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Different from traditional aircraft, hypersonic glide vehicles (HGVs) possess stronger maneuverability and a higher flight speed (generally higher than 5 Mach), making trajectory prediction very complicated. Several works have been conducted in this field, which usually analyze the motion characteristics of the HGV first and then use a Kalman filter to track and predict the trajectory. In this way, the accuracy of prediction depends on how to model the control parameters of the target vehicle. The core idea of this paper mainly concerns treating the HGV trajectory prediction as a multivariate time series forecasting problem since HGV trajectories are special multivariate time series with nonperiodic temporal patterns. Moreover, capturing the hidden dependencies between time steps and different time series ensures the accuracy and robustness of predictions. Recently, recurrent neural networks have been widely used in predicting data with temporal patterns between several time steps; however, they fail in capturing nonperiodic temporal patterns. Therefore, we propose a brand-new model named the dual-channel and bidirectional neural network (DCBNN) to intelligently predict the trajectory of hypersonic vehicles in undetectable areas, especially for those with complex maneuver models. DCBNN is constructed with a nonlinear component and a linear component to collect both nonlinear and linear features from input data to improve robustness. Moreover, a dual-branch architecture is utilized in the nonlinear component to capture the complex and mixed dependencies between long-term and short-term patterns. Experiments reveal that the proposed method is effective and intelligent.

In this paper, the parallel physical optics (PO) method is used to calculate the dynamic radar cross section (RCS) of the hypersonic vehicle covered with plasma sheath, and the Doppler spectra of the hypersonic vehicle at different reentry altitudes are calculated in the same time domain. The results show that: The relative motion between hypersonic vehicle and Space-borne Radar results in small frequency shift of Doppler spectrum; In addition, the backscattering echo intensity of different frequency electromagnetic (EM) waves at different positions of the vehicle covered with plasma sheath is different with time, which leads to the Doppler spectrum broadening of hypersonic target. The research results provide technical means and data support for hypersonic targets echo detection and feature recognition.

In this paper, we study cooperative tracking problem in hypersonic missile defense scenario. To this end, we propose an enhanced cubature Kalman filtering algorithm for cooperative state estimation of the incoming target with bearing-only measurements, the proposed cooperative filtering scheme is fully decentralized and works under any balanced and connected communication topology. Simulation results verified performance of the proposed algorithm.

The penetration trajectory optimization problem of hypersonic gliding vehicles (HGV) with multiple constraints is investigated. Firstly, the attack-defense confrontation models are established, where the HGV is required to achieve effective penetration under interception missile using Proportional Navigation Guidance (PNG) method. Then the original penetration trajectory optimization problem under multiple constraints is converted into a second-order cone programming (SOCP) problem through linearization, discretization and convexification manipulation. The online sequential convex optimization algorithm is used to solve the SOCP problem. Finally, numerical simulations are given to demonstrate the effectiveness of the method and penetration effect.

In this paper, an backstepping control scheme with state constraint is proposed for a hypersonic flight vehicle model with the speed constraints and unknown disturbance. The Nonlinears Disturbance Observer(NBO) is used to approximate the unknown disturbance. It is commonly known that the stability and security of the HFV will be weakened when the constraints are violated. Thus, the control problem of the speed constraints for the HFV is a very important task because of the demand of the handing safety. The auxiliary system and the time-varying barrier Lyapunov functions are used to guarantee the constraints of the angular velocity not violated, and it can prove the stability of the closed-loop system. Finally, a simulation example for the GHV is employed to show the feasibility and rationality of the proposed approach.

This paper discusses the problem of avoiding threats during the cruising flight of hypersonic vehicles (HV). Considering the constraints on kinematics of HV and changing environments, this paper proposes two methods of trajectory planning that taking the overload or the rotational angular velocity of the ballistic deflection angle as actions of agent. Meanwhile, the agent’s policy is optimized with policy gradient method, and Proximal Policy Optimization (PPO) and Soft Actor-Critic (SAC) are used for comparison. Experimental results show that PPO and SAC have similar performance in penetration missions. Moreover, in the complicated flight environment, the method of taking overload and exploration distance as actions has a higher penetration success ratio.

