機電外文文獻翻譯--采用Atmel 89S51微控制器的風速風向測量系統【中文4420字】【PDF+中文WORD】

機電外文文獻翻譯--采用Atmel 89S51微控制器的風速風向測量系統【中文4420字】【PDF+中文WORD】,中文4420字,PDF+中文WORD,機電外文文獻翻譯,采用Atmel,89S51微控制器的風速風向測量系統【中文4420字】【PDF+中文WORD】,機電,外文,文獻,翻譯,采用,Atmel,89 【中文4420字】 采用Atmel 89S51微控制器的風速風向測量系統 Eunice Sophia K T 物理系 Sri Krishnadevaraya大學，Anantapuramu -515003，A.P.，印度 電子郵件：eunice.sophia@gmail.com Raghavendra Rao Kanchi SK大學工程與技術學院物理系主任，VLSI與嵌入式系統實驗室教授， Anantapuramu - 515003，A.P.印度 電子郵件：kanchiraghavendrarao@gmail.com 摘要 - 本文介紹了圍繞8051系列微控制器之一構建的簡單儀器設計，用于測量瞬時風速和風向。 這個系統包括一個改進，但價廉的杯式風速計：戴維斯儀器6410感測上述兩個風的參數。 處理系統的準確性在系統與風傳感器接口之前被估計。 該軟件采用C語言開發，數據每三秒鐘在16x2液晶顯示屏上顯示。 然后將收集的數據繪制成圓形直方圖進行分析。 所設計的系統由于其有效測量的原因而具有進一步發展和應用的潛力，這與標準讀數相關。 關鍵詞-AT89S51;風速計;LCD; 指南針點; 摩擦系數; 1、簡介 即使技術日新月異，器件變得更加智能化，8051微控制器及其衍生產品仍然有望在各種應用領域找到應用。 目前的工作是關于測量兩個主要的氣象變量[1]，即在氣象學，風資源評估研究，空中和水上航行，采礦和農業等許多應用中重要的風速和風向。 根據2011年3月的統計數據，印度僅安裝了29％的風力發電總潛力，其中32％單獨用于技術上[2]。 由于政府的目標是到2022年將風力發電量提高到60GW，顯然印度更加專注于利用可再生能源發電用于清潔能源技術。 因此，該研究提出了可能提供潛在風資源評估的設計。 風一般是通過其標量組件進行測量和分析的; 與風向標或風向標的風速計和風向的風速。 對流層空氣循環系統的年度性質，同時影響著一個地點的風速和風向[3]。 由于其線性和準確性，通常使用杯型和螺旋槳型旋轉式風速計進行風速測量。 雖然所采取的測量通常是平均風資料，但瞬時風測量也很重要。 瞬時風速和方向數據有助于分析渦輪機和塔架的建造，而平均風速數據預測風力發電[4]。 由于功率與風速的立方功率成正比，因此風速測量的微小差異會大大影響發電量[5]。 所以準確的風速測量有助于計算安裝風力渦輪機的良好可行性研究。 在用于將旋轉速率轉換為用于記錄風速的適當電信號的不同機制[1]中，其中四種常用于使用直流發電機，交流發電機，電接觸器和中斷光束的換能器。 2、文獻調查 以前與風速計和葉片接口進行風速和風向測量的工作考慮如下： Ivan Simeonov等[6]開發了一種短期天氣預報嵌入式系統，其中風速傳感器給出方波脈沖，每升高1公里就需要修正風速讀數。 Michael Cosgrove等人[7]設計了一個超低成本的測風儀，用于風力發電的可行性調查。 在這種情況下，雖然磁簧開關在杯子的每次旋轉時產生一個單一開關閉合的脈沖，但是開發了去抖動的算法。 Haci Can和Vedat M. Karsh [8]從事數據記錄器的開發工作，使用基于8051的微控制器來測量風速和風向，也看到了對信號調理電路的需求。 Yahya S.H. Khraisat [9]在開發低成本的自動化系統的工作中，不斷測量直流發電機類型的端口電壓的天氣參數，在與微控制器接口之前，需要進行信號調理。 Fouad Sh. Tahir等人[10]設計了一個基于個人電腦的數據采集系統來測量溫度，風速和方向參數。即使當風速傳感器為杯子的一次旋轉而產生一個開關閉合周期時，在用于計算風速輸出的電路中增加了DAC。 David Wekesa等[11]利用Atmel Atmega 32微控制器開發了一種自動化，低成本的風速和方向數據記錄系統，該系統采用基于光電子的系統，可提供更高的每轉脈沖數，即6至44 [12]。 Mehedi Al Emram等[13]也開發了基于光電子學的風速和風向測量系統。對于風速計的風杯的單次旋轉產生多于一個的脈沖需要信號調節電路。 從上述考慮的工作中，產生正弦波的換能器需要額外的信號調節電路或具有去跳動電路的方波。 但是這個系統不需要信號調節，即使沒有任何去跳動電路或去跳動算法或者使用DAC，傳感器也很容易連接。通過使用摩擦系數從較低的高度推斷風速的值來進行高度的修正。 3、硬件 A. 硬件描述 硬件主要由AT89S51單片機，風速傳感器或風速計和LCD組成。 AT89S51是一款高性能的低成本微控制器。 它是一個具有4K字節在系統可編程閃存的8位微控制器。片上閃存使程序存儲器可以在系統內或通過傳統的非易失性存儲器編程器重新編程。AT89S51的其他顯著特點是：128字節的RAM，32條I / O線和2個16位定時器/計數器[14]。 所使用的風速計[15]具有對稱地保持在豎直軸上的3個半球形杯。這種機械式風速計的設計在旋轉過程中施加均勻的扭矩。 它是一種電氣接觸式的無源傳感器，可以計算一段時間內的吹氣量。 當磁簧開關接觸到磁鐵的影響時，設備不通電但發出脈沖。 簧片開關的安裝使得每次旋轉杯子時都會產生一次閉合。 傳感器包括密封軸承，使用壽命長，能夠抵御颶風的強風，雖然對起動閾值低的微風敏感。 傳感器的規格說明范圍和精度在風洞試驗中得到驗證。 杯子的材料重量輕，多功能和生態高效，其運行范圍從小于1英里/小時到200英里/小時（英里）。杯子的旋轉速度與吹風成正比。 與風速計相連的風向標是靈活的，響應速度快，指向風向。 葉片裝有一個20k電位器。 在葉片的方向相應的電壓被識別并且方向被相應地顯示在LCD上。 雨刮器到終端的阻力與方位角完全一致。 方向與氣象風向一致。 指向北方的葉片從0度開始，在羅盤上順時針方向移動16點。 表一.羅盤指示 指南針指向 等級 N 348.75 – 11.25 NNE 11.25 – 33.75 NE 33.75 – 56.25 ENE 56.25 – 78.75 E 78.75 – 101.25 ESE 101.25 – 123.75 SE 123.75 – 146.25 SSE 146.25 – 168.75 S 168.75 – 191.25 SSW 191.25 – 213.75 SW 213.75 – 236.25 WSW 236.25 – 258.75 W 258.75 – 281.25 WNW 281.25 – 303.75 NW 303.75 – 326.25 NNW 326.25 – 348.75 B. 硬件設計 該設計采用傳感器單元，隨后是處理單元和顯示單元。 圖1.系統的設計 處理單元由一個ADC和AT89S51單片機以及5V電源電路組成。 顯示單元有一個LCD，每3秒更新一次風速和風向信息。 通過使用來自函數發生器的與風傳感器（即TTL兼容的方波）相似的輸出來估算所設計的硬件的風速計算精度。 結果顯示在下表中。 表二. 