Showing papers on "Missile published in 2022"

Impact-Angle-Constrained Cooperative Guidance for Salvo Attack

Abstract: This paper proposes distributed cooperative guidance laws for multiple missiles with constant speeds to achieve impact-angle-constrained salvo attack against a stationary target in both two-dimensional (2D) and three-dimensional (3D) scenarios. First, the 2D cooperative guidance law is derived based on an optimal impact angle control guidance (IACG) law, which is augmented by a cooperative guidance term to ensure consensus of times-to-go in a fixed time before interception. To avoid singularity, an auxiliary function with three candidates is introduced into the cooperative guidance term. Then, coplanar cooperative guidance (CCG) and planar pursuit guidance (PPG) commands are, respectively, derived to construct the 3D cooperative guidance law. The CCG command is based on the coplanar assumption and the 2D cooperative guidance law, whereas the PPG command drives the velocity, line of sight (LOS), and desired impact vectors onto one engagement plane by geometric operations of vectors. Unlike existing 3D cooperative guidance laws, the proposed one does not require missile speed adjustment for salvo attack. The fixed-time stability and effectiveness of the proposed guidance laws are theoretically analyzed. The criteria for selecting all guidance parameters are provided to facilitate the guidance design. Finally, numerical simulations are conducted to support the analytical findings.

Fixed-Time Terminal Angle-Constrained Cooperative Guidance Law Against Maneuvering Target

Abstract: In this article, fixed-time cooperative guidance laws are designed for multiple missiles to simultaneously attack a maneuvering target at desired terminal angles. The 3-D guidance commands consist of tangential acceleration along line-of-sight (LOS) direction to achieve a salvo attack and normal acceleration perpendicular to the LOS direction to realize a terminal angle-constrained interception. First, the tangential acceleration is derived from a distributed cooperative protocol to guarantee the fixed-time consensus of impact times for multiple missiles. Second, based on the integral sliding manifold and fixed-time reaching law, the normal acceleration is developed for each missile to converge the LOS angle to the desired value within a fixed time. In particular, the unknown target acceleration components are estimated by fixed-time observers and compensated in the guidance commands. The fixed-time stability of the proposed cooperative guidance law is rigorously proved and the explicit estimate for the convergence time is theoretically provided. Then, the proposed methods are utilized to realize the cooperative mission in the planar guidance scenario. Finally, the effectiveness and advantages of the proposed cooperative guidance laws are demonstrated through numerical simulations with comparative studies.

Multichannel Clutter Modeling, Analysis, and Suppression for Missile-Borne Radar Systems

Abstract: When a missile-borne radar system works in downward-looking surveillance mode, the broadened ground clutter signal in virtue of platform high-speed motion will be received by the radar receiver, which will cause difficulty in moving target detection and attacking. Unlike airborne and spaceborne platforms, a missile-borne platform exhibits some unique motion characteristics, such as diving, spinning, and coning, causing the clutter space–time distribution property significantly different from those of airborne and spaceborne radar platforms. In addition, the forward target striking requirements make the missile-borne clutter space–time spectrum further exhibit the severe range-dependent property. To deal with these issues, accurate motion modeling of a missile-borne radar platform is first carried out in this article, where the complex platform motions including forward-looking diving, spinning, and coning are considered. Then, the autocorrelation processing combined with iterative adaptive approach is applied to estimate the clutter angle-Doppler center frequencies, so as to effectively realize the clutter nonstationary compensation along spatial and temporal directions. Finally, a time-domain sliding window-based subspace projection method is proposed to achieve the robust clutter suppression. Both simulation and real-measured radar data processing results are presented to validate the effectiveness and feasibility of the proposed algorithm.

