Vibration Simulation And Analysis For Automobile Ride Comfort Based On Pseudo Excitation Method

With the development of the social and economic, the vehicles have been one of the important means of transportation in modern time. The ride comfort is a very important indicator of the vehicles, and it can influence the performance of the vehicle's power, handling stability,braking and fuel economy. In order to improve the vehicle' s ride comfort, the ride comfort simulation with its advantages has become an important research topic.The ride comfort simulation and analysis of 1/4 vehicle model,1/2 vehicle model, and complete vehicle model based on Pseudo Excitation Method,the data processing and Spectral analysis of four kinds measured road are major duty in this paper.The vibration simulation significance of vehicle's ride comfort, the related research content in domestic and foreign, and the vibration simulation significance of vehicle's ride comfort by using Pseudo Excitation Method are introduced firstly in the paper; Then the basic principles and characteristics of Pseudo Excitation Method are introduced, and the virtual road excitations corresponding to 1/4 vehicle model,1/2 vehicle model,and complete vehicle model are constructed; the vehicle's mechanical model,the mathematical model and the main specific parameter values of the vehicle models are given; Vibration simulation for the three kinds vehicle model by using Pseudo Excitation Method have operated; with PSD curves of vibration volumes, which are operated by program, the vehicle models'ride comfort are analyzed.The vehicle speed and road roughness are two variable parameters in vehicle model vibration response calculation formula. In order to analyze theirs influence on the vibration response amount, fix one parameter and change the other parameter, then compared the simulation results of 1/2 vehicle model. It is showed that vehicle speed and road roughness rating are the main external factors.With the use of instantaneous frequency response function with space frequency method and calculated-high efficiency PEM, non-stationary random vibration of vehicle model when it moves at variable speed have been simulated. With the obtained three-dimensional power spectrum of non-stationary random vibration response, the conclusion can be showed that; with the vehicle speed increase, the higher frequency is input from road, and spatial low-frequency road excitation plays a major role in vehicle vibration response.The road surface data of four kinds road measured by road spectrum acquisition system for vehicles were pretreated with digital filtering, mean cleaning and trend cleaning processes; and were analyzed, the result shows that:the lower road grade, the greater absolute amplitude parameter value of road elevation data, which performance is that the road is rougher and more uneven. The power spectral density of four kinds measured road were estimated with the usage of Welch method, the power spectral density diagrams show that:when the frequency is in the range of 0-5Hz, the power spectral density reach the maximum. All of these processing and analysis can give certain and actual application in vehicle road ride comfort analysis.The established vehicle vibration simulation model,used solution and corresponding simulation program can better simulate and analyze the vehicle ride comfort. The process and conclusions of analysis can provide certain reference value for vehicles design.