为进一步提高果品振动采收效率,降低振动损伤,针对振动式果品采收机构的工作方式,提出了理想果树激振形式假设,并通过ANSYS软件仿真研究不同形式位移载荷对果树模型的影响。根据仿真结果,设计了基于外旋轮线轨迹的果品振动采收机构,分析了该机构的结构特点和工作原理,并建立其运动学模型,推导了机构振幅和加速度方程。在满足激振振幅和加速度的前提下,采用"参数导引"优化方法对外旋轮线机构进行尺寸优化。根据仿真结果与理论分析,加工试验样机,利用高速摄影系统捕捉样机的实际运动轨迹,并与理论轨迹、虚拟仿真轨迹对比,从而验证了外旋轮线机构设计的准确性。进行室内活立木动力学响应试验,并统计各测试点的最大合成加速度平均值和标准差,由此验证了外旋轮线机构可实现对果树的有效激振。
To further improve the efficiency of vibratory harvesting on tree fruit and reduce the mechanical damage on tree body,a hypothesis about ideal fruit tree excitation pattern was put forward based on the working principle of vibratory harvesting mechanism. The influence of different kinds of displacement patterns on vibratory fruit harvesting was simulated based on finite element software( ANSYS). According to the simulation results,a vibratory fruit harvesting mechanism was designed based on planetary gear train to generate epitrochoid trajectory. Then,its characteristics and working principle were analyzed and its kinematics model was established to derive the equations of vibratory displacement and acceleration amplitude. By meeting the requirement of displacement and acceleration amplitude,main parameters of the epitrochoid mechanism were optimized based on the parameter-guided optimization algorithm. A prototype of vibratory harvesting mechanism for fruit tree was manufactured and its trajectory was recorded by high-speed photography system. Trajectories of experiment,theoretical analysis and virtual simulation were consistent,which verified the design of this harvesting mechanism. A dynamic response test of one fruit tree sample was carried out in lab. Statistics results on the mean value and standard deviation of the maximum synthesized acceleration of the test points on the tree sample confirmed that the epitrochoid mechanism could stimulated the fruit tree effectively.