Hui-Jie Sun

This article investigates the attitude-position integrated control of spacecraft formation in the presence of inertia uncertainties and external disturbances. The mathematical model of the spacecraft formation attitude-position integrated control system is established using dual quaternion representation. A novel predefined-time extended state observer (ESO) is developed to estimate the total perturbation, which includes both inertial uncertainties and external disturbances in the system model. Compared with existing predefined-time ESOs, the proposed observer eliminates redundant differential terms and provides a more rigorous theoretical proof. Based on the estimates obtained from this predefined-time ESO, a predefined-time attitude-position integrated control scheme for spacecraft formation described by dual quaternions is proposed for the first time. Furthermore, the closed-loop system’s predefined-time stability is proven using Lyapunov stability theory. Finally, a series of comparative simulations validates the performance and effectiveness of the proposed predefined-time ESO and the presented control strategy.

This article investigates the orbit tracking control problem for the deep space probe flying around an unknown asteroid under completely unknown dynamics. First, an orbit tracking control model for the relative motion of the probe to the asteroid is established. Then, a model-based controller is designed for the optimal tracking control problem and the asymptotic stability of the closed-loop system is proved. Next, an adaptive dynamic programming (ADP) algorithm based on policy iteration is adopted to obtain a model-free suboptimal controller that approximates the previous model-based controller, followed by the convergence analysis. Specifically, by collecting some data online, a system of high-order linear equations is constructed and then solved to obtain parameters utilized in controller construction. Finally, numerical simulations are provided to validate the effectiveness and the performance of the proposed control method.

This article investigates the prescribed-time control for a novel tendon-driven space manipulator with uncertainties and deformations in the extensive operations. Considering the elastic potential energy loss moment of the rope and the coupling of the joint motion under the coordinated drive of multiple motors, the dynamics model of the space manipulator is established by the Lagrangian method. The dynamical model is transformed into a class of second-order fully actuated nonlinear systems using an equivalent transformation. Then, a practical prescribed-time controller is designed using the high-order fully actuated system approach. The designed control method is characterized by two features: first, high tracking accuracy is achieved by transforming the nonlinear system control problem into a linear system control problem through fully actuated system approaches; second, fast trajectory tracking is obtained by using the prescribed-time control technique. Finally, numerical simulations and physical experiments are performed to demonstrate the effectiveness and superiority of the proposed control method.

Aiming at the characteristics of air-breathing combined power vehicles with many constraints in the ascent stage and high precision requirements of terminal windows, a flight corridor design method based on the velocity-altitude profile is proposed. The velocity-altitude profile is used to describe the flight corridor, the relationship between constraints and velocity and altitude is analyzed, and the constraints contained in the upper and lower boundaries of the corridor are determined. Based on the analysis of the constraints, the angle of attack that satisfies the constraints and maximizes or minimizes the altitude at the current velocity is solved. A sample vehicle is used as an example to design and analyze the flight corridor in the ascent stage, and the calculation result shows that the method can be used for flight corridor design under multiple constraints in the ascent stage of the combined power vehicle.