Institute of Systems Science and Technology, School of Electrical Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
Center for Control Theory and Guidance Technology, Harbin Institute of Technology, Harbin, 150001, China.
ISA Trans. 2019 Nov;94:17-27. doi: 10.1016/j.isatra.2019.03.031. Epub 2019 Apr 8.
Without the line-of-sight (LOS) angles rate information, this paper investigates the LOS angles tracking problem of non-cooperative target in chaser's body frame with the external disturbance force and torque via chaser's control torque. By integrating with the attitude dynamics of the chaser, a novel coupled LOS-based relative motion model is firstly established, which reveals the redundancy relationship between the LOS angles motion with two Degree-of-Freedom (DOF) and three dimensional control torque. More specially, the LOS angles tracking control problem is formulated as an output-feedback control problem of an uncertain nonlinear system with the actuator redundancy. As a stepping-stone, a fourth order high order sliding mode observer (HOSMO) is proposed to estimate the system state and uncertain terms. A combination of modified super twisting algorithm (STA) with nonsingular fast terminal sliding mode (NFTSM) and control allocation is proposed, the main novelty of modified STA is that the NFTSM is introduced to replace the linear sliding mode (LSM), and the original STA cannot be applied directly, a modified STA is proposed, which can guarantee the fast finite-time convergence. Finally, simulations are conducted to show fine performance of the proposed control scheme.
在没有视线（LoS）角度速率信息的情况下，本文通过追踪器的控制扭矩，研究了外部干扰力和扭矩作用下追踪器体坐标系中非合作目标的LoS 角度跟踪问题。通过与追踪器的姿态动力学相结合，首先建立了一种新颖的基于 LOS 的相对运动模型，该模型揭示了 LOS 角度运动与二维自由度（DOF）和三维控制扭矩之间的冗余关系。更特别的是，LoS 角度跟踪控制问题被表述为具有执行器冗余的不确定非线性系统的输出反馈控制问题。作为一个垫脚石，提出了四阶高阶滑模观测器（HOSMO）来估计系统状态和不确定项。提出了一种改进的超扭曲算法（STA）与非奇异快速终端滑模（NFTSM）和控制分配的组合，改进 STA 的主要新颖之处在于引入了 NFTSM 来代替线性滑模（LSM），而原始 STA 不能直接应用，提出了一种改进的 STA，可以保证快速有限时间收敛。最后，进行了仿真以显示所提出的控制方案的良好性能。
