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A new range-extension hybrid powertrain concept, namely the Tongji Extended-range Hybrid Technology (TJEHT) was developed and demonstrated in this study. This hybrid system is composed of a direct-injection gasoline engine, a traction motor, an Integrated Starter-Generator (ISG) motor, and a transmission. In addition, an electronically controlled clutch between the ISG motor and engine, and an electronically controlled synchronizer between the ISG motor and transmission are also employed in the transmission case. Hence, this system can provide six basic operating modes including the single-motor driving, dual-motor driving, serial driving, parallel driving, engine-only driving and regeneration mode depending on the engagement status of the clutch and synchronizer. Importantly, the unique dual-motor operation mode can improve vehicle acceleration performance and the overall operating efficiency.

In recent years, particulate matters (PM) emissions from gasoline direct injection (GDI) engines have been gradually paid attention to, and the hydrous ethanol has a high oxygen content and a fast burning rate, which can effectively improve the combustion environment. In addition, Exhaust gas recirculation (EGR) can effectively reduce engine NOx emissions, and combining EGR technology with GDI engines is becoming a new research direction. In this study, the effects of hydrous ethanol gasoline blends on the combustion and emission characteristics of GDI engines are analyzed through bench test. The results show that the increase of the proportion of hydrous ethanol can accelerate the burning rate, shorten the combustion duration by 7°crank angle (CA), advance the peak moment of in-cylinder pressure and rate of heat release (RoHR) and improve the combustion efficiency. The hydrous ethanol gasoline blends can effectively improve the gaseous and PM emissions of the GDI engine.

To meet the request of China National 6b emission regulations which will be officially implemented in China, firstly including the RDE emission test limits, the transient emissions on real road condition are paid more attention. A non-plug-in hybrid light-duty gasoline vehicles (HEV) sold in the Chinese market was selected to study real road emissions employed fast response NOx analyzer from Cambustion Ltd. with a sampling frequency of 100Hz, which can measure the missing NO peaks by standard RDE gas analyzer now. Emissions from PEMS were also recorded and compared with the results from fast response NOx analyzer. The concentration of NOx emissions before and after the Three Way Catalyst (TWC) of the hybrid vehicle were also sampled and analyzed, and the working efficiency of the TWC in real road driving process was investigated.

Tracking vehicle trajectories is essential for autonomous vehicles and advanced driver-assistance systems to understand traffic environment and evaluate collision risk. In order to reduce the position deviation and fluctuation of tracking on-road vehicle by millimeter-wave radar (MMWR), an interactive multi-model Kalman filter (IMM-KF) tracking algorithm including data association and track management is proposed. In general, it is difficult to model the target vehicle accurately due to lack of vehicle kinematics parameters, like wheel base, uncertainty of driving behavior and limitation of sensor’s field of view. To handle the uncertainty problem, an interacting multiple model (IMM) approach using Kalman filters is employed to estimate multitarget’s states. Then the compensation of radar ego motion is achieved, since the original measurement is under the radar polar coordinate system.

Water and thermal management is an essential issue that influences performance and durability of a polymer electrolyte membrane fuel cell (PEMFC). Water content in membrane decides its ionic conductivity and membrane swelling favors the ionic conductivity, resulting in decreases in the membrane’s ohmic resistance and improvement in the output voltage. However, if excessive liquid water can’t be removed out of cell quickly, it will fill in the pores of catalyst layer (CL) and gas diffusion layer (GDL) then flooding may occur. It is essential to keep the water content in membrane at a proper level. In this work, a transient isothermal one-dimensional model is developed to investigate effects of the relative humidity of inlet gas and cell temperature on performance of a PEMFC.

The thermophysical parameters and amount of composite phase change materials (PCMs) have decisive influence on the thermal control effects of thermal management systems (TMSs). At the same time, the various thermophysical parameters of the composite PCM are interrelated. For example, increasing the thermal conductivity is bound to mean a decrease in the latent heat of phase change, so a balance needs to be achieved between these parameters. In this paper, a prismatic LiFePO4 battery cell cooled by composite PCM is comprehensively analyzed by changing the phase change temperature, thermal conductivity and amount of composite PCM. The influence of the composite PCM parameters on the cooling and temperature homogenization effect of the TMS is analyzed. which can give useful guide to the preparation of composite PCMs and design of the heat transfer enhancement methods for TMSs.

