# Research on Seeding Performance of Self-Propelled Industrial Hemp Seeder
## 4 Test and Verification of Seed Metering Device
### Multi-Factor Test  
4.5.1. Test Results and Regression Model Establishment  
Combined with the results of single-factor research, the multi-factor test was carried out with the rotation speed of the metering wheel 80-100 r/min, the diameter of hole 10-12 mm, and the depth of hole 5.5-7.5 mm as the horizontal range to study further the influence of various factors on the working performance of seed metering devices. Table 2 shows the horizontal coding table of test factors. The multivariate nonlinear regression models of the variation coefficient \(Y_{1}\) of seeding uniformity and the consistency coefficient \(Y_{2}\) of each row with respect to the rotational speed \(x_{1}\) of the metering wheel, the diameter \(x_{2}\) of the profiled hole, and the depth \(x_{3}\) of the profiled hole were established using Design-Expert 11.0 software. The models and coefficients are tested. Table 3 shows the test scheme and results. (1) The regression equation of variation coefficient \(Y_{1}\) of seeding uniformity is:  
\[ \begin{split} Y_{1}=3.63+0.20x_{1}+0.18x_{2}-0.25x_{3}-0.37x_{1} x_{2}+0.34x_{1}x_{3}\\ +0.26x_{2}x_{3}+1.62x_{1}^{2}+0.70x_{2}^{2}+1.13x_{3}^{2}\end{split}  \tag{23}\] \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Coding**} & \multicolumn{3}{c}{**Factor**} \\ \cline{2-5}  & **Speed of Metering** & **Hole Diameter** & **Hole Depth** \\  & **wheel** & **x\({}_{2}\)/mm** & **x\({}_{3}\)/mm** \\ \hline \(-1\) & 80.0 & 10.0 & 5.5 \\ \(0\) & 90.0 & 11.0 & 6.5 \\ \(1\) & 100.0 & 12.0 & 7.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Coding with factors and levels. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Experimental**} & \multicolumn{3}{c}{**Experimental Factor**} & \multicolumn{3}{c}{**Experimental Index**} \\ \cline{2-5}  & **Speed of Metering** & **Hole Diameter** & **Hole Depth** & **Variation Coefficient** & **Coefficient of Variation for Consistency** \\  & **wheel** & **x\({}_{2}\)** & **x\({}_{3}\)** & **of Seeding Uniformity** & **of Seed Quantity in Each Row** \\  & **x\({}_{1}\)** & **x\({}_{1}\)** & **0** & **0** & **0** \\ \hline \(1\) & \(-1\) & 0 & 1 & 5.78 & 2.03 \\ \(2\) & 0 & \(-1\) & \(-1\) & 5.73 & 1.22 \\ \(3\) & 1 & 0 & \(-1\) & 6.12 & 1.14 \\ \(4\) & \(-1\) & \(-1\) & 0 & 5.11 & 2.09 \\ \(5\) & 0 & 0 & 0 & 3.45 & 0.69 \\ \(6\) & 0 & 0 & 0 & 3.64 & 0.81 \\ \(7\) & \(-1\) & 0 & \(-1\) & 6.13 & 1.29 \\ \(8\) & 1 & \(-1\) & 0 & 6.43 & 0.89 \\ \(9\) & 1 & 0 & 1 & 6.55 & 1.06 \\ \(10\) & 0 & 0 & 0 & 3.78 & 0.76 \\ \(11\) & 0 & 1 & 1 & 5.67 & 1.67 \\ \(12\) & \(-1\) & 1 & 0 & 6.22 & 1.51 \\ \(13\) & 0 & 0 & 0 & 3.61 & 0.81 \\ \(14\) & 0 & 1 & \(-1\) & 5.59 & 1.05 \\ \(15\) & 0 & 0 & 0 & 3.69 & 0.89 \\ \(16\) & 1 & 1 & 0 & 6.07 & 1.73 \\ \(17\) & 0 & \(-1\) & 1 & 4.82 & 1.19 \\ \hline \hline \end{tabular} Note: \(x_{1}\) and \(x_{2}\), and \(x_{3}\) indicated the levels value of Speed of metering wheel, Hole diameter, and Hole depth, respectively. The same is below.  
\end{table} 
Table 3: Protocols and results. Table 4 was the result of the variance analysis. The regression model of variation coefficient of row uniformity showed that the model was extremely significant (\(p<0.01\)) and the model was effective (\(p>0.05\)). determination coefficient \(R^{2}=0.991\); the calibration determination coefficient was 0.979, both close to 1, and CV = 3.12%, accuracy Adeq precious = 82.66, indicating that the fitting equation has high reliability. Among them, the rotational speed of the metering wheel and the depth of the hole have a very significant indigenous effect on the equation. The diameter of the hole has a considerably indigenous effect on the equation. The influence of various factors on the variation coefficient of seeding uniformity is in the order of the rotational speed of the metering wheel \(x_{1}>\) the depth of the hole \(x_{3}>\) the diameter of the hole \(x_{2}\).