Aiming at the problems of low target image resolution,insufficient target feature extraction,low detection accuracy and poor real time in remote engineering vehicle detection,an improved CenterNet target detection mod...Aiming at the problems of low target image resolution,insufficient target feature extraction,low detection accuracy and poor real time in remote engineering vehicle detection,an improved CenterNet target detection model is proposed in this paper.Firstly,EfficientNet-B0 with Efficient Channel Attention(ECA)module is used as the basic network,which increases the quality and speed of feature extraction and reduces the number of model parameters.Then,the proposed Adaptive Fusion Bidirectional Feature Pyramid Network(AF-BiFPN)module is applied to fuse the features of different feature layers.Furthermore,the feature information of engineering vehicle targets is added by making full use of the high-level semantic and low-level fine-grained feature information of the target,which overcomes the problem that the original CenterNet network did not perform well in small target detection and improve the detection accuracy of the network.Finally,the tag coding strategy and bounding box regression method of CenterNet are optimized by introducing positioning quality loss.The accuracy of target prediction is increased by joint prediction of center position and target size.Experimental results show that the mean Average Precision(mAP)of the improved CenterNet model is 94.74%on the engineering vehicle dataset,and the detection rate is 29 FPS.Compared with the original CenterNet model based on ResNet-18,the detection accuracy of this model is improved by 16.29%,the detection speed is increased by 9 FPS,and the memory usage is reduced by 43 MB.Compared with YOLOv3 and YOLOv4,the mAP of this model is improved by 19.9%and 5.61%respectively.The proposed method can detect engineering vehicles more quickly and accurately in far distance.It has obvious advantages in target detection compared with traditional methods.展开更多
New energy vehicles represent the inevitable trend of future development.Compared to traditional fuel vehicles,they are more energy-saving and environmentally friendly,effectively reducing air pollution and mitigating...New energy vehicles represent the inevitable trend of future development.Compared to traditional fuel vehicles,they are more energy-saving and environmentally friendly,effectively reducing air pollution and mitigating excessive exploitation of oil resources,a stance strongly supported by governments.However,new energy vehicles possess certain drawbacks in terms of price and usability compared to traditional counterparts.Therefore,external support is imperative for their development.This paper delineates four main sections:the background of new energy vehicle promotion and application,a comparative analysis of domestic and foreign promotion models,specific promotion suggestions,and future development prospects.By leveraging insights from economic analysis,the optimal promotion model for new energy vehicles is elucidated.展开更多
Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called...Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called cyclic operation.To deal with that,section method can be applied.However,this method will neglect those transition cycles caused by switching load section,which can contribute a lot to fatigue.In order to consider those transition cycles,this paper applied the model called“Switching Markov Chain of Turning Points”(SMCTP).Then the expected rain-flow matrix is compared with the overall rain-flow matrix conducted by section method.The comparison result shows that SMCTP can perform well in processing nonstationary loadings.As a result,the Switching Markov Chain method(SMC)was proved to be effective in stochastically characterizing the nonstationary switching loadings of engineering vehicles.展开更多
Under the background of"Outstanding Engineer Education and Training Program"and ideology and politics teaching in course,it has become a training goal for colleges and universities to cultivate an engineer w...Under the background of"Outstanding Engineer Education and Training Program"and ideology and politics teaching in course,it has become a training goal for colleges and universities to cultivate an engineer with both political integrity and talent.However,it is necessary for colleges and universities to explore and practice how to combine the two skillfully without being abrupt and make students accept them.From the point of view of vehicle engineering experiment course and combining with the current situation of university teaching,this paper makes an in-depth exploration and practice on the ideological and political reform on vehicle engineering experiment course.展开更多
In view of the problem of the teaching effect of the vehicle specialty courses,this paper analyzes the training objectives of the courses,determines the teaching contents and relevant teaching methods,and provides spe...In view of the problem of the teaching effect of the vehicle specialty courses,this paper analyzes the training objectives of the courses,determines the teaching contents and relevant teaching methods,and provides specific teaching measures to improve the students'ability to solve practical problems and employment ability,so as to cultivate the application-oriented talents with innovation ability and practical ability that meet the needs of the society.展开更多
