Design method of adaptive robust sliding mode for integrated guidance and control with multiple constraints

Abstract:

During the terminal guidance stage of striking maneuvering targets, in order to make large caliber naval gun guided projectiles meet multiple constraints of impact angle, line of sight (LOS) angle rate measurement limitation, and actuator control saturation at the same time, an integrated guidance and control (IGC) method was proposed based on adaptive robust control and sliding mode dynamic surface. First, the IGC design model of projectile in vertical plane was constructed. Next, the extended state observer (ESO) was designed to quickly and accurately estimate the LOS angle rate and unknown disturbances, such as target maneuvering. Then, a nonsingular terminal sliding mode was designed based on adaptive exponential reaching law, so that LOS angle tracking error and LOS angle rate could converge to zero in finite time. By combining adaptive robust terms, the sliding mode dynamic surface and virtual control variable were constructed to stabilize the system and reduce the chattering of variable structure terms. Furthermore, by designing an adaptive Nussbaum gain function, the nonlinear problem of control saturation caused by canard deflection limitation was well compensated. On the basis of the Lyapunov stability theory, the finite time convergence of terminal LOS angle tracking error and LOS angle rate as well as the uniform ultimate boundedness of the system were proved. Simulation experiment shows that the proposed design method can make naval gun guided projectiles possess well guidance performance while striking targets with different maneuvering forms.