Range-finding based image processing rail way servicing apparatus and method

Information

  • Patent Grant
  • 6647891
  • Patent Number
    6,647,891
  • Date Filed
    Thursday, December 13, 2001
    23 years ago
  • Date Issued
    Tuesday, November 18, 2003
    21 years ago
Abstract
A method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature. The method includes identifying a feature of a railway, wherein the identifying involves processing an image corresponding to ranges to the feature. The apparatus includes a vision system for determining a range to a feature of the railway and means for positioning equipment relative to, for servicing, the feature, based on the range.
Description




BACKGROUND OF THE INVENTION




The repair and maintenance of railroad rights of way have always been of prime consideration to ensure safe and reliable passage of passenger and freight trains. The railroad tracks upon which these trains travel are subject to frequent and heavy traffic and loading. The cost of maintaining these tracks also is commensurate with such traffic and requires significant expenditures for materials as well as labor for installation of the materials.




In particular, railroad companies constantly engage in such maintenance activities as replacing worn cross ties or the rails which they support. Typically, the worn cross tie or rail must be removed from where it is installed, and then a new cross tie or rail must be fitted and ultimately installed in place of the worn member.




Installing a cross tie involves positioning a tie on the railway bed and mechanically vibrating the surrounding ballast or stone so that the ballast flows around the tie providing support and resistance to tie movement.




Once the cross tie is placed, the rail then must be fastened to the cross tie. Typically, a rail is connected to a cross tie with a tie plate. A tie plate has a slot which receives and maintains the base of the rail and holes for receiving spikes which fasten the tie plate to the cross tie.




Many devices have been advanced for automating the installation of cross ties and rails. Some devices index a tamping mechanism according to a distance traveled by the tamping mechanism along the rail. See, for example, U.S. Pat. Nos. 4,760,797 and 5,671,679.




Another device employs a CCD camera for two-dimensional, shape-from-shading or parallax based image recognition for locating the spike holes in a tie plate on a cross-tie of a railway, as opposed to the present three-dimensional, range-based surface profiling identification and verification. See, for example, U.S. Pat. No. 5,487,341.




Unfortunately, the everyday unpredictable environmental surface conditions of a railroad bed limit the ability of image recognition based systems to accurately locate target features of a railroad bed. What is needed is a method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature.




SUMMARY OF THE INVENTION




The invention overcomes the issues discussed above with a method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature.




The invention provides a method for servicing a railway including identifying a feature of a railway, wherein the identifying involves processing an image corresponding to ranges to the feature. The invention also provides an apparatus for servicing a railway including a vision system for determining a range to a feature of the railway and means for positioning equipment relative to, for servicing, the feature, based on the range.




The invention may be used to retrofit existing track spiking machinery to automate locating a cross tie, detecting a tie plate and spike hole thereof, and inserting and driving the track spikes into the tie plate holes into the cross tie.




The invention provides improved elements and arrangements thereof, for the purposes described, which are inexpensive, dependable and effective in accomplishing intended purposes of the invention.











Other features and advantages of the invention will become apparent upon reference to the following description and drawings.




BRIEF DESCRIPTION OF THE DRAWINGS




The invention is described below in conjunction with the following drawings, throughout which similar reference characters denote corresponding features, wherein:





FIG. 1

is schematic side view of a range-finding based image processing railway servicing apparatus according to the invention;





FIG. 2

is a schematic side view of the vision system of

FIG. 1

;





FIG. 3

is a graphical view of phases of laser light incident on and corresponding infrared energy emanating from a surface;





FIG. 4

is a schematic plan view of the vision system of

FIG. 1

irradiating a generic surface;





FIG. 5

is a graphical view of profiles traced by the laser of the vision system of

FIG. 4

;





FIG. 6

is a schematic plan view of the vision system of

FIG. 1

irradiating a railway;





FIG. 7

is a graphical view of profiles traced by the laser of the vision system of

FIG. 6

;





FIG. 8

is a display view of composite grey-scale image and feature analysis graph of an image processor corresponding to a portion of a railway;





FIG. 9

is side schematic view of the embodiment of

FIG. 1

;





FIG. 10

is diagrammatic view of functional interrelationships among components of the embodiment of

FIG. 1

;





FIG. 11

is a diagrammatic view of a flow chart of a method according to the invention;





FIG. 12

is a diagrammatic view of a flow chart of a submethod of the method of

FIG. 11

;





FIG. 13

is a display view of a range-based image of a tie edge;





FIG. 14

is a diagrammatic view of a flow chart of a submethod of the method of

FIG. 11

;





FIG. 15

is a display view of a range-based image of a spike hole;





FIG. 16

is a diagrammatic view of a flow chart of a submethod of the method of

FIG. 11

;





FIG. 17

is a diagrammatic view of a flow chart of a submethod of the method of

FIG. 11

;





FIG. 18

is a display view of a range-based image of a spike; and





FIG. 19

is a diagrammatic view of a flow chart of a submethod of the method of FIG.


