Three-Dimensional Adaptive Variable-Power Sliding-Mode Multi-Vehicle Cooperative Guidance Law

To address the problem of cooperative multi-vehicle operations targeting critical objectives in three-dimensional space, this paper proposes a variable-power adaptive fast sliding-mode guidance law. First, a dynamic vehicle–target model is established in three-dimensional space by using the projection of the horizontal vehicle–target plane to determine the reference plane. The guidance law design is projected onto the reference plane based on the average consensus convergence control method. This not only drives the estimated deviations to zero to achieve time consistency but also ensures that the estimated time-to-go converges to the actual time-to-go. Additionally, an adaptive input compensation component is designed in the vertical line-of-sight (LOS) direction, driving the aspect angle to converge to zero before the final point is reached. Furthermore, in the vertical reference plane direction, an adaptive variable-power sliding-mode control method is designed based on the traditional sliding-mode control scheme, in which the corresponding power exponent is selected according to the variation exhibited by the sliding-mode values. On the one hand, higher power levels can result in faster convergence; on the other hand, lower power levels can be associated with better stability. Compared with the traditional sliding-mode control technique, the proposed method achieves guaranteed stable convergence at the end of the control process, with a 49% improvement in convergence efficiency. Finally, simulations verify the designed three-dimensional guidance law, demonstrating that it features fast convergence, high stability, and high precision.