The present invention generally relates to railroad placement and surfacing. More particularly, the present invention relates to a method and system for controlling such railroad surfacing. The control system of the present invention can be used in conjunction with existing surfacing systems.
When constructing a railroad, after properly grading the underlying land, a bed of gravel or ballast is formed from anywhere between one and three feet thick. The railroad ties are embedded in the ballast and the rails attached thereto. In the case of wooden railroad ties, the rails are nailed to the ties with spikes. In the case of concrete ties, clips connect the rails and the ties.
The rails and ties must then be set at a predetermined height and alignment. The rails must be a certain height above the ballast and stay within pre-set tolerances with respect to alignment.
A machine, often called a ballast tamper, is used to lift the rails and ties and vibrate the gravel ballast such that the ties can be set at the proper depth and the rails aligned. Survey points or stations established during the design of the rail track are used to determine what the position and depth of the rail and railroad ties should be.
Over time, the railroad must be maintained as the gravel and ballast sink into the ground. Such sinking is not constant through the length of the railroad. Accordingly, the tamper machine must be utilized to periodically lift and realign the rail and railroad ties and either vibrate the existing gravel into place, or vibrate new gravel into place to properly set the ties and rails.
In the past, a buggy having infrared projectors was moved to no more than 100 feet away from the tamper machine on what was considered “good track” and projected infrared beams to sensors positioned on the machine. A shadowboard on the machine cooperatively worked with the infrared projector and sensor to determine proper alignment between the projector and sensor, and thus proper alignment and position of the rails and tracks. This is commonly referred to as a shadowboard system.
However, the current method of “tamper” or surfacing the rails and railroad ties using the existing shadowboard system leaves much to be desired. First, the buggy must be placed no more than 100 feet in front of the machine. Thus, every 100 feet the buggy must be repositioned. According to the survey station reference point or marker data, at least one individual moves a surface or vertical projector, as well as a horizontal or line projector, to the proper position. This may require manually moving the projectors to the desired point. In some cases, the projectors are positioned at the end of a tube or rod which can be moved horizontally or vertically using hydraulics or motors or the like. An operator at the tamper machine must move the shadowboards and/or sensors until the proper alignment is achieved, wherein the shadowboards block the infrared beam from the projectors. At least two or three individuals are required to operate the existing shadowboard system. The existing shadowboard system is also very difficult to use when the rail has vertical or horizontal curves or dips. In fact, it can take an average of three passes of the tamper machine to set the rails within the required tolerances. This is particularly the case when there are dips in the rails as the infrared projectors shoot their signals over the sensors. As the buggies with the projectors are typically between 50 and 100 feet in front of the tamper machine, there is a built-in error in the correction to the rails. For example, in the case when the buggy and projectors are positioned approximately 100 feet from the tamper machine, and assuming there is approximately a 15 feet spacing between the shadowboards and the sensors, there is an approximately 7:1 error correction ratio. Thus, if the projector is within a seven inch depth of track of the tamper machine, the tamper machine will create a one-inch depth from the desired height. Thus, the tamper machine must pass and lift the rails at least two or three times before the rails are of the sufficient height that the projectors can communicate with the infrared receivers on the tamper machine before the shadowboards come into alignment and indicate that the rail is set at the proper tolerance level. Once the tamper machine has lifted and aligned the rails to the desired position, typically after multiple passes, the buggy must be positioned uptrack of the tamper machine and the projectors manually positioned, as described above.
As such, only approximately 800 feet per day can be surfaced using the existing shadowboard system and tamper machines. Moreover, the existing shadowboard systems are not extremely accurate and thus make the surfacing or tampering of commuter rail lines, which have much tighter tolerances, very time consuming and costly.
Accordingly, there is a need for enhancing the existing railroad surfacing systems such that greater accuracy is achieved, the number of passes by the ballast tamper machine is reduced, and the feet per day of surfacing is greatly improved. What is also required is a system which is capable of guiding the ballast tampering machine to create vertical and horizontal curves. The present invention fulfills these needs and provides other related advantages.
The present invention resides in a railroad rail surfacing control system, which can be used in combination with existing shadowboard systems. The system and method of the present invention improves resurfacing accuracy and efficiency such that the rails can be set within the necessary tolerances in automatic fashion in as few as a single pass. Thus, many more feet per day can be surfaced than using existing technology. Moreover, the method and system of the present invention allows vertical and horizontal curves to be automatically resurfaced.
Generally, the method for controlling the railroad surfacing in accordance with the present invention includes imputing desired railroad rail position values into a controller. Railroad rail position correction values are determined by comparing the desired railroad rail position values with actual railroad rail position values. The railroad rail is moved to the determined correction value position using a railroad tamper machine, which is operably associated with the controller.
