Abstract: A velocity-to-begained guidance law for exoatmospheric targets is proposed for an interceptor with a fuelexhaustionshutoff solid rocket motor. First, the assumption is made that the interceptor has attained the inertial velocity-to-begained, and the predicted miss distance is obtained by using the parameter of remaining velocity increment. Then the correction of the velocity-to-begained is attained by using the perturbation matrix of the Kepler orbit, and the predicted miss distance could be eliminated by it. Finally, the command thrust orientation is determined by the sum of the inertial velocity-to-begained and its correction. The initial command thrust orientation is determined by Lambert guidance. A semi-analytical trajectorypredicting method which takes into consideration the impact of J2 item perturbation is presented to decrease the amount of calculation and reduce errors. A measurement method for the remaining velocity increment is proposed to improve the robustness of guidance against motor parameter uncertainties. Simulation results demonstrate that when using the proposed guidance law, the command thrust orientation varies more evenly in a narrower range, and the miss distance is about two orders of magnitude lower as compared with conventional general energy management (GEM) guidance.

Key words: predicted miss distance, Lambert intercept, velocity-to-be-gained guidance, remaining velocity increment, inertial velocity-to-be-gained, J2 item perturbation