毕业论文-串联超前矫正装置的设计.doc

1 学 号 （自动控制原理课程设计） 设计说明书 串联超前矫正装置的设计串联超前矫正装置的设计 起止日期： 2015 年 7 月 06 日 至 2014 年 7 月 10 日 学生姓名 班级 成绩 指导教师 (签字 ) 控制与机械工程学院控制与机械工程学院 2015 年年 7 月月 5 日日 2 目录目录 一、绪论一、绪论1 二、原系统分析二、原系统分析.1 2.12.1 原系统的单位阶跃响应曲线原系统的单位阶跃响应曲线.1 2.22.2 原系统的原系统的 BodeBode 图图2 2.32.3 原系统的原系统的 NyquistNyquist 曲线曲线3 2.42.4 原系统的根轨迹原系统的根轨迹3 三、校正装置设计三、校正装置设计.4 3.13.1 校正装置参数的确定校正装置参数的确定4 3.23.2 校正装置的校正装置的 bodebode 图图5 四、校正后系统的分析四、校正后系统的分析5 4.14.1 校正后系统的单位阶跃响应曲线校正后系统的单位阶跃响应曲线.5 4.24.2 校正后系统的校正后系统的 BodeBode 图图5 4.34.3 校正后系统的校正后系统的 NYQUISTNYQUIST 曲线曲线 5 4.44.4 校正后系统的根轨迹校正后系统的根轨迹 6 五、总结五、总结6 六、参考文献六、参考文献 6 七、附图七、附图7 3 一、绪论 概述超前或滞后校正的优缺点和适用范围 串联超前校正的基本原理：利用超前网络的相角超前特性。只要正确的将超前网 络的交接频率 1/aT 和 1/T 选择在带校正系统截止频率的两旁，并适当选取参数 a 和 T,就 可以校正系统的截止频率和相角裕度满足性能指标的要求，从而改善系统的动态性能。 串联超前校正的优点：保证低频段满足稳态误差，改善中频段，使截止频率增大， 相角裕度变大，动态性能提高，高频段提高使其抗噪声干扰能力降低。 有些情况下采用串联超前校正是无效的，它受到以下两个因素的限制： 1. 闭环宽带要求。若待校正系统不稳定的话，为了得到规定的相角裕度，需要超前网 络提供很大的相角超前量。这样的话，超前网络的 a 值必须选取的很大，从而造成 已校正系统带宽过大，使得通过系统的高频噪声电平很高，很可能使系统失控。 2. 在截至频率附近相角迅速减小的待校正系统，一般不宜采用串联超前校正。因为随 着截止频率的增大，待校正系统相角迅速减小，使已校正系统的相角裕度改善不大， 很难得到足够的相角超前量，在一般情况下，产生这种相角迅速减小的原因是，在 待校正系统的截止频率附近，或有交接频率彼此靠近的惯性环节；或由两个交接频 率彼此相等的惯性环节；或有一个震荡环节。 二、原系统分析二、原系统分析 2.1 原系统的单位阶跃响应曲线原系统的单位阶跃响应曲线 单位反馈系统的开环传递函数，所以单位反馈系统的 (s)=C(S)/R(s), ) 1( 15 )( ss sG R(S)=1/s,所以 ,经过拉斯反变换得到 C（t）的图像，应用 Matlab 可 )1( 15 )( s sC 绘制出开环系统阶跃响应曲线见图一，由图可得相角裕度，截止频率 7.14 ，不满足条件，所以用串联超前矫正装置的设计。srad/81.3 由图可得 ts=3s；ess=0，tp=1s 校正前单位阶跃响应 MATLAB 程序如下： num=15; den=1 1 0; sys=tf(num,den); sys1=feedback(sys,1); t=0:0.1:45; 4 step(sys1,t) hold on grid hold off 2.2 原系统的原系统的 Bode 图图 a 确定各交接频率 及斜率变化值 最小相位惯性环节：1=1， 斜率减小 20db/dec; 最小交接频率： 1=1 b 绘制频段（min）渐进特性曲线。 有 20（20/w）讲 w=0.1 带入，得知过点（1,20200），斜率为-20de/dec. C 绘制频段(min)渐进特性曲线 0.11, k=-20db/dec 1, k=-40db/dec d 计算相角裕度 =1 有=3.81v cc 1 15 22 c 所以=180-90-arctan=15 c e 计算幅值裕度 -arctan-90=-180x 有 x=rad/s 所以 h= )( 1 x A num=15; den=1 1 0; sys=tf(num,den); margin(sys) hold on grid 5 hold off 2.3 原系统的原系统的 Nyquist 曲线曲线 A 起点 A（0+）= （0+）=-90 B 终点 A（）=0 （）=-180 MATLAB 程序如下： G=tf(15,1 1 0); nyquist(G); 2.4 原系统的根轨迹原系统的根轨迹 原根轨迹的标准式如下 ) 1( 15 )( ss sG a 实轴上的根轨迹为-1,0 N-M=2;所以有 2 条分支线 b 分离点 分离点坐标 有 d=-0.50 1 11 dd c 渐近线 交点= 2 110 MN 交角= 有 k=0 ,； MN k ) 12( 2 3 , 1 2 ； k 与虚轴的交点 讲（0，j）带入特征方程 有 j+（15- ）=0 =3.87 2 所以交点为（0，3.87） num=15; den=1 1 0; sys=tf(num,den); rlocus(sys) hold on plot(0,0) gtext(0) plot(-1,0) 6 gtext(-1) hold off 三、校正装置设计三、校正装置设计 3.1 校正装置参数的确定校正装置参数的确定 = - 原+ (512)这里取 6=45-15+6=36 有 a=（1+sin）/（1-sin）=3.9087 根据 L（c）+10lg(a)=0 有 c=5.4 根据公式 c=m=得出 T=0.0937 aT 1 有 aGc(s)= 1 1 Ts aTs 10937 . 0 1366 . 0 s s 为了补偿无源超前网络产生的增益衰减，放大器的增益要提高 a 倍，否则不可以保证 稳态误差要求。所以校正后的系统传递函数为 G（s）= sss s )1)(10937.0( )1366.0(15 相角裕度 y =180-90+arctan0.366c-arctan0.0937c-arctanc 将 wc=5.4 带入得出 y=46.8 题目要求的是45所以符合条件！ 所以 aGc(s)= a=3.9087 T=0.0937 1 1 Ts aTs 10937 . 0 1366 . 0 s s 3.2 校正装置的校正装置的 Bode 图图 num=0.373 1; den=0.0937 1; sys=tf(num,den); bode(sys) grid 7 四、校正后系统的分析四、校正后系统的分析 4.1 校正后系统的单位阶跃响应曲线校正后系统的单位阶跃响应曲线 单位反馈系统的开环传递函数为 G（s）=，所以单位反馈系统的 sss s ) 1)(10937 . 0 ( ) 1366 . 0 (20 (S)=C(S)/R(S),R(S)=1/S,所以 C（S）= ,经过拉斯反变换得 ) 1)(10937 . 0 ( ) 1366 . 0 (20 2 sss s 到 C（t）的图像即为图六 num=15; den=1 1 0; sys1=tf(num,den); num1=0.366 1; den1=0.0937 1; sys2=tf(num1,den1); sys3=sys1*sys2; sys4=feedback(sys3 ,1); t=0:0.1:6; step(sys4,t) 4.2 校正后系统的校正后系统的 Bode 图图 a 确定各交接频率 w 及斜率变化值 最小相位惯性环节：1=1， 斜率减小 20db/dec; 最小相位惯性环节：2=1/0.0937=10.67 斜率减小 20db/dec; 最小相位一阶微分环节：3=1/0.366=2.73 斜率增加 20db/dec； 最小交接频率：1=1 b 绘制频段（WWmin）渐进特性曲线。 