Apparatus for testing the wheel suspension of a vehicle

• US 5,259,246 A
• Filed: 09/10/1991
• Issued: 11/09/1993
• Est. Priority Date: 09/10/1990
• Status: Expired due to Term

• Current Assignee: Steitz Holding A.V.V.
• Original Assignee: Analogic Engineering B.V.
• Inventors: Stuyts, Victor C. L. H.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Finley, Rose M.
• Application Number:
  US07/757,337
• Time in Patent Office: 791 Days
• Field of Search: 73/11, 73/669, 73/660
• US Class Current: 73/669
• CPC Class Codes: B60G 2206/99 Suspension element selection procedure depending on loading or performance requirements, e.g. selection of damper, spring or bush
• CPC Class Codes: G01M 17/04 Suspension or damping

Abstract

Apparatus for testing a wheel suspension of a vehicle, comprising at least one measuring plate adapted to be moved by an excitation mechanism, a first measuring device for each measuring plate for measuring vertical forces exerted by an air tire of the vehicle on the measuring plate, a processing unit for processing measured values provided by the first measuring device and a display unit for displaying a measuring result. Further, a second measuring device is provided for measuring a selected one of a position, velocity and acceleration of the measuring plate. The processing unit being adapted to determine a transfer function of the wheel suspension from the measuring values of the first measured device and measured values of the second measuring device, the wheel suspension comprising a plurality of system elements, each of the system elements carrying a system value. The processing unit being adapted to compute values of the system elements from the transfer function the processing unit being adapted to utilize the system values to further compute at least one evaluation variable, and adapted to compare the evaluation variable with a stored evaluation variable, the processing unit being further adapted to estimate a final evaluation of the wheel suspension from the comparison, and the display unit being adapted to display the final evaluation.

Claims

1. Apparatus for testing a wheel suspension of a vehicle, comprising:

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle on said measuring plate,

a processing unit for processing measured values provided by said first measuring means,

a display unit for displaying a measuring result,

and a second measuring means for measuring a selected one of a position, velocity and acceleration of said measuring plate,

said processing unit being adapted to determine a transfer function of said wheel suspension from said measured values of said first measuring means and measured values of said second measuring means,

said wheel suspension comprising a plurality of system elements, each of said system elements carrying a system value,

said processing unit being adapted to compute by means of an additional equivalent model of said system values of said system elements from said transfer function,

said processing unit being adapted to utilize said system values to further compute at least one evaluation variable, and adapted to compare said evaluation variable with a stored evaluation variable, said processing unit being further adapted to estimate a final evaluation of said wheel suspension from said comparison, and

said display unit being adapted to display said final evaluation.

2. Apparatus for testing a wheel suspension of a vehicle, comprising:

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle on said measuring plate,

a processing unit for processing measured values provided by said first measuring means,

a display unit for displaying a measuring result,

and a second measuring means for measuring a selected one of a position, velocity and acceleration of said measuring plate,

said processing unit being adapted to determine a transfer function of said wheel suspension from said measured values of said first measuring means and measured values of said second measuring means,

said wheel suspension comprising a plurality of system elements, each of said system elements carrying a system value,

said processing unit being adapted to compute by means of an additional equivalent model of said system values of said system elements from said transfer function,

said processing unit being adapted to utilize said system values to further compute at least one evaluation variable, and adapted to compare said evaluation variable with a stored evaluation variable, said processing unit being further adapted to estimate a final evaluation of said wheel suspension from said comparison, wherein said processing unit being adapted to replace one or more of said computer system values of said system elements by a standard value of a corresponding system element, for example a value of said air tire with a correct stiffness, whereafter said processing unit being adapted to compute with a standard value a corrected value for each of said evaluation variables and being further adapted to compare said corrected system value with said stored value for each of said evaluation variables to obtain an evaluation of said wheel suspension.

said display unit being adapted to display said final evaluation.

3. Apparatus for testing a wheel suspension of a vehicle, comprising:

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle on said measuring plate,

a processing unit for processing measured values provided by said first measuring means,

a display unit for displaying a measuring result,

and a second measuring means for measuring a selected one of a position, velocity and acceleration of said measuring plate,

said processing unit being adapted to determine a transfer function of said wheel suspension from said measured values of said first measuring means and measured values of said second measuring means,

said wheel suspension comprising a plurality of system elements, each of said system elements carrying a system value,

said processing unit being adapted to compute by means of an additional equivalent model of said system values of said system elements from said transfer function,

said processing unit being adapted to utilize said system values to further compute at least one evaluation variable, and adapted to compare said evaluation variable with a stored evaluation variable, said processing unit being further adapted to estimate a final evaluation of said wheel suspension from said comparison,

wherein a plurality of combinations of system value ranges of said system elements are stored and each of said combinations correspond with a predetermined class of vehicles, wherein said processing unit being adapted to classify a tested vehicle by means of said computed system values of said system elements in said predetermined class of vehicles and being further adapted to compare said value of each of said evaluation variables with values of said evaluation variables applying for a corresponding class of vehicles.

said display unit being adapted to display said final evaluation.

10. Apparatus according to claim 3, wherein said casing is combined with each of said measuring plates into one construction unit.

4. Apparatus for testing a wheel suspension of a vehicle, comprising

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of a vehicle on said measuring plate, and

a processing unit for processing measured values provided by said first measuring means,

wherein said processing unit being adapted to correct said measured values of said first measuring means for a force caused by a moving mass of said measuring plate.

5. Apparatus according to claim 4, wherein a second measuring means is provided for measuring a selected one of a position, velocity and acceleration of said measuring plate, wherein said processing unit being adapted to determine said force caused by said mass of said measuring plate from measured values of said second measuring means and a predetermined mass of said measuring plate, wherein said force is subtracted vectorially from said measured values of said first measuring means in a correct phase.

6. Apparatus for testing a wheel suspension of a vehicle, comprising:

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle of said measuring plate,

a processing unit for processing measured values provided by said first measuring means, and

a display unit for displaying a measuring result,

wherein said processing unit being adapted to make a calibration of said first measuring means by moving said measuring plate in an unloaded situation and by comparing said measured value of said first measuring means caused by a mass of said measuring plate with a force value computed from a predetermined mass of said measuring plate, an amplitude of a movement and a frequency of said movement.

7. Apparatus for testing a wheel suspension of a vehicle, comprising

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle of said measuring plate,

a processing unit for processing measured values provided by said first measuring means,

a display unit for displaying a measuring result,

wherein a brake means is provided, said brake means being actuated by said processing unit, wherein said processing unit being adapted to stop said excitation mechanism by activating said brake means after passing a resonance frequency of said wheel suspension, whereafter said processing unit being further adapted to process said measured values provided by said first measuring means for measuring forces exerted by said wheel on said measuring plate after said excitation mechanism has been stopped.

8. Apparatus according to claim 7, wherein said processing unit being adapted to stop said excitation mechanism substantially at said resonance frequency of a body of said vehicle.

9. Apparatus for testing a wheel suspension of a vehicle, comprising

at least one measuring plate adapted to be moved by an excitation mechanism,

a first measuring means for each measuring plate for measuring vertical forces exerted by an air tire of said vehicle on said measuring plate,

a processing unit for processing measured values provided by said first measuring means, and

a display unit for displaying a measuring result,

wherein said display unit is mounted in a casing with a base, said casing being provided with two display means with equal function, one of said display means being adapted to enclose an acute angle, the other display means being adapted to enclose an obtuse angle with a driving direction of said vehicle,

wherein said casing being disposed beside said measuring plate of said apparatus.