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This paper introduces a novel approach for modeling and optimizing the trajectory and behavior of small solid rocket missiles. The proposed framework integrates a six-degree-of-freedom (6DoF) simulation environment experimentally tuned for accuracy, with a combination of genetic algorithms (GAs) and machine learning (ML) to enhance the performance of the missile path. In the initial phase, a GA is employed to optimize the missile's trajectory for efficient target acquisition, defining key launch parameters such as the ramp angle and lateral maneuver force to minimize positional errors and to ensure effective target engagement. Following trajectory optimization, the derived data are used to train an ML model that predicts setup parameters, significantly reducing computational costs and time. This close integration enables real-time adjustments for acquiring moving targets, thereby improving accuracy and minimizing maneuvering costs. This study also explores the application of fluidic thrust vectoring for small rockets, providing an innovative solution to enhance maneuverability and control, especially at low speeds. The proposed framework was validated using experimental launch data from the Icarus Team. The methodology offers a robust and cost-effective solution for precision targeting and improved maneuverability in aerospace and defense contexts. [ABSTRACT FROM AUTHOR]

Infrared small target detection technology plays a pivotal role in critical military applications, including early warning systems and precision guidance for missiles and other defense mechanisms. Nevertheless, existing traditional methods face several significant challenges, including low background suppression ability, low detection rates, and high false alarm rates when identifying infrared small targets in complex environments. This paper proposes a novel infrared small target detection method based on a transformed Gaussian filter kernel and clustering approach. The method provides improved background suppression and detection accuracy compared to traditional techniques while maintaining simplicity and lower computational costs. In the first step, the infrared image is filtered by a new filter kernel and the results of filtering are normalized. In the second step, an adaptive thresholding method is utilized to determine the pixels in small targets. In the final step, a fuzzy C-mean clustering algorithm is employed to group pixels in the same target, thus yielding the detection results. The results obtained from various real infrared image datasets demonstrate the superiority of the proposed method over traditional approaches. Compared with the traditional method of state of the arts detection method, the detection accuracy of the four sequences is increased by 2.06%, 0.95%, 1.03%, and 1.01%, respectively, and the false alarm rate is reduced, thus providing a more effective and robust solution. [ABSTRACT FROM AUTHOR]

The study of missile guidance systems is a well‐known nonlinear control engineering area of research. To enhance the control performance of a missle guidance system, several technologies have been proposed in existing works. To resolve the weighting matrix selection issue of a linear quadratic Gaussian (LQG) controller for the surface‐to‐air missile guidance control system, this study utilizes the particle swarm optimization (PSO) technique. Selecting the best state (Q) and input (R) weighting matrices is a significant difficulty in the design of the LQG controller for real‐time applications since it affects the controller's performance and optimality. The weighting matrices are often chosen by a trial‐and‐error method that not only complicates the design but also does not yield optimal outcomes. Therefore, in this paper, a PSO method is developed and used in the design of the linear quadratic regulator (LQR) and LQG controllers for the surface‐to‐air missile control system to choose the elements of the Q and R matrices in the best possible way. Finally, a comparative analysis between the designed controllers was presented. The results shows that a good performance was achieved by using the proposed PSO‐tuned design process. The LQG and LQR are designed by manually adjusting the weighting matrices and utilizing an intelligent procedure, PSO algorithm which achieved optimal results. Further results indicate that the designed controllers, the PSO tuned LQR and LQG achieved a better performance over the manually adjusted LQR and LQG controllers. [ABSTRACT FROM AUTHOR]

With the advancement of technology in both combat and defensive situations, the requirement of the use of autonomous vehicles which carry payload is increasing. For the different types of targets, missiles are used. The missile guidance system calculates the miss distance and the trajectory dynamics through automated system. Using image processing, multiple types of target can be identifies. The use of image processing in the guiding system to differentiate between the objects may provide the contemporary error correction in the flight path. In this paper, multiple approaches are used for target identification, tracking and control of trajectory dynamics. The approach identifies two targets, a massive missile truck and an airplane. The algorithm successfully identifies target despite colour variances and almost equivalent structural arrangements. Further trajectory estimation of target is done through constant velocity and constant turn models. When utilising motion estimates and detection, real-world success depends on the ability to recognise visual targets. The Type 1 system's main objective is flight path management using the yaw, pitch, and roll axes. A common atmospheric model and a set of equations are used by the missile autopilot system to describe the aircraft. In MATLAB Simulink, a simulated missile attack travelling at 328 m/s is modelled and simulated. In the model, the missile and its intended target came together at 3.5 s. [ABSTRACT FROM AUTHOR]