Skip trajectory characteristics of hypersonic glide vehicles are analyzed from the perspective of small perturbations and large deviations based on the study of the equilibrium glide. Qualitative analysis and quantitative analysis are proposed for skip glide trajectories caused by small perturbations, respectively. The numerical simulation method is present for skip glide trajectories under the condition of large deviations. The study herein can help to deepen the understanding of skip trajectory essence of hypersonic glide vehicles and provide guides for missions such as trajectory approximation.

This paper investigates the backstepping control problem for air-breathing hypersonic vehicles (AHVs) using deep reinforcement learning (DRL). By utilising the prior knowledge of a widely-accepted AHV model, the proposed DRL-based controller has a high learning efficiency as well as keeps a simple structure. With the help of deep deterministic policy gradient, the intractable parameter adjustment in traditional backstepping designs for AHVs is well handled with full considerations on actuator magnitude and rate constraints. A Monte-Carlo simulation is provided to show the effectiveness of the proposed DRL-based control.

A real-time three-dimensional constrained trajectory prediction method for Hypersonic Glide Vehicle based on 3-D flight corridor is developed in this paper. The approach uses a 3-D profile which is constrained by the well-known Quasi-Equilibrium Glide Condition to predict the whole trajectory online. The trajectory prediction is done by solving a reduce-order systems of differential equations in the redefined coordinate frame using a semi-analytical algorithm. The earth rotation angular speed is regarded as a system deviation which is countervailed in the latter calculation. The effectiveness and the efficiency of this algorithm is demonstrated by being compared with a high-precision numerical method. The algorithm is able to predict a whole trajectory in about 0.01 to 0.02 seconds on a personal computer.

During the ascent and re-entry phase of a space vehicle in the Earth's atmosphere, it is well known that the surface of the thermal protection system covering the vehicle changes its physical properties due to the severe aerothermodynamic loads generated during the flight. Such phenomena are under investigation in the hypersonic plasma ground facilities with various techniques. At the CIRA-Plasma Wind Tunnel (PWT) the Test Engineer Team (INPP) has improved the new technique in the INPP laboratory for the investigation of the material surface spectral emissivity variation during the development of hot tests performed in the SCIROCCO and GHIBLI hypersonic plasma facilities. It is based on the use of one optical device of the dual-colour type, that now is able to measure the two and single-colour temperatures of the material surface simultaneously and to obtain the trends of the spectral emissivity at the operative wavelength of the device. The present paper will show the results obtained during the development of a test campaign, giving evidence of the kindness of the technique.

The paper presents an effective modeling method for echoes of hypersonic and space targets which is devoted to generation of simulated echoes for long-range multistatic passive radar dedicated for detection of very fast object like rockets, satellites and modern hypersonic missiles. As usually the signal is integrated for a long time for space and high-flying objects, the modeling should be accurate for long observation time. To improve the detection capability and also to achieve non-cooperative target identification the multistatic geometry is often considered. The proposed method allows for precise generation of modeled echoes in multistatic geometry to be performed. It should be kept in mind that not only range but also very high phase accuracy must be achieved for coherent multistatic processing.

In the design of hypersonic cruise vehicles, great effort is demanded to improve the performances of subsystems, namely structure, aerodynamics, and propulsion. Herein, effort demanded to realize a subsystem performance is quantified by technical merit. To achieve a feasible design, excessive technical merit of any one subsystem should be avoided. Accordingly, a lowest-technical-merit (LTM) design methodology has been proposed in this work. By this methodology, the design problem could be interpreted into a parametric optimization. The solution to such an optimization corresponds to the highest feasibility. The methodology has been implemented on two cases: deriving a hydrocarbon-fueled long-range cruiser from Boeing X-51A, and a hydrogen-fueled LAPCAT scenario from PREPHA. The simulation results show that LTM could achieve optimal allocations while satisfying different payload/range performances. The design methodology could help to improve the feasibility of hypersonic cruise vehicles. Furthermore, it could also be used in the design of other systems.

