On closed-loop controls in pursuit-evasion (Q580206)

The problem of generating optimal closed loop controls in pursuit evasion differential games is addressed. A hybrid technique composed of a differential dynamic programming method and a singular perturbation method is introduced. The first method is used in those parts where the latter is weak. The method so created has an open loop character. By having the open loop solution updated as often as possible when new measures of the state have been estimated, the method will be near optimal closed loop. The game problem is discussed in terms of optimistic or pessimistic strategies, based on assumptions on the evader's strategy. In practice the evader may not do his best. The demonstrative example is in the horizontal plane, formulated as a game of degree. The pursuer uses a variable speed model with throttle and turn controls. The algorithm can be used on a small computer and can thus be implemented on an airborne computer.