Control strategy of regenerative braking for hybrid electric vehicle based on engine braking

Focusing on a continuously variable transmission(CVT) hybrid electric vehicle with integrate starter generator(ISG), modeling and simulating of engine braking was conducted. An optical control strategy of regenerative braking was put forward. When there is no regenerative braking, engine brake force can be used effectively by changing the CVT ratio to reduce the braking force requirements for wheel brakes based on the calculated results of engine braking. When there is regenerative braking, the braking priority sequence is generator braking, engine braking, and finally frictional braking. A forward simulation model for regenerative braking system of hybrid electric vehicle was built. The simulation and analysis under typical driving cycles was conducted. The result shows the control strategy and the models are reasonable and feasible.     

Simulation analysis on braking system of hybrid vehicle with ISG

A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.     

Simulation of regulatory driving cycle for motorcycle on the engine test bench

Dynamic performance test methods and experiments of motorcycle engine are investigated. The models of clutch, transmission and brake are simulated by changing the resistance torque imposed by the dynamometer to the engine and with the moment of inertia and road resistance data, the model of a 125 mL motorcycle is established on the dynamic engine test bench. On this basis, the road tests are simulated with models of different inertial mass. Compared with the experiments on the drum tester, the results show that when the inertial mass is set to 1.1 times the datum mass of the motorcycle, the deviations of its maximum speed, sliding distance and acceleration time are no more than 3% and the fuel consumption of 100 km is no more than 5% except the speed of 35 km/h. Through driver operational model, the effect of different gear change models on vehicle acceleration performance is studied. Finally, the regulatory driving cycle for motorcycle is implemented on the dynamic bench and the measurements show that it has high ability to accurately control speed.     

Vehicle stability control system design using optimal allocation of yaw moment

In order to improve vehicle handling stability,a control system using optimal allocation of yaw moment was designed.The first layer is a linear quadratic regulator (LQR) controller,which optimizes a desired yaw moment to work on the vehicle and calculates reference wheel slip for the target wheel.The second layer of the control system is a PID controller which can track the reference wheel slip rate,and then apply braking torque on the target wheel to make the vehicle stable.Simulations are carried out by using an 8-dof nonlinear vehicle model under different conditions.The simulation results indicate that the designed control system can effectively improve vehicle handling stability.     

Vehicle Lateral Stability Control Based on Sliding Model Control

In view of the vehicle cornering or path changing under ultimate handling maneuver, a 3-DOF nonlinear vehicle dynamics model which takes the vehicle lateral velocity, yaw rate and body roll angle as the State variables is presented. Based on the dynamic analysis, the method which using additional yaw moment produced by different longitudinal braking force among each wheels to improving vehicle handling stability in emergency situations is discussed. Considering the sideslip angle as one of the vehicle state variables is difficult to measuring, the sideslip angle estimation based on vehicle dynamic model and kinematics is designed. And then, based on the theory of siding model control, the combining sliding model control system is founded, which taking the vehicle yaw rate and body side-slip angle errors between the estimated and the real as the input variables, and taking the braking torque and the steering angle as control aims. The simulation results indicate that the control method can effectively improve the vehicle lateral handling stability.     

Research and development of a testing control system for a heavy duty vehicle automatic mechanical transmission test bench

Automatic mechanical transmissions (AMT) are suitable for use in heavy duty vehicles. Bench testing is an important task of the research and development. Many objectives, such as AMT performance testing, matching AMTs with engines, and optimizing control rules, can be achieved through bench testing, thereby laying a foundation for AMT application. An AMT testing bench is built up based on a developed AMT. By analyzing the performance requirements of AMT bench testing for heavy duty vehicles, a testing controlling system scheme is proposed and methods of data acquisition and communication are analyzed. Control methods for actuators are proposed based on analyzing the characteristics of AMT actuators. A testing control program for AMT bench testing is developed based on the Delphi platform. The entire bench testing system possesses advances test functions.     

