# Precision Agriculture: Assessment of Ergonomic Risks of Assisted Driving System
## 2 Materials and Methods  
In order to evaluate the operator's ergonomic risks, we investigated muscular activation and comfort during the semi-automated driving of the tractor with three different positions of the GSNN display. In particular, the tests were conducted with the display positioned at angles of 30\({}^{\circ}\), 50\({}^{\circ}\), and 80\({}^{\circ}\) relative to the driver's frontal vision, depending on the availability of supports for installing the display (see Figure 1).  
Posture and comfort variations were analyzed through barometric body pressures on the seat, muscular activation by surface electromyography (sEMG), and thermography (IRT) of the back and shoulder muscles of each operator.  
Participation in this study took place on a voluntary basis. The test was conducted on 10 healthy workers with at least 5 years of experience in the field. The exclusion criteria were musculoskeletal disorders, history of scoliosis or spine alterations, acute back pain during the previous four months, recent surgery, and a Body Mass Index (BMI) < 18.5 or >25.  
The operators who underwent a preliminary medical examination had no health problems or pathologies of the column. The experimental tests were conducted using semi-automatic guidance systems to take into account the same agricultural operation: soil narrowing.  
The tests were performed for 15 min at 8.56 \(\pm\) 0.88 km h\({}^{-1}\) in June 2023 on a 3-hectare land strip, with a regular plan and shape, which was previously cultivated for the production of wheat (45\({}^{\circ}\)31\({}^{\prime}\)14\({}^{\prime\prime}\) N, 9\({}^{\circ}\)34\({}^{\prime}\)18\({}^{\prime\prime}\) E), located in Treviglio (BG, Italy) on a farm near the CREA (Council for Agricultural Research and Economics) headquarters. The steering to change direction occurred approximately every 500 m of the road with the tractor. The soil showed uniform physical characteristics [10]: sand (68%), silt (24%), and clay (8%), with stones constituting one-third of the test field. The temperature inside the tractor cab was adjusted to 23 \({}^{\circ}\)C throughout the test. Median soil humidity and resistance to penetration during tests were 20% and 0.97 mPa, respectively. All procedures adhered to the 1964 Helsinki Declaration and its subsequent amendments. The participants provided signed consent, and this study received approval from the Ethics Committee of the University of Catania (code: 321/18). The experimental tests involved crop narrowing using a spring harmony (MAINARDI 400, Mainardi Machine Agricole, Cremona, Italy) attached to a 120-kW tractor (JOHN DERERE 6920s, [PERSON], Moline, IL, USA) equipped with an S-Guide RTK (StarFire6000, [PERSON], Moline, IL, USA) automated steering system. Figure 2  
Figure 1: Scheme of display position at angles of 30\({}^{\circ}\), 50\({}^{\circ}\), and 80\({}^{\circ}\), considering the frontal vision of the tractor driver.  
shows the scheme of this study: 10 operators \(\times\) 3 repetitions (at 30\({}^{\circ}\), 50\({}^{\circ}\), and 80\({}^{\circ}\)), with 30 observations in total (see Figure 2).