This paper presents a performance recoverable control scheme for air-breathing hypersonic vehicles (HSVs) with nonminimum phase characteristics. As elevator and throttle are the only two control inputs available for longitudinal trajectory tracking of HSVs, there are two representative problems emerged. One is the nonminimum phase behavior in pitch dynamics of HSVs due to elevator-to-lift coupling, which prevents the application of standard inversion-based control techniques. The other is the engine performance recovery control with the disabled propulsion system, when flight states of HSVs exceed the safe working boundary, causing engine flameout. In view of the above, a comprehensive control scheme is proposed to realize performance recoverable and high-precision trajectory tracking of nonminimum phase HSVs. First, a dynamic integral sliding-mode (DISM) control method based on the Byrnes-Isidori (B-I) normalized form is proposed, achieving asymptotic tracking of velocity and flight path angle (FPA) while stabilizing internal dynamics. The control method transforms the FPA tracking problem into a stabilization problem of an augmented system consisting of internal dynamics and dynamic compensator, making closed-loop pole adjustable, and thus improves the tracking performance. Second, on this basis, a performance recoverable control scheme is proposed to achieve the automatic performance recovery of HSVs when the engine flameout occurs due to the stall of the HSVs. It achieves temporary acceleration by adjusting the trajectory, thus obtaining the conditions for engine restart. The simulations of the nominal condition and engine flameout condition are presented, respectively, to verify the proposed control scheme. From the simulation results, the proposed control scheme is shown to have superior tracking accuracy with internal dynamics stable, and the robustness is fully verified by the Monte Carlo simulations. Especially, speed autonomous recovery and engine restart are achieved during the engine flameout, which demonstrates the effectiveness of the proposed performance recovery control scheme.

The flight dynamics of air-breathing hypersonic vehicles (AHVs) is highly nonlinear, multivariable coupling, and includes inertial uncertainties and external disturbances, which require strong robust and high accuracy controllers. Considering the inertial uncertainties and external disturbances, the flight control system of AHVs can be designed as the general control issue for an uncertain nonlinear system with mismatched disturbances. To achieve the target of disturbance rejection, this paper proposes direct and indirect disturbance rejection control approaches to investigate the flight control of AHVs. For different levels of system disturbance, the typical direct and indirect disturbance rejection control schemes are presented and compared with each other. Finally, simulation results illustrate the advantages and application limits of the direct and indirect disturbance rejection control approaches.

Periodic cruise has been proven an effective trajectory to conserve fuel and alleviate aerodynamic heating for hypersonic cruise vehicles (HCVs). This work studies how to adopt an HCV with active cooling to periodic cruise. In this adaption, payload capacity is to maximize, whereas the cooling requirement is to reduce. The differences in requirements for subsystems between periodic and steady cruises have been made clear. The results indicate that periodic cruise principally transfers the burden of thermal protection to the structure, and that periodic cruise is more effective to trade payload capacity for larger reduction of cooling requirement. Afterward, impacts of design parameters of the vehicle on payload capacity and cooling requirement have been discussed. The results indicate that insulation thinner than 3 mm, a planform loading lower than 220 kg/m2, or a large engine is not suggested for the vehicle studied herein. This work figures out the correlation between design parameters of vehicle and features of periodic cruise trajectory. It could help to improve the feasibility of periodic cruise for a hypersonic vehicle, which is significant for realization of the long-range hypersonic cruise.

For detection and tracking of a near space hypersonic maneuvering target in a heavy clutter environment, a novel transform domain method called Variable-Diameter-Arc-Helix Radon Transform (VDAH-RT) is proposed as a tool to integrate observations along the maneuvering path. Considering the 3D maneuvering trajectory is like a variable diameter arc helix, the trajectory of near space hypersonic target can be modeled by a variable diameter arc helix. Since the maneuvering parameters are unknown, variable diameter arc helixes with different parameters can be used to match the maneuver track. Using the idea of Radon Transform(RT), the problem of maneuvering trajectory detection and tracking is transformed into the energy peak detection problem in VDAH-RT parameter domain. This Variable-Diameter-Arc-Helix Radon Transform (VDAH-RT) technique extends the RT or HT(Hough Transform) for straight-line features detection to an arbitrary curve trajectory. The results demonstrate that the proposed algorithm provides great advantage in the detection and tracking of a hypersonic maneuvering dim target.

