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激光靶测速是速度测量的一种重要的实验方法,其测试效率高、精度高、抗干扰能力强、测速范围大、受环境因素影响小,很有工程应用前景。针对激光靶速度的实际工程应用背景,深入、系统地研究了在匀加速阶段和匀速阶段测速时影响测速相对误差的因素,得出了在这两个典型阶段测速时,激光靶的安装位置及其精度与测速相对误差的重要关系。同时,分析得到了在给定测速相对误差前提下,激光靶的最佳安装间距。上述结果对激光靶测速的相关工程应用和相关实验的设计与开发具有重要的指导意义。 相似文献
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无人船在水质检测、采样、巡逻等方面有着广阔的应用前景。针对无人船传输数据实时性差的问题，利用4G网络结合数据传输模块进行无人船与控制中心之间的数据传输；针对具有自主能力的无人船造价昂贵的问题，以树莓派为控制中心设计无人船控制系统，实现无人船的自动巡航；针对无人船无法自动处理突发情况的问题，采用移动端、遥控器、服务器端多端控制的方法；针对无人船适应环境能力较差的问题，采用PID算法进行无人船的航向控制。实验结果表明，该算法可实现无人船的多端控制、数据实时传输与自动巡航功能。 相似文献
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In this paper, a plug-in hybrid electrical vehicle (PHEV) is taken as the research object, and its dynamic performance and economic performance are taken as the research goals. Battery charge-sustaining (CS) period is divided into power mode and economy mode. Energy management strategy designing methods of power mode and economy mode are proposed. Maximum velocity, acceleration performance and fuel consumption are simulated during the CS period in the AVL CRUISE simulation environment. The simulation results indicate that the maximum velocity and acceleration time of the power mode are better than those in the economy mode. Fuel consumption of the economy mode is better than that in the power mode. Fuel consumption of PHEV during the CS period is further improved by using the methods proposed in this paper, and this is meaningful for research and development of PHEV. 相似文献
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The settling of sediments is an accelerative process in which the concentration of the main sediments zone will heavily influence settling velocity，but the explicit relationship between the concentration and settling velocity has not been reported in literature. Here a theoretical function was built for the time dependent concentration and time dependent settling velocity of sediments；then the entire settling process reflecting concentration was shown on the basis of sediments instant-settlement theory and mathematical method. Agreement of computed results and experimental data was found. Several governing parameters，including particle size，particle density，initial suspended sediments concentration and suspension height，were discussed with a series of calculated velocity curves. The research indicated that ⑴ the presented concentration-velocity time relationship is rational，⑵ settling process of the sediments group with variation of concentration consists of acceleration stage，uniform motion stage and deceleration stage，and ⑶ particle size，particle density and initial suspended sediments concentration have more influence on the settling velocity than the suspension height and water temperature. 相似文献
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通过水力学模型试验,研究了春堂坝水电站引水枢纽的两个布置方案对过流能力、建筑物下游流速、河床冲刷及右岸边坡的影响。结果显示建筑物下游存在局部掏刷问题,右岸边坡坡脚也有一定冲刷,建议在进行建筑物设计时予以重视。 相似文献
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对有限频段内汽车悬架系统的时滞反馈控制参数优化问题进行研究。首先,建立时滞加速度反馈控制下 1/4 汽车悬架系统力学模型,推导出车身和车轮加速度幅值的解析表达式;其次,通过对系统稳定性分析,得到关于反馈增益系数和时滞的稳定性分区图,以数值计算验证稳定性分析的正确性;最后,在有限频段内以最大车身加速度变化的百分比为优化目标,以反馈增益系数和时滞为优化参数,利用粒子群优化算法获得有限频段内最优反馈增益系数和时滞。实验结果表明,与被动汽车悬架系统相比较,最优时滞反馈控制下汽车悬架系统的隔振性能获得了明显提高,在最优时滞反馈控制参数取值下,有限频段内车身加速度幅值至少降低37.27%。 相似文献
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董斌 《福建工程学院学报》2008,6(1):100-102
针对老城区内河岸上敷设污水截流干管存在困难的特点.提出河床下敷设截流干管的设计方案及相应的技术措施.通过经济效益、社会效益、环境效益比较,认为该截流方案及技术措施对老城区内河污水的截流、城市水环境的改善具有一定的可操作性. 相似文献
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根据车辆横向运动动力学模型,采用全反馈控制策略,并考虑到人的差异,提出了影响控制策略的组合系数,可以通过人为地选择组合系数,来调整转向传动比和转向增益.仿真结果表明,可使质心侧偏角降低到零而侧向加速度增益和横摆角速度增益保持不变,并能减少系统波动幅值和进入稳态所经历的时间,从而保证车辆的反应快速灵活.在保持上述特性不变的情况下,可人性化地选择转向传动比和转向增益,进一步提高了车辆的操纵稳定性、行驶安全性和司机的驾驶舒适性. 相似文献
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A K Shukla 《Resonance》2001,6(11):49-62
Road transportation as an important requirement of modern society is presently faced with restrictions in mainly two respects,
namely the ever tightening emission legislation as well as the availability of petroleum fuels, and as a consequence the fuel
cost. But in any review of power sources for future road transport vehicles, the performance of the existing internal combustion
engine is likely to be the yardstick against which other power sources will be compared. The power sources most likely to
provide favourable comparison are those, which can display comparable range and speed, long and reliable life and manufactured
at a cost comparable to petrol engine. A vehicle which fails in any of these requirements is unlikely to achieve anything
but a niche market share. This article is an appraisal of a variety of proposed electrochemical systems, viz. rechargeable
batteries, fuel cells and supercapacitors, for an electric car. It is surmised that a viable electric car could be powered
with a fuel cell to provide power for cruising and climbing coupled in parallel with a supercapacitor/battery bank to deliver
additional short-term burst-power during acceleration.
A K Shukla is a Professor at the Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore. His current
research interests are in materials electrochemistry with special emphasis on batteries, fuel cells and supercapacitors. 相似文献
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移动监控定位系统在车辆调度、航海导向、公安巡防、银行运钞车监控等领域应用十分广泛.介绍了移动监控定位系统的应用,解释了基于GPS/GSM的移动监控定位系统的结构,并给出了移动监控定位系统中移动单元的硬件电路和软件设计构思. 相似文献
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李霁 《北京教育学院学报》2007,21(1):6-8,28
从《哀郢》一文的地名考究中,可以看到屈原的一段流放的行程:出郢都、江夏,便过夏首;由夏首沿江向西南漂,又折向东下到洞庭;经过洞庭沿江东去到夏浦;过夏浦东流,最后到达陵阳。 相似文献
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从刚体平面运动的速度瞬心轨迹出发,推导得到在刚体由静止开始运动的初瞬时加速度瞬心与速度瞬心重合,可用于解答运动初瞬时刚体平面运动的动力学问题。 相似文献
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蔡盛炽 《重庆第二师范学院学报》2010,23(1):53-56
乌江盐运历史起源甚早,有关航道、社会条件以及船型、运量、供应地区等重要内容,史籍所载资料丰富,包括乌江盐运对沿江城镇兴起的特殊带动作用,历代盐运船工的生活方式等,都是值得深入研究的课题。 相似文献