Method and apparatus for detecting guideway breaks and occupation

Abstract

The present invention provides a method and system for detecting guideway anomalies. In particular, the present invention generates and couples a wave pulse into a guideway. The wave pulse travels down the guideway until it reaches an anomaly. The anomaly causes a return wave pulse. The time difference between the generated wave and the return wave allows calculation of the deference to the anomaly.

1 . A method of determining a distance to an anomaly in a guideway, the method preformed on a processor comprising the steps of: 
 generating a wave pulse;    coupling the wave pulse into the guideway;    waiting a predetermined wait time to receive a return pulse from the guideway;    if the return pulse is received within the predetermined wait time, determining whether an anomaly exists on the guideway; and    after the predetermined wait time, repeating the generating, coupling, and waiting step.    
   
   
       2 . The method of  claim 1 , wherein the wave pulse comprises at least one of an electrical wave pulse, an acoustic wave pulse, a magnetic wave pulse, an electromagnetic wave pulse, or a radio frequency wave pulse.  
   
   
       3 . The method of  claim 1 , wherein the guideway comprises at least a pair of conductive members.  
   
   
       4 . The method of  claim 3 , wherein the pair of conductive members are at least partially isolated.  
   
   
       5 . The method of  claim 1 , wherein the determining whether an anomaly exists step comprising detecting impedance variations.  
   
   
       6 . The method of  claim 3 , where the step of detecting impedance variations comprises detecting impedance variations in both conductive members of the pair of conductive members.  
   
   
       7 . The method of  claim 5 , wherein an increase in impedance provides an indication of an anomaly consistent with a break in the guideway and a decrease in impedance provides an indication of an obstruction in the guideway.  
   
   
       8 . The method of  claim 1 , wherein the step of generating a wave pulse generates the pulse over a predetermined pulse timeframe.  
   
   
       9 . The method of  claim 8 , wherein the step of generating a wave pulse generates a plurality of relatively short wave pulses over the predetermined pulse timeframe.  
   
   
       10 . The method of  claim 9 , wherein the plurality of short wave pulses comprise at least a first short wave pulse at a first frequency and a second short wave pulse at a second frequency, different from the first frequency.  
   
   
       11 . The method of  claim 2 , wherein the wave pulse is modulated.  
   
   
       12 . The method of  claim 8 , wherein the predetermined pulse timeframe and the predetermined wait timeframe are based on a minimum distance and maximum distance for which the anomaly is to be detected over the guideway.  
   
   
       13 . The method of  claim 12 , wherein the wave pulse is a short duration high frequency tone burst.  
   
   
       14 . The method of  claim 1 , wherein the predetermined wait time comprises a plurality of predetermined wait timeframes.  
   
   
       15 . The method of  claim 14 , wherein each particular wait timeframe is selected from the plurality of predetermined wait timeframes according to a preselected code basis.  
   
   
       16 . The method of  claim 14 , wherein each particular wait timeframe is selected from the plurality of predetermined wait timeframes on at least one of a random or a pseudo-random basis.  
   
   
       17 . The method of  claim 1 , wherein the step of generating a wave pulse comprises generating a plurality of wave pulses having at least one different characteristic.  
   
   
       18 . The method of  claim 17 , wherein the at least one different characteristic comprises at least one characteristic selected from the group of characteristics consisting of: frequency, modulation code, phase, and amplitude.  
   
   
       19 . A system for detecting anomalies in a guideway, the system comprising: 
 at least one signal generator;    at least one coupler connected to the at least one signal generator, the at least one coupler to transmit the signal generated by the at least one signal generator into the guideway;    at least one signal receiver, the at least one signal receiver connected to the at least one coupler such that a return signal is transmitted from the guideway to the at least one signal receiver; and    a processor, the processor coupled to the signal generator and the at least one signal receiver, such that the processor can determine whether the return signal is indicative of an anomaly based on the signal generated by the at least one signal generator.    
   
   
       20 . The system of  claim 19 , wherein the at least one signal generator and at least one signal receiver form a transceiver.  
   
