Wayside measurement of railcar wheel to rail geometry

Considerable damage to rails, wheels, and trucks can result from geometric anomalies in the wheelsets, rails, and truck hardware. A solution for identifying and quantifying geometric anomalies known to influence the service life of the rolling stock or the ride comfort for the case of passenger service is described. The solution comprises an optical system, which can be configured to accurately perform measurements at mainline speeds (e.g., greater than 100 mph). The optical system includes laser line projectors and imaging cameras and can utilize structured light triangulation.

TECHNICAL FIELD

This disclosure relates generally to the field of rail transportation, and more particularly, to determining a condition of a railcar wheelset and/or truck that may indicate an unsafe condition of the railcar wheelset and/or truck.

BACKGROUND ART

In railway service, rails are nominally parallel with a known elevation and a known cant with respect to a horizontal plane. Railcar wheelsets are mounted in pairs on a suspending device referred to as a truck (also called a bogie). Minimum wear on components and maximum ride comfort occurs when the wheelsets are centered on the rail with axes of rotation perpendicular to the rail centerline; any deviation from this alignment and orientation introduces vibration and results in increased wear.

Several basic measures of misalignment have been related to reduced component life and ride comfort, including angle-of-attack (AOA), tracking position (TP), shift, inter-axle misalignment, and rotation. A primary measure, AOA, is defined, from a measurement point of view, as the angle between the plane containing the rim face of a railcar wheel and a tangent line to the rail on which the wheel is engaged. TP is defined as the transverse displacement of the centerline of the wheelset from the centerline of the rail pair. Additional derived measurements related to AOA and TP are made to identify particular anomalies that have been correlated to reduced component life and ride comfort. The measurements assess the translational and rotational misalignments between the two axles on a truck, and between the axles and the rails. Finally, hunting is a term describing periodic transverse motion of the railcar on the track that may, in severe cases cause resonant oscillation, which results in the wheel flanges impacting the rail. This condition can result in rapid component wear and serious ride comfort issues. Serious truck geometry errors can even result in derailment, especially when operating at high speed and when cornering, causing considerable damage and potential loss of life. Thus an accurate and timely measurement of truck alignment errors can result in reduced maintenance costs and possible prevention of catastrophic derailments.

In general, two technologies have been applied to measure truck related geometry anomalies. In a first approach, strain gauges are mounted to the rail to measure the vertical and lateral forces. In this approach, the ratio of the lateral force to the vertical force is indicative of wheelset misalignment. Such a system, however, requires expensive and time consuming changes to the track infrastructure. For example, installation of strain gauges on a track typically requires grinding the rail and the placement of concrete sleepers to properly support the section of track for accurate strain measurement. If the instrumented rail sections are changed out, the system functionality will be lost.

In a second approach, a wayside optical system comprising a laser beam and an optical detector in conjunction with a wheel detector is used to make the measurements using the principle of optical triangulation. In this case, a point laser displacement measure device is used, which may measure 10,000 points/sec on the field side rim face of a passing wheel.

Unfortunately, this approach is only robust for new, good-condition wheels. In particular, the laser is typically applied at an elevation of approximately one inch above the rail. For good-condition wheels, this allows a continuously measurable section of rim face of about ten inches (or at 10 k points per second at 60 mph, about 110 points). However, as the wheel wears, the rim face becomes more and more narrow, resulting in two separated measurement regions which become smaller as the wheel continues to wear. For the worst case of a condemnable wheel, only 5 data points will be produced for a train speed of 60 mph. As the corners of the rim face may be contaminated with debris, dirt, snow, ice, or the like, inconsistent measurements may result, especially in the case of the more worn wheels for which the measurements have less redundancy to allow for the elimination of outliers.

Another significant limitation of this approach derives from the fact that the measured points are in a time-sequence along a moving object. As there are modes of movement of the wheels in which the alignment of the wheel will vary throughout a complete revolution, this method of measurement may be confused or at least rendered less accurate through variations in the wheel orientation over time.

In a variant of the second approach, proximity sensors, such as inductive sensors, are attached to the rail to measure the duration and relative timing of the signal generated by the passing wheels. By employing two sensors, one on each rail, the angle of attack and other truck performance parameters may be measured. This approach is sensitive to the diameter, speed, and condition of the surfaces of the wheel at the point of detection. In particular, proximity sensors are known to have response variations to all of these conditions, and any variation in response can result in an incorrect measurement of the target parameters.

