Regenerative braking was the process of converting the kinetic energy and potential energy, which were stored in the vehicle body when vehicle braked or went downhill, into electrical energy and storing it into batter...Regenerative braking was the process of converting the kinetic energy and potential energy, which were stored in the vehicle body when vehicle braked or went downhill, into electrical energy and storing it into battery. The problem on how to distribute braking forces of front wheel and rear wheel for electric vehicles with four-wheel drive was more complex than that for electric vehicles with front-wheel drive or rear-wheel drive. In this work, the frictional braking forces distribution curve of front wheel and rear wheel is determined by optimizing the braking force distribution curve of hydraulic proportional-adjustable valve, and then the safety brake range is obtained correspondingly. A new braking force distribution strategy based on regenerative braking strength continuity is proposed to solve the braking force distribution problem for electric vehicles with four-wheel drive. Highway fuel economy test(HWFET) driving condition is used to provide the speed signals, the braking force equations of front wheel and rear wheel are expressed with linear equations. The feasibility, effectiveness, and practicality of the new braking force distribution strategy based on regenerative braking strength continuity are verified by regenerative braking strength simulation curve and braking force distribution simulation curves of front wheel and rear wheel. The proposed strategy is simple in structure, easy to be implemented and worthy being spread.展开更多
The paper presents physical and mathematical models of kinetic system, drive system （electric and combustion traction motors）, and also wheel and rails traction vehicle supply system （car, special vehicle, modern t...The paper presents physical and mathematical models of kinetic system, drive system （electric and combustion traction motors）, and also wheel and rails traction vehicle supply system （car, special vehicle, modern tram vehicle）. Selected predictive and quasi dynamic control system algorithms of traction vehicle are presented in the paper. For selected constructions of traction vehicle drive system are presented in simulation models and are results of calculations of different exploitations work state of wheel vehicle with hybrid drive system. Results of computer calculations are verified with laboratory measurement and suitable corrections coefficient to simulations models of vehicles is introduced.展开更多
This paper explores the potential meanings of battery electric vehicles （battery EVs）. Relevant ideas were collated through facilitated exchange of explicated and tacit knowledge, realized by individual essay prepar...This paper explores the potential meanings of battery electric vehicles （battery EVs）. Relevant ideas were collated through facilitated exchange of explicated and tacit knowledge, realized by individual essay preparation and a facilitated seminar workshop. Additional classifications and clustering by the author led to the following principal results： the EV as a power source and buffer forms the foundation for most meanings beyond transport. EVs can act both in the context of＂shelters＂ for individuals as well as ＂community vehicles＂ with a focus on, e.g., local renewable energy production integration. Reduced to a simple product, EVs can also be designed to make sense in developing country environments. However, many ＂intelligent＂ features associated to EVs are available also for combustion engine vehicles and thus provide only necessary, but not unique added value to EVs. Concluding, EVs will take over market share from internal combustion vehicles only if they satisfy human needs beyond mobility.展开更多
The demand for short term energy storage providing high power for electric and hybrid-electric vehicles is increasing drastically. Stationary FESS （flywheel energy storage systems） is established as UPS （uninterrup...The demand for short term energy storage providing high power for electric and hybrid-electric vehicles is increasing drastically. Stationary FESS （flywheel energy storage systems） is established as UPS （uninterruptible power supply） and represent an emerging market. In contrast, mobile FESSs are currently only used in a few application, e.g., in motor sports. To enable a wider use in personal and public transportation the life-span of the flywheel＇s bearings needs to be increased significantly. This paper presents an alternative approach to extend the lifespan of the flywheel＇s bearings significantly by using a CREAMB （combination of rolling element and active magnetic bearings）.展开更多
