Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed ter...Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed terminal state and time. Applying the proposed optimal control to the simple two-input dual-stage actuator magnetic head positioning system with three degrees-of-freedom, the simulation results show that the system has no residual vibration at the terminal position and time, which can reduce the total access time during head positioning process. To verify the validation of the optimal control strategy of three degrees-of-freedom spring-mass models in actual magnetic head positioning of hard disk drives, a finite element model of an actual magnetic head positioning system is presented. Substituting the optimal control force from simple three degrees-of-freedom spring-mass models into the finite element model, the simulation results show that the magnetic head also has no residual vibration at the end of track-to-track travel. That is to say, the linear quadratic optimal control technique based on simple two-input dual- stage actuator system with three degrees-of-freedom proposed in this paper is of high reliability for the industrial application of an actual magnetic head positioning system.展开更多
驾驶人行为习惯很大程度上影响了车辆的油耗及尾气排放.厘清不良驾驶行为(如怠速和急加减速等)与车辆碳排放的关系,对城市碳减排具有重要意义.基于广泛高精度的轨迹数据,结合车辆比功率(vehicle specific power,VSP)法计算不同尺度的碳...驾驶人行为习惯很大程度上影响了车辆的油耗及尾气排放.厘清不良驾驶行为(如怠速和急加减速等)与车辆碳排放的关系,对城市碳减排具有重要意义.基于广泛高精度的轨迹数据,结合车辆比功率(vehicle specific power,VSP)法计算不同尺度的碳排放特征,构建驾驶行为特征集;分析车辆碳排放分布,利用t-分布随机邻域嵌入(t-distributed stochastic neighbor embedding,t-SNE)算法进行特征约简,并基于k-medoids算法进行聚类分析,捕捉高碳排放驾驶行为的共性;利用最大信息系数(maximal information coefficient,MIC)算法分析不同优先级车辆驾驶行为对碳排放的影响.结果表明,聚类分析将车辆划分为怠速型、普通型及急变速型3类,对应占比分别为28.8%、44.9%及26.3%,碳排放与道路优先级存在明显相关性,主次路车辆碳排放分布差异显著.高优先级车辆碳排放与车辆加速类特征相关性强,对于低优先级车辆,航向角变化值、怠速比例、最小车速与车辆碳排放相关性强.通过识别碳排放高的驾驶行为,提出针对性减少车辆动态运行状态下碳排放的措施,有利于完善城市碳减排体系建设.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 10472038）；the Science Foundation of the Ministry of Education of China for Ph.D. Programme （No. 20050730016）；the National Science Foundation of China for 0utstanding Young Researchers （No. 10025208）.
文摘Based on generalized the variation method, by introducing Hamilton function and Lagrange multiplier, this paper proposed a linear quadratic optimal control strategy for an incomplete controllable system with fixed terminal state and time. Applying the proposed optimal control to the simple two-input dual-stage actuator magnetic head positioning system with three degrees-of-freedom, the simulation results show that the system has no residual vibration at the terminal position and time, which can reduce the total access time during head positioning process. To verify the validation of the optimal control strategy of three degrees-of-freedom spring-mass models in actual magnetic head positioning of hard disk drives, a finite element model of an actual magnetic head positioning system is presented. Substituting the optimal control force from simple three degrees-of-freedom spring-mass models into the finite element model, the simulation results show that the magnetic head also has no residual vibration at the end of track-to-track travel. That is to say, the linear quadratic optimal control technique based on simple two-input dual- stage actuator system with three degrees-of-freedom proposed in this paper is of high reliability for the industrial application of an actual magnetic head positioning system.
文摘驾驶人行为习惯很大程度上影响了车辆的油耗及尾气排放.厘清不良驾驶行为(如怠速和急加减速等)与车辆碳排放的关系,对城市碳减排具有重要意义.基于广泛高精度的轨迹数据,结合车辆比功率(vehicle specific power,VSP)法计算不同尺度的碳排放特征,构建驾驶行为特征集;分析车辆碳排放分布,利用t-分布随机邻域嵌入(t-distributed stochastic neighbor embedding,t-SNE)算法进行特征约简,并基于k-medoids算法进行聚类分析,捕捉高碳排放驾驶行为的共性;利用最大信息系数(maximal information coefficient,MIC)算法分析不同优先级车辆驾驶行为对碳排放的影响.结果表明,聚类分析将车辆划分为怠速型、普通型及急变速型3类,对应占比分别为28.8%、44.9%及26.3%,碳排放与道路优先级存在明显相关性,主次路车辆碳排放分布差异显著.高优先级车辆碳排放与车辆加速类特征相关性强,对于低优先级车辆,航向角变化值、怠速比例、最小车速与车辆碳排放相关性强.通过识别碳排放高的驾驶行为,提出针对性减少车辆动态运行状态下碳排放的措施,有利于完善城市碳减排体系建设.
