Aiming at the requirements of time consistency and impact angle for loitering munition swarms in cooperative strike missions, this paper first proposes a time-varying desired formation, transforming the guidance problem with multiple constraints into a cooperative tracking problem of the desired formation. To enable the swarm to reach the constrained state and strike the target under the guidance of the desired formation, a virtual leader is set for the swarm, and an intelligent guidance policy based on the Trust Region Policy Optimization (TRPO) algorithm is designed for the virtual leader, which ensures that the virtual leader can hit the target accurately under the impact angle constraint. The time-varying desired formation is composed of the state vectors of each member in the swarm relative to the virtual leader, where the direction of each vector is determined by the expected impact angle, and the modulus of all vectors converges to 0 at the moment when the virtual leader hits the target. The cooperative guidance command proposed for the swarm to track the time-varying desired formation will drive the linear system constituted by the swarm tracking errors to be stable. The results of numerical simulation show that the swarm tracking error always converges during the guidance process, which ensures that the swarm can hit the target at the expected impact angle simultaneously.

To address the challenge of engaging highly protected and maneuverable targets, this paper proposes a policy that employs cruise missile cluster to strike mobile targets. This method is based on a fully cooperative game framework, employing targeted optimization of the Trust Region Policy Optimization (TRPO) algorithm to train guidance policies for cluster members adhering to fully cooperative game rules. To enhance the damage effectiveness of cruise missiles, this paper considers the terminal impact angle constraint, transforming the convergence of the terminal impact angle into the convergence of the line-ofsight angle. This ensures that the velocity direction at the terminal guidance phase aligns with the target-munition line, thereby improving the damage effectiveness of the cruise missiles.

To intercept the maneuvering target at a desired terminal angle, this paper presents a time-varying sliding mode guidance law with consideration of the second-order autopilot dynamics and input saturation. To achieve the finite-time interception and satisfactory overload characteristics, a time-varying sliding mode guidance law is developed, which enables the line-of-sight (LOS) angle error to converge into a small neighborhood of the origin at the interception time. An auxiliary system is constructed to reduce the adverse effect generated from the input saturation. Moreover, with the aid of extended state observers, the proposed guidance law requires no information on the target acceleration and the acceleration derivative of the interceptor. The performance of this guidance law is verified via the numerical simulations.

The problem of a missile attacking maneuvering targets has been considered in this paper.Meanwhile, a new integrated guidance and control (IGC) method for interceptors with the impact angle is constrained has been proposed. Aimed at achieving the convergence in finite-time ,as well as satisfactory input characteristics, this paper presents a time-varying sliding mode control (TVSMC) method, in which a time-base generator function (TBG) is introduced. Then, this IGC scheme is developed based on the TVSMC and back-stepping technique. At each step, the derivative of the virtual signal is approximated by a tracking differentiator (TD). To enhance the system robustness, the fractional power extended state observer (FPESO) is introduced,for estimating the lumped disturbances and the target maneuvering. Based on the Lyapunov tools, the closed-loop system states are proved to converge into tiny regions around the origin state at the interception time. Finally, the IGC law proposed in this paper has been proved to be effective.

Considering the problem of a skid-to-turn (STT) interceptor attacking maneuvering targets in the three-dimensional space, a new integrated guidance and control (IGC) law with the constraints of impact angles and input saturation is developed. To achieve the finite-time convergence and satisfactory input characteristics, a time-varying sliding mode control (TVSMC) method is presented based on a time base generator function. To this end, the IGC scheme is developed based on the TVSMC and the back-stepping. At each step, the derivative of the virtual signal is approximated by a tracking differentiator. Meanwhile, an auxiliary compensation system is designed to reduce the adverse effect raised from the saturation error. Moreover, the modeling uncertainties and disturbances are attenuated effectively by using fractional power extended state observers to estimate them. The closed-loop system states are proved to be uniformly ultimately bounded and the controlled states are proved to converge into small neighborhoods of the origin at the interception time. Finally, the performance of the presented IGC law is verified through numerical simulations.