SUMMARY OF THE INVENTION

The invention described herein utilizes a wayside optical system to make truck alignment measurements in a way that can address one or more limitations and potential error sources in the prior art.

An embodiment can acquire all data required to make a measurement simultaneously (as opposed to over a period of time) to eliminate errors associated with wheelset transverse and/or angular motion that may occur when measurements are made over a more extended period of time.

An embodiment can provide, within the acquired data, a reference to the rail tangent line, reducing the need for labor intensive alignment and calibration procedures at installation and periodically during operation.

An embodiment can acquire sufficient data points over an extended portion of a wheel so as to be insensitive to isolated surface anomalies that may be present on the wheel due to normal use.

An embodiment can mitigate the effects of the wake of dust/snow that may result from a train passing at high speed.

An embodiment can prevent accidental injury to the eyes of railway maintenance personnel or other persons that may be in the path of the operating invention by utilizing laser power levels classified as eye safe under all conditions.

A first aspect of the invention provides a system for evaluating a railcar wheelset for rail alignment, the system comprising: a plurality of structured light measuring devices configured to measure a set of features of opposing wheels on the railcar wheelset as the wheels travel along a rail, a structured light measuring device including: a set of laser line projectors configured to illuminate a portion of a wheel rim surface of a wheel and a portion of a rail head surface of the rail with a sheet of light having an orientation which is substantially vertical and orthogonal to the rail; and a high speed camera configured to acquire image data of the laser light scattered by the wheel and rail; means for automatically determining when to acquire the image data using at least one of the plurality of structured light measuring devices and automatically activating the at least one of the plurality of structured light measuring devices; and a computer system configured to process the image data by performing a method comprising: forming Cartesian coordinates of a plurality of image data points on the wheel rim surface and the rail head surface; and converting the Cartesian coordinates into a plurality of wheel alignment measures, wherein the plurality of wheel alignment measures include an angle of attack and a tracking position.

A second aspect of the invention provides a method for evaluating a railcar wheelset for rail alignment, the method comprising: projecting a plurality of laser lines substantially vertical and orthogonal with respect to a plurality of rails, wherein the projecting is configured such that each of the plurality of laser lines illuminates a portion of a rim surface of a railroad wheel of the railcar wheelset as the wheelset travels along the plurality of rails and a portion of a corresponding rail of the plurality of rails, and wherein at least two laser lines illuminate at least two distinct portions of the rim surface of each of the plurality of railroad wheels of the railcar wheelset; acquiring image data for the plurality of railcar wheels during the projecting; processing the image data to at least one of: reduce noise in the image data or remove outlier points from the image data; for each of the plurality of railroad wheels: deriving three dimensional space coordinates of a plurality of image data points corresponding to the at least two distinct portions illuminated by the laser lines using the processed image data; fitting a plane to the three dimensional space coordinates; comparing an alignment of the fitted plane with a plane of the corresponding rail; and determining whether the alignment of the fitted plane is within an acceptable variation parameters for wheel alignment with the rail; and determining whether any of a set of wheelset alignment conditions is present based on the wheel alignment for each of the plurality of wheels of the wheelset.

A third aspect of the invention provides a system comprising: an imaging component located adjacent to a location of a pair of rails, wherein the imaging component includes a plurality of structured light measuring devices configured to concurrently acquire image data for opposing wheels on a railcar wheelset as the wheels travel along the pair of rails, a structured light measuring device including: a set of laser line projectors configured to illuminate at least two distinct portions of a wheel rim surface of a wheel and a corresponding at least two distinct portions of a rail head surface of the rail with a sheet of light having an orientation which is substantially vertical and orthogonal to the rail; and a camera configured to acquire image data of the laser light scattered by the wheel and rail from both of the at least two distinct portions; and a computer system configured to process the image data by performing a method comprising: for each of the opposing wheels: deriving three dimensional space coordinates of a plurality of image data points corresponding to the at least two distinct portions illuminated by the laser lines from the image data; and fitting a plane to the three dimensional space coordinates; and calculating a plurality of wheel alignment measures for the railcar wheelset, the wheel alignment measures including an angle of attack and a tracking position.

