基于模糊变系数策略的迎击拦截变结构制导律设计

Design of Variable Structure Guidance Law for Head-on Interception Based on Variable Coefficient Strategy

迎击拦截是拦截问题中常见的一种制导方式。为提高拦截器的末制导精度,基于变结构控制设计零化视线角速率的变结构制导律是一种典型方法。对高速目标的迎击拦截出现相对速度过大,目标机动能力引起的导引初段需用过载过大的问题,应用模糊控制设计制导律的导航项及变结构项系数随剩余导引时间变化的策略以延长系统进入滑模面的时间,使系统进入滑模面的同时有效减小末制导初段的控制量。建模及仿真结果显示,该制导律在使视线角速率收敛的同时显著地减小了导引初段的需用过载,验证了该方法的有效性及对传统比例导引律的优越性。

Head-on interception is a common guidance method for interception problem. The adaptive variable structure guidance law guiding the line-of-sight angular rate to converge to zero is available to im- prove the guidance precision. However, the variable structure guidance law leads to large required accel- eration of interceptor before the line-of-sight angular rate converges to zero, especially in a situation where the target has strong maneuverability as well as high velocity. A strategy making the coefficients of the guidance law vary according to a typical rule via fuzzy control is proposed. Smaller guidance coefficients are selected at the beginning of terminal guidance. Therefore, the guidance command is reduced and a smaller acceleration of interceptor is incurred. As the coefficients grow to the fixed and desired values, the line-of-sight angular rate converges to zero rapidly so that the stability of the guidance system is guar- anteed. It is concluded that the fuzzy variable coefficients strategy is highly effective for head-on intercep- tion as shown in the simulation.