11


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




The invention is a method and an apparatus for identifying a feature of a railway and deploying equipment for servicing same by image processing range data pertaining to the railway feature. Herein, “servicing” refers to installing as well as repairing activities.





FIG. 1

illustrates an embodiment of a range-finding based image processing railway servicing apparatus configured according to the invention. A carriage


100


transports railway servicing equipment


200


along a railway


300


. A motive system


400


moves carriage


100


relative to railway


300


. A vision system


500


identifies features of railway


300


. A system controller


600


coordinates functions among equipment


200


, motive system


400


and vision system


500


.




Carriage


100


includes a frame


105


which is supported by at least two sets of rotatable wheels


110


that engage rails


305


of railway


300


. Frame


105


and wheels


110


are linked so as to provide a relatively stable and constant vertical dimension


115


between vision system


500


and rails


305


of railway


300


. The vertical dimension between vision system


500


and other features of railway


300


typically varies from work site to work site. The stability and consistency of dimension


115


impacts the accuracy of vision system


500


, hence positioning of carriage


100


relative to railway


300


, as described in greater detail below.




Equipment


200


is selected from a variety of automated devices for servicing railways. For example, as discussed in greater detail below, equipment


200


may include a tie nipper


202


, for seizing and positioning railway ties


310


.




Motive system


400


includes a propulsion means (not shown), for physically moving or driving carriage


100


, and a propulsion controller (not shown), for regulating the extent that propulsion means moves carriage


100


. The propulsion means may be selected from any conventional railroad car propulsion means, such as an electric stepper motor operatively coupled to at least one of the set of wheels


110


. The propulsion means positions carriage


100


relative to a desired position along railway


300


with a precision appropriate for permitted tolerances of particular railway servicing. For example, positioning railway tie tamping equipment proximate to a tie for tamping does not require the accuracy that positioning spiking equipment relative to a spike hole of a tie plate for securing a rail to a tie, as described in greater detail below.




The propulsion controller, responsive to user or system controller


600


input, controls the propulsion means. Thus, when the user or system controller


600


instructs the propulsion controller to move carriage


100


by a certain amount, the propulsion controller transmits a motive signal to the propulsion means to move carriage


100


by the certain amount. Any of a number of known sensors may be used to apprize the propulsion controller as to the actual amount the propulsion means moves carriage


100


relative to railway


300


for providing control feedback.




Referring to

FIG. 2

, vision system


500


employs light infrared detection and ranging (LIDAR) for identifying features of a railway


300


in a manner similar to radar. Vision system


500


includes a laser emitter


505


, an infrared sensor


510


and an image processor (not shown). Laser emitter


505


emits an amplitude-modulated laser beam B across surface S. Surface S absorbs energy from laser beam B and radiates some of that energy in the form of infrared electromagnetic waves I. Sensor


510


receives some of the infrared electromagnetic waves I and transmits a signal corresponding to the phase of the received infrared energy to an image processor. As discussed in greater detail below, the image processor compares the phase of the irradiated laser beam with phase of the corresponding infrared energy and generates a virtual surface which corresponds to the actual surface irradiated by laser beam B.




The image processor identifies features from the virtual image that correspond to a target feature of the actual surface, such as rail


305


or tie


310


. Thus, the image processor ascertains a location, in three-dimensional space, of an actual target feature of a rail, tie or other element of a railway. Similarly, the image processor ascertains a location, in three-dimensional space, of a target feature of equipment maintained by carriage


100


, such as the tip of a spike extending from a spiking gun. Thus, the image processor provides positional information regarding a feature of a railway and equipment for servicing same so that the equipment may be positioned relative to the feature to perform such servicing.