As an alternative power source for hybrid electrical vehicle(HEV), electric generating system(EGS) driven by sphere cam engine(SCE) is said to own higher power density and integration. In this work, the structure and ...As an alternative power source for hybrid electrical vehicle(HEV), electric generating system(EGS) driven by sphere cam engine(SCE) is said to own higher power density and integration. In this work, the structure and working principle of EGS were introduced, based on which the advantages of EGS were displayed. The profile of sphere cam was achieved after the desired motion of piston was given. After establishing the dynamic model of power transmission mechanism, the characteristics of cam-roller mechanism were studied. The results show that the optimal cam profile of SCE is a sinusoid curve which has two peaks and two valleys and a mean pressure angle of 47.19°. Because of the special cam shape, the trace of end surface center of piston is an eight-shape curve on a specific sphere surface. SCE running at speed of 3000 r/min can generate the power of 33.81 kW, which could satisfy the need of HEVs. However, the force between cylinder and piston skirt caused by Coriolis acceleration can reach up to 1182 N, which leads to serious wear between cylinder liner and piston skirt and may shorten the lifespan of SCE.展开更多
Based on the multidiscipline design optimization theory, a multidiscipline collaborative optimization model of the differential steering system of electric vehicle with motorized wheels is built, with the steering eco...Based on the multidiscipline design optimization theory, a multidiscipline collaborative optimization model of the differential steering system of electric vehicle with motorized wheels is built, with the steering economy as the main system and the steering road feel, the steering flexibility and the mechanic character of the steering sensors as the subsystems. Considering the coupled relationship of each discipline, the main system is optimized by the multi-island algorithm and the subsystems are optimized by the sequential quadratic programming algorithm. The simulation results show that the steering economy can be optimized by the collaborative optimization, and that the system can get good steering road feel, good steering flexibility and good mechanic character of the steering sensors.展开更多
The model of the differential steering system(DSS) of electric vehicle with motorized wheels and the three-degree-of-freedom dynamic model of vehicle are built.Based on these models,the concepts and quantitative expre...The model of the differential steering system(DSS) of electric vehicle with motorized wheels and the three-degree-of-freedom dynamic model of vehicle are built.Based on these models,the concepts and quantitative expressions of steering road feel,steering portability and steering stability are proposed.Through integrating the Monte Carlo descriptive sampling,elitist non-dominated sorting genetic algorithm(NSGA-II) and Taguchi robust design method,the system parameters are optimized with steering road feel and steering portability as optimization targets,and steering stability and steering portability as constraints.The simulation results show that the system optimized based on quality engineering can improve the steering road feel,guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the electric vehicle with motorized wheels system.展开更多
基金Project(JS-102)supported by the National Key Science and Technological Program of China for Electric VehiclesProject supported by Jilin University "985 Project" Engineering Bionic Technology Innovation Platform,China
文摘Regenerative braking was the process of converting the kinetic energy and potential energy, which were stored in the vehicle body when vehicle braked or went downhill, into electrical energy and storing it into battery. The problem on how to distribute braking forces of front wheel and rear wheel for electric vehicles with four-wheel drive was more complex than that for electric vehicles with front-wheel drive or rear-wheel drive. In this work, the frictional braking forces distribution curve of front wheel and rear wheel is determined by optimizing the braking force distribution curve of hydraulic proportional-adjustable valve, and then the safety brake range is obtained correspondingly. A new braking force distribution strategy based on regenerative braking strength continuity is proposed to solve the braking force distribution problem for electric vehicles with four-wheel drive. Highway fuel economy test(HWFET) driving condition is used to provide the speed signals, the braking force equations of front wheel and rear wheel are expressed with linear equations. The feasibility, effectiveness, and practicality of the new braking force distribution strategy based on regenerative braking strength continuity are verified by regenerative braking strength simulation curve and braking force distribution simulation curves of front wheel and rear wheel. The proposed strategy is simple in structure, easy to be implemented and worthy being spread.
文摘The paper presents physical and mathematical models of kinetic system, drive system （electric and combustion traction motors）, and also wheel and rails traction vehicle supply system （car, special vehicle, modern tram vehicle）. Selected predictive and quasi dynamic control system algorithms of traction vehicle are presented in the paper. For selected constructions of traction vehicle drive system are presented in simulation models and are results of calculations of different exploitations work state of wheel vehicle with hybrid drive system. Results of computer calculations are verified with laboratory measurement and suitable corrections coefficient to simulations models of vehicles is introduced.
