Method and system for axle evaluation and tuning with loading system and vehicle model

• US 20080275682A1
• Filed: 05/04/2007
• Published: 11/06/2008
• Est. Priority Date: 05/04/2007
• Status: Abandoned Application

• Current Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Original Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Inventors: Langer, William J.
• Application Number:
  US11/800,526
• Publication Number:
  US 20080275682A1
• Time in Patent Office: Days
• US Class Current: 703/8
• CPC Class Codes: G01M 17/0072 the wheels of the vehicle co-operating with rotatable rolls G01M17/022, G01M17/045, G01M17/065 take precedence

Abstract

A method and system for evaluating and tuning axle systems includes at least one test rig on which one or more physical axle systems are mounted. A full vehicle model and a road description are used with the test rig to test and evaluate or tune the axle system as would be conducted on a real test track. The full vehicle model is modified to remove the characteristics of the axle system under test. The remainder of the full vehicle model produces output signals in the form of displacements or loads that are transmitted as inputs to the test rig to apply those signals. The test rig measures output signals in the form of complementary displacements or loads that will become inputs to the vehicle model in place of the removed model of the axle system under test. In this manner, the physical axle system under test is inserted into a real time model of the full vehicle, road and driver.

Claims

1. A system for evaluating axle systems and vehicle performance, comprising:

at least one test rig on which at least one axle system under test is mountable, the test rig controllably applying loads on the axle system under test; and

a vehicle model module that includes;

a data processor for processing data; and

a data storage device configured to store;

data related to a vehicle model that simulates a full vehicle except for characteristics of the axle system under test;

data related to a road description;

driving instructions, human driver control, and machine-executable instructions, wherein the instructions, upon execution by the data processor, control the vehicle model module to produce command signals based on the vehicle model and the road description to control the test rig to apply loads on the axle system and to feed back measured responses of the test rig to the vehicle model.

2. The system of claim 1, further comprising a supervisor coupled to the vehicle model module and to the test rig, the supervisor comprising a data processor configured to coordinate the vehicle model and the test rig, provide the command signals to the test rig and provide the measured responses to the vehicle model.

3. The system of claim 1, wherein the human driver control component of the vehicle model is configured to operate open loop with respect to at least one of speed, course, position, behavior, or condition of the vehicle.

4. The system of claim 1, wherein the human driver control component of the vehicle model is configured to operate closed loop with respect to a speed and course of the vehicle.

5. The system of claim 1, wherein the full vehicle model includes modeling of:

engine;

powertrain, tires, vehicle dynamics, aerodynamics, driver and road.

6. The system of claim 5, wherein the full vehicle model includes models of axle systems that are not physically present in the test rig.

7. The system of claim 6, wherein the data processor is configure to model the full vehicle by a converging iterative process to virtually move the axle system under test to different positions on the vehicle model.

8. The system of claim 1, wherein the data related to the road description includes roadway surface definition including at least one of the parameters:

coefficient of friction, roughness, slope, curvature, obstacle profiles, bump profiles and temperature.

9. The system of claim 1, wherein the test rig includes at least one loading actuator that is controllable to apply positions and angles to the axle system.

10. The system of claim 9, wherein the test rig includes a plurality of the loading actuators, wherein each loading actuator is independently controllable.

11. The system of claim 9, wherein the positions and angles include at least one of:

body z, γ

;

road z(2), road α

(2), road v(2), and steer wheel position.

12. The system of claim 1, wherein the test rig includes a moment input fixture controllable to input a moment on the axle component.

13. The system of claim 2, wherein the supervisor and the vehicle model module are configured for coupling to different component test rigs for other vehicle components to interact with the different component test rigs and integrating in the vehicle model results from the different component test rigs and the test rig on which the axle system under test is mounted.

14. A method of evaluating axle systems and predicting vehicle performance, comprising:

mounting at least one axle system on at least one test rig;

modeling a road environment, human driver and vehicle model that is a full vehicle model excluding the axle system on the test rig;

determining state and motion of the modeled vehicle model over a road;

generating command signals to the test rig based on the vehicle model and its state as at least one of displacement and load control signals;

applying at least one of displacements and loads to the axle system with the test rig in accordance with the command signals;

measuring at least one of resulting displacements or loads of the axle system at the test rig; and

providing at least one of measured complementary displacements or loads to the vehicle model.

15. The method of claim 14, wherein the vehicle model is executed in real time.

16. The method of claim 14, wherein the axle system loads are provided to the test rig substantially synchronously with the vehicle model.

17. The method of claim 15, wherein a plurality of physical axle systems of a vehicle are mounted on at least one test rig and simultaneously evaluated.

18. The method of claim 15, further comprising simultaneously controlling a plurality of test rigs on which axle systems are mounted.

19. The method of claim 15, further comprising controlling inputs to test rigs on which are mounted physical vehicle components other than axle systems, and receiving outputs from the test rigs and providing the outputs to the vehicle model.

20. The method of claim 15, further comprising subjecting the axle systems to environmental conditions.

21. The method of claim 15, wherein the step of applying at least one of displacements and loads to the axle system with the test rig includes axially loading the axle system with a loading actuator.

22. The method of claim 21, wherein the test rig includes a plurality of the loading actuators, wherein each loading actuator is independently controllable to axially load the respective axle system.

23. The method of claim 15, wherein the step of applying at least one of displacements and loads to the axle system with the test rig includes inputting a moment on the axle system with a moment input fixture.