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芯板变形预补偿数学模型研究
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作者 杨海云 陈笑林 +1 位作者 卢建文 郑永辉 《印制电路信息》 2014年第4期200-209,共10页
文章通过对PCB板生产过程中板变形影响因素进行具体分析和研究,在诸多板变形的影响因素中归纳出以下四个主要影响因子:即层数因子(L)、芯板铜厚因子(T)、压板厚度因子(H)、层间介质因子(P),并分别对以上四个主要影响因子与板变形的影响... 文章通过对PCB板生产过程中板变形影响因素进行具体分析和研究,在诸多板变形的影响因素中归纳出以下四个主要影响因子:即层数因子(L)、芯板铜厚因子(T)、压板厚度因子(H)、层间介质因子(P),并分别对以上四个主要影响因子与板变形的影响关系进行了大量的生产数据收集。根据板变形数据库建立芯板变形预补偿数学模型,利用预补偿数学模型来计算内层菲林的预补偿值,通过实例应用和推广,有效提升了公司芯板预补偿系数的合格率,减少了由于补偿不合理而产生的内短、层偏报废。 展开更多
关键词 补偿系数 板变形 补偿数学模型 热膨胀系数
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Case study on the mechanics of NPR anchor cable compensation for large deformation tunnel in soft rock in the Transverse Mountain area,China
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作者 LI Yong ZHENG Jing +3 位作者 HUO Shu-sen WANG Feng-nian HE Man-chao TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2054-2069,共16页
A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri... A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas. 展开更多
关键词 soft rock large deformation NPR anchor cable physical model numerical simulation compensation mechanics
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Adaptive friction compensation for large diameter electro-hydraulic proportional valve cores based on LuGre 被引量:2
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作者 孔祥东 Song Yu +2 位作者 Ai Chao Li Yanpeng Tian Dezhi 《High Technology Letters》 EI CAS 2015年第4期371-378,共8页
This paper presents an adaptive friction compensation method based on LuGre model for large diameter electric-hydraulic proportional valves in which the valve core contains friction.A mathematic model of the electric-... This paper presents an adaptive friction compensation method based on LuGre model for large diameter electric-hydraulic proportional valves in which the valve core contains friction.A mathematic model of the electric-hydraulic proportional valve is established,and the friction characteristics are described based on the LuGre model.The global asymptotic stability of the control system with the adaptive friction compensation controller is guaranteed over Lyapunov theorem.The adaptive compensation of the friction on LuGre friction model is verified by simulation and experiment.The steady-state error is about [-4.23 × 10^(-5)m,5.91 × 10^(-5)m]and[-2.5 × 10^(-4)m,2.6 ×10^(-4) m] on simulation and experiment,the position tracking accuracy is higher,and the lag time of the main valve through the dead zone is shorter.The result proves that the adaptive friction compensation method can effectively compensate for the negative effects of nonlinear friction. 展开更多
关键词 electric-hydraulic proportional valve pilot stage LuGre adaptive friction com- pensation experimental identification
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激光自外差相干测量中分布反馈半导体激光器电流调谐非线性的补偿方法 被引量:5
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作者 安颖 杜振辉 +1 位作者 刘景旺 徐可欣 《物理学报》 SCIE EI CAS CSCD 北大核心 2012年第3期183-188,共6页
半导体激光器的电流调谐非线性对自外差相干测量的精度影响很大.研究了分布反馈半导体(DFB)激光器的电流调谐特性,据此提出一种数学模型补偿方法.利用己知光程差下的差拍频率,建立了动态调频系数的数学模型.以此模型对DFB激光器的电流... 半导体激光器的电流调谐非线性对自外差相干测量的精度影响很大.研究了分布反馈半导体(DFB)激光器的电流调谐特性,据此提出一种数学模型补偿方法.利用己知光程差下的差拍频率,建立了动态调频系数的数学模型.以此模型对DFB激光器的电流调谐非线性进行补偿,可以将差拍信号频率预测值的相对误差减小约3%,提高了系统的测量精度.数学模型补偿方法简化了测量系统的结构,适用于高精度的电流调谐激光在线测量系统. 展开更多
关键词 自外差相干测量 分布反馈半导体激光器 调谐非线性 数学模型补偿
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