## 3 Simulation and Analysis of the Sugarcane Leaf-Picking Process  
### Analysis of the Working Process of the Pick-up Mechanism  
The elastic teeth in the elastic teeth roller picking mechanism make up a complex composite of motion elements. While following the advance of the sugarcane leaf cutting and returning machine and the rotation of the roller plate, it oscillates regularly and repeatedly in relation to the roller plate. The rotation-position relationship of the roller plate corresponding to the posture change of the elastic teeth in the movement process is defined as the pick-up phase of the elastic teeth, which is expressed by the rotation angle of the roller plate. After observation, it is found that the roller plate rotates clockwise for one cycle, and each elastic tooth continuously completes a pick-up cycle of four stages: \"pick-up\", \"lift-up\", \"push-up\" and \"empty return\". The phase diagram of the picking mechanism is shown in Figure 5.  
(1) The pick-up stage (elastic tooth phase angle \(\alpha_{1}\)) imitates the situation in which people pick up sugarcane leaves with a plow. The elastic teeth are initially inserted between the ground and the sugarcane leaves at a certain inclination. The ends of the teeth then start to contact the sugarcane leaf, and the teeth gradually move to the horizontal position. Under the combined absolute speed of the roller plate rotation and the horizontal advancement of the returning machine, the end speed of the elastic teeth begins to rise gradually, so that the sugarcane leaf can be picked up and rotated clockwise along with the elastic teeth.  
(2) The lift-up stage (elastic tooth phase angle \(\alpha_{2}\)): At the beginning of the lift-up stage, the elastic teeth are in the same radial direction as the roller plate and in a horizontal state. As the roller plate rotates, the linear speed at the end of the elastic teeth changes from  
Figure 5: Phase diagram of the picking mechanism.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Contact Model** & **Keywords** & **Static Friction** & **Dynamic Friction Coefficient** \\ \hline Sugarcane leaf and elastic teeth & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.6 & 0.58 \\ Sugarcane leaf and ground & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Sugarcane leaf and guard plate & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Sugarcane leaf and door frame & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Sugarcane leaf and sugarcane leaf & AUCIMATIC\_SN & 0.1 & 0.05 \\  & CLE SURFACE & 0.1 & 0.05 \\ Roller plate and power shaft & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Roller plate and elastic teeth rod & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Crank linkage and roller wheel & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Cam plate and roller wheel & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ Cam plate and power shaft & AUTOMATIC\_SURFACE\_TO\_SURFACE & 0.1 & 0.05 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Contact settings.  
vertical upwards to rear upwards in order to lift and transport the sugarcane leaf above the guard plate.  
(3) Push-up stage (elastic tooth phase angle \(\alpha_{3}\)): At the beginning of the push-up phase, the teeth are basically in a plumb position, and the relative velocity direction is horizontal backwards, pushing the sugarcane leaf backwards.  
(4) Empty return stage (elastic tooth phase angle \(\alpha_{4}\)): At the beginning of the empty return stage, the elastic teeth have shrunk into the guard plate. With the continuous rotation of the roller plate, the elastic teeth that carry out relative movement will return to the initial position of the pick-up stage after finishing the pick-up, lift-up and push-up stages, so as to prepare for the next picking cycle. During this time, the elastic teeth are not in contact with the sugarcane leaf and the ground, but their angular acceleration of oscillation relative to the roller plate is high, in order to return to the original picking position as soon as possible at the start of the next picking phase.