US 5,671,140 A · Fuzzy controller for target intercept guidance

Abstract

A target intercept guidance system for directing a steerable object, such a torpedo. The guidance system senses the bearing and range between a first site and a second site and determines the position of the steerable object as it moves toward the second site. Two error functions are produced. The first error function represents the angle between the bearing from the steerable object to the second site and the course of the steerable object. The second error signal represents the rate of change of that angle. These error signals are classified into first and second sensed linguistic variables based upon membership functions from the first and second sensed variable membership function sets to become fuzzy inputs that produce fuzzy output control output membership functions from a control output membership function set based upon logical manipulation of the fuzzy inputs. These fuzzy control output membership functions are converted into an output having an appropriate form for control.

Claims30

Dependent claims

A system for guiding a steerable object on a minimum time and minimum distance path trajectory launched from a first moving site toward a second site comprising:

sensing means for generating bearing and range signals at said first site representing the bearing and range from said first site to the second site;
steerable object model means for generating signals based upon the signals from said sensing means representing the bearing, course, speed and position of the steerable object;
error signal generating means responsive to the signals from said sensing means and steerable object model means for generating a first sensed variable signal based upon the bearing from said steerable object to said second site and the course of said steerable object and a second sensed variable signal based upon the rate of change of the first sensed variable signal;
fuzzy control means responsive to said first and second sensed variable signals for generating a guidance command at said first site for remotely controlling said steerable object in response to a plurality of fuzzy logic rules;
and
means for transferring the guidance command to said steerable object.

3 more elements

An iterative method using fuzzy controller for guiding a steerable object on a minimum time and minimum distance path trajectory launched from a first moving site to a second site comprising, during each iteration, comprising the steps of:

determining parameters at said first site corresponding to the range and bearing from said first site to the second site, and also corresponding to the bearing, course, speed and position of the steerable object;
generating a first sensed variable signal based upon the bearing from the steerable object to he second site and the course of the steerable object, and generating a second sensed variable signal representing the rate of change of the first sensed variable signal;
generating in said fuzzy controller a guidance command at said first site for remotely controlling the steerable object according to a plurality of fuzzy logic rules in response to the first and second sensed variable signals;
and
transferring the guidance command from the fuzzy controller to the steerable object.

2 more elements

Dependencies are inferred from the claim text.

Fuzzy controller for target intercept guidance

Life of this patent

Fuzzy controller for target intercept guidance

Life of this patent

Abstract

Claims30