基于城市小区域的车联网模型

随着社会进步及车辆增多,交通问题日益突出,使得城市环境下车联网的研究受到越来越多的关注。基于真实数据的分析和验证,可以得到城市不同区域的车联网网络度分布服从广义的幂律分布,即网络是无标度网络。根据此性质利用复杂网络理论建立车联网网络模型,通过分析和仿真验证该模型的正确性和有效性。     

Dynamic output feedback control of a flexible air-breathing hypersonic vehicle via T–S fuzzy approach

By utilising Takagi–Sugeno (T–S) fuzzy set approach, this paper addresses the robust H_∞ dynamic output feedback control for the non-linear longitudinal model of flexible air-breathing hypersonic vehicles (FAHVs). The flight control of FAHVs is highly challenging due to the unique dynamic characteristics, and the intricate couplings between the engine and fight dynamics and external disturbance. Because of the dynamics’ enormous complexity, currently, only the longitudinal dynamics models of FAHVs have been used for controller design. In this work, T–S fuzzy modelling technique is utilised to approach the non-linear dynamics of FAHVs, then a fuzzy model is developed for the output tracking problem of FAHVs. The fuzzy model contains parameter uncertainties and disturbance, which can approach the non-linear dynamics of FAHVs more exactly. The flexible models of FAHVs are difficult to measure because of the complex dynamics and the strong couplings, thus a full-order dynamic output feedback controller is designed for the fuzzy model. A robust H_∞ controller is designed for the obtained closed-loop system. By utilising the Lyapunov functional approach, sufficient solvability conditions for such controllers are established in terms of linear matrix inequalities. Finally, the effectiveness of the proposed T–S fuzzy dynamic output feedback control method is demonstrated by numerical simulations.     

攻击型无人机鲁棒导引律研究

文章研究了攻击型无人机鲁棒导引系统,采用对干扰和摄动具有自适应能力的滑动模态变结构控制方法设计了攻击型无人机滑模导引规律.针对用于消除颤振的伪滑动模态不能实现精确跟踪的缺陷,对滑模导引规律中颤振消除进行了优化设计,引入系统运动状态轨迹接近角变量,使消除颤振的伪滑动模态边界层宽度随着系统状态到达滑动模态而逐渐减小为零,从而达到了既能消除颤振又能实现精确跟踪的设计目标.通过仿真验证了该导引规律具有攻击弹道平缓、抗目标机动扰动能力强、鲁棒性好、制导精度高的优点.     

运输部机车车辆检修库平面布置分析

随着我国国民经济的持续快速发展,各钢铁企业加快了钢铁工业战略性结构调整的力度.因此,本篇论文对运输部机车车辆检修库平面布置进行分析,为运输部机车车辆检修库的设计提供借鉴.     

Guaranteed transient performance based control with input saturation for near space vehicles

This paper describes the design of guaranteed transient performance based attitude control for the near space vehicle(NSV)with control input saturation using the backstepping method.To improve the robust controllability of the NSV,the parameter adaptive method is used to tackle the integrated effect of unknown time-varying disturbance and control input saturation.Based on the backstepping technique and parameter estimated outputs,a robust attitude control scheme is proposed for the NSV with input saturation.A novel robust attitude control scheme is then proposed based on a prescribed performance bound(PPB)which characterizes the convergence rate and maximum overshoot of the attitude tracking error.The closed-loop system stability under both the developed robust attitude control schemes is proved using Lyapunov’s method and uniformly asymptotical convergence of all closed-loop signals is guaranteed.Finally,simulation results are given to show the effectiveness of both the proposed robust constrained attitude control schemes.     

Long-term economic sensitivity analysis of light duty underground mining vehicles by power source

LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.     

考虑环境温度的电动汽车充电负荷预测

为了保证电动汽车充电负荷预测更加准确、合理,分析环境温度导致电池特性、空调能耗和道路状况的变化对电动汽车充电需求的影响。考虑环境温度因素,引入能耗因子计算单位里程耗电量,利用蒙特卡洛法计算单辆车的充电负荷需求,再累加到总的充电负荷曲线上。以2020年上海市电动汽车为例仿真计算,验证了在不同温度影响下,电动汽车充电负荷会发生明显的变化。     

电动汽车用锂离子电池热特性试验研究

为研究锂离子电池的热特性,以3 200 m A·h、3.67 V圆柱形三元材料锂电池为研究对象,进行了不同温度、不同充/放电倍率的热特性试验和低温加热试验.试验结果表明:随着充/放电电流的增大以及环境温度的降低,电池温度快速升高,低温下加热可以提高锂离子电池的充/放电性能.     

JCOE钢管生产线精整横移台车运行故障分析及改进

针对JCOE钢管生产线精整横移台车在使用过程中出现的钢管放置不到位、托起钢管时在台架、辊道处撞击钢管等问题,分析了其产生原因,发现横移台车编码器的累积误差以及通讯闪断引起的编码器位置数据清零是产生故障的主要原因。通过增加位置校正接近开关和程序改进,能够减少横移台车的累积误差,解决横移台车编码器位置数据丢失的问题,消除了横移台车自动运行时撞击台架、撞管以及钢管放偏故障,从而保障钢管在生产过程中的安全平稳传送。     

考虑交通流量捕获的风-氢-电耦合网络规划

研究在风-氢-电耦合网络下的制氢加氢站(HPRS)与风电场的选址定容问题,以期实现HPRS与风电场的科学布局.首先,建立了包含氢气生产、压缩和储存并被注入氢燃料汽车的HPRS全流程模型,模拟现场电解水HPRS的氢气生产和消耗;其次,提出交通网的加氢逻辑规则及网络扩展技术;最后,同时考虑交通网络约束、电力网络约束和设备运行约束,构建考虑交通流量捕获的风-氢-电耦合网络规划模型.以IEEE 33节点电力网络和25节点交通网络作为算例测试系统,研究结果验证了所提模型的有效性.