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高速列车自动驾驶非线性广义预测控制方法及应用研究
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作者 徐建亮 望文铎 +2 位作者 彭汉舟 徐文俊 徐峰 《建模与仿真》 2024年第5期5287-5299,共13页
针对高速列车运行过程中具有的强非线性、运行参数时变等问题设计列车自动驾驶的非线性广义预测控制方法。首先采用双线性变换将列车动力学模型离散化为线线模型,将非线性空气阻力描述为未建模动态项,线性模型和未建模动态项组合成集成... 针对高速列车运行过程中具有的强非线性、运行参数时变等问题设计列车自动驾驶的非线性广义预测控制方法。首先采用双线性变换将列车动力学模型离散化为线线模型,将非线性空气阻力描述为未建模动态项,线性模型和未建模动态项组合成集成模型;根据高速列车线路实际运行数据,采用递推辨识算法更新模型中因列车运行环境变化而时变的运行参数,利用极限学习机神经网络估计未建模动态项,建立列车运行过程模型。基于高速列车集成模型,设计以运行速度跟踪为主要控制目标的列车非线性广义预测控制方法。非线性广义预测控制器中,反馈控制器用来控制输出跟踪参考输入,补偿器用来消除未建模动态项对闭环系统的影响,保证列车的速度跟踪精度。仿真结果表明集成模型输出与实际输出的均方根误差为0.1653 km/h,小于线性模型的均方根误差1.454 km/h;并通过与多模型广义预测控制方法的比较显示本文的控制方法跟踪误差更小;所提出算法较BP神经网络方法更加快速。 展开更多
关键词 高速列车 动力学模型 未建模动态 极限学习机 参数辨识 非线性广义预测控制
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Functional nanogenerators as vibration sensors enhanced by piezotronic effects 被引量:6
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作者 Zheng Zhangt Qingliang Liao +6 位作者 Xiaoqin Yan Zhong Lin wang wenduo wang Xu Sun Pei Lin Yunhua Huang Yue Zhang 《Nano Research》 SCIE EI CAS CSCD 2014年第2期190-198,共9页
ZnO nanomaterials have been shown to have novel applications in optoelectronics, energy harvesting and piezotronics, due to their coupled semiconducting and piezoelectric properties. Here a functional nanogenerator (... ZnO nanomaterials have been shown to have novel applications in optoelectronics, energy harvesting and piezotronics, due to their coupled semiconducting and piezoelectric properties. Here a functional nanogenerator (FNG) based on ZnO nanowire arrays has been fabricated, which can be employed to detect vibration in both self-powered (SP) and external-powered (EP) modes. In SP mode, the vibration responses of the FNG can be measured through converting mechanical energy directly into an electrical signal. The FNG shows consistent alternating current responses (relative error 〈 0.37%) at regular frequencies from 1 to 15 Hz. In EP mode, the current responses of FNG are significantly enhanced via the piezotronic effect. Under a forward bias of 3 V, the sensor presented a sensitivity of 3700% and an accurate measurement (relative error 〈 0.91%) of vibration frequencies in the range 0.05-15 Hz. The results show that this type of functional nanogenerator sensor can detect vibration in both SP and EP modes according to the demands of the applications. 展开更多
关键词 functional nanogenerator ZnO nanowires arrays piezotronic effects piezoelectric effects vibration sensor
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