有 20（20/）讲 =0.1 带入，得知过点（0.1,20200），斜率为-20de/dec. C 绘制频段(WWmin)渐进特性曲线 0.11, k=-20db/dec 12.73, k=-40db/dec 2.73w10.47 k=-20db/dec 10.47 k=-40db/dec d 计算相角裕度 8 =1 有 c=5.4；所以 y=180-90-arctanc- 1)0937.0(1 1)366.0(20 222 2 ccc c arctan0.0937c+arctan -arctan0.0693c=45.8c366.0 e 计算幅值裕度 arctan0.366x-arctan0.0937x-arctanx-90=-180 有 x=1000rad/s 所以 h=12800546.45 )( 1 x A MATLAB 程序如下 num=15; den=1 1 0; sys1=tf(num,den); num1=0.366 1; den1=0.0937 1; sys2=tf(num1,den1); sys3=sys1*sys2; margin(sys3) grid 4.3 校正后系统的校正后系统的 Nyquist 曲线曲线 A 起点 A（0+）= （0+）=-90 B 终点 A（）=0 （）=-180 MATLAB 程序如下： num=15; den=1 1 0; sys1=tf(num,den); num1=0.373 1; den1=0.0937 1; sys2=tf(num1,den1); sys3=sys1*sys2; nyquist(sys3) hold on 9 plot(-1,0,o) gtext(-1) hold off 4.4 校正后系统的根轨迹校正后系统的根轨迹 原根轨迹的标准式如下 )67.10)(1( )73 . 2 ( 2 . 78 sss s a 实轴上的根轨迹为（-, -10.67 ;-1,0; N-M=2;所以有 2 条分支线 b 分离点 分离点坐标 有 d=-0.55 73 . 2 1 67.10 1 1 11 dddd c 渐近线 交点= 47 . 4 )73 . 2 ()67.10() 1(0 MN 交角= 有 k=0 , MN k ) 12( ； ； 2 3 , 1 2 k 与虚轴的交点 讲（0，j）带入特征方程 所以交点为（0，4.28） （0，-4.28） 所以根轨迹如图九所示 MATLAB 程序如下： num=15; den=1 1 0; sys1=tf(num,den); num1=0.373 1; den1=0.0937 1; sys2=tf(num1,den1); sys3=sys1*sys2; rlocus(sys3) 10 五、总结五、总结 这次的自动控制系统课程设计微机课设要复杂得多,难得多,同时也让我深深的 体会到自己有很多不足，感觉到上课时其中有很多东西都不是太明白,才发现我们 的理论知识真有些薄弱.当自己看书还有在同学的帮忙下后才真正掌握了一些上课 学到但是学的不扎实的知识。 加之，我也学到了 MATLAB 软件的使用方法，刚开始使用这个软件时真有点不 知所措，连图都画不出来，后来通过学习终于可以顺畅的使用其画图，这让我明 白了做任何都要用心，仔细才能做好，这不仅是一次小小的课设,也是我人生过程 中的一次历练,一次心理战.它让我使自己所学的知识得到了进一步巩固;也让我们的 动手能力和独立思考及发现问题关键的能力得到了进一步提高;更让我明白了自己 心里上的缺欠,容易紧张.做完课设我对自己说:“以后不管发生什么事,我都不会轻言 放弃.“ 六、参考文献六、参考文献 自动控制原理 第五版 科学出版社 11 七、附图七、附图 图一原系统的单位阶跃响应曲线 图二原系统的 Bode 图 12 图三 原系统的 Nyquist 曲线 图四 原系统的根轨迹 13 图五 校正装置的 Bode 图 图六 校正后系统的单位阶跃响应曲线 14 图七 校正后系统的 Bode 图 图八 矫正后的 Nyquist 曲线 15 图九 矫正后的根轨迹 16 您好，为你提供优秀的毕业论文参考资料，请您删除以下内容，您好，为你提供优秀的毕业论文参考资料，请您删除以下内容，O(_)O 谢谢！谢谢！A large group of tea merchants on camels and horses from Northwest Chinas Shaanxi province pass through a stop on the ancient Silk Road, Gansus Zhangye city during their journey to Kazakhstan, May 5, 2015. The caravan, consisting of more than 100 camels, three horse-drawn carriages and four support vehicles, started the trip from Jingyang county in Shaanxi on Sept 19, 2014. It will pass through Gansu province and Xinjiang Uygur autonomous region, and finally arrive in Almaty, formerly known as Alma-Ata, the largest city in Kazakhstan, and Dungan in Zhambyl province. The trip will cover about 15,000 kilometers and take the caravan more than one year to complete. The caravan is expected to return to Jingyang in March 2016. Then they will come back, carrying specialty products from Kazakhstan A small art troupe founded six decades ago has grown into a household name in the Inner Mongolia autonomous region. In the 1950s, Ulan Muqir Art Troupe was created by nine young musicians, who toured remote villages on horses and performed traditional Mongolian music and dances for nomadic families. The 54-year-old was born in Tongliao, in eastern Inner Mongolia and joined the troupe in 1975.He says there are 74 branch troupes across Inner Mongolia and actors give around 