Automatic carriage alignment

• US 20010032513A1
• Filed: 01/05/2001
• Published: 10/25/2001
• Est. Priority Date: 01/05/2000
• Status: Active Grant

• Current Assignee: Sperry Rail Inc. (Rockwood Service Corporation)
• Original Assignee: Sperry Rail Inc. (Rockwood Service Corporation)
• Inventors: Bakach, Joseph S. Jr., Havira, Robert Mark
• Granted Patent: US 6,516,668 B2
• Time in Patent Office: Days
• US Class Current: 73/636
• CPC Class Codes: B61K 9/10 for detecting cracks in rails or welds thereof
• CPC Class Codes: G01B 17/00 Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/2623 Rails; Railroads
• CPC Class Codes: G01N 29/225 Supports, positioning or alignment in moving situation
• CPC Class Codes: G01N 29/2493 Wheel shaped probes

Abstract

An ultrasonic aligning device for laterally aligning a rail testing device with respect to a rail has an ultrasonic transducer formed of an array of closely spaced ultrasonic elements, with center to center distances between elements being selected to determine incremental lateral positions of the array relative to the rail. The ultrasonic elements are selectively actuated to cause the generation of ultrasonic beams towards the base portion of the rail. Reflections from the base portion are detected to produce reflection signals representative of the incidence of the ultrasonic beam onto said base portion. The reflection signals are processed by a reflection analyzer for a determination of the lateral offset of the ultrasonic array relative to the rail. A position signal indicative thereof is produced and used to laterally displace the array to achieve a desired lateral alignment of the rail testing device with the rail.

Claims

1. An ultrasonic aligning device for laterally aligning a rail testing device with respect to a rail being tested with a carriage structure that moves along the rail and supports the ultrasonic aligning device and the rail testing device so that these can be laterally adjusted by an actuator, comprising:

an array of closely spaced ultrasonic transducer elements, with center to center distances between elements being selected to determine incremental lateral positions of the array relative to the rail;

a wheel enclosing the array and being positioned on top of the rail with said array being aligned laterally with respect to said rail;

means for scanning the ultrasonic elements and causing the generation of ultrasonic beams towards the rail from respective ultrasonic elements and for detecting reflections caused by the beams from an interface on the bottom of the rail;

a reflection signal analyzer responsive to detected reflections from respective elements to determine the lateral position of the ultrasonic array relative to the rail and produce a position signal indicative thereof; and

an actuator responsive to the position signal to laterally displace the rail testing device in a direction selected to align the rail testing device with the rail.

2. The ultrasonic aligning device defined in

claim 1

wherein the reflection analyzer further includes means for determining which ultrasonic elements caused reflections from said interface and which elements failed to cause a said reflection during a scanning of the array of elements;

and means for deriving from said determining means said position signal indicative of the amount of misalignment of said array with respect to said rail.

3. The ultrasonic aligning device defined in

claim 2

wherein the reflection analyzer further includes means for scanning said ultrasonic elements in successive groups of a predetermined number of elements selected from the array.

4. The ultrasonic aligning device defined in

claim 3

wherein said reflection analyzer further includes means for validating the reflection signals from the groups.

5. The ultrasonic aligning device defined in

claim 3

wherein said scanning means scans consecutively located elements in said groups.

6. The ultrasonic aligning device defined in

claim 1

wherein the array has a center, and wherein the reflection analyzer further includes means for generating said position signal from a detection during a said scan of a transition of reflections and an absence of reflections.

7. The ultrasonic aligning device defined in

claim 1

wherein said array of elements is oriented within said wheel to direct beams of ultrasonic energy at a region of the base located below a web of the rail.

8. The ultrasonic aligning device defined in

claim 1

wherein the reflection analyzer includes gating means for detecting reflections from said base region.

9. The ultrasonic aligning device defined in

claim 8

, wherein the gating means is of sufficient duration to accommodate a plurality of rail sizes.

