MXPA99005339A - Method and apparatus to determine the presence and orientation of an intermediate via placed between the roads on which a t - Google Patents

Abstract

An apparatus is described for determining the presence of a third rail placed between parallel railway tracks, when a train progresses along parallel railway tracks and, further, to determine the relative direction of movement of the third rail, with respect to two first lanes and, in addition, to determine the speed at which the third lane moves with respect to the first lanes, which is a low power radar sensor placed under the railway vehicle and directed towards the lane on the opposite side vehicle. In a preferred embodiment, two rail detectors are shown, which are placed on opposite sides of the rail vehicle. The radar detectors are coupled with an on-board computing device and with other components of an advanced train control system, which can be used to accurately locate the train on separate parallel tracks and, in addition, to update and increase the position information used by the train control system, advanced. The system includes GPS receivers and wheel tachometers to provide alternative sources of information for position determination.

Description

METHOD AND APPARATUS TO DETERMINE THE PRESENCE AND ORIENTATION OF A VA INTERMEDIA PLACED BETWEEN THE ROADS ON THE WHAT A TRAIN IS DISPLACED.

BACKGROUND OF THE INVENTION The present invention relates in a general way to railroads, and more specifically relates to train control systems and, even more particularly, relates to the automatic and remote detection of track changes. In the past, train control systems had been used to facilitate the operation of trains. These train control systems have endeavored to increase the density of trains in a track system while maintaining, simultaneously, the positive separation of trains. The problem of maintaining positive separation of trains becomes more difficult when parallel tracks are present. Often, there are parallel tracks with numerous cross-track changes to change from one track to another. Frequently, it is very difficult for electronic and automatic systems such as train control systems to positively determine which of the different parallel train tracks a train can be located at any particular time. For example, when the tracks are parallel, they are typically placed very close to each other, with a center-to-center distance of approximately 4.27 m (fourteen (14) feet). In the past, several different methods have been tried to resolve the potential ambiguity of which way, from a group of parallel paths, may be using a train. These methods have included using receivers of global positioning systems, track circuits and inertial navigation sensors. Those methods of the prior art to determine which way is being used, each have their own significant disadvantages. First, standard GPS receivers are usually unable to positively resolve the position of the train with the required degree of accuracy. The separation of approximately 4.27 m (fourteen (14) feet) between the tracks is often too short for normal GPS receivers to provide a positive determination of the use of the track. The use of differential GPS increases the accuracy; that is, it reduces the uncertainty in the determined position. However, differential GPSs would require the placement of numerous differential GPS transmitting "stations", remotely located throughout the country. The United States is currently not equipped with a sufficient number of differential GPS transmitting stations, to provide the necessary accuracy at all points along the rail systems of the United States. Track circuits that have been used in the past to detect the presence of a train on a particular track also require significant infrastructure investment to provide broad coverage. Currently, there are vast areas of "dark territory", in which track circuits are not available. Additionally, those track circuits are subject to damage in remote locations and are susceptible to intentional sabotage. Inertial navigation sensors proposed in the past have included gyroscopes and acceleration sensors. Gyroscopes are capable of detecting a very gradual return; however, turns with sufficient accuracy to detect such turns are very expensive. Acceleration sensors, although less expensive than sensitive turns, typically lack the ability to detect the necessary movement of a train, especially when a track change designed for high speed from one track to another is being made at speeds Very low. Consequently, there is a need for an improvement in advanced train control systems that overcomes the problems previously established.

BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to provide a train control system having positive train separation capabilities., improved. A feature of the present invention includes a train control system having capabilities to detect the direction a train takes through the track changes. An advantage of the present invention is that it reduces the ambiguity of track occupancy, which is often present when trains operate within a group of parallel tracks. Another object of the present invention is to improve the accuracy of the determination of the position of the trains. Another feature of the present invention includes a sensor on the dashboard of the train, to detect intermediate tracks that exist between the wheels of a locomotive when it passes between a point of change of track and a "heart of the junction way" or other crossing roads. An advantage of the present invention is that it provides additional information regarding the position of the train, which can be used to supplement and update other position information, including GPS signals and for the cross-checking of a database. Still another object of the present invention is to provide information on the type of track change to a train passing through it. Yet another feature of the present invention is the verification of the relative speed, at which the intermediate tracks change from predetermined positions on one side of a locomotive, to a predetermined position on the other side of the locomotive. An advantage of the present invention will allow the train control system to determine the angle of a track change when it is passed. The present invention is a method and apparatus for controlling trains by detecting intermediate lanes between the traversed lanes, which are designed to meet the needs mentioned above, provide the objects set forth above, include the features listed above, and achieve the advantages already articulated. The invention is carried out in a "less ambiguous" system, in the sense that the ambiguity of the track is greatly reduced, providing information on the passage of the track changes, the angle at which the changes of via, and the direction taken by the train when it passes through the track change. Accordingly, the present invention is a method and apparatus for determining the presence and orientation of an intermediate path positioned between the tracks on which the train is traveling.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can be more fully understood by reading the following description of the preferred embodiments of the invention, in conjunction with the accompanying drawings, wherein: Figure 1 is a plan view of a parallel track configuration common that shows an entrance and two changes of track. Figure 2 is a block diagram of the train control system of the present invention. Figure 3 is an elevation view of a railway vehicle incorporating the sensors of the present invention, showing orientation of the sensors with respect to the rails on which the rail vehicle moves. Figure 4a is an elevation view of a rail vehicle of Figure 3, when it passes over a track change to the right and an intermediate lane located between the rails on which the rail vehicle moves. Figure 4b is an elevation view of a rail vehicle of Figure 3, showing the position of the intermediate rail corresponding to an intermediate position through a railway track change.

Figure 4c is an elevation view of a rail vehicle of Figure 3, which shows the intermediate rail on the opposite side, with respect to Figure 4a, which corresponds to a point along the railway track change to the right, which is near the end of the track change. Figure 5 is a diagram of the distance sensor of the present invention.

DESCRIPTION OF THE PREFERRED MODALITY Referring now to the drawings, in which similar numbers refer to similar matter through it, and more particularly to Figure 1, it shows a section of railway tracks designated in general as 100, they have, a first set of tracks 102 and a second set of tracks 104. Connecting tracks 102 and 104 are track changes 106 and 108. Also shown for discussion purposes, several positions along the tracks. Position A represents a position on track 102. Position B represents a position along track 102, which is positioned between track change 106 and 108, while position C represents a position on track 104. placed between the track change 106 and 108, and the position D represents a position along the track 102.

Also in Figure 1, segments 110 and 112 are shown, along with the heart of junction 116. AA, AB, and AC positions are also shown along tracks 102. Referring now to Figure 2 , there is shown an advanced train control system of the present invention, generally designated as 200, which would be located on the instrument panel of a locomotive (not shown). The system 200 includes a locomotive data radio 202, which is coupled to an antenna 204 and further coupled to an on-board computer 210. Also coupled to the on-board computer 210 is the GPS 206 receiver, which is coupled to a GPS antenna 208. Also attached to the on-board computer 210 is a wheel tachometer 212, an LCD screen 214, a LED appearance screen 216, a brake interconnect 218, and an ID module. of the locomotive 220. The radius 202, the antennas 204, 208, the GPS receiver 206, the wheel tachometer 212, the screens 214 and 216, the brake interconnection 218 and the locomotive ID module, are well known in The technique. The on-board computer 210 is preferably a computer using an architecture of P. C. The processor and the operating system and the other details are the object of the wishes of the system designer. The on-board computer 210 may include a broad railroad data base. Attached to the on-board computer 210, via line 223 is an input detector 222. The input detector 222 is described more fully in Figure 5 and its accompanying text. Now referring to Figure 3, there is shown a rail vehicle 300 of the present invention, which includes a first rail sensor 302 and a second rail sensor 304. The second rail sensor 304 is shown oriented in a direction toward the first rail 312, which is placed under the first wheel 322. The first sensor 302 is shown oriented in a direction towards the second rail 314, which is placed below the wheel 324. The rail sensors of this type, are of the general type that emits a signal and receives an echo of that signal reflected from the target. The distance to the target is determined by: Measuring the time it takes the signal to move to and from the target. Dividing the time measured between two, because the time measured was the round trip from the sensor to the target. Multiplying the travel time in one direction by the speed of the signal. For radar sensors based on light, the speed of the signal is the speed of light. For acoustic and ultrasound-based distance sensors, the speed of the signal is the speed of sound. The preferred embodiment of this invention uses a radar to measure the distance to the target. The preferred radar is a short-range, very low power device, known as a Micropotent Impulse Radar, as described in US Patents 5,361,070; 5,630,216; 5,457,394; 5,510,800 and 5,512,834, granted to Thomas E. McEwan and granted to the Regents of the University of California. The preferred radar implementation operates using very short pulses of Radio Frequency (FR) energy centered at 5.8 GHz. This frequency is preferred to operate the radar because: This frequency band is currently available for low power devices to operate without a license from the FCC. The wavelength of a signal in this band is approximately 5.2 centimeters, which is small compared to the size of the target. (Low-frequency operation would result in longer wavelengths in length, than the size of the lens with significantly reduced reflection and resolution).

