Table of Content

25 November 2018, Volume 40 Issue 11 Previous Issue    Next Issue

Select

A Study on Coordinated Control of Urban Hybrid Electric SUV Based on Dynamic Characteristics of Components Zeng Xiaohua, Sun Kehua, Li Guanghan, Xiao Lijun, Song Dafeng, Dong Bingbing, Wang Xinming 2018, 40 (11):  1255-1260.  doi: 10.19562/j.chinasae.qcgc.2018.011.001 Abstract ( 188 )   PDF (1289KB) ( 452 )   Save Based on component characteristics and complex driving conditions of vehicle, and aiming at the problem of relative delays in both communication and control, caused by the frequent change in engine dynamic response performance and the differences of communication period between different sub-controllers, a coordinated control scheme is proposed for “the identification of engine dynamic response performance, the prediction of engine response torque and the synchronous compensation of motor”. The results of real vehicle test show that the scheme proposed can reduce the maximum difference of the total output torque of power source relative to total required torque by 43% in the process of engine dynamic response, hence effectively meeting the requirements of power performance and ride comfort of vehicle References | Related Articles | Metrics

Select

An Experimental Study on CNG Combustion Characteristics Using CVB Wu Chongmin, Li Tie, Deng Kangyao 2018, 40 (11):  1261-1266.  doi: 10.19562/j.chinasae.qcgc.2018.011.002 Abstract ( 170 )   PDF (2388KB) ( 344 )   Save Lean burn of compressed natural gas (CNG) can improve its combustion efficiency and lower its combustion temperature, so it is very important to study the control parameters which affect the lean burn of CNG. In this paper, the effects of different air excess factors (AEFs) and different ignition energies on CNG combustion are analyzed by a constant volume bomb combustion test based on schlieren method. The results show that under the same ignition energy, flame propagation speed decreases as AEF increases, and at lean limit point (an AEF of 1.7), the success rate of ignition diminishes with the reduction of ignition energy. In addition, it can be seen from the quantitative analysis on flame propagation that the stronger turbulence can better promote the increase of flame propagation speed References | Related Articles | Metrics

Select

The Effect of Gasoline/Diesel Blends on the Combustion and Emission Characteristics of a Premixed-combustion CI Engine Wang Qiao, Sun Wanchen, Guo Liang, Cheng Peng, Fan Luyan, Li Guoliang, Sun Yi, Du Jiakun 2018, 40 (11):  1267-1274.  doi: 10.19562/j.chinasae.qcgc.2018.011.003 Abstract ( 241 )   PDF (1096KB) ( 477 )   Save An experimental investigation is conducted to study the premixed combustion characteristics and exhaust emission of a turbo-charged common-rail compression ignition engine fuelling with the gasoline/diesel blends. The effect of the gasoline ratio, EGR rate and fuel injection parameters on the combustion process and exhaust emission is explored. The results show that the gasoline/diesel blends can effectively prolong the combustion delay period and shorten the combustion duration, which is beneficial to increase the premixed combustion ratio. Increasing the proportion of gasoline can effectively expand the load range of premixed compression ignition and can reduce the exhaust smoke significantly without causing the increase of NOx. The combination of gasoline / diesel blends and EGR technology is beneficial to reduce NOx and exhaust smoke at the same time. With the introduction of EGR, the emission of NOx shows a linear decreasing trend, and a good smoke emission can be achieved under the condition of low inlet oxygen concentration. At heavy load conditions, using EGR and two stage injection cooperative control strategy and reasonably calibrated pre-injection parameters can further improve the emission of the engine without reducing thermal efficiency References | Related Articles | Metrics

