Incremental learning of nonlinear regression networks for machine condition monitoring

1. A method for identifying a potential fault in a system, comprising:

obtaining a set of training data;

selecting a first kernel from a library of two or more kernels and adding the first kernel to a regression network;

selecting a next kernel from the library of two or more kernels and adding the next kernel to the regression network;

refining the regression network using a leave-one-out method in which the regression network is iteratively improved by removing a single kernel from the regression network and replacing the removed kernel with a replacement kernel from the library of kernels and then repeating the removing and replacing steps for the kernels of the regression network until a desired level of convergence between the training data and the regression network is achieved; and

identifying a potential fault in the system using the refined regression network.

2. The method of claim 1 , wherein the step of selecting a next kernel from the library of kernels and adding the next kernel to the regression network is repeated until a regression error has been reduced to a predetermined level.

3. The method of claim 1 , wherein the step of selecting a next kernel from the library of kernels and adding the next kernel to the regression network is repeated until a regression error has been minimized.

4. The method of claim 1 , wherein the first kernel is selected from among the library of kernels by calculating a cost function for each of the kernels of the library and selecting the kernel that results in a lowest cost function.

5. The method of claim 1 , wherein the next kernel is selected from among the library of kernels by calculating a cost function for each of the kernels of the library and selecting the kernel that results in a lowest cost function.

6. The method of claim 1 , wherein refining the regression network additionally comprising repeating the steps of removing and replacing a kernel from the regression network until a cost function is minimized.

7. The method of claim 1 , wherein the library of kernels includes a linear kernel, a Gaussian kernel, a polynomial kernel, quadratic kernel, or a sigmoid kernel.

8. The method of claim 1 , wherein the step of identifying a potential fault in the system using the refined regression network comprises:

obtaining operational sensor data;

estimating an expected monitored sensor value based on the operational sensor data and the refined regression network;

obtaining an actual value from the monitored sensor; and

identifying a potential fault when the actual value of the monitored sensor deviates from the expected monitored sensor value by more than a predetermined tolerance level.

9. A system for identifying potential faults in a machine, comprising:

a training data database including set of training data;

a kernel database including two or more kernels;

a selection unit for selecting a kernel from a library of two or more kernels and adding the kernel to a regression network;

a refining unit for refining the regression network using a leave-one-out method in which the regression network is iteratively improved by removing a single kernel from the regression network and replacing the removed kernel with a replacement kernel from the library of kernels and then repeating the removing and replacing steps for the kernels of the regression network until a desired level of convergence between the training data and the regression network is achieved;

a set of sensors for monitoring attributes of the machine; and

an identification unit for identifying a potential fault in the machine using the refined regression network and data obtained from the set of sensors.

10. The system of claim 9 , wherein the selection unit repeats the selecting of a kernel and adding the selected kernel to the regression network until a regression error has been minimized or reduced to a predetermined level.

11. The system of claim 9 , wherein the selection unit selects a kernel from among the library of kernels by calculating a cost function for each of the kernels of the library and selecting the kernel that results in a lowest cost function.

12. The system of claim 9 , wherein the refining unit repeats the refining process until a regression error has been reduced to a predetermined level or a cost function is minimized.

13. A computer system comprising:

a processor; and

a program storage device readable by the computer system, embodying a program of instructions executable by the processor to perform method steps for identifying a potential fault in a system, the method comprising:

obtaining a set of training data;

selecting a first kernel from a library of two or more kernels and adding the first kernel to a regression network;

selecting a next kernel from the library of two or more kernels and adding the next kernel to the regression network;

refining the regression network using a leave-one-out method in which the regression network is iteratively improved by removing a single kernel from the regression network and replacing the removed kernel with a replacement kernel from the library of kernels and then repeating the removing and replacing steps for the kernels of the regression network until a desired level of convergence between the training data and the regression network is achieved; and

identifying a potential fault in the system using the refined regression network.

14. The computer system of claim 13 , wherein the step of selecting a next kernel from the library of kernels and adding the next kernel to the regression network is repeated until a regression error has been minimized or reduced to a predetermined level.

15. The computer system of claim 13 , wherein the first kernel and the next kernel are each selected from among the library of kernels by calculating a cost function for each of the kernels of the library and selecting the kernel that results in a lowest cost function.