過去在面對終端攔截的導引問題時，許多導引律採用的設計法則是根據視界線的改變率為基礎的PNG導引律或其衍生設計，目標物的資訊經由外部的導引迴圈計算出飛彈所需的轉彎命令後，再交由內部的自動駕駛迴圈來改變飛彈控制面角度的訊號。這種架構往往由於外部迴圈不考慮真正的飛彈數學模型，而無法完全達到其理想的效能；更甚者亦有可能在飛彈與目標物極為接近之時，轉彎命令會由於視界線的急遽改變而有發散之虞。本文以整合飛彈數學模型所得的ZEM為基礎，配合積分型順滑模態控制的概念，設計出具有平滑控制訊號及低誤失距離的整合型導引律，相較於傳統順滑模態控制，不具切跳現象為其優點。

In the previous time, most guidance law designs were chosen to be according to the line of sight rate, which is known as PNG law. The required missile maneuver command is calculated by means of the outer guidance loop alongside with the target information, which is transferred to the inner autopilot loop to change the control surface signal. The ideal performance may not be achieved since the real missile mathematical model is not anticipated in the outer loop in this framework, and the maneuver command may diverge as the line of sight rate changes suddenly when the target is very close. Based on ZEM obtained by means of integrated with missile mathematical model and integral-type sliding mode control, an integrated guidance law with smooth control signal and relatively low miss distance is proposed; the proposed guidance law neither has the chattering phenomena comparing with the conventional sliding mode design.

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