Referring again to

FIG. 1

, system controller


600


receives positional information regarding railway and equipment features from the image processor. When service provided by the equipment is desired, system controller


600


controls motive system


400


to position carriage


100


along railway


300


relative to a feature for which servicing is desired, then controls the equipment controller to position and instruct the equipment for performing the desired service.





FIGS. 2-5

illustrate how vision system


500


develops a virtual surface that corresponds to an actual surface subjected to laser irradiation. Laser emitter


505


emits an amplitude-modulated laser beam B having a first waveform W


1


at a first phase φ


1


that strikes actual surface S. Surface S absorbs energy from laser beam B and radiates some of that energy in the form of infrared electromagnetic waves I having a second waveform W


2


at a second phase φ


2


. Sensor


510


receives some of the infrared electromagnetic waves I and transmits a corresponding signal conveying the phase information of the infrared electromagnetic wave to an image processor (not shown). The image processor samples the signal from sensor


510


and determines a distance or range to surface S based on a phase difference φ


D


between first phase φ


1


of the outgoing laser beam with second phase φ


2


of the received infrared energy wave. The value of phase difference φ


D


depends on, thus is indicative of, the relative distance to the irradiated surface from laser emitter


505


. An actual distance to, or range of, the irradiated surface is determined by converting the phase difference φ


D


with a calibrated conversion factor derived from comparing phase differences φ


D


associated with known actual distances.




As shown in

FIG. 4

, laser emitter


505


emits laser beam B across surface S, defining successive traces T


1


-T


n


across surface S as laser emitter traverses relative to surface S along direction D. Traces T


1


-T


n


of

FIG. 4

correspond to profiles P


1


-P


n


of surface S shown in FIG.


5


.




The image processor structures the range data obtained to correspond with actual surface S by factoring in the rate at which laser beam B traverses surface S, the sampling rate for sampling phase difference data and the proximity between traces T


1


-T


n


. Thus, image processor generates data comprising a matrix of ranges to discrete points, defining a virtual surface that corresponds with actual surface S. Increasing the sampling time and/or decreasing the distance between traces T


n


improves resolution, hence correspondence of the virtual surface with actual surface S.





FIGS. 6 and 7

illustrate a typical actual surface, railway


300


, which vision system


500


is likely to encounter during railway servicing. Laser emitter


505


emits laser beam B, defining traces T


1


-T


n


across railway


300


which correspond to profiles P


1


-P


n


, shown in FIG.


7


. An infrared sensor (not shown in

FIGS. 6 and 7

) receives some of the resultant infrared electromagnetic waves and transmits a corresponding signal conveying the phase information thereof to an image processor (not shown), which generates a corresponding, range-based virtual surface. With sufficient resolution, the virtual surface exhibits features that correspond to features of railway


300


, for example, rails


305


, ties


310


and the underlying railway bed


320


.




The image processor is provided with range-based data corresponding to features of a typical railway or other user-designated features. Such data includes, for example, characteristic range values, like the height of a rail above which no other element of a railway occurs, typical slopes between points of a range-based image, and distances between typical slope changes. The image processor also is provided with image comparison software which permits the image processor to compare the data corresponding to a typical railway with the generated virtual surface to determine whether the actual railway appears to present a specified feature. Thus, the image processor permits identification of a typical rail, tie, tie plate or other railway features.





FIG. 8

shows a composite virtual image and feature analysis graph display


700


of the image processor. An image portion


705


of display


700


shows rail


305


, extending vertically with respect to the page, tie


310


, tie plate


315


and railway bed


320


. Shading of image portion


705


relates to ranges of depicted features from the infrared sensor, as opposed to the luminescence or coloration thereof. The image processor analyzes a window


710


of image portion


705


and generates a corresponding graph


715


having a profile


720


. Profile


720


has contours that correspond to distinguishable elements in window


710


. For example, transition points


725


and


730


respectively correspond to leading and trailing edges


340


and


345


, and curve


735


corresponds to an upper surface


365


of tie


310


. The image processor, having been provided data as to the distance between transition points


725


and


730


, the slope of curve


735


or other defining relationships, identifies leading and trailing edges


340


and


345


, upper surface


365


and so forth from image analysis of graph


715


.




Once the image processor recognizes an attribute, the invention provides for verifying that the attribute identified actually is an attribute and not a misidentification. To make sure that identified attributes are not coincidental image aberrations, the image processor performs range analysis of the attribute. For example, if an area of a range-based virtual image appears to have transition points and slopes that generally correspond with image data for a spike hole, but in fact is a protruding bolt, subsequent range-finding analysis will reveal same.




