# Monitoring Autonomous Mowers Operative Parameters on Low-Maintenance Warm-Season Turfgrass
## 2 Materials and Methods
### Experimental Field Trials  
From September to October 2021, 8 sample plots of 25 m\({}^{2}\) were identified within the larger area above mentioned. The plots were selected in order to ensure that turf characteristics were balanced among the selected areas. The main factor was the autonomous mower model with random trajectories (two levels: Husqvarna Automower(r) 450X and Husqvarna Automower(r) 535 AWD), while the second factor was the trampling level (four levels: working schedule set to work for 10, 30, 60, and 90 min). The working time of 10 min was  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Year**} & \multirow{2}{*}{**Month**} & \multicolumn{2}{c}{**Average Temperature (\({}^{\circ}\)C)**} & \multirow{2}{*}{**Precipitation (Days)**} & \multirow{2}{*}{**Humidity (\%)**} \\ \cline{3-3} \cline{5-6}  & & & 22 & & \\ \cline{3-3} \multirow{2}{*}{2021} & \multirow{2}{*}{September} & 27.4 & 16.9 & & \\ \cline{3-3} \cline{5-6}  & & 16.3 & & & \\ \cline{3-3} \cline{5-6}  & & 22 & 11.5 & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Weather conditions of the trial period.  
Figure 1: Workflow diagram of the research (Robot mower tracking data calculator® version 1.8.0.0.).  
chosen as the control trampling level since it represents the theoretical right time to manage every plot with random operating AM. In fact, according to the manufacturer operator's manual, the hourly work capacity of both autonomous mowers was significantly greater than the effective work areas available. These trampling levels were selected to simulate the continuous and repetitive mowing activity achieving an over-trampling activity on the turfgrass. The short trial duration of 26 days was chosen specifically to fulfil its main objective: to analyze the operational performances of two different autonomous mowers (AMs) and their associated trampling activity on a standard turfgrass preceding dormancy.  
The two autonomous mowers were set to work for a different amount of time in each area. A total of four trampling levels were calculated and set based on the hourly work capacity of the two autonomous mowers (Table 2). For simplicity, the four trampling levels for each autonomous mower were called Control, Low, Medium, and High level.  
The Control trampling level for the AM 450X was obtained by leaving the AM working for 7 min in the studied area, while for the AM 535, it was obtained by leaving the AM working for 10 min in the studied area. For simplicity, Control trampling levels for both autonomous mowers were set at 10 min. The Low trampling level was obtained by leaving both AMs working for 30 min; the Medium trampling level was obtained by leaving both AMs working for 60 min; the High trampling level was obtained by leaving both AMs working for 90 min. The robot mowers worked following random trajectories, with an average speed of 0.62 m s\({}^{-1}\) and a cutting disk revolving speed of 2300 rpm.  
The base stations were placed 10 m away from each other. The plots were delimited by a boundary wire that generated an electromagnetic field perceived by the autonomous mowers as the edge of the garden. The boundary wire delimiting the different plots was positioned and fixed to the surface with stakes to ensure 20 cm of a corridor between plots to prevent the robot from moving in the wrong area during the assessment. Before starting the trial, the studied areas were moved at 3.7 cm with a walk-behind battery mower to guarantee uniform starting conditions. Then, the 2 autonomous mowers were set to work 5 days per week with a height of cut of 3.5 cm.