自動(dòng)跟蹤太陽智能型太陽能系統(tǒng)設(shè)計(jì)[機(jī)電-PLC]【三菱】【8張cad圖紙+文檔全套資料】

喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== 喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== XXXXX大學(xué) 畢業(yè)設(shè)計(jì)（論文）開題報(bào)告 題 目 自動(dòng)跟蹤太陽智能型太陽能系統(tǒng)設(shè)計(jì) 系 部 XXXXXX 專 業(yè) XXXXXX 學(xué)生姓名 XXXX 學(xué)號(hào) XXXXX 指導(dǎo)教師 XXXXX 職稱 XXXXX 畢設(shè)地點(diǎn) 2013年 2月24日 設(shè)計(jì)（論文） 題目 自動(dòng)跟蹤太陽智能型太陽能系統(tǒng)設(shè)計(jì) 一、 本課題的研究目的和意義 太陽能是已知的最原始的能源，它干凈、可再生、豐富，而且分布范圍廣，具有非常廣闊的利用前景。但太陽能利用效率低，這一問題一直影響和阻礙著太陽能技術(shù)的普及，如何提高太陽能利用裝置的效率，始終是人們關(guān)心的話題，太陽能自動(dòng)跟蹤系統(tǒng)的設(shè)計(jì)為解決這一問題提供了新途徑，從而大大提高了太陽能的利用效率。 太陽能以其不竭性和環(huán)保優(yōu)勢(shì)已成為當(dāng)今國內(nèi)外最具發(fā)展前景的新能源之一。光伏（PV）發(fā)電技術(shù)在國外已得到深入研究和推廣,我國在技術(shù)上也已基本成熟，并已進(jìn)入推廣應(yīng)用階段。但太陽能存在著密度低、間歇性、光照方向和強(qiáng)度隨時(shí)間不斷變化的問題，這對(duì)太陽能的收集和利用裝置提出了更高的要求。目前很多太陽能電池板陣列基本上都是固定的，不能充分利用太陽能資源，發(fā)電效率低下。如果能始終保持太陽能電池板和光照的垂直，使其最大化地接收太陽能，則能充分利用豐富的太陽能資源。根據(jù)據(jù)實(shí)驗(yàn)，在太陽能發(fā)電中，相同條件下，采用自動(dòng)跟蹤發(fā)電設(shè)備要比固定發(fā)電設(shè)備的發(fā)電量提高35 %左右。因此，設(shè)計(jì)開發(fā)能自動(dòng)追蹤太陽光照的控制系統(tǒng)，是非常有價(jià)值的研究課題。 太陽能是一種低密度、間歇性、空間分布不斷變化的能源，這就對(duì)太陽能的收集和利用提出了更高的要求。目前，提高太陽能利用率的研究主要集中在兩方面：一方面是提高太陽能裝置的能量轉(zhuǎn)換率，另一方面是提高太陽能的集熱率；前者屬于能量轉(zhuǎn)換領(lǐng)域，還有待研究，而后者利用現(xiàn)有的技術(shù)則可解決【1】。無論哪種太陽能利用設(shè)備，如果它的采光裝置能自動(dòng)追蹤太陽并始終保持與太陽光垂直，它就可以在有限的使用面積內(nèi)收集更多的太陽能。太陽能電池發(fā)電原理：利用光伏發(fā)電，即通過一對(duì)有光響應(yīng)的器件將光能轉(zhuǎn)換成電能。太陽能電池板的發(fā)電量與太陽光入射角器件將光能轉(zhuǎn)換成電能。太陽能電池板的發(fā)電量與太陽光入射角器件將光能轉(zhuǎn)換成電能。太陽能電池板的發(fā)電量與太陽光入射角有關(guān)，當(dāng)太陽光線與太陽電池板平面垂直時(shí)轉(zhuǎn)換率最高。采用自動(dòng)追光系統(tǒng)轉(zhuǎn)換率可提高40%。 因此在這樣一個(gè)大前提下，我們需要制作一套全自動(dòng)太陽能追光系統(tǒng)，實(shí)現(xiàn)了最大限度地使用太陽能，相信在不久的將來，它可以真正用到實(shí)處，用到人們的日常生活中去 二、 國內(nèi)外研究情況及其發(fā)展 太陽輻照追蹤裝置要對(duì)應(yīng)于晝夜、陰晴更替。太陽落山時(shí)，追蹤裝置朝向西邊，然后停止工作，并能夠復(fù)位；當(dāng)遇到烏云遮住太陽時(shí)，追蹤裝置傳感單元無法反應(yīng)出太陽光線的變化，當(dāng)烏云過后太陽可能偏離較大的角度，這種情況下就要求追蹤裝置傳感探測(cè)單元能夠在較大的范圍內(nèi)反應(yīng)出太陽光線的變化。 現(xiàn)有用于太陽觀測(cè)科學(xué)研究的太陽追蹤裝置雖然追蹤準(zhǔn)確但是價(jià)格太昂貴，如國家氣象計(jì)量站研制的FST型全自動(dòng)太陽跟蹤器采用傳感器定位和太陽運(yùn)行軌跡定位相結(jié)合的設(shè)計(jì)彌補(bǔ)了赤道架型太陽跟蹤器的缺點(diǎn)，具有全自動(dòng)、全天候、跟蹤精度高等優(yōu)點(diǎn) 。這種大型精密儀器由于價(jià)格昂貴，通用性和性價(jià)比不高。 普通民用太陽追蹤裝置比如1997年美國Blackace研制的單軸太陽跟蹤器，完成了東西方向的白動(dòng)跟蹤，而南北方向則通過手動(dòng)調(diào)節(jié)，接收器的熱接收率僅提高了15% 。1998年美國加州成功的研究了ATM兩軸跟蹤器，該裝置在太陽能面板上裝有集中陽光的涅耳透鏡，這樣可以使小塊的太陽能面板硅收集更多的能量，使熱接收率進(jìn)一步提高。JoeI.H.Goodman研制了活動(dòng)太陽能方位跟蹤裝置，該裝置通過大直徑回轉(zhuǎn)臺(tái)太陽能接收器可從東到西跟蹤太陽，這個(gè)方位跟蹤器具有人直徑的軌跡，通風(fēng)窗體是白晝光照鼓膜結(jié)構(gòu)窗體，窗體上面是圓頂結(jié)構(gòu)，成排的太陽能收集器可以從為、到西跟蹤太陽，以提高夏天季節(jié)里能量的獲取率。2002年2月美國亞利桑那大學(xué)推出了新型太陽能跟蹤裝置，該裝置利用控制電機(jī)完成跟蹤，采用鋁型材框架結(jié)構(gòu)，結(jié)構(gòu)緊湊，重量輕，大大拓寬了跟蹤器的應(yīng)用領(lǐng)域。這些普通民用太陽追蹤裝置，普遍存在的問題是精度差。 市場(chǎng)急需一種追蹤范圍廣、精度高，原理結(jié)構(gòu)簡單、方便使用的太陽追蹤裝置，并盡快將一技術(shù)轉(zhuǎn)化為生產(chǎn)力，從而推動(dòng)太陽能的普及利用，拓寬太陽能的利用領(lǐng)域。 三、 本課題的主要研究內(nèi)容（提綱） 本文所介紹的太陽跟蹤裝置采用了光電追蹤方式，可實(shí)現(xiàn)大范圍、高精度跟蹤。論文的主要工作包括: (l)分析太陽運(yùn)行規(guī)律，比較國內(nèi)外主要的幾種跟蹤方案，提出合理的跟蹤策略。 (2) 機(jī)械部分也是實(shí)現(xiàn)追蹤目的的關(guān)鍵，主要是機(jī)械設(shè)計(jì)和計(jì)算，裝配圖及其零件圖。 (3)分析傳感器工作原理，分析該傳感器大范圍、高精度跟蹤的可行性，還要設(shè)計(jì)光電轉(zhuǎn)換電路。 (4)選取控制方案，分析系統(tǒng)的硬件需求，設(shè)計(jì)控制系統(tǒng)。 (5)設(shè)計(jì)控制方案，伺服電機(jī)以及驅(qū)動(dòng)電路。 四、 研究思路和方法 本課題主要研究太陽追蹤器，課題要求通過對(duì)產(chǎn)品結(jié)構(gòu)的分析，制定出幾種結(jié)構(gòu)方案，通過對(duì)多種方案的比較，選擇比較合理的方案進(jìn)行設(shè)計(jì)，并進(jìn)行相關(guān)的工藝設(shè)計(jì)計(jì)算，使之具有實(shí)用性和經(jīng)濟(jì)性方面的要求。 主要思路：首先認(rèn)真分析產(chǎn)品結(jié)構(gòu)，確定設(shè)計(jì)方案； 其次，小組成員間分工合作，充分發(fā)揮團(tuán)隊(duì)作用，將數(shù)據(jù)匯總分析，及時(shí)對(duì)方案進(jìn)行修改，提高設(shè)計(jì)效率；最后，對(duì)產(chǎn)品的工程圖進(jìn)行繪制和裝配，觀察各部件間是否有運(yùn)動(dòng)干涉，避免在現(xiàn)實(shí)中發(fā)生事故。最后，對(duì)控制方案進(jìn)行比較，最后選取最為適合的控制方案，完成控制系統(tǒng)的設(shè)計(jì)。 