Method for simulating cornering

Patent metadata

Field	Value
Publication number	US-10161832-B2
Application number	US-201414914505-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A method for simulating cornering of a vehicle 2 being tested on a roller dynamometer 1 to determine a measured variable 13, wherein the vehicle 2 being tested on the roller dynamometer 1 is operated as though driving straight ahead, and to simulate cornering the additional resistance forces of cornering are taken into account in the form of a correction parameter 9.

First claim

The invention claimed is:

1. A method for accounting for simulated cornering of a vehicle being tested on a roller dynamometer in a measured variable:
operating the vehicle on the roller dynamometer as though the vehicle is driving straight ahead with all wheels having the same rotational speed;
determine a correction parameter by simulating cornering the vehicle on the roller dynamometer, the correction parameter associated with additional resistance forces on the vehicle due to cornering; and
determine the measured variable based at least in part on the correction parameter.

2. The method according to claim 1 , wherein a cumulative resistance force, associated with the simulated cornering of the vehicle, is used as the correction parameter, the cumulative resistance force is formed by adding the additional resistance forces exerted on the vehicle during cornering, said cumulative resistance force being taken into account on the roller dynamometer in the form of a modified resistance which the roller dynamometer exerts on the vehicle.

3. The method according to claim 2 , wherein a characteristic map which describes the correction parameter is compiled by real coast down experiments of the vehicle being tested, in curves with different radii (R).

4. The method according to claim 2 , wherein the correction parameter is calculated using one or more physical models.

5. The method according to claim 4 , wherein a first physical model is used to take into account the resistance forces created by the forces acting on tires and a chassis of the vehicle being tested.

6. The method according to claim 4 , wherein a second physical model is used to take into account the resistance forces created by losses in a drive train of the vehicle being tested.

7. The method according to claim 4 , wherein a third physical model is used to take into account resistance forces which are created by auxiliary units of the vehicle being tested which are dependent on steering.

8. The method according to claim 1 , wherein a mathematical correction factor is used as the correction parameter, wherein the measured variable is corrected by means of the correction factor.

9. The method according to claim 1 , wherein the correction parameter is calculated using one or more physical models including:
a first physical model is used to take into account resistance forces created by the forces acting on tires and a chassis of the vehicle being tested,
a second physical model is used to take into account resistance forces created by losses in a drive train of the vehicle being tested, and
a third physical model is used to take into account resistance forces which are created by auxiliary units of the vehicle being tested which are dependent on steering; and
wherein the resistance forces measured by the one or more physical models are added to determine the correction parameter for the simulated cornering of the vehicle.

10. The method of claim 1 , wherein the additional resistance forces on the vehicle during cornering include one or more of the following: slippage on tires of the vehicle, losses in a differential of the vehicle, losses from a power steering unit, and other losses from driven auxiliary components.

11. The method of claim 1 , wherein the roller dynamometer is a 4×2 or 2×1 roller dynamometer.

12. The method of claim 1 , wherein the correction parameter accounts for and accumulates simulated resistance forces associated with the vehicle cornering, and an increased resistance is applied to the roller dynamometer in response to an increased correction parameter, the correction parameter includes simulated resistance forces for one or more of the following: slippage on tires of the vehicle, losses in a differential of the vehicle, losses from a power steering unit, and other losses from driven auxiliary components.

13. The method of claim 1 , wherein the measured variable is one or more of the following: fuel consumption, exhaust certification, or various other performance characteristics of the vehicle.

14. The method of claim 1 , wherein the correction parameter is representative of a cumulative resistive force associated with the vehicle cornering, and the method of claim 1 further includes modifying the resistance the roller dynamometer exerts on the vehicle being tested, based on the determined correction parameter, before determining the measured variable.

15. The method of claim 1 , wherein the method further includes correcting the measured variable to account for the simulated cornering of the vehicle by applying the correction parameter to the measured variable to generate a corrected variable.

16. The method of claim 15 , wherein the correction parameter is calculated using a characteristic map for cornering resistance based on vehicle speed and curve radius.

17. The method of claim 1 , wherein the additional resistance forces on the vehicle due to cornering includes a cornering resistance measured by:

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Assignees

• Avl List Gmbh

Inventors

• Düser Tobias
• Hettel Rolf

Classifications

• G01M17/0072 Primary

  the wheels of the vehicle co-operating with rotatable rolls (G01M17/022, G01M17/045, G01M17/065 take precedence) · CPC title

• G01M17/065 Primary

  the vehicle wheels co-operating with rotatable rolls · CPC title