Other aspects of the invention provide methods, systems, program products, and methods of using and generating each, which include and/or implement some or all of the actions described herein. The illustrative aspects of the invention are designed to solve one or more of the problems herein described and/or one or more other problems not discussed.

DETAILED DESCRIPTION OF THE INVENTION

As indicated above, aspects of the invention provide a solution for identifying and quantifying geometric anomalies known to influence the service life of the rolling stock or the ride comfort for the case of passenger service. The solution comprises an optical system, which can be configured to accurately perform measurements at mainline speeds (e.g., greater than 100 mph). The optical system includes laser line projectors and imaging cameras and can utilize structured light triangulation. As used herein, unless otherwise noted, the term “set” means one or more (i.e., at least one) and the phrase “any solution” means any now known or later developed solution.

Turning to the drawings,FIG. 1illustrates wheel to rail geometry showing the angle of attack. InFIG. 1, a wheel20is attached to an axle22. The wheel20has key components including a tread24, a flange26, a field side28and a gauge side30. The wheel20runs on its tread24on rail32. The rail includes a rail head or top34and a rail base36. The rail head34and rail base36are connected by a “web” section which is not visible inFIG. 1.

In any event, a set of wheels20and rails32are designed such that during normal operation the axis of rotation38(nominally the centerline of the axle22) of the wheel20is nominally perpendicular to the centerline40of the rail32. Maintaining this geometry minimizes wear and operational drag between the components. As the axle22and wheel20are rigidly connected (unlike in many other vehicles, such as passenger cars) and thus wheels20at either end of the axle22cannot turn independently, any misalignment will cause at least some drag rather than turning of the wheels. Sufficient angles of misalignment could cause direct friction between the wheel flange26and the railhead34.

Therefore, in normal operation, the field face28and/or gauge face30will have a nominally parallel facing to the centerline40of the rail32, as illustrated by line42. If a misalignment occurs, the face28,30of the wheel20will depart from this nominal position as shown by line44, producing an angle46. This angle46is known as the angle of attack or AoA. Ideally, the AoA46is zero. Industry sources state that it is desirable to detect changes in the AoA46by at most 0.2 degrees, and preferably less, and that the AoA46should never exceed three degrees.

FIG. 2illustrates an illumination and image capturing component according to an embodiment. The component comprises a structured light measurement system70, which can include two structured light imaging units72. The structured light imaging units72themselves can include a high-speed imaging unit (camera)74and a laser line projector76. It is understood that this is only illustrative. To this extent, a structured light measurement system70can use different numbers of imaging units72, imaging units72of different design, and/or the like. For example, an imaging unit72can include more than one laser line projector76to project multiple lines, e.g., from different angles, within a field of view of the camera74. Cameras74may be any cameras capable of operating at a sufficient frame rate and sensitivity to acquire the images needed. For example, one acceptable selection for a camera74is the Stingray Model F-033, supplied by Allied Vision technologies, which is capable of operation at 366 frames/second for a region of interest of 656×60 pixels. However, it understood that this is only illustrative. The laser line projectors76may be any of many vendors' products which produce sufficiently sharp lines at a sufficient intensity.

FIG. 3shows a system view of an embodiment of the invention. The system comprises a component100including two structured light measurement systems70, which is affixed to the rails32, e.g., by a clamping support102or by other means known to those skilled in the art of railroad instrumentation. Two wheels20connected by an axle22are shown passing over the component100, riding on the top or head34of the rails. This combination of two wheels20on an axle22is called a wheelset. As the wheels20reach an appropriate point, the laser line generators76(FIG. 2) can project vertical sheets of light104at a nominally perpendicular angle to the rail32and gauge face30of the corresponding wheel20. The cameras74(FIG. 2) capture an image of a section of the wheel20, which is within the camera20's field of view106. The field of view106can be selected such that the vertical laser line(s)104is visible within the field of view106. In an embodiment, a separation of the laser lines104in a direction of motion of the wheel20is, for example approximately sixteen inches, to result in ideal imaging conditions for typical wheel diameters. The laser line generators76may use visible and/or near-infrared light with a power level appropriate for the imaging conditions. In many applications, a power level of approximately 100 mW would be appropriate.

