The existing investigations of vehicle ride comfort mainly include motion characteristics analysis based on creating a multi-body dynamic simulation model,and the parameters analysis to improve the suspension control ...The existing investigations of vehicle ride comfort mainly include motion characteristics analysis based on creating a multi-body dynamic simulation model,and the parameters analysis to improve the suspension control for the target.In the study of creating multi-body dynamics simulation models,there is usually without considering calibration and test verification,which make it difficult to ensure the production of engineering.In the study of improving the suspension control parameters for the target,there is a lack of systematic match about comfortable and human characteristics,so it is difficult to implement in the field of driving and leading the vehicle design.In this paper,based on the different characteristic of suspension system that effects on the vehicle ride comfort, according to the suspension system dynamic mechanism,the research methods of vehicle road test,bench test and CAE simulation is used,at the same time,several sensitivity analysis of vehicle ride comfort related to suspension stiffness and damping and speed is made. As a result,the key suspension systematic parameters are given that have important impact on vehicle ride comfort.Through matching parameters,a calibration analysis of suspension system based on human comfort is obtained.The analysis results show that the analysis methods for the design target of making the vehicle with best comfort are effective.On the basis of the theory study,five suspension parameter matching principles are explored to promise the vehicle with perfect ride comfort,which also provide theoretical basis and design methods for the passenger car best match of suspension system stiffness and damping.The research results have the promotional value of practicability and a wide range of engineering application.展开更多
Pre-heat treatment is a vital step before cold ring rolling and it has significant effect on the microstructure and mechanical properties of rolled rings.The 100Cr6 steel rings were subjected to pre-heat treatment and...Pre-heat treatment is a vital step before cold ring rolling and it has significant effect on the microstructure and mechanical properties of rolled rings.The 100Cr6 steel rings were subjected to pre-heat treatment and subsequent cold rolling process.Scanning electron microscopy and tensile tests were applied to investigate microstructure characteristic and mechanical property variations of 100Cr6 steel rings undergoing different pre-heat treatings.The results indicate that the average diameter of carbide particles,the tensile strength and hardness increase,while the elongation decreases with the decrease of cooling rate.The cooling rate has minor effect on the yield strength of sample.After cold ring rolling,the ferrite matrix shows a clear direction along the rolling direction.The distribution of cementite is more homogeneous and the cementite particles are finer.Meanwhile,the hardness of the rolled ring is higher than that before rolling.展开更多
Desktop calibration of automatic transmission(AT) is a method which can reduce cost, enhance efficiency and shorten the development periods of a vehicle effectively. We primary introduced the principle and approach of...Desktop calibration of automatic transmission(AT) is a method which can reduce cost, enhance efficiency and shorten the development periods of a vehicle effectively. We primary introduced the principle and approach of desktop calibration of AT based on the condition of coupling characteristics between engine and torque converter and obtained right point exactly. It is shown to agree with experimental measurements reasonably well. It was used in different applications abroad based on AT technology and achieved a good performance of the vehicle compared with traditional AT technology which primary focuses on the drivability, performance and fuel consumption.展开更多
In this article,a systematic assessment of cyber-physical security is developed for the lane-keeping control(LKC)system of autonomous vehicles(AVs),which has not been attempted before.A novel impact analysis methodolo...In this article,a systematic assessment of cyber-physical security is developed for the lane-keeping control(LKC)system of autonomous vehicles(AVs),which has not been attempted before.A novel impact analysis methodology for typical cyber-attacks is proposed with new evaluation metrics from the viewpoint of safety and performance and innovative index-based resilience and security criteria.Specifically,a security criterion is investigated by tracking performance,comfort and vehicle stability to evaluate the safety and security of the vehicle LKC system.Hardware-in-the-Loop(HiL)experimental results show that the proposed evaluation metrics are effective in analyzing the impact of cyberattacks on the commercial LKC system of Dongfeng Motor comprehensively.Finally,the conclusion provides guidelines for attack detection,diagnosis,and countermeasures for AVs.展开更多
