Patent ID: 9031791
Filing Date: 2015-05-12
Classification: B61K,B61L,G01N,G01V

Abstract:
1. A system for detection of rock fall in a vicinity of a section of railway track, the system comprising: a plurality of ballast sensors spaced apart along the track section, each ballast sensor located in a ballast proximate to the track section but spaced apart from rails and ties associated with the track section and each ballast sensor sensitive to acoustic energy and configured to generate a corresponding ballast sensor signal in response to detecting acoustic energy; a signal processing unit operatively connected to receive the ballast sensor signals from the plurality of ballast sensors, the signal processing unit configured to detect rock fall events in a vicinity of the track section based, at least in part, on the ballast sensor signals; wherein the signal processing unit is configured to detect a plurality of different types of events comprising rock fall events, train events wherein a train travels over the track section and highrail vehicle events wherein a highrail vehicle travels over the track section and wherein the signal processing unit is configured to discriminate rock fall events from train events or highrail vehicle events; wherein the signal processing unit is configured to detect an event for a particular one of the ballast sensors based, at least in part, on its corresponding ballast sensor signal; wherein the signal processing unit is configured to detect a start of the event and an associated time t wherein the signal processing unit is configured to determine the STA/LTA parameter for the corresponding ballast sensor signal according to one of: where: x i represents a value of an i th sample of the corresponding ballast sensor signal, n is an index of a current sample x n , a is an STA duration constant, b is an LTA duration constant and is the STA/LTA parameter; and where: x i represents a value of an i th sample of the corresponding ballast sensor signal, n is an index of a current sample x n , a is an STA duration constant, c is an experimentally determined constant that is representative of an LTA during event free times and is the STA/LTA parameter.