頻率輸入與顯示輸出的比較 給定的頻率 (Hz) 計算值為2.25秒 LCD讀取2.25 秒 3 6.75 7 5 11.25 11 10 22.5 23 20 45 45 30 67.5 67 40 90 89 65 146.25 145 78 175.5 174 85 191.25 190 98 220.5 219 100 225 224 106 238.5 237 上面比較的結果表明處理單元的輸出與給定的頻率很好地相關。 傳感器發出的速度脈沖直接與微控制器連接，無需信號調節。 電路中使用的上拉電阻可確保單片機檢測到的信號始終為高電平，除非傳感器將其拉低。 該機制包括在2.25秒的采樣周期內對脈沖進行計數，這與風速和風向測量的推薦采樣平均次數1-5秒相一致[1]。 傳感器輸出的風向通過8位單通道ADC 0804與控制器連接。 微控制器被編程為根據ADC的值發出適當的方向。 功能電路圖如下： 圖2.電路框圖 電路的照片如下所示。 圖3.電路板上。 風速計被固定在一個2英尺的桿上，放在一個3層的建筑物上，用于露天測量。 傳感器布置在空氣自由流動的地方，但由于基礎設施的限制，不能滿足特定的要求，如固定在7英尺以上。 然而，在東北方向的一個不可避免的混凝土阻礙。 下圖顯示了傳感器的所有側面。 圖4.放置在露天讀數的風速計。 4、軟件 該軟件是使用KeilμVision5集成開發環境（IDE）以C語言開發的[16]。通過USB供電的傳統8051存儲器編程器將軟件的十六進制文件加載到微控制器上。 該軟件的流程圖如下： 圖5.風速和方向測量算法 五、結果與討論 速度的風速測量以英尺/分鐘的方向記錄，液晶顯示器上羅盤方向的縮寫。 傳感器對瞬間天氣狀況的反應似乎是靈活和準確的。 風向指向風向，風向很好地適應了風向的任何微小變化。 杯式風速計根據風向移動。 觀察是在一天中的三個半小時內進行的。 每2分鐘記錄的讀數平均為半個小時，并與印度斯里蘭卡克里希納德瓦拉亞大學（SKU）建立的氣溶膠和大氣研究實驗室（AARL）實驗室的聲速測量讀數的標準值進行比較。 10米高的標準讀數和16米高的觀測值列表如下： 表三. 標準和風速和方向的觀測值 Hr 標準WS10m（m / s） 觀測WS16m（m / s） 標準WDir 10m 觀測WDir16m（指南針點） 16.5 1.5267 1.69875 68.5148 (ENE) ENE 17.0 1.8173 2.01168 76.0462 (ENE) ENE 17.5 1.8193 2.06756 92.9933 (E) E 下圖顯示了使用Oriana 4軟件繪制的風玫瑰圖： 圖6. 16:00至16:30，ENE的風向平均值 圖7. 16:30至17:00期間ENE的風向平均值 圖8. 17:00至17:30 E期間的風向平均值 結果的幾點是： ·在16小時到16小時30分鐘的半小時內，大部分時間的風很大，占總數的50％，而東北偏東。 ·在16：30-17：00的時間段內，沿東 - 東北方向觀測到更高的風速，從東方吹來高頻風，甚至接下來的半小時。 ·由于大部分時間偏東風，西北側的障礙物對觀測影響很小，風向讀數與標準讀數恰好一致。 ·在16米處觀測到的風速高于預期的10米處的風速。 ·死區誤差從0o到5o，從355o到360o。 但后期的錯誤被編程淘汰了。 將10米高的風速標準值外推到觀測值相關的高度16米。 為了外推，使用了Hellmann提出的冪律[17]。 方程是： v / v0 =（H / H0）α（1） 其中v是高度H處的速度，v0是高度H0處的速度（通常被稱為10米高度），α是摩爾系數或Hellmann指數或風切變系數[18]。 這個系數是一個地點特定地形的函數，這個參數可以隨著一天中的小時，一年的時間以及大氣條件如空氣密度而變化。 下面的表格[17]涉及各種景觀的摩擦系數α。 表四. 不同景觀的摩擦系數表 地面類型 摩擦系數（α） 湖泊，海洋和光滑的硬地 0.10 草原（地面） 0.15 高大的作物，樹籬和灌木 0.20 森林茂密的土地 0.25 有一些樹木和灌木的小鎮 0.30 高層建筑物的城市地區 0.40 通過重寫（1）計算摩擦系數α α=（ln（v）-ln（v0））/（ln（H）-ln（H0））（2） 根據2016年4月1日15時至15時15分的標準風資料，18米高的風速（v）為1.4704m / s，10米高的風速（v0）為1.39m / s。 從（2），這些值的摩擦系數是0.1。 但觀測是在同一天從16Hr到17Hr 30min，當溫度下降，摩擦系數增加的時候進行。 因此，接下來的兩個摩擦系數即0.15和0.20被考慮用于從10m到16m的高度推斷標準讀數。 結果列表如下。 表五.外推的標準值和觀測的風速圖 S.No 時間(Hrs) WS(m/s) α=0.15 WS(m/s) α=0.20 觀察 WS (m/s) 1 16.5 1.6382 1.6771 1.69875 2 17 1.9499 1.9964 2.01168 3 17.5 1.9521 1.9986 2.06756 α等于0.15和0.20的摩擦系數的外推標準風速讀數與觀測到的風速值強相關。 相關系數分別為0.99091和0.99089。 從圖4可以看出，大部分時間的東風沒有任何明顯的障礙物。此外，觀測到的風速值稍高一些，可以用來解釋丘陵，建筑物等發生的風速加速。風會遇到阻塞[17]。 然而，電力管理對風力資料的長期觀測使用相對較短。 6.結論 利用AT89S51微控制器和Davis風速儀6410開發的系統測量實時風速和風向顯示的結果相當準確，這得到了當天同一時間SKU大氣研究實驗室的標準值的證實。所獲得的強相關系數表明該系統是可靠的。 參考 [1]美國環境保護局（EPA）。 “監管建模應用氣象監測指南”，2000年2月。EPA-454 / R-99-005。 [2] http://www.infraline.com/reportdetails/112/Wind-Power-Outlook-in- 印度2015.htm [3] http://green-power.com.pl/en/home/wiatr-i-jego-pomiar-w-energetyce- wiatrowej / [4] http://www.homepower.com/articles/wind-power/design- installation / understanding-wind-speed [5] http://www.wwindea.org/technology/ch01/en/1_4.html [6] I. Simeonov，H. Kilifarev，R. Llarionov，“短期天氣預報嵌入式系統”，計算機系統和技術國際會議論文集（CompSysTech'06），2006年。 [7] M. Cosgrove，B. Rhodes，J. Scott，“風力發電可行性調查的超低成本測井風速儀”，研究門，2007年1月。 [8] H. Can，V. M. Karsh，“利用基于8051的微控制器進行多點風速和方向測量和數據記錄”，美國科學雜志，157：2482-2488,2007。 [9] Yahya S. H. Khraisat，“在約旦設計無線氣象站”，加拿大科學和教育中心，第一卷。 2012年1月5日，1日。 [10] F. S. Tahir，A. M. Salman，J. K. Mohammed，W. K. Ahmed，“風速，方向和溫度測量的數據采集系統”，Journal of Engineering， 18，沒有。 