This paper presents a theoretical study of a finite hybrid piezoelectric phononic crystal (PC) beam with shunting circuits. The vibration transmissibility method (TM) is developed for the finite system. The uniform and non-uniform configurations of the resonators, piezoelectric patches and shunting circuits are respectively considered. The properties of the vibration attenuation of the hybrid PC beam undergoing bending vibration are investigated and quantified. It is shown that the proper relaxation of the periodicity of the PC is conducive to forming a broad vibration attenuation region. The hybrid piezoelectric PC combines the purely mechanical PC with the piezoelectric PC and provides more tunable mechanisms for the target band-gap. Taking the structural and circuit parameters into account, the design of experiments (DOE) method and the multi-objective genetic optimization method are employed to improve the vibration attenuation and meet the lightweight demand of the attachments.

With increasing pressure from environment problem for reduction in CO2 emissions and stricter fuel targets from road vehicles, new transmission technologies are gaining more attention in different main market. To get suitable road load data for transmission durability development is becoming increasingly important and can shorten the development time of new transmission. This paper presents the procedure and methods of road load data development for durability design of transmission product and optimization based on the real road data measurement, statistical characteristics evaluation and fatigue damage equivalency. Apply this road load data method procedure on 3 type of vehicle which represent conventional vehicle, BEV and HEV.

Multi-sensor information fusion framework is the eyes for unmanned driving and Advanced Driver Assistance System (ADAS) to perceive the surrounding environment. In addition to the perception of the surrounding environment, real-time vehicle localization is also the key and difficult point of unmanned driving technology. The disappearance of high-precision GPS signal suddenly and defect of the lane line will bring much more difficult and dangerous for vehicle localization when the vehicle is on unmanned driving. In this paper, a road boundary feature extraction algorithm is proposed based on multi-sensor information fusion of automotive radar and vision to realize the auxiliary localization of vehicles. Firstly, we designed a 79GHz (78-81GHz) Ultra-Wide Band (UWB) millimeter-wave radar, which can obtain the point cloud information of road boundary features such as guardrail or green belt and so on.

For internal combustion engine systems, lean and diluted combustion is an important technology applied for fuel efficiency improvement. Because of the thermodynamic boundary conditions and the presence of in-cylinder flow, the development of a well-sustained flame kernel for lean combustion is a challenging task. Reliable spark discharge with the addition of enhanced delivered energy is thus needed at certain time durations to achieve successful combustion initiation of the lean air-fuel mixture. For a conventional transistor coil ignition system, only limited amount of energy is stored in the ignition coil. Therefore, both the energy of the spark discharge and the duration of the spark discharge are bounded. To break through the energy limit of the conventional transistor coil ignition system, in this work, an adaptive spark ignition system is introduced. The system has the ability to reconstruct the conductive ion channels whenever it is interrupted during the spark discharge.

Proton exchange membrane fuel cell (PEMFC) system is expected to be the next generation vehicle powertrain. However, water management is still the main problem which directly affects the performance, reliability and durability in PEMFC system. To ensure the accurate water content estimation, High Frequency Resistance (HFR) is the most representative indicator in laboratory. The HFR is calculated by detecting the Alternating Current (AC) voltage response of fuel cell under the excitation of 1k Hz AC current. The voltage level of the AC excitation affects the measurement of HFR. Generally, 5mV AC excitation is used to measure HFR for the fuel cell with an output voltage between 0.6-1V. So, online HFR monitor is a big challenge for vehicle application, due to its low Signal/Noise Ratio (S/N), poor Electromagnetic Compatibility (EMC) environment, high common mode voltage and several hundred cells. In this work, an online fuel cell HFR monitor controller is developed.

Hot forming process of ultrahigh strength boron steel 22MnB5 is widely applied in vehicle industry. It is one of the most effective approaches for vehicle light weighting. Dynamic recovery is the major softening mechanism of the boron steel under austenite state at elevated temperatures. Deformation mechanism of the boron steel can be revealed by investigation on the behavior of dynamic recovery, which could also improve the accuracy of forming simulations for hot stamping. Uniaxial tensile experiments of the boron steel are carried out on the thermo-mechanical simulator Gleeble3800 at elevated temperatures. The true stress-strain curves and the relations between the work hardening rate and flow stress are obtained in different deformation conditions. The work hardening rate decreases linearly with increasing the flow stress.

Thin-walled structures have been widely used in automobile body design because of its good lightweight and superior mechanical properties. For the energy-absorbing box of the automobile, it is necessary to consider its working conditions under the axial and oblique impact. In this paper, a novel hierarchical honeycomb is proposed and used as filler for thin-walled structures. Meanwhile, the crashworthiness performances of the conventional honeycomb-filled and the hierarchical honeycomb-filled thin-walled structures under different impact conditions are systematically studied. The results indicate the energy absorption of the hierarchical honeycomb-filled thin-walled structure is higher than that of the conventional honeycomb-filled thin-walled structure, and the impact angle has significant effects on the energy absorption performance of the hierarchical honeycomb-filled structure.

