For strapdown stabilized platform used in automatic vertical drilling system,a new dynamic measurement algorithm based on three-axis accelerometer and three-axis fluxgate measurement signals is proposed and simulated ...For strapdown stabilized platform used in automatic vertical drilling system,a new dynamic measurement algorithm based on three-axis accelerometer and three-axis fluxgate measurement signals is proposed and simulated under the condition of small inclination dynamic rotation.The error compensation algorithm is also proposed.The bench test of strapdown stabilized platform is designed and carried out.The results show that:When the azimuth angle is the same,the larger the inclination angle is,the greater the error of the measurement results will be.When the inclination angle is the same,the measurement error is the largest when the azimuth angle is 90°and 270°,and the measurement error curve presents a sinusoidal change with the change of azimuth angle.After the error function compensation,the error curve between the calculation results and the true value is basically not affected by the inclination angle and the azimuth angle,and the calculation accuracy is signifi cantly improved.Under the random rotating speed of 0-180 rpm,the minimum error of the measured well inclination value was no more than 0.03°and the maximum was no more than 1.58°.The feasibility of the proposed dynamic azimuth measurement algorithm is verifi ed.This article provides a technical reference for the strapdown automatic drilling system.展开更多
Purpose–To support the standardized evaluation of bicyclist automatic emergency braking(AEB)systems,test scenarios,test procedures and test system hardware and software tools have been investigated and developed by t...Purpose–To support the standardized evaluation of bicyclist automatic emergency braking(AEB)systems,test scenarios,test procedures and test system hardware and software tools have been investigated and developed by the Transportation Active Safety Institute(TASI)at Indiana University-Purdue University Indianapolis.This paper aims to focus on the development of test scenarios and bicyclist surrogate for evaluating vehicle–bicyclist AEB systems.Design/methodology/approach–The harmonized general estimates system(GES)/FARS 2010-2011 crash data and TASI 110-car naturalistic driving data(NDD)are used to determine the crash geometries and environmental factors of crash scenarios including lighting conditions,vehicle speeds,bicyclist speeds,etc.A surrogate bicyclist including a bicycle rider and a bicycle surrogate is designed to match the visual and radar characteristics of bicyclists in the USA.A bicycle target is designed with both leg pedaling and wheel rotation to produce proper micro-Doppler features and generate realistic motion for camera-based AEB systems.Findings–Based on the analysis of the harmonized GES/FARS crash data,five crash scenarios are recommended for performance testing of bicyclist AEB systems.Combined with TASI 110-car naturalistic driving data,the crash environmental factors including lighting conditions,obscuring objects,vehicle speed and bicyclist speed are determined.The surrogate bicyclist was designed to represent the visual and radar characteristics of the real bicyclists in the USA.The height of the bicycle rider mannequin is 173 cm,representing the weighted height of 50th percentile US male and female adults.The size and shape of the surrogate bicycle were determined as 26-inch wheel and mountain/road bicycle frame,respectively.Both leg pedaling motion and wheel rotation are suggested to produce proper micro-Doppler features and support the camera-based AEB systems.Originality/value–The results have demonstrated that the developed scenarios,test procedures and bicyclist surrogate will provide effective objective methods and necessary hardware and software tools for the evaluation and validation of bicyclist AEB systems.This is crucial for the development of advanced driver assistance systems.展开更多
题目自动生成(Automatic Item Generation,AIG)技术通过自动化生成测验题目,旨在解决心理与教育测验中题目开发成本高、效率低、维护困难和安全风险等问题。该技术经历了从规则驱动方法到大语言模型(Large Language Model,LLM)的演进历...题目自动生成(Automatic Item Generation,AIG)技术通过自动化生成测验题目,旨在解决心理与教育测验中题目开发成本高、效率低、维护困难和安全风险等问题。该技术经历了从规则驱动方法到大语言模型(Large Language Model,LLM)的演进历程,虽显著提升了生成效率与内容多样性,但在应用过程中面临专业知识表达准确性、文化公平性与构念效度、多模态内容生成、开放性题目发展、智能化质量控制、资源环境适应及技术可访问性等现实挑战。针对这些挑战,有效应对策略包括检索增强生成技术和多模态生成模型应用、多阶段心理测量学验证、云算力资源整合及用户友好型系统开发等。这些方法为提升自动生成题目的科学性与实用性提供了可行路径。展开更多