The bulk of services performed on or about a railway are specific to certain features of the railway. For example, tie tamping requires locating appropriate equipment proximate to a tie and rail spiking requires locating appropriate equipment relative to a spike hole in a tie plate. To automate such services with the imaging capabilities of vision system


500


, in addition to ascertaining a particular feature of a railway, equipment


200


for servicing the particular feature must be positioned relative to the particular feature. Thus, automating such service requires ascertaining the relative location of features of an actual surface and positioning equipment


200


accordingly for servicing same.




Referring to

FIG. 9

, the invention provides for ascertaining the relative location of a feature of an actual surface and positioning equipment


200


accordingly for servicing same. Initially, the invention provides for ascertaining a range of the equipment much like the present method for ascertaining features of railway


300


. Vision system


500


performs range finding with respect to known features of equipment


200


. Thus, the relative location of equipment


200


with respect to vision system


500


is determined. Next, as shown in

FIG. 9

, vision system


500


ascertains a differential range between tie


310


and a target feature of railway


300


. Apprized of the position of and a differential range for positioning equipment


200


, the invention automatically positions equipment


200


relative to a railway feature for servicing same.




For example, equipment


200


may include, inter alia, a spiking gun


210


, such as a Fairmont Tamper Model E3 Spiker, for driving spikes (not shown) through spike holes


330


in tie plate


325


, thereby securing the foot


335


of rail


305


to tie


310


. Relative positioning of equipment


200


and vision system


300


is known from initial range finding start-up procedures. Thus, relative positioning of a spike hole to a known feature of railway


100


, tie


310


, must be determined for positioning equipment


200


relative thereto. Based on virtual image data provided to the image processor regarding the actual surface, the image processor determines a differential range between identified and verified spike hole and tie


300


. System controller


600


then controls equipment controller


205


to position equipment


200


according to the differential range relative to the feature identified by the image processor for which servicing is desired.




An advantage of the range finding based correlation of equipment


200


and railway feature positions is that no cumulative positioning errors can accrue, as occurs with systems that rely on physical measurement of service surfaces, which eventually lead to erroneous positioning of equipment relative to a service surface and faulty servicing thereof. For example, systems that ascertain carriage position relative to a railway by physically measuring the length of rail passing thereunder, directly or via a wheel traversing the rail, even if calibrated carefully, accrue slight positional errors between successive actual and measured positions, which eventually lead to positioning equipment, such as a spiking gun, considerably astray from a spike hole.




In other embodiments of the invention, equipment


200


may include: a tamper (not shown) for installing a tie into a prepared section of railway bed


320


; rail anchor adjusters (not shown) for seizing and positioning rail anchors; rail anchor spreaders (not shown) for providing adequate space for removing an undesired tie and replacing same with a new tie; Pandrol screw machines and clip applicators (not shown), for connecting rails, tie plates and ties with screws and clips; tie drilling machines (not shown), for drilling holes in ties; liquid tie plugging equipment (not shown), for plugging holes in ties; and other equipment available for servicing a railway that is specific to features of the railway.





FIG. 10

diagrammatically outlines exemplary functional interrelationships among the foregoing components as background for subsequent discussion of a method configured according to the invention. Generally, system controller


600


receives input from vision system


500


and provides input to motive means


400


. More specifically, within vision system


500


, infrared sensor


510


receives input from laser emitter


505


, regarding output laser emission phase, and outputs same, along with data regarding the phase of sensed infrared waves corresponding to the laser emission, to an image processor


515


. Image processor


515


outputs to system controller


600


data derived from the data received from infrared sensor


510


. Within motive means


400


, propulsion controller


405


receives input from system controller


600


pertaining to a desired distance to move carriage relative to railway


300


. Propulsion controller


405


determines the proper velocity and acceleration based upon the distance, grade, pre-programed parameters and machine responsiveness, and provides corresponding input for controlling the activity of propulsion means


410


to move carriage


100


the desired amount relative to railway


300


.





FIG. 11

diagrammatically outlines basic features of a range-finding based image processing railway servicing method configured according to the invention. At step S


100


, the method provides for identifying a worksite of a railway. At step S


200


, the method provides for positioning carriage


100


carrying equipment


200


relative to the work site feature. At step S


300


, the method provides for identifying an attribute of the work site feature which equipment


200


is to service. At step S


400


, the method provides for positioning equipment


200


relative to the work site attribute. At step S


500


, the method provides for servicing the worksite with the equipment.




