Railroad car lateral instability and tracking error detector

• US 20060261218A1
• Filed: 06/29/2005
• Published: 11/23/2006
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: Progressive Rail Technologies Incorporated
• Original Assignee: Progressive Rail Technologies Incorporated
• Inventors: Martin, Robert W., Handal, Stephen N., Mace, Stephen E.
• Granted Patent: US 7,708,232 B2
• Time in Patent Office: Days
• US Class Current: 246/169.R
• CPC Class Codes: B61F 5/386 fluid actuated
• CPC Class Codes: B61F 9/00 Rail vehicles characterised by means for preventing derailing, e.g. by use of guide wheels
• CPC Class Codes: B61K 9/12 Measuring or surveying wheel-rims measuring techniques G01

Abstract

The current invention is intended to be installed in revenue service railroad tracks to detect railroad cars exhibiting wheel set lateral instability. The invention utilizes an array of inductive proximity sensors mounted at regular intervals in a section of railroad track. Each proximity sensor is oriented to sense the lateral position of railroad car wheel sets. The invention employs a computer algorithm to extrapolate the trajectory from the set of proximity sensor signals for each wheel set. A second algorithm evaluates the shape of the trajectory to detect oscillating lateral motion of the wheel set. A third algorithm assesses the severity of any wheel set lateral oscillations that are detected. An additional function of the invention is to detect railroad car trucks that exhibit “tracking errors”.

Claims

1. A railroad car lateral instability/tracking detection system for detecting wheel and/or truck tracking errors, the system comprising:

a plurality of proximity sensors mounted adjacent to a left rail of a railroad track;

a plurality of proximity sensors mounted adjacent to a right rail of the railroad track;

wherein most left proximity sensors oppose a respective right proximity sensor to enable a concurrent sensing of a left and a right wheel of a passing wheel set;

an applied voltage to the proximity sensors;

a data collection/control computer (DCCC);

wherein the passing wheel set changes an electrical field of each of the left and the right proximity sensors, thereby creating an output signal to the DCCC; and

wherein a program in the DCCC computes a tracking error of the wheel set.

2. The system of claim 1 further comprising a railroad car identification system having a tag reader and a wheel detector, wherein the DCCC program correlates a wheel set to a railroad car identity.

3. The system of claim 1, wherein the proximity sensors have a detection range of about 0 millimeter to less than about 100 millimeters.

4. The system of claim 1, wherein the proximity sensors each further comprise a mounting bracket and a clamp means functioning to secure the mounting bracket to the track at a chosen distance from a top segment of the rail.

5. The system of claim 1, wherein the output signal is either a zero volt output for a flange tip point (FTP) outside a detection envelope or a set voltage output for a FTP inside the detection envelope.

6. The system of claim 5, wherein the DCCC program computes a shift left or right of a wheel set by sensing a zero volt/set voltage output pattern from opposing sensors.

7. The system of claim 6, wherein a lateral oscillation amplitude of a wheel set is computed by the DCCC program as a function of sequential zero volt signals.

8. The system of claim 6, wherein the DCCC program uses a maximum lateral acceleration (amax) as an indicator of a relative severity of lateral instability.

9. A railroad car wheel tracking detection system comprising:

an array of left rail proximity sensors mounted to a left rail of a track;

an array of right rail proximity sensors mounted to a right rail of the track, forming a plurality of opposing pairs of sensors;

a control computer connected to the arrays to sense a wheel segment in a detection envelope pattern in a plurality of opposing pairs of sensors; and

wherein a deviation from a normal pattern determines a tracking error.

10. The system of claim 9, wherein the wheel segment in a detection envelope pattern further comprises a flange tip point (FTP) of a wheel either being outside the detection envelope or inside the detection envelope, thereby triggering a chosen output signal.

11. The system of claim 9 further comprising a railroad car identification system connected to the control computer to compare which railroad car has a wheel set with a tracking error.

12. A railroad car wheel tacking detection system comprising:

an array of proximity sensors mounted adjacent a rail of a track;

a computer connected to the array to sense a pattern of proximity sensor signals from a passing wheel; and

wherein the pattern is compared to a normal pattern to detect a tracking error.

13. A method to detect a tracking error in a passing wheel set of a railroad car, the method comprising the steps of:

placing a left array of proximity sensors along a left rail of a track;

placing a right array of proximity sensors along an opposite rail, wherein a series of opposing left and right sensors are formed;

connected a control computer to the arrays so as to sense a flange tip point (FTP) presence or absence in a detection envelope of each sensor;

passing a railroad car over the left and right rails so as to create a pattern of FTP presence/absence signals corresponding to wheel sets; and

detecting a tracking error by computing a chosen quantity of FTP absent signals from the passing wheel set.

14. The method of claim 13 further comprising the step of placing a railroad car identifying system having a wheel detector on the track, thereby enabling a computation of which railroad car has the tracking error in its wheel set.