Cooperative Guidance for Simultaneous Interception Using Multiple Entangled Sliding Surfaces

A cooperative guidance strategy is developed to enable multiple pursuers to intercept a target simultaneously. The guidance strategy works to minimize the time-to-go difference between neighboring pursuers while still keeping them on track for interception. The guidance law is derived using sliding mode control, with one sliding surface for every pair of neighboring pursuers to remove time-to-go difference and one global sliding surface to make sure at least one pursuer is heading toward the target, guaranteeing the others’ interception as well. A time-to-go approximation scheme for a stationary target is used during the derivation. In addition, the guidance law is expanded to a moving target using a predicted interception point approximation scheme. A two-dimensional nonlinear simulation of the relative kinematics is run for cases of both two pursuers and more, as well as a moving target, in which the guidance law is shown to successfully cause simultaneous interception among multiple pursuers starting from different initial conditions. The guidance law is compared to different guidance laws, bringing simultaneous interception for a case where a disturbance is entered into the system in the middle of the encounter, showing the flexibility of the derived guidance law to deal with such a disturbance.