考虑自动驾驶仪动态特性和攻击角约束的鲁棒末制导律

摘要

针对制导弹箭打击机动目标时带攻击角约束的末制导问题,考虑自动驾驶仪动态特性以及目标机动不确定性对制导过程的影响,结合积分滑模与动态面控制方法,设计了一种新型鲁棒末制导律.自动驾驶仪的动态特性以含扰动的2阶动力学模型来表征,目标机动引起的模型不确定性以光滑非线性扰动观测器来估计.滑模面取视线角速率与视线角偏差的组合形式,且引入剩余飞行时间,以使制导弹箭在整个末制导过程中过载性能良好.依据李雅普诺夫稳定性理论证明了闭环系统中视线角速率与视线角偏差均最终一致有界任意小.通过数值仿真与弹道成型制导律及非奇异滑模制导律进行了对比,验证了该末制导律的有效性与优越性.%A novel robust impact-angle-constrained guidance law with autopilot lag is proposed based on integral sliding mode and dynamic surface control for guided projectiles.The inner-loop autopilot is characterized by an uncertain second-order dynamics.The sliding mode variable is defined as a combination of the line-of-sight (LOS) rate and the LOS angle error with time-to-go in order to realize the guidance strategy and achieve a good acceleration performance during interception.The smooth nonlinear disturbance observer is adopted to obtain the model discrepancies from target maneuver and the speed variation of target and interceptor.The stability of LOS rate and the LOS angular deviation is proved in the sense of the uniform boundedness and ultimate boundedness.Simulated results show the effectiveness and superiority of the proposed robust terminal guidance law compared to the trajectory shaping guidance law and the nonsingular terminal guidance law.