Model predictive control for a plug-in hybrid electric vehicle

The dynamic programming is applied to model predictive control configuration, and a predictive control mathematics model is established for the fuel economy of plug-in hybrid electric vehicles (HEVs) based on spatial-domain. A global optimal method for plug-in HEVs is studied with dynamic programming, and the results indicate that the state of charge (SOC) is reduced slowly from the maximum at a trip’s initiation to the low threshold at the destination. The theoretical SOC slope is proposed to be taken as the reference slope of model predictive control, and the theoretical reference contrail of SOC is modified according to the especial driving modes in future. The results show that the predictive control effect of this method is approached to the calculation result of global optimal and fuel consumption is obviously reduced.     

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     

design of a closed loop control virtual test for vehicle handling stability

In an effort to address the high risks and qualification demands of test drivers, a vehicle model and a driver model were built based on ADAMS/CAR, an advanced block of ADAMS. The steering efforts test procedure was designed according to the national standard GB/T 6223.5—1994. A virtual test was performed in ADAMS, and the results calculated. The results show that the driver model possesses a strong capacity to charge the vehicle model. The virtual test results satisfy the evaluation index, indicating the virtual test can be used to test and improve vehicle performance.     

Model predictive control strategy of a medium hybrid electric vehicle

The intense coupled and nonlinear behaviors were observed on the tall long span tower line systems which were under the icing and wind loads in heavy icing areas. A set of stiffness equations of insulator, conductor and boundary conditions was deduced. Taking the ±800 kV UHV DC transmission line from Xiangjiaba to Shanghai as an example, the simplified numerical model of transmission tower, conductor, insulator and constraint was developed. The long span transmission tower line system models under seven loads conditions were analyzed by static nonlinear methods. It was found that the P Δ effect of tower components was small when the covered ice was uniformly distributed. The unbalanced wire loads on the tower would lead to twist effect when the covered ice was uneven distributed. The axial forces, moments at restraint nodes and the longest cantilever member were greatly affected by the P Δ effect, under which the unfavorable effect on the structure should be considered.     

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。     

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.     

插电式混合动力汽车能量管理策略研究现状和发展趋势

目前国内外学者对插电式混合动力汽车能量管理策略进行了较为广泛和深入的研究,取得了良好的节能减排效果,为进一步提升其性能,有必要对插电式混合动力汽车能量管理策略的研究现状进行总结并对其发展趋势进行分析。首先对插电式混合动力汽车动力源能量流分配方法进行了归纳和分析,指出了当前插电式混合动力汽车能量管理策略两个亟待解决的问题：未考虑发动机冷却液温度和三元催化器温度等温度因素对油耗和排放影响;当前插电式混合动力汽车能量管理策略是以行驶功率需求作为输入,忽略了驾驶室制冷/供暖功率需求。最后提出了计及发动机冷却液温度和三元催化器温度等温度因素的能量管理策略和计及驾驶室制冷/供暖功率需求的能量管理策略两个未来研究方向。     

Development of the remote data supervisory system of the hybrid electric vehicle

Taking the hybrid electric vehicle as the investigation subject, this paper studies the remote data acquisition, supervisory control and redisplay system of the hybrid electric vehicle fault diagnosis. The system gathers the simulate CAN BUS data through serial ports by the data acquisition device and send data to the remote web servers by the GPRS wireless communication module. For the demands and features, the paper makes the module selection and design the hardware of lower computer ,and the software on the host computer and lower computer. It takes several notebooks as the simulate vehicle date emission source to make an experiment, achieving the function of wireless data transfer, data acquisition, supervisory, redisplay for multi hybrid electric vehicles at the same time, and protocol setting up. Especially the function of wireless data transfer and protocol setting up, make a big progress on the common use and convenience of fault diagnosis system.     

Coordinated torque control strategy for driving-mode-switch of strong hybrid electric vehicle

For a new type of strongly hybridized system, the vehicle ride performance is used as the study goal, a coordinated control strategy is put forward to suppress the torque surge after the analysis of the parameters changes of engine, motor, clutch and transmission during the driving-mode-switch process. The strongly hybridized vehicle simulation model is developed based on the coordinated control strategy. The typical drive mode switching process performance simulation and analysis are performed. The results show that introducing the coordinated control strategy reduces the torque surge during the driving-mode-switch process and improves the vehicle drivability.     

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.     

A fault data recording system design for hybrid electric vehicles

A data recording system for fault diagnosis of hybrid electric vehicles was studied by taking the integrated starter and generator (ISG) hybrid electric vehicle as the investigation object. The fault diagnosis communication net was established using a CAN bus and a K line. As designed, the system hardware structure included a CPU processing module, a communication module, and a USB recording module. With the system requirements and characteristics in mind, special circuit design and analysis of USB mass storage module were carried out based on the hardware scheme and software design. In the running test, the fault data recording system worked stably, and the data was recorded integrally and correctly. At the same time, the online display data accurately reflected the vehicle's running status.     

Application for Hybrid Electric Vehicle Based on CAN Bus

The paper introduces the application of CAN bus in the Hybrid Electric Vehicle, studies the CAN bus technique and the design based on the node of CAN bus, and provides a network topology mode. The theories foundation and basis for new generation automotive are provided, which are combined to introduce the hardware constitutes and software method for the node of CAN bus.     

Study on global optimization control strategy of ISG velocity coupling hybrid electric vehicle

Hybrid system has the advantage of energy conservation and environmental protection. To improve the fuel economy of a hybrid system,based on the structure of the ISG velocity coupling HEV(hybrid electric vehicle),a dynamics simulation model is built. By using dynamic programming(DP) global optimization method,the variables of the engine throttle and the motor torque are set as the control variables,and the engine speed and the battery SOC are set as the state variables,the engine fuel economy is set as the objective function,and the battery SOC balance and the limited frequent shifting are set as the additional cost function. Then a global optimization program is built,and the simulation results indicate that the fuel economy of DP control HEV is 35.5% more efficient than that of the conventional vehicle.     

The cooling structure of Ni MH batteries in hybrid electric vehicles

Focusing on Ni MH batteries used in hybrid electric vehicles (HEV), a simulation analysis of the flow and temperature fields of the cooling structure in existing batteries is carried out using computational fluid dynamics software. The results show that the temperature uniformity is poor. The uniformity of the flow and the temperature fields is improved by adjusting the baffle and battery positions, changing the tilt angle and the distance between the batteries, inserting wind plates and a coating insulation layer. The coating insulation layer achieves the best effect. Further simulation shows that the coating insulation layer method has the best effects. The results provide the design basis for thermal management program of Ni MH batteries in HEV.     

Development of control strategy for a series parallel hybrid electric bus based engine efficiency optimization

To improve efficiency of engines,according to the characters of a novel series parallel hybrid electric bus(SPHEB) to define the operation area of ice,a kind of power balancing control strategy is adopted and the battery power is used as a variable to optimize the efficiency of fuel converter,and the PI control is implemented to control the SOC balance. To validate the proposed strategy’s effectiveness and reasonableness,a forward model is built based on simulink and the simulation results demonstrate that the proposed strategy can successfully improve the efficiency of fuel economy up to 6.74% compared with that of equivalent fuel minimum control strategy,while the battery SOC is also limited in the desired range.     

The main loop and servo loop structure control strategy of ESC

Aiming at the control of electronic stability control system(ESC)which can enhance the handling stability in limited condition,the hierarchical control structure control strategy of ESC including main loop and servo loop is proposed. The first order sliding mode control is used in the main loop and the sliding mode plane and control law are designed. The output of main loop is the accessional yaw moment. The nine points with five states control which can approximately simulate human thinking is used in the servo loop. The brake pressure is controlled by the servo loop aiming at the desired slip rate and the accessional yaw moment is generated by brake force. The driver in the loop simulation bench is designed and the online test of the control strategy is carried on. The test results indicate that the handling stability and active safety are enhanced remarkably by the ESC control strategy in the drive condition of low adhesion road and driver handling vehicles immoderately,and the testing facticity and the pertinency of developed control strategy are improved by the driver in the loop simulation.     

Design and development of propulsion system for CNG-electric hybrid city-bus

The design of propulsion system for CNG-electric hybrid city-bus is introduced based on the selection of driving cycle and the establishment of control strategy. Making program of powertrain’s configuration is included as well as parameters’ selection and matching of components such as engine, motor, battery and transmission. The simulation results show that the design meets the requirements. The components of the propulsion system are integrated together, and then they are installed into the sample city-bus. The roadway test has been done under the target driving cycle. Compared with the peer CNG city-bus, there are 28% increasing in the largest climb degree and the acceleration time of 0~50 km is reduced more than 1.8 s, and the fuel saving rate achieves to 22% under the typical city-bus driving cycle of China.     

Research on Current Situation and Trend of Control Strategies for Hybrid Electric Vehicles

The vehicle's driving performances is determined by the control strategies and constructions of hybrid electric vehicles (HEV). The constructions of HEV are classified according to the change of state of charge of battery pack, and a study on current situation and trend of control strategies for HEV is presented in this paper. The research indicated that the current control strategies for HEV are not perfect and need further optimization. The control strategies should realize the optimum match among engine, motor, battery and transmission according to the characteristics of each component and vehicle's driving conditions. Many aspects including the fuel economy, emission, the life of battery pack, drivability, the reliability of each component and HEV's manufacture cost should be considered in the control strategies. A study on the control strategies and its optimization that take account of the aspects mentioned above is a work emphasis in the future. This paper also points out the PHEV equipped with small motor, small engine and continuously variable transmission is an ideal system construction for getting optimal fuel economy, lower emissions, steady drivability, lower manufacture cost and HEV's mass.     

Optimal shift decision of automated manual transmission for hybrid electric transit bus

Most HEBs with AMT adopt the traditional single or two parameter shift schedule,however,HEB is very different from traditional bus,this approach cannot make full use of the advantage of hybrid. In order to obtain the optimal fuel economy,emission and low shift frequency, an objective functional is established for hybrid electric bus based on simplified models of hybrid system,and a new solving algorithm based on dynamic programming (DP)is also presented. In the end,the best shift decision points in Chinese typical urban transit bus driving-cycle are obtained. After comparison between the traditional two parameter shift schedule and the shift decision based on DP,it’s proved that the best shift decision points can improve the fuel economy of the HEB obviously through simulation and road test under Chinese typical urban transit bus driving-cycle,and the number of gear shift is also obviously reduced.