Design and analysis of a 4-PPPR parallel manipulator for strawberry harvesting in the ridge cultivation model

Abstract

Strawberries possess impressive nutritional and medicinal value, and the demand for them has been kept on increasing on the global market. For their harvest consumes a large portion of the whole production costs and causes health problems to the labors, researching and developing strawberry harvesting robots is becoming an emergency of meeting the economy requirement in the world. In consideration of the parallel mechanisms' advantages and the lack of their utilization in the field of strawberry harvest, this paper proposed a 4-PPPR manipulator to pick strawberries in the ridge culture. Based on the GF set theory, this manipulator was proved to have three translational motion DOF and one rotation DOF, which make it competent to conduct harvest task in the ridge cultivation model. Furthermore, analyses for inverse kinematics and velocity equation were also carried out in order to support further studies, such as controlling and optimizing of this manipulator.