Simulation Study And Analysis Of Non-Destructive Picking Manipulator For Elevated Strawberries

In recent years,China’s research and development of strawberry harvesting robots has made continuous progress,and the number of strawberry harvesting robot patents has increased,which reflects people’s growing interest in agricultural automation.With the continuous advancement of technology and the maturity of automation technology,automated picking will become the mainstream trend in the strawberry farming industry.Based on this,this study designed the end effector and robotic arm of strawberry picking according to the growth status and physical and mechanical characteristics of elevated strawberries,and it can be seen from static analysis that in order to ensure the lightness of the end effector,the precision of picking operations and reduce the damage to strawberry fruits,aluminum alloy materials were selected as the prototype production materials of the fruit stem clamp of the actuator,ABS materials were selected as the fruit clip skeleton production materials,and silicone materials were used as the fruit contact surface production materials.And the drive control device with the end effector can achieve stable and non-destructive grasping of strawberry fruit,and the picking manipulator is simulated by ROS.The specific research content is as follows:(1)Taking Taian Rushan strawberry and Rongcheng strawberry under elevated cultivation as the objects,the characteristics were explored,and the physical parameters such as the shape,diameter,and height of the strawberry were described in detail.At the same time,the mechanical properties of the strawberry,such as the compressive properties of the strawberry pulp,and the shear properties of the fruit stem,were experimentally studied.(2)Starting from the physical and mechanical properties of strawberries and the needs of picking operations,a robotic end effector is designed for non-destructive picking of strawberries.3D modeling with UG software and static analysis of grippers and strawberries with ANSYS Workbench to verify the design of the end effector.(3)Based on the elevated strawberry picking environment and the existing mechanical arm structure design,the elevated strawberry picking mechanical arm is designed,and the D-H method is used to establish the mechanical arm coordinate system,as well as related parameters to describe the simplified mechanical arm.By calculating the motion of the robot arm,the forward and inverse kinematics are solved,the kinematics model is established,and its correctness is verified.(4)Convert the 3D model of the robot arm into a URDF file,and verify the conversion results;Configure the dynamics parameter file with the help of Setup Assistant and use Moveit!Collision detection is performed on the structure of the robot,and control algorithms are selected to plan the path of the designed harvesting robot,achieving the establishment of a simulation environment for the robot model in ROS.(5)In order to verify the feasibility and effectiveness of the designed manipulator,experimental tests were conducted,and the manipulator was applied to actual strawberry picking scenarios.The stability and reliability of the manipulator were verified.The experimental results were analyzed to determine the factors that affect the success rate of picking and the next research direction of the picking manipulator.This study proposes a design scheme for a non-destructive harvesting manipulator for elevated strawberries,and passes through physical and mechanical characteristics research,end effector design,robot arm kinematics modeling,simulation testing,and experimental verification.In the future,the design scheme can be further optimized to improve the harvesting efficiency and stability of the manipulator to meet the needs of agricultural production automation.