System And Method For Monitoring Braking Effort

• US 20150025737A1
• Filed: 07/22/2013
• Published: 01/22/2015
• Est. Priority Date: 07/22/2013
• Status: Active Grant

• Current Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: General Electric Company
• Inventors: Kumar, Ajith Kuttannair, Hermsen, Bryan Scott, Matthews, Harry Kirk Jr., Down, John Harry, Meyer, Brian Nedward
• Granted Patent: US 9,150,209 B2
• Time in Patent Office: Days
• US Class Current: 701/33.9
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M

Abstract

A method (e.g., for monitoring a braking system of a vehicle system) includes monitoring fluid pressures of a braking system and modeled braking efforts of the braking system in a vehicle system traveling along a route, identifying one or more time periods at least one of before a brake event of the braking system or after the brake event, calculating residual forces exerted on the vehicle system during the one or more time periods, and determining at least one of an estimated braking effort of the braking system or an estimated propagation rate at which the estimated braking effort is applied by the braking system using the residual forces that are calculated.

Claims

1. A method comprising:

monitoring fluid pressures of a braking system and modeled braking efforts of the braking system in a vehicle system traveling along a route;

identifying one or more time periods at least one of before a brake event of the braking system or after the brake event;

calculating residual forces exerted on the vehicle system during the one or more time periods; and

determining at least one of an estimated braking effort of the braking system or an estimated propagation rate at which the estimated braking effort is applied by the braking system using the residual forces that are calculated.

2. The method of claim 1, wherein the estimated braking effort is determined by calculating a difference between the residual forces calculated for a first time period of the one or more time periods that occurs before the brake event and the residual forces calculated for a second time period of the one or more time periods that occurs after the brake event.

3. The method of claim 1, wherein the estimated propagation rate is determined by calculating a rate at which the residual forces change within a designated propagation window time period following the brake event.

4. The method of claim 1, wherein the one or more time periods are steady state time periods identified by determining when the fluid pressures do not change by more than a first designated threshold amount for at least a designated time period and when the modeled braking efforts also do not change by more than a second designated threshold amount for at least the same designated time period.

5. The method of claim 1, wherein the brake event represents activation of the braking system by changing the fluid pressures of fluid stored in a reservoir of the braking system.

6. The method of claim 1, wherein the estimated propagation rate is determined only when at least one of a throttle setting or a brake setting of the vehicle system does not change during a designated, non-zero propagation window time period following the brake event.

7. The method of claim 1, wherein the estimated propagation rate is determined even if at least one of a throttle setting or a brake setting of the vehicle system changes during a designated, non-zero propagation window time period following the brake event.

8. The method of claim 1, further comprising revising a trip plan of a trip of the vehicle system along the route responsive to at least one of the estimated braking effort deviating from an assumed braking effort by at least a first threshold amount or the estimated propagation rate deviating from an assumed propagation rate by at least a second threshold amount, the trip plan designating operational settings of the vehicle system as a function of at least one of time or distance along the route, the trip plan created using at least one of the assumed braking effort or the assumed propagation rate.

9. A control system comprising:

a vehicle controller configured to monitor fluid pressures of a braking system and modeled braking efforts of the braking system in a vehicle system traveling along a route, the vehicle controller also configured to identify one or more time periods at least one of before a brake event of the braking system or after the brake event, the vehicle controller further configured to calculate residual forces exerted on the vehicle system during the one or more time periods and determine at least one of an estimated braking effort of the braking system or an estimated propagation rate at which the estimated braking effort is applied by the braking system using the residual forces that are calculated.

10. The control system of claim 9, wherein the vehicle controller is configured to determine the estimated braking effort by calculating a difference between the residual forces calculated for a first time period of the one or more time periods that occurs before the brake event and the residual forces calculated for a second time period of the one or more time periods that occurs after the brake event.

11. The control system of claim 9, wherein the vehicle controller is configured to determine the estimated propagation rate by calculating a rate at which the residual forces change within a designated propagation window time period following the brake event.

12. The control system of claim 9, wherein the vehicle controller is configured to identify the one or more time periods by determining when the fluid pressures do not change by more than a first designated threshold amount for at least a designated time period and when the modeled braking efforts also do not change by more than a second designated threshold amount for at least the same designated time period.

13. The control system of claim 9, wherein the brake event represents activation of the braking system by changing the fluid pressures of fluid stored in a reservoir of the braking system.

14. The control system of claim 9, wherein the vehicle controller is configured to determine the estimated propagation rate only when at least one of a throttle setting or a brake setting of the vehicle system does not change during a designated, non-zero propagation window time period following the brake event.

15. The control system of claim 9, further comprising an energy management system configured to revise a trip plan of a trip of the vehicle system along the route responsive to at least one of the estimated braking effort deviating from an assumed braking effort by at least a first threshold amount or the estimated propagation rate deviating from an assumed propagation rate by at least a second threshold amount, the trip plan designating operational settings of the vehicle system as a function of at least one of time or distance along the route, the trip plan created using at least one of the assumed braking effort or the assumed propagation rate.

16. A method comprising:

measuring air pressures of an air braking system of a vehicle system before and after a brake event representing activation of the air braking system;

modeling braking efforts provided by the air braking system before and after the brake event;

identifying a pre-brake event time period when both the air pressures do not vary by more than a first threshold amount and the braking efforts that are modeled do not vary by more than a second threshold amount;

calculating pre-brake event residual forces exerted on the vehicle system during the pre-brake event time period; and

estimating at least one of an actual braking effort of the air braking system or a propagation rate at which the actual braking effort is applied by the air braking system using the residual forces that are calculated.

17. The method of claim 16, further comprising:

identifying a post-brake event time period when both the air pressures do not vary by more than the first threshold amount and the braking efforts that are modeled do not vary by more than the second threshold amount; and

calculating post-brake event residual forces exerted on the vehicle system during the post-brake event time period, wherein the actual braking effort is estimated by calculating a difference between the pre-brake event residual forces and the post-brake event residual forces.

18. The method of claim 16, further comprising:

identifying a post-brake event propagation window following the brake event;

calculating propagation window residual forces occurring during the post-brake event propagation window; and

identifying a rate of change in a difference between the propagation window residual forces and the pre-brake event residual forces as the estimated propagation rate.

19. The method of claim 16, further comprising notifying an operator of the vehicle system to not activate the braking system responsive to at least one of the estimated braking effort being less than an assumed braking effort or the estimated propagation rate being slower than an assumed braking rate.

20. The method of claim 16, further comprising revising a trip plan of a trip of the vehicle system along a route responsive to at least one of the estimated braking effort being less than an assumed braking effort by at least a threshold amount or the estimated propagation rate being slower than an assumed propagation rate by at least a threshold rate, the trip plan designating operational settings of the vehicle system as a function of at least one of time or distance along the route, the trip plan created using at least one of the assumed braking effort or the assumed propagation rate.

21. The method of claim 16, wherein the braking efforts that are modeled represent forces that are expected to be provided by the braking system based on one or more input values representative of characteristics of at least one of the vehicle system or a route being traveled by the vehicle system.