The structured light measurement systems70must operate at the proper time to acquire useful images of the wheels20. In order to achieve this, a standard wheel switch108can be attached to the rail32at such a location that it can detect passage of the wheel20and trigger the structured light measurement systems70to obtain the images. While not shown, it is understood that another wheel switch108may be placed farther from the component100as a “wake up” trigger. This permits the structured light measurement systems70to effectively shut down when no trains are nearby, thus conserving significant energy.

In the basic configuration of an embodiment, simultaneous capture of images by cameras74is triggered by the wheel switch108. Due to the simultaneous acquisition of images, and the known geometry between the cameras74and lasers76, the speed and acceleration of the wheels20is not required and does not influence the measurement. The methods to obtain full 3-D measurement from the point cloud of laser line104points on the wheels20as imaged by the cameras74are those used for three-dimensional structured light metrology, e.g., as described in U.S. Pat. Nos. 5,636,026 and 6,768,551, both of which are hereby incorporated by reference.

Therefore, with three-dimensional planes determined for the gauge side30of the wheels20on both sides of the rail32, an alignment of these planes with the nominally parallel plane represented by the rail32can be evaluated, and any misalignment (angle of attack) can be measured accurately.

In an embodiment, multiple images may be taken by each camera74as the wheel20passes. If a wheel20is passing the component100moving at a speed of 100 mph (1760 inches/sec), and the camera74can capture366images per second, a properly timed triggering of the camera74will permit the capture of at least three usable images of the wheel20. This is illustrated inFIGS. 4a-4c. With the above numbers, it is clear that in the interval between each individual image, the wheel will move less than five inches.FIG. 4ashows the wheel20at the time of initial capture,FIG. 4bshows the wheel20at the point of the second image capture, andFIG. 4Cshows the wheel20at the time of the third image capture. If we assume the high-resolution axis of the camera74is oriented vertically and has a vertical field of view106(FIG. 3) that just encompasses the projected line104, a scale factor of approximately 100 pixels/inch is obtained. For each of the images captured in the conditions shown inFIGS. 4a-4c, at least 150 pixels will be visible on the rail32and anywhere from 100 to 350 pixels on the rim face30. Using features in the images, such as the rim break130, the approach remains insensitive to the speed or acceleration of the wheel20. The multiplicity of images covering the approximate sixteen inch linear distance on the rim face30and rail32, provides a high degree of insensitivity to local defects or contamination of the imaged surfaces. In addition, multiple images provide a method to detect other variations in wheel presentation. For instance, if the wheel20itself is twisted, there will be a clear and detectable change in the apparent AoA46(FIG. 1), while in the case of an ordinary AoA46(wheelset of two wheels20and an axle22being set slightly off their nominally parallel mounting) the AoA46remains generally constant.

An illustrative required measuring range from industry sources for the AoA46is +/−3°. Actual data indicates that the AOA46is less than +/−1.72° 98% of the time and less than 0.57° 95% of the time. An illustrative required measurement resolution is 0.2°. This information will determine the required camera resolution (in pixels) to achieve the desired measurement resolution. The structure angle (angle between the camera74line of sight and the laser76boresight) must be sufficient to allow the measurement to be made accurately. In an embodiment, the angle may be approximately 30°, although other angles may be used for specific effect. As the measurements will be made typically in an open outdoor environment, suitable filters, such as laser line band pass filters, may be utilized on the camera74to minimize the effect of stray ambient light on the measurement. The laser power can be selected to provide sufficient illumination on the rail32and wheel20to produce a usable image on the camera detector under all operational states of the surface of the wheel20and rail32.

An embodiment, of the invention can utilize image processing methods, such as median filtering and ensemble averaging, to reduce the effects of blowing snow or dirt that may be produced by a train passing at high speed. A standard rail heater, such as those from Spectrum Infrared, may be used to melt snow and ice that may be present up to the top of the rail32in certain climatic regions at certain times of the year. Raw data from the camera detectors can be processed to produce a multiplicity of centroids in image coordinates by methods taught in the art, e.g., as in U.S. Pat. Nos. 5,636,026, 6,768,551, and 5,193,120. The centroids can be converted into points in a Cartesian <x, y, z> coordinate system that is fixed with respect to the rail again using methods such as taught by U.S. Pat. No. 5,193,120.