In this paper, an integrated estimation guidance and control (IEGC) system is designed based on the command filtered backstepping approach for circular field-of-view (FOV) strapdown missiles. The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint. The boundary time-varying integral barrier Lyapunov function (IBLF) is employed in backstepping design to constrain the body line-of-sight (BLOS) in IEGC system to fit a circular FOV. Then, the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters. The generalized extended state observer (GESO) is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy. Furthermore, the command filters are used to solve the "differential expansion" problem during the backstepping design. The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system. Finally, the simulation results validate the integrated system's effectiveness, achieving high accuracy strikes against maneuvering targets. [ABSTRACT FROM AUTHOR]

This paper introduces a novel approach for modeling and optimizing the trajectory and behavior of small solid rocket missiles. The proposed framework integrates a six-degree-of-freedom (6DoF) simulation environment experimentally tuned for accuracy, with a combination of genetic algorithms (GAs) and machine learning (ML) to enhance the performance of the missile path. In the initial phase, a GA is employed to optimize the missile’s trajectory for efficient target acquisition, defining key launch parameters such as the ramp angle and lateral maneuver force to minimize positional errors and to ensure effective target engagement. Following trajectory optimization, the derived data are used to train an ML model that predicts setup parameters, significantly reducing computational costs and time. This close integration enables real-time adjustments for acquiring moving targets, thereby improving accuracy and minimizing maneuvering costs. This study also explores the application of fluidic thrust vectoring for small rockets, providing an innovative solution to enhance maneuverability and control, especially at low speeds. The proposed framework was validated using experimental launch data from the Icarus Team. The methodology offers a robust and cost-effective solution for precision targeting and improved maneuverability in aerospace and defense contexts.

The paper proposes a method that analyses the dynamic damage probability of laser systems to address the shortcomings of the quantitative model for the damage probability of laser systems. Firstly, the far-field energy density distribution model is constructed according to the power spectrum inversion method. Then, the instantaneous on-target spot power density distribution is equivalently portrayed based on the combination of the far-field power density and the missile target characteristics. Next, the instantaneous on-target spot is combined with the tracking and aiming error to obtain the probability distribution of the energy density of the long-period on-target spot. Finally, the temperature probability distribution is obtained by analyzing the relation between the target energy density and the temperature of the inner wall of the warhead. Consequently, the damage probability was calculated. The simulation shows that there is a unique maximum damage probability when the target is flying in a straight line and the laser system strikes the missile sideways. The method can provide support for the shooting timing of high-energy laser systems. [ABSTRACT FROM AUTHOR]

10.3390/math10081212 8 Ibragimov G., Kuchkarova S., Hasim R.M., Pansera B.A. Differential Game for an Infinite System of Two-Block Differential Equations. References 1 Ibragimov G., Kazimirova R., Pansera B.A. Evasion Differential Game of Multiple Pursuers and One Evader for an Infinite System of Binary Differential Equations. The study of differential games has practical applications in the analysis and resolution of conflict issues by the use of differential equations. [Extracted from the article]

V. Procedural Elements When a transaction is notified to the BTI, the investment screening proceeds in two phases: the screening phase and the review phase. Keywords: Vifo Act; Netherlands; Dutch security screening regime; acquisition activities EN Vifo Act Netherlands Dutch security screening regime acquisition activities 174 178 5 10/13/23 20230701 NES 230701 I. Introduction On 1 June 2023, the Dutch Act on security screening of investments, mergers and acquisitions (the I Wet veiligheidstoets investeringen, fusies and overnames i or the Vifo Act) entered into force. Although sector-specific legislation, such as the Telecommunications Act, the Gas Act and the Electricity Act,[1] already contained investment screening regimes, the Dutch government was not able to intervene in transactions in other sectors that may jeopardize national security. The screening phase seems to be aimed at an initial screening of the transaction whereas the review phase likely targets a more in-depth review of the transaction. [Extracted from the article]

