External human–machine interfaces(eHMIs)of highly automated vehicles(HAVs)have been developed to communicate vehicle intentions to pedestrians and other road users.This study conducted an online experiment with 33 pa...External human–machine interfaces(eHMIs)of highly automated vehicles(HAVs)have been developed to communicate vehicle intentions to pedestrians and other road users.This study conducted an online experiment with 33 participants to investigate the impact of a novel HAV’s eHMI of augmented reality(AR)crosswalks on pedestrian crossings using virtual simulation scenario videos and questionnaires.To verify the effectiveness of the AR crosswalk,comparative analyses were performed on eHMIs across 5 modalities:baseline,pedestrian silhouette,virtual eyes,AR headlight,and AR crosswalk,in conjunction with 2 vehicle physical modes(yielding and non-yielding).Metrics used in the study included crossing percentages before the HAV passed,crossing decision time,comprehensibility,and perceived safety.The results indicated that for yielding vehicles,the AR crosswalk resulted in the shortest crossing decision time,the highest comprehensibility,and the highest perceived safety scores.This study provides guidelines for the design of eHMIs and demonstrates that AR eHMIs based on an intelligent vehicle infrastructure cooperative system,can effectively address the one-to-many interaction problem.展开更多
The successful deployment of autonomous vehicles(AVs)relies heavily on their ability to interact safely and effectively with other road users.External human–machine interfaces(eHMIs)have emerged as critical component...The successful deployment of autonomous vehicles(AVs)relies heavily on their ability to interact safely and effectively with other road users.External human–machine interfaces(eHMIs)have emerged as critical components in facilitating these interactions.Rigorous evaluation and testing of eHMIs are essential for realizing their intended safety and communication benefits.This study provides a comprehensive review of current eHMI research,focusing on their impact on road users’behavior and perceptions,as well as the methods used for evaluation.Key behavioral factors—such as eHMI modality,information type,location,vehicle kinematics,traffic environment,and user characteristics—are systematically reviewed and summarized.The influence of eHMIs on user perceptions is also explored through indicators such as perceived safety,comprehensibility,trust,cognitive load,and user experience.Despite notable advancements,several critical research gaps remain underexplored.Most studies focus on one-toone interactions,neglecting the complexities of mixed-traffic environments involving AVs,conventional human-driven vehicles,pedestrians,and cyclists.Current evaluation methods largely rely on virtual reality and Wizard-of-Oz experiments,which may fail to fully capture real-world dynamics.Additionally,subjective questionnaires,which are often used in these studies,do not guarantee high reproducibility of findings.Moreover,insufficient attention has been given to the synchronization of eHMI signals with vehicle kinematics.Furthermore,the absence of standardized evaluation frameworks limits cross-study comparability and the development of universally applicable eHMI solutions.To address these challenges,future research should prioritize the integration of naturalistic traffic scenarios,the adoption of objective and reproducible evaluation methods,the exploration of multimodal eHMI designs,and the development of standardized assessment protocols.These efforts are crucial for improving AV communication with diverse road users and ensuring safety in increasingly complex traffic ecosystems.展开更多
Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch ...Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively. The average friction coefficients of TiAISiN coat- ing against 2Crl2Ni4Mo3VNbN steel are 0.70 （sliding speed 50 m/rain）, 0.63 （sliding speed 100 m/min）, and 0.81 （sliding speed 150 m/min）. The elements diffusion was analyzed by EDS. A1 and Si element of coating material dif- fuse to the steel disc, except Ti element. The oxidation decreases with the increase of sliding speed, but the adhesion increases with the increase of sliding speed. More A1 element diffuses to the steel disc at the high sliding speed, but the diffusion of Si element keeps almost constant at dlfferent sliding speeds.展开更多
In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the...In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the yarn is cubic B-spline curve,is proposed in this paper.With this model,the 3D simulation of the loop and of the basic structures of the knitted fabric is realized by using Virtual Reality Modeling Language(VRML).The virtual simulation scene is suitable for network transmission with freely available VRML browsers and can be translated,scaled and rotated quite arbitrarily.By using Java and External Authoring Interface(EAI)technology,the web-based interactive simulation platform of weft knitted fabric is established.The user can input type of structures,basic fabric parameters,and yarn colors interactively to obtain a more realistic simulation result in real-time.A new approach is provided to imitate the knitted fabric 3D appearance on network.展开更多
Currently,the mainstream vector network analyzer employs embedded computer module with a digital intermediate frequency(IF)board to form a high performance windows platform.Under this structure,the vector network anal...Currently,the mainstream vector network analyzer employs embedded computer module with a digital intermediate frequency(IF)board to form a high performance windows platform.Under this structure,the vector network analyzer needs a powerful encoding system to arbitrate the bus acquirement,which is usually realized by field-programmable gate array(FPGA)chip.The paper explores the shared bus design method of the digital signal processing(DSP)board in network analyzer.Firsty,it puts an emphasis on the system structure,and then the shared bus communication method is described in detail;Finally,the advantages of the shared bus communication mechanism are summanzed.展开更多
基金supported in part by the Natural Science Foundation of China under Grant 52272417in part by the Science and Technology Development Project of Jilin Province under Grant 20230301008ZD.