Under the situation of actively constructing the education pattern of ideological and political courses in our country,talents with excellent professional quality and excellent ideological and moral quality have becom...Under the situation of actively constructing the education pattern of ideological and political courses in our country,talents with excellent professional quality and excellent ideological and moral quality have become the training goal of current college education.However,what way should be adopted to better integrate ideological and political education with professional knowledge education will be the answer that colleges and universities need to constantly explore.This paper starts from the professional courses of vehicle engineering,combined with the current situation of China's automobile industry,to study practical reform methods,construct the pattern of whole curriculum education.展开更多
In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and researc...In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and research,including characteristics of software,application scope and methods are presented in this paper.Through these industries aided software powerful calculation,analysis functions and convenient visualization means,for the virtual simulation experiment,it can help to clearly illustrate the concept,deepen students’ understanding level of vehicle professional course,improve the enthusiasm of the students,improve the ability of autonomous learning and improve students ’ thinking ability and practice ability,and can effectively train highquality professionals with good quality.展开更多
New energy vehicles have better clean and environmental protection characteristics than traditional fuel vehicles.The new energy engine cooling technology is critical in the design of new energy vehicles.This paper us...New energy vehicles have better clean and environmental protection characteristics than traditional fuel vehicles.The new energy engine cooling technology is critical in the design of new energy vehicles.This paper used oneand three-way joint simulation methods to simulate the refrigeration system of new energy vehicles.Firstly,a k-εturbulent flow model for the cooling pump flow field is established based on the principle of computational fluid dynamics.Then,the CFD commercial fluid analysis software FLUENT is used to simulate the flow field of the cooling pump under different inlet flow conditions.This paper proposes an optimization scheme for new energy vehicle engines’“boiling”phenomenon under high temperatures and long-time climbing conditions.The simulation results show that changing the radiator’s structure and adjusting the thermostat’s parameters can solve the problem of a“boiling pot.”The optimized new energy vehicle engine can maintain a better operating temperature range.The algorithm model can reference each cryogenic system component hardware selection and control strategy in the new energy vehicle’s engine.展开更多
New shift schedule for automatic transmission is proposed from the point ofview of saving energy. The bench-test of automatic shift adopting this shift schedule is done onautomatic transmission's test-bed. The exp...New shift schedule for automatic transmission is proposed from the point ofview of saving energy. The bench-test of automatic shift adopting this shift schedule is done onautomatic transmission's test-bed. The experimental results show the shift schedule is correct. Thisshift schedule has enriched the theory of vehicle automatic maneuvering and will improve theefficiency of hydrodynamic drive system of the vehicle.展开更多
This paper applies the fractal dimension as a characteristic to describe the engine抯 operating condition and its developmental trend. A correlation dimension is one of the quantities that are usually used to characte...This paper applies the fractal dimension as a characteristic to describe the engine抯 operating condition and its developmental trend. A correlation dimension is one of the quantities that are usually used to characterize a strange attractor. With the operation of the phase space reconstruction, respective correlation dimensions of a series of vibration signals obtained under different conditions are calculated to find the intrinsic relationship between the indicator and the operating condition. The experiment result shows that the correlation dimension is sensitive to the condition evolution and convenient for the identification of abnormal operational states. In advanced prognostic algorithm based on the BP neural network is then applied on the correlation dimensions to predict the short-term running conditions in order to avoid severe faults and realize in-time maintenance. Experimental results are presented to illustrate the proposed methodology.展开更多
A speed control analysis for an in-line gasoline fueled internal combustion (IC) engine is presented for the purpose of alleviation of high frequency oscillations in engine revolutions. A dynamic cylinder-by-cylinde...A speed control analysis for an in-line gasoline fueled internal combustion (IC) engine is presented for the purpose of alleviation of high frequency oscillations in engine revolutions. A dynamic cylinder-by-cylinder model is proposed, base on slider-crank mechanism, which is extended to develop a digital governor providing a high fidelity estimation of rotary speed oscillation for hybrid vehicle engines. A modified PID controller that P and I gain is placed in feedback path is also described for hybrid electric vehicle (HEV) engine speed regulation, By comparison between measured and estimated signals, it is demonstrated that a good agreement has been achieved and the governor behaves an excellent damping speed ripple.展开更多
