基于观测器的滑模制导律

Observer-Based Sliding-Mode Guidance Law

为考虑拦截导弹控制回路动态,所设计的滑模制导律在实际应用中往往涉及到不可量测的反馈状态变量和不确定性的内部参数等问题。采用自适应控制和观测方法,给出了一种基于观测器的自适应滑模制导律,观测器主要用于实现对系统状态,如视线角速度的高阶导数和有界不确定项,如相对运动速度的高阶导数等的在线估计,从而满足实际情形下的可执行性要求。制导律推导中考虑到了拦截导弹具有一阶机动动态的情形,且该方法也可以推广到具有高阶机动动态下的设计。非线性系统仿真表明,相比于传统的比例导引和滑模制导律,该制导律在足够的机动性能下,不仅可以实现对机动目标的碰撞拦截,且具有较强的机动性能和拦截性能优势,同时仿真结果也表明了所设计的观测器的有效性。

When taking the control loop dynamics of interception missiles into consideration, the designed sliding-mode guidance law often involves some feedback variables which are not directly measurable and some internal parameters that exists uncertainties. Based on adaptive control and estimation techniques, a novel observer-based adaptive sliding-mode guidance law was presented. The observer can realize the on-line estimation of the system states such as higher-order line-of-sight rate derivatives and the uncertainties such as higher-order closing-velocity derivatives for practical implementation. One-order maneuvering dynamics of interception missile was considered in the guidance law derivation and this approach can also easily be extended to the scenarios of high-order maneuvering dynamics. The nonlinear system simulations show that compared with the traditional proportional navigation and sliding-mode guidance law, this guidance law, with an enough maneuvering capability, can not only realize the hit-to-kill of the target, but also has advantages in maneuvering and homing performance. The simulation results also show the effectiveness of the designed observer.