11，第1229-1236頁，2012年11月。 [11] D.W Wekesa，J.N. Kamau，J.N. Mutuku，“用于風速和方向測量的校準數據記錄儀表系統”，工程創新基礎研究期刊， 1（3），第53-57頁，2013年6月。 [12] S. Pindado，J. Cubas，F. Sorribes-Palmer，“風杯測風儀，風能產業的基本氣象儀器。在IDR / UPM研究所進行研究“，Sensors， 2014年8月14日，第21428-21452頁。 [13] http://documents.mx/documents/a-microcontroller-based-system-for- determining-instantaneous-wind-speed-and.html [14] AT89S51 Datasheet.pdf。 [15]戴維斯風速儀6410 Datasheet.pdf。 [16] http://www.keil.com/c51/pk51kit.asp F.Banuelos-Ruedas，C.A. Camacho，S. Rios-Marcuello。 “在一個地區的風能資源評估中使用的方法”?？捎茫簑ww.intechopen.com [18] Firas A. Hadi，“診斷風速外推的最佳方法”，國際電氣，電子和儀器工程高級研究雜志。第一卷.2015年10月 Wind Speed and Direction Measurement System Using Atmel 89S51 Microcontroller Eunice Sophia K T Department of Physics,Sri Krishnadevaraya University,Anantapuramu-515003,A.P.,India.Email: Raghavendra Rao Kanchi Professor,VLSI&Embedded System Laboratory,Department of Physics and Principal,College of Engineering and Technology,SK University,Anantapuramu 515003,A.P.,India.Email: AbstractThis paper presents a simple instrumentation design built around one of the 8051 family microcontroller to measure instantaneous wind speed and wind direction.This system includes an improved,yet an inexpensive cup anemometer:Davis Instruments 6410 to sense the above said two wind parameters.The accuracy of the processing system is estimated prior to the interfacing the system with the wind sensor.The software is developed in C language and the data is displayed on 16x2 LCD for every three seconds.The collected data is then plotted in circular histogram for analysis.The system designed has the potential to be further developed and be used for in applications for the reason of its effective measurement which correlated well with the standard readings.KeywordsAT89S51;Anemometer;LCD;Compass points;Friction coefficient;I.INTRODUCTION Even as the technology improves day by day and the devices get smarter,8051 microcontroller and its derivatives still hold the promise of being a sufficient one in finding applications in various application fields.The present work concerns the measurement of two of the primary meteorological variables 1 namely wind speed and direction which is important in many applications like meteorology,wind resource assessment studies,air and water navigation,mining and agriculture.As per the statistics on March 2011,only 29%of the total gross potential for wind power development was installed in India of which 32%alone is technically usable 2.Since the government targets for to enhance the wind power production to 60GW by 2022,its clear that India is more focused to produce electricity using renewable sources towards clean energy technology.The study therefore presents a design which could possibly provide a potential to be used in wind resource assessments.Wind is commonly measured and analyzed with its scalar components separately;wind speed with anemometer and wind direction with wind vane or weather vane.The annual nature of the system of air circulation in the troposphere,affects both the wind speed and direction at a location 3.Due to their linearity and