针对集成电路中差分信号的差分电压和共模电压采用固定输出状态测试,信号的频率采用脉冲计数法测试,由于差分电压与频率需分别测试,导致测试效率偏低,且操作较繁琐、人为引入的不确定性较大,测试方法与数据不可溯源,不适合批量筛选测试...针对集成电路中差分信号的差分电压和共模电压采用固定输出状态测试,信号的频率采用脉冲计数法测试,由于差分电压与频率需分别测试,导致测试效率偏低,且操作较繁琐、人为引入的不确定性较大,测试方法与数据不可溯源,不适合批量筛选测试。为此,提出了一种基于自动化测试系统(Automatic Test Equipment,ATE)中时间测量单元(Time Measurement Unit,TMU)的扫描测试方法,TMU通过测量信号相同幅值两点间的时间差计算得到频率,同时采用扫描法得到差分信号幅值的极值,进而得到差分电压和共模电压。通过对时钟恢复器的测试实验,验证了测试结果与差分信号的实际波形一致,满足器件的性能指标,表明该测试方法稳定可靠、效率高、自动化程度高、可溯源性强,可广泛应用于集成电路的批量测试中。展开更多
基金The financial supports from National key plan project for research and development of China (2019YFA0708300) and (2023YFC3009200)。
文摘For strapdown stabilized platform used in automatic vertical drilling system,a new dynamic measurement algorithm based on three-axis accelerometer and three-axis fluxgate measurement signals is proposed and simulated under the condition of small inclination dynamic rotation.The error compensation algorithm is also proposed.The bench test of strapdown stabilized platform is designed and carried out.The results show that:When the azimuth angle is the same,the larger the inclination angle is,the greater the error of the measurement results will be.When the inclination angle is the same,the measurement error is the largest when the azimuth angle is 90°and 270°,and the measurement error curve presents a sinusoidal change with the change of azimuth angle.After the error function compensation,the error curve between the calculation results and the true value is basically not affected by the inclination angle and the azimuth angle,and the calculation accuracy is signifi cantly improved.Under the random rotating speed of 0-180 rpm,the minimum error of the measured well inclination value was no more than 0.03°and the maximum was no more than 1.58°.The feasibility of the proposed dynamic azimuth measurement algorithm is verifi ed.This article provides a technical reference for the strapdown automatic drilling system.
文摘Purpose–To support the standardized evaluation of bicyclist automatic emergency braking(AEB)systems,test scenarios,test procedures and test system hardware and software tools have been investigated and developed by the Transportation Active Safety Institute(TASI)at Indiana University-Purdue University Indianapolis.This paper aims to focus on the development of test scenarios and bicyclist surrogate for evaluating vehicle–bicyclist AEB systems.Design/methodology/approach–The harmonized general estimates system(GES)/FARS 2010-2011 crash data and TASI 110-car naturalistic driving data(NDD)are used to determine the crash geometries and environmental factors of crash scenarios including lighting conditions,vehicle speeds,bicyclist speeds,etc.A surrogate bicyclist including a bicycle rider and a bicycle surrogate is designed to match the visual and radar characteristics of bicyclists in the USA.A bicycle target is designed with both leg pedaling and wheel rotation to produce proper micro-Doppler features and generate realistic motion for camera-based AEB systems.Findings–Based on the analysis of the harmonized GES/FARS crash data,five crash scenarios are recommended for performance testing of bicyclist AEB systems.Combined with TASI 110-car naturalistic driving data,the crash environmental factors including lighting conditions,obscuring objects,vehicle speed and bicyclist speed are determined.The surrogate bicyclist was designed to represent the visual and radar characteristics of the real bicyclists in the USA.The height of the bicycle rider mannequin is 173 cm,representing the weighted height of 50th percentile US male and female adults.The size and shape of the surrogate bicycle were determined as 26-inch wheel and mountain/road bicycle frame,respectively.Both leg pedaling motion and wheel rotation are suggested to produce proper micro-Doppler features and support the camera-based AEB systems.Originality/value–The results have demonstrated that the developed scenarios,test procedures and bicyclist surrogate will provide effective objective methods and necessary hardware and software tools for the evaluation and validation of bicyclist AEB systems.This is crucial for the development of advanced driver assistance systems.
文摘题目自动生成(Automatic Item Generation,AIG)技术通过自动化生成测验题目,旨在解决心理与教育测验中题目开发成本高、效率低、维护困难和安全风险等问题。该技术经历了从规则驱动方法到大语言模型(Large Language Model,LLM)的演进历程,虽显著提升了生成效率与内容多样性,但在应用过程中面临专业知识表达准确性、文化公平性与构念效度、多模态内容生成、开放性题目发展、智能化质量控制、资源环境适应及技术可访问性等现实挑战。针对这些挑战,有效应对策略包括检索增强生成技术和多模态生成模型应用、多阶段心理测量学验证、云算力资源整合及用户友好型系统开发等。这些方法为提升自动生成题目的科学性与实用性提供了可行路径。
文摘针对集成电路中差分信号的差分电压和共模电压采用固定输出状态测试,信号的频率采用脉冲计数法测试,由于差分电压与频率需分别测试,导致测试效率偏低,且操作较繁琐、人为引入的不确定性较大,测试方法与数据不可溯源,不适合批量筛选测试。为此,提出了一种基于自动化测试系统(Automatic Test Equipment,ATE)中时间测量单元(Time Measurement Unit,TMU)的扫描测试方法,TMU通过测量信号相同幅值两点间的时间差计算得到频率,同时采用扫描法得到差分信号幅值的极值,进而得到差分电压和共模电压。通过对时钟恢复器的测试实验,验证了测试结果与差分信号的实际波形一致,满足器件的性能指标,表明该测试方法稳定可靠、效率高、自动化程度高、可溯源性强,可广泛应用于集成电路的批量测试中。
