| Regenerative braking (energy recovery braking) is one of key advantages of HEV, which has a direct impact on fuel economy, emission and vehicle security. When HEV is braking, regenerative braking system will make the motor become a generator for generating electricity through the power train system and supplying the whole braking forces or partial braking forces at the same time. Finally, electric energy is saved into the battery pack. Regenerative braking not only realizes the braking and deceleration, but also recovers the kinetic energy. So the regenerative braking is an effective measure to improve the hybrid vehicle fuel economy and reduce emissions effective measures.The brake force of the HEV constitutes of the regenerative brake force and the friction brake force. There are variety braking modes in the braking process, which has the problem how to integrated control the regenerative braking and the friction braking .So the brake system of HEV is much different from the conventional vehicles. Through the Coordinated Control the pressure of the front-wheel and vehicle braking force distribution, achieving the safety brake and efficient energy recovery .By identifying a reasonable distribution strategy of the brake force, the hybrid vehicle can more efficiency recovery the energy of brake under the security conditions. So how to achieve the coordinate control the regenerative braking and the friction brake become to the key technology of the regenerative Braking.Based on the developed of the hybrid vehicle braking systems, which commonly used the electro-hydraulic proportional valve to achieve the coordinate control the pressure of the front-wheel in the process of regenerative brake, which requires the transformation of the traditional braking system or even larger re-design. The main content of this paper is how to make use of the ABS brake system to achieve coordinate control the pressure,this problem is still In the exploration stage.Focus on CVT Hybrid Electric Vehicle with ISG, and based on the deeply theoretical researching, this paper has study on the integrated strategy and methods control of the regenerative braking and the friction braking. The main results include:1. Based on the analysis the braking mode, control strategies and braking performance of the HEV, design a new integrated braking system, then selected the layout form of ABS in the HEV.2. According to bench experiment data, combined with numeric modeling and theory modeling, simulation model for regenerative braking system of hybrid electric vehicle is built, including system parts(engine,ISG motor,NiMH battery), transmission parts(clutch,CVT and differential) and dynamic model.3. Based on the analysis of the ABS system, with the PID control method, established the model of high-speed switching valve, the simulation results showed that use of PID control method obtained a very good track pressure response characteristics4. Based on the hardware of the ABS system, established the fuzzy controller about the integrated control the regenerative braking and the friction braking. The controller including a slip rate fuzzy controller and the dynamic torque distribution fuzzy controller.Slip rate fuzzy controller used to control the wheel slip to make the wheels slip rate stabilize in the optimal rate of slip, and the dynamic torque distribution fuzzy controller used to determine the allocation of energy recovery torque and hydraulic brake torque dynamic distribution. Under the safety braking conditions, the hybrid electric vehicle implement the efficient energy recovery.5. With the MATLAB/Simulink simulation software, established CVT hybrid vehicle simulation model, which are simulated under the typical braking modes, the simulation results show that the controller has good effects to coordinate the brake force between the regenerative brake and the friction brake also show that the controller have a great application value.
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