Assessing the efficiency of three different mowing patterns for an autonomous mower in a golf course

The introduction of the systematic parallel-line mowing system has revolutionized the use of autonomous robots for mowing sports turfs, making these machines much more efficient. RTK-GNSS technology allows autonomous robots to follow specific mowing patterns with parallel lines, thus reducing mowing time and increasing mowing efficiency. For regularly shaped surfaces (such as football fields), the parallel-line mowing system proves to be the most efficient. However, when the mowing area has an irregular shape, with curved lines and an undefined geometry (such as golf course's holes), this system loses efficiency, due to high number of turnings, that mark the point when the robot reaches the edge of the area and executes a turn to move onto the next trajectory. The architecture of a golf hole includes a central area, the fairway, which has a curvilinear shape, and an outer ring surrounding it, the semi-rough, which follows the contour of the fairway and is structured as a very narrow band. These two surfaces must be mowed at different heights to ensure proper playing conditions. This requires two separate mowing operations, with the one on the semi-rough being particularly challenging due to its narrow and curvilinear shape. To address this issue, a new mowing system, called Stepcut, was tested to mow the semi-rough area around the fairway with an autonomous mower from Echo Robotics, the TM-2050. The Stepcut system allows the robot to operate along curved concentric lines that follow the geometry of the semi-rough. To compare it with conventional mowing systems, three mowing patterns were studied and analysed: mowing the semi-rough (ring only) with parallel lines (SMR Around), mowing the semi-rough with parallel lines passing over the fairway (SMR Over) and mowing the semi-rough (ring only) using the Stepcut system. Stepcut pattern showed to be the lowest energy consumer, with only 0.572 kWh/ha, while SMR Around and SMR Over consumed, respectively, 0.775 and 1.173 kWh/ha. It also increased the Mowing Efficiency (0.807) and the Real Work Capacity (0.154 ha/h), while SMR Around and SMR Over decreased both, respectively gaining 0.623 and 0.382 of Mowing Efficiency and 0.108 ha/h ad 0.079 ha/h of Real Work Capacity. This study assesses that this new mowing method, the Stepcut, is more efficient and less energy consuming than conventional methods when applied to a surface that follows a curved shape, like a golf course hole.