accuracy,rotational anemometers of cup and propeller type are commonly used for wind speed measurements.Though the measurements taken are usually of mean wind data,instantaneous wind measurement is also important.Instantaneous wind speed and direction data assist in analyzing the build of the turbine and tower whereas the mean wind speed data predicts wind power generation 4.Minor differences in the wind speed measurement affects the power generation greatly since the power is proportional to the cube power of the wind speed 5.So accurate wind speed measurements helps in calculating good feasibility studies for installing wind turbines.Among the different mechanisms 1 used to convert the rate of rotations to an appropriate electrical signal for recording the wind speed,four of them are commonly used which employ transducers of type DC generator,AC generator,the electrical contact and the interrupted light beam.II.LITERATURE SURVEY Previous works relating to interfacing the cup anemometer and the vane for the wind speed and direction measurement are considered as follows:Ivan Simeonov et al 6 developed an embedded system for short-term weather forecast in which the wind speed transducer gave square wave pulses whose wind speed readings needed correction for every 1 kilometer increase in altitude.Michael Cosgrove et al 7 designed an ultra-low cost logging anemometer intended for feasibility surveys of wind power generation.In this case,although the magnetic reed switch produced one pulse for single switch closure per revolution of the cups,an algorithm for debouncing was developed.Haci Can and Vedat M.Karsh 8 work in the development of a data logger using 8051 based microcontroller to measure wind speed and direction,also saw the need for signal conditioning circuitry.Yahya S.H.Khraisat 9 in his work of developing a low-cost automated system that continuously measured weather parameters the terminal voltage from DC generator type,saw the need of signal conditioning before interfacing with the microcontroller.Fouad Sh.Tahir et al 10 designed a data acquisition system based on personal computer to measure temperature,wind speed and direction parameters.Even when the wind speed transducer produced one switch closure cycle for a single rotation of the cups,a DAC was added in the circuitry for the calculation of wind speed output.David Wekesa et al 11 developed an automated,low-cost system of wind speed and direction data logger using Atmel Atmega 32 microcontroller which used optoelectronics-based system that give higher pulse rates per revolution i.e.6 to 44 12.Mehedi Al Emram et al 13 also developed a system for measuring wind speed and direction based on optoelectronics.The production of more than one pulse for a single revolution of the wind cups of the anemometer needed signal conditioning circuitry.From the above works taken into consideration,the transducers that produce the sinusoidal wave needed an additional circuit for signal conditioning or a square wave with a de bounce circuit.But this system doesnt need signal conditioning and the sensor is easily interfaced even without any de bounce circuit or de