Fuzzy logic based system and method for information processing with uncertain input data

• US 6,282,526 B1
• Filed: 01/20/1999
• Issued: 08/28/2001
• Est. Priority Date: 01/20/1999
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Ganesh, Chidambar
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): STARKS, WILBERT L
• Application Number:
  US09/246,208
• Time in Patent Office: 951 Days
• Field of Search: 706/10, 706/8, 382/156, 342/13
• US Class Current: 706/8
• CPC Class Codes: G05B 13/0275 using fuzzy logic only
• CPC Class Codes: G06N 7/02 using fuzzy logic computing arrangements based on biological models G06N3/00; computing arrangements using knowledge-based models G06N5/00

Abstract

A fuzzy logic information processing system and method are disclosed that may be used not only with known or definite data input but also with uncertain data input. The uncertain data input may be represented by a set of values wherein the possibility of any particular or specific value within the set being the true or accurate value is uncertain. The preferred embodiment of the system provides for an extensor to extend or map a representation of the uncertain data into at least one additional dimension related to dimensions of a set of rules used for making fuzzy logic inferences. The set of rules may be provided effectively in a mapped or graphed form. The set of rules and uncertain data are combined, for instance by locating intersection regions, to produce an output set that may be also be described as a map or plot. In a presently preferred embodiment the uncertain inputs and rules are represented mathematically or symbolically and then operated on to produce an output set. A projector then projects the output set to the desired output dimension as an output for the system. The system output may then be used for control purposes such as, for example only, a combat control system to provide a tactical picture, decision aid, presets for a guidance system, or the like.

Claims

1. A fuzzy logic system for processing information from at least one input that is associated with one or more physical phenomena, said at least one input being described as an input set including a plurality of possible values with uncertainty as to which of said plurality of possible values is the actual value of said at least one input, said fuzzy logic system comprising:

an extensor for operating on said input set to produce an operated set of values;

an inference engine that includes a plurality of rules related to said one or more physical phenomena, said inference engine being operable for comparing said operated set of values with said plurality of rules for producing a conditioned set of values; and

a projector for producing an output signal from said conditioned set of values.

2. The system of claim 1 wherein said output signal is used for producing a display.

3. The system of claim 1 wherein said output signal is used as a control signal.

4. The system of claim 1 wherein said operated set operated set of values may be represented by a first map and said rules may be represented by a second map.

5. The system of claim 4 wherein said conditioned set may be represented as a third map that is an intersection of said first map and said second map.

6. The system of claim 5 wherein said projector produces a signal that may be represented as a conditioning of said third map with respect to desired output units.

7. A method for a control system for utilizing uncertain input data that has an uncertain value contained within an input set of possible values, said uncertain input data being associated with one or more physical phenomena, said method comprising the steps of:

representing said uncertain input data for use in a fuzzy logic system, said representation describing said input set of possible values without designating a specific of said possible values for said uncertain input data;

providing a plurality of rules fi r said fuzzy logic system in terms related to said uncertain input data; and

inferring an output from said fuzzy logic system based on said plurality of rules and said set of possible values for said input data.

8. The method of claim 7 further comprising operating on said input set of possible values to produce a first set of possible values.

9. The method of claim 8 further comprising representing said rules for said fuzzy logic system in terms that may be described by a second set of values.

10. The method of claim 9 further comprising producing a third set of values from said first set of values and said second set of values.

11. The method of claim 10 wherein said third set comprises an intersection of said first set and said second set.

12. The method of claim 7 further comprising:

producing a tactical picture that incorporates said output from said fuzzy logic system.

13. The method of claim 7, further comprising:

providing a system control signal from said output of said fuzzy logic system.

14. A control system, comprising:

at least one sensor for producing a sensor signal, said sensor signal being used to produce input information for said control system; and

a fuzzy logic inference system for said control system, said fuzzy logic inference system being operable for receiving said input information when said input information is definite and also when said input information is uncertain such that a representation of said information is produced when said input information is definite and also when said information is uncertain, when said input information is uncertain said representation provides for a set of possible values for said input information, said fuzzy logic inference system being operable for comparing said representation to a set of rules to produce an output control signal.

15. The control system of claim 14 wherein said output control signal is used to create a tactical picture display.

16. The control system of claim 14 wherein said fuzzy logic inference system further comprises:

an extensor for operating on said input information to produce a first map by introducing at least one additional dimension to said input information, said at least one additional dimension being related to said set of rules.

17. The control system of claim 16 wherein said rules are represented by a second map that includes said at least one additional dimension.

18. The control system of claim 17 wherein said fuzzy logic inference system is operable for comparing said first map to said second map to produce a third map.

19. The control system of claim 18 wherein said fuzzy logic inference system further comprises:

a projector for operating on said third map to form a projection onto a dimension for said output control signal.

20. The control system of claim 14 further comprising:

a decision support system wherein said output control signal is used to provide a display depicting range of possibilities.