A signal optimization model for roundabout was control concept were used to eliminate the conflict points proposed based on dual-ring scheme and two stop lines for left turns and weaving sections at a roundabout. A cy...A signal optimization model for roundabout was control concept were used to eliminate the conflict points proposed based on dual-ring scheme and two stop lines for left turns and weaving sections at a roundabout. A cycle length minimization problem was considered to generate optimal signal timings for roundabout, and a set of constraints to ensure feasibility and safety of the resulting optimal signal settings were proposed. Extensive experimental analyses in comparison with signalized intersection reveal that the proposed model is quite promising for application in design of roundabout signals, and the minimum cycle length can decrease from 186 s to 79 s while the capacity increases from 8 682 pcu/h to 9 011 pcu/h under high demand scenario. Sensitivity analysis with respect to the system performance show that the lane assignment plan, number of circulatory lanes and left turn ratio are three critical factors which have dominate impacts on performance of signalized roundabout展开更多
针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自...针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自抗扰控制,速度环采用传统的自抗扰控制。电流环采用一种改进的谐振扩张状态观测器,将观测电流作为谐振控制器的输入,令谐振控制器的输出直接作用到电流环输出,从而降低了谐振电流环设计的复杂性。双环自抗扰谐振控制器保留了谐振控制器抑制特定频率谐波电流的特性,同时优化了系统的超调量与调节时间,有效提升了谐振控制系统的动态性能。仿真结果验证DLADRC系统的有效性。展开更多
提出了一种基于射频调制-解调的光纤环干涉仪传感技术,用于双参量高精度无串扰传感。在低调制频率下光纤环干涉仪(Fiber Optic Ring Interferometer,FORI)对温度变化不敏感,而对损耗变化表现出灵活的可调谐灵敏度,其线性透射率灵敏度为0...提出了一种基于射频调制-解调的光纤环干涉仪传感技术,用于双参量高精度无串扰传感。在低调制频率下光纤环干涉仪(Fiber Optic Ring Interferometer,FORI)对温度变化不敏感,而对损耗变化表现出灵活的可调谐灵敏度,其线性透射率灵敏度为0.282 rad。通过选择特定的调制频率,可实现损耗的线性传感或最大灵敏度传感。在高调制频率下,利用温度引起的频移累积效应,通过追踪零相移点频率实现温度解调,灵敏度达-17.47 kHz/℃。实验结果表明,所提方法成功实现了透射率和温度的双参量无串扰同时测量。这种基于射频调制-解调的FORI传感技术展现了在多参量传感领域的应用潜力,为高精度、多功能光纤传感系统的发展提供了新的思路。展开更多
基金Project(51178345) supported by the National Natural Science Foundation of ChinaProject(2011AA110305) supported by the National High Technology Research and Development Program of ChinaProject supported by the Program for Young Excellent Talents in Tongji University, China
文摘A signal optimization model for roundabout was control concept were used to eliminate the conflict points proposed based on dual-ring scheme and two stop lines for left turns and weaving sections at a roundabout. A cycle length minimization problem was considered to generate optimal signal timings for roundabout, and a set of constraints to ensure feasibility and safety of the resulting optimal signal settings were proposed. Extensive experimental analyses in comparison with signalized intersection reveal that the proposed model is quite promising for application in design of roundabout signals, and the minimum cycle length can decrease from 186 s to 79 s while the capacity increases from 8 682 pcu/h to 9 011 pcu/h under high demand scenario. Sensitivity analysis with respect to the system performance show that the lane assignment plan, number of circulatory lanes and left turn ratio are three critical factors which have dominate impacts on performance of signalized roundabout
文摘针对传统谐振控制器与PI控制器并联(PIR)无法克服积分环节饱和等因素引起的系统动态过程中超调震荡问题,提出了一种改进双环自抗扰谐振控制器(dual-loop active disturbance rejection control,DLADRC)。DLADRC速度环与电流环均采用自抗扰控制,速度环采用传统的自抗扰控制。电流环采用一种改进的谐振扩张状态观测器,将观测电流作为谐振控制器的输入,令谐振控制器的输出直接作用到电流环输出,从而降低了谐振电流环设计的复杂性。双环自抗扰谐振控制器保留了谐振控制器抑制特定频率谐波电流的特性,同时优化了系统的超调量与调节时间,有效提升了谐振控制系统的动态性能。仿真结果验证DLADRC系统的有效性。