bounce algorithm or use of a DAC.The correction in the altitude is carried out by extrapolating the values of wind speed from a lower height using friction coefficient.III.HARDWARE A.Description of the Hardware The hardware primarily consists of the AT89S51 microcontroller,wind sensor or anemometer and LCD.AT89S51 is a high performing low-cost microcontroller.It is an 8-bit microcontroller with 4K bytes of In-system programmable flash memory.The on-chip flash enables the program memory to be reprogrammed either in-system or by conventional nonvolatile memory programmer.The other salient features of AT89S51 are:128 bytes of RAM,32 I/O lines and two 16bit timers/counters 14.The anemometer 15 used has a 3 hemispherical cups symmetrically held on to the vertical shaft.This design of mechanical type anemometer exerts uniform torque during revolutions.It is a passive transducer of electrical contact type that calculates the amount of air blowing in an interval of time.The device is not powered but sends out a pulse when the reed switch makes a contact on influence of the magnet.The reed switch is mounted so that it makes a single closure per revolution of the cups.The sensor includes sealed bearings for long life and can stand up to hurricane force winds although being sensitive to a light breeze with low starting threshold.Specifications of the sensor state that the range and accuracy were verified in the wind tunnel tests.The material of the cups is of light weight,versatile and eco-efficient with its operating range from less than 1 mph to over 200 miles per hour(mph).The rate of rotation of the cups is proportional to the wind blow.The weather vane that comes attached with the anemometer is flexible and has quick response to align itself pointing to the direction in which the wind blows.The vane is fitted inside with a 20k potentiometer.The vanes direction corresponding voltage is recognized and direction is displayed accordingly on the LCD.The resistance from the wiper to the terminal is completely linear with azimuth.The directions are in accordance with the meteorological wind direction.The vane pointing north starts with 0 degrees and moves clockwise through 16 points on compass rose.TABLE I.COMPASS DIRECTIONS Compass points Degree N 348.75 11.25 NNE 11.25 33.75 NE 33.75 56.25 ENE 56.25 78.75 E 78.75 101.25 ESE 101.25 123.75 SE 123.75 146.25 SSE 146.25 168.75 S 168.75 191.25 SSW 191.25 213.75 SW 213.75 236.25 WSW 236.25 258.75 W 258.75 281.25 WNW 281.25 303.75 NW 303.75 326.25 NNW 326.25 348.75 B.Hardware design The design employs the sensor unit followed by the processing unit and the display unit.Fig.1.Design of the system The processing unit consists of an ADC and AT89S51 microcontroller along with the 5V power supply circuit.The display unit has a LCD that updates the wind speed and direction information every 3 seconds.The hardware designed was estimated for wind speed calculation accuracy by using a similar output as of the wind sensor i.e.a TTL compatible square wave,from a function generator.The results are shown in the table below.TABLE II.COMPARISON OF FREQUENCY INPUT AND DISPLAYED