柑橘采摘软体末端执行器的设计与试验

Design and experiment of citrus harvesting software end-effector

为实现柑橘的无损采摘,本文设计了1款采摘软体末端执行器。基于Yeoh本构模型建立软体手指弯曲变形力学模型;借助有限元仿真进行中心组合设计试验,最终取最优组合参数为:气囊高度为7 mm、限制层厚度为3.5 mm、气室厚度为3 mm;通过MATLAB拟合ANSYS有限元仿真结果,进行了力学模型修正;制作软体手指进行弯曲试验,验证了力学模型与有限元仿真可靠性;通过ANSYS有限元仿真得到软体手指充气压强为0.035~0.07 MPa,软体机械手即满足刚度要求又不损伤柑橘。搭建试验平台,得出最大气压下最大挤压力为18.13 N,试验证明采摘软体末端执行器无损夹持柑橘成功率为96.67%,平均采摘1个柑橘需要耗时3.54 s。

In order to realize the nondestructive picking of citrus,a soft end effector was designed in this paper.A mechanical model of soft finger bending deformation was established based on Yeoh constitutive model.The center combination design test was carried out by finite element simulation.The optimal combination parameters were as follows:the height of the airbag was 7mm;the thickness of the limiting layer was 3.5mm and the thickness of the air chamber was 3mm.The mechanical model was modified by fitting ANSYS finite element simulation results with MATLAB.The mechanical model and finite element simulation were verified by bending test of soft finger.Through ANSYS finite element simulation,the inflatable pressure of soft finger was 0.035~0.07 mpa,and the soft manipulator not only met the stiffness requirements but also did not damage citrus.The experiment platform was set up,and the maximum squeeze pressure was 18.13 N under the maximum atmospheric pressure.The experiment proved that the success rate of nondestructive clamping of citrus by the soft end-effencer was 96.67%,and the average time of picking a citrus was 3.54 s.