Collision Injury Assessment of Mechanical Harvesting Cerasus humilis Fruit Based on Deformation Energy

In order to evaluate degree of damage caused by collision between Cerasus humilis and equipment.Relationship equation of fruit deformation and deformation energy was established to evaluate degree of fruit damage.The quasi-static compression test showed that deformation energy was less than 28.56×10-3 J，and the fruit was slightly damaged.When the deformation energy was（28.56~195.57）×10-3 J，the fruit produces different degrees of moderate damage，severe damage and rupture damage.The drop impact test of Cerasus humilis fruit showed that bounce height decreases as the mass of fruit increases（r2=0.880 7）.As the falling height increased，the rebound height increased in accordance with the cubic curve（r2=0.825 5）.The deformation energy increased linearly（r2≥0.994 2），and the maximum was 43.9×10-3 J.Critical height of equivalent damage was 2.97 m.Mechanical harvesting can meet requirements of Cerasus humilis fruit picking.