Mechanical vibrations from uneven field operations are transmitted through the chassis of the harvester to the operator’s seat, potentially leading to adverse health effects, especially under prolonged exposure. This study develops a three-degree-of-freedom dynamic model representing the harvester body and the seat structure. The seat is modeled as a mass-spring-damper system mounted on the harvester frame. The terrain excitation is simulated as a combination of sinusoidal and stochastic signals. The system’s differential equations are solved using the fourth order Runge–Kutta (RK4) method to analyze time-domain vibration responses at the seat location. The vibration level at the seat is assessed in accordance with ISO 2631-1:1997, using Root Mean Square (RMS) acceleration. The results show that seat vibrations can exceed the acceptable threshold in the absence of an appropriate suspension system. Based on these findings, the study proposes the use of the Genetic Algorithm (GA) to optimize the design and operational parameters - including seat mass, stiffness, damping coefficient, and vehicle speed - to minimize the vibration transmitted to the operator. This contributes to improving the working conditions for the agricultural operators, enhancing the machine durability, and increasing the operational efficiency in agricultural environments.
Nguyen et al. (Mon,) studied this question.