基金supported by National Hi-tech Research and Development Program of China(863 Program,Grant No. 2008AA11A123)Jilin Provincial Technology Department Development Plan of China(Grant No.20086006)
文摘The existing investigations of vehicle ride comfort mainly include motion characteristics analysis based on creating a multi-body dynamic simulation model,and the parameters analysis to improve the suspension control for the target.In the study of creating multi-body dynamics simulation models,there is usually without considering calibration and test verification,which make it difficult to ensure the production of engineering.In the study of improving the suspension control parameters for the target,there is a lack of systematic match about comfortable and human characteristics,so it is difficult to implement in the field of driving and leading the vehicle design.In this paper,based on the different characteristic of suspension system that effects on the vehicle ride comfort, according to the suspension system dynamic mechanism,the research methods of vehicle road test,bench test and CAE simulation is used,at the same time,several sensitivity analysis of vehicle ride comfort related to suspension stiffness and damping and speed is made. As a result,the key suspension systematic parameters are given that have important impact on vehicle ride comfort.Through matching parameters,a calibration analysis of suspension system based on human comfort is obtained.The analysis results show that the analysis methods for the design target of making the vehicle with best comfort are effective.On the basis of the theory study,five suspension parameter matching principles are explored to promise the vehicle with perfect ride comfort,which also provide theoretical basis and design methods for the passenger car best match of suspension system stiffness and damping.The research results have the promotional value of practicability and a wide range of engineering application.
基金Project(2011CB706605)supported by the National Basic Research Program of ChinaProject(2011CDA12)supported by the Innovative Research Groups of the Natural Science Foundation of Hubei Province,ChinaProjects(2012-Ia-017,2013-IV-014)supported by the Fundamental Research Funds for the Central Universities,China
文摘Pre-heat treatment is a vital step before cold ring rolling and it has significant effect on the microstructure and mechanical properties of rolled rings.The 100Cr6 steel rings were subjected to pre-heat treatment and subsequent cold rolling process.Scanning electron microscopy and tensile tests were applied to investigate microstructure characteristic and mechanical property variations of 100Cr6 steel rings undergoing different pre-heat treatings.The results indicate that the average diameter of carbide particles,the tensile strength and hardness increase,while the elongation decreases with the decrease of cooling rate.The cooling rate has minor effect on the yield strength of sample.After cold ring rolling,the ferrite matrix shows a clear direction along the rolling direction.The distribution of cementite is more homogeneous and the cementite particles are finer.Meanwhile,the hardness of the rolled ring is higher than that before rolling.
文摘Desktop calibration of automatic transmission(AT) is a method which can reduce cost, enhance efficiency and shorten the development periods of a vehicle effectively. We primary introduced the principle and approach of desktop calibration of AT based on the condition of coupling characteristics between engine and torque converter and obtained right point exactly. It is shown to agree with experimental measurements reasonably well. It was used in different applications abroad based on AT technology and achieved a good performance of the vehicle compared with traditional AT technology which primary focuses on the drivability, performance and fuel consumption.
基金supported in part by the National Natural Science Foundation of China under Grants No.U1964201,62373281 and 62333015part by Shanghai Municipal Science and Technology Commission No.23ZR1467700.
文摘In this article,a systematic assessment of cyber-physical security is developed for the lane-keeping control(LKC)system of autonomous vehicles(AVs),which has not been attempted before.A novel impact analysis methodology for typical cyber-attacks is proposed with new evaluation metrics from the viewpoint of safety and performance and innovative index-based resilience and security criteria.Specifically,a security criterion is investigated by tracking performance,comfort and vehicle stability to evaluate the safety and security of the vehicle LKC system.Hardware-in-the-Loop(HiL)experimental results show that the proposed evaluation metrics are effective in analyzing the impact of cyberattacks on the commercial LKC system of Dongfeng Motor comprehensively.Finally,the conclusion provides guidelines for attack detection,diagnosis,and countermeasures for AVs.