## 2 Materials and Methods  
### Institutional Design and Operational Process  
The aim of this study is to mechanize the grafting of panicle and stock seedlings, pick seedlings from plug trays, transport seedlings, and obliquely cut seedlings, to improve the operational efficiency of the grafting process. The overall structure comprises a clamping and cutting arrangement device for Solanaceae scion and stock seedlings, combined with a UR5 robotic arm, programmable controller, air pressure supply component, plug-tray assembly, and cutting table assembly (Figure 1). The device design features are as follows:  
* Multiple-type grafting operation: Compared with clamping a single plant before leveling, by clamping multiple seedlings--that is, four or eight at a time--the operational efficiency of the grafting process can be improved. * Standardization of clamping and chamfering: the proposed device can align the seedlings, position them, and produce a consistent chamfering angle. * Plug-tray specifications: The proposed device complies with the plug-tray specifications used by seedling growers in Taiwan--that is, it caters to 104 grid plug trays (8 \(\times\) 13) in bulk. * Applicable to tomato seedlings and eggplant seedlings: The proposed device is not limited to the use of single crop seedlings, its operation being more flexible. The clamping and cutting arrangement device for the Solanaceae scion and stock seedlings can be divided into two parts--that is, the clamping structure and the chamfering structure. The gripping structure (Figure 2) can be equipped with different power sources. The claw head is designed to simulate the action of three fingers gripping objects and is designed in an array structure; [PERSON] et al. also have a similar clamping method [16]. Based on the number of claw heads, up to eight seedlings can be clamped \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Country** & **Model** & **Type** & **Operator** &
\begin{tabular}{c} **1 h Grafted** \\ **Seedlings** \\ \end{tabular} \\ \hline \multirow{3}{*}{Japan} & Robo-GRF & Semiautomatic & 1 & 400 \\  & Robo-GRF AUTO & Automatic & 1 & 800 \\  & ISO Graft 1100 & Semiautomatic & 2 & 1000 \\ The Netherlands & ISO Graft 1200 & Semiautomatic & 1 & 1050 \\ Italy & GR300 & Semiautomatic & 1 & 300 \\ Spain & EMP-300 & Semiautomatic & 1 & 390 \\ Korea & GR600C-S & Semiautomatic & 2 & 800 \\  & The soft-clip fruit-bearing & & & \\  & vegetable seedling grafting & & & \\ Taiwan & robotic system & & & \\  & Grafting auxiliary machinery & Auxiliary & 1 & 300 \\  & Conveyor type grafting & Auxiliary machinery & Auxiliary & 4 & 1058 \\  & Auxiliary machinery & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Models of tomato grafting machines developed by various countries. in a single operation. To simultaneously hold multiple seedlings, the claw head is designed into a \(\zeta\) -shaped structure, so that the seedlings are concentrated in the center of the \(\zeta\) -shape when clamping, the positioning effect being very helpful when oblique cutting of the seedlings is conducted. Additionally, the contact surfaces of the claws holding the seedlings are equipped with soft pads - designed with a hollow center - to maintain a steady grip of the seedlings and to avoid damaging them. Moreover, to increase the elastic space for clamping, seedlings with different stem diameters can be clamped at the same time. The chamfering structure (Figure 3) is equipped with a thin double-guide rod pneumatic cylinder (brand, MCGJ-12-12-10) and up to eight seedlings can be chamfered in a single operation. The grooves of each knife holder and anvil are designed to be inclined at 20\({}^{\circ}\), and the slanted seedlings are fixed at 20\({}^{\circ}\). Previous studies suggest that increasing the level angle could improve the graft survival rate - that is, a level angle of 10-30\({}^{\circ}\) could achieve a survival rate of more than 90%.