主要方法：充分運(yùn)用計(jì)算機(jī)輔助設(shè)計(jì)，實(shí)現(xiàn)二維圖的繪制和裝配圖的繪制，同時(shí)了解PLC控制器的特點(diǎn)，編寫控制程序。 五、 本課題的進(jìn)度安排 起訖日期：2012年12月8日至2013年6月10日 進(jìn)度安排：2012年12月～2013年01月 查閱資料，了解所要做的內(nèi)容，學(xué)習(xí)有關(guān)太陽追蹤器的資料。 2012年01月～2013年02月 運(yùn)用查閱的資料知識(shí)，選擇設(shè)計(jì)方案。 2013年02月～2013年03月 完善方案選擇，準(zhǔn)備開題報(bào)告。 2013年03月～2013年04月 翻譯文獻(xiàn),準(zhǔn)備期中檢查。 2013年04月～2013年05月 條件允許，去公司考察研究。 2013年05月～2013年06月 寫畢業(yè)論文，并裝訂成冊(cè)，準(zhǔn)備畢業(yè)答辯。 2013年06月初期 論文形式、內(nèi)容審閱, 畢業(yè)答辯，上交資料 六、 參考文獻(xiàn) [1]李申生．太陽能[M]．北京：北京人民教育出版社，1988:12-14. [2]王炳忠．太陽能—未來能源之星[M]．北京：高教出版社，1990:20-21. [3]徐文燦，袁俊等．太陽能自動(dòng)跟蹤系統(tǒng)的探索與實(shí)驗(yàn)[J]．物理實(shí)驗(yàn)，2003，23(9)：45-48. [4]練亞純．太陽能的利用[M]．北京：北京人民出版社，1975:24-25. [5]言惠．太陽能21世紀(jì)的能源[J]．上海大中型電機(jī)，2004，(04):16-18. [6]姚偉．太陽能利用與可持續(xù)發(fā)展[J]．中國能源，2005，(02):05-06. [7]張順心，宋開峰，范順成等．基于并聯(lián)球面機(jī)構(gòu)的太陽跟蹤裝置研究[J]．河北工業(yè)大學(xué)學(xué)報(bào)， 2003，32(6)：44-47． [8]戴聞．太陽能利用前景光明[J]．物理，2003，(08):9-14. [9]郭廷瑋．太陽能的利用[M]．上海：科學(xué)技術(shù)文獻(xiàn)出版社，1984:31-33. [10]胡勛良，強(qiáng)建科，余招陽等．太陽光跟蹤器及其在采光中的應(yīng)用[J]．電子技術(shù)(上海)，2003，30(12)：8-10. [11]余海．太陽能利用綜述及提高其利用率的途徑[J]．能源研究與利用，2004，(03):2-7. [12]呂春生．日本的新能源開發(fā)及對(duì)我國的啟示[J]．現(xiàn)代日本經(jīng)濟(jì)，2006，(06): 37-41. [13]張明.德國太陽能發(fā)電最多的國家[R]．廣西電力建設(shè)科技信息,2004，(04):51-52. [14]周惠．美國有關(guān)可再生能源和節(jié)能情況考察報(bào)告[R]．可再生能源，2007，25（1），98-101. [15]徐機(jī)玲，蔡玉高．太陽能利用新突破[J]．瞭望，2004，(39):28-30. [16]胡賽純，湯青云．太陽能利用現(xiàn)狀與趨勢(shì)[J]．湖南城建高等?？茖W(xué)校學(xué)報(bào)，2003，(01)：08-12. [17]孫孝仁．太陽能利用的現(xiàn)狀與未來[J]．山西省科技情報(bào)研究所，2005，（08）：15-14. [18] 張艷紅，張崇巍，呂紹勤，張興等．新型太陽能控制器的研制[J]．節(jié)能，2006，(02):09-15. [19]李建庚，呂文華， 曉雷等．一種智能型全自動(dòng)太陽跟蹤裝置的機(jī)械設(shè)計(jì)[J]．太陽能學(xué)報(bào)，2003，24(03)：330-333． [20] 樓然苗.51系列單片機(jī)設(shè)計(jì)實(shí)例.北京:北京航空航天大學(xué)出版社，2003 [21] 楊培環(huán) 高精度太陽跟蹤傳感器與控制器研究 2010年4月 [22] 王淑英等編第四版電氣控制與PLC應(yīng)用 指導(dǎo)教師意見 指導(dǎo)教師（簽名）： 年 月 日 所在系（所）意見 負(fù)責(zé)人（簽章）： 年 月 日 附錄1 Solar Tracker David Crowe, Jeff McCormick, Joel Mitchell, Thomas Stratton, Jeff Schwane December 15, 2005 Duke University Smart House Pratt School of Engineering Abstract The Solar Tracker team was formed in the fall of 2005 from five students in an ME design team, and a Smart House liaison. We continued the work of a previous solar tracker group. The task was to design a prototype tracking device to align solar panels optimally to the sun as it moves over the course of the day. The implementation of such a system dramatically increases the efficiency of solar panels used to power the Smart House. This report examines the process of designing and constructing the prototype, the experiences and problems encountered, and suggestions for continuing the project. 1.Introduction Solar tracking is the process of varying the angle of solar panels and collectors to take advantage of the full amount of the sun’s energy. This is done by rotating panels to be perpendicular to the sun’s angle of incidence. Initial tests in industry suggest that this process can increase the efficiency of a solar power system by up to 50%. Given those gains, it is an attractive way to enhance an existing solar power system. The goal is to build a rig that will accomplish the solar tracking and realize the maximum increase in efficiency. The ultimate goal is that the project will be cost effective – that is, the gains received by increased efficiency will more than offset the one time cost of developing the rig over time. In addition to the functional goals, the Smart House set forth the other following goals for our project: it must not draw external power (self-sustaining), it must be aesthetically pleasing, and