共查询到19条相似文献,搜索用时 234 毫秒
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为了进一步提高太阳能光热转换效率,设计了一种用于槽式太阳能集热装置双轴自动跟踪太阳的日跟踪器.该跟踪器以视日运动轨迹跟踪为主,当太阳辐照度较强时,由光电传感器进行误差校正,使聚光器始终正对太阳,避免阴天或多云天气对跟踪的影响.理论分析表明,该跟踪器可提高能量接收率,便于自动控制. 相似文献
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太阳能发电具有干净、不会威胁人类和破坏环境的优点,提高太阳能板发电效率成为当今研究的热点;以单片机为控制核心,读取GPS的经纬度和当地时间等信息,根据视日运动轨迹模型精确解算太阳方位角和高度角,发送相应脉冲驱动步进电机,经过减速器减速实现对太阳能板的姿态调整,从而实现对太阳光的精确跟踪;安装于太阳能板上的姿态传感器可以将姿态信息反馈给控制器从而实现闭环控制,进一步提高了系统的精度,安装的风速传感器使太阳能跟踪器具有抗风性能;实验表明,太阳跟踪器可有效跟踪太阳角,跟踪精度可达到2°左右,大大提高了太阳能板的发电效率,具有很好的应用前景。 相似文献
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为了提高太阳能利用率,设计了一种基于ARM7的太阳自动跟踪简易控制系统;该系统利用32位ARM嵌入式微处理器LPC2131为控制器,采用光电跟踪和定时跟踪相结合的控制方式;以步进电机作为驱动机构,通过控制跟踪的机构水平、俯仰两个方向运动,实现对太阳的全跟踪;仿真和试验结果表明,该控制系统的跟踪精度误差在1°以内,能够满足太阳自动跟踪的需要,且性能稳定、功能丰富、成本较低,可以为太阳能飞行器的太阳自动跟踪控制工程研制提供参考依据。 相似文献
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基于TMS320F2812的太阳跟踪器设计 总被引:1,自引:1,他引:0
采用传感器和太阳位置计算相结合的方法,设计了基于TI公司的TMS320F2812的高精度太阳跟踪器。一方面可以防止较大误差积累,另一方面可以避免光线、天气情况的影响,跟踪精度得到了较大提高,能够很好地应用于光伏发电系统实现对太阳的精确跟踪。 相似文献
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苏云成 《数字社区&智能家居》2014,(34):8322-8323
设计一种根据视日运动规律自动跟踪太阳的系统。采用太阳高度-方位角双轴跟踪的办法,利用步进电机双轴驱动,通过对跟踪系统进行水平、俯仰两个自由度的控制,实现对太阳的实时跟踪。该系统适用于各种太阳能采集装置。主要从硬件和软件方面分析太阳自动跟踪系统的设计与仿真实现。系统在实际跟踪过程中运行状况良好,跟踪速度快捷。 相似文献
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苏云成 《数字社区&智能家居》2014,(12):8322-8323
设计一种根据视日运动规律自动跟踪太阳的系统。采用太阳高度-方位角双轴跟踪的办法,利用步进电机双轴驱动,通过对跟踪系统进行水平、俯仰两个自由度的控制,实现对太阳的实时跟踪。该系统适用于各种太阳能采集装置。主要从硬件和软件方面分析太阳自动跟踪系统的设计与仿真实现。系统在实际跟踪过程中运行状况良好,跟踪速度快捷。 相似文献
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针对近景摄影测量中对编码标志点的精确定位和准确识别的要求,提出一种环状编码标记点的设计和识别算法。在传统环状编码标记点的基础上添加3个定位符,用于确定标志点的精确位置和增加标志点的数量。解码时先检测定位符坐标及其在标志点中的位置,然后对编码标志点进行透视变换以实现图像校正的目的,最后用提出的基于圆环扫描的方法进行解码。实验结果表明,该算法对任意旋转角度下的编码标志点均能有较好的检测识别效果;当摄像机与标记平面的夹角小于65°时,其识别准确率可达99.3%;在复杂背景情况下的平均识别准确率为97.4%,误识别率为1.25%,识别平均速率为2.15 s/幅。 相似文献
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K.T Kriebel 《Remote sensing of environment》1979,8(4):283-290
The albedo of four vegetated surfaces was investigated to derive its variability with differing distributions of the irradiance. The results are based on measured values of the spectral biconical reflectance factor, which are combined with calculated spectral irradiances for low and high atmospheric turbidity. The solar zenith angle is varied from 0° to 80°. The derived spectral albedos are then integrated with respect to wavelength in order to achieve the albedo. It is found that the variability of the albedo with respect to the atmospheric turbidity is less than 0.01 in nearly all cases. The variability of the albedo with respect to the solar elevation angle, however, is larger than 0.02 in many cases. For solar elevation angles from 20° to 60°, the variability of the albedo of the four surfaces can be represented by a mean curve which fits the individual variabilities with an accuracy of 0.015. 相似文献
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Wen-Ruey Chang Yueng-Hsiang Huang Chien-Chi Chang Christopher Brunette Nils Fallentin 《Ergonomics》2016,59(8):1100-1108
Ladder inclined angle is a critical factor that could lead to a slip at the base of portable straight ladders, a major cause of falls from heights. Despite several methods established to help workers achieve the recommended 75.5° angle for ladder set-up, it remains unclear if these methods are used in practice. This study explored ladder set-up behaviours in a field environment. Professional installers of a company in the cable and other pay TV industry were observed for ladder set-up at their worksites. The results showed that the actual angles of 265 ladder set-ups by 67 participants averaged 67.3° with a standard deviation of 3.22°. Although all the participants had training on recommended ladder set-up methods, only 3 out of 67 participants applied these methods in their daily work and even they failed to achieve the desired 75.5° angle. Therefore, ladder set-up remains problematic in real-world situations.