The frequency is low enough not to be affected significantly by environmental conditions, such as rain and snow. A radar is preferred over the other sensor technologies, because it is less susceptible to environmental conditions, such as rain, snow, dust, etc. Acoustic and ultrasonic sensors are also affected to a lesser degree by temperature, barometric pressure and humidity. These acoustic and other sensors are well known in the art and are discussed in U.S. Patent 5,603,556, issued to Douglas D. Klink and awarded to Technical Services and Marketing, Inc. In this invention, two railway sensors are shown to improve reliability of the system, since they are part of a train safety system. Although it is possible to implement this invention with a single rail sensor, having two sensors provides the following advantages: The "third rail" coming from the main rail is detected by the rail sensor on the opposite side of the rail, before it enters the visual field of the rail. rail sensor, directly on the start of the track change, providing a faster response system. With only one rail sensor, the detection time depends on the direction taken through the track change.

Two rail sensors reduce the probability of false alarm. A rail sensor will detect the "third rail" approaching it, followed by the other rail sensor suddenly detecting the "third rail", much closer than the normal target and moving away from it. Distance data from railway sensors can be evaluated in a differential mode to increase the reliability and cancel any residual environmental effects, which are common to both railway sensors. The two rail sensors provide redundancy for greater total system reliability. It is believed that the preferred method for pointing or orienting rail sensors 302 and 304 is to direct the energy emitted from rail sensors 302 and 304 to the concave sections of lanes 314 and 312, as shown in Figure 3. The technique of Precise orientation is preferred as follows: a 60 ° cone of radiant energy is emitted over the center or sight glass, being directed to the center of the inner curved surface of the rail, between the head of the rail and the base of the rail, for a inside the lane and immediately adjacent to the lane on the opposite side of the locomotive.

Referring now to Figure 4a, there is shown a rail vehicle 300 of Figure 3. As also shown in Figure 4a, an intermediate rail 410 is located adjacent to rail 314. This configuration of the rails, including the first lanes 312 and 314 and intermediate lane 410, represents the view from the front of a locomotive traveling through track 102 in a direction from point A to point B when the locomotive passes track change 106. The position of the intermediate track 410 corresponds to the position of the track 110, as would occur in the AA position along the track 102 of a locomotive traveling from point A to point B, along the track 102. Referring now to Figure 4b, there is shown a rail vehicle 300, which shows an intermediate lane 410, placed between lanes 314 and 312. Lane 410 would correspond to lane 110 in position AB when a vehicle the railway moves from point A to point B, along track 102 of figure 1. Referring now to figure 4c, it shows a view of rail vehicle 300, as it would appear when the vehicle approaches to point AC of Figure 1. Intermediate rail 410 is shown positioned adjacent rail 312.

In Figures 4a, 4b and 4c, lanes 312 and 314 would correspond to track segments 112 and 114 of Figure 1. Referring now to Figure 5, there is shown a simplified block diagram of the input detector 222 of the present invention. The input detector 222 may contain a rail sensor 302 or other known distance sensors. Preferably, the output of the signals from the railway sensor 302 are processed by the signal processing circuit 502, which transmits information on the line 223 to the on-board computer 210 of Figure 2. It should be understood that the processing function of signals could be effected centrally by the computer 210 or at least partially distributed to the input detector 222. In a specific embodiment, the rail sensor 302 is a type of radar. A type of rail sensor 302 tested, is a Micropotence Impulse Radar Rangefinder from Lawrence Livermore National Laboratories. The preferred scan speed of that type of radar for use is 38 cycles per second. A sample rate as low as 20 cycles per second can be used.

