Papers by Author: Chao Yu

Abstract: In order to adjust the working points of the engine for a full hybrid bus, this paper proposed a set of optimization control method. In speed adjustment process, the rate of change was optimized and limited to avoid rapid and frequent change along with power required by the driver. Allow for complex engine model, fuzzy control method was introduced to regulate the torque response rate. Furthermore, dynamic amplitude upper and lower bound were limited to prevent system overshoot and oscillation. Nowadays, there are hundreds of busses operates in several public transport lines. Vast statistic data and experimental results verify the feasibility and effectiveness of the proposed control method in this paper. The vehicle has good fuel economy compared to the counterpart one, and the dynamic performance is also greatly improved.

Abstract: A new type power steering system was developed for electric hybrid city bus. It is mainly composed of fluid reservoir, electric motor, steering pump, safety valve, solenoid, pressure sensor, hydraulic cylinder, braking air tank, controller, steering wheel, steering angle sensor, steering control valve, mechanical steering mechanism, steering power cylinder. Its main idea is based on using of pressure from braking air tank to push a cylinder to generate hydraulic pressure. It can provide enough pressure for steering needing timely. And the steering pump does not need working at the time of no steering requirement. The application of a new type power steering system can save energy to improve fuel efficiency.

Abstract: A new hybrid power train using variable displacement pump/motor was developed for electric vehicle. It mainly includes engine, brake, clutch, variable displacement pump/motor, hydraulic accumulator, output gear, planetary gear set, controller. The planetary gear set, brake, clutch, output gear, power output shaft are integrated to form power split and coupling mechanism. In this new power train, the hydraulic variable displacement pump/motor is used instead of the electric generator/motor with different operation modes, which are pure hydraulic motor driving, pure engine driving, parallel hybrid driving, and compound hybrid driving.

Abstract: A new type test bench was developed for power train used in electric hybrid vehicle. This bench was mainly composed of inertial flywheels, brake, clutch, dynameters, and controller. When testing the power train, the engine, power train, inertial flywheels, brake, clutch and dynameters are connected in series. One end of inertial flywheels is connected with output end of power train; the other end is connected with a clutch. Between the inertial flywheels and clutch, there is a brake for braking of flywheels. The clutch is for connection and disconnection of inertial flywheels and dynameters. This new test bench can perform different power modes with corresponding operation modes set in the main controller.

Abstract: A new kind of power train was developed for electric hybrid vehicle, which is mainly consisted of engine, two generator/motors, two sets of planetary gear, power mode selection mechanism. The power mode selection mechanism has three positions, it make the power train have three different operation modes which are pure electric driving mode, pure engine driving mode and hybrid driving mode. Different operation mode is corresponding to different vehicle load conditions for economy and dynamics requirements.

Abstract: A new type hybrid power train system was developed for HEV, which can works as power coupling and transmission mechanism with three input shafts, one output shaft and fixed transmission ratios. The HEV adopting this new device can realize three operation modes: hybrid power driving mode, pure electric propulsion mode and electricity generation mode at vehicle stop condition. It can make engine work at optimum fuel consumption area, utilize motor to provide high start torque and realize modes conversion transform at probable rotation speed. The whole structure of this system is simple and easy manufactured, which can meet vehicle driving requirements at complicated conditions.

Abstract: The pure electric vehicles and hybrid electric vehicles are being developed and used wildly to save energy and reduce air pollution. In pure electric vehicles and hybrid electric vehicles, most of the steering hydraulic pump and braking sir pump have one electric motor to drive its pump. A new system with one electric motor for these two bumps was developed for application in pure electric vehicles（EVs） and hybrid electric vehicle ( HEVs). Comparison with conventional configuration, this new method can reduce cost and mounting space with compact size and higher energy efficiency. And the test results show that the new system can meet the requirements of HEV operation quite well.

Abstract: In pure electric vehicle and hybrid electric vehicle, the adoption of motor barking for energy recycling make its braking control more complicated. Making good use of braking energy can improve vehicle efficiency. A new method was developed to coordinate the motor regenerative braking and ABS braking. Which identify the road condition with real time basing on wheel speed information from four wheel speed sensors. Then control system decides the braking force provided by ABS system. The residual braking force is produced by motor barking to meet total braking force requirements. The two braking forces are coordinated by control system to perform brake function of vehicle.

Abstract: Abstract: the FEM model of unitary body of HEV city bus was established, and the model accuracy was proved by electric measurement. The Sensitivity analysis of stiffness was conducted to determine variables for optimization design basing on special analysis software tools. At last, the plan was formed to reach design target of light weight with least stiffness change and regulated strength of vehicle body.