OUTPUT Frequency given(Hz)Calculated value for 2.25 sec LCD read for 2.25 sec 3 6.75 7 5 11.25 11 10 22.5 23 20 45 45 30 67.5 67 40 90 89 65 146.25 145 78 175.5 174 85 191.25 190 98 220.5 219 100 225 224 106 238.5 237 The results compared above shows that the output from the processing unit relates well with the frequency given.The speed pulse sent by the sensor was directly interfaced with the microcontroller without the need for signal conditioning.A pull-up resistor used in the circuit ensures the signal detected by the microcontroller is always high except when the sensor pulls it low.The mechanism includes counting the pulses in a sampling period of 2.25seconds which is in accordance with the recommended sampling averaging times of 1-5 seconds for wind speed and wind direction measurements 1.The wind direction output from the sensor is connected to the controller through ADC 0804 which is a 8-bit and single channeled.The microcontroller is programmed to send out the appropriate direction according to the value at ADC.The functional circuit diagram is as follows:Fig.2.Block diagram of the circuit The photograph of the circuit is shown below.Fig.3.Circuit on board.The anemometer was fixed to a 2 foot pole and placed atop a 3-storey building for the open air measurements.The sensor was arranged at a location where there is free flow of air but could not meet the specific requirements like fixing it above 7 feet due to infrastructural constraints.However,there was an unavoidable concrete obstruction to the northeastern side of the placement.The picture below shows all the sides of the sensor.Fig.4.Anemometer placed for open air readings.IV.SOFTWARE The software was developed in C language using Keil Vision5 Integrated Development Environment(IDE)16.The hex file of the software was loaded on to the microcontroller by USB powered conventional 8051 memory programmer.The flowchart of the software is as follows:Fig.5.Wind speed and direction measurement algorithm.V.RESULTS AND DISCUSSIONS Wind measurement of speed is recorded in mph and direction by the abbreviation of the compass direction on LCD.The sensors response to the instant weather conditions appear to be flexible and accurate.The vane heeded well to any slight change in the wind direction by pointing itself into the direction of the wind.The cup anemometer moved in accordance with the wind flow.The observations were taken for three half-an-hours during the day.The readings noted for every 2 minutes were averaged to half an hour and compared with the standard values of the sonic anemometer readings from the Aerosol and Atmospheric Research Laboratory(AARL)lab set up by ISRO at Sri Krishnadevaraya University(SKU).The standard readings at 10m height as well as the observed values at 16m height are tabulated below:TABLE III.STANDARD AND OBSERVED VALUES OF WIND SPEED AND DIRECTION Hr Standard WS10m(m/s)Observed WS16m(m/s)Standard WDir10m Observed WDir16m(Compass points)16.5 1.5267 1.69875 68.5148(ENE)ENE 17.0 1.8173 2.01168 76.0462(ENE)ENE 17.5 1.8193 2.06756 92.9933(E)E Wind Rose graphs plotted using Oriana 4 software are shown below:Fig.6.Wind