ADVANCED GUIDANCE LAWS FOR ACCELERATION-CONSTRAINED MISSILE, RANDOMLYMANEUVERING TARGET AND NOISY MEASUREMENTS

An explicit, closed-form formulae of advanced guidance laws for a line ar, time-invariant, acceleration-constrained arbitrary-order missile, and a linear, time-invariant, arbitrary-order, randomly maneuvering ta rget with noisy position measurements are derived, Two approaches are presented. The first approach derives the optimal guidance law for a q uadratic objective. The solution is the guidance law for deterministic system with limiting on the commanded acceleration applied on the est imated state, The limiting function in this case is the saturation fun ction. The second approach derives a control law called the average in put guidance law. This approach is based on the idea of applying the a verage of the input that would have been applied to the plant if the n oises were known. The solution has similar structure, It is the guidan ce law for deterministic system with limiting on the commanded acceler ation applied on the estimated state. The limiting function in this ca se is from the family of describing functions of the saturation functi on. The formulas of the different guidance laws are given in terns of the transfer function of the missile and acceleration constraint, the shaping filter of the maneuver of the target, responses to initial con ditions, error variance matrix of the estimated state and weights in t he criterion It is demonstrated by simulations that although the optim al guidance law has improved performance in terms of the miss distance , the suboptimal average input guidance law consumes less energy.