In one embodiment, the inputting step includes the step of inputting a table of desired railroad rail position values for a predetermined length of railroad track into the controller. The position of the tamper machine with respect to the length of the railroad track is determined. A reference signal may be obtained from a transmitting device associated with a known marker in relation to the position of the tamper machine on the railroad track, which corresponds to a desired railroad position value. The tamper machine then automatically corrects the rail position using the table of desired railroad rail position values and reference signal.
In another embodiment, the reference signal from a transmitting device is used. A reference signal receiver is in communication with the controller, and the controller moves a shadowboard system projector a distance corresponding to the railroad rail correction value. The shadowboard system projector is disposed uptrack of a shadowboard and sensor of the tamper machine. In a particularly preferred embodiment, the reference signal receiver and shadowboard system projector are mounted on a buggy coupled to a front of the tamper machine.
In one embodiment, the reference signal is transmitted by at least one laser device positioned uptrack of the tamper machine. The laser device is disposed relative to a known survey marker. The laser device transmits a surface laser reference signal and a line reference signal to provide desired vertical and horizontal railroad rail position values. Typically, a first laser transmits a surface laser reference signal, while another laser transmits a line laser reference signal. Laser receivers associated with line and surface projectors receive the respective laser signals. The controller interprets the signal and moves the line or surface projectors a correction distance.
In another embodiment, the reference signal is transmitted by a GPS transreceiver positioned relative to a known survey marker. The GPS transreceiver is adapted to receive GPS signals from satellites, and transmits a reference signal to a reference signal receiver associated with the line or surface projector. The reference signal receiver comprises a GPS antenna receiver in communication with the controller for moving the projector, as needed.
An interface unit is preferably disposed within the tamper machine cab. The interface unit includes a display for displaying values corresponding to a desired railroad rail position and actual railroad rail position. The interface unit is adapted to permit the tamper machine operator to manually make railroad rail position corrections and deviate from the desired railroad rail position as necessary.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in connection with the accompanying drawing which illustrate, by way of example, the principals of the present invention.
The accompanying drawings illustrate the invention. In such drawings:
As shown in the accompanying drawings, for purpose of illustration, the present invention resides in a system and method for controlling railroad surfacing. As will be more fully discussed herein, the system and methodology of the present invention enable the automatic adjustment of the rails of the railroad track with little or no operator intervention. Proper railroad surfacing can be achieved in as little as one pass by a tamper machine by as few as a single worker. Moreover, as will be more fully discussed herein, the length of railroad track which can be adjusted and resurfaced per day is greatly increased in comparison to existing methods.
With reference now to
In various embodiments of the present invention, the existing “shadowboard” is implemented. However, as illustrated in
With continuing reference to
With reference now to
As mentioned above, in the laser control system of the present invention, a line or horizontal reference signal can be generated and received as well. With reference to
A scope 42 or other alignment device is used to align the laser signal with a line laser signal receiver 44 positioned on the trolley 14 and associated with a line projector 46, as illustrated in
With reference now to
Preferably, as illustrated in
An electronic and operational diagram of the system is shown in
With reference now to
As illustrated in
With reference now to
With particular reference to
At the tamper machine 10, GPS signal reference receivers, in the form of GPS antennas 66, are associated with the projectors 16 and 46, similar to the laser reference signal receivers 28 and 44. These receivers 66 also receive positional data from the satellite 64. However, as discussed above, this positional data can be off by a fraction of an inch or even more. Thus, transreceiver 62 emits a correction signal 68 to the antenna 66. This signal 68 indicates, for example, that the positional data from the satellite 64 is in error 0.1 feet. This information is provided to the controller 30, which then calculates and determines the desired rail position, and moves the projectors 16 and 46 accordingly. As discussed above, movement of the projector 16 or 46 causes the tamper machine 10 to raises the rail 12, or move them left or right according to the existing shadowboard system methodology.
Referring again to
Thus, the operator of the tamper machine 10 is able to select between a variety of modes. First, a standby mode can be selected wherein the conventional projector and shadowbox system is used instead of the precision referenced signals from either the laser or GPS equipment. Alternatively, the automatic laser mode can be selected and the tamper machine 10 controlled by the controller 30. As another alternative, when using GPS equipment, the tamper machine 10 is controlled by the control 30 which responds to the received GPS information. In either of these modes, the operator can select manual mode for either the surface and/or line rail positioning.
Although the projectors 16 and 46 and receivers 28, 44 and 66 have been described as being placed on a tamper buggy 14 coupled to the front of the tamper machine, it will be appreciated that these components could be incorporated onto or into the tamper machine 10 itself. Thus, the electronic circuitry of the controller 30 could be incorporated into the tamper machine 10, and the laser signal or GPS signal receivers coupled to the tamper machine 10 and movable with the projectors 16 and 46 on the tamper machine 10 itself. However, as most existing railroad surfacing operations already include a tamper buggy 14 with projectors 16 and 46, the laser signal receivers 28 and 44 or GPS antenna 66, as well as a controller 30, are typically positioned on the buggy 14 for convenience sake.
