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.     

Synthetic Control Strategy for a Car With Hydro-mechanical Continuously Variable Transmission System at Standing Start

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. The dynamic simulation model is established and integrated control strategy of standing start is proposed for dual mode CVT vehicle, aiming at automatic vehicle with torque converter as a starter and metal pushing belt as a higher transmission equipment (Dual mode CVT vehicle), on the base of engine and torque converter performance experiment. Simulation result shows that vehicle performance can be improved by using the control strategy proposed. The research results provide the theory method of analyzing and designing for CVT vehicle.     

Fuzzy Control Strategy and Simulation for ISG-Type Hybrid Electric Vehicles

Fuzzy control strategy is used to study the fuel economy of ISG-Type hybrid electric vehicle with CVT.Based on the instantaneous state of vehicle,the fuzzy logic controller is built aiming to get minimum fuel consumption.In order to avoid the subjective factor,the control rules are established with the optimized results from the sequence quadratic programming(SQP) method.Through the second development of ADVISOR,the simulation for ISG hybrid electric vehicle at different cycles has been accomplished.The results show that the fuzzy logic control strategy is efficient in improving the fuel economy of hybrid electric vehicle.     

纯电动车车用复合储能装置控制策略及参数优化

为解决目前纯电动车动力电池比功率不足的缺陷,对纯电动车的储能装置进行了研究。根据复合储能装置的特点和目的,制定了复合储能装置的工作模式,提出了基于速度与电流约束的模糊控制策略。为了进一步提高整车性能并降低蓄电池的输出电流,对复合储能装置的关键参数进行了线性优化,仿真结果表明:加装复合储能装置的纯电动车的加速时间缩短了12%,制动能量回收效率提高了39%,百公里耗电量减少了8.55%,并显著降低了蓄电池的输出电流,有效延长了蓄电池使用寿命和整车的续驶里程。     

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.     

搭载机电控制无级变速器混合动力汽车模式切换仿真分析

通过分析机电控制无级变速器(electrical-mechanical continuously variable transmission,EM-CVT)的结构特点,提出了搭载EM-CVT混合动力汽车的传动方案,建立了动力源数值模型、EM-CVT模型,分析了混合动力系统工作模式,并针对模式切换时的冲击问题,以减小冲击度为目标,通过分析典型工况下动力源输出转矩特性和各部件的动态特性,提出了基于发动机、ISG电机、自动离合器以及EM-CVT相互协调控制策略。利用MATLAB/SIMULINK仿真平台建立混合动力传动系统动力学模型,并对典型的模式切换过程进行了仿真分析。结果表明,所提出的控制策略能够有效控制混合动力传动系统在模式切换时产生的冲击,提高了混合动力汽车的驾驶舒适性。     

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.     

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.     

Simulation of The Torque Control System of Motor for Hybrid Vehicle

A strategy for induction motor control based on the grade of errors is developed to improve the performance of hybrid vehicle drive system. The stator flux error, electric magnetic torque error and flux position angle are used as control variables, and rules for the switching states are chosen according to the errors and the principle of the Direct Torquc Control. This strategy improves efficiently the electric magnetic torque response of the system. The result of simulation shows that this strategy is an ideal control strategy of hybrid vehicle, which can make the motor generate the electric magnetic torque efficiently, steadily and quickly.     

Application of Hydraulic Torque Converter Incorporated in Mechanical Continuously Variable Transmission

Continuously Variable Transmission which is the ideal transmission for automobile can improve dynamical and economical performance and reduce pollution emission effectively. Vehicle equipped with CVT where hydraulic torque converter is acted as start clutch have better acceleration performance and its starting control is very simple. Based on performance test of hydraulic torque converter and simulation on lock-up dynamic process of torque converter clutch, matching characteristic between engine and torque converter is evaluated , and the lock-up control rule of torque converter clutch and the control strategy of standing start of vehicle equipped with Continuously Variable Transmission with torque converter is proposed. By computer simulation on start process, vehicle equipped with CVT have better acceleration performance than equipped with five-speed MT.     