More specifically, step S


100


includes step S


105


for identifying a worksite feature. Example worksite features are a rail, a tie, a tie plate, an anchor or other common features found on a railway. A user may input image data associated with a desired target feature and attributes thereof or select same from a catalog of images provided to the image processor.




“Identifying” means establishing correspondence between data pertaining to a predicted image of a desired feature of the railway and an actual image of the feature. For example, if desired servicing includes tamping a tie into a prepared section of a railway bed, the method would provide for identifying the tie. To this end, in accordance with the method, a user would provide an image processor of a vision system, as described above, with data corresponding to an anticipated image of a tie. The vision system would scan the railway and provide corresponding range information to the image processor. The image processor would compare the anticipated tie image with features of the generated virtual surface. When the vision system scans an actual tie, the image processor would generate a virtual surface corresponding to the actual tie. Once the image processor determines the existence of correspondence between the virtual surface corresponding to the actual tie and the anticipated tie image, the image processor has identified the worksite feature, the tie. Herein, “locating” is used interchangeably with “identifying.”




At step S


110


, the method provides for verifying the work site feature. Verification assures that an identified element of a virtual surface has the characteristics of a desired element, rather than an element that only looks like the element. For example, a groove in tie


310


could be represented on virtual surface as a dark line, which would have potential for being identified as a leading or trailing edge. To make sure that the equipment does not service the wrong part of a tie, the method verifies whether the dark line is an edge or a groove along tie


310


.




Referring to

FIG. 12

, the method of step S


110


provides a step S


110


.


1


for positioning an analysis window


740


about a feature attribute identified by the image processor, for example, trailing edge


345


, as shown in FIG.


8


and in an enlarged scale in FIG.


15


. At step S


110


.


2


, the method provides for extracting the range values for each pixel PX of five vertical columns V


1


-V


5


of pixels PX in window


740


. As shown, each column V


1


-V


5


contains five rows R


1


-R


5


of pixels PX. At step S


110


.


3


, the method provides for averaging the range values across each row R


1


-R


5


. Averaging each row avoids the potential for a local surface deformity, such as a pock mark, from distorting subsequent calculations. At step S


10


.


4


, the method provides for determining the slopes between the average range values to find an inflection point which would be indicative of an edge. At step


110


.


5


, the method provides for comparing the determined slopes with an appropriate slope. At step


110


.


6


, the method provides for comparing the measured distance from leading edge to the appropriate slope with a minimum distance to ensure that point where appropriate slope occurs is where appropriate for an actual trailing edge. For example, the appropriate slope must not exist within a minimum distance of ½ tie width. If the appropriate slope is determined to exist within ½ tie width, then a non-standard condition exists which may not be serviceable. At step


110


.


7


, once the minimum distance is verified, the method provides for comparing the measured height of the tie with a minimum height. At step


110


.


8


, following height verification, the method provides for declaring the feature “verified.”




Returning to

FIG. 11

, once the work site feature is identified and verified, at step S


115


, the method provides for ascertaining the differential range to the work site feature for positioning carriage


100


relative to the work site feature. To this end, the image processor determines a distance between a current location, identified and verified previous to step S


100


, and an intended location, respectively identified and verified in steps S


105


and S


110


.




At step S


200


, the method provides for positioning carriage


100


relative to the work site feature according to the differential range thereto. System controller


600


receives the differential range information from the image processor and transmits a corresponding propulsion signal to propulsion controller


405


. Propulsion controller


405


responds to the propulsion signal and transmits instructions regarding the proper velocity and acceleration to propulsion means


410


to move carriage


100


relative to railway


300


an amount corresponding to the differential range, thereby positioning carriage


100


proximate to the identified and verified work site feature.




Step S


200


not only positions carriage


100


, but also generally positions equipment


200


relative to the identified and verified work site feature. Subsequent step S


400


fine tunes the positioning of equipment


200


by manipulating same relative to carriage


100


with equipment positioning means


210


, as described below. Generally positioning equipment


200


relative to the work site feature by moving carriage


100


factors in the location of equipment


200


with respect to carriage


100


.