With the development and validation of flight control devices, electronic equipment is widely used in current flight vehicles, which results in a series of control signals in the discrete-time domain. However, many mature integrated guidance and control schemes are designed in the continuous-time domain, and some results of them may not be preserved in the discrete-time domain especially for the sliding mode control. To address this issue, a chattering-free discrete-time sliding mode control scheme is proposed for the integrated guidance and control systems of missiles. By applying the Euler's discretization method, an approximated discrete-time model with matched and mismatched disturbances is first derived for integrated guidance and control system. Then, the estimates of the disturbances are obtained by using discrete-time generalized proportion integral observers. Integrating the estimated disturbances into the sliding mode variable, a discrete-time sliding mode controller is established by utilizing a modified chattering-free reaching law. The reachability of quasi-sliding mode band, states boundedness, and output convergence performance are analyzed rigorously. Finally, comparative numerical simulations are conducted to verify the effectiveness of the proposed control scheme in the presence of unknown target maneuvers and parameter uncertainties. [ABSTRACT FROM AUTHOR]

Another of Sebba's omissions is the rather misleading references to Elizabeth Bentley, the Soviet spy who approached the FBI in 1945 to disclose details of her espionage. The dialogue proved Ethel's total involvement, and included boasts that Ethel had swiftly removed a Leica camera and $7,000 from their apartment just before the FBI searched it. It was reasonable to believe that the cat was out of the bag in 1968 when Kim Philby disclosed in his controversial - yet State Committee for Security (KGB)-approved - memoirs, I My Silent War i , that Ethel and Julius Rosenberg had been Soviet spies.[1] At that time, some campaigners who had advocated their innocence threw in the towel, but it was not until the declassification and release of the VENONA texts in 1995 that their sons, Robert and Michael, finally acknowledged that their father had engaged in espionage. [Extracted from the article]

The engagement of target-interceptor is an extremely complicated and nonlinear problem. Most literatures of developed guidance algorithms are hard to work in real-time missile guidance systems because of the complicated design of controllers, restriction in specific condition or excess computing loading. In this paper, the proposed guidance algorithm computes the predicted interception point of target-interceptor and applies particle swarm optimization to optimize the lateral acceleration control commands of missile where the definition of fitness function can guide the missile toward the predicted interception point when the computed fitness value is the minimum. According to the results of simulation experiments, the proposed method has the satisfied target-kill performance to the superior aircraft with high agility. The missile can greatly revise the flight route toward the computed collision course at the initial pursuit stage and the course curve of missile is flatter than the other two guidance laws. Besides, the proposed method can reduce the occurrence of big lateral acceleration control commands acting on the missile to avoid unlocking the evasive target at the terminal stage. As a result, the proposed guidance algorithm based on particle swarm optimization is very effective without using the complicated nonlinear control methods and excess storage burden of computer. It is a simple and feasible missile guidance algorithm due to the advantages of simplicity and effectiveness just like the proportional navigation guidance law but the performance of proposed guidance algorithm is better than proportional navigation guidance law and the other guidance algorithm designed by particle swarm optimization. [ABSTRACT FROM AUTHOR]

An integrated guidance and control (IGC) scheme considering the field-of-view (FOV) constraint is proposed in this paper for hypersonic skid-to-turn (STT) missiles with a strapdown seeker intercepting a high-speed maneuvering target, which is based on the backstepping control (BC), barrier Lyapunov function (BLF), sliding mode control (SMC), dynamic surface control (DSC), and reduced-order extended state observer (ESO). First, a fifth-order strict feedback IGC model considering the rudder delay dynamics is derived, which also considers the drag effect on the axial velocity. Second, the missile guidance control system based on the BC consists of seeker, guidance, angle-of-attack, attitude, and rudder subsystems. The seeker subsystem was designed based on the BLF, and the other four subsystems were designed based on the SMC. The system-lumped disturbances, including unknown target maneuvers, unmodeled parts, perturbations caused by aerodynamic parameter variations, and external disturbances, were estimated and compensated for using the reduced-order ESO. The DSC prevented the "differential explosion" caused by virtual control commands introduced by the BC. Subsequently, the stability of the closed-loop system was strictly proven using the Lyapunov theory, and the boundedness of the FOV angle was strictly derived. Finally, the simulation results demonstrated the effectiveness and robustness of the proposed IGC scheme. [ABSTRACT FROM AUTHOR]

This paper describes the optimization of target categorization tracking and mathematical modelling to control the autopilot in the missile guidance system, which can recognize any type of target using intelligent devices and image processing. A typical inaccuracy in a reliable connection to the flight path can be reduced by using imaging techniques and new cell communication-based fruit fly swarm optimization within the object recognition processes. The suggested approach is able to locate a target among a batch of visual images captured from a camera, despite the inclusion of two targeting artefacts and their nearly similar layout. Furthermore, it has been proposed to not only evaluate movement objects but also track artefacts with consistent rotation speeds and steady speeds. Aside from adjusting the yaw, pitch, and roll axes, a simulation result for auto-pilot regulation has now been used to control a flight path. Using MATLAB and Simulink software, a simulated missile model was created that moves at 328 m/s toward the target and hits it in 3.25 seconds. [ABSTRACT FROM AUTHOR]