Cooperative guidance law for intercepting a hypersonic target with impact angle constraint

Abstract: Abstract The cooperative guidance problem of multiple inferior missiles intercepting a hypersonic target with the specific impact angle constraint in the two-dimensional plane is addressed in this paper, taking into consideration variations in a missile’s speed. The guidance law is designed with two subsystems: the direction of line-of-sight (LOS) and the direction of normal to LOS. In the direction of LOS, by applying the algebraic graph theory and the consensus theory, the guidance command is designed to make the system convergent in a finite time to satisfy the goal of cooperative interception. In the direction of normal to LOS, the impact angle is constrained to transform into the LOS angle at the time of interception. In view of the difficulty of measuring unknown target acceleration information in real scenarios, the guidance command is designed by utilising a super-twisting algorithm based on a nonsingular fast-terminal sliding mode (NFTSM) surface. Numerical simulation results manifest that the proposed guidance law performs efficiently and the guidance commands are free of chattering. In addition, the overall performance of this guidance law is assessed with Monte Carlo runs in the presence of measurement errors. The simulation results demonstrate that the robustness can be guaranteed, and that overall efficiency and accuracy in intercepting the hypersonic target are achieved.

Radiative Transmission and Absorption Within the Thermal Protection System of Atmospheric Entry Spacecraft

Abstract: Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.

Multiple missiles fixed-time cooperative guidance without measuring radial velocity for maneuvering targets interception

Abstract: For multiple missile simultaneously intercepting a maneuvering target, under the directed communication topologies between missiles, this paper designs a fixed-time cooperative guidance law based on three-dimensional guidance system. Furthermore, the radial velocity measurements are not required for the designed method. First, we construct the cooperative guidance model by using the three-dimensional missile-target intercepting geometry. Then, based on the fixed-time differentiator and the bi-limit homogeneity theory, a consensus protocol is designed in line-of-sight (LOS) direction, which can ensure missile's impact time achieve fixed-time consensus. Next, in normal direction of LOS, two continuous adaptive fixed-time guidance laws are designed to guarantee LOS angular rates achieve fixed-time convergence. Finally, the excellent performance of the designed method is validated by simulation results.

Learning-Based Policy Optimization for Adversarial Missile-Target Assignment

Abstract: The missile-target assignment (MTA) is a typical weapon-target assignment problem in Command and Control of modern warfare. Despite the significance of the problem, traditional algorithms still lack efficiency, solution quality, and practicability in the adversarial environment. In this article, we propose a data-driven policy optimization with deep reinforcement learning (PODRL) for the adversarial MTA. We design a comprehensive reward function to motivate the optimization of assignment policy. As such, the learned policy can implicitly model the penetration of missiles under an adversarial environment in a data-driven way. We also present a fair sample strategy to improve the sample efficiency and accelerate the policy optimization. Experimental results show that PODRL can adaptively generate satisfactory solutions in both small-scale and large-scale instances. Furthermore, we evaluate the effectiveness of PODRL in a multiobjective scenario. The result demonstrates that a well-optimized policy can achieve high-quality allocation and demand forecast of the missile resources simultaneously.

Fixed-time ESO based fixed-time integral terminal sliding mode controller design for a missile

Abstract: This paper studies a novel fixed-time extended state observer based fixed-time integral terminal sliding mode controller for partial integrated guidance and control design. Firstly, a class of arbitrary-order systems with fixed-time stability is proposed by utilizing homogeneous approach, whose upper bound of convergence time is given. Then, an arbitrary-order fixed-time integral terminal sliding mode control is designed based on the proposed arbitrary-order fixed-time stable system, which avoids the singular problem. Subsequently, this paper constructs a new fixed-time extended state observer to further actively compensate for the disturbance caused by unknown target acceleration. Finally, numerical simulations show the effectiveness of the proposed controller.

Online intelligent maneuvering penetration methods of missile with respect to unknown intercepting strategies based on reinforcement learning

Abstract: This paper considers the maneuvering penetration methods of missile which do not know the intercepting strategies of the interceptor beforehand. Based on reinforcement learning, the online intelligent maneuvering penetration methods of missile are derived. When the missile is locked by the interceptor, in terms of the tracking characteristics of the interceptor, the missile carries out tentative maneuvers which lead to the interceptor makes the responses respectively, in the light of the information on interceptor responses which can be gathered by the missile-borne detectors, online game confrontation learning is employed to increase the miss distance of the interceptor in guidance blind area by reinforcement learning algorithm, the results of which are used to generate maneuvering strategies that make the missile to achieve the successful penetration. The simulation results show that, compared with no maneuvering methods or random maneuvering methods, the methods proposed not only present higher probability of successful penetration, but also need less overload and lower command switching frequency. Moreover, the effectiveness of this maneuvering penetration methods can be realized under the condition of limited number of training.

