Hypersonic Glide Research Articles

Aerodynamic database of the HEXAFLY-INT hypersonic glider

The present paper is devoted to the aerodynamic characterization and analysis of the HEXAFLY-INT hypersonic glider, developed in the frame of an international project co-funded by the European Community and the European Space Agency. This project aims to design, manufacture and flight test an innovative gliding hypersonic vehicle, which is based on the configuration developed in the previous projects LAPCAT I, II (Steelant et al. in 1st International conference on high-speed vehicle science and technology (HiSST), HiSST-2018-3101064, 26–29/11/2018, Moscow, Russia; Steelant in 15th AIAA international space planes and hypersonic systems and technologies conference, AIAA-2008-2578, 28 April–01 May 2008, Dayton, Ohio, USA) and HEXAFLY (Steelant et al. in 21st AIAA international space planes and hypersonic systems and technology conference, AIAA-2017-2393, 6–9 March 2017, Xiamen, China) and other technologies elaborated in ATLLAS I and II (Steelant et al. in 20th AIAA international space planes and hypersonic systems and technologies conference, AIAA-2015-3677, 5–8 July 2015, Glasgow, Scotland, UK; Steelant in 15th AIAA international space planes and hypersonic systems and technologies conference, AIAA-2008-2582, 28 April–01 May 2008, Dayton, Ohio, USA). The flight experiment consists of a self-controlled glider configuration featuring a high aerodynamic efficiency. This flight demonstrator is equipped with an on-board breakthrough sensing and data acquisition system that will provide valuable aero-thermodynamic and thermo-mechanical data. The measured data will serve to validate the design methodologies and demonstrate the technologies that enable hypersonic transportation. The aerodynamic database comprises an extensive set of CFD simulations of increasing level of accuracy, and an experimental test campaign carried out in the TsAGI T-116 wind tunnel.

Multi-objective suborbit/orbit trajectory optimisation for spaceplanes

In this paper, a suborbit to orbit mission profile is analysed for spaceplanes. The proposed mission profile for spaceplanes is currently being considered for multiple earth observation missions and is considered as an extension of the skip re-entry problem which is a highly coupled and nonlinear problem. To solve the problem, we utilise both the Fuzzy Satisfactory Goal Programming (FSGP) method and the Radau Pseudospectral Method (RPM) as the problem includes more than two objective functions conflicting with each other, and needs to be optimised with pre-emptive priorities. A realistic spaceplane model is used with equality and inequality constraints, to demonstrate the feasibility of suborbit-orbit-suborbit manoeuvres through numerical simulations. The simulation results generated by the proposed methodology show that significant propellant savings can be made using multi-objective trajectory optimisation for spaceplanes for future theatre observation missions.

Cool your jets: Some perspective on the hyping of hypersonic weapons

ABSTRACTRussia, China, and the United States are in a race to develop and deploy hypersonic glide weapons. Hypersonic vehicles are defined as moving at a speed greater than five times the speed of sound. The US Defense Department has claimed these weapons will provide revolutionary new capabilities and will present daunting new threats against which there is currently no effective defense. Such claims have been repeated with little skepticism in the public and trade press. Many of the claims made for hypersonic weapons are, however, overstated and much of what they can do could be accomplished more easily and cheaply using better-established technology, typically via the modification of ballistic missile warheads.

Aerodynamic Statistics-Based Trajectory Estimation of Hypersonic Maneuvering Target

Trajectory tracking and estimation of hypersonic glide vehicles (HGVs) is a very challenging issue in the defense systems. Insufficient knowledge about the HGV and inaccurate dynamic models for the accelerating HGV are the main challenges in this regard. In the present study, an integrated nonlinear Markov acceleration model is established to formulate the nonlinear dynamic characteristics of HGVs. Since the aerodynamic accelerations of the HGV are dominant and the corresponding aerodynamic coefficients are unknown, a statistics-based aerodynamic model is proposed. The proposed aerodynamic model is capable of providing primary information of the aerodynamic characteristics even without knowing the configuration of the HGV. Then, considering the maneuver mode of the vehicle, the iterative extended Kalman filter (IEKF) is applied to track the trajectory of the HGV by using the proposed model. Obtained results from the numerical simulation for the equilibrium glide mode and skip maneuver mode indicate that the proposed model can effectively improve the velocity estimation accuracy by about 40%-50% and acceleration estimation accuracy by about 20%-50% in the given examples.

