Method and apparatus for detecting railway activity

A method for reporting suspicious conditions on a railway, comprising the steps of:

• a. monitoring the railway to detect sound waves resulting from physical vibrations thereon occurring on the railway due to a disturbance located away from a sensor of the sound waves;
• b. analyzing said detected sound waves to identify a detected condition on the railway;
• c. generating an alarm if said detected condition indicates a predetermined suspicious condition on the railway;
• and
• d. processing said detected sound waves having a said detected condition indicating a predetermined suspicious condition to store said detected sound waves in a sound file.

A method for reporting suspicious conditions on a railway, comprising the steps of:

• a. monitoring the railway to detect sound waves resulting from physical vibrations thereon the monitoring being performed through an acoustic sensor circuit having at least one acoustic sensor coupled to each rail of said railway, wherein one said acoustic sensor being coupled to one rail of said railway outputs a first analog signal V1 indicating sound waves detected thereon, and wherein another said acoustic sensor coupled to another rail of said railway outputs a second analog signal V2 indicating the sound waves detected therein;
• b. analyzing said detected sound waves to identify a detected condition on the railway, said analyzing being performed through an acoustic analyzer unit having at least one filter for filtering said first analog signal V1 and said second analog signal V2, and a logic circuit for detecting whether said filtered signals V1 and V2 indicate a suspicious condition on said railway;
• determining whether filtered signals V1 and V2 indicate a given suspicious condition on the railway, including steps of;
• taking the absolute value of the difference between V1 and V2 to determine a differential X;
• comparing differential X to some minimum differential threshold X.sub.o to determine if a given suspicious condition exists on said railway;
• comparing signal V1 to a minimum threshold V.sub.o to determine whether said rail from which V1 is derived has a suspicious condition thereon;
• and
• comparing signal V2 to a minimum threshold V.sub.o to determine whether said rail from which V2 is derived has a suspicious condition thereon;
• and
• c. generating an alarm if said detected condition indicates a predetermined suspicious condition on the railway;
• and
• d. processing said detected sound waves having a said detected condition indicating a predetermined suspicious condition to store said detected sound waves in a sound file.

A warning system for reporting activities on conditions of a railway, comprising:

• an acoustic sensor circuit coupled to the railway for detecting sound waves resulting from physical vibrations thereon;
• the acoustic sensor circuit comprising at least one acoustic sensor coupled to each rail of the railway;
• an acoustic signal processing unit coupled to said acoustic sensor circuit for storing said detected sound waves in a sound file;
• an acoustic analyzer unit coupled to said acoustic sensor circuit for analyzing said detected sound waves to identify the activities on and conditions of the railway, and for generating an alarm indicating a hazardous condition on the railway;
• said acoustic analyzer unit comprising at least one acoustic filter for filtering said detected sound waves, and a logic circuit for analyzing said filtered detected sound waves and for generating said alarm if said sound waves meet a predetermined suspicious condition;
• means for communicating said alarm to said acoustic processing unit;
• an alarm communications system for reporting said alarm generated by said acoustic analyzer to a central monitoring station;
• said alarm communications system being a wireless communication system;
• comprising in turn a packet data wireless system, wherein said packet data is communicated over a plurality of trackside communications devices;
• with the wireless communication system reporting said alarm to a locomotive traveling on the railway;
• said acoustic signal processing unit comprising an analog-to-digital converter for converting said detected sound waves from analog to digital, a digital signal processor for formatting said digital sound waves in a sound file format, and a processor having a storage medium for storing said sound file formatted digital detected sound waves;
• a cellular communications system for communicating signals representing said detected sound waves to said central monitoring station and a local retrieval device for retrieving said detected sound waves stored in said sound file format.