direction resultant mean at ENE for 16:00 to 16:30.Fig.7.Wind direction resultant mean at ENE during 16:30 to 17:00.Start Include suitable header files Define ports Initialize LCD Set Timer 1 to count 8-bit value Start counting pulses for the sampling period and stop the counter Display the wind run on LCD Read the wind direction digital output from ADC Select the wind direction according to the analog voltage and display on LCD Do it for ever Fig.8.Wind direction resultant mean at E during 17:00 to 17:30 A few points of the results are:?Easterly wind blew for most of the time during the half an hour between 16hr to 16hr 30 min forming 50%of the total while the resultant mean is towards East-North east.?During the 16:30 to 17:00 time period,higher wind speeds were observed along East-Northeast and East direction with high frequency wind blowing from the East even for next half an hour.?The obstruction on north-western side impacted little on the observations due to easterly wind blowing for most of the time and the wind direction readings coincided exactly with that of the standard readings.?The wind speeds as observed at 16m are higher as expected with the wind speed measured at 10m.?The dead band error is present from 0o to 5o and from 355o to 360o.But the latter part of the error was eliminated by programming.The standard values of wind speed at height of 10m are extrapolated to the height of 16m at which the observed values relate.For extrapolation the power law 17 proposed by Hellmann is used.The equation is v/v0 =(H/H0)(1)Where v is the the speed at height H,v0 is the speed at height H0(frequently referred to as a 10-meter height)and is the friction coefficient or Hellmann exponent or wind shear coefficient 18.This coefficient is a function of the particular topography at a site,and this parameter can vary by the hour of the day,time of the year and with atmospheric conditions such as air density.The table 17 shown below relates the friction coefficient for a variety of landscapes.TABLE IV.FRICTION COEFFICIENT TABLE FOR DIFFERENT LANDSCAPES.Landscape type Friction coefficient()Lakes,ocean and smooth hard ground 0.10 Grasslands(ground level)0.15 Tall crops,hedges and shrubs 0.20 Heavily forested land 0.25 Small town with some trees and shrubs 0.30 City areas with high rise buildings 0.40 The friction coefficient is calculated by rewriting(1),as =(ln(v)ln(v0)/(ln(H)ln(H0)(2)According to the standard wind data from 15Hrs to 15.5Hrs on 1st April,2016 the wind speed(v)at 18m height is 1.4704m/s and at 10m height,the wind speed(v0)is 1.39m/s.From(2),the friction coefficient for these values is 0.1.But the observations were taken on the same day from 16Hr to 17Hr 30min which was toward evening when the temperature fall and the friction coefficient increase.So the next two friction coefficients i.e.0.15 and 0.20 were taken into consideration for extrapolating the standard reading from 10m to 16m height.The results are tabulated as below.TABLE V.EXTRAPOLATED STANDARD VALUES AND OBSERVED WIND SPEED READINGS S.No Time of the day(Hrs)WS(m/s)=0.15 WS(m/s)=0.20 Observed WS(m/s)1 16.5 1.6382 1.6771 1.69875 2 17 