文摘External human–machine interfaces(eHMIs)of highly automated vehicles(HAVs)have been developed to communicate vehicle intentions to pedestrians and other road users.This study conducted an online experiment with 33 participants to investigate the impact of a novel HAV’s eHMI of augmented reality(AR)crosswalks on pedestrian crossings using virtual simulation scenario videos and questionnaires.To verify the effectiveness of the AR crosswalk,comparative analyses were performed on eHMIs across 5 modalities:baseline,pedestrian silhouette,virtual eyes,AR headlight,and AR crosswalk,in conjunction with 2 vehicle physical modes(yielding and non-yielding).Metrics used in the study included crossing percentages before the HAV passed,crossing decision time,comprehensibility,and perceived safety.The results indicated that for yielding vehicles,the AR crosswalk resulted in the shortest crossing decision time,the highest comprehensibility,and the highest perceived safety scores.This study provides guidelines for the design of eHMIs and demonstrates that AR eHMIs based on an intelligent vehicle infrastructure cooperative system,can effectively address the one-to-many interaction problem.
基金supported by the National Natural Science Foundation of China(Nos.52472360,72101128,and 72471070)the China Postdoctoral Science Foundation(No.2023M730560).
文摘The successful deployment of autonomous vehicles(AVs)relies heavily on their ability to interact safely and effectively with other road users.External human–machine interfaces(eHMIs)have emerged as critical components in facilitating these interactions.Rigorous evaluation and testing of eHMIs are essential for realizing their intended safety and communication benefits.This study provides a comprehensive review of current eHMI research,focusing on their impact on road users’behavior and perceptions,as well as the methods used for evaluation.Key behavioral factors—such as eHMI modality,information type,location,vehicle kinematics,traffic environment,and user characteristics—are systematically reviewed and summarized.The influence of eHMIs on user perceptions is also explored through indicators such as perceived safety,comprehensibility,trust,cognitive load,and user experience.Despite notable advancements,several critical research gaps remain underexplored.Most studies focus on one-toone interactions,neglecting the complexities of mixed-traffic environments involving AVs,conventional human-driven vehicles,pedestrians,and cyclists.Current evaluation methods largely rely on virtual reality and Wizard-of-Oz experiments,which may fail to fully capture real-world dynamics.Additionally,subjective questionnaires,which are often used in these studies,do not guarantee high reproducibility of findings.Moreover,insufficient attention has been given to the synchronization of eHMI signals with vehicle kinematics.Furthermore,the absence of standardized evaluation frameworks limits cross-study comparability and the development of universally applicable eHMI solutions.To address these challenges,future research should prioritize the integration of naturalistic traffic scenarios,the adoption of objective and reproducible evaluation methods,the exploration of multimodal eHMI designs,and the development of standardized assessment protocols.These efforts are crucial for improving AV communication with diverse road users and ensuring safety in increasingly complex traffic ecosystems.
基金Supported by China Postdoctoral Science Foundation(No. 20110490380 and No. 20110490383)Dongfang Turbine Co, Ltd (No. 2011GZ011)State Key Laboratory of Tribology, Tsinghua University (No. SKLT10A01)
文摘Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively. The average friction coefficients of TiAISiN coat- ing against 2Crl2Ni4Mo3VNbN steel are 0.70 （sliding speed 50 m/rain）, 0.63 （sliding speed 100 m/min）, and 0.81 （sliding speed 150 m/min）. The elements diffusion was analyzed by EDS. A1 and Si element of coating material dif- fuse to the steel disc, except Ti element. The oxidation decreases with the increase of sliding speed, but the adhesion increases with the increase of sliding speed. More A1 element diffuses to the steel disc at the high sliding speed, but the diffusion of Si element keeps almost constant at dlfferent sliding speeds.
基金Jiangsu Natural Science Foundation of University,China(No.07KJD540178)Foundation of Nantong Science and Technology of China(No.K2007009)Graduate Innovation Project of Nantong University,China(No.YKC09056)
文摘In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the yarn is cubic B-spline curve,is proposed in this paper.With this model,the 3D simulation of the loop and of the basic structures of the knitted fabric is realized by using Virtual Reality Modeling Language(VRML).The virtual simulation scene is suitable for network transmission with freely available VRML browsers and can be translated,scaled and rotated quite arbitrarily.By using Java and External Authoring Interface(EAI)technology,the web-based interactive simulation platform of weft knitted fabric is established.The user can input type of structures,basic fabric parameters,and yarn colors interactively to obtain a more realistic simulation result in real-time.A new approach is provided to imitate the knitted fabric 3D appearance on network.
文摘Currently,the mainstream vector network analyzer employs embedded computer module with a digital intermediate frequency(IF)board to form a high performance windows platform.Under this structure,the vector network analyzer needs a powerful encoding system to arbitrate the bus acquirement,which is usually realized by field-programmable gate array(FPGA)chip.The paper explores the shared bus design method of the digital signal processing(DSP)board in network analyzer.Firsty,it puts an emphasis on the system structure,and then the shared bus communication method is described in detail;Finally,the advantages of the shared bus communication mechanism are summanzed.
