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No contact balancing and diagnostics system for vehicles EEJA - Schenck South Africa

  • Vibration measurement at the vehicle
  • No contact measurement method using laser technology
  • Vibro-acoustic diagnostics
  • Evaluation of the unbalance of the drive train
  • Evaluation of the unbalance calculation
  • Possible to retrofit into roll test beds

Measuring principle design

The measurement uses the principle of non-contact vibration recording, using a laser vibrometer. Additionally, a speed or angle measurement is carried out by scanning a reference mark on a rotating part, e.g. the cardan shaft. Contactless measurement by laser allows vibrations to be recorded in parallel to other test procedures without any prior adjustment of the measurement sensors on the vehicle. The laser measurement head is mounted on an X-Y table on the rolling test bed, allowing different measurement positions to be accessed. By measuring the vehicle position, the measuring head follows the sideways movements of the vehicle. The connection to the rolling test bed controller enables the integration of the measurement procedure.

Range of application

The system is conceived for vibration measurement in completed vehicles during the EOL tests in the rolling test bed. The aim is to identify vibrations that ate caused through unbalances and errors in assembly. Integration into the rolling test bed is typically done in the area between the rollers for either the front or the rear axel. This allows you to achieve measurement points on the drive train in the are of the rear axel or the gearbox. Both a complete frequency analysis of the vibration signal and the unbalance of the drive train for example, can be determined through the speed-related measurement data recording and evaluation, which is usually done using the speed of a drive shaft. The system determines the required compensation for the unbalance, which can be achieved using a wide range of methods, e.g. the application of weights to the flange between the cardan shaft and the differential.
Technical data
Technical data at a glance  EEJA 
Equipment under test  Personal-vehicle on chassis dynamometer test bench 
Method of test  Measurement of vibrations and unbalance 
Unbalance correction  Mainly attaching of weights in the flange, between cardan shaft and differencial-drive