Mechanical design of a fruit picking manipulator: improvement of dynamic behavior

Application of robotics to agriculture involves specific design of manipulators to account for the need of light structures working at high speeds and acceleration, while preserving the environment against damage. All these requirements, mainly the speed and acceleration, define the choice of manipulator´s structure and optimize the mechanical design for the manipulator dynamics. This paper presents the specific design of a manipulator for harvesting fresh fruit (oranges). First, we discuss the optimum manipulator structure taking into account all the necessary requirements. We then use, in order to improve the resulting dynamics, the nonlinear performance index defined in a our previous work, to reflect the nonlinear effects on the actuators due to internal parameters of the structure, and extend it to take into account the changing payload for an improved design