文摘This paper explores the potential meanings of battery electric vehicles （battery EVs）. Relevant ideas were collated through facilitated exchange of explicated and tacit knowledge, realized by individual essay preparation and a facilitated seminar workshop. Additional classifications and clustering by the author led to the following principal results： the EV as a power source and buffer forms the foundation for most meanings beyond transport. EVs can act both in the context of＂shelters＂ for individuals as well as ＂community vehicles＂ with a focus on, e.g., local renewable energy production integration. Reduced to a simple product, EVs can also be designed to make sense in developing country environments. However, many ＂intelligent＂ features associated to EVs are available also for combustion engine vehicles and thus provide only necessary, but not unique added value to EVs. Concluding, EVs will take over market share from internal combustion vehicles only if they satisfy human needs beyond mobility.
文摘The demand for short term energy storage providing high power for electric and hybrid-electric vehicles is increasing drastically. Stationary FESS （flywheel energy storage systems） is established as UPS （uninterruptible power supply） and represent an emerging market. In contrast, mobile FESSs are currently only used in a few application, e.g., in motor sports. To enable a wider use in personal and public transportation the life-span of the flywheel＇s bearings needs to be increased significantly. This paper presents an alternative approach to extend the lifespan of the flywheel＇s bearings significantly by using a CREAMB （combination of rolling element and active magnetic bearings）.
基金Projects(51475464,51175500,51575519)supported by the National Natural Science Foundation of China
文摘As an alternative power source for hybrid electrical vehicle(HEV), electric generating system(EGS) driven by sphere cam engine(SCE) is said to own higher power density and integration. In this work, the structure and working principle of EGS were introduced, based on which the advantages of EGS were displayed. The profile of sphere cam was achieved after the desired motion of piston was given. After establishing the dynamic model of power transmission mechanism, the characteristics of cam-roller mechanism were studied. The results show that the optimal cam profile of SCE is a sinusoid curve which has two peaks and two valleys and a mean pressure angle of 47.19°. Because of the special cam shape, the trace of end surface center of piston is an eight-shape curve on a specific sphere surface. SCE running at speed of 3000 r/min can generate the power of 33.81 kW, which could satisfy the need of HEVs. However, the force between cylinder and piston skirt caused by Coriolis acceleration can reach up to 1182 N, which leads to serious wear between cylinder liner and piston skirt and may shorten the lifespan of SCE.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51005115, 51205191, and 51005248)the Visiting Scholar Foundation of the State Key Laboratory of Mechanical Transmission in Chongqing University+1 种基金the Research Foundation of National Engineering Laboratory for Electric Vehicles (Grant No. 2012-NELEV-03)the Science Fund of State Key Laboratory of Automotive Safety and Energy(Grant No. KF11202)
文摘Based on the multidiscipline design optimization theory, a multidiscipline collaborative optimization model of the differential steering system of electric vehicle with motorized wheels is built, with the steering economy as the main system and the steering road feel, the steering flexibility and the mechanic character of the steering sensors as the subsystems. Considering the coupled relationship of each discipline, the main system is optimized by the multi-island algorithm and the subsystems are optimized by the sequential quadratic programming algorithm. The simulation results show that the steering economy can be optimized by the collaborative optimization, and that the system can get good steering road feel, good steering flexibility and good mechanic character of the steering sensors.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51005115 and 51005248)the Science Fund of State Key Laboratory of Automotive Safety and Energy (Grant No. KF11201)
文摘The model of the differential steering system(DSS) of electric vehicle with motorized wheels and the three-degree-of-freedom dynamic model of vehicle are built.Based on these models,the concepts and quantitative expressions of steering road feel,steering portability and steering stability are proposed.Through integrating the Monte Carlo descriptive sampling,elitist non-dominated sorting genetic algorithm(NSGA-II) and Taguchi robust design method,the system parameters are optimized with steering road feel and steering portability as optimization targets,and steering stability and steering portability as constraints.The simulation results show that the system optimized based on quality engineering can improve the steering road feel,guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the electric vehicle with motorized wheels system.
