Effect Of Parameter Uncertainty On Double Powertrain Vibration Isolation System

The design of the powertrain of the double-layer vibration isolation system is a multivariable optimization problem,optimization variables include various passive vibration isolation parameters of vibration isolation elements.Because of the complexity of the structure of double-layer vibration isolation system,parts and components manufacturing error and measurement is not accurate,the uncertainty of material itself physical properties,and the error of the diesel engine vibration force analysis and calculation,and so on factors,structure parameters and excitation source is often uncertain,however in the powertrain of double-layer vibration isolation system of the design process,often according to the determined parameters on the performance of vibration isolation system is studied. Parameters of the actual value and design value,there must be some deviation,so the actual vibration isolation performance of the system and the design to calculate the vibration isolation performance of the system must exist a certain deviation.Therefore all parameters of the vibration isolation system based on uncertainty analysis, get the uncertainty factors of the influence of the parameters deviation range set of parameter variation range and uncertainty factors, and on the basis of the deterministic parameter design,the change of each system parameter and the probability distribution for the effect of vibration isolation performance,thereby design parameters can be chosen reasonably,improve the system performance of vibration isolation, simplify the optimal design process.In this paper, the following work is mainly carried out on the study of the powertrain double layer vibration isolation system:(1)Analysisde the dynamic model and the mathematical model of the double layer vibration isolation system,selected the mathematical model for the research object of this article and the uncertainty parameter analysis method.(2)Using MATLAB software to write the program to calculation double-layer vibration isolation system’s uncertainty parameter, contains the analysis of the vibration force、the analysis of static equilibrium of double-layer vibration isolation system、the analysis of intrinsic characteristics of double-layer vibration isolation system、the forced vibration characteristic analysis of double-layer vibration isolation system,then through the calculation of uncertainty for the verification.(3)Based on Monte Carlo simulation method to study the influence of power package vibration force when the quality of the internal combustion engine piston,the crankshaft rotating mass,the crank angle and the power changes in their allowed error range.(4)Based on Monte Carlo simulation method to study the influence of Double-layer vibration isolation system static balance,the inherent characteristics,forced vibration characteristics when the dynamic exciting force,the two-stage vibration isolation device centroid position deviation,the base of processing error,the two stage vibration isolator stiffness, two-stage vibration isolation damper and the two-stage vibration isolation device quality,the moment of inertia of two-stage vibration isolation device changes in their allowed error range.(5)Based on Monte Carlo simulation method to study the relationship between the impact of the double isolation system transmissibility and the two anti-vibration device quality、two anti-vibration device inertia、two isolator stiffness、two vibration damping when them changes within the error range of 0～1,get the value of each impact parameter uncertainty error value corresponding to the two-layer vibration isolation system transfer rate graph diagram,that layer vibration isolation system transfer rate for each uncertain parameter variations sensitivity,so in the double isolation system design process we can provide advice to individual processing parameters uncertain.The variation of the mass of the two stage vibration isolation device in the error range of 20% is very small,and the other three factors, along with the error range is increased transfer rate changes also affected with the increase.(6)Based on the research of single factor and multiple factors,using comparative method, the method to get the uncertain parameters of dynamic vibration force,vibration isolation system static balance and natural features of vibration isolation system and isolation system affects the size of the forced vibration characteristics,and then sorting.(7)Summarizes each parameter uncertainty on power packs exciting force,vibration isolation system static equilibrium, the inherent properties of vibration isolation system, dynamic reaction force,vibration intensity of effect size,to give to each parameter uncertainty within the permissible error range affect the relationship between vibration isolation performance of the double vibration isolation system.The study shows the most influential factors on the maximum effect of the double layer vibration isolation system is the rotation inertia error of two stage vibration isolation device, The second influential factors is the error of two stage vibration isolator stiffness, when the error range of the two stage vibration isolation device is less than 20%,the influence of the vibration isolation system is very small.In summary,the study of uncertainty parameters of the double-layer vibration isolation system,has certain engineering practical value,provides basic data and reference for semi-active control and active control of double layer vibration isolation system.