Practitioner Summary: Professional installers of a cable company were observed for portable straight ladder set-up at their worksites. The ladder inclined angle averaged 67.3° with a standard deviation of 3.22°, while the recommended angle is 75.5°. Only a few participants used the methods that they learned during training in their daily work. 相似文献
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针对重型履带系统复杂的车辆 地面力学问题,使用Adams ATV模块建立电铲整机模型,准确计算在软地面爬坡、转弯和越障等工况下履带系统的驱动力矩和支重轮受力。爬坡工况下履带系统驱动力矩仿真结果与理论值基本一致,转弯工况下驱动力矩理论值与仿真结果的相对误差在2.5%~26.2%区间;原地转弯所需驱动力矩与12.5°坡角爬坡所需驱动力矩接近。在硬地面越障时,支重轮受力最大值占整机总重力的41.8%。与实际使用值对比结果表明,仿真结果和理论计算值可作为方案设计的参考,且理论计算值偏于保守;各工况计算结果可为动力配置和后继强度设计提供依据。 相似文献
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飞行安全是民航发展的基础,经统计,有40%~50%的飞行事故发生在起飞降落的“黑色十分钟”;为保证恶劣气象条件下飞机的安全率,文章使用Retinex方法和形态学的权重自适应算法对机场恶劣天气下的监视视频进行去雾降噪处理,之后采用光流法与混合高斯-卡尔曼滤波等机器视觉算法实现同时对多目标的检测、跟踪和预测;最后建立摄像机标定算法完成摄像机视角与机场视角坐标的转换,构建一套完整的机场跑道侵入的预警系统。 相似文献
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形状记忆合金(Shape Memory Alloys,SMA)由于其特有的形状记忆效应(Shape Memory Effect,SME)被大量研究和广泛应用。基于SMA的Müller-Achenbach-Seelecke模型进行了单根SMA丝的回复力数值计算验证,并设计了一种SMA丝驱动器应用于机翼变后掠角结构中,完成了机翼连续后掠偏转的原理、方案和具体的结构设计,并加工制备了后掠机翼模型;同时为了实现机翼后掠角变化的精确控制,采用PID控制方法设计了SMA温度与偏转角度双路信号反馈的闭环控制系统,完成了对机翼偏转的控制。实验结果表明,机翼可实现45°的偏转,偏转至设定角度后的平均稳态误差控制在±0.3°以内,实现了对偏转角度的精确控制。 相似文献
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Min Seok Kim Hongbae Son Jungwon Kang 《Journal of the Society for Information Display》2010,18(11):982-987
Abstract— The goal of this work is to achieve a better understanding of the electro‐optical characteristics of a VA‐mode full‐HD LCOS panel via simulations and experiments. The optical parameters, such as reflectance, fill factor, and contrast that vary due to the pre‐tilt angle and cell gap, were also studied. Based on the simulations, the optical fill factor was the highest at an angle of 81° and 2.1 μm under the given conditions. The contrast ratio was the highest at an angle of 89° and 2.4 μm. Five different LCOS panels were fabricated; three different angles (85°, 87°, and 89°) at a 2.1‐μm cell gap and two different cell gaps (1.8 and 2.1 μm) at an angle of 87°. The measured reflected light intensity was compared to the calculated reflectance. The simulated and measured contrasts were compared with each other. The simulation results well‐matched the experimental results and the differences were less than a few percentage points. Based on the comparative studies on reflectance and contrast, the test panel under the condition of an 87° angle and 2.1‐μm gap showed the best performance results. 相似文献