摘要
提出了通过改进采摘机器人的末端执行器来实现未知柑橘果柄空间方位的柑橘采摘,以提高采摘机器人的采摘能力。对柑橘果柄生长情况进行了调研,定义了果柄倾角并进行了统计,对果柄极限位置的剪切要求进行了分析并得出了末端执行器的设计要求。根据蛇的咬合动作和蛇嘴骨骼的特殊结构,通过仿照蛇嘴结构设计咬合式末端执行器能够满足设计要求。对蛇头骨骼结构进行了简化,提出了两种设计思路,并据此分别设计了两种机构的初步模型,经过运动学分析确定了较优方案,并对初步模型进行了优化,确定了末端执行器的三维模型。根据三维模型建立了末端执行器的运动学模型,并进行了运动学分析和仿真,保证了机构设计合理。制造了咬合式末端执行器样机并通过课题组自行研制的柑橘采摘机器人进行了实验室环境和自然环境的实验验证。实验结果表明,在实验室环境下,果柄倾角为0°、气压为0.6 MPa、果柄直径不超过4.0 mm条件下的切断成功率不小于95%,不同果柄倾角的总体切断成功率为97.5%;在室外环境下,收获柑橘的总成功率为87.5%,基本实现了未知果柄空间方位下对柑橘的采摘。
Aiming to improve the picking ability of the harvesting robot,a bite-model end-effector for citrus was designed.The design requirements of the end-effector were obtained by first investigation of the growth of citrus stem,the inclination of the stem and doing statistics was defined,and the shearing requirements of the stem extreme position was lastly analyzed.That the design of the bite-model end-effector can meet the design requirements by simulating the snake mouth structure which followed the snake s biting action and the special structure of the snake s mouth bones.Two design ideas were proposed by simplifying the structure of the snakehead skeleton.Based on this,the initial model of the two kinds of mechanism was designed respectively.After the preliminary kinematics analysis,the optimal scheme was determined and the initial model was optimized,and the three-dimensional model of the end-effector was determined.According to the three-dimensional model,the kinematics model of the end-effector was established,and the kinematics analysis and simulation were carried out to ensure the reasonable design of the mechanism.A bite-model end-effector prototype was manufactured,and then it was verified by the citrus harvesting robot developed by the research group in laboratory and outdoor environment.In laboratory environment,the experimental results showed that the cutting success rate was not less than 95%under the condition that the air pressure was 0.6 MPa,the inclination of the stem was 0°,the stem diameter was no more than 4.0 mm,and the overall cutting success rate for different stem inclinations was 97.5%.The total success rate of harvesting citrus in the outdoor environment was 87.5%.
作者
王毅
许洪斌
张茂
马冀桐
刘波
何宇
WANG Yi;XU Hongbin;ZHANG Mao;MA Jitong;LIU Bo;HE Yu(College of Mechanical Engineering,Chongqing University,Chongqing 400044,China;College of Mechanical Engineering,Chongqing University of Technology,Chongqing 400054,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2018年第10期54-64,共11页
Transactions of the Chinese Society for Agricultural Machinery
基金
重庆市重点产业共性关键技术创新专项(cstc2015zdcy-ztzx70003)
重庆市基础研究与前沿探索(一般)项目(cstc2018jcyjAX0071)
重庆市基础科学与前沿技术研究一般项目(cstc2016jcyjA0444)