Aerodynamic shape optimization (ASO) of hypersonic lifting body has become a significant research topic due to its significant performance advantages. As a universal parameterization, the free form deformation (FFD) technique has benefits including geometric independence, random deformation, and mesh synchronization. In this paper, an effective design method to apply the FFD technique in the ASO of a hypersonic lifting body is presented. Some commonly used basis functions are researched in FFD modeling of the windward side of a typical lifting body, including the Bernstein polynomial, the B-spline function, and the non-uniform rational B-spline (NURBS) function. An efficient aerodynamic simulation method combining Euler equations (non-viscous component) and skin friction drag (viscous component based on the compressible turbulence model) is then developed to minimize computational requirements. The accuracy of the proposed method is validated, and a significant decrease in processing time is observed. In addition, a kriging surrogate model combined with infilling sampling expected improvement (EI) criterion is developed to improve optimization efficiency. To obtain a lifting body with high lift-to-drag ratio that satisfies inner loading constraint, a baseline is optimized by manipulating its shape using the NURBS-based FFD technique. The results show that the optimal shape displays outstanding aerodynamic performance, and the effective design method can provide practical support for ASO of the hypersonic lifting body.

Accurate estimation of surface heat flux at rarefied operating conditions is indispensable for the design of a reliable thermal protection system for Reusable Launch Vehicles. At rarefied atmospheric conditions, conventional continuum-based numerical methods fail to predict the flow field properties, Direct Simulation Monte Carlo (DSMC) method is recommended for the flow field predictions. In the present work, hypersonic flow over a flat plate was numerically simulated using dsmcFoam+ solver for near-continuum flow regime. The solver is validated for hypersonic flow over a flat plate case with respect to the literature and the results are analysed in detail to understand viscous interaction. Further, a parametric study was conducted by varying Mach number from 4 to 6 and the contours of pressure, density, and temperature distribution over a flat plate at supersonic to hypersonic flow conditions were analysed. Local pressure coefficient, surface heat flux, and heat transfer coefficient for the given operating conditions are also estimated and the results are discussed. The extension of this study for wedge and Orion geometries is under progress.

Compared to conventional ballistic vehicles and cruise vehicles, hypersonic vehicles exhibit unprecedented and clearly superior abilities. Hypersonic glide vehicles (HGVs) travel at speeds faster than Mach 5, enabling them to fly at least one mile per second. Furthermore, they possess maneuvering capabilities that assist them in evading defense systems, increasing precision of their impact points, and hindering prediction of their final destinations. In this paper, we examine machine learning methods to automatically identify different hypersonic glide vehicles and a ballistic reentry vehicle (RV) based on trajectory segments. Trained on aerodynamic state estimates, our methods analyze key vehicle maneuvers to classify vehicles with high accuracy. We also identify vehicles with higher accuracy as time after liftoff (TALO) increases and more data becomes available for analysis.

This paper addresses trajectory optimization for hypersonic vehicles under atmospheric and aerodynamic uncertainties using techniques from desensitized optimal control (DOC), wherein open-loop optimal controls are obtained by minimizing the sum of the standard objective function and a first-order penalty on trajectory variations due to parametric uncertainty. The proposed approach is demonstrated via numerical simulations of a minimum-final-time Earth reentry trajectory for an X-33 vehicle with an uncertain atmospheric scale height and drag coefficient. Monte Carlo simulations indicate that dispersions in the final position footprint and the final energy can be significantly reduced without closed-loop control and with little tradeoff in the performance metric set for the trajectory.

In order to reduce the weight of hypersonic vehicle, improve its range and load capacity, the design concept of slender body and light weight is generally adopted, which makes its rigidity reduce and flexibility increase, and then leads to the reduction of elastic mode frequency, which is more and more close to the rigid body mode. in addition, it is also the static instability layout, so the aero-elastic coupling problem becomes particularly important. The “filter optimalization based on self-adaptive cuckoo search algorithm + Supertwisting active elastic control methods ”are studied to solve the problem. Based on the signals of attitude angle, angular velocity, generalized coordinates and the changing rate of generalized coordinates, the fast and accurate convergence of attitude tracking errors are realized under the premise of avoiding the excitation of vehicle vibration mode. The effectiveness and robustness of the control method are verified by mathematical simulation.