The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic conver...The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite (S.I.) engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.展开更多
In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamic...In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamics, the rigid-flexible coupled dynamic model of metro vehicle-track-LSCSB system is established by using finite element method and multi-rigid-body dynamics. Adopting this model, the deformation of LSCSB subject to temperature is analyzed, then the comprehensive effect of track random irregularity and rail deformation caused by temperature load is considered to study the dynamic characteristics of metro vehicle running through the bridge, and finally the influences of temperature increment and running speed on concerned dynamic indices of vehicle are studied. The results show that the LSCSB deforms obviously subject to temperature load, and the overall performance is that the cooling is arched, and the heating is bent, and the shape variable changes almost linearly with the temperature load. According to the parameters studied in this paper, the rail deformation caused by temperature load increases the wheel-rail vertical force, derailment coefficient and wheel load reduction rate by 1.5%, 3.1% and 5% respectively. The vertical acceleration of the vehicle body decreases by 2.4% under the cooling condition, while increases by 3.7% under the heating condition. The dynamic response of the bridge changes under temperature load. The maximum vertical and horizontal displacement in the middle of the main beam span are 6.24 mm and 2.19 mm respectively, and the maximum vertical and horizontal acceleration are 1.29 cm/s<sup>2</sup> and 2.54cm/s<sup>2</sup> respectively. The derailment coefficient and vertical acceleration of vehicle body are more affected by temperature load, and the wheel load reduction rate and wheel-rail vertical force are more affected by speed. The conclusion of this paper provides a reference for subsequent scholars to study the influence of thermal deformation on the dynamic response of vehicles on LSCSB.展开更多
From the point of view of saving energy, a new shift schedule and auto-controlling strategy for automatic transmission are proposed. In order to verify this shift schedule, a simulation program using a software packag...From the point of view of saving energy, a new shift schedule and auto-controlling strategy for automatic transmission are proposed. In order to verify this shift schedule, a simulation program using a software package of Matlab/ Simulink is developed. The simulation results show the shift schedule is correct. This shift schedule has enriched the theory of vehicle automatic maneuvering and will improve the efficiency of hydrodynanic drive system of the vehicle.展开更多
Both the seat and cab system of truck play a vital role in ride comfort.The damping matching methods of the two systems are studied separately at present.However,the driver,seat,and cab system are one inseparable whol...Both the seat and cab system of truck play a vital role in ride comfort.The damping matching methods of the two systems are studied separately at present.However,the driver,seat,and cab system are one inseparable whole.In order to further improve ride comfort,the seat suspension is regarded as the fifth suspension of the cab,a new idea of "Five-suspensions" is proposed.Based on this idea,a 4 degree-of-freedom driver-seat-cab coupled system model is presented.Using the tested cab suspensions excitations as inputs and seat acceleration response as compared output,the simulation model is built.Taking optimal ride comfort as target,a new method of damping collaborative optimization for Five-suspensions is proposed.With a practical example of seat and cab system,the damping parameters are optimized and validated by simulation and bench test.The results show the seat vertical frequency-weighted RMS acceleration values tested for the un-optimized and optimized Five-suspensions are 0.50 m/s~2 and 0.39 m/s~2,respectively,with a decrease by 22.0%,which proves the model and method proposed are correct and reliable.The idea of "Five-suspensions" and the method proposed provide a reference for achieving global optimal damping matching of seat suspension and cab suspensions.展开更多
Full frontal impact theory needs researching and exploring to satisfy the primary safety design of occupant restraint system,avoiding the increasingly "engineering"trend in order to develop and design safety...Full frontal impact theory needs researching and exploring to satisfy the primary safety design of occupant restraint system,avoiding the increasingly "engineering"trend in order to develop and design safety vehicle. After occupant restraint system is simulated by using linear elastic stiffness k,the occupant-vehicle frontal rigid barrier impact model is established. Dynamic equation of dummy chest coupling vehicle is built for full frontal impact based on ordinary vehicle deceleration by Hooke law,and the equation is solved by comparing coefficient and satisfying boundary qualifications. While relative vehicle characteristic parameters are kept unchanging,the actual vehicle deceleration is fitted to the simplified equivalent square wave( ESW),tipped equivalent square wave( TESW) and equivalent dual trapezoids wave( EDTW). Phase angle and amplitude A of dynamic equations based on ESW,TESW and EDTW are calculated and deduced. The results show that: the dynamic equation of dummy chest coupling vehicle can be well utilized to instruct the primary safety design of full frontal impact for objective vehicle to satisfy chest deceleration demands and the equation based on TESW is best for this design.展开更多
