Journal of Automotive Safety and Energy

Hybrid Electric Vehicles – Current Status and Future Trend

Huei PENG

2015, 6(03): 201-207. doi:10.3969/j.issn.1674-8484.2015.03.001

Abstract ( 381 )

PDF (1352KB) ( 1953 )

The first hybrid electric vehicle (HEV) was built more than 100 years ago. Over the last 15 years,
the technologies have matured and many hybrid passenger cars are offered in US, Japan and China. However
their market shares are still very small in both China and in the US. To make HEVs more successful, they must
become more affordable, and have better performance, so that they can become more competitive compared
with the traditional powertrain vehicles that only run on international combustion engines. This paper reviews
the current status, and discusses several technology concepts to enable multi-planetary gear, multi-mode and
all-wheel drive operations. These concepts likely will help to achieve the needed performance breakthrough.
These concepts are especially important to extend the HEV technologies beyond passenger cars, to light trucks
(LTs) and Sport Utility Vehicles (SUVs).

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Trend of passenger car steering system with electronic control

JI Xuewu, LIU Yahui, YANG Kaiming, HE Xiangkun

2015, 6(03): 201-216. doi:10.3969/j.issn.1674-8484.2015.03.002

Abstract ( 392 )

PDF (1787KB) ( 2390 )

This paper introduces the development of passenger car steering systems with electronic control.
Steering system is the operation device on vehicle with which the driver will get in touch the vehicle. Ergonomics
and drive safety should be taken into account in the development of vehicle steering system. Electronic control
of the steering system is a tendency of the development of passenger car technology and a basic way to
increasing the drive safety and comfort. This paper summarizes the structure and working principle of electric
power steering system, active front steering system, front wheel steer-by-wire system and rear wheel steer-bywire
system respectively in accordance with the progress history of electronically controlled steering systems.
Also, the paper sketches the key technologies, advantages and challenges to be faced of the above-mentioned
steering systems. Finally, it concludes that steer-by-wire system will be the development trend of electronic
control steering system from the point of view of concise construction, convenient layout and correcting driver’s
over operation.

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Evasive manoeuvre for emergency steering based on typical vehicle-pedestrian use case

ZHU Xichan, LIU Zhichao, LI Lin

2015, 6(03): 217-223. doi:10.3969/j.issn.1674-8484.2015.03.003

Abstract ( 415 )

PDF (1531KB) ( 1757 )

An evasive manoeuvre was designed based on typical vehicle-pedestrian use case to help drivers
to get rid of the collision when a pedestrian crosses the road suddenly. A typical vehicle-pedestrian use case
was obtained from 500 risk cases collected from daily driving. According to the characteristics of this typical
risk case, a kind of scenario was built for the development of strategy. A fifth order polynomial was used to plan
a reasonable path for collision avoidance to ensure pedestrian safety. An evasive manoeurve for emergency
steering situation was built based on the combination of feed-forward control strategy and feedback control
strategy to keep the vehicle following the reference path. Combined with a vehicle handing model with two
freedom degrees, the practicability, accuracy and robustness of the manoeurve was verified by a united
simulation in Matlab/Simulink and Carsim environment. The results show that the performance of the steering
strategy acts well when tracking the reasonable reference path so as to avoid the collision between vehicle and
pedestrian.

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Clutch transmitting torque estimation during AMT vehicle starting based on Kalman filter

WU Xuebin, ZHANG Xin, CHEN Hongwei

2015, 6(03): 224-229. doi:10.3969/j.issn.1674-8484.2015.03.004

Abstract ( 310 )

PDF (1447KB) ( 1352 )

A power train dynamics model was built for an automatic manual transmission (AMT) vehicle
to realize the transmitting torque direct control of the automatic clutch. The discrete state space model for
estimating the clutch transmitting torque was derived. The state vector was constituted by the engine rotation
speed and the clutch transmitting torque. The Kalman filtering algorithm was used to estimate the clutch
transmitting torque, to estimate clutch transmitting torque for vehicle starting process, and to analyze estimation
errors by comparing the estimated and simulated values of the clutch torque. Impact of the sample time (5-25 ms)
on clutch torque estimation errors was explored. The results show that the torque estimation error increases
with the increase of sampling time; the lower limit of torque estimation accuracy is 7.5% at sampling time 10 ms.
Therefore, the algorithm show sufficient accuracy.