At hypervelocity flows the design place a major role. To sustain such impact the design, need to be more aerodynamic. Blunt body is key factor to achieve and sustain those hypersonic velocities that is mainly focused beyond Mach number 5. Blunt body design in aerodynamic and structural aspects become more crucial factors in hyper velocity vehicles. The paper mainly focuses on effective blunt body design. In order to achieve the effectiveness various radius of curvature taken into account and comparative study were done. Along with that flow compressibility, chemical reaction, aerodynamic heating, stagnation conditions were discussed. Extensive review was done to select most efficient blunt body design in both aerodynamic and structural aspects

In this paper, a novel robust back-stepping fault- tolerant control scheme is proposed, which enables hypersonic reentry vehicles with model uncertainties to accurately track the attitude commands under the condition of both unknown actuator faults and external disturbances. Firstly, a control-oriented hypersonic reentry vehicle model is established on the basis of regarding three factors mentioned above as lumped disturbance. Then, a fixed-time observer is used to achieve the fixed-time lumped disturbance estimation. Based on the disturbance observer and back-stepping technology, the proposed fault-tolerant control laws are designed to ensure control performance. Meanwhile, the “differential explosion” problem is solved by the sigmoid function-based tracking differentiator. Finally, the stability and effectiveness of the proposed controller are verified from theoretical analysis and extensive numerical simulations respectively.

A funnel control approach, guaranteeing output behavioral performance, is studied for flexible air-breathing hypersonic vehicle. A performance function without requiring an accurate initial error is designed for the sake of guaranteeing tracking errors with preseted transient performance. Neural approximation approach is applied to reject unknown vehicle dynamics. Moreover, improved regulation laws are developed for neural networks applying minimal-learning-parameter scheme, which reduces the computational costs and ensures neural approximation precision. The stability of closed-loop control systems is proved via Lyapunov synthesis. Finally, the presented simulation results show the tracking performance of the addressed approach.

This paper proposes a combined guidance law based on differential geometry and true proportional guidance (TPN). Due to the increase of the interceptor acceleration component perpendicular to the speed direction, the line-of- sight angular rate can be converged quickly, and the convergence rate of the miss distance is faster than that of TPN. Therefore, the combined guidance law can intercept the target in a short time, reducing the possibility of target escape. This paper gives a numerical simulation example under the two conditions of large maneuvering and snake maneuvering of the target, both of which achieve effective interception of the target. Therefore, the designed combined guidance law is effective for intercepting hypersonic large maneuvering targets.

A prescribed performance back-stepping control approach is presented for a generic air-breathing hypersonic vehicle (AHV) with the uncertainties of the model and unknown disturbance. By prescribed performance, a novel performance function characterizing the error convergence rate, maximum overshoot and steady-state error is designed for the output error transformation without initial errors. In order to enhance the robustness of controller, the novel nonlinear disturbance observers (NDOs) based on tangent sigmoid tracking differentiators (TSTDs) are introduced to estimate and compensate the uncertainties of the model. To eliminate the "explosion of term" of back-stepping control strategy, sliding mode differentiators (SMDs) is applied to obtain the derivatives of virtual control laws. Finally, the tracking performance the proposed control approach is testified by simulation results.

Since the hypersonic vehicle has a strong sensitivity to the initial parameter values during the trajectory optimization process, a control vector parameterization method based on Gaussian distribution time nodes is proposed, and related solutions are given. By solving the zero point of the Legendre polynomial, the time nodes with Gaussian distribution in the entire control time domain are obtained. Then the control vector is parameterized by using the obtained new time grid, and a high-quality control parameterization strategy is achieved. The numerical results show that the proposed method can increase the performance index of downrange and flight time of hypersonic unmanned system.

For a hypersonic cruise vehicle (HCV) avoiding unknown threats from ground or space, dynamic path planning is an essential issue to fly safely in near space. Q-learning is the most typical one of reinforcement learning methods that has been effectively used for robotic path planning. However, few works is reported for an HCV with hypersonic flying characteristics considered. In this paper, a Q-learning based dynamic path planning method is presented. In the method, the vehicle is assumed as a mass point with time-invariant altitude and velocity for simplicity and the flight zone of the vehicle is modeled as an average grid map, where an e-greedy strategy is designed to establish the Q-learning algorithm. A simulation case has illustrated the effectiveness of the given method and shows that the method is suitable for the cruise phase path planning of an HCV.

