scholarly journals Use of the Method of Guidance by a Required Velocity in Control of Spacecraft Attitude

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Mikhail Valer’evich Levskii

We apply the method of guidance by a required velocity for solving theoptimal control problem over spacecraft’s reorientation from known initialattitude into a required final attitude. We suppose that attitude control iscarried out by impulse jet engines. For optimization of fuel consumption,the controlling moments are calculated and formed according to themethod of free trajectories together with principle of iterative controlusing the quaternions for generating commands to actuators. Optimalsolution corresponds to the principle “acceleration - free rotation - separatecorrections - free rotation - braking”. Rotation along a hitting trajectory issupported by insignificant correction of the uncontrolled motion at discreteinstants between segments of acceleration and braking. Various strategies在自由运动阶段形成校正脉冲的方法是建议。提高实现航天器最终位置的准确性通过终端控制使用有关当前姿态的信息和用于确定开始时刻的角速度测量制动(根据实际运动参数开始制动的条件以分析形式制定)。所描述的方法是通用的并且相对于转动惯量不变。发展的态度法则控制涉及具有预测模型的算法,综合控制模式对于外部扰动和参数错误。数学建模的结果表明证明设计算法的实际可行性和高效率。

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengxi Zhang ◽  
Hui-Jie Sun ◽  
Jin Wu ◽  
Zhongyang Fei ◽  
Yu Jiang ◽  
...  

Purpose This paper aims to study the attitude control problem with mutating orbital rate and actuator fading. Design/methodology/approach To avoid malicious physical attacks and hide itself, the spacecraft may irregularly switch its orbit altitude within a specific range, which will bring about variations in orbital rate, thereby causing mutations in the attitude dynamics model. The actuator faults will also cause changes in system dynamics. Both factors affect the control performance. First, this paper determines the potential switching orbits. Then under different conditions, design controllers that can accommodate actuator faults according to the statistical law of actuator fading. Findings This paper, to the best of the authors’ knowledge, for the first time, introduces the Markovian jump framework to model the possible unexpected mutating of orbital rate and actuator fading of spacecraft and then designs a novel control policy to solve the attitude control problem. Practical implications This paper also provides the algorithm design processes in detail. A comparative numerical simulation is given to verify the effectiveness of the proposed algorithm. Originality/value This is an early solution for spacecraft attitude control with dynamics model mutations.


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