This paper presents an energy management optimization system based on an adaptive functional state model of battery aging for internal combustion engine vehicles(ICEVs).First,the functional characteristics of batterie...This paper presents an energy management optimization system based on an adaptive functional state model of battery aging for internal combustion engine vehicles(ICEVs).First,the functional characteristics of batteries in ICEVs are investigated.Then,an adaptive functional state model is proposed to represent battery aging throughout the entire battery service life.A battery protection scheme is developed,including over-discharge and graded over-current protection to improve battery safety.A model-based energy management strategy is synthesized to comprehensively optimize fuel economy,battery life preservation,and vehicle performance.The performance of the proposed scheme was examined under comprehensive test scenarios based on field and bench tests.The results show that the proposed energy management algorithm can effectively improve fuel economy.展开更多
With the rapid expansion of the global motor vehicle population,the transportation sector has taken up a growing proportion among all the carbon dioxide emissionrelated sectors.To contribute to solutions of the carbon...With the rapid expansion of the global motor vehicle population,the transportation sector has taken up a growing proportion among all the carbon dioxide emissionrelated sectors.To contribute to solutions of the carbon dioxide-oriented problem in transportation,this paper proposes the“ALL FREE”concept that applies partial oxidation process instead of the conventional complete oxidation to vehicle engines.In such an engine,the fuels are partially oxidized into corresponding chemical products,which,as a result,enable the process to be theoretically free of CO_(2),while the heat output of the partial oxidation could drive the vehicle.On the other hand,the resulting products are of great value,which could decrease or even counteract the cost of fuels in transportation.In this paper,the thermodynamic and kinetic data(e.g.,the heat output and heat release rate)of five selected partial oxidation reactions were calculated at length to demonstrate and exemplify the theoretical feasibility of the“ALL FREE”concept.It turned out that the partial oxidation of n-butane to maleic anhydride has the most potential to meet the basic requirements of this concept.To sum up,this design concept is of significant application potential for the reduction of CO_(2)emissions in the transportation industry,although there remain many technical challenges.展开更多
The diffusion of new energy vehicles(NEVs),such as battery electric vehicles(BEVs)and fuel cell vehicles(FCVs),is critical to the transportation sector's deep decarbonization.The cost of energy chains is an import...The diffusion of new energy vehicles(NEVs),such as battery electric vehicles(BEVs)and fuel cell vehicles(FCVs),is critical to the transportation sector's deep decarbonization.The cost of energy chains is an important factor in the diffusion of NEVs.Although researchers have addressed the technological learning effect of NEVs and the life cycle emissions associated with the diffusion of NEVs,little work has been conducted to analyze the life cycle costs of different energy chains associated with different NEVs in consideration of technological learning potential.Thus,relevant information on investment remains insufficient to promote the deployment of NEVs.This study proposes a systematic framework that includes various(competing or coordinated)energy chains of NEVs formed with different technologies of power generation and transmission,hydrogen production and transportation,power-to-liquid fuel,and fuel transportation.The levelized costs of three typical carbon-neutral energy chains are investigated using the life cycle cost model and considering the technological learning effect.Results show that the current well-to-pump levelized costs of the energy chains in China for BEVs,FCVs,and internal combustion engine vehicles(ICEVs)are approximately 3.60,4.31,and 2.21 yuan/GJ,respectively,and the well-to-wheel levelized costs are 4.50,6.15,and 7.51 yuan/GJ,respectively.These costs primarily include raw material costs and they vary greatly for BEVs and FCVs from resource and consumer costs.In consideration of the technological learning effect,the energy chains'well-to-wheel levelized costs are expected todecrease by 24.82%for BEVs,27.12%for FCVs,and 19.25%for ICEVs by 2060.This work also summarizes policy recommendations on developing energy chains to promote the diffusion of NEVs in China.展开更多
A new law on vehicle tax, to encourage the use of smaller engines to reduce pollution and oil dependence by collecting tax on the basis of engine capacity, is under consideration.