Referring to

FIG. 17

, the method provides a sub-method for ascertaining the location of equipment


200


, more specifically a fiducial point thereof, such as a spike tip, with respect to carriage


100


. The sub-method may be executed once prior to performing any of a number of services with equipment


200


, as part of every service performance by equipment


200


, or at times and frequencies deemed appropriate. Step S


000


provides for positioning a search window about where a fiducial point is expected, such as about spike


220


, as shown in FIG.


20


. Step S


005


provides for obtaining a range threshold to the fiducial, spike


220


. Step S


010


provides for locating the lower extent of foreground spike


220


. Step S


015


provides for evaluating the configuration, or taper, cant and width, of spike


220


. Step S


020


provides for sampling the range to spike


220


and determining a range to the fiducial point. The image processor stores this range for subsequent carriage positioning calculations so that the fiducial point of equipment


200


may be positioned generally proximate to a work site feature.




Returning to

FIG. 11

, at step S


300


, the method provides for identifying an attribute, such as a tie plate spike hole, of the work site feature. As with step S


100


, user may input image data associated with a desired target attribute select same from a catalog of images provided to the image processor.




At step S


305


, the method provides for verifying the feature attribute. Verification assures that an identified attribute of a virtual surface has the characteristics of a desired attribute, rather than an attribute that only looks like an attribute. For example, a gouge in tie plate


325


could be represented on virtual surface as a dark square, which would have potential for being identified as a spike hole. To make sure that the equipment does not introduce a spike into a gouge, the method verifies whether the dark square is a hole.





FIG. 14

diagrams a sub-method of step S


305


for verifying identified spike holes


330


in tie plate


325


. Step S


305


.


1


provides for positioning an analysis window


743


around a target, spike holes


330


, and a reference feature, rail foot


335


, as shown in FIG.


8


. Ascertaining ranges for the reference aids in making sure that tie plate and spike holes are situated appropriately vertically relative to rail


305


. Step S


305


.


2


provides for ascertaining and normalizing the range to reference rail foot


335


. Step S


305


.


3


provides for filtering noise associated with the reference ranging. Step S


305


.


4


provides for determining a range threshold of the reference. Step S


305


.


5


provides for extracting a local edge of the reference, rail foot


335


, with the column averaging technique described above.




Referring also to

FIG. 15

, which shows spike hole


330


in an enlarged scale, the method continues at step S


305


.


6


, which provides for extracting a “stripe” of pixels across the attribute, spike hole


330


, similar to that described above for step S


110


.


2


. Step S


305


.


7


provides for analyzing the stripe and locating a target of the attribute, a leading edge of spike hole


330


. Step S


305


.


8


provides for evaluating the configuration of ranges in the pattern to verify the target, leading edge of hole


330


.




Returning to

FIG. 11

, at step S


310


, the method provides for ascertaining a differential range between the attribute, spike hole


330


, and equipment


200


. Referring to

FIG. 16

, step S


310


includes step S


310


.


1


, which provides for locating the outside edge, or edge farthest from the rail base, of spike hole


330


, as shown in FIG.


15


. Step S


310


.


2


provides for cross-tracking, or identifying the theoretical, center


333


of spike hole


330


. Step S


310


.


3


provides for locating the leading edge


334


of spike hole


330


. Step S


310


.


4


provides for locating the leading edges (not shown) of the other spike holes (not shown). Step S


310


.


5


provides for verifying the configuration of ranges in pattern again. Step S


310


.


6


provides for sampling the ranges at the three leading edge positions and at back of the spike holes. Step S


310


.


7


provides for translating and rotating spike hole points.




Step S


310


.


7


employs ordinary trigonometric formulae to establish a horizontal relationship between the spike holes and the equipment selected to service same, a spiking gun. Referring again to

FIG. 2

, based on the range data for points


340


and


345


, the distance


350


between infrared sensor


510


and rail


305


and the angle


355


relative to rail


305


at which laser beam B is directed across railway


300


, the image processor determines a distance


360


along rail


305


from sensor


510


to, for example, a center of spike hole


330


.




Returning again to

FIG. 11

, at step S


400


, the method provides for positioning equipment


200


relative to the feature attribute according to the differential range thereto. System controller


600


receives the differential range information from the image processor and transmits a corresponding positioning signal to equipment controller


205


. Equipment controller


205


responds to the positioning signal and transmits instructions regarding the proper velocity and acceleration to equipment positioning means


210


to move equipment


200


relative to carriage


100


and/or railway


300


an amount corresponding to the differential range, thereby positioning equipment


200


proximate to the identified and verified work site feature attribute.




