Abstract
<jats:p>The problems of vibrations arising during the operation of ground machines are relevant. Seat vibration isolation systems are used to protect operators from vibrations. The purpose of the study was to develop a methodology for optimizing the nonlinear characteristics of a vibration protection system for an operator’s seat with one translational degree of freedom in the vertical direction. A mathematical model of a vibration protection system with nonlinear rigidity and damping characteristics was used. The functions of the stiffness force and damping coefficient of the vibration protection system were described by two-point Hermite splines. To kinematically excite the movement of the system, sinusoidal oscillations of the seat base were used with an amplitude slowly increasing from zero to a maximum value. The amplitude of the base vibrations, at which the absolute acceleration of the seat reaches the limit value determined by sanitary standards, is called the output amplitude. Based on the output amplitude, for each value of the base oscillation frequency the value of the relative output amplitude was determined. The latter was the ratio of the current output amplitude, determined for given values of the parameters of the nonlinear characteristics of the seat, to the maximum value of the output amplitude, which was achieved over the entire set of combinations of the studied values of the parameters of the nonlinear characteristics of the seat. To assess the effectiveness of the vibration protection system, the sum of the relative amplitudes of the base out-put at all studied low frequencies in the range of up to four Hertz was used as a criterion. For each combination of parameters describing the nonlinear stiffness and damping characteristics, and for each frequency value from the range under study, the amplitude of the base output was determined. Relative output amplitudes were calculated. The values of the relative output amplitudes were summed up for all frequencies under study with a resolution of one tenth of a Hertz. Optimization of the characteristics of the seat vibration protection system made it possible, using the example of a limited range of parameters using an exhaustive search method, to in-crease the value of the complex optimization criterion by more than 3.5 times. The work may be of interest to developers of vibration protection systems for operator seats.</jats:p>