Design and Compliance Control of a Robotic Gripper for Orange Harvesting

The existing manual orange harvesting needs to be automated to reduce high labor cost and minimize perishing of fresh fruit due to manual harvesting. In this paper, a preliminary design of a robotic gripper for orange harvesting and its compliance control is presented. The main focus is to have a low cost and lightweight design with a soft touch, actuated by a lead screw based mechanism. During grasping and detaching of fresh fruit, robotic gripper is in direct physical contact with the fruit. Thus, gripper need to behave like a complaint system to generate adequate force for picking of orange and avoid bruising of fruits and other parts of plant. To incorporate compliance control, integral sliding mode control is employed which emulate the behavior of an ideal mass-spring-damper system. The effectiveness of the dynamic model-free controller is validated through simulation.