Design of optimal central guidance of an underwater vehicle in the modeled ship wake

The purpose of this paper is to provide a new algorithm for guidance of an underwater vehicle to reach its target, and demonstrate its effectiveness by simulation with a computer code. The meant of target in here is to chase a ship on the surface of the water. In order to do this, one of the most effective methods is to follow the ship wake which produced behind it. Disadvantages of wake guidance can be mentioned as zigzag motion for rediscovering the wake in its path which according to the decreasing linear speed of approaching the target, sometime it doesn't reach the target and collision fails. Therefore various ideas, with both positive and negative aspects, have been introduced to improve movement in the wake path. In this paper, a new guidance algorithm for running an underwater vehicle at the center of wake, which is named central guidance, is introduced that results an optimal path that by using geometric bases, determining the center of the wake in guidance phase like a central line. Then, using the optimal least effort method, the path to central line is presented.  Also, to test this method, the wake of a ship is modelled and programed and its code is used in the guidance program to simulate the performance of this method.