A set of points that nominally lie in a vertical plane can be obtained from all the images in <x, y, z> coordinates that were developed from the laser lines104projected onto the wheel's rim surface30. Standard statistical analysis can be used to identify any outlier points that may arise due to anomalies on the wheel surface, such as dings, dents, gouges, deposits, and/or the like. The remaining points can be fitted to a plane using mathematical methods known in the art. The same process can be applied to the image points on the camera detector resulting from the laser line projected on the rail32. The angle of rotation of the rim face plane about a vertical axis with respect to the plane from the rail head is the desired angle of attack (AOA). Using measurements taken on both wheels20of a wheelset combined with the known geometry of the two systems70, the following measurements can be made. A complete set of the first two measurements can include measurements for the leading (L) and trailing (T) wheelset in the pair, which can be subsequently used for one or more additional measurements:Angle of attack (AOA)—orientation of the axle22relative to the tracks32, which can be measured in millradians;Tracking Position (TP)—position of the wheelset relative to the track centerline40(FIG. 1), which can be measured in mm;Inter-axle misalignment—orientation of both axles22of a truck in relation to each other, which can be defined as AOAL-AOAT;Tracking Error (TE)—difference in tracking positions of the truck axles, which can be defined as TPL−TPT;Truck rotation—evaluation of steering ability of the truck, which can be defined as (AOAL+AOAT)/2;Shift—axle shift with respect to the rail center line40, which can be defined as (TPL+TPT)/2; andBack to back—distance between rim faces30on opposite wheels20of a wheelset.
All the described measurements can be made with a single component100.

Hunting is another measurement/evaluation that may be desired. Hunting is the lateral instability of a truck measured as peak axle displacement over a defined distance and can shown in millimeters. Measurement of hunting requires a multiplicity, for example three, of the components100located along the rail32and separated by a fixed distance, for example, ten feet. The hunting amplitude and wavelength is developed from the TP measurement for each wheel20as it passes each of the components100, e.g., by fitting a sinusoidal curve to the TP data. In order to avoid aliasing, the components100can be disposed along the rail32such that at least three measurements occur within a single period of the hunting motion.

Hunting, as described herein, is a slow side to side motion of the wheelsets on the rail32.FIG. 5shows multiple views of a single wheelset150of two wheels20and an axle22passing by three components100. This wheelset150is “hunting” and the components100can be spaced approximately ten feet apart inFIG. 5. As the wheelset150travels along the rail32, it moves successively to one side—up, in the reference frame ofFIG. 5, transversely across the rail32—as more clearly shown by the lines152,154, and156. These lines152,154, and156correspond to the location of the gauge-side face30of one wheel20as it travels along the rail32and past each of the components100. The motion of the wheelset150is constrained by the wheel flange26, such that the wheelset150will then reverse its drift until stopped by the flange26of the wheel20on the other side of the wheelset150. These oscillations are “hunting” and generally occur over distances of ten feet or more.

An embodiment of the present invention, therefore, can detect and measure hunting by evaluating the distance the wheelset150moves from side-to-side across multiple spaced measurements.

To this point, the discussion of the component100has depicted the component100as including the imaging components70(FIG. 2) and a rugged casing. However, in actual use, the system can include additional devices to operate and perform the actions described herein.FIG. 6illustrates this in concept. The component100is shown including a rugged casing170, a data collection unit172, a power and control module174, and a communications module176.

The data collection unit172may comprise a computing device merely configured to gather the raw data and pass it to the communications module176for transfer to another computer system for analysis as described herein. However, the data collection unit172may also include data processing capabilities in hardware and be provided with software to perform some or all the analysis described herein on the data in real-time on location. In an embodiment, such hardware could be a focused image-processing system such as the Gumstix Overa™ line, a PC-104 based board computer, or any other hardware solution appropriate for this application and known to those skilled in the art. As mentioned, the raw data could also be sent to a remote processing system of any appropriate type, which can perform some or all of the processing and/or analysis described herein.

The power and control module174distributes power to all other devices in the component100, and also can be designed to control the overall operation of the component100. For example, the signals from the wheel switch108(FIG. 3) may be registered by the power and control module174and cause the remaining devices in the component100to be powered up and/or triggered for data collection.

The communications module176can transfer data from the component100, and may do so either via a wired or wireless communications method. The data transfer may include the raw data gathered by the sensing units70, results of partial or completed analysis performed onboard by the data collection unit172, and/or the like. Communications may be two-way to permit direct control, evaluation, upgrades, or testing of the component100.

