Power line(PL)interference is one significant artifact in electrocardiography(ECG)that needs to be reduced to ensure accurate recording of cardiac signals.Because PL interference is non-stationary and has varying freq...Power line(PL)interference is one significant artifact in electrocardiography(ECG)that needs to be reduced to ensure accurate recording of cardiac signals.Because PL interference is non-stationary and has varying frequency,phase,and amplitude in ECG measurement,adaptive techniques are often necessary to track and cancel the interference.In this paper we present a phase-locked loop(PLL)-based adaptive filter to cancel PL interference.The PLL obtains the reference signal that is fed into the adaptive filter to remove the PL interference at the central frequency of 50 Hz.It is found that the technique can effectively cancel PL interference in real ECG signals and,when compared with some existing techniques such as least mean squares(LMS)adaptive filter,the new technique produces better results in terms of signal-to-interference ratio(SIR).展开更多
针对洁净板生产线传统调试过程中存在的周期长、成本高、可靠性低等问题,提出了一种基于数字孪生理念的虚拟调试系统架构。通过使用Visual Components构建高保真三维仿真模型,结合Siemens TIA Portal开发模块化控制逻辑,并利用KEP Serve...针对洁净板生产线传统调试过程中存在的周期长、成本高、可靠性低等问题,提出了一种基于数字孪生理念的虚拟调试系统架构。通过使用Visual Components构建高保真三维仿真模型,结合Siemens TIA Portal开发模块化控制逻辑,并利用KEP Server EX 6搭建OPC UA与TCP/IP混合通信网络,实现了物理仿真层、逻辑控制层和数据交互层的协同集成。以岩棉填充工位为例,进行了端到端信号链路验证与全流程物料流仿真。通过对比仿真与实物机器人的运动数据,验证了该系统在关节角度和角速度方面的平均误差小于0.5°,且误差分布在±0.5°范围内的概率达到97.3%。结果表明,所构建的虚拟调试系统具有较高的运动学精度和可靠性,可为洁净板生产线提供低成本、高效率的数字化预验证平台。展开更多
电缆隧道封闭狭长,存在重复布设的电缆架和相似的场景纹理,属于退化场景.针对该场景,提出了1种基于点线特征融合的视觉惯导SLAM(simultaneous localization and mapping)算法.该算法通过长度抑制和短线拟合来改进高维线特征,使其能够更...电缆隧道封闭狭长,存在重复布设的电缆架和相似的场景纹理,属于退化场景.针对该场景,提出了1种基于点线特征融合的视觉惯导SLAM(simultaneous localization and mapping)算法.该算法通过长度抑制和短线拟合来改进高维线特征,使其能够更有效地描述结构化显著的隧道场景.此外,针对电缆隧道中特征相似导致的回环检测失败问题,引入具有高效识别和精确位姿估计的ArUco标记,限定回环发生区域,并利用最小化位姿变换筛选最佳回环帧,从而提升回环检测的准确度和定位精度.最后,在电缆隧道内采集数据集并进行实验验证.结果表明,相对于VINS–Mono(visual inertial system–Mono),所提算法的绝对轨迹精度平均提升了69.73%,满足了电缆隧道巡检的应用需求.展开更多
柔性软开关(soft open point, SOP)能够实现配电网的柔性互联与潮流的动态调节,从而优化配电资源的配置与调度。换流器可以在故障时输出正负序电流来提供电压支撑并提高自身的故障穿越能力,从而改善不对称接地故障的负载电压。然而采用...柔性软开关(soft open point, SOP)能够实现配电网的柔性互联与潮流的动态调节,从而优化配电资源的配置与调度。换流器可以在故障时输出正负序电流来提供电压支撑并提高自身的故障穿越能力,从而改善不对称接地故障的负载电压。然而采用开环计算的方案易受实际工况影响,采用传统负序电压闭环的支撑效果较差。因此文中在传统负序电压外环的基础上进行改进,控制负序电流的幅值以抑制负序电压,控制负序电流的相位以优化抑制效果。为提高逆变器容量利用率并限制有功波动,文中提出正负序电流限幅的综合方案,并通过PSCAD仿真软件依据实际配电网参数搭建短路工况进行仿真。结果验证该控制策略可以有效改善故障时的电压表现,提高逆变器低压穿越能力,具有更高的实际可应用性。展开更多
文摘Power line(PL)interference is one significant artifact in electrocardiography(ECG)that needs to be reduced to ensure accurate recording of cardiac signals.Because PL interference is non-stationary and has varying frequency,phase,and amplitude in ECG measurement,adaptive techniques are often necessary to track and cancel the interference.In this paper we present a phase-locked loop(PLL)-based adaptive filter to cancel PL interference.The PLL obtains the reference signal that is fed into the adaptive filter to remove the PL interference at the central frequency of 50 Hz.It is found that the technique can effectively cancel PL interference in real ECG signals and,when compared with some existing techniques such as least mean squares(LMS)adaptive filter,the new technique produces better results in terms of signal-to-interference ratio(SIR).
文摘针对洁净板生产线传统调试过程中存在的周期长、成本高、可靠性低等问题,提出了一种基于数字孪生理念的虚拟调试系统架构。通过使用Visual Components构建高保真三维仿真模型,结合Siemens TIA Portal开发模块化控制逻辑,并利用KEP Server EX 6搭建OPC UA与TCP/IP混合通信网络,实现了物理仿真层、逻辑控制层和数据交互层的协同集成。以岩棉填充工位为例,进行了端到端信号链路验证与全流程物料流仿真。通过对比仿真与实物机器人的运动数据,验证了该系统在关节角度和角速度方面的平均误差小于0.5°,且误差分布在±0.5°范围内的概率达到97.3%。结果表明,所构建的虚拟调试系统具有较高的运动学精度和可靠性,可为洁净板生产线提供低成本、高效率的数字化预验证平台。
文摘柔性软开关(soft open point, SOP)能够实现配电网的柔性互联与潮流的动态调节,从而优化配电资源的配置与调度。换流器可以在故障时输出正负序电流来提供电压支撑并提高自身的故障穿越能力,从而改善不对称接地故障的负载电压。然而采用开环计算的方案易受实际工况影响,采用传统负序电压闭环的支撑效果较差。因此文中在传统负序电压外环的基础上进行改进,控制负序电流的幅值以抑制负序电压,控制负序电流的相位以优化抑制效果。为提高逆变器容量利用率并限制有功波动,文中提出正负序电流限幅的综合方案,并通过PSCAD仿真软件依据实际配电网参数搭建短路工况进行仿真。结果验证该控制策略可以有效改善故障时的电压表现,提高逆变器低压穿越能力,具有更高的实际可应用性。
