System and method for railroad track tie plate orientation

1. A machine for automatically orienting railroad tie plates, comprising:

a sensing region;

at least one optical sensor associated with the sensing region and connected to the machine, the at least one optical sensor including a transmitter portion arranged to transmit a sensing beam such that the sensing beam at least one of reflects and refracts at an angle from a surface of a tie plate and a receiver portion arranged to receive a visible representation of the sensing beam that at least one of reflects and refracts at the angle such that a physical feature of the tie plate is discernible, wherein the at least one optical sensor is adapted to sense the physical feature of the tie plate;

an electronic controller operably connected to the at least one optical sensor and disposed to receive therefrom a sensor signal indicative of the physical feature of the tie plate when the tie plate is in the sensing region;

wherein the electronic controller is further disposed to:

determine an orientation of the tie plate based on the sensor signal;

compare the orientation of the tie plate with a predetermined orientation; and

provide a command to at least one actuator adapted to perform at least one tie plate orientation operation to change the orientation of the tie plate based on the comparison of the orientation of the plate with the predetermined orientation.

2. The machine of claim 1 , further comprising a conveyor system adapted to transport at least one tie plate from one location of the machine to another, wherein at least a portion of the conveyor system traverses a portion of the sensing region.

3. The machine of claim 2 , wherein the conveyor system is arranged to carry the at least one tie plate while the at least one tie plate is standing on an edge thereof such that each of a bottom side and a top side of the at least one tie plate is visible to the at least one optical sensor and, further, such that the at least one tie plate arrives at the sensing region in one of four possible orientations.

4. The machine of claim 3 , wherein each plate has a generally rectangular shape having two short edges and two long edges, and wherein the conveyor system is arranged to carry the at least one tie plate while the same is standing on one of its two long edges such that the at least one optical sensor is disposed to sense a contour of the at least one tie plate that is disposed longitudinally along the at least one tie plate between the two long edges.

5. The machine of claim 1 , further including an additional optical sensor disposed adjacent the sensing region and arranged to scan a first side of the at least one tie plate as it passes through the sensing region, wherein the at least one optical sensor is arranged to scan a second side of the at least one tie plate, and wherein the additional optical sensor is arranged opposite the at least one optical sensor.

6. The machine of claim 1 , wherein the tie plate has a bottom side and a top side that includes two shoulders, wherein the signal comprises information about at least one set of points disposed along a contour of the tie plate, and wherein determining an orientation of the tie plate based on the sensor signal in the electronic controller is accomplished by one of:

inspecting each of the plurality of points and determining that the contour of the tie plate represents the bottom side when the points are collinear; and

inspecting each of the plurality of points and determining that the contour of the tie plate represents the top side when the points are not collinear.

7. The machine of claim 6 , wherein determining an orientation of the tie plate based on the sensor signal in the electronic controller further includes:

identifying the two shoulders on the top side of each tie plate;

measuring a first tie plate height at one of the two shoulders;

measuring a second tie plate height at an other of the two shoulders; and

determining a field side of the tie plate based on the larger of the first and second tie plate heights.

8. The machine of claim 1 , wherein the at least one optical sensor is arranged to capture a digital image of at least a portion of the at least one tie plate, and wherein the at least one optical sensor is arranged to provide to the electronic controller a signal indicative of the digital image.

9. The machine of claim 1 , wherein the electronic controller is further disposed to determine at least one physical dimension of the tie plate, compare the at least one physical dimension with a predetermined value, and determine the orientation of the tie plate based on the at least one physical dimension.

10. The machine of claim 1 , wherein the at least one tie plate orientation operation is an operation inverting an orientation of the tie plate, and wherein the electronic controller is further disposed to provide an additional command to an additional actuator adapted to perform a second tie plate orientation operation that reverses the orientation of the tie plate.

11. The machine of claim 1 , wherein the at least one optical sensor emits a laser beam that oscillates relative to the tie plate such that it paints a line across a portion of the tie plate to provide information that is indicative of an angle of a rail seat portion of the tie plate.

12. A method for automatically sorting and orienting tie plates in a tie plate placing machine, comprising:

sensing at least one physical feature of each tie plate by scanning a portion thereof with an optical sensor;

providing a signal indicative of a physical feature from the optical sensor to an electronic controller;

determining an orientation of each tie plate in the electronic controller based on the signal;

comparing the orientation of each tie plate with at least four predetermined orientations;

assigning an orientation designation to each tie plate based on the comparison between the orientation of each tie plate with the predetermined orientations; and

re-orienting each tie plate based on the orientation designation.

13. The method of claim 12 , wherein each tie plate has a top side and a bottom side, wherein both the top and bottom sides of each tie plate are scanned by the optical sensor and an additional optical sensor.

14. The method of claim 13 , wherein each tie plate has a generally rectangular shape having two short edges and two long edges, and wherein the method further includes carrying each tie plate standing on one of its two long edges between the optical sensor and the additional optical sensor such that each of the top and bottom sides of each tie plate is visible by one of the optical sensor and the additional optical sensor.

15. The method of claim 12 , wherein the optical sensor emits a sensing beam that paints a line along a longitudinally extending contour of each tie plate.

16. The method of claim 12 , wherein the signal provided from the optical sensor to an electronic controller includes information indicative of a position of a plurality of points disposed on a contour of each tie plate.

17. The method of claim 16 , wherein determining the orientation of each tie plate includes one of:

inspecting each of the plurality of points and determining that the contour of the tie plate represents the bottom side when the points are collinear; and

inspecting each of the plurality of points and determining that the contour of the tie plate represents the top side when the points are not collinear.

18. The method of claim 17 , wherein determining the orientation of each tie plate further includes:

identifying two shoulders on the top side of each tie plate;

measuring a first tie plate height at one of the two shoulders;

measuring a second tie plate height at an other of the two shoulders; and

determining a field side of the tie plate based on the larger of the first and second tie plate heights.