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In order to realize the shift control of dual-motor hybrid electric vehicle (HEV), a non-power interruption shift control method based on three-power source coordination control was proposed by analyzing the shift process of dual-motor hybrid configuration. The shift control process was divided into three stages: oil-filling self-learning stage, torque exchange stage and inertia control stage. In the torque exchange stage, the characteristics of the speed stage and torque stage were analyzed, which was different from the traditional method's dependence on pressure sensor, longitudinal acceleration sensor and engine torque accuracy. A shift clutch gain self-learning strategy based on shift time and input shaft speed soaring problem was proposed.

In order to achieve seamless mode switching control for hybrid electric vehicles (HEVs) in the event of battery failure, we propose a motor voltage-controlled mode switching method that eliminates power interruptions. This approach is based on an analysis of the dual-motor hybrid configuration's mode switching. We analyze the overall vehicle operation when the high-voltage battery occurs in different hybrid modes. To ensure that the vehicle can still function like a conventional car under such circumstances, we introduce a novel "voltage control" mode. In this mode, instead of operating in its traditional torque control manner, the P1 motor adopts a voltage control strategy. The P1 controller's variable becomes "voltage," and VCU sends the motor's working mode switching request and PCM finishes the mode transition. During system operation, the P1 motor promptly responds to these target voltages to maintain bus voltage within a normal range.

In order to realize the series-parallel switching control of hybrid electric vehicle (HEV) with dual-motor hybrid configuration, a method of unpowered interrupt switching based on the coordinated control of three power sources was proposed by analyzing the series-parallel driving mode of the dual-motor hybrid configuration. The series to parallel switching process is divided into three stages: speed regulation stage, clutch combination and power source switching. The distribution control of speed regulating torque is carried out in the speed regulating stage. The speed adjustment torque is preferentially allocated to the power source of the input shaft (engine and P1) to carry out the lifting torque. Due to the high speed adjustment accuracy and fast response of the P1 motor, the input shaft is preferentially allocated to P1 for speed adjustment, that is, the torque intervention of P1.

The strategy for emission reduction in the P2.5 hybrid system involves the optimization of engine torque, engine speed, catalyst heat duration, and motor torque regulation in a coordinated manner. In addition to employing traditional engine control methods used in HEV models, unique approaches can be utilized to effectively manage emissions. The primary principle is to ensure that the engine operates predominantly under steady-state conditions or limits its load to regulate emissions levels. The main contributions of this paper are as follows: The first is the optimization of catalyst heating stage. During the catalyst heating stage, the system divides it into one or two stages. In the first stage, the vehicle is driven by the motor while keeping the engine idle. This approach stabilizes catalyst heating and prevents fluctuations in air-fuel ratio caused by speed and load changes that could potentially worsen emissions performance.

A vehicle vibration issue emerged for a hybrid prototype during low speed driving in EV mode. This work is focused on the effort to identify the root cause and resolve the issue. The endeavor begins by performing a motor test in moderate acceleration with an imposed constant torque load. All relevant information is simultaneously recorded, including vehicle speed, vibration of motor structure and seat track, motor rpm, voltage and current signals, etc. Then analyses are carried out to strive for a better understanding of the vibration characteristics and identify its mechanism. It is found that the torque ripple from the driving motor is the root cause of the low speed vehicle vibration in EV mode, and the torque ripple is found to be induced by the current distortion resulted from the current sensor drift and electromagnetic interference due to high current signals.

Engine torque fluctuation is a great threat to vehicle comfort and durability. Former researches tried to solve this problem by introducing active damping system, which means the motor is controlled to produce torque ripple with just the opposite phase to that of the engine. By this means, the torque fluctuation produced by the motor and the engine can be reduced. In this paper, a new method is raised. An attempt is proposed by changing the traditional structure of the motor, making it produce ripple torque by itself instead of controlling the motor. In this way a special used ISG (Integrated Starter Generator) motor for HEV (Hybrid Electrical Vehicles) is made to achieve active damping. In order to study the possibility, a simulation, which focus on the motor instead of the whole system, is developed and series-parallel configuration is used in this simulation. As for the motor that used in this paper, four kinds of motors have been investigated and compared.

This paper presents an investigation of drivability issue of engine start-stop. Hybrid vehicles provide excellent benefits regarding fuel efficiency and emission. However, vibration results from constant engine start and stop events generate drivability issues, thus compromising driving comfort. This paper has designed a high speed torque sensor to capture instantaneous torque at the engine shaft. Its consequences help to find out the most suitable index of vibration severity. This paper is organized in four sections. The first section introduces the powertrain to be studied. The second section introduces development of a specially designed torque sensor. The torque sensor is installed between the engine and ISG (Integrated Starter Generator), alongside with an encoder. The torque sensor is utilized to collect the instantaneous shaft torque on occasion of engine start. In the third section, this paper has performed two experiments.

The traditional energy management algorithm is mainly based on a single driving cycle, it is obvious that many factors might be often neglected by designer, such as different driving cycles would suit for different control strategies. But they tend to make decisions on the balance of torque distribution and battery power that based on a single driving cycle. Therefore, it is very difficult to achieve the optimal control in each case. In this paper we introduce a new design concept of Multi-operating mode energy management, a mathematical model of the energy management applied to a hybrid vehicle system is presented. Results of simulations using the model with the Multi-operating mode energy management were compared with results of simulations using a model with the single mode energy management, allowing the energy efficiency evaluation of the proposed energy management system.

Embedded bus monitoring and fault diagnosis system, which was used on the hybrid vehicle was designed in this paper. And this system took the 32-bit embedded one as a hardware platform, customized a WinCE6.0 operation system and used EVC as the tool to design the embedded application. The functions of CAN communication, protocol defamations etc were realized. Good human-computer interaction is developed and the system has already been applied on the bus.

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.