Select

Experimental Study on the Free Spray Characteristics of Intersecting-hole Nozzle in Diesel Engine Xiang Liming, Tian Jiangping, Long Wuqiang, Yuan Wenhua 2018, 40 (11):  1275-1281.  doi: 10.19562/j.chinasae.qcgc.2018.011.004 Abstract ( 181 )   PDF (2165KB) ( 293 )   Save In order to explore the influence of injection pressure, temperature, back pressure and intersecting an-gle on spray pattern of intersecting-hole nozzle, the spray characteristics of both single-hole nozzle and intersecting-hole nozzles are studied in a visible constant volume chamber by using shadowgraph method. The results show that compared with single-hole nozzle, the spray penetrations of intersecting-hole nozzles are smaller and their spray cone angles are larger, and with the increase of the intersecting-angle, the differences become more obvious. With the increase of injection pressure, the differences of spray penetrations between single-hole nozzle and intersecting-hole nozzle reduce, and the larger the intersecting angle, the larger the spray cone angle. At low evaporation temperature, the effects of spray pressure on spray penetration at early stage are more significant, and as the temperature rises, the differences in spray cone angle between single-hole and intersecting-hole nozzles increase, while the differences in spray penetration decrease at early stage. With back pressure going up, the overall trend is the shortening of spray penetration and the rising of spray cone angle, and it has greater influence on the spray characteristics of intersecting-hole nozzle than those of single-hole nozzle References | Related Articles | Metrics

Select

A Study on Carbon Nanotube Reinforced Polyurethane Foam Structure and its Effects on the Improvement of B-pillar Energy Absorption Characteristics Cui An, Sun Wenlong, Li Bin, Cheng Pu 2018, 40 (11):  1282-1287.  doi: 10.19562/j.chinasae.qcgc.2018.011.005 Abstract ( 228 )   PDF (1767KB) ( 318 )   Save In view of the high strength and high stiffness features of carbon nanotubes, a kind of carbon nanotube reinforced polyurethane foam composite is prepared, and test and simulation are conducted to explore the crushing mechanism, energy absorption characteristics and applications of carbon nanotube reinforced polyurethane foam and the compound structure of its filled thin-walled pipe. Then through quasi-static compression test, the load-deflection curves of foams with different proportions of carbon nanotube are obtained, their capabilities of load bearing and energy absorption are compared, and the optimum mass fraction of carbon nanotube added is determined. Next, test and simulation are performed on the energy absorption characteristics of thin-walled pipes and form-filled thin-walled pipes, verifying the effectiveness of FE model for foam-filled structure. Finally carbon nanotube reinforced polyurethane foam is filled into the B-pillar of a car to validate its energy absorption effects. The results show that the maximum intrusion and intrusion velocity of foam-filled B-pillar are obviously reduced, exhibiting good energy absorption feature while meeting lightweight requirements References | Related Articles | Metrics

Select

A Research on the Optimization of Occupant Restraint System Based on Energy Analysis Ge Ruhai, Lin Po, Hong Liang 2018, 40 (11):  1288-1293.  doi: 10.19562/j.chinasae.qcgc.2018.011.006 Abstract ( 183 )   PDF (989KB) ( 217 )   Save An optimization method for vehicle occupant restraint system is proposed based on energy ridedown efficiency analysis in this paper. Firstly MATLAB/Simulink software is used to set up a ridedown efficiency-based energy calculation model. Then on this basis, the relationships between restraint system parameters and the energy ridedown efficiency and injuries of occupant are found. Finally the surrogate model for occupant injury is built, on which an optimization is conducted with a result showing that after optimization the WIC value of occupant injury is 0.365 8, and compared with that (0.387 6) for original model, WID reduces by 5.62% References | Related Articles | Metrics

Select

A Study on the Influencing Factors of Cyclist's Head Injury in Car-Bicycle Accidents Hu Lin, Cheng Qiyin, Huang Jing, Chen Qiang, Zhang Xin 2018, 40 (11):  1294-1301.  doi: 10.19562/j.chinasae.qcgc.2018.011.007 Abstract ( 229 )   PDF (2260KB) ( 285 )   Save In order to investigate the influence of the riding posture on the head injury of cyclist in car-bicycle crash accident, firstly the models for bicycle, cyclist and car are built by using software PC-Crash and simulations on four groups of different ranges of cyclist's back angle are conducted to analyze the effects of riding posture on the injury of cyclist. Then 79 cases of car-bicycle crash accidents are selected from China in-depth accident study (CIDAS) database to analyze the effect of riding posture on the head dynamics response of cyclist in real cases. Finally by using polynomial fitting, the mathematical models of the relationship between the head impact velocity, wrap around distance and injury severity of cyclist and car speed are established for four posture groups. The results show that the injury severity of cyclist increases with the rise of car crash speed, but lowers with the increase of cyclist's back angle References | Related Articles | Metrics