it must be weatherproof. The design of our solar tracker consists of three components: the frame, the sensor, and the drive system. Each was carefully reviewed and tested, instituting changes and improvements along the design process. The frame for the tracker is an aluminum prismatic frame supplied by the previous solar tracking group. It utilizes an ‘A-frame’ design with the rotating axle in the middle. Attached to the bottom of this square channel axle is the platform which will house the main solar collecting panels. The frame itself is at an angle to direct the panels toward the sun (along with the inclination of the roof). Its rotation tracks the sun from east to west during the day. The sensor design for the system uses two small solar panels that lie on the same plane as the collecting panels. These sensor panels have mirrors vertically attached between them so that, unless the mirror faces do not receive any sun, they are shading one of the panels, while the other is receiving full sunlight. Our sensor relies on this difference in light, which results in a large impedance difference across the panels, to drive the motor in the proper direction until again, the mirrors are not seeing any sunlight, at which point both solar panels on the sensor receive equal sunlight and no power difference is seen. After evaluation of the previous direct drive system for the tracker, we designed a belt system that would be easier to maintain in the case of a failure. On one end of the frame is a motor that has the drive pulley attached to its output shaft. The motor rotates the drive belt which then rotates the pulley on the axle. This system is simple and easily disassembled. It is easy to interchange motors as needed for further testing and also allows for optimization of the final gear ratio for response of the tracker. As with any design process there were several setbacks to our progress. The first and foremost was inclement weather which denied us of valuable testing time. Despite the setbacks, we believe this design and prototype to be a very valuable proof-of-principle. During our testing we have eliminated many of the repetitive problems with the motor and wiring so that future work on the project will go more smoothly. We also have achieved our goal of tracking the sun in a ‘hands-off’ demo. We were able to have the tracker rotate under its own power to the angle of the sun and stop without any assistance. This was the main goal set forth to us by the Smart House so we believe our sensed motion prototype for solar tracking will be the foundation as they move forward in the future development and implementation of this technology to the house. 2. Defining the Problem The project was to complete the “REV 2” design phase of the solar tracker to be used on the Smart House. While the team was comprised of members from the ME160 senior design course, the customer for this project was to be the Smart House organization. Jeff Schwane, a representative from the Smart House, was our liaison and communicated to our group the direction Smart House leadership wished us to proceed. At our first meeting with Jeff and Tom Rose, the following needs were identified: 1. Track the sun during the day 2. Use no external power source 3. Weather proof 4. Cost effective power gain 5. Must look good 6. Solar panel versatile i.e. can fit different types of panels With these needs in hand, we constructed a Quality Function Deployment chart. This chart can be found in Appendix A. The QFD showed the major areas of concern might have been: number of panels/size of panels, internal power