Whole Body Vibration Analysis of Tractor Operators Using Power Spectral Density

Tractor driving is an occupation exposed to prolonged sitting, twisted postures, Whole Body Vibration (WBV) and mechanical shock which are considered as low back pain risk factors. As agricultural tractor drivers are exposed to the periodic, random and transient mechanical vibrations which can reduce driver comfort, activities and health and according to provisions of ISO 2631-1, hence in this research effectiveness of WBV on driver comfort was investigated. The comfort of ITM 399 tractor operator, exposed to vibration during plowing, disking, hay baling and trailer transportation operations, was assessed. In order to analysis the amount of transmitted vibration energy to operator’s body correctly, Power Spectral Density (PSD) of WBV in all three directions (vertical, horizontal and axial) were considered. This type of calculations helped to determine maximum amount of energy and its frequency that has most effect on operator’s comfort. According to the result, total weighted acceleration had the maximum value for disking, hay baling, trailer transportation and plowing operation, respectively. It was concluded that in the three directions and at different operations, except for trailer transportation, maximum amplitude of WBV energy which is transmitted to operator’s body through driver’s seat takes place at low frequencies (under 5 Hz). KeywordsWhole Body Vibration; Tractor Operator; Power Spectral Density