柑橘采摘机器人结构设计及运动学算法

Structural design and kinematics algorithm research for orange harvesting robot

针对柑橘树冠较高,果梗木质化程度高、短且坚硬的特点,设计了新颖的柑橘采摘机器人手臂和末端执行器.根据其工作特征给出了能够提高运算速度的约束条件,并运用D-H法建立了机器人坐标变换矩阵,分别给出了机器人运动学正解和逆解.仿真和试验结果表明了机器人结构设计及运动学算法的合理性、有效性.机器人臂展1 048 mm、工作空间1.88 m3,末端执行器结构紧凑、功率低、剪切效率高且不会损伤柑橘,切割果梗3和6 mm的柑橘平均时间分别为3和9 s.该机器人高度高、臂展长、工作空间大,能够满足大棚种植模式下的自动化采摘,同时适应于苹果、梨、桃及西红柿等果蔬的自动化采摘.

With respect to the characteristics of the orange tree which often has high crowns,short and hard stems with high degree of lignifications,this paper presents a design and implementation of a novel orange harvesting robot which is composed of an arm and an end-effector.Based on the working characteristics of the robot,the constraint conditions which can speed up the computation is given.Then the robot coordinate transformation matrix is derived by the D-H method.Besides,the kinematics and inverse kinematics of robot are provided.Both the simulation and experimental results demonstrate the rationality and effectiveness of the structural design as well as the kinematics analysis of the robot.The wingspan of the robot is 1048 mm,and the work space is 1.88 m3.The end-effector has a compact structure with low power consumption and high efficiency,which will not ruin the oranges.It takes about 3s and 9s to cut the oranges with 3mm and 6mm stems,respectively.The designed robot is tall,and has long arm span,therefore,its work space is large enough for harvesting the corps automatically in the greenhouse,as well as for the fruits and vegetables,e.g.,the apple,the pear,the peach,the tomato and etc.