基金This research was funded by College Student Innovation and Entrepreneurship Training Program,Grant Number 2021055Z and S202110082031the Special Project for Cultivating Scientific and Technological Innovation Ability of College and Middle School Students in Hebei Province,Grant Number 2021H011404.
文摘Aiming at the problems of low target image resolution,insufficient target feature extraction,low detection accuracy and poor real time in remote engineering vehicle detection,an improved CenterNet target detection model is proposed in this paper.Firstly,EfficientNet-B0 with Efficient Channel Attention(ECA)module is used as the basic network,which increases the quality and speed of feature extraction and reduces the number of model parameters.Then,the proposed Adaptive Fusion Bidirectional Feature Pyramid Network(AF-BiFPN)module is applied to fuse the features of different feature layers.Furthermore,the feature information of engineering vehicle targets is added by making full use of the high-level semantic and low-level fine-grained feature information of the target,which overcomes the problem that the original CenterNet network did not perform well in small target detection and improve the detection accuracy of the network.Finally,the tag coding strategy and bounding box regression method of CenterNet are optimized by introducing positioning quality loss.The accuracy of target prediction is increased by joint prediction of center position and target size.Experimental results show that the mean Average Precision(mAP)of the improved CenterNet model is 94.74%on the engineering vehicle dataset,and the detection rate is 29 FPS.Compared with the original CenterNet model based on ResNet-18,the detection accuracy of this model is improved by 16.29%,the detection speed is increased by 9 FPS,and the memory usage is reduced by 43 MB.Compared with YOLOv3 and YOLOv4,the mAP of this model is improved by 19.9%and 5.61%respectively.The proposed method can detect engineering vehicles more quickly and accurately in far distance.It has obvious advantages in target detection compared with traditional methods.
文摘New energy vehicles represent the inevitable trend of future development.Compared to traditional fuel vehicles,they are more energy-saving and environmentally friendly,effectively reducing air pollution and mitigating excessive exploitation of oil resources,a stance strongly supported by governments.However,new energy vehicles possess certain drawbacks in terms of price and usability compared to traditional counterparts.Therefore,external support is imperative for their development.This paper delineates four main sections:the background of new energy vehicle promotion and application,a comparative analysis of domestic and foreign promotion models,specific promotion suggestions,and future development prospects.By leveraging insights from economic analysis,the optimal promotion model for new energy vehicles is elucidated.
基金National Natural Science Foundation of China(Grant No.51375202)National Natural science fund project(Grant No.51265020)Jilin Province Science and Technology Development Project(No.20160101285JC).
文摘Engineering vehicles are widely used under various harsh working conditions.For many components in them,service loadings they suffered are usually random and nonstationary due to their remarkable characteristic called cyclic operation.To deal with that,section method can be applied.However,this method will neglect those transition cycles caused by switching load section,which can contribute a lot to fatigue.In order to consider those transition cycles,this paper applied the model called“Switching Markov Chain of Turning Points”(SMCTP).Then the expected rain-flow matrix is compared with the overall rain-flow matrix conducted by section method.The comparison result shows that SMCTP can perform well in processing nonstationary loadings.As a result,the Switching Markov Chain method(SMC)was proved to be effective in stochastically characterizing the nonstationary switching loadings of engineering vehicles.
基金supported by Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology(JGYJ-2019038)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology at Weihai(WH2019010)Teaching Research Project of Harbin Institute of Technology at Weihai(BKQN201905).
文摘Under the background of"Outstanding Engineer Education and Training Program"and ideology and politics teaching in course,it has become a training goal for colleges and universities to cultivate an engineer with both political integrity and talent.However,it is necessary for colleges and universities to explore and practice how to combine the two skillfully without being abrupt and make students accept them.From the point of view of vehicle engineering experiment course and combining with the current situation of university teaching,this paper makes an in-depth exploration and practice on the ideological and political reform on vehicle engineering experiment course.
基金supported by Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology(JGYJ-2019038)Postgraduate Education and Teaching Reform Project of Harbin Institute of Technology at Weihai(WH2019010)Teaching Research Project of Harbin Institute of Technology at Weihai(BKQN201905).
