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Aiming at the attitude control of an asymmetric morphing-wing aircraft, a compound control system is proposed. Based on the dynamic model of the asymmetric morphing-wing aircraft, the morphing wing is regarded as a new active control mechanism and the condition of using the asymmetric morphing wing is determined. A control strategy for the allocation of the control commands is designed by the logic function. The disturbance caused by the morphing wing is estimated by the extended disturbance observer and the variable structure control method with global sliding mode is used to design the compound control system which restrains the violent changes in parameters and disturbance during the process of morphing. According to the simulation, compared to the fixed-wing aircraft, the effectiveness of the asymmetric morphing wing is assessed and the robustness of the controller is also evaluated by the pertubation of the parameters. [ABSTRACT FROM AUTHOR]

This paper presents a novel coupling characterization based robust control scheme for hypersonic vehicles. First of all, the attitude equations of a hypersonic vehicle are denoted, and the error dynamic model of the hypersonic vehicle is obtained based on the backstepping technique. Then, a robust coupling-based control scheme is proposed combining with the disturbance observer, and the asymptotic convergence is guaranteed through the sliding mode compensation. Finally, the integral absolute error (IAE) performance index is introduced, and the better performance of the proposed method is proven theoretically. The proposed method not only guarantees the asymptotic stability and the strong robustness, but also improves the dynamic performance via considering the coupling characterization into the controller design. The aerodynamic parameters perturbation and actual actuator constraints are considered in the numerical simulations, and the results demonstrate the validity of the control method in this paper. [ABSTRACT FROM AUTHOR]

Based on drag acceleration profile, a predictor-corrector guidance law which can guide longitudinal motion and lateral motion synergistically is proposed in this paper. The drag acceleration profile is designed through interpolating between upper drag boundary and lower drag boundary, and then corrected to eliminate the range error. The altitude error is eliminated by adjusting attack angle. The lateral error is eliminated by regulating the reversal time of bank angle. Comparing with the traditional methods, the proposed one can correct the 3-dimensional motion of the vehicle. Using interpolated drag acceleration profile, the flight constraints can be easily dealt with. Moreover, in a correction cycle, the method in this paper only needs twice trajectory predictions, which is favorable for on-board calculation. The simulation results indicate that the proposed guidance law has a high precision and robustness. [ABSTRACT FROM AUTHOR]

Two typical flight modes of hypersonic glide vehicles, equilibrium glide and skip glide, are researched in the paper. Firstly longitudinal kinematic models for hypersonic glide vehicle are established. Relative functions between velocity, height and fight path angle are deduced, and the changing laws of dynamic pressure, total load factor and heating rate with velocity are analyzed in the equilibrium glide mode. In addition, analytical equations between state parameters are presented under the condition of constant lift-drag-ratios. Numerical simulation method is applied to explain the effect of the initial parameters on the skip glide trajectory. The study can help improve the understanding and provide guidance for missions like trajectory prediction, planning and guidance. [ABSTRACT FROM AUTHOR]

On-line trajectory plan methods are of no guarantee of real time for using optimization searching algorithms. They are unpractical to be adopted in engineering application for reusable launch vehicles (RLV) in terminal area energy management (TAEM). An prediction and acquisition straight line (PASL) phase is added before the heading alignment cone (HAC) to accomplish the TAEM trajectory on-line planning in advance, thus decreasing the requirement for the real time performance. The vehicle's initial states of the TAEM phase referred to as the terminal states of the PASL phase can be predicted by calculating the analytic solution of three-degree freedom motion equations with zero aerodynamic angle. Taking dynamic pressure, normal acceleration and bank angle as constraints, it is transformed into a non-linear planning problem to generate the TAEM trajectory. The objective function is to search for the optimal HAC position with a minimum heading error to enter the HAC. In addition, a pneumatic-angle directive (PD) feedback tracking law is designed, where the open-loop commands are available once the trajectory is obtained. Finally, an illustrative example is given to confirm the efficiency of the TAEM method based on trajectory prediction. [ABSTRACT FROM AUTHOR]