Vibration Severity Analysis in a Cabin of a Self-Propelled Sprayer: A Study Considering the Variation in the Forward Speed and the Tire Inflation Pressure in an Ergonomic Context

The mechanical vibrations that occur in agricultural machinery, arising from terrain irregularities or the moving parts of the machine, can harm the operators when they are subjected to work for many hours daily over a period of many years. Excessive exposure to mechanical vibrations often causes low back pain and musculoskeletal problems, and may harm some organs in the human body. In this way, the present research includes the monitoring of four data collection points, considering the front and rear axles of a sprayer, the operator cabin floor and the operator seat in a self-propelled sprayer. The vibration transmissibility between these points is used to measure the vibration severity to which the operator is exposed under different forward speeds and tire inflation pressure conditions. The RMS acceleration levels for both the cabin floor and the operator’s seat were classified as “uncomfortable” and “very uncomfortable” for a workload of 8 h according to the ISO 2631-1, which indicates that the vibration levels that affect the agricultural machinery operator should be reduced. The vibration transmissibility was greater than 1 when measured between the rear axle and the floor of the operating cabin. The vibration transmissibility from the floor to the seat was lower than 1 in all scenarios evaluated, which indicates that seat damping is effective since the vibration severity that affects the operator seat is lower than the vibration severity of the cabin floor.