10. The ultrasonic aligning device defined in

claim 9

11. The ultrasonic aligning device defined in

claim 1

wherein the reflection analyzer includes software for analyzing detected reflections

12. The ultrasonic aligning device defined in

claim 11

wherein the software includes means for deriving valid reflections in accordance with criteria including definitive patterns, consisting of consecutive hits, followed by consecutive non-hits, consecutive non-hits, followed by consecutive hits, consecutive non-hits, followed by consecutive hits followed by consecutive non-hits.

13. An ultrasonic aligning device for laterally aligning a rail testing device with respect to a rail being tested with a carriage structure that moves along the rail and laterally moveably supports the ultrasonic aligning device and the rail testing device, comprising:

an ultrasonic transducer formed of an array of closely spaced ultrasonic elements, with center to center distances between elements being selected to determine incremental lateral positions of the array relative to the rail;

the array being positioned opposite the top of the rail and having a predetermined lateral alignment relative to the rail;

an ultrasonic element activating and receiver circuit to cause the generation of ultrasonic beams towards the rail and formed by selectively actuated ultrasonic elements extending across the array and produce echo signals representative of the incidence of the ultrasonic beam onto a base portion of the rail;

an echo analyzer responsive to echo signals representative of acoustic reflections of the base portion to determine the lateral position of the ultrasonic array relative to the rail and including a computer;

a software executing on a computer for validating at least one group of predetermined base patterns to enable the echo analyzer to produce a position signal indicative of the lateral position of the ultrasonic array; and

an actuator responsive to the position signal to laterally displace the carriage structure in the predetermined lateral alignment in response to the position signal.

14. The ultrasonic alignment device defined in

claim 13

wherein the carriage structure includes first and second probe wheels, which are ultrasonically aligned with respectively parallel rails, the actuator being a hydraulic actuator.

15. The ultrasonic alignment device defined in

claim 14

wherein each of the first and second probe wheels is provided with an array of acoustic elements.

16. The ultrasonic aligning device defined in

claim 14

and further including validation means for confirming a valid scanning of elements with criteria consisting of consecutive hits, followed by consecutive non-hits, consecutive non-hits, followed by consecutive hits, and consecutive non-hits, followed by consecutive hits, followed by consecutive non-hits.

17. A method for laterally aligning a rail testing device with respect to a rail being tested with a carriage structure that moves along the rail and laterally moveably supports an ultrasonic aligning device and a rail testing device, comprising the steps of:

moving an array of ultrasonic elements along the top of the rail with the array directed to inject ultrasonic beams into the rail through a web of the rail and onto its base and with the array oriented laterally with respect to the longitudinal dimension of the rail;

while the array is moving, scanning the array by activating ultrasonic pulses from individual elements in the array and detecting acoustic reflections arising from an incidence of respective element beams onto an interface of the base of the rail;

storing signals indicative of reflections and an absence of reflections with said interface as a function of said elements;

deriving from said stored signals a position signal indicative of the alignment of the array relative to said rail; and

laterally moving said rail testing device in a direction so as to reduce the position signal and align the rail testing device with said rail.

19. The method defined in

claim 19

wherein said deriving step includes the steps of

determining whether stored reflections from the scanning of said array include a first pattern consisting of consecutive hits followed by consecutive non-hits,

determining whether stored reflections include a second pattern consisting of consecutive non-hits, followed by consecutive hits,

determining whether stored reflections include a third pattern consisting of consecutive non-hits, followed by consecutive hits, followed by consecutive non-hits,

validating said scanning step when any one of said patterns has been determined to be present in said stored reflections.

18. The method defined in

claim 19

wherein said scanning step comprises the steps of:

activating elements in the array in predetermined successively located groups and

detecting reflections attributable to elements activated in said groups.

20. The method defined in

claim 19

wherein said deriving step further includes the steps of:

determining the element in the array for which a stored reflection or absence thereof is indicative of a transition identifying a side of a web in the rail and generating said position signal therefrom.

21. The method defined in

claim 19

wherein said deriving step further includes the steps of:

determining the elements in the array for which stored reflections or absences thereof are indicative of transitions identifying opposite sides of a web in the rail and generating said position signal therefrom.