# Research on Backstepping Linear Active Disturbance Rejection Control of Hypersonic Vehicle
## 1 Citation  
Due to the advanced engine/body integration configuration of hypersonic vehicles, there is an obvious strong coupling relationship. At the same time, the large flight Mach number [1] makes the motion process of the hypersonic vehicle have strong nonlinear and fast time-varying characteristics, which brings many difficulties to controller design. [PERSON] et al. [2] put forward the active thermal protection of hypersonic aircraft in flight. [PERSON] et al. [3] put forward the use of air propulsion and elevator-to-elevator coupling to design a hypersonic vehicle controller. [PERSON] et al. [4] put forward a quasi-continuous high-order sliding mode (HOSM) controller based on full state feedback to track the step changes in speed and altitude. According to the characteristics of the longitudinal model, [PERSON] et al. [5] divided the aircraft model into two subsystems, including the altitude subsystem and the speed subsystem. [PERSON] et al. [6] summarized the fault-tolerant control anti-saturation considering the external disturbance of aircraft and the specified performance control considering transient performance constraints. In recent years, many scholars have conducted research on the design of hypersonic vehicle controllers. The literature [7] provides an overview of the current technical issues and challenges associated with the design of hypersonic vehicles. The cooperative guidance strategy of a multi-hypersonic vehicle system with flight constraints and cooperative constraints is proposed in the literature [8]. A variety of aircraft engine configurations using ABREAST are proposed in the literature [9]. Backstepping control, adaptive control [10], fuzzy control, robust control [11, 12], synovial membrane control [13], etc., have been used in controller design and have achieved excellent results. The research by [PERSON] et al. [14] combined feedback linearization and optimal control to design a robust controller for general systems with parameter uncertainties. The research by [PERSON] et al. [15] designed a high-order super-warping algorithm, but the algorithm had too many controller parameters. The research by [PERSON] et al. [16] designed a hypersonic vehicle control system using a synovial membrane disturbance observer and adaptive backstepping control. It achievedgood control effects. Backstepping control shows its unique advantages when designing the controller of a complex system. For example, hypersonic vehicles have parameter uncertainties such as variations and aerodynamic parameter uncertainties. Backstepping control can fully consider these influencing factors in the controller design, thus significantly improving the robustness of the system and ensuring the stable flight and precise control of the aircraft under various complexities [17]. In reference [18], a distributed actuator fault compensation scheme for a hypersonic vehicle is designed based on model transformation backstepping control, which improves the control accuracy in the case of actuator failure. However, these control methods still have shortcomings. In the face of random disturbances, the tracking error of the controller is relatively large. active disturbance rejection control (ADRC) can observe the disturbance, which greatly enhances the robustness of the system. Reference [19] proposes a 2-degree-of-freedom control based on an extended state observer for estimating and eliminating total disturbance. Reference [20] proposes the application of linear flatness control along with active disturbance rejection control (ADRC) for the local stabilization and trajectory tracking problems in the underactuated ball and rigid triangle system. An adaptive robust control device is proposed in reference [21]. A linear active disturbance rejection controller (LADRC) is designed for NMAMS single-axis trajectory tracking control in reference [22]. The literature [23] introduces the theory of ADRC. The research by [PERSON] and [PERSON] [24] designed a hypersonic vehicle controller based on ADRC.