Time-varying Terminal Sliding Mode Based on Salvo Attack Cooperative Guidance Law for Unknown Uncertainty Upper Bounds

In this paper, a new time-varying terminal sliding mode with unknown uncertainty bounds is designed to make multiple missiles-attack against the maneuvering target simultaneously. The new method in this paper can guarantee accurate time-to-go by distributed cooperation. Then, a new cooperative guidance law is designed for the nonlinear system based on the known uncertainty bound. Furthermore, it is extended to unknown uncertainty bound using the disturbance observer and the composite cooperative guidance law. The desired salvo attack time is achieved by selecting the parameter variables of sliding model and the adjacency matrix in the end. Numerical simulations with the comparisons demonstrate the effectiveness and the superiority of the proposed method.