Applied Mechanics and Materials Vols. 253-255

Abstract: Bayesian method was introduced and leaded into the vehicle fault data processing. The parameter estimation and the selection of the optimal distribution model based on Bayesian method were studied, and an example was given. The references are provided for the application of Bayesian method in the large complicated systems, such as vehicle equipments.

Abstract: This article mainly introduces parameter design principle of pure electric vehicle power train. The model of a pure electric vehicle is established in CRUISE. Given motor system and battery system, vehicle performance on various transmission ratio was analyzed and the optimal ratio of transmission was determined. Dynamic performances and driving range of the vehicle was tested, which indicate that the error is smaller than 5% between calculated results and test datum. The rationality of established model is verified. The vehicle driving system meet the research targets, which has good dynamic performance and driving range.

Abstract: A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

Abstract: For the problem that car sub-frame constraint connection complex and effective load more difficult to determine, using finite element and multi-body dynamics ADAMS co-simulation method, Analyzed on a Volkswagen vehicle sub-frame, obtained the accurate load on the sub-frame which are used by engine suspension. The finite element analysis results show that engine load is the greatest impact on the sub-frame stress field, which can be reduced by increasing the area of engine and the sub-frame contacting, thereby prolong the life of sub-frame.

Abstract: In order to establish a real-time hybrid electric vehicle energy management strategy, a LVQ neural network based driving cycles recognizer is established. Selecting 6 typical driving cycles, and the characteristic parameters of the typical driving cycles are extracted and is used to train the LVＱ neural network by LVQ2 algorithm. The trained LVＱ neural network is employed to recognize the other driving cycle. The result shows that the recognition result reflects the character of the real driving cycle very well.

Abstract: In order to study the impact of the suspension damping system on the vehicle riding stability, the PID controlling means for suspension damped neural network is presented, implementing a closed-loop control of yaw stability for vehicles. For the two typical working conditions of single lane changing and step steering, the MATLAB software is used for simulation. The result shows that controlling over the vehicle’s lateral deviation movement through suspension damper, it can reduce significantly the load transfers of both the left wheels and right wheels, so that to effectively restrain a vehicle’s over-steering.

Abstract: A virtual prototype whole-body model was built for a tri-axial heavy-duty truck. Selecting the lateral acceleration, roll angle and yaw rate as the evaluation index, the sensitivity of wheelbase and track was analyzed and the coordinates of hard points were optimized. The Hunting behaviors of the optimized vehicle were discussed and compared with that of the original vehicle. It is shown that the roll angle, yaw rate and vertical acceleration of vehicle body and the vertical acceleration at the seat are reduced greatly after optimization. Thus the vehicle structural optimization improves both handling stability and ride comfort.

Abstract: The diesel engine simulation model build by the GT-POWER software was tested and verified. The advance angle of injection, the opening angle of intake valve and the opening angle of exhaust valve was calculated to get the virtual test sample of diesel engine running under the rated condition. The optimization model was built based on the genetic algorithm, and three parameters were optimized aimed at the economic efficiency under the constraint of the maximum pressure in cylinder and the exhaust temperature; the error between the optimization and the simulation result was below 3%.

Abstract: By theoretical analysis and experiment, this article studied the rebound voltage of lead-acid battery when off-lined. By considering elements as discharge rate, depth of discharge, and environment temperature and so on, we experimented and found the relationship between the rebound voltage and the state of charge (SOC) of battery, which provided reliable basis to estimate the SOC of battery by rebound voltage.

Abstract: The power performance and the fuel economy are both the important indexes of the automobile. To designing a certain vehicle, when the total weight, distribution of the load and the tyres are specified, in traditional ways, it needs to do a lot of the dynamic calculation work and numerous experiments to get the parameters of proper engine and power train. This paper, Based on mathematical model, the simulation for automobile power performance and economy is designed. The calculation on actual vehicle is taken with this software and calculated values are in good agreement with the practical data. The analysis of influence of some chief factors on automobile power performance and fuel economy is carried out, which can provide the reference guide for automobile design.