Design Of Multi-dimensional Vibration Damping Device Of Vehicle Seat Based On Parallel Mechanism

With the rapid development of automobile industry in our country, people focuson ride comfort increasingly in line with self-performance. On account of pavementirregularity, Emergency avoidance or braking, vehicle often causes multi-dimensionalvibration. It affects the ride comfort of vehicle occupants. Seriously, it can threatenhealth and safety of vehicle occupants. Therefore,3-RPC parallel mechanism withdissipative components were selected as the multi-dimensional vibration dampingdevice of vehicle seat, the study in kinematics characteristics of the basing mechanismand vibration performance of the system were carried out, the improvement method ofthe device was put forward, and the parameter optimization was complied.In terms of mechanism design of vibration damping device for vehicle seat,motion output characteristics of basing mechanism were obtained according to trait ofvehicle transport environment. Based on the composition principle of parallelmechanism that took the single-opened-chain as a unit, a series of mechanism with3-dimension translation and their structural characteristics were acquired. Combinedwith application environment of the device, a kind of completely symmetricconfiguration of3-SOC{-R P C-} was chosen as the base of vibration dampingdevice for vehicle seat.In basing mechanism kinematics research, position equations were found on thebasis of D-H method of displacement and homogeneous transformation. Expressionof forward solutions and reverse solutions were set up and the corresponding mutualverification was carried out. Relationship of velocity and acceleration betweenmoving platform center and three moving pairs were gain using derivation method.Then the jacobian matrix of basing mechanism in initial position was obtained, andthe result was verified using influence coefficient method. Judgment of singularconfiguration and analysis of force transmissibility were conducted in the workspace.The results showed this mechanism could work normally and stably.In the vibration characteristics of vibration damping device research, the virtualprototype model for vibration damping device of vehicle seat based on3-RPC parallelmechanism was established utilizing PRO/E and ADAMS software. The model was verified through position equations. Analysis of acceleration transfer characteristicsand impulse-response of the system were studied. And then the influence of systemparameters and loading on three axial acceleration resonance frequency, maximumtransmissibility and peaks of both platforms were obtained. Variations of responsecurve for both platforms of basing mechanism were comparatively analyzed.Combined with experimental research for damping performance of test prototype,results showed that the device could damp multi-dimensional vibration and impulseeffectively.In the optimization of vibration damping device research, the improvementapproach was raised, which symmetrically attached the same structural device to thedownside of upper platform in former device which played the role as dynamicvibration absorber. The corresponding kinetic equation and virtual prototype modelwere built and the mutual verification was executed. System parameters wereoptimized by non-dominated sorting genetic algorithm (NSGA). And then a set ofbest parameters were selected from Pareto optimal solution set which was verified byADAMS simulation. The results showed the damping property of optimized device inlow frequency was highly improved. It could meet the damping demand of differentweight of vehicle occupants and could damp multi-dimensional impulse moreremarkably than former device. In a word, the optimized device could improve ridecomfort of vehicle further.