Modeling and Optimization of Passive Seat Suspension

This paper deals with modeling and optimization of a working machine seat suspension system parameters. Experimental work in the past shown that it is possible to replace even more complicated, for example parallelogram or scissor mechanisms, with simpler dynamic models of 1 or 1.5 degree of freedom (Zener’s model). Optimization of the damper and spring settings is performed using a two-objective function optimization technique. This enables to minimize not only the exerted vertical vibration acceleration of the seat squab, but also the seat squab relative vertical displacement (stroke) in regard to the working machine cabin. The first component of the objective function expresses comfort of the seat, the second one expresses the safe handling of the working machine. This optimization technique enables to propose so called “soft”, “medium”, or “hard” seat suspensions according to the value of the weighting coefficient. The paper also points on the possibility of improving the dynamic characteristics of the seat with the use of a dynamic vibration absorber. The expediency of its application is especially in working machines without significant changes in the seat excitation frequency spectrum.