Cutoff Insensitive Implicit Guidance via Flight Path Angle Correction

The complexity and cost of solid fuel engines cut-off demands a comprehensive method for guiding these missiles so current required velocity methods can not solve this problem. This paper presents an implicit cut-off insensitive guidance scheme for ballistic missiles. The main idea behind this scheme is to correct the nominal flight path angle, at arbitrary time with respect to value of disturbances and uncertainties such as wind, thrust misalignment, thrust value, aerodynamic coefficients, to satisfy the nominal burnout time conditions. Compared with preset scheme, the proposed scheme is more robust to motor performance uncertainty. The circular error probability of proposed method is calculated about 1.242 km which is 61% less than preset method's circular error probability. It is also simpler and has a lighter calculation load. It is shown that the proposed algorithm has good performance through the computer simulation.The circular error probability of proposed method is calculated about 1.242 km which is 61% less than preset method's circular error probability. It is also simpler and has a lighter calculation load. It is shown that the proposed algorithm has good performance through the computer simulation.