1.9499 1.9964 2.01168 3 17.5 1.9521 1.9986 2.06756 The extrapolated standard wind speed readings for both the friction coefficients of equal to 0.15 and 0.20 strongly correlated with the observed values of wind speed.The correlation coefficients are 0.99091 and 0.99089 respectively.The easterly wind blowing for most of the time did not have any apparent obstructions as can be seen from Fig.4.Moreover,a little higher observed wind speed values can be accounted for the wind speed acceleration that occurs over hills,buildings etc(when the wind encounters an obstruction)17.The power management however is relatively short for the use of long term observations of wind data.VI.CONCLUSION The system developed using AT89S51 microcontroller and Davis Anemometer 6410 to measure real-time wind speed and wind direction showed fairly accurate results which were corroborated by the standard values from the Aerosol and Atmospheric Research Laboratory at SKU,taken during the same hours on the same day.The strong correlation coefficients obtained showed that the system can be a reliable one.References 1 USA Environmental Protection Agency(EPA).“Meteorological Monitoring Guidance for Regulatory Modeling Applications”,February 2000.EPA-454/R-99-005.2 http:/ 3 http:/green-.pl/en/home/wiatr-i-jego-pomiar-w-energetyce-wiatrowej/4 http:/ 5 http:/www.wwindea.org/technology/ch01/en/1_4.html 6 I.Simeonov,H.Kilifarev,R.Llarionov,“Embedded system for short-term weather forecasting”,Proceedings of International Conference on Computer Systems and Technologies(CompSysTech06),2006.7 M.Cosgrove,B.Rhodes,J.Scott,“Ultra-low-cost Logging Anemometer for Wind Power Generation Feasibility Surveys”,Research Gate,January 2007.8 H.Can,V.M.Karsh,“Multipoint Wind speed and direction measurement and data logging by using 8051-based microcontroller”,American Journal of Science,157:2482-2488,2007.9 Yahya S.H.Khraisat,“Design a Wireless Meteorological Station in Jordan”,Canadian Center of Science and Education,vol.5,no.1,January 2012.10 F.S.Tahir,A.M.Salman,J.K.Mohammed,W.K.Ahmed,“Data Acquisition System for Wind Speed,Direction and Temperature Measurements”,Journal of Engineering,vol.18,no.11,pp.1229-1236,November 2012.11 D.W Wekesa,J.N.Kamau,J.N.Mutuku,“Calibrated data logging instrumentation system for wind speed and direction measurements”,Basic Research Journal of Engineering Innovation,vol.1(3),pp.53-57,June 2013.12 S.Pindado,J.Cubas,F.Sorribes-Palmer,“The Cup Anemometer,a Fundamental Meteorological Instrument for the Wind Energy Industry.Research at the IDR/UPM Institute”,Sensors,vol.14,pp.21428-21452,August 2014.13 http:/documents.mx/documents/a-microcontroller-based-system-for-determining-instantaneous-wind-speed-and.html 14 AT89S51 Datasheet.pdf.15 Davis Anemometer 6410 Datasheet.pdf.16 http:/ 17 F.Banuelos-Ruedas,C.A.Camacho,S.Rios-Marcuello.“Methodologies used in its impact in the Wind Energy Resource Assessment in a Region”.Available: 18 Firas A.Hadi,“Diagnosis of the Best Method for Wind Speed Extrapolation”,International Journal of Advanced Research in Electrical,Electronics and Instrumentation Engineering.vol.4,no.10,October 2015.