100 shows every year to local nomadic people. “I can still recall the days when I toured with the troupe in the early 80s. We sat on the back of pickup trucks for hours. The sky was blue, and we couldnt help but sing the folk songs,“ Nasun says. The vastness of Inner Mongolia and the lack of entertainment options for people living there, made their lives lonely. “The nomadic people were very excited about our visits,“ Nasun recalls. “We didnt have a formal stage. The audience just sat on the grass. Usually, the performances became a big party with local people joining in.“ For him, the rewarding part about touring isnt just about sharing art with nomadic families but also about gaining inspiration for the music and dance. Ulan Muqir literally translates as “red burgeon“, and todays performers of the troupe still tour the regions villages and entertain nomadic families, but their fame has spread around the world. On May 16 and 17, nearly 100 singers and dancers from the troupe performed at Beijings Poly Theater. Their show, titled Ulan Muqir on the Grassland, depicted the history and development of the art troupe. “Being from the region allowed me to embrace the culture of Inner Mongolia and being a member of the troupe showed me where I belonged,“ Nasun, the art troupes president, who is also a renowned tenor, tells China Daily. During a tour in 1985, he went to a village and met an elderly local man, who told him a story about his friendship with a solider from Shenyang, capital of Northeast Chinas Liaoning province, decades ago. The solider gave the old man a handmade saddle when they bid farewell. The story inspired Nasun to write Carved Saddle, a song that later became one of his most popular numbers. Now, every year, Nasun recruits young singers and dancers for the troupe. The troupe has also designed a new repertoire, which is mostly based on the daily lives of Mongolian people, especially the lives of nomadic families, and has combined contemporary musical elements with folk songs of the region. Haimu, a 25-year-old khoomei (a local variant of overtone singing) singer, joined the troupe three years ago. Along with a six- member band, he performs fast songs and soft ones that he writesall while playing the horse-head fiddle.“Although I learned the piano since childhood and grew up listening to various kinds of music, to me, the folk music of Inner Mongolia is the root,“ he says. “Performing in remote villages is pleasant. I feel at home on the b oundless grasslands, and the warm people there make me feel fulfilled.“ The first round of spring auction season in Beijing ended last week, but it failed to create much spring in the art market. Although two pieces of Chinese painting fetched more than 100 million yuan, the decline in trading volume and sale rate showed a downturn this year. In the “Grand View: Chinese Painting Highlight” session at China Guardian 2015 spring auctions, Pan Tianshous representative work Eagle, Rock and Flora hit a record auction price of 279 million yuan, while Li Kerans masterwork Jinggang Mountain fetched 126.5 million yuan, an unexpected high in recent years. However, the trading volume fells to 1.87 billion yuan from 2.22 billion yuan in the same period