This paper proposes a novel strategy to design a suboptimal attitude tracking control law for a near-space hypersonic vehicle (NSHV) based on the Koopman operator and stable manifold theory. The nonlinear vector field of the NSHV attitude model is locally Lipschitz continuous and can be approximated by a high-dimensional linear system over a compact set. Linear and nonlinear parts of the attitude dynamics are determined based on this system. Subsequently, the stable manifold theory is applied to determine the unconstrained approximated optimal control law that is used to further consider the control input constraints of the NSHV attitude model. The suboptimality of the control law is analyzed, and the local exponential stability of the closed-loop system with input constraints is proven. Furthermore, the eigenvalues for the closed-loop nonlinear attitude error dynamics are analyzed. After the control input saturation, the nonlinear closed-loop error dynamics of the NSHV can be approximated by a high-dimensional linear system with a minimal dimension. The eigenvalues of this linear system indicate the stability and time response characteristics of the attitude error dynamics of the NSHV. The numerical simulation results demonstrate the effectiveness and suboptimality of the proposed attitude tracking control law and workflow of the eigenvalue analysis.

Purpose To suppress fatigue damage and ensure structural safety, this paper aims to analyze the effect of the damage accumulation on the aeroelastic model of an air-breathing hypersonic flight vehicle (AHFV). Design/methodology/approach Initially, by constructing the modified longitudinal elastic model of an AHFV, the stress condition of the fuselage is analyzed, and the model differences with the rigid body are studied. Then, a new damage dynamic model is presented to describe the damage dynamic evolution. Finally, combining the damage model and the longitudinal model of the AHFV, the key variables affecting the damage accumulation are determined. Findings It is demonstrated that the elastic deformation must be considered when analyzing the damage characteristics of the fuselage and to determine the key variables that affect the damage accumulation, which provides a more accurate reference for improving the structural reliability and lifespan of AHFVs. Originality/value The novelty of this paper comes from the application of the force and stress models for the damage evolution of the AHFV and the development of a new damage model for the entire body with the elastic dynamics of AHFVs.

针对武装直升机发射火箭弹时产生的后坐力问题,提出了一种基于预设性能控制的后坐力补偿控制方法,以保证在火箭弹发射过程中载机的稳定性。首先,结合直升机姿态模型,分析火箭弹发射时产生的后坐力大小,以及后坐力对直升机姿态产生的影

This paper presents a novel suboptimal attitude tracking controller based on the algebraic Riccati equation for a near-space hypersonic vehicle (NSHV). Since the NSHV's attitude dynamics is complexly nonlinear, it is hard to directly construct an appropriate algebraic Riccati equation. We design the construction based on the Chebyshev series and the Koopman operator theory, which includes three steps. First, the Chebyshev series are considered to transform the error dynamics of the NSHV's attitude into a polynomial system. Second, the Koopman operator is used to obtain a series of high-dimensional linear dynamics to approximate each of the polynomial system's vector fields. In this step, our contribution is to determine a well-posed linear dynamics with the minimal dimension to approximate the original nonlinear vector field, which helps to design the control law and analyze the control performance. Third, based on the high-dimensional dynamics, the NSHV's attitude error dynamics is separated into the linear part and the nonlinear part, such that the algebraic Riccati equation can be constructed according to the linear part. Then, the suboptimal error feedback control law is derived from the algebraic Riccati equation. The closed-loop control system is proved to be locally exponentially stable. Finally, the numerical simulation demonstrates the effectiveness of the suboptimal control law.

针对可重复使用运载器（reusable launch vehicle,RLV）再入段常规约束、航路点约束、倾侧角速率约束和参数不确定问题,提出一种多约束鲁棒预测校正制导方法。首先,利用改进准平衡滑翔条件将常规约束转化为倾侧角幅值约束。其次,提出基于二分法快速迭代确定倾侧角翻转位置的航路点制导律,并将翻转速率约束转化为关于能量的约束,引入预测校正的计算中。然后,对于参数不确定鲁棒制导问题,提出基于标称升阻比和能量剖面对迎角及横程误差走廊在线调整的策略。仿真实验表明,在参数不确定情况下,RLV能够满足多约束条件和终端制导精度要求,验证了方法的有效性和鲁棒性。

为实现可重复使用运载器(Reusable launch vehicle,RLV)的再入段准确制导与鲁棒容错控制,提出了一种基于改进预测校正制导律和鲁棒容错姿态控制联合的方法.首先,设计改进倾侧角幅值模型和航迹方位角走廊的预测校正制导律,结合标称迎角剖

This paper studies the dynamic output feedback consensus control problem of linear heterogeneous multi-agent systems under the leader-follower formation with a dynamic quantizer. In the practical engineering, the status information of the unmanned aircraft vehicle (UAV) and the unmanned underground vehicle (UGV) is normally unmeasurable, which is difficult to design the state feedback controller for the UAV-UGV formation. Besides, in the communication topology of the leader-follower formation based on UAVs and UGVs, the signals should be quantized in each follower. However, the traditional static quantizer has quantization error, which affects the formation stability. Therefore, the control objective is to guarantee the UAV-UGV formation tracking consensus while improve the precision of the quantization. First, the followers and leader systems are based on the discrete-time model, and the output trajectory of the leader is time-varying. Then, a dynamic output feedback controller is provided with a dynamic quantizer to guarantee the tracking performance of the heterogeneous multi-agent systems with a leader. The followers can asymptotically track the leader system with L2 − L∞ control gains by solving a set of linear matrix inequalities (LMIs). Finally, simulation results demonstrate the effectiveness of the designed control strategies. © 2020, ICROS, KIEE and Springer.

This paper studies the dynamic output feedback consensus control problem of linear heterogeneous multi-agent systems under the leader-follower formation with a dynamic quantizer. In the practical engineering, the status information of the unmanned aircraft vehicle (UAV) and the unmanned underground vehicle (UGV) is normally unmeasurable, which is difficult to design the state feedback controller for the UAV-UGV formation. Besides, in the communication topology of the leader-follower formation based on UAVs and UGVs, the signals should be quantized in each follower. However, the traditional static quantizer has quantization error, which affects the formation stability. Therefore, the control objective is to guarantee the UAV-UGV formation tracking consensus while improve the precision of the quantization. First, the followers and leader systems are based on the discrete-time model, and the output trajectory of the leader is time-varying. Then, a dynamic output feedback controller is provided with a dynamic quantizer to guarantee the tracking performance of the heterogeneous multi-agent systems with a leader. The followers can asymptotically track the leader system with L₂ − L_∞ control gains by solving a set of linear matrix inequalities (LMIs). Finally, simulation results demonstrate the effectiveness of the designed control strategies.
© 2020, ICROS, KIEE and Springer.

针对无人直升机系统和控制器的不确定性,基于特征值摄动的思想设计了正规化非脆弱控制器,以保证系统具有良好的鲁棒性和飞行性能。首先,建立了无人直升机的非线性姿态动态的T-S模糊模型,然后,基于特征值摄动的思想针对系统的标称部分进