Select

Simulation and Experiment of Hill-start of EPB with Logic Threshold Control Wang Hongliang, Peng Pai, Gu Wenhao 2018, 40 (11):  1302-1307.  doi: 10.19562/j.chinasae.qcgc.2018.011.008 Abstract ( 293 )   PDF (1093KB) ( 416 )   Save A hill start control strategy for pneumatic electronic parking brake (EPB) based on logic threshold control scheme is proposed in this paper. Firstly, the working principle and the hill-start process of EPB are analyzed, the pressure control model of EPB for hill-start is established and the control objective of hill-start is put forward. Then, the characteristics of EPB solenoid valve of tested vehicle are studied and the logic threshold control scheme of pneumatic EPB during hill start is given. Finally, both the co-simulation with Matlab/Simulink and TruckSim and real vehicle test on logic threshold control scheme are conducted. The results of simulation and test show that with the logic threshold control scheme of pneumatic EPB proposed for hill start, the release delay of vehicle braking is shortened, achieving a smoother hill start References | Related Articles | Metrics

Select

Approximate Optimal Torque Vectoring Control for Distributed Drive Electric Vehicles Xie Weidong, Xu Wei, Fu Zhijun, Li Bin 2018, 40 (11):  1308-1316.  doi: 10.19562/j.chinasae.qcgc.2018.011.009 Abstract ( 364 )   PDF (1047KB) ( 605 )   Save In view of the nonlinearity of distributed drive electric vehicle system, a vehicle lateral stability control system based on optimal torque vectoring control is proposed. Firstly magic formula tire model is used to estimate tire forces in real time, and a nonlinear vehicle model with varying tire lateral stiffness is built. Then by using as a reference the optimal control concept of approximate linear quadratic regulator (LQR), a yaw torque control method with adjustable gain is designed based on the lateral acceleration of mass center, and the torque vectoring allocation is performed according to the constraints of motor peak torque and tire friction cycle. Finally both CarSim / LabVIEW co-simulation and hardware-in-the-loop experiment are carried out. The results show that the control system proposed can effectively fulfill the real-time control on vehicle and significantly improve its stability without greatly deteriorating its longitudinal performance References | Related Articles | Metrics

Select

Unsupervised Clustering of Driving Styles Based on KL Divergence Zhu Bing, Jiang Yuande, Deng Weiwen, Yang Shun, He Rui, Su Chen 2018, 40 (11):  1317-1323.  doi: 10.19562/j.chinasae.qcgc.2018.011.010 Abstract ( 330 )   PDF (2716KB) ( 390 )   Save In order to understand the driving style features of different drivers, an unsupervised clustering algorithm for the driving styles of drivers is proposed in this paper based on Kullback-Leibler (KL) divergence. Firstly an acquisition platform for the driving data of drivers in real vehicle test is built, and 84 drivers are tested. Then the driving data of each driver are regarded as a specific Gaussian mixture model (GMM), and whose parameters are estimated by using expectation maximization algorithm. Finally Monte Carlo algorithm is employed to estimate the KL divergence between GMMs, hence the quantitative description on the discrepancies of different drivers is obtained and drivers are clustered into different catagories of style. The results of statistical analysis on the driving data of drivers in each category after clustering show that the unsupervised clustering algorithm proposed can effectively achieve the clustereing of drivers with different driving styles References | Related Articles | Metrics

