Development of a 5DOF robotic arm (RAVebots-1) applied to heavy products harvesting

摘要

Abstract: Robotics can play a significant role to increase efficiency and lighten the farmer’s load. Despite challenges in the agricultural robotic designs, robots are capable of performing various tasks and changing themselves accordingly, based on specific conditions. To address modern problems in the agricultural field, an agricultural robot is one of the key technologies. Although agricultural robotic is still in the development stage, these particular robots have a bright future ahead. This paper proposes a new 5DOF articulated robotic arm design that would become a solution for heavy crop harvesting like pumpkin and cabbage. The main design process of the device was conceived using 6 stages of Shigley design process. All components were designed, assembled and analyzed by using Solidworks 2014 in compliance with JIS standards. The parts of the system that had dynamic nature were analyzed manually using standard mechanical formulas. Calculations of the workspace, required joint torque, and coordination of mass center position were developed using standard machine design methods. Denavit-Hartenberg method was used to calculate forward and reverse kinematics. To resolve the torque reduction, components were designed by different material and mass center and were compared together. Results showed that total torque in Joints number 1, 2, 3, 4 and 5 were 6.15, 257.35, 103.4, 20.2 and 0.1 N. m respectively with a rotational speed range of 15 ~ 60 rpm. Changes in the linkage material and servo motor location improved 29.7% ~ 47.7% and 29.7% ~68.9% of the total required torque for each joint. The maximum distance covered by the arm was 1640 mm from the J 2 and 1830 mm from the attachment point. According to the feedback received from a reverse kinematics equation algorithm, the fundamental operation of the robot arm had an optimal performance.