Three-dimensional guidance law with precise control of attack time and constraints on attack angle.

To achieve strikes against maneuvering targets within a specified time window and complete the coordinated strike task in the case of communication disruption, this paper adopts the Fractional Power Extended State Observer (FPESO) to estimate the target's acceleration. In order to adapt to the dynamic changes of the system in complex environments, a nonlinear term is introduced into the traditional PID Sliding Mode Control (PIDSMC), along with an adjustable parameter a, resulting in the design of a new nonlinear PID sliding surface (NPIDSMC). This paper proposes the FPESO-NPIDSMC guidance law. Simulation results show that the FPESO-NPIDSMC guidance law can achieve strikes against maneuvering targets with the expected attack time and attack angle. In the simulations, FPESO can quickly and accurately estimate the enemy's acceleration, thereby reducing the impact of uncertainties on the guidance system. Monte Carlo simulations further validate the superiority of this guidance law in complex combat environments. Under precise attack time and attack angle constraints, the FPESO-NPIDSMC guidance law proposed in this paper can transform the tracking and interception of maneuvering targets into predictive guidance for striking a stationary point, based on accurate ballistic prediction and enemy position estimation. This reduces the need for expensive active and semi-active seekers, thus lowering interception costs. At the same time, by setting specific attack times for multiple missiles, coordinated strikes can be achieved without the need for communication signal transmission, which enhances the robustness of cooperative attacks.