Data Acquisition System Design with Applications to Fatigue Analysis of an Automatic Transmission System

摘要

This paper presents a stand alone data acquisition system for in-vehicle use. It is designed in such a manner that the torque signals of an automatic transmission system shafts can be monitored over a long period of usage. The bandwidth and the required accuracy of the signal have been used in setting up the operational parameters of the data acquisition system. The filtered torque signals are over sampled to ensure the desired accuracy and a unity gain at a bandwidth of 20 Hz within which significant signal components are located. The acquired data are processed through data reduction and data compression. Three data compression methods are compared; two predictive methods, namely zero-order and first-order predictors and a piece-wise linear approximation method, followed by run-length coding. Test results presented show that 1 GB compact flash card can store over 8000 hours of drive shaft load history data and their reconstruction ensured the desired accuracy.