考虑输入饱和的航天器相对运动鲁棒自适应控制

 研究了在输入饱和约束条件下的航天器相对运动的姿态和轨道一体化控制问题。首先,基于单位对偶四元数给出了航天器6自由度相对运动的数学模型,利用误差对偶四元数来描述航天器的相对姿态和相对位置。接着,针对输入饱和问题,提出了一种对航天器模型参数不确定性和外部有界干扰具有较强鲁棒性的自适应控制器,并通过李雅普诺夫方法从理论上严格证明了整个闭环系统的全局渐近稳定性。最后,通过数值仿真来验证设计方法的有效性和可行性,并且与其他方法进行了比较,结果表明设计的方法能够抑制输入饱和的问题,在性能上具有更快的收敛速度和更强的鲁棒性。

Robust Adaptive Control for Relative Motion of Spacecraft Under Input Saturation

This paper investigates the integrated control of attitude and orbit for the relative motion of a spacecraft in the presence of input saturation constraint. First, using unit dual quaternion, a mathematic model of the six-degree-of-freedom relative motion for the spacecraft is introduced, and an error dual quaternion is adopted to describe the relative attitude and position of the spacecraft. Second, an adaptive controller, which is robust enough to model the uncertainties of the spacecraft and its bounded external disturbances, is proposed to deal with input saturation. Moreover, it is proved by a rigorous theoretical analysis of the Lyapunov method that the whole resulting closed-loop system is globally and asymptotically stable. Finally, numerical simulations are performed to demonstrate the validity and effectiveness of the presented approach. Compared with other approaches, the new one has the following properties: 1) control input saturation can be explicitly restrained; 2) faster convergence rate and improved robustness can be obtained.