Research On Dynamics Modeling And Optimization Of Pure Electric Transport Vehicle

Pure electric vehicles use batteries as the power source,which has the advantage of low energy consumption and no pollution.At present,in the research field of NVH(Noise Vibration and Harshness)performance of pure electric vehicles,the research objects are mostly pure electric passenger cars with centralized motor drive and distributed hub motor drive.The research on the ride comfort of pure electric transport vehicles is less,and it emphasizes the research fields of power system parameter matching optimization,control and energy management,and distribution path optimization.Aiming at the above research status,a pure electric transport vehicle of the enterprise was taken as the research object,and the vehicle dynamics modeling and optimization was researched.The main components are as follows:1.This paper discussed the research background and significance of the topic,introduced the current situation of electric vehicle development and the progress of electric vehicle ride comfort research at domestic and overseas,and further illustrated the main research components and framework structure of this paper.2.According to the test data provided by the enterprise and the basic parameters of each component of the whole vehicle,the dynamics model of the pure electric transport vehicle was established by using ADAMS/Car.Based on the vehicle ride comfort test and evaluation method,the whole vehicle model was simulated with pulse input and random input correspondingly.And then,the obtained simulation test data were compared with the actual vehicle test data.The results show that the established vehicle model is close to the actual vehicle performance and has high credibility,which lays a foundation for the subsequent optimization of the vehicle model.3.Based on the vehicle dynamics model of the pure electric transport vehicle,the minimum value of the root mean square(RMS)acceleration in the y-direction and z-direction at the cab seat was selected as the optimization objective.The installation position of the battery pack was optimized for simulated vehicle speeds of 30 km/h,40km/h,50 km/h,and 60 km/h,respectively.By analyzing the simulation data before and after the optimization,the optimized result of the center of mass coordinates of the battery pack with the simulated vehicle speed of 60km/h was determinable as the final result.According to the optimized result,the battery pack installation position in the whole vehicle model was adjusted.4.Based on the whole vehicle model with optimized battery pack installation position,sensitivity of cab suspension parameters and suspension damper parameters was analysed by using optimal Latin hypercube design,and the six main influencing variables were identified.Then,the multi-objective genetic algorithm NSGA-II was employed to optimize the design of the identified influencing variables.The optimized vehicle model was simulated and analyzed under both concrete and asphalt pavement conditions.The decreasing amplitude in z-weighted acceleration RMS at the driver’s seat reaches over10.5% and 8.9%,respectively,and the decreasing amplitude in total weighted acceleration RMS reaches more than 8.2% and 10.0%,respectively.The decreasing amplitude in the peak of the y-direction acceleration power spectral density curve at the optimized seat reaches more than 9.5% and 9.4%,correspondingly.The decreasing amplitude in the peak of the z-direction curve reaches more than 10.9% and 11.7%,respectively.The results show that the above parameters are significantly degraded compared with those before optimization,and the ride comfort of the vehicle model is effectively enhanced after optimization.5.Integrating both MATLAB and ADAMS/Car through the ISIGHT platform,a prototype system of pure electric transport vehicle simulation and optimization platform was developed.The platform has a simple operating interface and high optimization accuracy.