Apparatus for and method of testing dynamic characteristics of components of vehicle

• US 6,247,348 B1
• Filed: 04/03/1998
• Issued: 06/19/2001
• Est. Priority Date: 04/04/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi Plant Technologies Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamakado, Makoto, Horiuchi, Toshihiko, Yamagishi, Wataru, Konno, Takao
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US09/054,391
• Time in Patent Office: 1,173 Days
• Field of Search: 73/110.4, 731/17, 731/24, 731/28, 731/18
• US Class Current: 73/11.04
• CPC Class Codes: G01M 17/045 the vehicle wheels co-operating with rotatable rollers

Abstract

Measured values obtained from a running test of an object to be tested and a module on a test bench such as a flat belt type chassis dynamo, and computation based upon numerical models of components other than the object to be tested and the module, are related to each other so as to reproduce a condition near to an actual running condition, for the object to be tested and the module so as to precisely analyze how the object to be tested and the module affects upon the motion of the overall vehicle during actual running of the vehicle. Thus it is possible to evaluate dynamic characteristics of respective vehicle components and a module which relate to the maneuvering performance of the vehicle, on a test bench in a condition in which a load variation and an alignment variation are taken into consideration.

Claims

1. A vehicle component dynamic test apparatus, comprising:

a frame supported on a base;

a plurality of actuators connected to said frame, for supporting a dummy chassis which carries thereon a component of said vehicle to be tested including at least one wheel;

a dummy road surface means for supporting the base and having a dummy road surface adapted to simulate a road surface on which the vehicle runs;

a first control means for the dummy road surface;

a reaction force measuring means for measuring a reaction force produced when the wheel of the component makes contact with the dummy road surface;

an attitude detecting means comprising displacement detectors provided respectively for each of the-actuators, for detecting an attitude of the dummy chassis with respect to the frame;

second control means for the actuators;

numerical model storage means for storing numerical models of the vehicle; and

a computer electrically coupled to said reaction force measuring means, said numerical model storage means, said attitude detecting means and said first and second control means for computing an attitude of the dummy chassis and a load applied to the road surface from each of wheels of the vehicle, from a measured reaction force delivered from the reaction force measuring means with the use of the numerical models stored in the numerical mode storage means, and for delivering instruction signals to the second control means for the actuators and the first control means for the dummy road surface means so as to decrease a difference between the attitude of the dummy chassis detected by the attitude detecting means and the computed attitude of the dummy chassis, and to decrease a difference between a load applied to the dummy road surface, which is obtained from the reaction force of the wheel corresponding to the component to be tested, measured by the reaction force measuring means, and the calculated load which would be applied to the road surface by the first wheel corresponding to the component.

2. A vehicle component dynamic test apparatus as set forth in claim 1, wherein said reaction force measuring means can measure said reaction force from decomposed components longitudinal, crosswise and vertical of the road surface.

3. A vehicle component dynamic test apparatus as set forth in claims 1 or 2, wherein if the reaction force measuring means measures a longitudinal component from the dummy road surface, a rotational displacement about a rotary axis crosswise of the dummy road surface is preferably applied to the dummy chassis by the actuators.

4. A vehicle component dynamic test apparatus as set forth in claim 1, wherein if the reaction force measuring means measures a crosswise component from the dummy road surface, an angular displacement about a rotary axis longitudinal of the dummy road surface is applied to the dummy chassis by the actuators.

5. A vehicle component dynamic test apparatus as set forth in claim 1, wherein the dummy road surface is formed of a flat-belt type chassis dynamo, and the reaction force measuring means measures a longitudinal reaction force of the dummy road surface as a value which is computed from rotating data including a rotational inertia of the flat-belt type chassis dynamo, an absorbing/generating torque, a rotational speed, and an angular acceleration of a motor/generator for driving the chassis dynamo.

6. A vehicle component dynamic test apparatus according to claim 1, wherein the computer is a digital computer.

7. A dynamic test method for a component of a vehicle, comprising the steps of:

supporting a dummy chassis with a plurality of actuators connected to a frame;

supporting the component of the vehicle as an object to be tested, which component includes at least a first wheel, on the dummy chassis;

calculating forces produced by second wheels other than the first wheel corresponding to the component, and calculating a force generated from the first wheel as an object to be tested, from at least either one of data of reaction on a dummy road surface and data of rotation of the dummy road surface, and calculating a force acting upon the vehicle from a resultant force of these forces generated at the first wheel and the second wheels;

calculating a load effected at the first wheel; and

loads effected at the second wheels, with the use of a numerical model of the vehicle;

driving the actuators so as to apply the thus calculated loads to the first wheel in order to establish a stroke and an alignment of an assembly of the first wheel;

calculating strokes and alignments of assemblies of the second wheels, with the use of the numerical model of the vehicle; and

driving the actuators in accordance with the stroke and the alignment of the assembly of the first wheel, which have been established, and the stroke and the alignments of the second wheels other than the first wheel, which have been calculated, so as to adjust an attitude of the dummy chassis to an attitude of the vehicle.

8. A step as set forth in claim 7, wherein the attitude of the dummy chassis is detected by detecting displacements of each of the actuators.

9. A vehicle component dynamic test apparatus, comprising:

a frame supported on a base;

a plurality of actuators connected to said frame, which support a dummy chassis which carries thereon a component of said vehicle to be tested including at least one wheel;

a dummy road surface simulator supported on the base and having a dummy road surface adapted to simulate a road surface on which the vehicle runs;

a first control device for the dummy road surface;

a reaction force measuring element which measures a reaction force produced when the wheel of the component makes contact with the dummy road surface;

an attitude detecting device comprising displacement detectors provided respectively for each of the actuators, which detects an attitude of the dummy chassis with respect to the frame;

a second control device for the actuators;

a numerical model storage device which stores numerical models of the vehicle; and

a computer electrically coupled to said reaction force measuring device, said numerical model storage device, said attitude detecting device and said first and second control devices for computing an attitude of the dummy chassis and a load applied to the road surface from each of wheels of the vehicle, from a measured reaction force delivered from the reaction force measuring device with the use of the numerical models stored in the numerical model storage device, and for delivering instruction signals to the second control device for the actuators and the first control device for the dummy road surface simulator so as to decrease a difference between the attitude of the dummy chassis detected by the attitude detecting device and the computed attitude of the dummy chassis, and to decrease a difference between a load applied to the dummy road surface, which is obtained from the reaction force of the wheel corresponding to the component to be tested, measured by the reaction force measuring device, and the calculated load which would be applied to the road surface by the first wheel corresponding to the component.

10. A vehicle component dynamic test apparatus according to claim 9, wherein the computer is a digital computer.