In-vehicle data logging system for fatigue analysis of drive shaft

Abstract

The work presents a cost-effective custom-made data logging system for in-vehicle use. Based on the required bandwidth and accuracy of the torque signal a real-time data acquisition system for long-term data logging of torque signal has been designed and implemented. The system is based on a computer running Windows CE 3.0 operating system. Filtered input signal is sample by over-sampling data acquisition system. Data reduction is achieved by decimation and data compression. Three data compression methods are compared: two methods based on zero-order and first-order predictors and a piecewise linear approximation method followed by run-length and Huffman coding. Several error bands have been investigated in the data compression methods. Test result show that a system with 1 GB flash card can store over 10000 hrs of drive shaft load history data allowing signal reconstruction with satisfactory accuracy.