With the increasing complexity and frequency of interactions among a large number of heterogeneous nodes within a combat system of systems (SoS), evaluating the capability of the SoS to withstand external attacks and interferences has become an increasingly challenging and urgent issue. However, the complexity of a combat SoS often brings about difficulties in quantitative analysis. This paper proposes a method to assess the resilience of a combat SoS. Firstly, a network model of a combat SoS is constructed, taking into account multi-functional composite nodes. Secondly, the combat capability model of the combat SoS is built based on the capabilities of the kill chains and kill networks. Lastly, an approach is proposed to calculate the combat capability of the system based on the network’s two-terminal connectivity. Moreover, based on the SoS’s combat capability, the resilience is analyzed from the dimensions of anti-destruction, survival, and recovery. The simulation experiments show that, compared to other methods, the method in this paper for calculating the combat capability of the combat SoS does not depend on the number of kill chains and aligns with the combat processes and actual patterns. Additionally, the resilience measurement method can effectively analyze its capability to cope with external interferences.

Existing Decision-Making Trial and Evaluation Laboratory (DEMATEL) methods are mostly suitable for simple systems with fewer factors, and lack effective integration of expert knowledge and experience from large-scale group populations, resulting in a potential compromise of the quality of the initial direct relation (IDR) matrix. To make DEMATEL better suited for the identification of critical factors in complex systems, this paper proposes a hierarchical DEMATEL method for large-scale group decision-making. Considering the limitations of expert knowledge and experience, a method based on expert consistency network for constructing the expert weight matrix is designed. The expert consistency network is constructed for different elements, and the weights of experts in different elements are determined using the clustering coefficient. Following the principles of the classic DEMATEL method, the steps for identifying key elements in complex systems using the large-scale group-hierarchical DEMATEL method are summarized. To objectively test the effectiveness and superiority of the decision algorithm, the robustness of the algorithm is analyzed in an interference environment. Finally, the superiority of the proposed method and algorithm is verified through a case study, which demonstrating that the proposed decision-making method is suitable for group decision-making in complex systems, with high algorithm stability and low algorithm deviation.

The cooperative interception trajectories generation of multiple interceptors to hypersonic targets is studied. First, to solve the problem of on-line trajectory generation of the single interceptor, a generation method based on neighborhood optimal control is adopted. Then, when intercepting the strong maneuvering targets, the single interceptor is insufficient in maneuverability, therefore, an on-line multiple trajectories generation algorithm is proposed, which uses the multiple interceptors intercept area (IIA) to cover the target's predicted intercept area (PIA) cooperatively. Through optimizing the interceptors' zero control terminal location, the trajectories are generated on-line by using the neighborhood optimal control method, these trajectories could make the IIA maximally cover the PIA. The simulation results show that the proposed method can greatly improve the interception probability, which provides a reference for the collaborative interception of multiple interceptors.

The high speed gliding aircraft has fast flight speed, posing high interception difficulty. This paper proposes a multi-stage interception scheme and presents a trajectory optimization method based on the hp adaptive Radau pseudospectral method (hp-ARPM) for interceptors. This method can effectively meet various constraints such as heat flux density and dynamic pressure, effectively solving the trajectory optimization problem of interceptors. Firstly, the flight process of interceptors is divided into initial boost stage, midcourse guidance stage, and terminal guidance stage to meet the requirements for long range interception of high-speed gliding aircraft. Taking into account that the initial boost stage is strongly affected by aerodynamic forces while the midcourse guidance stage is weakly affected, separated motion models are established for the initial boost stage and the midcourse guidance stage to more precisely describe the flight behavior of interceptors. Secondly, a multi-stage, multi-constraint nonlinear trajectory optimization model for interceptors is constructed, with connection constraints, process constraints, and optimization performance indicators established for different flight stages. Then, by using the hp-ARPM to transform the optimal control problem into a nonlinear programming problem (NLP), the optimal control solutions for the boost stage and midcourse guidance stage of interceptors are directly obtained by solving the NLP problem. The hp-ARPM method can adaptively adjust the number of nodes, improving optimization accuracy and computational efficiency. Simulation comparison experiments demonstrate that the multi-stage interception scheme proposed in this paper is feasible, and the hp-ARPM shows superior performance indicators compared to the Gauss pseudo-spectral method (GPM).

The hybrid unmanned aerial vehicle combines the vertical take-off and landing and hover abilities of rotary-wing UAVs with the high-speed cruise and long-endurance capabilities of fixed-wing UAVs, expanding the flight envelope and application areas. The designed controller must handle the highly nonlinear dynamics and variable actuators resulting from this combination. Furthermore, the performance of the controller is also influenced by uncertainties in model parameters and external disturbances. To address these issues, a unified robust disturbance rejection control based on fixed-time stability theory is proposed for attitude control. A fixed-time disturbance observer is utilized to estimate composite disturbances without some strict assumptions. Based on this observer, a nonsingular chattering-free fixed-time integral sliding mode control law is introduced to ensure that tracking errors converge to the origin within a fixed time. In addition, an optimized control allocator based on the weighted least squares method is designed to handle the overactuation of a dual-system hybrid UAV. Finally, numerical simulations and hardware-in-the-loop experiments under different flight modes and disturbance conditions are carried out, and compared with nonlinear dynamic inverse and the nonsingular terminal sliding mode control based on a finite-time observer, the developed controller enhances attitude angle tracking accuracy and disturbance rejection performance.

During the interception of a high-speed gliding vehicle (HGV), the predicted intercept point (PIP) is updated many times, so the interceptor must continuously adjust its trajectory. In this paper, we propose an online guidance correction algorithm for the interceptor, which can effectively meet the position constraints and energy management of the guidance process. Firstly, we simplify the interceptor’s maneuvering problem to a two-body orbital transfer problem. The Lambert orbit transfer method is used to enable the interceptor to maneuver towards the target’s PIP. Secondly, by comparing the target’s high probability existence area (THPEA) with the interceptor-interceptable area (IIA), the engine start threshold is set in stages to avoid frequent redundancy maneuvers caused by frequent engine starting during missile correction. This approach achieves energy management. Simulation results show that our midcourse guidance strategy is effective.