Abstract
The good performance of olive mechanical harvesting by shaking depends on the suitable values of limb vibrator operating parameters (frequency and amplitude). Mathematical models of a single degree of freedom (S.D.F.M) and two degrees of freedom (T.D.F.M) were used to estimate the natural frequency (F-N) of olive fruit stem system. The results from these models indicated that the F-N values were 33.9, 31.9, and 28.0 Hz for the full mature stage, half-ripe olive, and full-ripe olive respectively. Branch vibrator was operated at three levels of frequency 25, 30 and 35 Hz and 3 levels of amplitude 25, 30 and 35 mm at a vibration time of 10 s. Measurements covered the fruit removal percentage (FRP) and degree of full-ripe fruit selectivity (DS). The results showed that the maximum FRP value, 90.6%, was achieved at a frequency of 35 Hz and amplitude of 25 mm while the maximum DS value, 78.58%, was obtained at 25 Hz frequency and 25 mm amplitude.