requirements, motor torque required. At our first meeting we were also able to set up our goals for the semester. Having a working prototype capable of tracking the sun was to be the main goal for the end of the semester, but we soon found that in order to accomplish this, we would be forced to omit portions of the design criteria in hopes they would be worked out later. This would result in the optimization of platform space on the roof to be irrelevant, with our goal being to have one platform track. It also led to the assumption that our base would not need to be tested for stability or required to be fastened to the roof. With an idea of where we were to begin, from scratch with the possibility of using the frame from the “REV 1” design, and an idea of where we were to finish, with a moving prototype, we constructed the Gantt chart that can be found in Appendix B. Our group planned to meet with Jeff once a week to make sure we were on track with the needs of the Smart House. Jeff would also meet with Tom Rose, the director of Smart House, at least once a week in order to keep everyone on the same page. With our goals in mind we embarked on the process of idea generation. 3. Concepts and Research 3.1 Tracking Type Our group used a brainstorming approach to concept generation. We thought of ideas for different solar tracking devices, which proved difficult at times due to the existing frame and concept presented to us by Smart House. Other concepts were generated through research of pre-existing solar tracking devices. Originally our concept generation was geared towards creating a completely new solar tracker outside of the constraints of the previous structure given to us by Smart House. This initial brainstorming generated many concepts. The first one was a uni-axial tracking system that would track the sun east to west across the sky during the course of a day and return at the end of the day. This concept presented the advantage of simplicity and presented us with the option to use materials from the previous structure (which was also intended to be a uni-axial tracker) in construction. Another more complex concept was to track the sun bi-axially which would involve tracking the sun both east to west and throughout the seasons. The advantage of this concept was a more efficient harvesting of solar energy. The third concept was to only track throughout the seasons. This would provide small efficiency gains but nowhere near the gain provided by tracking east to west. The different structures we came up with to accomplish tracking motion included a rotating center axle with attached panels, hydraulic or motorized lifts which would move the main panel in the direction of the sun, and a robotic arm which would turn to face the sun. The clear efficiency gains coupled with the simplicity of design of the uni-axial tracking system and the existence of usable parts (i.e. motor and axle) for the rotating center axle structure, led us to the choice of the East to West tracking, rotating center axle concept. 3.2 Structure Once the method of motion was chosen, it was necessary to generate concepts for the structural support of the axle. Support could be provided by the triangular prismatic structure which was attempted by the previous Smart House solar tracker group or through the use of columns which would support the axis on either side. While the prismatic structure presented the advantage of mobility and an existing frame, the columns would have provided us with ease of construction, simple geometric considerations, and ease of prospective mounting on the roof. Due to the heightened intensity of time considerations, the previous financial commitment to the prismatic structure by Smart House, and our limited budget, the presence of the pre-existing frame proved to be the most important factor in deciding on a structure. Due to these factors we decided to work within the frame which was provided to us from the previous Solar Tracker group. 