Impact Angle Constrained Suboptimal Terminal Guidance of Interceptors for Air Defence

A computationally efficient suboptimal Model Predictive Spread Acceleration Guidance (MPSAG) law is proposed for terminal phase of air defense missiles with impact angle constraint. This nonlinear guidance law provides closed form solution of lateral acceleration (latax) update. The latax demand is purposefully spread over the available time-to go (tgo), which is done by parameterizing it with respect to tgo as a straight line and parabola. It enables guidance law to avoid the latax saturation limits. A tgo adjustment mechanism is also proposed in this paper for enhancing the effectiveness of the proposed guidance law. Simulation studies have also been carried out incorporating autopilot lags in the loop to have a realistic evaluation of the proposed guidance design. Algorithm is tried to make online using iteration unfolding.