Measurement of Hand-Arm Vibration Syndrome of an Agricultural Tractor Steering Wheel using Machine Vision System

Abstract

The structure of an agricultural tractor is a structure without a suspension system to limit the vibrations generated by its engine. It exposed the entire body of an agricultural tractor operator to vibration. Thus, the body of the driver, constantly exposed to the vibration, becomes fatigued. This fatigue becomes a factor in the driver's inattention. The driver’s body has transmitted to vibration through the tractor's seat, accelerator pedal, brake pedal, and steering wheel. Quantifying seat, accelerator pedal, brake pedal, and steering wheel vibrations is one of the most important factors in determining the cause of vibration and correcting it. The ISO 5349 standard lays down a guideline for the measurement and assessment of vibrations transmitted by the human hand. To meet the ISO 5349 standard, assess human exposure to hand-transmitted vibration and meet the human subjective comfort level. It must keep the vibration within a specified range. This study attempts to measure steering wheel vibrations through a new machine vision system using up-sampled cross correlation and a Discrete Finite Transform algorithm. In this study, it was impossible to calculate vibration in three axes from the video images recorded by the camera. According to ISO 5349-2, the vibration obtained on two axes multiplied by 1 to 1.7 to calculate the equivalent measurement for the vibration on the third axis.
The results show that when the vibration is high; the errors are less and when the vibration is low, near zero, the errors range from 30 % to 50 %. But this study suggests that very low-level vibrations are unnecessary for vibration analysis.
This study is not suitable for Nano-vibration measurement methods that measure fine vibrations.