3.2 Tracking Motion Once the structural support was finalized we needed to decide on a means to actualize this motion. We decided between sensed motion, which would sense the sun’s position and move to follow it, and continuous clock type motion, which would track the sun based on its pre-determined position in the sky. We chose the concept of continuous motion based on its perceived accuracy and the existence of known timing technology. During the evaluation stage, however, we realized that continuous motion would prove difficult. One reason was the inability to draw constant voltage and current from the solar panels necessary to sustain consistent motion, resulting in the necessity for sensing the rotation position to compensate. Continuous motion also required nearly constant power throughout the day, which would require a mechanism to store power. Aside from these considerations, the implementation of a timing circuit and location sensing device seemed daunting. After consulting Dr. Rhett George, we decided on a device using two panels and shading for sensed motion. 4. Analysis and Embodiment 4.1 Structure Geometry The geometry of the frame was created in order to allow the solar panels to absorb light efficiently. This was done by allowing rotation in the east-west direction for tracking the sun daily and a 36° inclination (Durham’s latitude) towards the south. Because this frame was designed to be placed on a roof with a slope of 25°, the actual incline of the frame was made to be 11°. The geometry of the existing platform structure was modified. This was done in order to incorporate the results from the Clear Day Model supplied to us by Dr. Knight. This model led to the conclusion that the platform should track to up to 60° in both directions of horizontal. Thus, the angle range of the frame had to be increased. The sides of the frame were brought in to increase the allowable angle of rotation, and they were brought in proportionally to maintain the inclination angle of 11°. Also, crosspieces were moved to the inside of the frame to allow greater rotation of the platform before it came into contact with the support structure. The panels used for sensing and powering rotation were placed on the plane of the platform. Mirrors were placed perpendicular to and in between the panels to shade one and amplify the other in order to produce a difference to power the motor. The sensing panels were placed outside the platform area to maintain the largest area possible for collecting panels. A third sensing panel was mounted nearly vertical and facing east to aid rotation back towards the sun in the morning. This panel was attached to the frame under the platform, so that during most of the day, it’s shaded with minimal effects on sensed rotation. Minimizing the torques on the motor was a main concern in order to minimize the motor power needed. The platform designed for the placement of the collecting solar panels was placed under the rotational shaft so that the panels would be aligned with it the rotational axis. Since the main panels comprise the majority of the weight putting these in the plane of the rotational axis reduces torque on the shaft. The sensing panels were placed symmetrically about the axis of rotation in order to prevent additional torque on the motor. The third panel was attached to the frame instead of the platform or rotational shaft so as to also avoid any torque. 