US 5,671,139 A · 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.

Claims32

Dependent claims

A hierarchical control system for guiding a steerable object from a launching vehicle toward a target in response to any of competing sets of multiple goal control rules based upon signals from sensing means corresponding to bearings from the launching vehicle to the steerable object and to the target, said hierarchical control system comprising:

first error means for generating first goal sensed variable signals in response to the signals from said sensing means;
second error means for generating second goal sensed variable signals in response to the signals from said sensing means;
sensed variable membership means including a plurality of sensed variable membership functions for converting the first and second sensed variable signals based on the corresponding first and second sensed variable membership functions into at least first and second sensed linguistic variables;
control output membership means for producing a plurality of control output membership functions;
multi-goal rule based means including competing multiple output control rules interposed between said sensed variable membership means and said control output membership means for selecting at least one of said control output membership functions in accordance with one of the competing multiple output control rules selected by said multi-goal rule based means in response to the first goal sensed variable signals;
guidance command generating means for generating a guidance command in response to the selection by said multigoal based means;
and
a guidance command transfer means for transferring the guidance command to the steerable object, thereby guiding the steerable object from the launching vehicle toward the target.

5 more elements

An iterative method for guiding a steerable object from a launching vehicle to a target in response to a plurality of competing goals for determining guidance wherein each iteration comprises the steps of:

generating first sensed bearings from the launching vehicle to the steerable object and to the target and second sensed bearings that indicate the position of the steerable object with respect to a predetermined zone of positions;
selecting at least one of a first set of sensed variable membership functions in response to the first sensed bearings;
determining which of the multiple competing goals is to control guidance in response to the second sensed bearings;
selecting at least one of the first and second sets of predetermined sensed linguistic variables in response to the second sensed bearings based upon predetermined goal selection rules;
selecting at least one control output linguistic variable from a predetermined set of control output linguistic variables according to predetermined rules and in response to the selected sensed linguistic variables from the first set when the second sensed bearings indicate that the steerable object is proximate or inside the predetermined zone and in response to the second set when the second sensed bearings indicate that the steerable object is outside the predetermined zone;
generating a guidance command for controlling the steerable object in response to the control output linguistic variables selection;
and
transferring the guidance command to the steerable object.

5 more elements

Dependencies are inferred from the claim text.

Hierarchical fuzzy controller for beam rider guidance

Life of this patent

Hierarchical fuzzy controller for beam rider guidance

Life of this patent

Abstract

Claims32