Rapid Aerodynamic Calculation Method for Hypersonic Gliding Vehicle

The accuracy and efficiency are always conflict in the process of aerodynamic shape design, especially for hypersonic gliding vehicle (HGV). In this work, a rapid aerodynamic calculation method for hypersonic gliding vehicle is conducted, including shape parametric modelling, automatic mesh generation and rapid computational fluid dynamics (CFD) method. In details, the aerodynamic shapes of HGV are modelled by multi-section solids, which parameterized by class function/shape function transformation (CST) method and exponential function. Then, the computational meshes are generated automatically in two steps: one is generating surface mesh by Delaunay method, and another is generating volume mesh by adaptive Cartesian method. In order to minor the computational cost, the hypersonic aerodynamic are analysed by combining the Euler equation and the viscosity force. We have tested the accuracy and efficiency of this rapid aerodynamic calculation method in two flight states for a typical HGV. Compared with Navier Stokes (NS) equations, the results shown the errors of axial aerodynamic force are all less than 6%, but time costs are reduced in hundreds of times.

Phased-Array Radar Task Scheduling Method for Hypersonic-Glide Vehicles

The radar task scheduling problem of phased-array radar (PAR) in detecting hypersonic-glide vehicle (HGV) targets has been studied. Based on the hypersonic-glide vehicle motion-model and detection model, a two-stage scheduling strategy was designed. Task scheduling is divided into two stages: prescheduling and formal scheduling. In the prescheduling stage, low-priority tasks beyond the radar resource capacity are sent into delay queues or delete queues in advance. In the formal scheduling stage, the quantization model of scheduling principles and the objective function of task scheduling are designed, and task requests are scheduled in parallel by using the group intelligence algorithm. A particle swarm-annealing algorithm was designed due to its ease of use and global search ability. The simulation results show that the proposed task scheduling method is superior to the traditional scheduling method in terms of the scheduling success rate, time utilization rate, realization value rate, task miss rate and discovery target number.

Rapid entry trajectory planning without segmentation

A new rapid entry trajectory planning algorithm for hypersonic glide vehicles is presented in this paper. Firstly, build a new technique to calculate the boundary of the control variable that satisfy the path and control constraints without using quasi-equilibrium glide condition (QEGC). Secondly the optimal control variable is expressed as function of current state. Then combine two of them by control coordination. Finally, introduce one or two constant parameters to satisfy the final state condition. The approach is tested using the CAV model. This algorithm is efficient and will provide feasible trajectory without reversal of bank angle. It can apply for entire entry process, segmentation and the QEGC is unnecessary.

A globally fixed-time solution of distributed formation control for multiple hypersonic gliding vehicles

This paper investigates the distributed formation control problem for multiple hypersonic gliding vehicles (HGVs) under direct communication topology. Based on a formation flight framework of multiple HGVs, a globally fixed-time formation control scheme is proposed by using the fixed-time stability and the hierarchical control theory. Firstly, a fixed-time consensus law is addressed in the three-dimensional formation flight dynamics to generate the virtual control inputs. In order to design appropriate actual control inputs to track the virtual control commands rapidly and accurately, a composite fixed-time feedback control law is then put forward, where a new fixed-time tracking differentiator is designed to obtain the information on the time derivatives of virtual control inputs. Following, the problem of “explosion of complexity” can be resolved effectively. Finally, the globally fixed-time convergence is achieved in spite of the initial conditions of HGV's states, where the upper bound of the settling time can be estimated in advance by only using the control parameters and the direct communication topology. The desired formation configuration can be established within a prescribed convergence time. Extensive numerical simulations are performed to demonstrate the effectiveness and superiority of the proposed formation control strategy.

Trajectory Estimation of Hypersonic Glide Vehicle Based on Analysis of Aerodynamic Performance

Due to high speed and high maneuverability of hypersonic glide vehicles (HGVs), the state estimation of such targets has always been a research hotspot. In order to improve accuracy of the trajectory estimation, a nonlinear aerodynamic parameter model for target estimation based on aerodynamic performance analysis is proposed. Firstly, the dynamic characteristics of the hypersonic glide vehicle during the hypersonic gliding stage was analyzed. Then, aiming at HTV-2-liked vehicle, the engineering calculation method was used to form the reference aerodynamic model for the target estimation. Secondly, a deviation model described by first-order Markov process was introduced to compensate the uncertainties of the unknown maneuver information from the target. Finally, extended Kalman filter was utilized to estimate the state of the target. The simulation results show that the proposed model is able to improve the accuracy of acceleration estimation for the HTV-2-liked hypersonic gliding vehicles.

