## 3 Results  
### Single-Factor Test Results and Analysis  
According to the simulation results of the single-factor test of blade rack type, the line graph of the effect of blade rack type on the debris removal rate is drawn. From the image, the debris removal rate of the triangular rack type is the highest, the debris removal rate of the rectangular rack type is slightly lower than the triangular rack type blade, and the debris removal rate of the oblique rack type blade is the lowest. During the simulation, it was analyzed that the teeth width of the rectangular rack is slightly more expansive, and the gap between the teeth was slightly narrower, which made some soil particles stick to the blade and caused the separation to be uncompleted. In contrast, the teeth of the oblique rack-type blade were tilted and distributed, which made some soil not pass through the gap between the teeth. Compared with the other two blades, the contact area between soil particles and the oblique rack-type blade was more extensive and easier to stick to. Hence, the debris removal rate was the lowest. The single-factor experimental results of blade type are shown in Figure 10.  
Based on the simulation results of the single-factor test of the tilt angle, the line graphs of the tilt angle and the debris removal rate, the percentage of bond breakage between potato soil particles, and the percentage of bond breakage between soil particles are plotted, as shown in Figure 11. It was found that the debris removal rate and the percentage of bond breakage between soil particles decreased with the increase in the tilt angle. When the tilt angle increases from 30\({}^{\circ}\) to 60\({}^{\circ}\), the debris removal rate drops from 98.1% to 84.4% (a fluctuation of 13.7%). The percentage of bond breakage between soil particles decreases from 99.3% to 86.7%, and the percentage of bond breakage between potato soil particles remains above 95. According to simulation process analysis, this is because as the tilt angle increases, some crushed soil particles stick to the blade and then move to the end of the lifting chain, resulting in a higher soil content and a lower percentage of debris removal rate. According to the simulation results of the single-factor test of blade speed, the line graphs of blade speed and debris removal rate, the percentage of bond breakage between potato soil particles, and the percentage of bond breakage between soil particles are plotted, as shown in Figure 12. The debris removal rate decreases with the increase in blade speed. When the blade speed increases from 0.4 m/s to 0.6 m/s, the debris removal rate drops from 98.4% to 89.3% (a fluctuation of 9.1%). The percentage of bond breakage between soil particles increases briefly and then decreases gradually. The percentage of bond breakage between potato soil particles decreases from 100% to 92.3%, which is because when the blade speed increases, the crushing and separation time on potato soil agglomerates decrease, resulting in insufficient soil fragmentation. Figure 10: Single-factor test diagram of blade rack type. According to the simulation results of the single-factor test of the lift chain bar line speed, the line graphs of the lift chain rotation speed and the debris removal rate, the percentage of bond breakage between potato soil particles, and the percentage of bond breakage between soil particles are plotted, as shown in Figure 13. The debris removal rate decreases with the increase in the linear speed of the lift chain bar. When the speed increases from 0.151 m/s to 0.453 m/s, the debris removal rate decreases from 95.6% to 92.8% (a fluctuation of 2.8%). The percentage of bond breakage between soil particles always fluctuates between 97 and 98. The percentage of bond breakage between potato soil particles decreases from 98.9 to 96, which is because when the speed of the lift chain bar increases, some soil particles will be broken and moved to the end of the lift chain before they drop from the bar gap. Figure 11: Single-factor test diagram of the tilt angle.