Intelligent Guidance and Control Methods for Missile Swarm

Abstract: High-speed unmanned aerial vehicles (UAVs) are more and more widely used in both military and civil fields at present, especially the missile swarm attack, and will play an irreplaceable key role in the future war as a special combat mode. This study summarizes the guidance and control methods of missile swarm attack operation. First, the traditional design ideas of the guidance and control system are introduced; then, the typical swarm attack guidance and control methods are analyzed by taking their respective characteristics into considering, and the limitations of the traditional design methods are given. On this basis, the study focuses on the advantages of intelligent integrated guidance and control design over traditional design ideas, summarizes the commonly used integrated guidance and control design methods and their applications, and explores the cooperative attack strategy of missile swarm suitable for the integrated guidance and control system. Finally, the challenges of missile swarm guidance and control are described, and the problems worthy of further research in the future are prospected. Summarizing the guidance and control methods of missile will contribute to the innovative research in this field, so as to promote the rapid development of unmanned swarm attack technology.

Comparisons of Predicted and Measured Aerodynamic Characteristics of the DLR LK6E2 Missile Airframe (Scale Resolving)

Abstract: Time-accurate, turbulence scale resolving simulations of a transonic missile at high incidence and roll angle were performed and compared to simulations using standard Reynolds-Averaged Navier-Stokes turbulence models. The scale resolving simulations showed improved prediction of the total roll moment observed in wind tunnel tests compared to the RANS simulations, but still did not accurately predict the trend in roll moment with incidence angle in the range 15.0°≤σ≤17.5°. The scale resolving simulations predicted less turbulence energy in the vortex structures and larger separation regions over the wings. Spectral analysis of the roll moment signal showed dominant frequency modes consistent with a leading-edge vortex breakdown over two wings.

Adaptable Deployable Entry and Placement Technology Sounding Rocket One Modeling and Reconstruction

Abstract: Sounding Rocket One (SR-1), the first flight test of the Adaptable Deployable Entry and Placement Technology (ADEPT), was performed on September 12, 2018. ADEPT is a deployable aeroshell that is stowed for launch and deployed before atmospheric flight to increase the drag area of the spacecraft. The main objectives of the SR-1 flight test were to demonstrate that the ADEPT vehicle deploys exo-atmospherically and to characterize the stability of the vehicle during atmospheric flight. The SR-1 test vehicle was a 0.7-m-diam, 70°-half-angle faceted sphere-cone and was the primary payload on an UP Aerospace Spaceloft launch vehicle from the White Sands Missile Range. ADEPT successfully separated from the spent booster in its stowed configuration, opened above 100 km altitude, and landed in the deployed configuration within White Sands Missile Range. ADEPT was able to reach peak Mach number of 3.1 and was able to show angle-of-attack stability through Mach 0.8, which was the objective of the mission. The aerodynamics and flight mechanics of the vehicle were modeled preflight for performance and range safety predictions. After the flight, the on-board instrumentation was used to reconstruct the flight performance. This paper describes the predictions and postflight reconstruction, and how the predictions compared with the flight data.

Varying-Gain Proportional Navigation Guidance for Precise Impact Time Control

Abstract: This paper proposes a varying-gain proportional navigation guidance (PNG) law that can serve as the baseline for precise control of impact time. First, a varying-gain PNG law is developed by an inverse design strategy from the explicit time-to-go estimation of the conventional PNG law, which leads to high control efficiency and accurate time-to-go prediction. Next, to show its potential significance, the varying-gain PNG law is augmented with a biased feedback command to obtain an impact time control guidance (ITCG) law. As a step forward in more practical applications considering missile speed variation induced by thrust, drag, and gravity, another ITCG law is derived from an efficient time-to-go prediction method by taking the exact trajectory-to-go as the independent variable. Further, the varying-gain PNG law and the planar ITCG laws are extended to the three-dimensional guidance scenario by steering the missile to fly on an engagement plane. Compared with similar existing results, the proposed ITCG laws based on the varying-gain PNG law do not involve any linearized approximations in the derivation, and thus possess higher impact precision, wider feasible region, and less energy consumption. Finally, several numerical simulations are performed to support the analytical findings.

