Adaptive Fixed-Time Cooperative Intercept Guidance Law with Line-Of-Sight Angle Constraint

In this paper, the cooperative interception issues with line-of-sight (LOS) angle constraints through multi-missile system are investigated. To enhance the stability of system, the target maneuvering is regarded as external disturbance, which is estimated by adaptive law and compensated in guidance law. Firstly, transform simultaneous attack issues into consensus problems. Then, a new distributed collaborative guidance law on the LOS direction has been deduced to ensure the impact time of all missiles can be consensus in fixed time. Furthermore, a novel integral sliding mode-based acceleration command in the vertical direction of LOS has been proposed to achieve the desired LOS angle within fixed time. In contrast to the finite-time cooperative guidance law, the convergence time of fixed-time cooperative guidance law is independent of initial states of missiles, which not only quickens the convergence speed, but also relaxes the constraint of the initial states. The validity of the given guidance law is evidenced through the simulated results illustrating a scenario of four missiles intercepting a maneuverable target.