Abstract:To achieve the ripe-picking and green-leaving harvesting of winter jujube, and considering the planting environment of facility jujube orchards, an adjustable-amplitude, variable-frequency test device with information sensing capabilities was designed to find the vibration harvesting parameters of winter jujube.The main factors affecting the shedding of jujube fruits under forced vibration were explored to obtain the maximum shedding rate of ripe fruits and the minimum shedding rate of green fruits.A fruit pendulum dynamics model was constructed to solve the model and determine that the main factors affecting fruit shedding were vibration frequency, vibration amplitude and vibration time.Then a shedding simulation test was carried out on a display push-pull meter to determine the shedding order of ripe fruits, green fruits and fruit stalks, which proved the feasibility of picking ripe fruits and leaving green ones.Finally, the mathematical model between the shedding rate and the harvesting parameters of the harvester was established.The harvesting parameters were optimized with the ripe fruit shedding rate and green fruit shedding rate as indicators, and the optimal parameter combination for picking ripe winter jujube and leaving green jujube was obtained as follows:the shedding rate of ripe fruit was 70.08%, and the shedding rate of green fruit was 11.97% when the vibration frequency was 12.66 Hz, the vibration amplitude was 15.02 mm, and the vibration time was 3.98 s.The optimization results were verified by field tests, and the test results were close to the optimized values.