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Based on the research and analysis of the current brake systems, this paper presents a novel electro-hydraulic brake system, which can better meet the functional requirements. The system mainly contains a master cylinder, two brake hydraulic cylinders and drive motors, two transmission mechanisms, thirteen solenoid valves, pedal force simulator, etc. Since the proposed brake system uses a dual motor along with two brake hydraulic cylinders, it has advantages in providing fast pressure response, flexible working modes, high precision and strong fault tolerance. In order to facilitate the study of pressure control algorithm for the proposed brake system, a mathematical model of the brake system is firstly established, then a multiplexed time-division pressure control algorithm is proposed to realize the simultaneous or partially simultaneous pressure control, which ensures the high precision and short response time.

To find out the main excitation sources of a bus floor's vibration, modal analysis and spectral analysis were respectively performed in the paper. First we tested the vibration modal of the bus's floor under the full-load condition, and the first ten natural frequencies and vibration modes were obtained for the source identification of the bus floor's vibration. Second the vibration characteristic of the bus floor was measured in an on-road experiment. The acceleration sensors were arranged on the bus's floor and the possible excitation sources of the bus, which includes engine mounting system, driveline system, exhaust system, and wheels. Then the on-road experiment was carefully conducted on a highway under the four kinds of test condition: in-situ acceleration, uniform velocity (90km/h, 100km/h, 110km/h, 120km/h), uniform acceleration with top gear, and stall sliding condition with neutral gear.

Since steering wheel torque feedback is one of the crucial factors for drivers to gain road feel and ensure driving safety, it is especially important to simulate the steering torque feedback for a driving simulator. At present, steering wheel feedback torque is mainly simulated by an electric motor with gear transmission. The torque response is typically slow, which can result in drivers’ discomfort and poor driving maneuverability. This paper presents a novel torque feedback device with magnetorheological (MR) fluid and coil spring. A phase separation control method is also proposed to control its feedback torque, including spring and damping torques respectively. The spring torque is generated by coil spring, the angle of coil spring can be adjusted by controlling a brushless DC motor. The damping torque is generated by MR fluid, the damping coefficient of MR fluid can be adjusted by controlling the current of excitation coil.

This paper presents experimental studies of particulate emissions in a small SI engine fueled with LPG and gasoline fuels. A single cylinder, four-stroke, water-cooled, 125cc EFI engine with gasoline fuel is used as the baseline engine. Characteristics of the particulate emissions of the two fuels are compared. Test results show that: there are great quantities of particulate emissions for both fuels, but the total numbers of particulate emissions for the two fuels are generally in the same level. The distribution of the particulate sizes is in bimodal type for the gasoline, but for the LPG its first peak is not markedly in some conditions. The particulate sizes of the second peak for the two fuels appear at about the same size. At middle loads and 3000r/min, the particulate emissions for both of the two fuels are the greatest.

Based on a 125cm3 single cylinder SI engine, the designated idle speed was controlled by adjusting of cycle ignition advance angle. By analyzing the effects of different idle speed and throttle open position on three way catalyst (TWC) light-off time and conversion efficiency of HC and CO emissions, combined with the corresponding total HC and CO emissions level, the optimum idle speed and throttle open position at engine's warm-up phase were found by the matching optimum. The present method for engine control strategy is helpful to optimize the warm-up phase emission levels in SI engine with LPG fuel.

This paper presents an investigation of cold starts based on a cycle-by-cycle control strategy in an LPG EFI engine. Experiments were carried out in a four-stroke, water-cooled, single cylinder, 125cc SI engine with an EFI system. Effects of the first injection pulse width and the first combustion cycle on the characteristics of the cold-start were analyzed based on the histories of transient engine speeds and cylinder pressures. The study focuses on how to realize the controllable ignition cycle and the single-cycle and multi-cycle combustions were tested based on the single starting injection pulse width. Test results show that the first combustion cycle has an important effect on HC emission and combustion stability of following cycles at cold-start. The injection pulse width is the key factor determining the characteristics of an ignition cycle during the cold-start.

Autonomous driving technology, as the product of the fifth stage of the information technology revolution, is of great significance for improving urban traffic and environmentally friendly sustainable development. Autonomous driving can be divided into three main modules. The input of the decision module is the perception information from the perception module and the output of the control strategy to the control module. The deep reinforcement learning method proposes an end-to-end decision-making system design scheme. This paper adopts the Deep Deterministic Policy Gradient Algorithm (DDPG) that incorporates the Priority Experience Playback (PER) method. The framework of the algorithm is based on the actor-critic network structure model. The model takes the continuously acquired perception information as input and the continuous control of the vehicle as output.

Considering the change of vehicle future power demand in the process of energy distribution can improve the fuel saving effect of hybrid system. However, current studies are mostly based on historical information to predict the future power demand, where it is difficult to guarantee the accuracy of prediction. To tackle this problem, this paper combines hybrid energy management with predictive cruise control, proposing a hierarchical control strategy of predictive energy management (PEM) that includes two layers of algorithms for speed planning and energy distribution. In the interest of decreasing the energy consumed by power components and ensuring transportation timeliness, the upper-level introduces a predictive cruise control algorithm while considering vehicle weight and road slope, planning the future vehicle speed during long-distance driving.

During the vehicle braking, the Regenerative braking system (RBS) transforms the kinetic energy into electric power, storing it in the power sources. To secure the baking process, it is required to use hydraulic braking pressure to coordinately compensate the regenerative braking pressure. The traditional hydraulic pressure control algorithm which is used in regenerative braking system coordinated control has obvious laddering effect in braking. Unit control cycle pressure deviations seriously affect the comfort and the braking feeling on the vehicle.