It will be appreciated that the aforementioned embodiments of the present invention provide significant advantages over the traditional railroad surfacing systems and methodology. Whereas the projector buggy 14 could be placed no more than 100 feet in front of the tamper machine 10 on “good track”, with the projectors 16 and 46 manually moved into position, the laser-based system of the present invention enables the laser transmitters 24 and 36 to be placed approximately 500 feet from the tamper machine 10. Moreover, these transmitters are referenced to a known survey marker.
Further, the projectors 16 and 46 are automatically moved as the tamper machine 10 progresses along the rails 12. The coupling of the buggy 14 to the tamper machine 10 also significantly reduces the correction error. Thus, a single operator can use the laser-based system of the present invention to precisely correct approximately 2,000 feet of rail in one day, instead of requiring two or three operators to surface approximately 800 feet per day. Using the GPS-based system of the present invention, a single operator can precisely position approximately 4,000 feet of rail per day. This increase is largely due to the fact that the reference data of the known survey marker need only be established and calibrated once per day using the GPS system. The laser-based system must be recalibrated and new survey markers approximately every 500 feet. The existing shadowboard system must be recalibrated approximately every 50 to 100 feet and multiple passes are often required to fully correct the track.
The railroad surfacing system of the present invention is also useful in that it provides the ability to pre-program both horizontal and vertical curves, and also to use a slope laser for vertical curves. This enables curve railroad surfacing to be done in one or two passes, instead of the arduous process of repeatedly passing over curves, as is presently done. In this curve surfacing mode, the tamper operator enters a table or list of desired rail position values, including station number or survey marker numbers and values and offset values. This is typically done using a hand-held device 71, which communicates with the controller 30. These values are stored in a PLC of the controller 30. The tamper operator then switches the system to the appropriate auto-curve mode. Functionally, the operator enters a series of “station numbers” for offsets to occur. The station numbers are specific survey points used to initially set the track. Station numbers are typically eight-digit numbers that can be either in feet or centimeters. The user then inputs a starting station number, direction of travel (station numbers going up or down) and “calibrates” the distance wheel 58 to that value. At each “station number” the operator can input offset values for the surface projector, surface laser receiver, or line projector. Between stations, the offset is calculated as an offset value per foot moved. The tamper machine operator can review and/or modify entries from the hand-held data entry terminal on the touch screen panel interfacing 32 in the tamper cab. An additional motorized device 72 is utilized to move laser receiver 28 independent of device 34 so that curve tangency and slope data can be incorporated into the automatic movement of projector 16. The operator does not need to make any adjustments to the projectors while working through the curve. Instead, the laser receivers and tamper projectors are automatically moved to correspond to the values previously entered along the curve as the tamper machine 10 moves. Vertical curve surfacing can also be performed under the laser control. Of course, those skilled in the art will realize that the curve mode could also be performed using the aforementioned GPS system.
It is also contemplated by the present invention that known survey marker point values, also referred to as stations, can be entered into the hand held device 71, and the GPS or laser precision signals used merely as reference signals, the tamper machine 10 automatically correcting the rail position to the desired rail position based upon the information input in the list or table of survey marker positions and information. Thus, even relatively straight or flat sections of rail 12 could be corrected according to the pre-programmed and input listing of desired values. Instead of entering the survey marker or station values, exact values of the rail positions, at any given point along the railroad track could be entered into the hand held device 71, which could control the tamper machine 10 operation with or without GPS or laser reference signals. Actual rail position values are compared with the input desired rail position values, and a corresponding correction made either vertically and/or horizontally to the rails to move them into the desired position or within acceptable tolerance levels.
Those skilled in the art will readily appreciate that the present invention provides many advantages over existing railroad surfacing systems. The present invention provides a high degree of precision and speed when laying new track or surfacing existing track. Simultaneously, the time required for surfacing is decreased, as the track can typically be precisely laid or positioned in only one or two passes. Instead of requiring two or three workers, the present invention requires only one or two workers, presenting a significant reduction in labor costs for surfacing operations. Maintenance costs of the surfacing equipment is also decreased. Moreover, curves can be resurfaced and positioned very accurately in as few as a single pass.
Although several embodiments have been described in detail for purposes of illustration, various modifications may be made to each without departing from the scope and spirit of the invention. Accordingly, the invention is not limited, except as by the appended claims.
This application claims priority to U.S. Provisional Application Ser. No. 60/602,078, filed on Aug. 16, 2004.
Number | Date | Country | |
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60602078 | Aug 2004 | US |