   
       21 . The system of  claim 19 , wherein the processor causes the at least one signal generator to periodically generate a signal to be transmitted to the guideway.  
   
   
       22 . The system of  claim 19 , wherein the at least one signal processor generates a plurality of signals, at least one of the plurality of signals has at least one different characteristic.  
   
   
       23 . The system of  claim 19 , wherein the at least one signal generator has a uniquely identifiable operating characteristic.  
   
   
       24 . The system of  claim 19  further comprising at least one waveform transformer, the waveform transformer coupled between the at least one signal generator and the at least one coupler to convert the at least one signal generated by the at least one signal generated into a form transmittable to the guideway by the at least one coupler.  
   
   
       25 . The system of  claim 19 , wherein the at least one signal receiver receives a plurality of return signals and the processor correlates the plurality of return signals to compensate for relative movement of the system between transmission and return.  
   
   
       26 . The system of  claim 19  further comprising at least one data link and at least one memory, the at least one data link and the at least one memory coupled to the processor such that the processor can store information regarding detected anomalies.  
   
   
       27 . The system of  claim 26 , wherein the stored information comprises at least one type of information selected from the group of information consisting of: location of the anomaly, impedance variation, rate of movement of anomaly, expected impedance, signal propagation information, guideway imperfections, environmental conditions, or guideway conditions.  
   
   
       28 . The system of  claim 27 , wherein the stored information is provided to the processor to assist in detecting anomalies.  
   
   
       29 . The system of  claim 19 , wherein the at least one signal generator and the at least one signal receiver are located remote from each other such that. anomalies are detected by variations in expected signals received at the at least one signal receiver.  
   
   
       30 . The system of  claim 19  wherein the processor detects anomalies using time domain reflectometry based on the return signal being a reflection of the wave pulse.  
   
   
       31 . The system of  claim 19  wherein the system is mounted on an object traveling along the guideway.  
   
   
       32 . The system of  claim 31 , wherein the object is a rail vehicle.  
   
   
       33 . The system of  claim 32 , wherein the rail vehicle is at least one of a locomotive engine and a railcar.  
   
   
       34 . The system of  claim 31  further comprising: 
 a remote signal generator; and    a remote coupler to transmit the signal from the remote signal generator to the guideway such that the processor can detect anomalies using through-transmission between the remote signal generator and the at least one signal receiver and time domain reflectometry between the at least one signal generator and the at least one signal receiver.    
   
   
       35 . The system of  claim 19  further comprising a data link and a communication link to a broadcast or distributed timing reference such as a global positioning system such that a plurality of systems can be coordinated.  
   
   
       36 . The system of  claim 19 , further comprising at least one indicator, the at least one indicator providing at least one indication selected from a group of indications consisting of: a warning indication, a stop indication, a go indication, distance to anomaly indication, and a rate of approach of anomaly indication.  
   
   
       37 . The system of  claim 36 , wherein the at least one indicator comprises at least one of a light, a display, a whistle, a bell, and a barrier.  
   
   
       38 . A system for detecting breaks, potential breaks, or obstruction in railroad tracks, the system comprising: 
 at least one rail vehicle; and    a pair of conductive rail tracks at least partially isolated from each other;    the at least one rail vehicle comprising: 
 a processor;  
 at least one signal generator, the at least one signal generator coupled to the processor such that the processor causes the at least one signal generator to generate electrical waveform information at a selected time;  
 at least one waveform generator connected to the at least one signal generator to covert the waveform information into a transmittable waveform capable of traveling along at least one track of the pair of conductive rail tracks;  
 at least one track coupler to transfer the transmittable waveform from the at least one waveform generator to the at least one track and to transfer a return waveform from the at least one track;  
 at least one signal receiver coupled to the at least one track coupler to receiver the return waveform from the at least on track and convert the return waveform into a return signal useable by the processor; the at least one signal receiver coupled to the processor to transfer the return signal to the processor, wherein the processor can detect anomalies.