文摘In view of the problem of the teaching effect of the vehicle specialty courses,this paper analyzes the training objectives of the courses,determines the teaching contents and relevant teaching methods,and provides specific teaching measures to improve the students'ability to solve practical problems and employment ability,so as to cultivate the application-oriented talents with innovation ability and practical ability that meet the needs of the society.
文摘Under the situation of actively constructing the education pattern of ideological and political courses in our country,talents with excellent professional quality and excellent ideological and moral quality have become the training goal of current college education.However,what way should be adopted to better integrate ideological and political education with professional knowledge education will be the answer that colleges and universities need to constantly explore.This paper starts from the professional courses of vehicle engineering,combined with the current situation of China's automobile industry,to study practical reform methods,construct the pattern of whole curriculum education.
基金supported by Henan Polytechnic University Education Teaching Reform Research Projects(No.2015JG034)
文摘In order to overcome the limitation of vehicle engineering professional laboratory personnel and facilities,some of them is commonly used auxiliary software in the professional field for design,calculation and research,including characteristics of software,application scope and methods are presented in this paper.Through these industries aided software powerful calculation,analysis functions and convenient visualization means,for the virtual simulation experiment,it can help to clearly illustrate the concept,deepen students’ understanding level of vehicle professional course,improve the enthusiasm of the students,improve the ability of autonomous learning and improve students ’ thinking ability and practice ability,and can effectively train highquality professionals with good quality.
文摘New energy vehicles have better clean and environmental protection characteristics than traditional fuel vehicles.The new energy engine cooling technology is critical in the design of new energy vehicles.This paper used oneand three-way joint simulation methods to simulate the refrigeration system of new energy vehicles.Firstly,a k-εturbulent flow model for the cooling pump flow field is established based on the principle of computational fluid dynamics.Then,the CFD commercial fluid analysis software FLUENT is used to simulate the flow field of the cooling pump under different inlet flow conditions.This paper proposes an optimization scheme for new energy vehicle engines’“boiling”phenomenon under high temperatures and long-time climbing conditions.The simulation results show that changing the radiator’s structure and adjusting the thermostat’s parameters can solve the problem of a“boiling pot.”The optimized new energy vehicle engine can maintain a better operating temperature range.The algorithm model can reference each cryogenic system component hardware selection and control strategy in the new energy vehicle’s engine.
基金This project is supported by National Natural Science Foundation of China (No.59705005).
文摘New shift schedule for automatic transmission is proposed from the point ofview of saving energy. The bench-test of automatic shift adopting this shift schedule is done onautomatic transmission's test-bed. The experimental results show the shift schedule is correct. Thisshift schedule has enriched the theory of vehicle automatic maneuvering and will improve theefficiency of hydrodynamic drive system of the vehicle.
文摘This paper applies the fractal dimension as a characteristic to describe the engine抯 operating condition and its developmental trend. A correlation dimension is one of the quantities that are usually used to characterize a strange attractor. With the operation of the phase space reconstruction, respective correlation dimensions of a series of vibration signals obtained under different conditions are calculated to find the intrinsic relationship between the indicator and the operating condition. The experiment result shows that the correlation dimension is sensitive to the condition evolution and convenient for the identification of abnormal operational states. In advanced prognostic algorithm based on the BP neural network is then applied on the correlation dimensions to predict the short-term running conditions in order to avoid severe faults and realize in-time maintenance. Experimental results are presented to illustrate the proposed methodology.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2001AA501211).
文摘A speed control analysis for an in-line gasoline fueled internal combustion (IC) engine is presented for the purpose of alleviation of high frequency oscillations in engine revolutions. A dynamic cylinder-by-cylinder model is proposed, base on slider-crank mechanism, which is extended to develop a digital governor providing a high fidelity estimation of rotary speed oscillation for hybrid vehicle engines. A modified PID controller that P and I gain is placed in feedback path is also described for hybrid electric vehicle (HEV) engine speed regulation, By comparison between measured and estimated signals, it is demonstrated that a good agreement has been achieved and the governor behaves an excellent damping speed ripple.
基金This project is supported by Provincial Natural Science Foundation of Guangdong, China and Provincial Environmental Protection Science Foundation of Guangdong, China(No.320-D38000).
