Design, Building, and Testing of an RRP Harvesting Robot Using VR Simulations

A robotic harvester based on spherical RRP/2RP manipulator has been designed and simulated using Virtual Reality (VR) tools. The factors considered in this work include the reach, dexterity, load-bearing capacity, accuracy, and productivity. Based on the results of the simulation, a prototype was built and tested on real olive fruits. The robotic arm comprises three links, two rotary joints, and one prismatic joint, actuated by two revolute motors and one linear motor, respectively. As picking a single fruit in each stroke is not practical, a rake was installed at the end-effector to enable the harvester to pick up multiple fruits each time. The manipulator is controlled by a Raspberry Pi and guided by a stereovision camera to enable 3-D vision. In addition, Li batteries are used to power the manipulator in field operations. Once the fruits location is detected, an inverse kinematics algorithm is initiated, yielding the location in 3-points coordinates. Then the coordinates are commanded to the manipulator to move to the location and perform the picking operation. The results showed that the robot was successful in performing the required picking operations. For future work, it is recommended to build a larger prototype to achieve more effective harvesting of large trees.