Design a 4DOFs Delta Parallel Robot for Chili Destemming

Nowadays, chili destemming poses a technical challenge in the chili processing industry, so the research on chili destemming robot holds a significant value. This paper presents the design of the mechanical structure, control system, and visual positioning algorithm of a chili destemming machine. Firstly, a chili destemming machine featuring a (3T1R) Delta parallel robot and an end-effector destemming device is designed. Subsequently, the robot's kinematics and dynamics are analyzed, and a nonlinear-model-predictive-control (NMPC) algorithm is proposed to control the robot system and verify the system's rapid dynamic response characteristics. Finally, a chili stem cutting and positioning algorithm is devised to determine spatial cutting points and directions based on the training outcomes of the Yolact instance segmentation model, and its high accuracy is demonstrated.