多约束导引控制一体化的自适应鲁棒滑模设计方法

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

摘要:

在攻击机动目标的末制导段, 为使舰炮制导炮弹能够同时满足攻击角、视线角速率测量受限、执行器控制饱和等多项约束, 基于自适应鲁棒控制与动态面滑模设计了一种导引控制一体化设计方法. 首先, 在纵平面内, 建立了弹体的导引控制一体化设计模型. 然后, 设计扩张状态观测器迅速准确地估计出视线角速率与目标机动等未知干扰. 其次, 运用自适应指数趋近律设计了非奇异终端滑模, 以确保视线角跟踪误差与视线角速率在有限时间内收敛至零. 进而, 结合自适应鲁棒项构造动态面滑模与虚拟控制量用以镇定串级系统并削弱变结构项的抖振. 进一步地, 通过设计自适应Nussbaum增益函数, 较好地补偿了由舵机偏转受限引入的控制饱和非线性问题. 运用Lyapunov稳定性理论严谨地证明了终端视线角跟踪误差、视线角速率的有限时间收敛性, 以及系统的一致最终有界性. 仿真实验表明, 所提出的设计方法能够使舰炮制导炮弹在打击具有不同机动形式的目标时, 均具备较好的导引控制性能.

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.