充电截止电压是大多数电动汽车用户充电都会经历的电压点。针对传统安时积分法忽略初始容量误差和电池老化等一系列待优化的问题,提出了双层集成极限学习机(extreme learning machine,ELM)算法,实现锂离子电池充电截止电压下的荷电状态(...充电截止电压是大多数电动汽车用户充电都会经历的电压点。针对传统安时积分法忽略初始容量误差和电池老化等一系列待优化的问题,提出了双层集成极限学习机(extreme learning machine,ELM)算法,实现锂离子电池充电截止电压下的荷电状态(state of charge,SOC)和健康状态(state of health,SOH)联合估计。首先,提取易测的电池健康特征(health indicator,HI),采用集成极限学习机映射HI及充电所需时间与SOH之间的关系。其次,用测得的HI估计难以在线测量的充电所需时间,对充电截止电压下安时积分法的SOC进行在线修正。该方法充分考虑了电动汽车用户初始充电状态的不确定性,指导电动汽车用户合理充电。此外,通过选择合适的集成ELM模型集成度,解决了单个ELM模型输出不稳定的问题。最后,选用NASA和CALCE数据集进行实验验证。验证结果表明,锂离子电池充电截止电压下SOC的估计均方根误差均小于1.5%,集成ELM相比于其他常见算法具有较高的训练、测试精度和较短的预测时间。展开更多
During the period of reconstruction after Yushu Earthquake, a large number of sea-level or lowland workers ascended there and worked at altitudes between 3 750 m and 4 878 m which is a hypoxic environment. To investig...During the period of reconstruction after Yushu Earthquake, a large number of sea-level or lowland workers ascended there and worked at altitudes between 3 750 m and 4 878 m which is a hypoxic environment. To investigate the sleep quality at that altitude, we performed two full polysomnographies （PSGs） in 10 volunteers, who were healthy male workers, aged 31 ：i：6.6, born and living at sea level, without experience of pre-altitude expo- sure. The assessment of subjective sleep quality was performed twice in each volunteer. The first investigations were carried out at sea level in Jinan city （pB=760 torr, 1 torr=133.322 4 Pa）. The second studies were performed at an altitude of 3 750 m （pB=416 tort） in Yushu Jiegu in the same 10 workers after they lived and worked at that alti- tude for 5 months. At sea level, workers presented a normal sleep structure and a higher oxygenation during sleep. However, as compared to sea-level sleep, at 3 750 m, workers had a shorter total sleep time （TST） （p 〈 0.001）, a longer stage 1 non-rapid eye movement （nREM） sleep （p 〈 0.05） and a shorter 3＋4 nREM and rapid eye movement （REM） sleep （p 〈 0.05） with a severe sleep hypoxemia （p 〈 0.01）. Our data suggested that sea-level workers revealed a disturbed sleep and a bad sleep quality with a significant sleep hypoxemia at altitude of 3 750 m. Strengthening the prevention and treatment are thereby sorely necessary.展开更多
文摘充电截止电压是大多数电动汽车用户充电都会经历的电压点。针对传统安时积分法忽略初始容量误差和电池老化等一系列待优化的问题,提出了双层集成极限学习机(extreme learning machine,ELM)算法,实现锂离子电池充电截止电压下的荷电状态(state of charge,SOC)和健康状态(state of health,SOH)联合估计。首先,提取易测的电池健康特征(health indicator,HI),采用集成极限学习机映射HI及充电所需时间与SOH之间的关系。其次,用测得的HI估计难以在线测量的充电所需时间,对充电截止电压下安时积分法的SOC进行在线修正。该方法充分考虑了电动汽车用户初始充电状态的不确定性,指导电动汽车用户合理充电。此外,通过选择合适的集成ELM模型集成度,解决了单个ELM模型输出不稳定的问题。最后,选用NASA和CALCE数据集进行实验验证。验证结果表明,锂离子电池充电截止电压下SOC的估计均方根误差均小于1.5%,集成ELM相比于其他常见算法具有较高的训练、测试精度和较短的预测时间。
基金"973"National Key Basic Research and Develvpment Program(No.2012CB518202)Project of Qinghai Development of Science and Technology(No.2011-N-150)
文摘During the period of reconstruction after Yushu Earthquake, a large number of sea-level or lowland workers ascended there and worked at altitudes between 3 750 m and 4 878 m which is a hypoxic environment. To investigate the sleep quality at that altitude, we performed two full polysomnographies （PSGs） in 10 volunteers, who were healthy male workers, aged 31 ：i：6.6, born and living at sea level, without experience of pre-altitude expo- sure. The assessment of subjective sleep quality was performed twice in each volunteer. The first investigations were carried out at sea level in Jinan city （pB=760 torr, 1 torr=133.322 4 Pa）. The second studies were performed at an altitude of 3 750 m （pB=416 tort） in Yushu Jiegu in the same 10 workers after they lived and worked at that alti- tude for 5 months. At sea level, workers presented a normal sleep structure and a higher oxygenation during sleep. However, as compared to sea-level sleep, at 3 750 m, workers had a shorter total sleep time （TST） （p 〈 0.001）, a longer stage 1 non-rapid eye movement （nREM） sleep （p 〈 0.05） and a shorter 3＋4 nREM and rapid eye movement （REM） sleep （p 〈 0.05） with a severe sleep hypoxemia （p 〈 0.01）. Our data suggested that sea-level workers revealed a disturbed sleep and a bad sleep quality with a significant sleep hypoxemia at altitude of 3 750 m. Strengthening the prevention and treatment are thereby sorely necessary.
