## 3 Results
### Test Results  
#### 3.2.1 Rectangle-Shaped Field  
The geodetic coordinates of the rectangle-shaped field boundary points for the test were entered clockwise from the northwest corner. The lengths of the four-line segments of the outer boundary of the field are approximately 36 m, 104 m, 36 m, and 104 m clockwise from the first input point, respectively, and the area is approximately 3741 m\({}^{2}\). The result of generating the inner boundary of the field using the coordinates of the input external boundary vertices is shown in Figure 4a. The short- and long-line segments of the inner boundary were approximately 98 m and 30 m, respectively, and the inner boundary was generated considering the length of the robot, so that the robot could rotate in place. Figure 4b shows the generated MBR of the internal boundary used to generate candidate sets consisting of line segments within the MBR. The results of the generated working line segments in the inner-field boundary and the headland area are shown in Figure 5a and Figure 5b, respectively. The number of generated working line segments in the inner-field boundary is 23. The range of the lengths of the generated working line segments in the inner-field boundary is 97.6 m to 97.8 m, and the sum of the generated working line segments in the inner-field boundary is 2247.9 m.  
Figure 4: External and internal boundaries and MBR for the rectangle-shaped field: (**a**) External and internal boundaries; (**b**) internal boundaries and MBR for internal boundaries. Figure 3: Boundaries of the four types of fields used in the experiment (red lines) obtained from Google Earth: (**a**) rectangle-shaped field; (**b**) trapezoid-shaped field; (**c**) pentagon-shaped field; (**d**) hexagon-shaped field. A total of four working line segments in the headland area were generated along the field boundaries. The range of the lengths of the generated working line segments in the headland area is 27.8 m to 96.1 m, and the sum of the generated working line segments in the headland area is 247.4 m. The total area of the ridges created through the working line segments is 2994 m\({}^{2}\), so 80% of the field area is created as ridges. For autonomous ridge-forming in the inner field, the results of the generated waypoints are shown in Figure 5(a). Waypoints were generated sequentially along the working line segments of the inner field that are closest in distance, starting near the first outer-field boundary point. A total of 91 waypoints were generated for autonomous ridge-forming in the inner field, and depending on the waypoint type, 1 starting waypoint, 44 turning waypoints, 23 work-starting waypoints, and 23 work-ending waypoints were generated. The total length of the autonomous driving path consisting of waypoints is 5433.8 m.  
The waypoints for returning to near the first outer-field boundary point were generated as the shortest path starting from the last waypoint of the autonomous ridge-forming in the inner field to the vicinity of near the first outer-field boundary point, as shown in Figure 5(b). The total number of generated waypoints is four, including one starting waypoint, two turning waypoints, and one ending waypoint, and the total length is  
Figure 5: Working line segments for the rectangle-shaped field: (**a**) working line segments in the inner-field boundary; (**b**) working line segments in the headland area. Figure 6: Waypoints for the rectangle-shaped field: external boundaries (black lines), internal boundaries (magenta line), autonomous driving path (blue lines), start waypoint (triangle), straight or turning waypoint (plus), work-starting waypoint (circle), work-ending waypoint (diamond), ending waypoint (star); (**a**) waypoints for ridge-forming work in the inner-field boundary; (**b**) waypoints for returning to the starting point; (**c**) waypoints for ridge-forming work in the headland area.