Summary In this paper, a modified adaptive fast nonsingular terminal sliding mode guidance law is proposed based on the theory of fixed‐time convergence, which applied for intercepting maneuvering targets considering angle constraint. The achieves system stabilization within bounded settling time independent initial conditions and provides no singularity globally rapid convergence property by accelerating rate when close to origin. upper bound can be obtained in advance controller's...

Sliding mode guidance laws based on a conventional terminal sliding guarantees only finite-time convergence, which verifies that the settling time is required to be estimated by selecting appropriate initial launched conditions. However, rapid convergence desired impact angle within uniform bounded finite important in most practical applications. A uniformly finite-time/fixed-time convergent law means (settling) predefined independently conditions, is, closed-loop can priori parameters. In...

The authors describe a reliable and accurate steganalysis method for detecting covert voice-over Internet protocol (VoIP) communication channels. proposed utilises unique sliding window mechanism an improved regular singular (RS) algorithm VoIP steganalysis, which detects the presence of least significant bit embedded streams. With this mechanism, detection moves forward one packet or several packets each time to screen optimum threshold metric is computed by modelling distributions new...

A new model predictive convex programming is proposed in this paper for state and input constrained vehicle guidance design. The method defines a optimization framework considering flexibly designed cost function subject to inequality constraints sensitivity relation between increments corrections. This formulated problem can be solved computationally efficient manner. Simulation studies of nonlinear missile aircraft landing problems demonstrate the effectiveness approach.

A network covert channel is a passage along which information leaks across the in violation of security policy completely undetectable manner. This study reveals our findings analysing principle G.723.1 codec that there are 'unused' bits encoded audio frames, can be used to embed secret messages. novel steganalysis method employs second detection and regression analysis suggested this study. The proposed not only detect hidden message embedded compressed voice over Internet protocol (VoIP)...

This paper addresses the fuzzy-logic-based fixed-time geometric backstepping attitude tracking for rigid-body spacecraft modeled on nonlinear differential manifold three-dimensional special orthogonal group [SO(3)]. The controller is deduced by method. Moreover, an adaptive fuzzy logic system employed to compensate unknown disturbances. almost globally stabilization of closed-loop verified via Lyapunov analysis. Simulation results demonstrate effectiveness proposed controller.

This paper presents a novel three-dimensional autonomous entry guidance for relatively high lift-to-drag ratio vehicles satisfying geographic constraints and other path constraints. The is composed of onboard trajectory planning robust tracking. For planning, longitudinal sub-planner introduced to generate feasible drag-versus-energy profile by using the interpolation between upper boundary lower corridor get desired length. associated magnitude bank angle can be specified drag profile,...

The concept of roll-decoupled course correction fuze with canards can provide a cost-effective solution to improve the delivery accuracy for conventional unguided ammunitions. Due dual-spin configuration and such projectile, basic projectile stability theory should be extended well perceive its behavior motion. seven degree-of-freedom dynamic equations motion are established in fixed-plane frame differential equation complex angle attack is derived by use linear without assumption flat...

This study develops a neural network (NN)‐based multivariable fixed‐time terminal sliding mode control (MFTTSMC) strategy for re‐entry vehicles (RVs) with uncertainties. A coupled MFTTSMC scheme is designed the attitude system on basis of feedback linearisation. saturation function introduced to avoid singularity problem. Adaptive NNs are employed approximate uncertainties in RVs, thus alleviating chattering without sacrificing robustness. The whole closed‐loop proven be bounded and tracking...

Abstract A multiple-vehicles time-coordination guidance technique based on deep learning is suggested to address the cooperative guiding problem of hypersonic gliding vehicle entry phase. dual-parameter bank angle profile used in longitudinal meet requirements time coordination. trajectory database constructed along with a neural network (DNN) structure devised fulfill error criteria, and trained replace conventional prediction approach. Moreover, an extended Kalman filter detect changes...

The paper seeks to study the control system design of a novel unmanned aerial vehicle (UAV). UAV is capable vertical takeoff and landing (VTOL), transition flight cruising via technique direct force control. incremental nonlinear dynamic inversion (INDI) approach adopted for 6-DOF nonaffine UAV. Based on INDI law, method two-layer cascaded optimal allocation proposed handle redundant coupled variables. For weight selection in allocation, strategy proposed. This can adjust objective function...

A novel entry guidance command generation (EGCG) method for hypersonic glide vehicles (HGVs) is proposed in this paper. Apart from the conventional path constraints, terminal and multiple stationary geographic takes into account several threats that HGVs must avoid during process. The are classified covert dynamic threats. information of needs to be detected process, positions even unfixed. piecewise analytical polynomial height-velocity profile used derive an magnitude expression bank angle...

The implementation of advanced guidance laws with bearings-only measurements requires estimation the range information. To improve accuracy and satisfy impact angle constraint, this paper proposes a two-phase optimal law consisting an observing phase attacking phase. In phase, determinant Fisher information matrix is maximized to achieve observability suboptimal solution expressed by leading derived analytically. Then, terminal sliding-mode designed track desired angle. followed integrated...

A two-phased guidance problem with terminal impact angle constraints and seeker’s field-of-view limit is addressed in this paper for a missile against nonmaneuvering incoming target. From the conventional PN without any constraints, it found that satisfying constraint causes more curved trajectory requiring large look angle. To avoid exceeding physical limit, control scheme introduced. The PN-typed law designed each phase specific switching condition of line-of-sight. proposed comprised two...