Hierarchical fuzzy controller for beam rider guidance

Abstract

A beam rider guidance system for directing a steerable object, such as a torpedo. The guidance system is located at a launching vehicle and senses the bearings from the launching vehicle to a target and to the steerable object as it moves toward the target. Various error signals are then generated and classified into membership functions of different sensed variable membership function sets based upon primary and secondary goals to become fuzzy inputs to a controller that produces fuzzy output control output membership functions from a control output membership function set based upon logical manipulation of the fuzzy inputs. The control system performs this classification and selection according to sometimes competing goals of excluding the torpedo from a particular operating zone while guiding the torpedo in response to a bearing through that operating zone. The selected fuzzy control output membership functions are converted into an output having an appropriate form for control, subject to optional conditioning to prevent unwanted effects and assure good behavior for different tactical parameters.