Purpose: A laser seeker is an important element in missile guidance and control systems, responsible for target detection and tracking. Its control is, however, a challenging problem due to complex dynamics and various acting disturbances. Hence, the purpose of this study is to propose a systematic design, tuning, analysis and performance verification of a nonlinear active disturbance rejection control (ADRC) algorithm for the specific case of the laser seeker system. Design/methodology/approach: The proposed systematic approach of nonlinear ADRC application to the laser seeker system consists of the following steps. The complex laser seeker control problem is first expressed as a regulation problem. Then, a nonlinear extended state observer (ESO) with varying gains is used to improve the performance of a conventionally used linear ESO (LESO), which enables better control quality in both transient and steady-state periods. In the next step, a systematic observer tuning, based on a detailed analysis of the system disturbances, is proposed. The stability of the overall control system is then verified using a describing function method. Next, the implementation of the NESO-based ADRC solution is realized in a fixed-point format using MATLAB/Simulink and Xilinx System Generator. Finally, the considered laser seeker control system is implemented in discrete form and comprehensively tested through hardware-in-the-loop (HIL) co-simulation. Findings: Through the conducted comparative study of LESO-based and NESO-based ADRC algorithms for the laser seeker system, the advantages of the proposed nonlinear scheme are shown. It is concluded that the NESO-based ADRC scheme for the laser seeker system (with appropriate parameters tuning methodology) provides better control performance in both transient and steady-state periods. The conducted multicriteria study validates the efficacy of the proposed systematic approach of applying nonlinear ADRC to laser seeker systems. Practical implications: In practice, the obtained results imply that the laser seeker system, governed by the studied nonlinear version of the ADRC algorithm, could potentially detect and track targets faster and more accurately than the system based on the common linear ADRC algorithm. In addition, the article presents the step-by-step procedure for the design, field programmable gate array (FPGA) implementation and HIL-based co-simulation of the proposed nonlinear controller, which can be used by control practitioners as one of the last validation stages before experimental tests on a real guidance system. Originality/value: The main contribution of this work is the systematic procedure of applying the ADRC scheme with NESO for the specific case of the laser seeker system. It includes its design, tuning, analysis and performance verification (with simulation and FPGA hardware). The novelty of the work is also the combination and practical realization of known theoretical elements (NESO structure, NESO parameter tuning, ADRC closed-loop stability analysis) in the specific case of the laser seeker system. The results of the conducted applied research increase the current state of the art related to robust control of laser seeker systems working in disturbed and uncertain conditions. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Missile Guidance system needs accurate estimates from Inertial Navigation System (INS) for guiding the vehicle towards the target. In this paper a target point, specified before launch, in a battlefield scenario is considered for a landmark using missile Strap Down Inertial Navigation System (SDINS) aided by Master INS (MINS) placed on a moving platform. Azimuth information of the missile is one of the most critical navigation states for estimation on the moving platform before launching the missile for precise impact. An Adaptive Kalman Filter (AKF) based on the error state model is formulated. The 7-state AKF with 4-measurement forms the core, where the filter gain of the innovation sequence (measurements) is evaluated. This approach of adaptively computing the gain is tested in a laboratory, on a van and in a ship trial, culminating in a successful guided missile launch. Mean and the covariance of the measurement residuals were used in a unique way to compute adaptive gain after the accumulation of initial samples. A Master INS (with advanced Gyros) whose accuracy is much higher than the accuracy of the missile's SDINS is used for velocity matching algorithm before the launch with execution of an S-maneuver for generation of accelerations towards observing the states more appropriately. Estimated error states were used in a feedback mode to get near the true orientation of the Missile's slave INS. Error quaternions are used for this purpose in the feedback and the gains were selected using offline matrix Riccati equation solution in a discrete domain as used in the modern control system. The results were very encouraging with less than 5 arc minutes of error in azimuth. [ABSTRACT FROM AUTHOR]