The present work discusses a novel oxy-fuel combustion cycle utilized in compression ignition internal combustion engine. The most prominent feature of this cycle is that the air intake is replaced by oxygen; therefore nitric oxide (NOX) emission is eliminated. The enrichment of oxygen leads to higher flame speed and mass fraction consumption rate; on the other hand, the high concentration of oxygen presented during combustion will result in intense pressure rise rate which may cause severe damage to engine hardware. As water injection is already utilized in gasoline engine to control knocking, the utilization of water injection in optimizing oxy-fuel combustion process has been tested in this study. To understand the relationship between water injection strategy and cycle efficiency, computational fluid dynamics (CFD) simulations were carried out. The model was carefully calibrated with the experimental results; the errors were controlled within 3%.

The action of load on the component is crucial to evaluate the performance of durability. Another factor that affects fatigue life is the boundary conditions of the test specimen being tested by introducing unrealistic loads on the component of interest. The physical test is widely conducted in the laboratory. The fixture provides additional constraints on the test specimen as well as reaction forces to balance the test system [1]. The characteristics of the fixture involved in the test is important to analyze and assess the test results [2]. The impact of the reaction force of the fixture on the spindle-coupled axle road simulation test is presented in this article. A simplified 7-DoF (degrees of freedom) model is introduced to demonstrate the dynamic behavior of the vehicle. The influence on the internal load by the fixture has been analyzed. Followed by a more detailed MBS (multibodysystem) model to give a thorough understanding of the phenomenon.

For an electric vehicle driven by four in-wheel motors, the torque of each wheel can be controlled precisely and independently. A closed-loop control method of differential drive assisted steering (DDAS) has been proposed to improve vehicle steering properties based on those advantages. With consideration of acceleration requirement, a three dimensional characteristic curve that indicates the relation between torque and angle of the steering wheel at different vehicle speeds was designed as a basis of the control system. In order to deal with the saturation of motor's output torque under certain conditions, an anti-windup PI control algorithm was designed. Simulations and vehicle tests, including pivot steering test, lemniscate test and central steering test were carried out to verify the performance of the DDAS in steering portability and road feeling.

A Controllable Active Thermo-Atmosphere (CATA) Combustor enables the investigation of stabilization mechanisms in an environment that decouples the turbulent chemical kinetics from the complex recirculating flow. Previous studies on combustion of the low-pressure fuel jets in the Controllable Active Thermo-Atmosphere (CATA) showed non-linear effect of coflow temperature on autoignition delay and the randomness of autoignition sites. In this work, a diesel spray is injected into the CATA with the injection pressure at 20MPa from a single-hole injector and the autoignition and combustion process of the spray is recorded by a high-speed camera video. The multipoint autoignition of diesel spray is observed in the CATA and the subsequent combustion process is analyzed. The results show that autoignition phenomenon plays an important role in the stabilization of the lifted flames of diesel spray under low coflow temperature.

By changing the top-land radial clearance, this paper presents the effect of the piston crevice on the transient HC emissions of the first firing cycle at cold start on an LPG SI Engine. A fast-response flame ionization detector (FFID) was employed to measure transient HC emissions of the first firing cycle. At the same time, the transient cylinder pressure and instantaneous crankshaft speed of the engine were measured and recorded. The results show that increasing 50% crevice volume leads to 25% increase of HC emissions in the lean region and 18% increase of HC emissions in the rich region, however, the 50% increase of crevice volume contributes to 32% decease of HC emissions in the stable combustion region. For LPG SI engine, the HC emissions of the first firing cycle during cold start are relatively low in a wide range of the excess air ratio.

The effectiveness of after-treatment systems depends on the exhaust gas temperature, which is low during cold-start. As a result, Euro III, Euro IV and FTP75 require that the emissions tests include exhaust from the beginning of cold start. It is proved that 50%∼80% of HC and CO emissions are emitted during the cold start and the amount of unburned fuel from the crevices during starting is much higher than that under warmed engine conditions. The piston crevices is the most part of combustion chamber crevices, and results of mathematical simulations show that the piston crevice contribution to HC emissions is expected to increase during cold engine operation. Based on the transient HC test data and the double zone combustion model, this paper presents the study of the crevice HC Mechanism of the first firing cycle at cold start on an LPG SI Engine. A fast-response flame ionization detector (FFID) was employed to measure transient HC emissions of the first firing cycle.

In this paper, a case study of Shanghai HEVs application and its effects on the social and environmental benefits are presented based on the multi views on the different aspects, such as, not only for the fuel consumption saving, but also emissions reduction and health effect, agriculture loss and cleaning cost. The results show that the potential benefits for the society from HEVs application are markedly with the increase of the ratio of HEV in the population of vehicle. Based on this, the policy to promote the HEV purchased by consumers is very important at the beginning of HEV into market.