A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and...A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.展开更多
处于改建阶段的智能变电站采样模式复杂,继电保护装置难以发现采样回路轻微异常,导致回路隐患暴露时间严重滞后。针对上述问题,分析改建时期智能变电站的采样模式和二次设备配置情况,提出基于同源录波数据比对的继电保护采样回路异常检...处于改建阶段的智能变电站采样模式复杂,继电保护装置难以发现采样回路轻微异常,导致回路隐患暴露时间严重滞后。针对上述问题,分析改建时期智能变电站的采样模式和二次设备配置情况,提出基于同源录波数据比对的继电保护采样回路异常检测方法。首先,利用双向编码器表征(bidirectional encoder representations from transformers,BERT)语言模型与余弦相似度算法,实现同源录波数据的通道匹配。然后,利用重采样技术和曼哈顿距离完成波形的采样频率统一与时域对齐。最后,基于动态时间规整(dynamic time warping,DTW)算法提出改进算法,并结合采样点偏移量共同设置采样回路的异常判据。算例分析表明,该方法可以完成录波数据的同源通道匹配,实现波形的一致性对齐,并且相比于传统DTW算法,改进DTW算法对异常状态识别的灵敏性和准确性更高。根据异常判据能够有效检测继电保护采样回路的异常状态,确保了智能变电站的安全可靠运行。展开更多
磷酸铁锂电池热失控是当前大规模电化学储能系统安全运行面临的主要挑战之一。该文提出了一种用于热失控过程中方形铝壳磷酸铁锂电池内部状态监测的原位超声透射方法,并结合温度、电压、电流、表面形变等多参数检测技术,构建了电池热失...磷酸铁锂电池热失控是当前大规模电化学储能系统安全运行面临的主要挑战之一。该文提出了一种用于热失控过程中方形铝壳磷酸铁锂电池内部状态监测的原位超声透射方法,并结合温度、电压、电流、表面形变等多参数检测技术,构建了电池热失控内-外参量综合测试系统。研究了电池在不同工况下内外参量变化特性,讨论了超声信号对电池内部演变的响应机制,实现了不同工况下电池内部状态的精确监测。结果表明,超声信号强度(U_(rms))和超声飞行时间(time of flight,TOF)能够有效表征电池内部状态的变化,其中U_(rms)对电池温度和荷电状态(state-of-charge,SOC)的变化更为敏感。电池过充会显著增强超声信号衰减效果,且信号被噪声淹没的时间节点远早于防爆阀开启时间,表明超声信号可作为电池过充热失控的早期预警指标。在此基础上,提出了基于改进马田系统的电池过充热失控预警算法,提前30 min预测电池防爆阀的开启。该研究工作对于深入认识储能电池热失控的时空发展特性,提升热失控的早期预警技术具有重要意义。展开更多
基金Project(51175159)supported by the National Natural Science Foundation of ChinaProject(2013WK3024)supported by the Science andTechnology Planning Program of Hunan Province,ChinaProject(CX2013B146)supported by the Hunan Provincial InnovationFoundation for Postgraduate,China
文摘A technology for unintended lane departure warning was proposed. As crucial information, lane boundaries were detected based on principal component analysis of grayscale distribution in search bars of given number and then each search bar was tracked using Kalman filter between frames. The lane detection performance was evaluated and demonstrated in ways of receiver operating characteristic, dice similarity coefficient and real-time performance. For lane departure detection, a lane departure risk evaluation model based on lasting time and frequency was effectively executed on the ARM-based platform. Experimental results indicate that the algorithm generates satisfactory lane detection results under different traffic and lighting conditions, and the proposed warning mechanism sends effective warning signals, avoiding most false warning.
文摘处于改建阶段的智能变电站采样模式复杂,继电保护装置难以发现采样回路轻微异常,导致回路隐患暴露时间严重滞后。针对上述问题,分析改建时期智能变电站的采样模式和二次设备配置情况,提出基于同源录波数据比对的继电保护采样回路异常检测方法。首先,利用双向编码器表征(bidirectional encoder representations from transformers,BERT)语言模型与余弦相似度算法,实现同源录波数据的通道匹配。然后,利用重采样技术和曼哈顿距离完成波形的采样频率统一与时域对齐。最后,基于动态时间规整(dynamic time warping,DTW)算法提出改进算法,并结合采样点偏移量共同设置采样回路的异常判据。算例分析表明,该方法可以完成录波数据的同源通道匹配,实现波形的一致性对齐,并且相比于传统DTW算法,改进DTW算法对异常状态识别的灵敏性和准确性更高。根据异常判据能够有效检测继电保护采样回路的异常状态,确保了智能变电站的安全可靠运行。
文摘磷酸铁锂电池热失控是当前大规模电化学储能系统安全运行面临的主要挑战之一。该文提出了一种用于热失控过程中方形铝壳磷酸铁锂电池内部状态监测的原位超声透射方法,并结合温度、电压、电流、表面形变等多参数检测技术,构建了电池热失控内-外参量综合测试系统。研究了电池在不同工况下内外参量变化特性,讨论了超声信号对电池内部演变的响应机制,实现了不同工况下电池内部状态的精确监测。结果表明,超声信号强度(U_(rms))和超声飞行时间(time of flight,TOF)能够有效表征电池内部状态的变化,其中U_(rms)对电池温度和荷电状态(state-of-charge,SOC)的变化更为敏感。电池过充会显著增强超声信号衰减效果,且信号被噪声淹没的时间节点远早于防爆阀开启时间,表明超声信号可作为电池过充热失控的早期预警指标。在此基础上,提出了基于改进马田系统的电池过充热失控预警算法,提前30 min预测电池防爆阀的开启。该研究工作对于深入认识储能电池热失控的时空发展特性,提升热失控的早期预警技术具有重要意义。