Development and Design of ABS Dynamic Test-bed for Automobile

Aiming at the problems of ABS products tested on vehicle, a character test-bed of automobile and motorcycle ABS is studied.To provide an economic and efficient test method for vehicle anti-lock braking system(ABS) in laboratory,the idea of designing a dynamic test-bed is researched and developed,which can simulate actual working status of automobiles well and truly.The test-bed structure character,design principle and key techniques are discussed.It will provide a new method for testing ABS products of automobile and motorcycle.     

插电式混合动力汽车纯电动行进间启动发动机的平顺性控制

针对单电机插电式混合动力汽车在纯电动行进间电动机启动发动机时由于系统输出转矩变化进而引起整车冲击的问题,分析得到发动机点火时刻的不同及离合器接合状态的不同是造成转矩波动的原因。在此基础上,提出了基于离合器主、从动盘转速差和电机角加速度为输入量的离合器压力模糊控制的混合动力汽车模式切换动态协调控制策略,并对比了发动机目标转速点火和怠速转速点火的控制效果。最后通过台架试验以及实车道路试验对提出的控制策略进行了验证。结果表明,基于目标转速点火的协调控制策略能减小整车的冲击度。     

Development and Investigation on Duty Valve Drived Hydraulic Brake Servo System

A duty valve drove hydraulic brake servo system of HEV(hybrid electric vehicle) power transmission test rig is studied.The brake performance depends on the responses of the pressure control.A PI controller is designed through analyzing the working characterizes of the hydraulic brake system and duty valve by using rapid control prototype(RCP) tool-dSPACE,all the model and control code are successfully download to the AutoBox,and rapid control prototype experiment shows that the benefits of developing duty valve drove hydraulic brake servo system with good performance has been achieved.     

Simulation and verification experiment of thepneumatic brake LSPV based on AMESim

Based on the analysis of dynamics method of pneumatic transmission, the mathematic model of air brake Load Sensing Proportional Valve (LSPV) is established by fluid servo control theory. The air brake LSPV of one All Terrain Vehicle (ATV) is simulated with the platform of advanced modeling ervironment for performing simulations of engineering system(AMESim), then the input and output pressure characteristic curve of the valves are obtained. The characteristic curve shows, with the load increasing, the pressure adjustment point of Load Sensing Proportional Valve (LSPV) moves up. When the pressure reaches into the pressure adjustment point, the increase rate of output pressure is less than the increase rate of input pressure, so that it can effectively prevent the lockup of the rear wheel precede the front wheel. The result of the simulation is consistent with the experiment result. The validity of the model is verified, which provide foundation for the simulation of the air brake elements and brake system.     

Automobile anti lock braking system control based on a least squares support vector machine

Using the referenced slip rate and angle acceleration of the wheel as input vectors and the braking pressure as an output vector, an automobile anti lock braking system (ABS) controller based on a least squares support vector machine (LS SVM) was designed. Training the LS SVM controller using the supporting vector, the parameter of the controller was calculated. An anti lock braking system was designed that includes an input layer, a control layer, and an output layer. Using wheel speed as an input, the braking pressure of each wheel was calculated. The pulse width modulation (PWM) method was used to control the braking pressure, and thereby to bring ABS control. An automotive ABS test and control system was constructed. Road tests under different conditions were completed according to international standards. Test results show that an anti lock braking control method based on LS SVM has good braking stability and adaptability. It is an effective new ABS control method.     

Hardware-in-loop Simulation on Regenerative Braking for Hybrid Electric Powertrain with ISG

Regenerative braking is one of main performance modes, which can reduce fuel consumption and emission. A dynamics braking control model is built for hybrid electric vehicle with ISG, an off-line simulation is completed. A regenerative braking rig in dSPACE environment is built on the hybrid electric powertrain. The tests and analyses for different speed, deceleration shift and clutch state is completed in a Hardware-In-Loop simulation, which lays a foundation for the optimization of regenerative braking control strategy for HEV.     

