针对现有磁悬浮控制系统设计方法依赖动力学模型的问题,利用Q网络强化学习方法,在不依赖系统模型的条件下,训练得到基于Q网络的自学习控制器;基于系统运动方向设计奖励函数,提高了强化学习训练的收敛速度;提出了基于系统加权平均状态(we...针对现有磁悬浮控制系统设计方法依赖动力学模型的问题,利用Q网络强化学习方法,在不依赖系统模型的条件下,训练得到基于Q网络的自学习控制器;基于系统运动方向设计奖励函数,提高了强化学习训练的收敛速度;提出了基于系统加权平均状态(weighted average states,WAS)的训练算法,自适应调节每回合的训练步数,以提高控制网络的有效控制范围。数值仿真结果表明,基于WAS算法的Q网络自学习控制器能够实现磁悬浮系统的稳定控制,对比普通的强化学习算法,能够实现系统更大范围的稳定控制。展开更多
Four types of magnetic alloy cores,labeled as V1,V2,A1 and A2,were produced by Liyuan Corp.Ltd.,for the radio frequency compression cavity of HIRFL-CSRm.In this work,their permeability,quality factor (Q value) and shu...Four types of magnetic alloy cores,labeled as V1,V2,A1 and A2,were produced by Liyuan Corp.Ltd.,for the radio frequency compression cavity of HIRFL-CSRm.In this work,their permeability,quality factor (Q value) and shunt impedance were measured before installing them into the cavity.The results show that the V1,V2 and A2 have higher permeability and shunt impedance,and lower Q value,and are suitable to the radio frequency compression cavity.展开更多
Rock magnetism is useful in various applications. Hematite is one of the two most important carriers of magnetism in the natural world and its magnetic features were mostly studied through laboratory experiments using...Rock magnetism is useful in various applications. Hematite is one of the two most important carriers of magnetism in the natural world and its magnetic features were mostly studied through laboratory experiments using synthetic hematite samples. A gap exists between the magnetic behaviors of hematite contained in the natural rocks and ores and those of synthetic hematite samples. This paper presents the results of a rock magnetism study on the natural hematite ores from the Whaleback mine in the Hamersley Province in the northwest of Western Australia. It was found that high-grade hematite ores carry a much higher remanent magnetization than induced magnetization. Hematite ores with less than 0.1% magnetite appear to have an exponential correlation between the bulk susceptibility and hematite content in weight percentage, different from the commonly accepted linear relationship between the bulk susceptibility and hematite content obtained from synthetic hematite samples. The new knowledge gained from this study contributes to a better understanding of magnetic behaviors of hematite, particularly natural hematite, and hence applications to other relevant disciplines.展开更多
文摘针对现有磁悬浮控制系统设计方法依赖动力学模型的问题,利用Q网络强化学习方法,在不依赖系统模型的条件下,训练得到基于Q网络的自学习控制器;基于系统运动方向设计奖励函数,提高了强化学习训练的收敛速度;提出了基于系统加权平均状态(weighted average states,WAS)的训练算法,自适应调节每回合的训练步数,以提高控制网络的有效控制范围。数值仿真结果表明,基于WAS算法的Q网络自学习控制器能够实现磁悬浮系统的稳定控制,对比普通的强化学习算法,能够实现系统更大范围的稳定控制。
基金Supported by Innovation Research Community of National Natural Science Foundation of China(10921504)
文摘Four types of magnetic alloy cores,labeled as V1,V2,A1 and A2,were produced by Liyuan Corp.Ltd.,for the radio frequency compression cavity of HIRFL-CSRm.In this work,their permeability,quality factor (Q value) and shunt impedance were measured before installing them into the cavity.The results show that the V1,V2 and A2 have higher permeability and shunt impedance,and lower Q value,and are suitable to the radio frequency compression cavity.
文摘Rock magnetism is useful in various applications. Hematite is one of the two most important carriers of magnetism in the natural world and its magnetic features were mostly studied through laboratory experiments using synthetic hematite samples. A gap exists between the magnetic behaviors of hematite contained in the natural rocks and ores and those of synthetic hematite samples. This paper presents the results of a rock magnetism study on the natural hematite ores from the Whaleback mine in the Hamersley Province in the northwest of Western Australia. It was found that high-grade hematite ores carry a much higher remanent magnetization than induced magnetization. Hematite ores with less than 0.1% magnetite appear to have an exponential correlation between the bulk susceptibility and hematite content in weight percentage, different from the commonly accepted linear relationship between the bulk susceptibility and hematite content obtained from synthetic hematite samples. The new knowledge gained from this study contributes to a better understanding of magnetic behaviors of hematite, particularly natural hematite, and hence applications to other relevant disciplines.
