# Design and Test of a Single-Row Harvesting and Cutting Integrated Handheld Garlic Harvester
## 2 Materials and Methods
### Analysis of Garlic Harvester Dynamics
#### 2.3.2. Clamping Mechanism Dynamics Analysis  
Through this research, we know that the height of mature garlic seedlings is 600 mm, the part clamped by the clamping point in the holding device is the white part of the garlic, and the height distance of garlic white from the head of the garlic is 100-150 mm, so the height of the clamping point of the clamping chain of the machine from the ground should be within this range. The height of the clamping point from the ground was 120 mm, the inclination angle \(\alpha\) between the main frame and the ground was 40\({}^{\circ}\), and the corresponding mechanical structure is shown in Figure 7.  
The height h of the end of the holding chain from the ground can be obtained as follows:  
\[h=H-(D+\frac{d}{2})\cdot\sin\alpha \tag{5}\]  
where:  
\(h\)--height of the end of the holding chain from the ground (mm).  
\(D\)--vertical distance between the sprocket and the sprocket axis (mm) can be easily derived as 60 mm from the installation position and the size of the frame.  
\(d\)--diameter of the small sprocket (mm); diameter of 60 mm when the standard part is selected.  
\(\alpha\)--angle of inclination of the frame to the ground (\({}^{\circ}\)).  
All parameters were substituted to derive the height of the clamping point from ground \(h\) = 62.5 mm.  
The power of the clamping chain is provided by the gasoline engine, which can realize the integrated control of clamping, transportation, cutting, and walking through the adjustment of the gearbox. The running speed of the clamping chain is controlled by the gearbox, and the linear speed of the transport chain is constrained by the running speed of the garlic harvester, the speed of the limit cutting knife, the size of the diameter of the transport chain sprocket, and other important parameters. A reasonable linear speed is the basis for the coordinated and stable operation of all mechanisms of the garlic harvester and the key to the realization of each function. The relevant design and calculations are as follows.  
Through the power provided by the gasoline engine and the adjustment of the gearbox and gear transmission, the running speed of the single-row harvesting and cutting integrated handheld garlic harvester was clarified to be \(v_{1}\) = 0.4 m/s, \(v_{2}\) = 0.8 m/s, and \(v_{3}\) = 1.2 m/s speed gears, respectively. After analysis and testing, the optimal running speed of the garlic harvester was measured as \(v_{2}\) = 0.8 m/s, and the planting spacing of garlic was derived from field investigation and research as D. By calculation, the time  
Figure 7: Mechanical sketch of clamping mechanism.  
interval between two clamps of the transport chain of the garlic harvester to the garlic can be calculated.  
\[t_{1}=\frac{d}{v_{2}}=\frac{0.15}{0.8}s=0.1875\;\mathrm{s} \tag{6}\]  
To ensure the good operation and cutting effect of the garlic seedling limit cutting mechanism, the spacing of garlic on the transport chain \(d_{1}>120\;\mathrm{mm}\) was used, and to ensure the quality of harvesting, the ideal linear speed of the transport chain with spacing \(d_{1}=140\;\mathrm{mm}\) was used:  
\[v_{1}=\frac{d_{1}}{t_{1}}=\frac{0.14}{0.1875}=0.747\;\mathrm{m/s} \tag{7}\]  
Before the garlic is transported to the clamping and transportation unit, it passes through the gathering device, which collects the fallen garlic and brings it together, ensuring that all garlic can enter the clamping mechanism. At the end of the clamping and transporting device, the sheared garlic heads were dropped into the collection box below, whereas the garlic seedlings were transported with the transport chain to the end of the garlic harvester and then dropped on both sides of the garlic row without affecting the movement of people.