In a preferred embodiment, the detector 222 has a strong preference for accepting the first return it could receive. In an embodiment using a radar rangefinder, an automatic gain control was added to the detector. This was done to compensate for the fact that the amplitudes of the rail reflections have considerable variations. These variations can occur due to the misalignment between the radar and the rail, which can cause the reflection to scatter. A minimum threshold was added to a constant fraction discriminator that was used to detect the leading edge of the reflection in the Exploration A output and chronologically record the pulse to a lower state. The minimum threshold stop eliminates spurious reflection signals and leakage signals. A first reflection capture can be added to keep the radar fixed in the lane. Special antennas can be used to reduce leakage and optimize specific mounting. The signal processor in a specific embodiment may comprise a single onboard 486 computer, with a PCMIA solid state disk of 6 megabytes. In another embodiment for use in more economical applications, the signal processor may be an 8-bit computer with sufficient random access memory to store a sample register and read-only memory, sufficient to store signal processing programs and threshold limits. . In operation, and referring now to Figures 1 to 5, a determination of the locomotive's pitch on a track change and the direction of travel through the track change, as well as the angle of the different track changes, can be determined as follows: A locomotive 300 travels along the track 102 from point A to point B, passes the track change 106, assuming that the locomotive goes directly through the change of track 106 and proceeds along the track 102 to position B. When the locomotive is in position A of Figure 1, the wheel and rail configurations, as seen from the front of the locomotive, looking in a direction towards the rear part of the locomotive, will be described by Figure 3, in which there are no intermediate lanes between lanes 312 and 314. When the locomotive enters the change of lanes 106, the lanes of lane 104 begin to appear. In the AA position, the front view would be described by Figure 4a. When the locomotive passes through position AB, the view from the front of the locomotive would be shown as in Figure 4b. Similarly, Figure 4c would describe the view from the front looking up to the back of the locomotive as it passes or approaches the point AC. The sensors 302 and 304 are capable of detecting the presence of the intermediate rail 410 when their relative position with respect to the rails 312 and 314 changes when the locomotive 300 passes through the track change 106. If the speed of the locomotive is known, either by wheel tachometer information, GPS or other means, then the speed at which lane 410 seems to move between lanes 312 and 314, will be indicative of the angle of the respective lanes 102 and 104. With high-speed trains, the switching angle from one track to another is at a lighter angle, and, therefore, a different track change is used. Given the known speed of the locomotive and the measured speed at which the intermediate rail moves between lanes 312 and 314, the on-board computer equipment can determine the angle of the track change and determine the type of track change that can be made. help determine the exact location of the track change that has been found. Additionally, the direction of relative movement of the intermediate rail will indicate, from which direction the locomotive comes through the change of track. For example, if the locomotive moves on track 102 in position A, where it must change track over track 104 in the change of track 106, and proceed to point C, then the middle lane would appear in point AA on the opposite side and would appear to move in a direction opposite to that described above for a train moving directly from point A to point B. In the situation where the train is moving from A to C, the view at point AA it will be represented by Figure 4c, which would proceed through Figure 4b at point AB, and would result in a view like the one shown in Figure 4a, when the locomotive passes through point C. In operation, and referring now to the Figures, the input detector 222 of the present invention works closely with the on-board computer 210, the GPS receiver 206, and a track database, which can be included in the on-board computer 210 or locate in a central location and coupling to the system 200 through the data radio of the locomotive 202. The GPS receiver 206 provides information of the current position and together with the on-board computer 210 and the track database, can predict when a train approaching a track change or other characteristic of the track. These predictions can be used to initiate the input detector 222 in a verification mode or, in an alternative mode, the input detector 222 can be in continuous operation, but the prediction of the position of the track operated by the GPS can be compared with the output of the input detector to determine precisely when a track change or other characteristic of the track has been passed. In some situations, the on-board computer 210 may be warned of the possibility of passing a feature of the track to which, in other circumstances, it could be interpreted as a third lane normally associated with a track change. For example, when a train crosses a highway in a level crossing, pavement or other materials usually placed between the lanes to provide a more secure and uniform crossing of the lanes by automobiles. The presence of this material could, in other circumstances, "confuse" the input detector 222. However, when the input detector 222 works closely with the GPS receiver 206 and the on-board computer 210, in conjunction with the database of tracks, this information can be used to confirm that the train has crossed a level crossing. Similarly, the input detector 222 can detect the passage of certain railway bridges, and this information can also be used to accurately confirm the position of the train. It is thought that the method and apparatus of the present invention will be understood from the foregoing description and it will be understood from the foregoing description that it will be apparent that various changes may be made in the form, construction, steps and arrangement of the parts and steps of the same, without departing from the spirit and scope of the invention or sacrificing all its material advantages. The form described herein is a preferred or exemplary embodiment thereof. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (20)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. An apparatus, on board a railway vehicle, of the type used for use on a first rail and a second rail, in which the first rail and the second rail are substantially parallel, the apparatus for assisting the control of the train, characterized in that it comprises : a first railway detector on board the railway vehicle, to detect the presence of a third rail positioned between the first and second rail and below the rail vehicle, the first rail detector generates a third rail detection signal; and, a device coupled to the first rail detector for receiving the detection signals from the third rail of the rail detector and analyzing the predetermined characteristics of the detection signals of the third rail. The apparatus according to claim 1, characterized in that it also comprises: a second rail detector on board the rail vehicle, for detecting the presence of the third rail placed between the first rail and the second rail and below the rail vehicle, the second rail detector for generating a second detection signal of the third rail; the device for receiving the first detection signals of the third rail of the first rail detector, for receiving, in addition, the second detection signals of the third rail of the second rail detector and analyzing the predetermined characteristics of the first and second detection signals of the second rail detector; third lane The apparatus according to claim 2, characterized in that the rail vehicle has a first side and a second opposite side and the first rail detector is placed on the first side of the rail vehicle and the second rail detector is placed on the rail side. second side of the rail vehicle. The apparatus according to claim 3, characterized in that the predetermined characteristics of the first and second lane detection signals are indicative of the direction of relative movement of the third lane with respect to the first lane and the second lane. The apparatus according to claim 4, characterized in that the device for receiving the first and second detection signals of the third rail further analyzes a characteristic of the first and second detection signals of the third rail, which are indicative of the relative speed at which the third rail moves with respect to the first rail and the second rail when the rail vehicle travels along the first rail and the second rail. The apparatus according to claim 1, characterized in that the first rail detector on board the railway vehicle is a radar. The apparatus according to claim 1, characterized in that the first railway detector on the railway vehicle is an optical detector. The apparatus according to claim 1, characterized in that the first railway detector on the railway vehicle is an acoustic sensor. 9. The apparatus according to claim 1, characterized in that it also comprises a GPS receiver and a data radio. 10. An apparatus for being used to control a railway vehicle of the type traveling on a first fixed rail and a second rail; the apparatus is characterized in that it comprises: means for measuring a distance from a predetermined position on the rail vehicle to a third rail placed between the first rail and the second rail, and for generating a third distance signal from the rail; and means for verifying the third lane distance signal to determine if changes occur in the distance signal with time, when the rail vehicle is moving along the first lane and the second lane. 11. The apparatus according to claim 10, characterized in that the means for measuring a distance from a predetermined position on the rail vehicle to a third rail, is a low power radar. 1