In the contemporary battlefield where complexity has increased, the enhancement of the role and ability of missiles has become crucial. Thus, missile guidance systems are required to be further developed in a more intelligent and autonomous way to deal with complicated environments. In this paper, we propose novel missile guidance laws using reinforcement learning, which can autonomously avoid obstacles and terrains in complicated environments with limited prior information and even without the need of off-line trajectory or waypoint generation. The proposed guidance laws are focused on two mission scenarios: the first is with planar obstacles, which is used to cope with maritime operations, and the second is with complex terrain, which is used to cope with land operations. We present the detailed design processes for both scenarios, including a neural network architecture, reward function selection, and training method. Simulation results are provided to show the feasibility and effectiveness of the proposed guidance laws and some important aspects are discussed in terms of their advantages and limitations. [ABSTRACT FROM AUTHOR]

In this paper, a fuzzy observer-based tracking control scheme is proposed for a class of strict-feedback uncertain nonlinear system with input saturation. To facilitate the fuzzy logic system (FLS) design, the original uncertain nonlinear system is transformed into an output feedback system firstly. Then, an adaptive state observer is constructed. In order to efficiently tackle the input saturation, an auxiliary system (AS) is introduced. Using the estimated states and AS, the dynamic surface control (DSC) strategy is developed based on backstepping method. Under the DSC scheme, the tracking control problem is reduced to optimal regulation problem of an affine system. Subsequently, an adaptive dynamic programming (ADP) based optimal control scheme is proposed. The stability of the overall system is guaranteed by Lyapunov theory. Finally, guidance simulation is made to confirm the effectiveness of the developed control method.

Automatic navigation system for agricultural vehicles have become a widely used technology in precision agriculture over the last few decades. More and more sophisticated tractor control systems, however, revealed that exact positioning of the actual implement is equally or even more important. Based on literature sources and patent databases, the aim of this review is to introduce implement guidance systems and describe its current application in agricultural implement. Agricultural implement guidance is an essential technology for autonomous vehicle operations. In addition, applications and new technologies associated with navigation sensors on passive and active implement guidance are analyzed. Finally, challenges and future perspectives of agricultural implement systems are summarized and forecasted. This study can enrich the application of automatic navigation sensors on agricultural implements and provide a reference for the application of automatic navigation on more field operations. [ABSTRACT FROM AUTHOR]

This paper proposes a distributed adaptive dynamic programming scheme to investigate the optimal tracking control problem for finite‐horizon non‐linear interconnected systems with constraint inputs under aperiodic sampling. A N‐player nonzero‐sum differential game system is constructed with the presented non‐linear interconnected system and the tracking error system by introducing the augment vectors. To address the problems of constrained‐input and finite‐horizon control, a non‐quadratic utility function and a finite‐horizon cost function are utilized which will arise in the time‐varying Hamilton–Jacobi (HJ) equation. Then, a periodic event‐triggered scheme is designed to realize aperiodic sampling, where the consumption of communication resources is reduced and the Zeno behavior is avoided. Under the designed periodic event‐triggered scheme, the time‐varying HJ equation is almost impossible to get an analytical solution due to its hybrid properties and non‐linearity. Therefore, the critic neural networks are used to estimate the optimal solution of the HJ equation, and the weight update law is constructed to guarantee the uniformly ultimate bounded of approximated errors. Further, the hybrid nonzero‐sum differential game is confirmed to be uniformly ultimate bounded by using the Lyapunov theory. Finally, the obtained distributed PET control strategy is successfully applied to dispose the missile‐target intercepter problem. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper extends the recently developed quasi-spectral model predictive static programming (QS-MPSP) to include state and control path-constraints and yet retain its computational efficiency. This is achieved by (i) formulating the entire problem in the control variables alone by (a) converting the system dynamics to an equivalent algebraic constraint and (b) converting the state constraints to equivalent control constraints, both of which is done by manipulating the system dynamics, (ii) representing the control variables in Quasi-spectral form, which makes the number of free-variables independent of time-grids and (iii) using a computationally efficient optimization algorithm to solve this low-dimensional problem. This generic computationally efficient technique is utilized next as an effective lead angle, and lateral acceleration constrained optimal missile guidance to intercept incoming high-speed ballistic targets with high precision successfully. Both of these constraints, as well as near-zero miss-distance, are of high practical significance for this challenging problem. Extensive three-dimensional simulation studies show the effectiveness of the newly proposed constrained QS-MPSP guidance algorithm. Six degrees-of-freedom simulation studies have also been carried out using autopilot in the loop to validate the results more realistically. [ABSTRACT FROM AUTHOR]