A Damped Oscillation Model for Tracking Near Space Hypersonic Gliding Targets

Maneuver models are dedicated to accurate representation of unknown motion pattern. However, for near space hypersonic jump gliding targets of high speed, diverse movement pattern, and mobility, the conventional maneuver models are difficult to describe the complex movement characteristics, and then leading to high and unstable tracking error. In order to solve this problem, a new model is proposed based on the attenuation of oscillation function. The core of the model is to consider the target acceleration as a zero mean random process with attenuation oscillation. With the model, the equations of the maneuvering target are constructed and the system dynamic error of this model was deduced taking Kalman filter as the filtering algorithm. Moreover, the corresponding relations among parameters are discussed, and an adaptive method is proposed for setting parameters appropriately in the situations when a priori information is unknown. In this way, the parameters can be adjusted online through jumping point identification. Theoretical analysis and simulation experiments are conducted to demonstrate the effectiveness of the proposed model. Comparing to commonly used models, it shows lower filtering errors tracking near space hypersonic jump gliding targets. Finally, the rationality and validity of the parameters adaptive method are explained.

3D guidance for hypersonic reentry gliders based on analytical prediction

In order to give full play to the potential of hypersonic gliders to strike a longrange of targets and perform large lateral maneuvering missions, a three-dimensional guidance method is proposed on the basis of analytical predictions. We first construct an entry guidance model for a glider and derive the analytical solution for the trajectory based on Lyapunov's artificial small parameter method. Such an approach ensures high accuracy in the theoretical prediction of flight trajectory. Subsequently, we construct a three-dimensional (3D) flight corridor that satisfies multiple constraints including heat rate, dynamic pressure, overload, angle of attack, and bank angle. Furthermore, the flight profile and bank reversal strategy in the 3D flight corridor model are designed on the basis of the analytical solution of the flight trajectory considering both longitudinal flight range and lateral flight mobility requirements of the glider. In addition, the control commands of the angle of attack and bank angle are generated by tracking the profile of the flight. The method has been tested in three cases of guidance under short-, medium-, and long-range flights. The results show that it provides high prediction accuracy and strong self-adaptive capability for all the test cases. Our proposed method targets the design of a 3D flight profile in a 3D flight corridor. Furthermore, the method considers flight requirements in both the longitudinal and lateral directions, thus maximising the aircraft's ability to reach the target while maintaining high levels of flexibility and self-adaptive capability during the mission.

Asymmetric arms control and strategic stability: Scenarios for limiting hypersonic glide vehicles

ABSTRACTCan arms control incorporate emerging technology? Other articles in this special issue identify potential risks emerging technologies pose to stability and how they are intertwined with international politics. Is there a future for multilateral strategic arms control? This article looks ahead to explore how arms control might reduce those risks but in order to do so we must update concepts of both arms control and strategic stability. Building on Thomas Schelling and Morton Halperin’s seminal study into the relationship between strategic stability and arms control, this article offers an original framework – asymmetric arms control – for incorporating new technologies, which is then used to identify six scenarios for arms control of hypersonic glide vehicles (HGVs). It concludes that arms control can potentially reduce the risks to strategic stability associated with emerging technologies by incorporating dynamism into arms control design. Ultimately, asymmetric arms control can best contribute to strategic stability by crossing domains and reflecting the cross-domain nature of international conflict, and the framework has potential application to emerging technologies beyond HGVs.

Extended deterrence and assurance in an emerging technology environment

ABSTRACT How do emerging technologies impact strategic stability in the international system? I focus on how one aspect of strategic stability, extended deterrence commitments inherent to alliances, may be impacted by the development of new technologies and capabilities. I ask how technological innovations will impact the market deterrence and assurance dynamics in particular. I argue that while technologies may enhance the ability to provide extended deterrence, allies may be less assured by these new capabilities. To test these hypotheses, I explore emerging capabilities in new domains such as drones and hypersonic glide vehicles on international stability.

Dynamics and Control for Hypersonic Gliding Vehicles Equipped with a Moving Mass and RCS

AbstractTo solve the problems of a hypersonic unpowered gliding reentry vehicle controlled by only one actuator, a combination bank-to-turn control mode with a moving mass and nonredundant reaction...

Entry trajectory generation with complex constraints based on three-dimensional acceleration profile

A new entry trajectory generation based on three-dimensional acceleration profile is proposed for hypersonic glide vehicles, meeting range requirement while taking waypoint and no-fly zone constraints into consideration. Firstly, the path constraints, such as maximum dynamic pressure, total overload and peak heating flux at the stagnation-point, are transformed into longitudinal and lateral flight corridors. And the initial lateral and longitudinal sub-profiles are obtained in sequence based on a layered strategy. Secondly, in order to accurately guide the vehicle to reach a target, a method based on Newton's iterative and bisection search is proposed, and the three-dimensional acceleration profile satisfying the mission requirement is quickly obtained. Further, this approach is extended to accommodate the trajectory generation with regarding the waypoint and no-fly zone constraints. Finally, a three-dimensional tracking law is designed to follow the reference trajectory, verifying the feasibility and accuracy of the proposed method.