2. The apparatus according to claim 10, characterized in that the means for verifying the distance signal of the third rail comprise a multipurpose computer on board the railway vehicle. The apparatus according to claim 10, characterized in that the means for verifying the distance signal of the third rail is a dedicated microprocessor to be used in association with the means for measuring a distance from a predetermined position on the rail vehicle to a third one. lane. The apparatus according to claim 10, characterized in that the means for verifying the lane distance signal includes a data radio and a computer processor, located far from the railway vehicle. The apparatus according to claim 11, characterized in that it also comprises second means for measuring a distance from a second predetermined position on the railway vehicle to a third rail placed between the first and second rail and for generating a second signal away from the third lane. 16. The apparatus according to claim 15, characterized in that it further comprises a GPS receiver coupled to the means for verifying the distance signal of the third rail to provide position information of the rail vehicle, when the rail vehicle progresses along of the first lane and the second lane. The apparatus according to claim 16, characterized in that it further comprises a radio coupled with the means for verifying the lane distance signal, for generating a signal to a remote location containing information related to the position information of the lane. railway vehicle. 18. A method for controlling a railway vehicle of the type traveling on a first rail and a second rail, the method comprising the step of: transmitting a predetermined signal having predetermined signal characteristics, from a predetermined position on the railway vehicle; receiving the reflected signals and determining a time interval between when a last signal was transmitted and a first signal is received, which has predetermined signal strength characteristics; determining a distance from the predetermined position on the railway vehicle to a third lane located between the first and second lanes, using such a time interval; affect the operation of a rail vehicle in response to the determination of distance. The method according to claim 18, characterized in that the transmission step comprises generating and transmitting a low power radar signal. The method according to claim 18, characterized in that the steps of transmitting, receiving and determining are repeated during a predetermined time interval.