Terminal Phase Guidance Law Against Maneuvering Targets: Adaptive State-dependent Differential Riccati Equation Approach

This paper provides a methodology to address the terminal guidance issue for a highly maneuverable target by formulating the problem as a nonlinear autonomous system with matched term uncertainty. This method involves the utilization of the State-Dependent Differential Riccati Equation (SDDRE) technique to develop an optimal adaptive strategy. Since the SDDRE is vulnerable to variations in the model, the adaptive framework has been devised to address the issue of system uncertainty. The utilization of Laguerre Functions (LFs) is employed to characterize the target acceleration due to its arbitrary shape, while the adaptation law computes the coefficients associated with this representation. The effectiveness of the proposed guidance law has been demonstrated in numerical simulation for various target maneuvers. In addition, the effect of the type and number of basis functions on the estimation had been studied. Ultimately, a sensitivity analysis of design parameters is presented and a comparison is provided between the effectiveness of the proposed guidance law and some of the methods that have been proposed in the literature.