Flight Parameter Analysis of an Adaptive Controller of a Hypersonic Glider

This paper presents an analysis of the flight parameters and uncertainties that a HiFire 4–like hypersonic glider experiences through a pull up and a bank maneuver along the descent part of a suborbital ballistic trajectory. The paper addresses a number of long-standing challenges of automatic control of hypersonic vehicles that exhibit numerous aerodynamic and structural uncertainties over a wide Mach-altitude flight envelope. A full-state feedback stabilizing controller that is augmented by an adaptive controller is implemented to control the vehicle. Furthermore, the controllers are able to bring the vehicle to the right initial conditions at an altitude of 26 km to start a scramjet, which are at a speed of Mach 6.

Mapped Chebyshev pseudospectral methods for optimal trajectory planning of differentially flat hypersonic vehicle systems

This paper presents a novel trajectory planning algorithm for hypersonic glide vehicles based on differentially flatness theory and mapped Chebyshev pseudospectral method (MCPM). Firstly, the flatness property of a hypersonic glide vehicle dynamics system is extended explicitly by introducing a pseudo control input along the opposite direction of aerodynamics drag. In this way, all the states and controls of the system can be represented by flat outputs and their derivatives, and the trajectory planning problem is formulated into the flat output space with differential constraints entirely eliminated. Secondly, the optimization problem in the flat output space is converted into a nonlinear programming one via the mapped Chebyshev pseudospectral method. The MCPM employs the conformal mapping principle to discretize the flat outputs at the time interval, in terms of which, the closely clustered Chebyshev points near the boundary are stretched and the ill-conditions of the differential matrix is improved. The Barycentric Lagrange interpolation algorithm is then utilized to interpolate the flat output functions, which is seized of better approximation properties than polynomial interpolation. Finally, the transformed nonlinear programming problem are solved by sequence quadratic program technique. The states and controls are then generated by the expressions of the flatness outputs. At the end of this paper, numerical simulations are performed to evaluate the proposed approaches, and comparisons are made with traditional methods. Simulation results demonstrate that the proposed differentially flatness based mapped Chebyshev pseudospectral method possessed better computing efficiency than traditional ones without losing the merits of high precision.

Optimal trajectories and normal load analysis of hypersonic glide vehicles via convex optimization

Hypersonic trajectory optimization has been intensively investigated through different approaches; however, the normal-load-optimal entry problems were barely studied and reported in the literature. Finding the optimal trajectories with maximum or minimum peak normal load is essential to evaluate the maneuverability and structural strength of the vehicle. In this paper, both the maximum and minimum peak-normal-load entry trajectories are explored using convex optimization. Based on the previous work, the maximum-peak-normal-load entry problem is firstly addressed by a Big-M method and a line-search approach. Through successive relaxations, the nonconvex discrete-event optimal control problem associated with maximum-peak-normal-load entry is transformed into a sequence of mixed-integer convex optimization problems. Then, a line-search technique is introduced to improve the convergence of the proposed method. Additionally, a sequential convex programming method is designed to solve the minimum-peak-normal-load entry problem to comprehensively analyze the normal load during the entry flight. There are efficient solvers that can solve each relaxed convex subproblem with a global optimum if the feasible set of the subproblem is nonempty. The convergence and accuracy of the proposed methodologies are demonstrated by numerical simulations, and the feasibility of the converged solutions is discussed based on an entry-corridor approach.

Hypersonic reentry gliding target tracking based on AVSIMM algorithm

Hypersonic reentry gliding target tracking based on AVSIMM algorithm

Improved artificial potential field based lateral entry guidance for waypoints passage and no-fly zones avoidance

In this paper, a novel improved artificial potential field based lateral guidance algorithm for waypoints passage and no-fly zones avoidance is proposed. By introducing the improved attractive potential field and the improved repulsive potential field, the proposed algorithm converts the waypoints passage problem and the no-fly zones avoidance problem into the reference heading angle determination problem. Based on the heading error threshold and heading angle constraints, the reference heading corridor can be obtained in real time, which is adaptively updated during the entry flight according to the waypoint and no-fly zone constraints. Then the bank reversal logic is employed to regulate the sign of the bank angle, control the lateral motion of the vehicle, and steer the vehicle successfully to the desired terminal zone without any collision of the waypoint and no-fly zone constraints. The simulation results for verification and comparison cases show that the proposed algorithm has better adaptability, applicability and robustness than the alternative methods, and it can be successfully applied in lateral entry guidance of hypersonic glide vehicles with waypoint and no-fly zone constraints.