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Parameter optimization of CRS' seatbelt constraint paths based on design-of-experiment (DOE)

HAN Yong, XIE Jingping, LU Xiaoping, WANG Fang, HUANG Hongwu, MIZUNO Koji

2015, 6(03): 230-236. doi:10.3969/j.issn.1674-8484.2015.03.005

Abstract ( 291 )

PDF (1620KB) ( 1129 )

A method to optimize the parameters of seatbelt constraint paths was built using a design of
experiments (DOE) method to improve the safety performance of a type of seat belt fixed of the child restraint
systems (CRS). A front crash simulation model was set-up using an FE model of CRS and a Hybrid III 3-year
old child dummy. The simulation results were verified with some sled tests. The influences of the seatbelt guide
ring positions, the seat skeleton thickness and the friction coefficient between child and five-point harness on
injury parameters, such as head injury criterion (HIC15) values, chest resultant acceleration and chest vertical
acceleration, were analyzed after improving CRS framework structure, and by using orthogonal experimental
design to select parameters. The results show that the head maximum displacement reduces from 1.5% higher
than the regulation threshold to 15% lower than the threshold. The seatbelt guide ring position is the most
sensitive factor. Therefore, optimizing the seatbelt guide ring position and reducing the friction coefficient can reduce the maximum displacement of the head.

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Lateral impact sled test system for child restraint system based on ECE R129

2015, 6(03): 237-244. doi:10.3969/j.issn.1674-8484.2015.03.006

Abstract ( 387 )

PDF (3220KB) ( 1841 )

According to the requirements on lateral impact test for child restraint system (CRS) in R129, which
was legislated by the Economic Commission for Europe (ECE), lateral impact sled test system was established.
Making use of the rear impact velocity wave generation system, which consisted of the polyurethane tube,
olive-shaped head, initial crash velocity and adjusting wave profile, desired lateral impact test velocity wave
was realized. According to R129, child seat bench and door system were designed, lateral impact tests were
performed on the lateral impact sled test system using the Q3 child dummy, the dummy head and chest
injury were quantitatively measured, the relative velocity curves of test bench and door components, and the
high speed impact video were analyzed. Test results demonstrate that the impact velocity profiles satisfy the
requirements of the R129, the positions of test bench and door are accurate, and the structure components are
stable. Thus, the lateral impact sled test system meets the standards of R129, and can be used for child seat
lateral impact test.

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Mixed dummy model with neck muscle force activation simulation

LI Fan, HU Wei, SU Sicheng, CAO Yingchun

2015, 6(03): 245-249. doi:10.3969/j.issn.1674-8484.2015.03.007

Abstract ( 307 )

PDF (978KB) ( 1203 )

A mixed finite element (FE) dummy model was developed with precise neck muscle geometry as
well as active and passive muscle behavior to investigate neck injury mechanism with muscle activation in
front collision which is important to the design of occupant safety. The model was based on the 50th Hybrid III
dummy with the head and neck replaced by a well-validated biomechanical model. The data of volunteer trolley
collision experiments with a deceleration of 15g, conducted by US Navy Biomechanics Laboratory, was used for
model validation. The results show that the model has a good biofidelity, according to the outputs of head linear
acceleration, angular acceleration and rotational angles of head and neck compared to the volunteer tests.
Therefore, the model can be used to investigate the head-neck injury biomechanics in vehicle frontal impact
considering the activation behavior of neck muscle system.

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Experimental characterization on material mechanical behavior in the hoop direction of 304 stainless steel thin-walled tubes

ZHAO He, XIA Yong, YAO Zaiqi, JIN Jianwei

2015, 6(03): 250-258. doi:10.3969/j.issn.1674-8484.2015.03.008

Abstract ( 274 )

PDF (1972KB) ( 1809 )

Thin-walled 304 steel tube material behavior was investigated experimentally to improve the
technique of tube hydro-forming. A ring hoop tension test (RHTT) system was built, and the simplified analytical
model for the RHTT specimen was analyzed to evaluate the impact of friction and specimen position. The RHTT
specimen strain was measured by using a digital image correlation (DIC) non-contact measurement system.
The RHTT system and data processing method were verified using an isotropic material. The results show that
an “S-shape” style is detected in the measured 304 tube hoop stress strain curve in large plastic deformation
phase and there is significant difference between the material behavior in tube axial direction and that in hoop
direction.

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Scenario prediction of the energy consumption and the environmental emissions of Beijing urban passenger transport

GAO Xiaoling, REN Zhaojun

2015, 6(03): 259-264. doi:10.3969/j.issn.1674-8484.2015.03.009

Abstract ( 293 )

PDF (1043KB) ( 1056 )

The situation of energy consumption and environmental emissions of CO2, CO, CH4, N2O, NOX,
and SO2 was analyzed for the base year 2012 and extrapolated till 2030 for the future predictions within the
framework of the existing urban transport planning and policy in Beijing. Using a computer software called Long-
Range Energy Alternatives Planning System (LEAP) model, USA, established four scenarios of the "Business
As Usual (BAU)", the "Public Transport", the "New Energy Vehicle", and the "Public transport and New energy
vehicle" (P&N). The results of scenario analysis show that with respect to energy saving, the public transport
scenario conducts better than the new energy vehicles scenario, however, the new energy vehicle scenario
performs better than the public transport scenario with respect to the reduction of SO2 emission. Scenario 4
will success to save 45.20% of energy consumption by 2030 compare to BAU, and only emission 47.05% of the
emissions in 2012, so, it has an excellent potential of environmental emissions reduction, especially for SO2 emission.

