# Design and Testing of a New Bionic Corn-Ear-Picking Test Device
## 4 Performance Tests with the Ear-Picking Test Table
### Test Results  
The results of harvesting 360 corn plants from nine groups of experiments showed that the newly developed bionic corn test bench could achieve a high rate of ear picking. No grain damage was caused to the picked corn ears, so it was not recorded in the results analysis table. Additionally, the ear-picking test could be completed for corn plants with different growth directions and scion heights. This indicated the reasonable design of the test device, although additional field trials are recommended. Finally, the integrity of the corn straw could be ensured with less damage and breakage occurring after harvesting. This indicated that the design requirements for straw recovery could be satisfied by the test device. The ear-picking rates of each group in the tests are shown in Table 4.  
From the range analysis results, the picking rate was found to be affected most significantly by the corn-feeding speed, which was followed by the snapping roller speed. At the same time, it can also be impacted, to some degree, by the angle between the snapping rollers and the clamping conveyor, but these had a small effect compared with the first two test factors. The ear-picking rate can be improved by accelerating the feeding speed and snapping roller speed. However, when the feeding speed is too fast, it can easily cause a large downward bending effect of the snapping rollers on the ears of corn and an insufficient clamping force on the corn straw. As a result, the straw falls from the clamping device during the snapping process, which causes the entire plant to fall, thus ending the snapping process. Therefore, the range analysis was carried out based on these experimental phenomena. Obviously, the optimal factors for improving corn ear picking can be combined with a snapping roller speed of 780 r/min, a corn-feeding speed of 1.5 m/s, and an angle between the snapping roller and clamping conveyor of 40\({}^{\circ}\). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Test No.**} & \multicolumn{4}{c}{**Factors**} \\ \cline{2-5}  & **A (r/min)** & **B (m/s)** & **C (\({}^{\circ}\))** & **y\({}_{1}\) (\%)** \\ \hline
1 & (1)9 & (1)1.0 & (1)30 & 80.0 \\
2 & (1)9 & (2)1.5 & (2)40 & 92.5 \\
3 & (1)9 & (3)2.0 & (3)50 & 87.5 \\
4 & (2)11 & (1)1.0 & (2)40 & 77.5 \\
5 & (2)11 & (2)1.5 & (3)50 & 85.0 \\
6 & (2)11 & (3)2.0 & (1)30 & 85.0 \\
7 & (3)13 & (1)1.0 & (3)50 & 85.0 \\
8 & (3)13 & (2)1.5 & (1)30 & 97.5 \\
9 & (3)13 & (3)2.0 & (2)40 & 95 \\ \hline \(y_{11}\) & 260.0 & 242.5 & 262.5 & \\ \(y_{12}\) & 247.5 & 275.0 & 265.0 & \\ \(y_{13}\) & 280.0 & 267.5 & 257.5 & \\ \(\overline{y}_{11}\) & 86.67 & 80.83 & 87.50 & \\ \(\overline{y}_{12}\) & 82.50 & 91.67 & 88.33 & \\ \(\overline{y}_{13}\) & 92.50 & 89.17 & 85.83 & \\ R\({}_{j}\) & 10.00 & 10.84 & 2.50 & \\ Optimized level & A\({}_{3}\) & B\({}_{2}\) & C\({}_{2}\) & \\ \hline Primary and secondary factors & & B, A, C & & \\ Optimal combination & & A\({}_{3}\) B\({}_{2}\) C\({}_{2}\) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of range analysis. Because the functional relationship between the ear-picking rate and the influencing factors needs to be further investigated, a fitting equation was conducted using the test results. The fitting equation was obtained as follows:  
\[\hat{y}=222.98-38.43A+1.77A^{2}+81.45B-26.67B^{2}+0.62 AB \tag{6}\]  
Additionally, the variance analysis revealed the main influencing factors of the ear-picking rate y and the rotational speed of the snapping roller A, as well as the function between the corn feed speed B and the angle C between the snapping rollers and the holding device. To be specific, in the calculation process, the ear-picking rate was influenced less by C than it was the other two factors within the angle range in the ear-picking test, therefore, it can be ignored.