Hot rail wheel bearing detection system and method
A system for detecting a hot surface is provided. The system includes a sensor for sensing an infrared radiation radiating from the hot surface and a high pass filter to eliminate low frequency components from the sensor signal. The system also includes an absolute value module to compute absolute values of a filtered signal, a first comparator to compare output of the absolute value module to a first threshold and a peak detector to report a peak value of the sensor signal's output. The system further includes a second comparator to compare output of peak detector to a second threshold.
1. A system for detecting a moving hot bearing or wheel of a rail car comprising:
a sensor for sensing radiation from the hot bearing or wheel;
a high pass filter configured to generate filtered sensor signals by eliminating low frequency components from signals from the sensor;
a first comparator configured to compare the filtered sensor signals to a first threshold;
a peak detector configured to report a peak value of the sensor signals; and
a second comparator configured to compare output of the peak detector to a second threshold.
2. The system of claim 1 , comprising an absolute value module configured to compute absolute values of the filtered signals for application to the first comparator, and wherein the first comparator compares the absolute values of the filtered signals to the first threshold.
3. The system of claim 1 , wherein the peak detector is enabled and disabled from outputting signals based upon the comparison by the first comparator.
4. The system of claim 1 , wherein at least one of the filter, the first comparator, the peak detector and the second detector is implemented in programmed digital processor.
5. The system of claim 1 , wherein at least one of the filter, the first comparator, the peak detector and the second detector is implemented in an analog domain.
6. The system of claim 1 , wherein the second threshold is adjusted during operation of the system.
7. The system of claim 6 , wherein the second threshold is adjusted based upon a FIFO analysis of decisions.
8. The system of claim 1 , wherein the first comparator is further configured to disable the peak detector when there is a noise in an output signal of the sensor.
9. A method for detecting a moving hot bearing or wheel of a rail car comprising:
detecting signals from the hot bearing or wheel;
high pass filtering the signals;
comparing the filtered detected signals to a first threshold;
detecting peaks in the detected signals; and
comparing the peaks to a second threshold to determine whether the hot bearing or wheel is likely hotter than desired.
10. The method of claim 9 , comprising enabling and disabling the peak detector from outputting signals for comparison based upon the comparison of the filtered signals to the first threshold.
11. The method of claim 9 , comprising determining absolute values of the filtered signals, and wherein the filtered signals compared to the first threshold are absolute values of the filtered signals.
12. The method of claim 9 , wherein the second threshold is adjusted during operation processing of the signals.
13. The method of claim 12 , wherein the second threshold is adjusted based upon a FIFO analysis of decisions.
14. The method of claim 9 , comprising outputting a notification indicating that a bearing or wheel is hotter than desired.
15. The method of claim 14 , comprising transmitting the notification to a location remote from a train in which the rail car is part.
16. The method of claim 9 , wherein at least one of the high pass filtering, the comparison of the filtered detected signals, and the peak detection is implemented in an analog domain.
17. The method of claim 9 , wherein detecting peaks further comprises detecting peaks in the detected signals when the detected signals are noise free.