Research On Vibrtion Characteristic Of Seat Suspension System Based On Air Spring And Mr Damper

The problems of vehicle's vibration become more and more serious with the speed and load increasing. Vibration has a great extent influence on the health of the human body and will reduce working efficiency.Based on SK37-6 type diaphragm air spring produced by ContiTech company, the air spring with auxiliary chamber system was established through a tube and a orifice. Air spring with auxiliary chamber system and RD-1005-3 type magnet rheological (MR) fluid damper which produced by LORD company were added to a scissors linkage seat to establish the new kind of intelligent driver's seat suspension for improving work and run environment. The theory model of the system was set up. Through simulation and experimental, its vibration characteristic was studies, the achieved results is as follows:1. The equation of the seat suspension with air spring and MR damper was established based on the non-linear dynamics theoretical model of air spring with auxiliary chamber and D'Alembert principle. Equivalent stiffness, equivalent damping, natural frequency of vibration and damping ratio of vibration system were leaded out, and use MATLAB command function edit M files to solve the equivalent stiffness, equivalent damping, natural frequency and damping ratio of the seat suspension with different air spring pressure,different input current and different throttle open. And influential factors and influential laws on the system's dynamic characteristics have been analyzed in details.2. And a simulation model of seat suspension with air spring system and MR damper was established in ADAMS, the vibration characteristic of suspension system of the seat with different air spring pressure, different input current and different throttle opening were analyzed. The research results show that the vertical stiffness and damping of the air-spring can be changed obviously by adjusting the size of the throttle fixed between the air-spring and an auxiliary chamber.3. Based on the result of simulation, the experimental system of driver's seat suspension with air spring with auxiliary chamber and MR damper of seat was established, the dynamic characteristic of suspension system of the seat was systematically researched. The dynamic characteristic of suspension system of the seat with different air spring pressure,different input current and different throttle open was analyzed, and compared with the simulation result, the achieved results is as follows:The displacement and acceleration amplitude of experimental and simulation are consistent, but displacement and acceleration of responding were all later than simulation result about 1/4 periods. If the system is in vibration isolation zone, the displacement transmissibility decreases with the increasing of throttle opening. When the throttle opening is less than or equal to 45°,the displacement transmissibility keep the same with the increasing of throttle opening. If the excitation frequency is low, under the same inner pressure and throttle opening, the displacement transmissibility decreases with the increasing of input current of MR damper. If the system is in vibration isolation zone, under the same inner pressure and throttle opening, the displacement transmissibility increases with the increasing of input current of MR damper. When the excitation frequency is less than 3Hz, the throttle opening and the input current of MR damper have no effect on the acceleration root of mean squares. If the excitation frequency is more than 3Hz, the acceleration root of mean squares decrease with the decreasing of throttle opening. When the throttle opening is less than or equal to 45°, the acceleration root of mean squares keep the same with the increasing of throttle opening. If the excitation frequency is higher than 5Hz, the acceleration root of mean squares decreases with the increasing of excitation magnitude.This study could be reference and guide and provide a theoretical basis for the research of control methods, control strategies, as well as the design of control unit for intelligent driver's seat suspension with air spring with auxiliary chamber and MR damper.