Physical channels178are also shown, connected to conduits180. These conduits180may carry air (e.g., for temperature control, the prevention of contamination, and/or the like), wiring, hydraulic lines, and/or other required components to allow operation of the component100. For example, wiring may come through such a conduit180and channel178to provide power to the power and control module174, to provide a wired connection for communications module176, and/or the like.

FIG. 7shows an embodiment in an operational setting. In this embodiment, the component100is shown protected by two guard ramps200, which are designed to withstand reasonable levels of impact, and guide dragging equipment over the top of the component100rather than allowing it to strike the side of the component100. A vent conduit202is shown included, which permits the venting of air during heating or cooling operations and may include pipes to drain water which can accumulate beneath the component100.

In addition, a bungalow204is shown. The bungalow204may contain data processing equipment (e.g., one or more computing devices), power supplies, controls, and/or other systems to assist in operating the component100, to assist in maintenance and calibration, to make use (e.g., initiate an action) of the data collected (and possibly analyzed) by the component100, and/or the like. Trains206will pass over the component100and their wheel alignments evaluated. Wheel switches108can trigger and time the activation of this imaging-based evaluation. Other wheel switches108can be placed farther down the track32in both directions to allow the devices of the component100to be able to “wake up” after going into a power-saving “sleep” mode when no new cars have appeared after some time.

The communications module176(FIG. 6) in the component100may communicate to the computer system(s) in the bungalow204, e.g., by wired connections through conduits180. However, it is understood that wireless communication links208may also be used.

FIG. 8shows a conceptual flowchart of operation according to an embodiment, which can be implemented by one or more computing devices in the component100, the bungalow204, and/or the like. Initially, the system can begin in a “sleep” mode, in which many of the devices are partially or entirely powered off. In action230, a remote sensor detects the approach of a train (or other consist), and in response, in action232, the system is powered up and prepared. In response to a triggering sensor detecting a wheel in the proper position in action234, the system will obtain wheelset images in action236. In action238, these images can be prepared by filtering, averaging, or other means to ensure they are of sufficient quality for analysis as described herein. In action240, the images are evaluated. In action242, a decision can be made based on the evaluation as to whether the wheelset is in an acceptable condition or not. If the images indicate that there are one or more anomalies present, which are outside of the prescribed limits of the target conditions (e.g., hunting, angle of attack, and/or the like), in action244, an alert for these anomalies can be generated. In either event, in action246, the wheelset data can be recorded, and the process can return to action234to wait for a triggering wheel sensor.

If a triggering wheel sensor is not detected in action234, in action248, the time passed can be evaluated to determine whether the time has exceeded a “sleep” time threshold for the system. If it has not, the process returns to action234to wait for the triggering sensor. If the sleep time threshold has been exceeded, in action250, the system checks to see if an inbound car/wheel has been detected which has not yet been evaluated. If such an inbound car/wheel has been detected, the process returns to action234to continue to wait for a triggering sensor. If no remaining inbound signals have been detected, in action252, the system goes to sleep and the process returns to action230, in which a very low-level sensor evaluator monitors whether the remote sensor wheel is activated.

It is understood that this description is not exhaustive and embodiments can include any and all modifications, additions, derivations, and so on which would be evident to one skilled in the art.

The invention described herein is not limited to the specific form of the embodiments described herein, but can be instantiated in many different forms. Following are some examples of other embodiments.

One embodiment can involve installing the two imaging systems70in separate components, rather than in a single component100. In this case, each component can be located on the outside of the tracks, to image the field side of the wheel rather than the gauge side of the wheel. This embodiment can place the devices in the components generally out of range of impacts from dragging equipment on the trains206and can make installation and maintenance much easier. For example, there may be no need to impede through traffic during installation, replacement, or maintenance work. In this case, use of lasers76of superior focus and/or higher power may be required, and would expose the cameras74to additional ambient light which would not be present underneath a rail vehicle. Possible human exposure to the lasers76may also be a concern, although mounting height and the fact that the lasers76would only be operative when rail vehicles (e.g., as part of a train206) are passing (and thus human beings should not be present) may mitigate these concerns.

The foregoing description of various embodiments of this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed and inherently many more modifications and variations are possible. All such modifications and variations that may be apparent to persons skilled in the art that are exposed to the concepts described herein or in the actual work product, are intended to be included within the scope of this invention disclosure.