QUALITY CONTROL ENGINE FOR COMPLEX PHYSICAL SYSTEMS

• US 20160154802A1
• Filed: 12/01/2015
• Published: 06/02/2016
• Est. Priority Date: 12/02/2014
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Laboratories America Inc (NEC Corporation)
• Inventors: Yan, Tan, Jiang, Guofei, Chen, Haifeng, Takehiko, Mizoguchi
• Application Number:
  US14/956,352
• Publication Number:
  US 20160154802A1
• Time in Patent Office: Days
• CPC Class Codes: G05B 19/4184 characterised by fault tolerance, reliability of production system
• CPC Class Codes: G05B 2219/32179 Quality control, monitor production tool with multiple sensors
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Systems and methods for quality control for physical systems, including a quality control engine for transforming raw time series data collected from each of a plurality of sensors in the physical system into one or more sets of feature series by extracting features from the raw time series. Feature ranking scores are generated for each of the sensors by ranking each of the features using an ensemble of feature rankers, and fused importance scores are generated by aggregating the feature ranking scores for each of the sensors and combining ranking scores from each ranker in the ensemble. System quality is controlled by identifying sensors responsible for quality degradation based on the fused importance scores.

Claims

1. A method for quality control for a physical system, comprising:

transforming raw time series data collected from each of a plurality of sensors in the physical system into one or more sets of feature series by extracting features from the raw time series;

generating feature ranking scores for each of the sensors by ranking each of the features using an ensemble of feature rankers;

generating fused importance scores by aggregating the feature ranking scores for each of the sensors and combining ranking scores from each ranker in the ensemble; and

controlling system quality by identifying sensors responsible for quality degradation based on the fused importance scores.

2. The method as recited in claim 1, wherein the ensemble of feature rankers considers a plurality of aspects of feature interactions and their dependencies to generate the feature ranking scores for each of the sensors.

3. The method as recited in claim 1, wherein the ensemble of feature rankers includes at least one of a regularization-based ranker, a tree-based ranker, or a nonlinear ranker.

4. The method as recited in claim 1, wherein the physical system is a physical manufacturing system.

5. The method as recited in claim 1, wherein a sliding window technique is employed during the transforming to extract the features while preserving continuity along a time axis.

6. The method as recited in claim 1, wherein the features are stored in a pre-defined library, the library including a plurality of feature definitions describing different aspects of signal dynamics.

7. The method as recited in claim 6, wherein the different aspects include at least one of characteristics of time series in a temporal domain, characteristics of time series in a frequency domain, temporal dependencies of individual time series, or temporal dependencies across different time series.

8. The method as recited in claim 1, wherein the feature ranking scores are normalized using a sigmoid function before generating the fused importance scores.

9. A quality control engine for a physical system, comprising:

a time series transformer for transforming raw time series data collected from each of a plurality of sensors in the physical system into one or more sets of feature series by extracting features from the raw time series;

an ensemble of feature rankers configured to rank each of the features to generate feature ranking scores for each of the sensors;

a combiner for generating fused importance scores by aggregating the feature ranking scores for each of the sensors and fusing ranking scores from each ranker in the ensemble; and

a controller for managing system quality by identifying sensors responsible for quality degradation based on the fused importance scores.

10. The system as recited in claim 9, wherein the ensemble of feature rankers considers a plurality of aspects of feature interactions and their dependencies to generate the feature ranking scores for each of the sensors.

11. The system as recited in claim 9, wherein the ensemble of feature rankers includes at least one of a regularization-based ranker, a tree-based ranker, or a nonlinear ranker.

12. The system as recited in claim 9, wherein the physical system is a physical manufacturing system.

13. The system as recited in claim 9, wherein a sliding window technique is employed during the transforming to extract the features while preserving continuity along a time axis.

14. The system as recited in claim 9, wherein the features are stored in a pre-defined library, the library including a plurality of feature definitions describing different aspects of signal dynamics.

15. The system as recited in claim 14, wherein the different aspects include at least one of characteristics of time series in a temporal domain, characteristics of time series in a frequency domain, temporal dependencies of individual time series, or temporal dependencies across different time series.

16. The system as recited in claim 9, wherein the feature ranking scores are normalized using a sigmoid function before generating the fused importance scores.

17. A computer-readable storage medium including a computer-readable program, wherein the computer-readable program when executed on a computer causes the computer to perform the steps of:

transforming raw time series data collected from each of a plurality of sensors in the physical system into one or more sets of feature series by extracting features from the raw time series;

generating feature ranking scores for each of the sensors by ranking each of the features using an ensemble of feature rankers;

generating fused importance scores by aggregating the feature ranking scores for each of the sensors and combining ranking scores from each ranker in the ensemble; and

controlling system quality by identifying sensors responsible for quality degradation based on the fused importance scores.

18. The computer-readable storage medium as recited in claim 17, wherein the ensemble of feature rankers considers a plurality of aspects of feature interactions and their dependencies to generate the feature ranking scores for each of the sensors

19. The computer-readable storage medium as recited in claim 17, wherein the ensemble of feature rankers includes at least one of a regularization-based ranker, a tree-based ranker, or a nonlinear ranker.

20. The computer-readable storage medium as recited in claim 17, wherein a sliding window technique is employed during the transforming to extract the features while preserving continuity along a time axis.