At step S


500


, once the equipment is positioned, the method provides for servicing the work site with the equipment. As shown in

FIG. 19

, step S


500


includes step S


500


.


1


, which provides for inserting spike


220


in spike hole


330


. Step S


500


.


2


provides for driving spike


220


into spike hole


330


.




Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. The present invention is not limited by the specific disclosure herein, but only by the appended claims.



Claims
  • 1. A method of servicing a railway, said method comprising:identifying a feature of a railway based upon a range measurement from a vision system to the feature being identified, said vision system employing light infrared detection and ranging; irradiating the feature by at least one laser beam emitted by at least one laser emitter; sensing energy radiated from the feature due to said irradiation by said laser beam by at least one infrared sensor; transmitting at least one signal corresponding to a property of said sensed energy; comparing a property of said emitted laser beam to said transmitted signal for three-dimensional identification of the feature; processing a three-dimensional image of the feature based upon the range measurement; and servicing the railway.
  • 2. Method of claim 1, wherein said identifying comprises establishing correspondence between the image and data pertaining to a predicted image of the feature.
  • 3. Method of claim 1, further comprising verifying the feature.
  • 4. Method of claim 3, wherein said verifying comprises:locating an inflection point on the image indicative of an attribute of the feature; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 5. Method of claim 4, further comprising:measuring a distance from the inflection point to another attribute of the feature; and determining whether the distance falls within a predetermined range.
  • 6. Method of claim 4, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 7. Method of claim 3, wherein said verifying comprises:extracting range values for each pixel of a plurality of columns of pixels of the image; determining average range values across each row across the columns; determining slopes between the average range values; locating an inflection point indicative of an attribute of the feature from the slopes; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 8. Method of claim 7, further comprising:measuring a distance from the inflection point to another attribute of the feature; and determining whether the distance falls within a predetermined range.
  • 9. Method of claim 7, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 10. Method of claim 1, further comprising positioning equipment relative to, for servicing, the feature based on said identifying.
  • 11. Method of claim 10, wherein said positioning comprises ascertaining a range to a fiducial point of the equipment.
  • 12. Method of claim 10, wherein said positioning comprises determining a differential range between a current position and a position associated with the feature.
  • 13. Method of claim 10, wherein:the equipment is mounted on a carriage that is moveable relative to the railway; and said positioning comprises instructing equipment positioning means to move the equipment, instructing carriage positioning means to move the carriage or combinations thereof.
  • 14. Method of claim 1, further comprising positioning a carriage carrying equipment relative to, for servicing, the feature based on said identifying.
  • 15. Method of claim 14, further comprising positioning the equipment relative to the carriage based on said identifying.
  • 16. A method of servicing a railway, said method comprising:locating a feature of a railway based upon a range measurement from a vision system the feature being located, said vision system employing light infrared detection and ranging; irradiating the feature by at least one laser beam emitted by at least one laser emitter; sensing energy radiated from the feature due to said irradiation by said laser beam by at least one infrared sensor; transmitting at least one signal corresponding to a property of said sensed energy; comparing a property of said emitted laser beam to said transmitted signal for three-dimensional identification of the feature; positioning a carriage carrying equipment relative to, for servicing, the feature based on said locating; identifying a three-dimensional attribute of the feature; and positioning the equipment with respect to the carriage relative to the attribute based on one or both of said locating and said identifying.
  • 17. Method of claim 16, further comprising servicing the attribute with the equipment.
  • 18. Method of claim 16, wherein one or both of said locating and said identifying comprises establishing correspondence between an actual image of the feature or attribute and data pertaining to a predicted image thereof.
  • 19. Method of claim 18, wherein the actual image is based on range data.
  • 20. Method of claim 16, further comprising verifying the feature.
  • 21. Method of claim 20, wherein said verifying comprises:locating an inflection point on an image of the feature which is indicative of an attribute of the feature; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 22. Method of claim 21, wherein the image is based on range data.
  • 23. Method of claim 21, further comprising:measuring a distance from the inflection point to another attribute of the feature; and determining whether the distance falls within a predetermined range.
