在空地导弹的导引律中，比例导引法与直接导引法各有优缺点。

Among the guidance principles of the air-to-ground missile, the proportional guidance method and the direct guidance method have their respective advantages and disadvantages.

本文就此类问题展开深入研究，提出几种能克服不光滑非线性影响的控制系统设计方法，并将所提出的控制方法应用到空地导弹控制系统中。

This paper deeply studies these problems. Several methods of the control of systems with nonsmooth nonlinearities are presented and applied to air-ground missile system.