4.2 Materials Materials selection for most of the frame was simple because it had already been constructed. The mirrors used for the amplification and shading of the sensing panels were also already purchased and available for use. Additional parts for attachment of the panels and mirrors to the frame were taken from the scrap pieces available in the machine shop. In our selection of sensing panels, size and power needed to be balanced effectively. The panels were to be as small as possible in order to add minimal stress and weight to the frame but also needed to be powerful enough to power the rotation of the platform. Therefore, the most powerful of the intermediate sized panels available were selected. The panels purchased also appeared to be the most reliable of our options. 4.3 Drive Mechanism After designing a prototype and testing it, the motor purchased and used by the previous solar tracker group was slipping. It was removed, and the installation of a gear system with another simple motor was suggested and attempted. Professor Knight supplied some gears as well as some belts and pulleys. One end of the shaft was lathed so that one of the pulleys could be set on it, and spacers were bought so that a 6V motor we had available could power another pulley. These pulleys were to be connected by a belt. This motor demonstrated insufficient strength to turn the rotational shaft. The original motor, once detached, was taken apart and examined. Itappeared to be working again so a new pulley was purchased to fit it and was attached in the place of the 6V motor. 5. Detailed Design 5.1 Frame The frame was designed from one inch square aluminum tubing, and a five foot long, two inch square tube for the axle. It is constructed with a rigid base and triangular prismatic frame with side supporting bars that provide stability. The end of the axle is attached to a system of pulleys which are driven by the motor. It is easily transported by removing the sides of the base and folding the structure. 5.2 Sensor Our sensing panels are bolted to the bottom of the main solar panel frame and braced underneath with half inch L-brackets. The mirrors are attached to the inside of the sensing panels and braced by L-brackets as well. The whole structure attaches easily to the main panel frame which is attached to the main axle using four 2-inch U-bolts. A third panel is bolted to the structure to return the main panels direction towards the horizon of sunrise. 5.3 How the Sensor Works Our sensor creates movement of the motor by shading one of the panels and amplifying the other when the system is not directly facing the sun. The two sensing panels are mounted parallel to the main panels symmetrically about the center axle with two mirrors in between them. The shading on one of the panels creates high impedance, while the amplified panel powers the motor. This happens until the panels receive the same amount of sunlight and balance each other out (i.e. when the sensing panels and main panels are facing the sun.). We initially attempted using a series configuration to take advantage of the voltage difference when one of the panels was shaded (Appendix C). This difference, however, was not large enough to drive the motor. We subsequently attempted a parallel configuration which would take advantage of the impedance of the shaded panel (Appendix C) and provide the current needed to drive the motor. Once the