Apparatus for estimating lateral forces of railroad vehicles

• US 9,637,148 B2
• Filed: 01/20/2015
• Issued: 05/02/2017
• Est. Priority Date: 01/27/2014
• Status: Active Grant

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: Jung, Jongchul, Cho, Yong Gee
• Primary Examiner(s): MUSTAFA, IMRAN K
• Application Number:
  US14/601,024
• Publication Number:
  US 20150210300A1
• Time in Patent Office: 833 Days
• CPC Class Codes: B61F 9/005 by use of non-mechanical means, e.g. acoustic or electromagnetic devices
• CPC Class Codes: B61L 15/0081 On-board diagnosis or maintenance
• CPC Class Codes: B61L 23/047 Track or rail movements

Abstract

The present disclosure relates to an apparatus and a method for estimating a lateral force applied to a bogie due to contact between a wheel and a rail when a railroad vehicle drives in a curved section, the apparatus including: a lateral velocity estimation observer configured to calculate a lateral velocity estimate by estimating a lateral velocity based on a vertical acceleration, a lateral acceleration, a yaw velocity, and a wheel angular velocity of the railroad vehicle; and a lateral force estimation observer configured to calculate a lateral force estimate, by estimating a lateral force applied to a bogie of the railroad vehicle based on a steering angle of the railroad vehicle, a vertical force applied to the railroad vehicle, and a lateral velocity estimate calculated by the lateral velocity estimation observer.

Claims

1. An apparatus for estimating a lateral force of a railroad vehicle, the apparatus comprising:

a lateral velocity estimation observer configured to calculate a lateral velocity estimate by estimating a lateral velocity based on a vertical acceleration, a lateral acceleration, a yaw velocity, and a wheel angular velocity of the railroad vehicle; and

a lateral force estimation observer configured to calculate a lateral force estimate by estimating a lateral force applied to a bogie of the railroad vehicle based on a steering angle of the railroad vehicle, a vertical force applied to the railroad vehicle, and a lateral velocity estimate calculated by the lateral velocity estimation observer,

wherein the lateral velocity estimation observer includes;

a vertical velocity calculator configured to calculate a vertical velocity of the railroad vehicle by averaging a front wheel angular velocity and a rear wheel angular velocity measured by a wheel sensor; and

a lateral velocity estimator configured to calculate the lateral velocity estimate based on the vertical acceleration, the lateral acceleration, and the yaw velocity measured by a body sensor and further based on a vertical velocity calculated by the vertical velocity calculator.

2. The apparatus of claim 1, wherein:

the lateral velocity estimation observer calculates the lateral velocity estimate using a Kalman filter; and

the lateral force estimation observer calculates the lateral force estimate using an extended Kalman filter.

3. The apparatus of claim 1, wherein the lateral velocity estimate ({circumflex over (v)}_y(k)) is calculated by the following equation:

{circumflex over (v)}_y(k)=[0 1]{circumflex over (x)}(k|k),

where {circumflex over (v)}_y(k) is a lateral velocity estimate of the railroad vehicle estimated in kth step and {circumflex over (x)}(k|k) is a state variable estimate in kth step.

4. The apparatus of claim 1, wherein the lateral force estimate ({circumflex over (F)}_yƒ

(k),{circumflex over (F)}_yr(k)) is calculated by the following equation;

5. A method for estimating a lateral force of a railroad vehicle, the method comprising:

calculating a vertical velocity estimate by estimating a lateral velocity based on a vertical acceleration, a lateral acceleration, a yaw velocity and a wheel angular velocity of the railroad vehicle;

and

calculating a lateral force estimate by estimating a lateral force applied to a bogie of the railroad vehicle based on a steering angle of the railroad vehicle, a vertical force applied to the railroad vehicle, and a lateral velocity estimate,

wherein the lateral velocity estimate is calculated by a lateral velocity estimation observer that includes;

a vertical velocity calculator configured to calculate a vertical velocity of the railroad vehicle by averaging a front wheel angular velocity and a rear wheel angular velocity measured by a wheel sensor; and

a lateral velocity estimator configured to calculate the lateral velocity estimate based on the vertical acceleration, the lateral acceleration, and the yaw velocity measured by a body sensor and further based on a vertical velocity calculated by the vertical velocity calculator.

6. The method of claim 5, wherein the lateral velocity estimate is calculated by using a state variable estimated in kth step calibrated by using an estimation error with respect to an output variable between a kth state variable estimate predicted in k−

1th step and a value measured in kth step, as in the following equation;

{circumflex over (v)}_y(k)=[0 1]{circumflex over (x)}(k|k),

where {circumflex over (v)}_y(k) is a lateral velocity estimate of the railroad vehicle estimated in kth step; and

{circumflex over (x)}(k|k) is a state variable estimate in kth step.

7. The method of claim 5, wherein the lateral force estimate is calculated by calculating an estimate of lateral force applied to a front wheel bogie and an estimate of lateral force applied to a rear wheel bogie in kth and by applying a state variable estimate in kth step to the following equation: