Method for determining at least one speed in a rail vehicle

Patent metadata

Field	Value
Publication number	US-10459001-B2
Application number	US-201414893955-A
Country	US
Kind code	B2
Filing date	May 26, 2014
Priority date	Jun 4, 2013
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A speed of a rail vehicle equipped with a first chassis unit is determined. A chassis speed measurement variable is provided by a sensor unit. Inertial measurement variables are detected by an inertial measurement unit; a reference speed characteristic value is formed; an inertial speed characteristic value is determined by a calculation unit based on the inertial measurement variables, in a first operating mode, to estimate a deviation in the inertial calculation based on the reference speed characteristic value; the inertial speed characteristic value is determined, in a second operating mode, without taking into account the reference speed characteristic value. If an anomalous provision process of the chassis speed measurement variable is detected by a recognition unit on the basis of a reference characteristic value and the chassis speed measurement value, the inertial calculation is performed according to the second operating mode.

First claim

The invention claimed is:

1. A method for determining a speed of a rail vehicle equipped with at least one first chassis supporting a carriage of the rail vehicle and for applying a brake of the rail vehicle, the method comprising:
providing, with a sensor associated with the first chassis, at least one chassis speed measurement variable related to the first chassis;
recording inertial measurement variables by an inertial measuring unit;
forming a reference speed characteristic variable based on the chassis speed measurement variable;
determining an inertial speed characteristic variable by carrying out an inertial calculation with at least one computing unit, at least based on the inertial measurement variables and, during at least one period according to a first operating mode, based on the reference speed characteristic variable in order to estimate a deviation in the inertial calculation;
determining the inertial speed characteristic variable, by way of the inertial calculation, at least based on the inertial measurement variables and, during at least one period according to a second operating mode, without taking into account the reference speed characteristic variable;
with a detection unit, detecting an abnormal process of providing the chassis speed measurement variable based on a reference characteristic variable and the chassis speed measurement variable;
upon detecting the abnormal process of providing the chassis speed measurement variable, carrying out the inertial calculation according to the second operating mode;
assigning a plurality of computing units to the first chassis, each computing unit being able to respectively carry out the inertial calculation according to the operating modes and providing a result of the inertial calculation at an output;
assigning a switching apparatus to the computing units, wherein said switching apparatus is selectively connected to one of the outputs in order to provide the inertial speed characteristic variable;
connecting a respective switching unit, which has a first switching state and a second switching state, upstream of each computing unit, wherein in the first switching state, the switching unit provides the reference speed characteristic variable for the respective computing unit for carrying out the first operating mode and wherein in the second switching state, the switching unit decouples the respective computing unit from the reference speed characteristic variable in order to carry out the second operating mode;
if an abnormal recording process is not present, matching respective switching cycles of the switching units and a switching cycle of the switching apparatus to one another so that the switching apparatus, during each switching process, establishes a connection to the at least one computing unit which carries out the inertial calculation according to the second operating mode;
if an abnormal recording process is present, all switching units are switched in the second switching state; and
applying the brake at least dependent on a magnitude of the inertial speed characteristic variable.

2. The method according to claim 1 , which comprises:
determining, with a first computing component of the computing unit, an estimated value of the inertial speed characteristic variable from the inertial measurement variables;
with a second computing component of the computing unit which forms a state observer, estimating the deviation in the first operating mode based on the estimated value and the reference speed characteristic variable; and
using the deviation estimated by the second computing component in the first computing component.

3. The method according to claim 1 , wherein, in a first embodiment of the first operating mode, the reference speed characteristic variable corresponds to the chassis speed measurement variable.

4. The method according to claim 2 , which comprises operating the state observer in a free propagation mode in the second operating mode.

5. The method according to claim 1 , wherein, in a second embodiment of the first operating mode, providing a global speed characteristic variable and forming the reference speed characteristic variable based on the chassis speed measurement variable and the global speed characteristic variable, wherein the global speed characteristic variable is based on dynamics of an entire rail vehicle.

6. The method according to claim 2 , which comprises, in the second operating mode, estimating the deviation with the second computing component based on the global speed characteristic variable.

7. The method according to claim 5 , which comprises providing the global speed characteristic variable at least on a basis of an averaging of speed characteristic variables of a plurality of chassis each different from the first chassis.

8. The method according to claim 5 , wherein the rail vehicle has a global recording apparatus which is different from the inertial measuring unit and which provides the global speed characteristic variable.

9. The method according to claim 5 , which comprises providing a merging module implementing a Kalman filter, supplying the global speed characteristic variable and the chassis speed measurement variable to the merging module, and obtaining the reference speed characteristic variable from the merging module.

10. The method according to claim 6 , wherein the switching units, in the second switching state thereof, provide the global speed characteristic variable for the respective computing unit for carrying out the second operating mode.

11. The method according to claim 1 , which comprises, if an abnormal recording process is not present, matching the switching cycles of the switching units and the switching cycle of the switching apparatus to one another so that the switching apparatus, during each switching process, establishes a connection to one of the computing units which has been carrying out the inertial calculation according to the second operating mode at least for a predetermined time.

12. The method according to claim 6 , which comprises, in a wheel diameter determination mode, carrying out the inertial calculation according to the second operating mode for determining the inertial speed characteristic variable, and determining at least one wheel diameter characteristic variable of the chassis at least based on the inertial speed characteristic variable determined in the second operating mode.

13. The method according to claim 12 , which comprises, in the inertial calculation according to the first operating mode following the wheel diameter determination mode, providing the chassis speed measurement variable by taking into account the wheel diameter characteristic variable determined in the wheel diameter determination mode.

14. The method according to claim 1 , wherein the chassis is a bogie.

15. The method according to claim 1 , which comprises providing a global reference speed characteristic variable to the computing unit instead of the reference speed characteristic variable in the second operating mode.

16. The method according to claim 1 , wherein the step of applying the brake is also dependent on braking power applied by at least one drive motor of the rail vehicle.

Assignees

• Siemens Mobility GmbH

Inventors

• Foerster Till
• Hassler Stefan
• Stuetzle Thorsten

Classifications

• G01P7/00 Primary

  Measuring speed by integrating acceleration (measuring travelled distance by double integration of acceleration G01C21/16) · CPC title

• B60T13/665

  the systems being specially adapted for transferring two or more command signals, e.g. railway systems (B60T13/662 takes precedence) · CPC title

• B60T8/172

  Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters {(B60T8/17551 takes precedence)} · CPC title

• B60T8/1705

  for rail vehicles · CPC title

• G01P21/02

  of speedometers · CPC title