Design and Experiment of a Novel Manipulator for Autonomous Harvesting Tomato Clusters

A cherry tomato picking robot manipulator was designed for greenhouse cherry tomato harvesting in bunches. The manipulator consists of an end-effector and its control system which adopts the “bottom-up” enveloping fruit harvesting method to complete the shearing and clamping of the fruit stems of the fruit bunches to realize the bunch picking operation of cherry tomatoes. The end-effector adopts a gearing - five-link mechanism, and the structural parameters are designed using the analytical method with length and envelope constraints. The structural parameters are optimized by analyzing the mechanical properties of fruit stalk shearing and the shearing and clamping motion process of the gear-five-link mechanism. The experimental results showed that the fruit envelope success rate of the end-effector of the string tomato picking robot was 92%, the picking success rate was 87%, the fruit damage rate was 7%, and the average picking time was 10.43s per string.