  • 24. Method of claim 21, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 25. Method of claim 20, wherein said verifying comprises:extracting range values for each pixel of a plurality of columns of pixels of an image of the feature; determining average range values across each row across the columns; determining slopes between the average range values; locating an inflection point indicative of an attribute of the feature; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 26. Method of claim 25, further comprising:measuring a distance from the inflection point to another attribute of the feature; and determining whether the distance falls within a predetermined range.
  • 27. Method of claim 25, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 28. Method of claim 16, further comprising verifying the attribute.
  • 29. Method of claim 28, wherein said verifying comprises:locating an inflection point on an image of the attribute which is indicative of an predetermined point of the attribute; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 30. Method of claim 29, wherein the image is based on range data.
  • 31. Method of claim 29, further comprising:measuring a distance from the inflection point to another predetermined point of the attribute; and determining whether the distance falls within a predetermined range.
  • 32. Method of claim 29, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 33. Method of claim 28, wherein said verifying comprises:extracting range values for each pixel of a plurality of columns of pixels of an image of the attribute; determining average range values across each row across the columns; determining slopes between the average range values; locating an inflection point indicative of a predetermined point of the attribute; ascertaining a slope at the inflection point; and determining whether the slope falls within a predetermined range.
  • 34. Method of claim 33, further comprising:measuring a distance from the inflection point to another predetermined point of the attribute; and determining whether the distance falls within a predetermined range.
  • 35. Method of claim 33, further comprising:measuring a height of the inflection point; and determining whether the height falls within a predetermined range.
  • 36. Method of claim 16, further comprising positioning equipment relative to, for servicing, the feature based on one or both of said locating and said identifying.
  • 37. Method of claim 36, wherein said positioning comprises ascertaining a range to a fiducial point of the equipment.
  • 38. Method of claim 36, wherein said positioning comprises determining a differential range between a current position and a position associated with the feature.
  • 39. Method of claim 36, wherein:the equipment is mounted on a carriage that is moveable relative to the feature; and said positioning comprising instructing equipment positioning means to move the equipment, instructing carriage positioning means to move the carriage or combinations thereof.
  • 40. Method of claim 16, further comprising positioning a carriage carrying equipment relative to, for servicing, the feature based on one or both of said locating and said identifying.
  • 41. Method of claim 40, further comprising positioning the equipment relative to the carriage based on one or both of said locating and said identifying.
  • 42. Apparatus for servicing a railway, said apparatus comprising:a vision system for determining a range from said vision system to a feature of the railway, said vision system being capable of three-dimensional identification of the feature and employing light infrared detection and ranging; at least one laser emitter for emitting at least one laser beam for irradiating the feature; at least one infrared sensor for sensing energy radiated from the feature due to said irradiation by said laser beam; at least one transmitter for transmitting at least one signal corresponding to a property of said sensed energy; a system for comparing a property of said emitted laser beam to said transmitted signal for three-dimensional identification of the feature; means for positioning equipment relative to, for servicing, the feature, based on the range determination by said vision system; and means for identifying a three-dimensional attribute of the feature.
  • 43. Apparatus of claim 42, whereinsaid system including an image processor for comparing the phase expressed by said transmitted signal with a phase of said laser beam and generating a range signal corresponding to the range, wherein said means for identifying being a sensor for sensing energy originating from the feature and generating a signal expressing the phase of the energy.
  • 44. Apparatus of claim 42, further comprising a carriage for carrying said vision system and said means for positioning equipment.
  • 45. Apparatus of claim 44, wherein said means for positioning equipment comprises carriage positioning means for moving the carriage relative to the railway, equipment positioning means for moving the equipment relative to said carriage, or combinations thereof.
  • 46. Apparatus of claim 42, further comprising equipment for servicing the railway operably connected to said means for positioning.
  • 47. Apparatus of claim 46, wherein the equipment comprises a tie tamper, a spiking gun, a rail anchor adjuster, a rail anchor spreader, a Pandrol screw machine, a Pandrol clip applicator, a tie drilling machine, liquid tie plugging equipment or combinations thereof.
  • 48. Apparatus of claim 42, wherein said vision system comprises:means for identifying all four sides of a spike hole; and means for directing motion of a spike gun both along a track and across a track.
CROSS REFERENCE TO RELATED APPLICATION

This application incorporates and claims the benefit of U.S. Provisional Application Serial No. 60/258,080, filed Dec. 22, 2000, by K. Dexter Roberts, entitled Spiker Eye (Laser Actuated Tie Finder).

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Provisional Applications (1)
Number Date Country
60/258080 Dec 2000 US