Considering attitude-only measurements, physical limitations of actuator and state-independent observer time, a distributed velocity-free attitude coordination control problem for multiple formation spacecraft with torque saturation is studied in this work. Initially, aiming at speeding up the convergence rate and realizing the maximum value of the convergence time without requiring prior knowledge of the initial system state values, a fixed-time observer is constructed to estimate the desired time-varying states in fixed time. Then, a filter system is developed for the spacecraft with attitude-only measurements. With the application of the fixed-time observers and the filter systems, a distributed velocity-free attitude coordination controller with torque constraint is designed to grantee that the leader with desired state trajectory can be tracked coordinately by the formation spacecraft. Finally, the performance of the proposed controller is demonstrated by simulation results.

中文翻译：

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具有转矩约束的分布式无速度姿态协调控制

考虑到仅姿态测量、执行器的物理限制和与状态无关的观测时间，本文研究了具有扭矩饱和的多编队航天器的分布式无速度姿态协调控制问题。最初，为了加快收敛速度​​并实现收敛时间的最大值，而不需要先验系统初始状态值，构造了一个固定时间观测器来估计固定时间内所需的时变状态。然后，为仅进行姿态测量的航天器开发了一个过滤系统。随着固定时间观察者和过滤系统的应用，设计了具有扭矩约束的分布式无速度姿态协调控制器，以保证编队航天器可以协调跟踪具有所需状态轨迹的领导者。最后，通过仿真结果证明了所提出控制器的性能。