Harbin Institute of Technology, Shen Zhen 518055, China.
National key laboratory of science and technology on test physics and numerical mathematics, Beijing 100076, China.
ISA Trans. 2023 Jul;138:133-150. doi: 10.1016/j.isatra.2023.02.022. Epub 2023 Feb 20.
The quantized control problem for a heavy-lift launch vehicle (HLV) under actuator faults and rate gyro malfunctions is addressed in this paper. A predefined-time observer (PTO) is designed to reconstruct the immeasurable time derivative of attitude tracking errors with the settling time precisely predefined by one design parameter. Thus, parameter tuning for temporal demands is more straightforward and less conservative for the PTO than for fixed-time observers. Using the reconstructed state, a quantized controller is developed to render attitude tracking errors to a small neighborhood of the origin within a predefined time interval (physically realizable) under actuator faults. The controller has three characteristics (1) An unswitched singularity-avoidance layer is derived to ensure the boundedness of control signals. (2) A hysteresis quantizer is used to discretize control signals for applications on the digital onboard platform and reduce communication burden. (3) The settling time of attitude tracking errors is predefined by two design parameters under discretized control signals without using performance functions, avoiding the risks of violating performance functions and sudden controller collapse suffered by the existing quantized predefined-time controllers. Furthermore, stability analysis is impelled using a nonsmooth analysis method and a Lyapunov method. Finally, numerical simulations on an HLV demonstrate the efficiency of the proposed control system.
本文研究了执行器故障和速率陀螺故障下重载运载火箭（HLV）的量化控制问题。设计了一个预设时间观测器（PTO），以在所设定的一个设计参数下精确预设的调整时间来重建姿态跟踪误差的不可测量时间导数。因此，与固定时间观测器相比，对于 PTO，时间需求的参数调整更加直接，也不那么保守。利用重建的状态，开发了一种量化控制器，在执行器故障下，将姿态跟踪误差在预设时间间隔内（物理上可实现）收敛到原点的小邻域内。该控制器具有三个特点：（1）导出了一个无切换的避免奇异层，以确保控制信号的有界性。（2）使用滞后量化器对控制信号进行离散化，以便在数字机载平台上应用，并减少通信负担。（3）在离散化控制信号下，通过两个设计参数预设姿态跟踪误差的调整时间，而不使用性能函数，避免了违反性能函数和现有量化预设时间控制器突然崩溃的风险。此外，使用非光滑分析方法和 Lyapunov 方法进行稳定性分析。最后，在 HLV 上的数值模拟验证了所提出控制系统的有效性。