The problem of adaptive tracking control for hypersonic vehicles with input saturation constraints and mismatched disturbances is studied. Firstly, the longitudinal hypersonic vehicle model is transformed into a linear form with mismatched disturbance by feedback linearization method. Then, a high-order disturbance observer is established to estimate the mismatched disturbances and their high-order derivatives quickly online. Based on the disturbance observation information, a new sliding mode surface is designed to ensure the stability and control accuracy of the system state under the action of external disturbance. At the same time, the input saturation problem is transformed into the time-varying gain problem by means of the mean value theorem, and the gain is estimated online by the adaptive law of Nussbaum function, and the actual stability of the closed-loop system under input saturation constraint is proved. Simulation results show that the proposed method can guarantee the good tracking performance of the aircraft considering input saturation and external disturbance.

A feasible and viable means for performing surveillance of a hypersonic vehicle is space-based system, which has been used for providing tracking results of near-space vehicles. In this paper, an adaptive infrared tracking method to a hypersonic cruise vehicle (HCV) is proposed. This approach contains three inherent parts: coverage analysis of the system, a space-based bearing-only positioning, and an adaptive tracking approach. An adaptive scheme based on the coverage analysis and the positioning results is proposed to achieve high estimation performance and guarantee generality. Simulation results for an adaptive scaling unscented Kalman filter (ASUKF) indicate the effectiveness of this approach.

For multiple hypersonic vehicles cooperative to attack a stationary target with time-varying velocities in dive phase, a finite-time cooperative guidance law is proposed. Firstly, this paper analyzes the characteristics of hypersonic vehicles in dive phase, and divides the terminal guidance process into two parts; that is, two relative motion equations are established to describe longitudinal and lateral directions. Secondly, in the longitudinal line of sight direction, the relative position difference and lineof-sight velocity difference between each vehicle participating in the attack missions and its neighbors are introduced as error terms into the guidance law. Finally, in order to achieve the convergence of the horizontal and vertical line-of-sight angles, a finite-time sliding mode guidance law is designed, and an adaptive disturbance observer to estimate the upper bound of time-varying disturbance is propose. The Lyapunov function is used to prove the finite time convergence of the proposed cooperative guidance law, and the simulation results verify the correctness and effectiveness of the designed cooperative guidance law.

Based on the periodic maneuvering conditions in the near space, this paper makes an in-depth study of Sine Wave model. When the preset maneuvering angular rate of Sine Wave model is consistent with the real maneuvering angular rate of the target, the tracking accuracy of the target is the highest. But the maneuvering angular rate in the real situation is often unknown or even changing. In this paper, a maneuver detection method based on the framework of Kalman filter is proposed for the variable maneuvering angular rate situation of near space hypersonic vehicles during the cruise segment. At the same time, an adaptive adjustment method of filter parameters and model parameters is given. Finally, the simulation proves the effectiveness of the improve model.

This work will focus on an overview of current development in hypersonic technology and problems associated with sustained hypersonic flight. The main objective of this work is an overview of engineering challenges that need to be overcome to allow the development of a new era of an ultra-high-speed aircraft with the ability to achieve sustained hypersonic flight. This review of the literature has gathered several important findings.

The development of Near-space hypersonic vehicle brings new challenges to national security defense systems. In order to solve this problem, this paper introduces the characteristics of near-space hypersonic vehicles, analyzes the current interception strategy, and gives some suggestions on this. It is believed that head-pursuit interception based on air lunch interception and researches on guidance and control can be used as the main research direction of near-space hypersonic vehicle interception strategy.

The attitude control issue for hypersonic vehicles (HSV) with coupling analysis is presented in this paper. An auxiliary variable is introduced to identify the effects of coupling terms that are negative or beneficial for the attitude stabilization. To handle the environmental uncertainties and aerodynamic perturbations involved in the hypersonic vehicles flight control system, a modified gain adaptation strategy is presented to tackle these terms that are limited but with unknow bounds. Then, a robust control scheme containing the coupling effect identified terms is constructed to deal with the robustness and coupling issues. It is proved that the utilized control scheme can enforce the tracking errors to a small vicinity of the origin in finite time. Finally, numerical simulations are conducted to demonstrate the provided controller.

