. The empirical basis is the full-scale measurements of the parameters of the orbits of several spacecraft, which were corrected according to the standard method. The characteristics of disturbing influences are generated based on statistical models of the upper atmosphere. Results. A new differential correction algorithm has been developed that combines the principles of phase modulation control and optimization of the consumption of the working fluid of low-thrust engines. A comparison of the dynamic and accuracy characteristics of the proposed and traditional algorithms in various conditions is carried out. The asymptotic stability of the synthesized control law under variations of the orbit parameters and thrust limitations is proved. Discussion. The results obtained are of practical value for improving the efficiency of orbit correction of existing and prospective spacecraft. The developed approach can be extended to a class of adaptive correction algorithms with real-time identification of motion parameters. It is advisable to direct further research to optimize the procedures for calculating control actions in the spacecraft's on-board computer.

Keywords:spacecraft, orbit correction, phase modulation control, differential algorithm, limited thrust, optimization, stability