Sensor synchronization apparatus and method

• US 9,849,895 B2
• Filed: 05/29/2015
• Issued: 12/26/2017
• Est. Priority Date: 01/19/2015
• Status: Active Grant

• Current Assignee: Tetra Tech Incorporated
• Original Assignee: Tetra Tech Incorporated
• Inventors: Mesher, Darel
• Primary Examiner(s): Ahmed, Jamil
• Application Number:
  US14/724,890
• Publication Number:
  US 20160207551A1
• Time in Patent Office: 942 Days
• CPC Class Codes: B61L 23/04 for monitoring the mechanical state of the route
• CPC Class Codes: B61L 23/044 Broken rails
• CPC Class Codes: B61L 23/045 Rail wear
• CPC Class Codes: B61L 23/047 Track or rail movements
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01B 21/04 by measuring coordinates of points

Abstract

A system and method for inspecting a railway track bed using a plurality of sensors that are synchronized for rapid interrogation of a railway track bed while the sensors are in motion at a high rate of speed.

Claims

1. A system for inspecting railway track infrastructure at high speed and high resolution, the system comprising:

a power source;

a light emitting apparatus powered by the power source for emitting light energy toward a railway track bed;

a data storage apparatus;

a first sensor directed to a first viewing area for sensing reflected light that was emitted from the light emitting apparatus and acquiring three dimensional elevation and intensity data of the railway track bed to be stored in the data storage apparatus;

a second sensor substantially collinear with and adjacent to the first sensor and directed to the first viewing area for sensing reflected light that was emitted from the light emitting apparatus and acquiring three dimensional elevation and intensity data of the railway track bed to be stored in the data storage apparatus;

a high resolution distance measuring encoder for providing longitudinal sample pulse distance data; and

at least one processor in communication with the data storage apparatus, the first sensor, the second sensor, and the distance measuring encoder wherein the at least one processor is configured for sequencing the timing of operation for the first sensor and the second sensor in a cascading, repeating manner such that the first sensor is triggered for operation while the second sensor is on standby and wherein the second sensor is triggered for operation while the first sensor is on standby, and wherein multiplexed data gathered by the first sensor and the second sensor are combined and demultiplexed_to generate a higher resolution resultant three dimensional elevation and intensity data of the railway track bed than if only a single sensor were used.

2. The system of claim 1 wherein the longitudinal resolution of the system comprises a resolution ranging from about 0.002 meters between samples to about 0.003 meters between samples when the system travels longitudinally at a speed ranging from about 70 kilometers per hour to about 110 kilometers per hour wherein the first sensor and the second sensor are each configured to take a maximum of from about 4500 samples per second to about 5500 samples per second.

3. A system for inspecting railway track infrastructure at high speed and high resolution, the system comprising:

a power source;

a light emitting apparatus powered by the power source for emitting light energy toward a railway track bed;

a data storage apparatus;

a first sensor directed to a first viewing area for sensing reflected light that was emitted from the light emitting apparatus and acquiring three dimensional image data of the railway track bed to be stored in the data storage apparatus;

a second sensor substantially collinear with and adjacent to the first sensor and directed to the first viewing area for sensing reflected light that was emitted from the light emitting apparatus and acquiring three dimensional elevation and intensity data of the railway track bed to be stored in the data storage apparatus;

an N sensor substantially collinear with and adjacent to the second sensor and directed to the first viewing area, wherein N is a set of one or more ordinal numbers each of which equals a different integer of 3 or greater, for sensing reflected light that was emitted from the light emitting apparatus and acquiring three dimensional image data of the railway track bed to be stored in the data storage apparatus;

a high resolution distance measuring encoder for providing longitudinal sample pulse distance data; and

at least one processor in communication with the data storage apparatus, the first sensor, the second sensor, the N sensor, and the distance measuring encoder wherein the processor is configured for sequencing the timing of operation for the first sensor, the second sensor, and the N sensor in a cascading, repeating manner such that the first sensor is triggered for operation while the second sensor and the N sensor are on standby, wherein the second sensor is triggered for operation while the first sensor and the N sensor are on standby, and wherein the N sensor is triggered for operation while the first sensor and the second sensor are on standby, and wherein multiplexed data gathered by the first sensor, the second sensor and the N sensor are combined and demultiplexed to generate a higher resolution resultant three dimensional elevation and intensity data of the railway track bed than if only two sensors were used.

4. The system of claim 3 wherein N={3, 4}.

5. The system of claim 3 wherein N={3, 4, 5}.

6. A method of inspecting railway track infrastructure at high speed and high resolution, the method comprising the steps of:

a. emitting light from a light source toward a railway track bed;

b. receiving longitudinal sample pulse distance data from a high resolution distance measuring encoder;

c. sequencing the timing for activation of a first sensor and a second sensor directed to the same viewing area in a repeating pattern based on the received longitudinal sample pulse distance data so that the first sensor is activated during time periods when the second sensor is on standby and the first sensor is on standby during time periods when the second sensor is activated, wherein the first sensor is collinear with and adjacent to the second sensor;

d. detecting light reflected from the railway track bed using the first sensor while the first sensor is activated; and

e. detecting light reflected from the railway track bed using the second sensor while the second sensor is activated.

7. The method of claim 6 further comprising the steps of:

f. compiling a data set of first elevation data based on the light detected by the first sensor; and

g. compiling a data set of second elevation data based on the light detected by the second sensor.

8. The method of claim 7 further comprising the steps of:

h. storing the first elevation data on a data storage apparatus; and

i. storing the second elevation data on a data storage apparatus.

9. The method of claim 7 further comprising the step of combining and demultiplexing the first elevation data and the second elevation data to compile a total elevation data set.

10. The method of claim 9 wherein the total elevation data set has a longitudinal resolution ranging from about 0.002 m between samples to about 0.004 m between samples while the first sensor and the second sensor are traveling at a speed ranging from about 70 km per hour to about 110 km per hour.

11. The method of claim 9 further comprising the step of analyzing the total elevation data set to inventory components of the railway track infrastructure and to assess the condition of the railway track infrastructure.

12. The method of claim 6 wherein the sequencing step further comprises the steps of triggering the activation of the first sensor based on an encoder first phase signal and triggering the activation of the second sensor based on an encoder second phase signal.

13. The method of claim 6 further comprising the steps of:

f. sequencing the timing for activation of a third sensor so that the third sensor is activated during a time period when the first sensor and the second sensor are on standby; and

g. detecting light reflected from the railway track bed using the third sensor while the third sensor is activated.

14. The method of claim 7 further comprising the steps of compiling a multiplexed data set of third elevation data based on the light detected by the third sensor and combining and demultiplexing the first elevation data, the second elevation data and the third elevation data to compile a total elevation data set.

15. The method of claim 14 wherein the total elevation data set has a longitudinal resolution ranging from about 0.001 m between samples to about 0.003 m between samples while the first sensor, the second sensor and the third sensor are traveling at a speed ranging from about 70 km per hour to about 110 km per hour.