Optimization of occupational whole body vibration exposure for rotavation operation

Abstract

The study focused to investigate the relative importance of forward speed, pulling force and tilling depth on tractor ride comfort in terms of overall vibration total value (OVTV). Taguchi’s L27 orthogonal array used to formulate a systematic design of experiments. It provided twenty-seven (27) experiments with five (5) replications for each set to get an average of root mean square (RMS) weighted acceleration value (aw). Point vibration total value (PVTV) was calculated at three different locations (i.e. tractor platform, seat-pan and seat backrest) in order to obtain OVTV. The magnitude of overall vibration total value (0.637–0.843 m/s2) represents the ride little to fairly uncomfortable as per ISO 2631-1 (1997). The fast fourier transform (FFT) analysis resulted dominant frequencies around 10 Hz and 12 Hz, which is observed to be very sensitive frequencies for human body due to existence of natural frequencies of various body parts. The optimum values of forward speed, pulling force and tilling depth are 1.3 m/s, 6 kN, and 0.16 m to obtain reduced OVTV.