文摘The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation (EGR), thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite (S.I.) engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.
文摘In order to study the influence of thermal deformation of long-span cable- stayed bridge (LSCSB) on the dynamic characteristics of metro vehicle on the bridge, based on the theory of vehicle-track coupled dynamics, the rigid-flexible coupled dynamic model of metro vehicle-track-LSCSB system is established by using finite element method and multi-rigid-body dynamics. Adopting this model, the deformation of LSCSB subject to temperature is analyzed, then the comprehensive effect of track random irregularity and rail deformation caused by temperature load is considered to study the dynamic characteristics of metro vehicle running through the bridge, and finally the influences of temperature increment and running speed on concerned dynamic indices of vehicle are studied. The results show that the LSCSB deforms obviously subject to temperature load, and the overall performance is that the cooling is arched, and the heating is bent, and the shape variable changes almost linearly with the temperature load. According to the parameters studied in this paper, the rail deformation caused by temperature load increases the wheel-rail vertical force, derailment coefficient and wheel load reduction rate by 1.5%, 3.1% and 5% respectively. The vertical acceleration of the vehicle body decreases by 2.4% under the cooling condition, while increases by 3.7% under the heating condition. The dynamic response of the bridge changes under temperature load. The maximum vertical and horizontal displacement in the middle of the main beam span are 6.24 mm and 2.19 mm respectively, and the maximum vertical and horizontal acceleration are 1.29 cm/s<sup>2</sup> and 2.54cm/s<sup>2</sup> respectively. The derailment coefficient and vertical acceleration of vehicle body are more affected by temperature load, and the wheel load reduction rate and wheel-rail vertical force are more affected by speed. The conclusion of this paper provides a reference for subsequent scholars to study the influence of thermal deformation on the dynamic response of vehicles on LSCSB.
基金This project is supported by National Natural Science Foundation of China( No.59705005) and Backbone Teacher Foundation of Minis
文摘From the point of view of saving energy, a new shift schedule and auto-controlling strategy for automatic transmission are proposed. In order to verify this shift schedule, a simulation program using a software package of Matlab/ Simulink is developed. The simulation results show the shift schedule is correct. This shift schedule has enriched the theory of vehicle automatic maneuvering and will improve the efficiency of hydrodynanic drive system of the vehicle.
基金Supported by National Natural Science Foundation of China(Grant No.51575325)Shandong Provincial Natural Science Foundation of China(Grant No.ZR2013EEM007)
文摘Both the seat and cab system of truck play a vital role in ride comfort.The damping matching methods of the two systems are studied separately at present.However,the driver,seat,and cab system are one inseparable whole.In order to further improve ride comfort,the seat suspension is regarded as the fifth suspension of the cab,a new idea of "Five-suspensions" is proposed.Based on this idea,a 4 degree-of-freedom driver-seat-cab coupled system model is presented.Using the tested cab suspensions excitations as inputs and seat acceleration response as compared output,the simulation model is built.Taking optimal ride comfort as target,a new method of damping collaborative optimization for Five-suspensions is proposed.With a practical example of seat and cab system,the damping parameters are optimized and validated by simulation and bench test.The results show the seat vertical frequency-weighted RMS acceleration values tested for the un-optimized and optimized Five-suspensions are 0.50 m/s~2 and 0.39 m/s~2,respectively,with a decrease by 22.0%,which proves the model and method proposed are correct and reliable.The idea of "Five-suspensions" and the method proposed provide a reference for achieving global optimal damping matching of seat suspension and cab suspensions.
基金Sponsored by the National Science and Technology Support Program of China(Grant No.2011BAG02B02)
文摘Full frontal impact theory needs researching and exploring to satisfy the primary safety design of occupant restraint system,avoiding the increasingly "engineering"trend in order to develop and design safety vehicle. After occupant restraint system is simulated by using linear elastic stiffness k,the occupant-vehicle frontal rigid barrier impact model is established. Dynamic equation of dummy chest coupling vehicle is built for full frontal impact based on ordinary vehicle deceleration by Hooke law,and the equation is solved by comparing coefficient and satisfying boundary qualifications. While relative vehicle characteristic parameters are kept unchanging,the actual vehicle deceleration is fitted to the simplified equivalent square wave( ESW),tipped equivalent square wave( TESW) and equivalent dual trapezoids wave( EDTW). Phase angle and amplitude A of dynamic equations based on ESW,TESW and EDTW are calculated and deduced. The results show that: the dynamic equation of dummy chest coupling vehicle can be well utilized to instruct the primary safety design of full frontal impact for objective vehicle to satisfy chest deceleration demands and the equation based on TESW is best for this design.