sensing mechanism has rotated from sunrise to sunset, the third panel, which is usually shaded, uses sunlight from the sunrise of the next day to power the motor to return the panels towards the direction of the sun. 6. Prototype Testing Initial testing was done using just the sensing component and a 6V motor. The panels were tilted by hand to create shading and amplification. A series configuration of the sensing panels was initially tested and proved ineffective. Data acquisition showed a maximum of a 2V difference across the motor, which was insufficient to power it. Upon testing the panels individually, it was discovered that the open voltage across each individual panel would only vary between 21.5V and 19.5V when fully amplified and fully shaded, respectively. The current running through each panel, however, was seen to fluctuate between nearly 0 amps when shaded, up to 0.65 amps when fully amplified. Therefore, in order to take advantage of the increase in impedance of the solar panels due to shading, we chose to put our sensing panels in parallel with each other and the motor. Tests with this configuration turned the motor in one direction, stopped when the sensing panels were nearly perpendicular to the sun, and reversed direction as the panels rotated past perpendicular. We found the angle range necessary to stop the motor to be very small. It was also observed that the panels rotated to slightly past perpendicular when they ceased motion. This error may be due to a difference in the innate resistance in each individual sensing panel. When tested it was found that one panel had a resistance of 52 kΩ, and the other panel resistance was 53 kΩ. Other testing found the voltage and current provided by the sensing solar panels to the motor to be consistent at all points, excluding when the solar panels are directly facing the sun. Through testing it was concluded that resistance may need to be added to one of the panels to compensate for the differences in the internal resistances of the individual panels, and a voltage regulator needs to be added to decrease the voltage seen across the motor. The original motor was prone to failure as its slippage caused the breakdown of our initial prototype after testing. This led to the institution of the pulley and belt driven system which would allow for easier maintenance given motor failure or slippage. The success of our initial testing and prototype proved to us the efficacy of our solar tracker design. 7. Conclusion Throughout this project we enlisted the support of multiple resources (i.e. ME and EE professors, previous Smart House teams). We learned early on that a clear problem definition was essential to efficient design and progress. We struggled initially as we tried to design a tracking device that was different from the previous solar tracker group’s attempt, without fully weighing the size of their investment and the advantages of using the existing frame for our purposes. As we worked with the fixed frame construction from the previous group we learned that variability of design is key, especially when in the initial phases of prototyping. After many setbacks in testing of the solar panels, we learned that when working with solar panels, much time needs to be set aside for testing due to the unpredictability of the weather. The actual implementation of using the prototype in its intended location on the Smart House roof requires weather-proofing to protect the wiring and electrical connections from the elements, housing for the motor, a bracing system to attach the structure to the roof, and possible redesign to