Dynamics modeling and characteristics analysis of scissor seat suspension

Abstract

Scissor seat suspension is used widely for attenuating the cab vibration of commercial vehicles, and obtaining its dynamics characteristics accurately is the basis of scissor seat suspension optimization, control and development. As a result, this paper focuses on the scissor seat suspension dynamics modeling and characteristics analysis. Firstly, the scissor seat suspension constraint dynamics equations are derived according to the detailed physical structure. Then, a numerical algorithm with the Baumgarte is proposed to solve the derived multi-body dynamics model which considers the correlation between generalized velocity and acceleration in the numerical iteration procedure. Finally, a simplified scissor seat suspension vertical dynamics model is formulated. The “spring equivalent leverage ratio” defined as the ratio of the spring vertical deformation to the relative displacement between the upper base and the lower base, as well as the “damper equivalent leverage ratio” defined as the ratio of the damper vertical velocity to the relative velocity between the upper and lower base, are proposed to study the scissor seat suspension vertical dynamics characteristics. This paper demonstrates that the proposed scissor seat suspension multi-body dynamics model provides a precise dynamics characteristics description, which can be used for the scissor seat suspension structure optimization and virtual product development. Additionally, the proposed simplified scissor seat suspension vertical dynamics model shows benefits for its control strategies development.