Multi-objective control strategy for parallel HEV using fuzzy logic

A fuzzy multi-objective control strategy is proposed for parallel hybrid electric vehicles (PHEV). By the concept of motor equivalent fuel consumption, the overall vehicle fuel economy and the corresponding emissions can be treated as the optimization objectives. Then a minimum average weighted deviation method is designed to find the Pareto optimal solution with considering the variations of objective preference in different district. The simulation on ADVISOR reveals that, compared with the rule based control strategy (RBCS), with the premise that there is no loss to power performance, the proposed fuzzy multi-objective control strategy (FMCS) not only improves fuel economy and emission level but also maintains battery SOC within its operation range more effectively.     

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     

Parameter Simulation on the Control Strategy for a Parallel Hybrid Electric Vehicle by CRUISE

The purpose of a parallel hybrid electric vehicle(PHEV) is for the best energy distribution between internal-combustion engine(ICE) and electric motor though the appropriate control strategy.It can not only keep the advantage of the ultra-low emission of electric vehicles(EV),but also take advantages of the hyperbaric energy of ICE.Simulation model for PHEV is built based on CRUISE,an auxiliary control strategy is designed,and then parameter simulation study on the control strategy is performed.The simulation results show that according to the different control requirements,the vehicle performance can be improved by adjusting!the corresponding control parameters.     

Ratio Control Principle and Mathematical Modal of Vehicle Traction Drive Type Continuously Variable Transmission

The traction drive continuously variable transmission is another kind of advanced transmission device for vehicle beside the metal pushing V_belt type CVT. It provides excellent driving performances including powerful driving capacity, high efficiency, good smoothness and economy, etc. The basic structure, transmission principle and the hydraulic servo control system of traction drive CVT are described. The mathematical model of the system is established. The study of this project provides the academic bases of further studying on the dynamic characteristics of CVT and vehicle.     

Efficiency Analysis of Steel Pushing V-belt Continuously Variable Transmission in Theory

The efficiency of the steel pushing V belt continuously variable transmission is an important factor for weighing CVT performance.Based on the mechanical analysis,by synthetically considering the effect of the viscosity lubricant on the power loss of CVT, the calculation formulae of efficiency have been found. The calculation simulationof efficiency is done, qetting two efficiency trend charts. One is efficiency with torque and rotational speed variation .The other is efficienccy with torque and ratio variation. The two charts have a guiding function in formulating matching and a control strategy and in an efficiency experiment.     

Analysis of Equilibrium Runing Lines of Engine and Hydraulic Torque Converter for a Vehiele with CVT

The mathematical model of the torque converters is established based on test results. Equilibrium running lines of engine and hydraulic torque converter are analyzed. The idea of matching and controlling is put forward for CVT vehicle with torque converter in starting ability, crawl ability and fuel economical efficiency, which lays a foundation for the exploitation of CVT vehicle with torque converter.     

Current Situation and Trend of the Traction CVT

In a toroidal CVT, power transmission is accomplished by means of a special traction oil that displays high shear resistance under a state of high pressure . A toroidal CVT can be used even with engines that generate large torque and provide excellent ratio change response and high efficiency . The history of research of the toroidal CVT are summarized and the toroidal CVT up to date is reported. The varieius aspects on the toroidal CVT are summarized ,including EHL theory , toroidal double cavity system,traction fluid ,ratio control system, traction drive system , efficiency analysis ,and so on. Finally ,The development of the toroidal CVT in the future is indicated.     

Dynamics Simulation of ISG-HEV Engine During Starting

The behavior of engine automatic starting and stop under idle speed is an important working model for HEV(hybrid electric vehicle), which can avoid engine running under idle speed. So it can reduce engine fuel consumption, exhaust gas emission and wear efficiently. The ISG(integral starter/generator) motor control strategy is given by dynamic research of the HEV engine starting, based on the model and simulation of resistant characters during engine starting, then an ISG motor-engine integral control model is built up and simulated. The result shows that the ISG motor can drive engine quickly and the simulation meets well with the need of starting time.     

The efficiency of a Ni MH battery used in hybrid vehicles

The efficiency of the 60QNY6.5 battery is studied by testing and theoretical analysis in order to improve the control precision of hybrid electric vehicles (HEVs) and the battery useful life. A rig for testing the Ni MH batteries of HEVs is established. The data from experiments performed on the Ni MH battery are analyzed. Based on the experimental results and the temperature of the batteries, internal resistance and electromotance models of Ni MH batteries are proposed by function fitting methods. The theoretic formula for battery efficiency is deduced by the operational principle of the battery and motor, which provides theoretical basis for dynamic optimizing technology of HEV system controlling strategy.     

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.