Select

A Research on Evaluation Method for Vehicle Drivability Quality in Start Condition Huang Wei, Liu Haijiang, Li Min, Tong Ronghui, Zhou Lei 2018, 40 (11):  1324-1329.  doi: 10.19562/j.chinasae.qcgc.2018.011.011 Abstract ( 265 )   PDF (754KB) ( 482 )   Save In order to solve the problem of poor stability of the results of subjective evaluation in vehicle drivability quality evaluation, the start control mechanism is analyzed, the evaluation indicators for drivability quality in start condition are determined. Then the drivability quality evaluation system for start condition is set up and a drivability quality evaluation scheme for start condition is proposed based on fuzzy neural network. Finally the trained evaluation model for drivability quality is validated and the results show that the difference between the score of each vehicle predicted by evaluation model and that of subjective evaluation is within one point, the acceptance rate of prediction scores for different start intentions is up to 90%, and the correlation coefficient between subjective score and predictive score reaches above 0.82, indicating that the evaluation model proposed can fulfill accurate evaluation of drivability quality References | Related Articles | Metrics

Select

A Study on Driver Behavior Identification Method Under Environment of Vehicle-Road Integration Ma Lei, Chen Ke, Wang Minglu, Qu Rui 2018, 40 (11):  1330-1338.  doi: 10.19562/j.chinasae.qcgc.2018.011.012 Abstract ( 303 )   PDF (1096KB) ( 415 )   Save A driver behavior identification method in comprehensive consideration of vehicle handling stability and intelligent transportation system is proposed in this paper. Firstly, the local road network simulation under different driving conditions is achieved by Microscopic traffic simulation software, and massive basic simulation data is obtained. The transformation from basic driving parameters to running status parameters is realized based on the theory of vehicle dynamics. Secondly, neighborhood rough set is applied for feature reduction. Sample data mining is realized by combined use of ensemble empirical mode decomposition (EEMD), correlation coefficient and sample entropy. And the obtained sample entropy value is used as the eigenvectors. Finally, the eigenvectors are put into GG fuzzy clustering for clustering. Then on the basis of the samples, which are obtained by Microscopic traffic software and UC-Win/Road driving simulator, different driver behavior identification is achieved by minimum average closeness degree. Based on the maximum closeness degree and the secondary maximum closeness degree, the driving behavior membership degree of the test sample is calculated. The experiment demonstrates that the method has achieved good effect in driver behavior identification References | Related Articles | Metrics

Select

A Study on Wind Tunnel Test of Interior Aerodynamic Noise Characteristics of a SUV Wang Qiliang, Chen Xin, Lin Qinglong, Wei Hongzhen, Huang Qiuping, Zhang Yingchao 2018, 40 (11):  1339-1345.  doi: 10.19562/j.chinasae.qcgc.2018.011.013 Abstract ( 388 )   PDF (2203KB) ( 543 )   Save In order to study the spatial distribution pattern, frequency characteristics and influencing factors of interior aerodynamic noise of a passenger car for modifying design and lowering noise, a noise test is conducted on a SUV in the wind tunnel of Jilin University. The results show that aerodynamic noise is mainly composed of leakage noise and shape noise, and exhibits spatially symmetric distribution between left and right, but a typical phenomenon is found that the leakage noise at front row is higher than that at rear row, while the shape noise at rear row is higher than that at front row. The sound pressure level of interior noise increases linearly with the increase of wind speed and also goes up with the rise of yaw angle. In the locality on the leeside, the noise obviously deteriorates due to airflow separation becoming severer, while the noise on windward side has just little changes. According to test results, a series of modification schemes for reducing interior noise are adopted, including locally upsizing the sealing belt near A-pillar, plugging the harness hole for rearview mirror with sound insulation foam, using a new-style rearview mirror with a flared shape and a thinner bracket, and pasting damping pieces on door and roof panels. As a result, the interior aerodynamic noise of vehicle is effectively attenuated References | Related Articles | Metrics