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As one of the main actuators of the missile guidance control system, the steering gear can adjust the actual thrust and the deflection angle of the rudder surface through the closed-loop control system during the missile guidance process. The attitude correction and speed adjustment of the missile during flight can be accomplished by changing the output injection force by the electric steering gear. In this paper, the theoretical analysis of the jet thrust test mechanism was carried out by the unsteady turbulence analysis theory. Through the flow field simulation, the influence of the position of the bearing wall on the position of the recirculation zone of the impinging jet was studied, and the position of the bearing wall was determined, whose pressure value was closest to the true value. In addition, a simplified test system for jet thrust test was designed. The influence of wall position on the pressure value was verified by experiments, and the accuracy of the simulation results was verified. [ABSTRACT FROM AUTHOR]

Surface-Based Air Defence systems are the main actions on the ground means of response in fighting with aerial threats. Effectiveness of response is given by its basic elements as defended area size, type and number of missiles systems or command and control and logistical support. Guiding method means a well-defined law ruling the missile trajectory near the target, depending on target coordinates and motion parameters, to ensure a successful mission. The influence of target routing law on the missile guidance should not be confused with some guidance methods. Therefore, for missile guidance, it is enough to determine (regardless of the guidance method), the target motion equations related only to its coordinate elevation angle, kinematics, azimuth, and weather conditions. [ABSTRACT FROM AUTHOR]

In this study, a novel integrated guidance and control (IGC) algorithm based on an IGC method and the asymmetric barrier Lyapunov function is designed; this algorithm is designed for the interceptor missile which uses a direct-force/aerodynamic-force control scheme. First, by considering the coupling between the pitch and the yaw channels of the interceptor missile, an IGC model of these channels is established, and a time-varying gain extended state observer (TVGESO) is designed to estimate unknown interferences in the model. Second, by considering the system output constraint problem, an asymmetric barrier Lyapunov function and a dynamic surface sliding-mode control method are employed to design the control law of the pitch and yaw channels to obtain the desired control moments. Finally, in light of redundancy in such actuators as aerodynamic rudders and jet devices, a dynamic control allocation algorithm is designed to assign the desired control moments to the actuators. Moreover, the results of simulations show that the IGC algorithm based on the asymmetric barrier Lyapunov function for the interceptor missile allows the outputs to meet the constraints and improves the stability of the control system of the interceptor missile. [ABSTRACT FROM AUTHOR]

The active defense scenario in which the attacker evades from the defender and pursues the target is investigated. In this scenario, the target evades from the attacker, and the defender intercepts the attacker by using the optimal strategies. The evasion and the pursuit boundaries are investigated for the attacker when the three players use the one-to-one optimal guidance laws, which are derived based on differential game theory. It is difficult for the attacker to accomplish the task by using the one-to-one optimal guidance law; thus, a new guidance law is derived. Unlike other papers, in this paper, the accelerations of the target and the defender are unknown to the attacker. The new strategy is derived by linearizing the model along the initial line of sight, and it is obtained based on the open-loop solution form as the closed-loop problem is hard to solve. The results of the guidance performance for the derived guidance law are presented by numerical simulations, and it shows that the attacker can evade the defender and intercept the target successfully by using the proposed strategy. [ABSTRACT FROM AUTHOR]

In this paper, we study the interior ballistic characteristics of rockets or missiles with acceleration less than 10 g during the compressed air ejection process. First, we designed and fabricated a full-size compressed air ejection system, and utilizing different missile mass and initial pressure variables. Then, we established the mathematical model of the interior ballistics of the ejection system using the fourth-order Runge-Kutta scheme to estimate the ejection performance and results of the system. In addition, we independently built a full-scale compressed air ejection system test platform and conducted multi-condition live ejection tests. The results show that the effective travel distance of the missile is greater than 2.5 m and the acceleration is basically less than 10 g. With a certain missile mass, the acceleration peak, velocity peak and displacement of the missile are positively correlated with the initial pressure, and the opposite variable is negatively correlated. The maximum acceleration and velocity values are 10.11 g and 13.5 m/s, respectively, and the minimum values are about 3.5 g and 4 m/s. The variables are the same, the pressure peak at each measuring point in the ejection barrel is bottom > middle > upper, and the amplitude of the pressure drop between middle and bottom gradually decreases. Depending on the appearance time of the pressure point, the maximum pressure attenuation time in the ejection barrel is determined to be 0.838 s, and the minimum is 0.343 s. Comparing the pressure peak points at the bottom, middle and upper with the calculated pressure curve, the attenuation trend of the two is basically the same. Therefore, the research results show that the full-scale compressed air ejection system is effective and practical, and the test results provide data reference for related launches. [ABSTRACT FROM AUTHOR]