Development and application of continuouslyvariable transmission test facilities

Basic structure and speed control principles of rubber V belt continuously variable transmissions (CVT) are analyzed. A test bench on which the governing characteristics, carrying capacity, pulley diameters, and transmission efficiency of CVTs can be tested is developed. This test rig permits the measurement of speed, torque and axial displacements of moveable flanges. The experiment not only verifies the results of the theoretical analysis but also reveals the trend of governing characteristics and efficiency affected by the operating condition changes. These conditions include the speed ratio, rotational speed, and external load. Based on this investigation, a method for improving CVT efficiency is proposed. The feasibility of the test bench is demonstrated by the experiment, which has a guiding role for design and parameter matching of CVTs.     

Study and Simulation on Control Strategy for CVT Ratio in HEV when Regenerative Braking

In order to satisfy the safety of vehicle braking and the fuel economy,a control strategy for regenerative braking force distribution is proposed by considering of battery SOC and braking severity.In addition,a CVT speed ratio control strategy is proposed to operate the motor in the high efficiency area to improve motor generating efficiency.A simulation model of mild hybrid electric vehicle is set up.Simulation result on ECE+EUDC typical driving cycles show that the effectively regenerating energy of braking of hybrid vehicle with CVT is lager than that of hybrid vehicle with MT by 2.5%.     

Handling performace evaluation of a vehicle stability control system based on a driver model

By combining a driver model, a vehicle system dynamics model, and a vehicle lateral stability control system, the performance of the driver vehicle road closed loop system through a pylon course slalom test was simulated. The simulation was done in accordance with the GB/T6323.1-94 standard. Vehicle stability control system effectiveness was evaluated by measuring the mean maximum yaw rate and the mean maximum steering wheel angle. The simulation results showed the slalom test value with lateral stability control was approximately 4% higher than without a stability control system. This indicates the controlling system improves vehicle handling stability.     

Design of data acquisition and communication system for AMTcomprehensive performance test bench

AMT (Automatic Manual Transmission) comprehensive performance test is one of the main means to develop and evaluate AMT. An overall scheme of the data acquisition and communication system for AMT comprehensive performance test bench is proposed according to the requirement of the test bench, and a communication network of data acquisition and communication system is built. The hardware and software of data acquisition system are designed. The experiments show that the system meets the requirement of data acquisition and communication system for AMT comprehensive performance test bench and it lays a foundation for AMT comprehensive test research.     

Development of General Measurement & Control Software Platform for Automobile Components Test

This paper has discussed the characteristics of the development of automobile components test system.Based on the development example of vehicle hyraulic shock absorber test system,the paper has built general measurement & control software platform for automobile components tests,carved up main function modules along with the class libraries for platform,and adopts multi-thread technology to guarantee platform's real-time performance.The platform has enough flexible and extensible capability,and can satisfy the requirements of software developing for modern automobile components test system.     

Coordinated pressure control of a regenerative braking system based on a hybrid electric vehicle with an integrated startor and generator

With a focus on a Changan hybrid electric vehicle (HEV) with an integrated startor and generator (ISG), strategies for braking force distribution and coordinated pressure control are put forward, and a dynamic braking control model is constructed for off     

Technologies of Intelligent Vehicle in Intelligent Transportation System (ITS)

Intelligent Transportation System (ITS) is the most effective method to solve the modern traffic problems. Intelligent vehicle plays a very important role on ITS, and it influences the success of ITS directly. Intelligent Transportation System (ITS) is briefly introduced. Then it is given that advanced vehicle control system and electrics stability program (ESP) in the key technology of intelligent transportation system. The control algorithm for vehicle movement is discussed and the test result is given.     

Integrated Control Strategy for Dual State Continuously Variable Transmission System

Continuously variable transmission (CVT) is the ideal transmission for automobile, it is also one of the most important research items of researchers and automobile companies all over the world. In order to research vehicle with torque converter as starter and metal pushing belt as high speed transmission equipment(dual state CVT system), based on the test data of engine and torque converter, the integrated control strategy for vehicle with dual state CVT system is proposed and integrated control simulation for car with dual state CVT system is finished at the condition of multi mode. The research results provide the theory method of analysing and designing for CVT vehicle.