APPARATUS FOR ESTIMATING LATERAL FORCES OF RAILROAD VEHICLES

• US 20150210300A1
• Filed: 01/20/2015
• Published: 07/30/2015
• 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
• Granted Patent: US 9,637,148 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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.

2. The apparatus of claim 1, wherein the lateral velocity estimation observer includes:

a vertical velocity calculator configured to calculate a vertical velocity of the railroad vehicle based on 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 based on a vertical velocity calculated by the vertical velocity calculator.

3. 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.

4. 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.

5. The apparatus of claim 1, wherein the lateral force estimate ({circumflex over (F)}_yf(k),{circumflex over (F)}_yr(k)) is calculated by the following equation:

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

calculating a vertical velocity by using a front wheel angular velocity and a rear wheel angular velocity of the railroad vehicle;

calculating a lateral velocity estimate by applying a vertical acceleration, a lateral acceleration, and a yaw velocity of the railroad vehicle, and the vertical velocity to a Kalman filter; and

calculating a lateral force estimate, by estimating a lateral force applied to a bogie of the railroad vehicle by applying a steering angle of the railroad vehicle, a vertical force applied to a wheel of the railroad vehicle, and the lateral velocity estimate to an extended Kalman filter.

7. The method of claim 6, 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;

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.

8. The method of claim 6, wherein the lateral force estimate is calculated by calculating an estimate of lateral force applied to a front wheel bogie in kth step and an estimate of lateral force applied to a rear wheel bogie in kth step, by applying a state variable estimate in kth step to the following equation: