Singularity control strategy in bank-to-turn guidance for penetration guidance weapon

To solve the roll command singularity in end-game of bank-to-turn(BTT) for penetration guidance weapon, the formation principle of singularity and main influence factors of BTT-90 logic were analyzed based on the method of insensitivity analysis with partial derivative. The non-dimensional overload equation of guidance law was derived, and the simulation of actual trajectory was carried out. The regularity of the command varying with time was given, and it was proved that the singularity exists only in the stage of overload command exceeding zero. A singularity control strategy was designed, and the BTT control was divided into the normal zone and singularity zone, and the roll command smoothing method was used in singularity zone. The switch scheme was introduced. The simulation result shows that the strategy can eliminate the singularity existing in the BTT guidance and has few influence on the accuracy of guidance.