Design and Analysis of Double-Ring Robotic Coconut Tree Climber for Enhanced Performance

In the dynamic field of agricultural technology, the development of coconut tree climbers exemplifies significant progress in addressing the challenges of efficient and safe coconut harvesting. Designing an unmanned coconut tree climber robot is complex due to the unpredictable structures of the coconut tree trunk and crown. Key challenges include developing a climbing mechanism, ensuring smooth ascents and descents, managing payload stability, and designing an effective harvester for coconut bunches, all of which impact the robot's overall performance. This paper introduces a novel design featuring a double-ring structure for the climber robot, aimed at enhancing its performance. The study includes a comprehensive static analysis to determine the average range of torque values for the actuators. Dynamic and kinematic analyses are conducted to establish essential relationships that predict the robot's characteristics before testing. A four-degree-of-freedom manipulator is used as the harvester. The proposed methodology was tested on a coconut tree trunk in a lab setup and field conditions across 10 different coconut trees. Real-time data collected during these tests were validated against predictions made through simulations before experimentation. The analyses, including theoretical analysis, simulation outcomes, and experimental test setups, conclusively demonstrate that the proposed structure maintains consistent stability throughout the climbing process, even on trees with varying inclinations and trunk radii relative to height. The success rates of the double-ring setup consistently surpass those of the single-ring configuration, with success rates ranging from 80% to 100% for the single ring and 100% for the double-ring setup.