RCS modeling of a typical hypersonic vehicle and its plasma sheath was investigated. The plasma parameters were analyzed to determine which were most dominant for accurate RCS prediction. HF was determined to provide BLOS detection and good conductivity of the plasma, for optimum RCS.

Hypersonic vehicles have strong maneuverability, and the method of trajectory prediction is different from traditional aircrafts. The current research on hypersonic vehicle trajectory prediction is usually aimed at the full trajectory prediction, and there are few methods for hypersonic vehicle trajectory prediction in specific scenes. In this paper, aiming at the scene that hypersonic vehicle be not observed in the blind area of land-based radar, a trajectory prediction method of hypersonic vehicle is proposed, which is realized by predicting the control quantity. According to the constraint characteristics, aerodynamic characteristics and motion characteristics, the characteristic function is established. And on the basis of the priori information from the observed data, the conditional random field model is established to predict the control quantity. The trajectory in the blind area is calculated according to the predicted control quantity. Finally, the effectiveness and feasibility of the trajectory prediction method proposed in this paper are verified by case study.

The paper describes the methodology and the design process of a Model Predictive Controller (MPC) that has been applied to solve Missile-on-Missile Interception. The MPC combines the control and guidance laws to create an ideal control law with much higher performance and guarantees strike with a wide range of target and missile parameters. The MPC is also able to handle actuator delay and hence is more practically suited than traditional guidance/control schemes. Also, MPC satisfies sensor/seeker angle constraints, actuator constraints, angle of attack constraints, and fin deflection angle constraints, thus making it more versatile and powerful than any analytical method-based control/guidance schemes. The only disadvantage is the higher computational cost requirements, which will be easily mitigated in the future with the advancements of powerful microprocessors. The performance of the MPC is demonstrated in simulations where the missile is a standard supersonic missile but the target is a maneuvering hypersonic missile with initial separation of just a few kilometers.

Conventional drug delivery relies on oral uptake and injection, which may be painful and cause side effects to the patients. To overcome these drawbacks, transdermal delivery based on micro/nanoscale devices has been proposed. Here, we developed a new transdermal delivery approach using MEMS fabricated hypersonic system. The GHz resonator could locally generate high acoustic pressure in liquids and further induces ‘liquid needles’ to enhance the drug permeation to the skin. Dextran was used as the drug models for in vitro delivery through semipermeable membrane and excised rat skin. The influence of delivery time, applied power and molecular weight of drugs were investigated. The results show a good controllability and easy to operate. With the advantages of low energy consumption and miniaturization, this approach demonstrates a good alternative for current transdermal delivery system.

The hypersonic vehicles have the characteristics of high flying height, high speed and strong maneuverability. Current early warning systems typically allocate resources only for conventional targets, and there are few resource allocation methods for hypersonic vehicles. In this paper, the Markov model of hypersonic vehicles is established based on the motion characteristics of the target, and an early warning resource allocation method based on hidden Markov model is proposed. Among them, based on the information entropy, the information generated by the consumption of unit resources is used as the objective function of resource allocation, so that resources can be used reasonably. Finally, the validity and feasibility of the proposed model are verified by case study.

This paper studies the tracking problem of hypersonic vehicles subjected to external disturbances, modeling uncertainty, and input saturation. The adaptive anti-saturation control scheme is designed based on the first-order command filter, dynamic surface control and auxiliary system. The proposed control strategy not only uses adaptive algorithms to estimate the external disturbance, but also introduces an auxiliary system to solve the problem of input saturation. The stability of the closed-loop system with respect to the proposed control scheme is proved by using Lyapunov theory, and the results of numerical simulations are presented to demonstrate the effectiveness of the proposed control strategy.