Alcohols, because of their potential to be produced from renewable sources and their characteristics suitable for clean combustion, are considered potential fuels which can be blended with fossil-based gasoline for use in internal combustion engines. As such, n-butanol has received a lot of attention in this regard and has shown to be a possible alternative to pure gasoline. The main issue preventing butanol's use in modern engines is its relatively high cost of production. Acetone-Butanol-Ethanol (ABE) fermentation is one of the major methods to produce bio-butanol. The goal of this study is to investigate the combustion characteristics of the intermediate product in butanol production, namely ABE, and hence evaluate its potential as an alternative fuel. Acetone, n-butanol and ethanol were blended in a 3:6:1 volume ratio and then splash blended with pure ethanol-free gasoline with volumetric ratios of 0%, 20%, 40% to create various fuel blends.

Acetone-Butanol-Ethanol (ABE), an intermediate product in the ABE fermentation process for producing bio-butanol, is considered a promising alternative fuel because it not only preserves the advantages of oxygenated fuel which typically emit less pollutants compared to conventional diesel, but also lowers the cost of fuel recovery for each individual component during the fermentation. With the development of advanced ABE fermentation technology, the volumetric percentage of acetone, butanol and ethanol in the bio-solvents can be precisely controlled. In this respect, it is desirable to estimate the performance of different ABE blends to determine the best blend and optimize the production process accordingly. ABE fuels with different component ratio, (A: B: E: 6:3:1; 3:6:1; 0:10:0, vol. %), were blended with diesel and tested in a constant volume chamber.

The purpose of this study is to investigate the possibility of acetone-butanol-ethanol (ABE) blended with diesel without further component recovery which has high costs blocking the industrial-scale production of bio-butanol. The combustion characteristics of ABE and diesel blends were studied in a constant volume chamber. In this study, 50% and 80% vol. ABE (without water) were mixed with diesel and the vol. % of acetone, butanol and ethanol were kept at 30%, 60% and 10% respectively. The in-cylinder pressure was recorded using a pressure transducer and the time-resolved natural luminosity was captured by high speed imaging. Combustion visualization using laser diagnostics would provide crucial fundamental information of the fuel's combustion characteristics. With the different percentage of the ABE blended in the diesel, the soot oxidation, the ignition delay and the soot lift-off length were studied in this work.

Active control of low-frequency engine order noise helps to improve the passenger’s sense of hearing, so it has become one of the hot topics in the automotive field. Depth improvement of active noise control (ANC) performance from the perspective of novel algorithms has attracted the attention of researchers. The conventional notch dual-channel filtered-x least mean square (NDFxLMS) algorithm shows acceptable noise reduction for the elimination of engine order noise. To further enhance the steady-state ANC effect, this paper proposed two new notch algorithms: the notch dual-channel filtered-x recursive least square (NDFxRLS) algorithm and the notch dual-channel affine projection (NDAP) algorithm. Vehicle simulation tests show that both the proposed algorithms, especially the NDFxRLS algorithm, have a satisfying performance for the cancellation of interior noise from the engine.

Noise excitation sources are different between electric vehicles and conventional vehicles due to their distinct propulsion system architecture. This work focuses on an interior noise contribution analysis by experimental measurements and synthesis approach using a methodology established based on the principle of noise path analysis. The obtained results show that the structure-borne noise from the tire-road excitation acts as a major contributor to the overall interior noise level, and the structure-borne noise from the power plant system contributes noticeably as well, whereas contributions from the electric motor and tire are relatively insignificant.

In this paper, in order to avoid the frequent switching of engine operating points and improve the fuel economy during driving, this paper proposes a control strategy for the 4-wheel drive (4WD) hybrid vehicle based on wavelet transform. First of all, the system configuration and the original control strategy of the 4WD hybrid vehicle were introduced and analyzed, which summarized the shortcomings of this control strategy. Then, based on the analyze of the original control strategy, the wavelet transform was used to overcome its weaknesses. By taking advantage over the superiority of the wavelet transform method in multi signal disposition, the demand power of vehicle was decomposed into the stable drive power and the instantaneous response power, which were distributed to engine and electric motor respectively. This process was carried out under different driving modes.

Hydraulic retarder, as an auxiliary braking device, is widely used in commercial vehicles. Nowadays, the hydraulic retarder’s internal oil is mainly cooled by the coolant circuit directly. It not only aggravates the load of engine cooling system, but also makes the abundant heat energy not be recycled properly. In this study, an independent energy supply device with organic Rankine cycles is applied to solve the problems above. In the structure of this energy supply device, the evaporator’s inlet and outlet is connected in parallel with the oil outlet and inlet of the retarder respectively. A part of oil enters the evaporator to transfer heat with the organic fluid, and the rest of oil enters the oil-water heat exchanger to be cooled by the coolant circuit. According to the different braking conditions of the retarder, the oil temperature in the inlet of the hydraulic retarder can be kept within the proper range through adjusting the oil flow rate into the evaporator properly.

In order to improve the mode switching performance of parallel hybrid electric vehicles (PHEV) and make better use of the dynamics of the vehicle, this paper proposes a three-stage control method for the start-up mode of start-up, speed synchronization, and clutch slip based on the response characteristics of actual vehicle components and the complex working conditions of the actual road. In the speed synchronization phase, a coordinated control method of “engine speed active following + continuously variable transmission (CVT) speed ratio motor speed limiting” is proposed. The real vehicle test results show that the engine starting-up coordinated control method can significantly accelerate the speed synchronization and shorten the starting-up mode duration during the rapid acceleration, so that the vehicle’s power performance can be well played and the ride comfort can be effectively guaranteed.