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Synthetic parameter optimization of hybrid electric vehicle considering electric drive system cost

ZHOU Yunshan, YANG Haojie

2015, 6(03): 265-271. doi:10.3969/j.issn.1674-8484.2015.03.010

Abstract ( 303 )

PDF (1727KB) ( 980 )

A synthetic parameter optimization method of hybrid electric vehicle (HEV) was proposed to solve
the problem that energy management and matching of power system are usually conducted respectively.
Considering the cost of electric drive system and using an improved fuzzy energy management strategy, the
parameters of energy management strategy and the parameters of power system were taken as decision
variables; meanwhile the equivalent synthetic fuel consumption and the cost of motor and battery pack were
taken as objective functions. Then under the simulation environment of ADVISOR, a multi-objective genetic
algorithm was used to find the optimal solution. Simulation results show that under the constrains of vehicle
dynamic quality, the equal fuel consumption per 100km is reduced by 23.0%, the cost of motor and battery pack
is reduced by 41.9%, the CO emissions per kilometer is reduced by 10.8%, the HC emissions per kilometer is
reduced by 22.2%, the NOx emissions per kilometer is reduced by 27.0%, as well as the efficiency of engine and
motor has been improved. These results verify the effectiveness of the method.

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Characteristics of combustion and emissions of the diesel/methanol premixed compound combustion

ZOU Ke, XIANG Xusheng, LI Haiyan, LIU Bingshan

2015, 6(03): 272-279. doi:10.3969/j.issn.1674-8484.2015.03.011

Abstract ( 286 )

PDF (1568KB) ( 1058 )

An inlet injection system of methanol was built in a six cylinder diesel engine to investigate the
combustion and emission characteristics at different substitution rates under the condition of diesel/methanol
compound. The test results show that the combustion characteristics of the engine has changed with the
methanol compound combustion. With the methanol replacement rate increases, the premixed combustion ratio
increases and the diffusion combustion ratio decreases. With the methanol compound combustion, the overall
combustion duration shortened, heat is more focused and improve the combustion content. The methanol
compound combustion can also recover a part of heat from the cooling system, together with the joint effect of
the heat efficiency is greatly improved. However, the high methanol replacement rate will bring the deterioration
of the NOx and CO emissions with the methanol and formaldehyde emissions. The methanol compound
combustion will also delay the cylinder starts burning time, it is have to adjust the main injection timing to ensure
the stable operation of the engine.

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Experiments on the performances and emissions of diesel engine fuelled with diesel/polyoxymethylene dimethyl ethers blends

YANG Hao, LI Xinghu, MU Mingfei, LI Xuehao

2015, 6(03): 280-285. doi:10.3969/j.issn.1674-8484.2015.03.012

Abstract ( 334 )

PDF (1209KB) ( 1414 )

Experimental study was done on the power, economy and emissions characteristics of the diesel
engine fueled with different blend ratio of PODE2-4 blend fuel. Three kinds of blend fuel with different volume
ratio (5%, 10%, and 20%) were tested on a R180 diesel engine without modification, at the speed of 1 200,
1 600, 2 400 r/min and the power load of 20% to 100%. The results show that the diesel engine power and
torque are decreased with the brake speci?c fuel consumption and the brake thermal efficiency increasing when
PODE2-4 blending ratio in the blended fuel increasing. The brake speci?c fuel consumption is increased by
13.6%, with the brake thermal efficiency increasing an average of 1.8% while the diesel engine power and torque
decreasing by an average of 5.3%, when fuel blended 20% PODE2-4. HC and CO emissions are decreased with
exhaust temperature and NOx emissions increased, while extinction coefficient decreased significantly with the
increase of PODE2-4 blending ratio under different loads and speeds conditions. Therefore, PODE2-4 is suit for
using as diesel fuel additive component at low blending ratio.

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Future design and development of domestic automotive fuel cell system

ZHAI Shuang

2015, 6(03): 286-290. doi:10.3969/j.issn.1674-8484.2015.03.013

Abstract ( 316 )

PDF (1222KB) ( 1517 )

The fuel cell stacks from domestic suppliers and international suppliers were compared to develop
a durable and reliable fuel cell system for domestic fuel cell car. The main disadvantages of the fuel cell system
from domestic suppliers were summarized as following: 1) fuel cell system having lower output power with
lower efficiency; 2) Fuel cell stack having lower power density; and 3) Air compressor development lag behind.
Therefore, research and development work for domestic fuel cell system should be focused on the following
aspects: 1) to enhance the fuel cell stack power output and the performance of the air compressor to greatly
improve vehicle performances by operating the fuel cell system in the high efficiency area; 2) to optimize the
system operation condition and the material properties of key components to greatly improve the stack power
density; 3) to realize operating air compressor under low pressure for low power output, and high pressure for
high power output; 4) to elevate the air compressor surge line to operate the air compressor with high efficiency
and high rotation speed.

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