In this paper a set of engineering calculation methods based on inviscid flow theory for calculating the aerodynamic forces and moments of a representative air-breathing hypersonic vehicle is presented. The viscosity effect is considered to obtain the drag force more accurately by applying temperature reference method. Unlike conventional aircraft, the experimental data of air-breathing hypersonic vehicles (AHVs) are rare to acquire and the common ways to analyze the aerodynamic characteristics of a new designed AHV are using CFD methods. In this way lots of calculation needs to be done at different points of heights and Mach numbers which will take a relatively long time. Therefore the focus of this paper is on developing a method to calculate aerodynamic forces and moments accurately enough and more rapidly than CFD methods. Simulations results demonstrate that the method has a good performance in calculating the aerodynamic coefficients when applied in the phases of the designing and analyzing the characteristics of AHVs.

Traditionally the upper boundary of an entry corridor is determined by quasi-equilibrium gliding condition (QEGC) which is a relatively ‘soft’ constraint, leading to a loosen result. This paper presents an improved generation method in pursue of a stricter entry flight corridor of hypersonic gliding vehicles. Firstly, the path constraints during the entry phase are modeled and the traditional corridor generation method is briefly introduced. Secondly, based on the aforementioned constraints and the dropping trajectories of the vehicles, the innovated method is elaborated. Then, a safety factor is defined. Based on the safety factor, the emergence possibility of a certain velocity can be assessed. With the new generation method and the definition of the safety factor, the features of the entry flight can be better understood.

In recent years due to its high performance and efficiency, scramjet engine (also recognized as supersonic combustion ramjet) has gained remarkable significance in the field of hypersonic air-breathing propulsion. The idea behind this research is to develop a rapid design tool for quick estimation of scramjet configuration for hypersonic range of Mach 5 to Mach 9. This paper includes preliminary design of each scramjet component namely; inlet, isolator, combustor and nozzle. Based on the reliability and accuracy of available scramjet thrust estimation methods, stream thrust analysis method is selected for thrust estimation of designed scramjet engine. The paper focuses on establishing a generic MATLAB code which enables the user to design scramjet geometry at various design point conditions which would later be used for a variety of applications including missile propulsion systems and space access missions. The code is developed by integrating design algorithms of each scramjet component and stream thrust analysis. This code enables user to easily determine the configuration and design parameters of the scramjet based on user defined inputs such as altitude, free-stream Mach (between Mach 5 to Mach 9), exit Mach, inlet height and fuel. While, geometry of scramjet and stream thrust calculation results are obtained as output. Lastly, configuration and design parameters of designed scramjet is compared with existing scramjet engines to conclude and verify the results of the MATLAB code.

Hypersonic vehicles have the characteristics of complex flight environment, dramatic changes of aerodynamic parameters, and high requirements for aircraft robustness. In order to achieve steady state quickly and maintain high accuracy in complex flight environment, fuzzy neural network is added to hypersonic vehicle control. The fast and slow closed loop of the control system adopts fuzzy neural network PID control and traditional PID control respectively. This control strategy not only takes advantage of traditional PID, but also draws on the strong self-learning and adaptive ability of neural network and the online reasoning ability of fuzzy logic. Besides, it overcomes the disadvantage that traditional PID cannot obtain higher accuracy and stronger robustness, and realizes the online adjustment of controller parameters. The attitude simulation results of hypersonic vehicle have achieved better control effect and higher control precision, which verifies the effectiveness of the proposed method.

In this paper, a robust adaptive control scheme is developed for flexible air-breathing hypersonic vehicles (FAHVs) with uncertain parameters and non-minimum phase characteristic. Firstly, the input-output dynamics and internal dynamics of this model are derived. Considering the complicated practical flying environment, a parametric dynamic model of FHAVs is constructed. Then, the ideal internal dynamics(IID), resulting from the non-minimum phase property, are estimated asymptotically via improved system center method. Combined with the sliding mode control theory, a nominal controller is first developed for the nominal FAHVs model. Robust adaptive laws are proposed to update the unknown system parameters. Finally, simulation results demonstrate the effectiveness of the proposed control method.

This paper proposes a Hypersonic Convolutional Neural Network (HCNN) for hypersonic aircraft classification based on a vehicle flight path. The experiments on synthetic data show that HCNN has a high-resolution of identification capability on three types of targets (ballistic missile, hypersonic glide vehicle, hypersonic cruise missile) even in conditions of increased measuring errors, increased time step, and with no preliminary primary data processing. Moreover, one can easily adjust the proposed network for discrimination of an enlarged number of vehicle types.