Research On Automobile Seat Vibration Isolation Based On Positive And Negative Stiffness Springs Parallel

Seat is an important part of automobile vibration isolation,has an effect on the comfort of the automobile.Designing superior seat vibration isolation components is important to improve the vehicles comfort.Traditional linear passive vibration control components such as metal spring have simple structure,low cost,but its frequency band is narrow,has weak self-adaptive ability.The new active control vibration isolation has a good effect,but it has a large energy-consuming and is difficult to control.The nonlinear passive control components can solve these problems.New positive and negative stiffness parallel vibration isolation system is a nonlinear passive vibration control system,has tremendously significance to improve vehicle comfort.New automobile seat spring component was designed based on the principle of stiffness offset with the positive and negative stiffness parallel.Mathematical model and mechanical model were established for the analysis.The principle is to parallel the positive and negative stiffness spring,the positive stiffness was used as bearing spring,and the negative stiffness spring is used to offset the positive stiffness,so that the total stiffness and natural frequency are decreased,which satisfies automobile seat vibration requirements.This thesis built a mechanics model with virtual prototype software ADAMS,and sine excitation is used to analog the input signal of automobile cabin floor to carry out the simulation analysis.The relations between seat amplitude and link length,seat amplitude and stiffness of the springs,seat amplitude and amplitude of incentive were obtained.This relation curves are futher analyed.Provide a basis for designing the mechanism.The mechanism was optimized with uniform design.The better parameters are obtained under less experiment conditions.The result shows that a better vibration isolation effect is obttain.The virtual prototype of the five degrees of freedom human body-seat model was established with ADAMS.It is added with positive and negative stiffness parallel vibration isolation system and positive stiffness parallel vibration isolation system separately.The accelaration curves of the head,upper torso,lower torso,thighs and seat is obtained by simulation.Simulation results show that the proposed system outperforms the ordinary seat isolation system,and human body acceleration is obviously decreased and comfort is effecitvely improved.The spring using on negative stiffness menchanism was designed.