Select

An Optimal Field-weakening Control Strategy for Permanent Magnet Synchronous Motor in Electric Vehicles Lin Cheng, Xing Jilei, Huang Zhuoran, Cheng Xingqun 2018, 40 (11):  1346-1353.  doi: 10.19562/j.chinasae.qcgc.2018.011.014 Abstract ( 316 )   PDF (1665KB) ( 1410 )   Save In this paper, a field-weakening control strategy for electric vehicles is proposed with torque control as objective. The characteristic curves of the peak torque and switching torque of motor are obtained by off-line calculation. On this basis and based on feedback speed and target torque, the field-weakened working points in d-q coordinates of motor are constantly updated and move within the region with the curve of the ratio of peak torque over current, current limit circle and the curve of the ratio of peak torque over voltage as boundaries. As a result, the torque response speed and operating efficiency of motor under complex working conditions are enhanced. Simulation with Matlab/Simulink verifies the feasibility of the control strategy proposed and the improvement of vehicle performance References | Related Articles | Metrics

Select

Design and Verification of Fault Diagnosis and Identification System for Automotive Anti-lock Braking System Based on Structural Analysis Method Chen Qi, Yao Zhigang, Qadeer Ahmed, Chen Wuwei, Fan Hao 2018, 40 (11):  1354-1363.  doi: 10.19562/j.chinasae.qcgc.2018.011.015 Abstract ( 193 )   PDF (1982KB) ( 376 )   Save In order to realize the real-time fault diagnosis of automotive anti-lock braking system (ABS) and determine the exact location of key faults, the theory of fault diagnosis by model-based structural analysis (SA) is introduced in this paper to conduct the design and verification of fault diagnosis and identification (FDI) system for automotive ABS. Firstly combining with the mathematical model for ABS and the key faults of system, the fault model for initial system is established, on which the fault detectability and isolability are analyzed by using SA, and for enhancing the capability of fault diagnosis for ABS, the optimal schemes of sensor arrangement are studied. Then the residual error of system is designed with minimal structurally over-determined sets and hence the FDI system for ABS is built. Finally the simulation model for FDI system is set up in MATLAB/Simulink to diagnose and identify the preset faults. The results show that the FDI system can detect and locate all the four key faults preset, with a result consistent with that of theoretical analysis and its feasibility verified References | Related Articles | Metrics

Select

An Analysis on the Modification Effects of Outlet Duct Structure on Vehicle Defrosting Performance Li Ming, Li Guodi, Zhao Weibing, Wang Miao 2018, 40 (11):  1364-1369.  doi: 10.19562/j.chinasae.qcgc.2018.011.016 Abstract ( 228 )   PDF (1780KB) ( 478 )   Save Defrosting effects of windshield is very important for vehicle driving safety and comfort in winter. Through CFD simulation and experiments, this paper aims at studying the effects of outlet duct structure, in particular, the impact angle, i.e. the inclined angle of outlet grid relative to windshield, on the defrosting performance of a sedan under development and equipped with traditional engine or pure electric system. The defrosting effects with different impact angles and temperature rise patterns are compared, verifying the effectiveness of structural modification References | Related Articles | Metrics

Select

An Investigation into Simulation Method of Aerodynamic Noise in Vehicle HVAC Ducts Qing Hongjun, Liu Jie 2018, 40 (11):  1370-1375.  doi: 10.19562/j.chinasae.qcgc.2018.011.017 Abstract ( 275 )   PDF (1997KB) ( 486 )   Save In order to find an efficient and high accuracy simulation method for the aerodynamic noise in vehicle HVAC ducts, three commonly-used methods, i.e. acoustic analogy, direct simulation and co-simulation analysis methods are compared and the effects of sound source surface on the accuracy of acoustic analogy method are emphatically analyzed, based on the standard HVAC duct model co-issued by German vehicle manufacturers Audi, BMW, Daimler, Porsche and Volkswagen. Firstly, RNG turbulence model and SST k-ω DES model are adopted to solve the steady state and transient flow field respectively. Then, the acoustic analogy, direct simulation and co-simulation methods are used to calculate far field radiation noise respectively. The results of simulation and test show that the time-averaged characteristics of flow-field in HVAC duct obtained with RNG turbulence model are overall agree with PIV measurement data and the fluctuated pressure spectra on duct wall surfaces simulated by SST k-ω DES model are basically consistent with test results. Among commonly-used simulation methods, the acoustic analogy method with the penetrable surface surrounding the jet turbulence at duct outlet as sound source surface has the highest accuracy References | Related Articles | Metrics