Maneuvering penetration strategies of ballistic missiles based on deep reinforcement learning

Abstract: In this paper, a ballistic missile terminal penetration scenario is studied, which contains three participants: target, missile, and defender. The ballistic missile attempts to hit the target while evading the defender. A maneuvering penetration guidance strategy that balances both the guidance accuracy and penetration capability is proposed through deep reinforcement learning. Reward shaping and random initialization are applied to improve training speed and generalization, respectively. The proposed strategy is developed based on the twin delayed deep deterministic policy gradient algorithm. It directly maps observations to actions and is an end-to-end guidance scheme that does not require an accurate model. The simulation results show that the proposed strategy has higher penetration probabilities than conventional strategies for different initial heading errors and even for defenders with different guidance laws, which indicates its good robustness and generalization. For different initial heading errors, it has learned different maneuvering modes and has certain intelligence. In addition, it is computationally small, does not consume much memory, and can be easily applied on modern flight computers.

Safety assessment of large-scale all steel LNG storage tanks under wind-borne missile impact

Abstract: Regarding the disastrous consequences, the large-scale all steel liquefied natural gas (LAS-LNG) storage tank is regulated to be designed to resist the potential impact of wind-borne missiles. This paper aims to study the dynamic response and damage of LAS-LNG storage tanks subjected to the accidental typical wind-borne missile impact. Firstly, six Schedule 40 pipe and flange assembly missiles weigh 36.5 kg were designed according to the specifications of BS 7777 and RG 1.76. Based on the 300 mm-caliber single-stage gas gun, the impact test was conducted with a missile striking velocity of 50 m/s. The local deformation and global response of media-filled steel tanks were assessed experimentally. Then, the commercial finite element (FE) program LS-DYNA was utilized to perform the numerical simulations considering the fluid–structure interactions. The adopted numerical algorithm, constitutive models and the corresponding parameters were validated by comparing with the test data. Finally, based on the validated finite element analyses approach, regarding the design-basis wind-borne missiles specified by the regulatory guide of U.S. Nuclear Regulatory Commission and American Nuclear Society, i.e., RG 1.76, RG 1.221 and ANSI/ANS-2.3-2011, the damage levels of the prototype Chinese Yuhuan LAS-LNG storage tank under wind-borne missile impact were assessed numerically. It indicates that the filled media in the tank would provide additional resistance to the missile impact, the present three design-basis wind-borne missiles could bring certain damage to the outer tank of the Yuhuan LNG storage, but the safety of the inner tank can be guaranteed.

Impact time and angle constrained guidance via range‐based line‐of‐sight shaping

Abstract: In this article, impact time and angle constrained guidance law is proposed using a range‐based line‐of‐sight (LOS) shaping strategy. The relative motion of missile and target is described in a polar coordinate, where the LOS angle can be shaped as a polynomial function of range‐to‐go. The order of the polynomial function is selected according to the number of constraints. Coefficients of the polynomial function are determined by the boundary conditions and solved through a simple integral equation, which facilitates the onboard implementation. Guidance command is designed in a state feedback form to track the shaped trajectory. The proposed guidance law shows some advantages over several similar polynomial shaping based guidance laws. Multiple simulation studies demonstrate the effectiveness of the proposed guidance law.

GPU-Accelerated PD-IPM for Real-Time Model Predictive Control in Integrated Missile Guidance and Control Systems

Abstract: This paper addresses the problem of real-time model predictive control (MPC) in the integrated guidance and control (IGC) of missile systems. When the primal-dual interior point method (PD-IPM), which is a convex optimization method, is used as an optimization solution for the MPC, the real-time performance of PD-IPM degenerates due to the elevated computation time in checking the Karush–Kuhn–Tucker (KKT) conditions in PD-IPM. This paper proposes a graphics processing unit (GPU)-based method to parallelize and accelerate PD-IPM for real-time MPC. The real-time performance of the proposed method was tested and analyzed on a widely-used embedded system. The comparison results with the conventional PD-IPM and other methods showed that the proposed method improved the real-time performance by reducing the computation time significantly.