基金supported by National Natural Science Foundation of China(Grant No.52002209)Beijing Nova Program,and the State Key Laboratory of Automotive Safety and Energy(Grant No.KFY2210).
文摘This paper presents an energy management optimization system based on an adaptive functional state model of battery aging for internal combustion engine vehicles(ICEVs).First,the functional characteristics of batteries in ICEVs are investigated.Then,an adaptive functional state model is proposed to represent battery aging throughout the entire battery service life.A battery protection scheme is developed,including over-discharge and graded over-current protection to improve battery safety.A model-based energy management strategy is synthesized to comprehensively optimize fuel economy,battery life preservation,and vehicle performance.The performance of the proposed scheme was examined under comprehensive test scenarios based on field and bench tests.The results show that the proposed energy management algorithm can effectively improve fuel economy.
文摘With the rapid expansion of the global motor vehicle population,the transportation sector has taken up a growing proportion among all the carbon dioxide emissionrelated sectors.To contribute to solutions of the carbon dioxide-oriented problem in transportation,this paper proposes the“ALL FREE”concept that applies partial oxidation process instead of the conventional complete oxidation to vehicle engines.In such an engine,the fuels are partially oxidized into corresponding chemical products,which,as a result,enable the process to be theoretically free of CO_(2),while the heat output of the partial oxidation could drive the vehicle.On the other hand,the resulting products are of great value,which could decrease or even counteract the cost of fuels in transportation.In this paper,the thermodynamic and kinetic data(e.g.,the heat output and heat release rate)of five selected partial oxidation reactions were calculated at length to demonstrate and exemplify the theoretical feasibility of the“ALL FREE”concept.It turned out that the partial oxidation of n-butane to maleic anhydride has the most potential to meet the basic requirements of this concept.To sum up,this design concept is of significant application potential for the reduction of CO_(2)emissions in the transportation industry,although there remain many technical challenges.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.72131007,7214006,and 72074077)Open access funding provided by International Institute for Applied Systems Analysis(IIASA).
文摘The diffusion of new energy vehicles(NEVs),such as battery electric vehicles(BEVs)and fuel cell vehicles(FCVs),is critical to the transportation sector's deep decarbonization.The cost of energy chains is an important factor in the diffusion of NEVs.Although researchers have addressed the technological learning effect of NEVs and the life cycle emissions associated with the diffusion of NEVs,little work has been conducted to analyze the life cycle costs of different energy chains associated with different NEVs in consideration of technological learning potential.Thus,relevant information on investment remains insufficient to promote the deployment of NEVs.This study proposes a systematic framework that includes various(competing or coordinated)energy chains of NEVs formed with different technologies of power generation and transmission,hydrogen production and transportation,power-to-liquid fuel,and fuel transportation.The levelized costs of three typical carbon-neutral energy chains are investigated using the life cycle cost model and considering the technological learning effect.Results show that the current well-to-pump levelized costs of the energy chains in China for BEVs,FCVs,and internal combustion engine vehicles(ICEVs)are approximately 3.60,4.31,and 2.21 yuan/GJ,respectively,and the well-to-wheel levelized costs are 4.50,6.15,and 7.51 yuan/GJ,respectively.These costs primarily include raw material costs and they vary greatly for BEVs and FCVs from resource and consumer costs.In consideration of the technological learning effect,the energy chains'well-to-wheel levelized costs are expected todecrease by 24.82%for BEVs,27.12%for FCVs,and 19.25%for ICEVs by 2060.This work also summarizes policy recommendations on developing energy chains to promote the diffusion of NEVs in China.
文摘A new law on vehicle tax, to encourage the use of smaller engines to reduce pollution and oil dependence by collecting tax on the basis of engine capacity, is under consideration.