A New United Proportional Navigation Guidance for Impact Angle Constraint without Measurement Distance between Vehicle and Target

This paper proposed a united proportional navigation guidance (UPNG) method to alleviate the command saltation with an impact angle constraint under condition of no real-time distance between vehicle and target (line-of-sight (LOS) distance). Firstly, based on biased (BPNG), smooth-biased (SBPNG) was proposed, whose bias term designed as trigonometric function. In SBPNG method, due continuous smooth change term, would not saltus anymore, controlled by integral component. Secondly, combining variable coefficient (VCPNG) established. UPNG because there LOS distance, function difference expected estimated angle, so closed-loop control realized. Finally, lot simulation experiments different laws were carried out without distance. The results verify that in this solves problem effectively has better robustness control.