the year before. The Huangchen 2015 Spring Auctions, which recorded 42.5 million yuan in total sales, experienced the same. The section number went down to 5 from 12 compared to last year. According to expert Shao Jianwu, the art market did not attract much excitement this year due to the booming stock market and the persistent problems of forgery and fake deals. The two pieces of Chinese painting notched up high price this spring due to their own value not due to a revival in the market. “The successful transaction of two works with a hammer price of more than 100 million yuan once again confirms that valuable and rare works of high quality always earn the long-lasting high price. Chinese painting and calligraphy is still the pillar of the market. However, the overall sales rate has dropped slightly, which reflects the demand for the ordinary auction goods has weakened,” said the president of China Guardians Hu Yanyan. “Besides, the entry of new buyers also makes certain changes to the direction of purchasing. In a word, the overall market trend is very unpredictable. Although China Guardian 2015 Spring Auctions has achieved remarkable results, it does not mean that the market has walked out of the predicament. We still have to wait for the big economic boom to invigorate the art market.” Even so, the hot pursuit of some special items appeared this spring. A special session of China Guardian Spring Auctions titled “Fine Gilt Bronze Buddhist Images” achieved a great deal with total sales volume of 41.89 million yuan and 92 percent sale rate. The 5th Shamar Rinpoche Statue from 16-17th century of Tibet was sold for 5.06 million yuan. The Beijing Chengxuan Auctions featured almost 2,800 items of coins and stamps in three sessions with good sale rate. The Huachen Auctions also set a special session of photographs under the condition of large-scale decline of auction sessions. There was a palpable dull thud of disappointment that accompanied the return of the imperial entourage of Zhen Huan to her homeland. It followed a couple years of hushed excitement as Chinese fans were fed tidbits about their proud concubine who was supposed to conquer the high ground of the North American market. Zhen Huan is, of course, the title character of The Legend of Zhen Huan, a 2011 television series that swept China off its feet and later took other Asian countries by storm. Two years ago, it was reported that HBO, a premium cable service headquartered in the United States, was going to air it in North America after some modification. Now, a condensed version that provides English subtitles but no dubbing has finally been made available on Netflix for online streaming. This version, highly anticipated as a milestone in Chinas cultural foray overseas, has been widely panned by its home audience. Retitled Empresses in the Palace, the American version has been shortened from its original 76 episodes at 45 minutes each, to six 90-minute episodes. The quick pacing threw off many native viewers, who are accustomed to a 17 more leisurely daytime-soap-style narrative rhythm. (Chinese TV stations would run two or three episodes every day.) I did not finish the full-length version and found the truncated one not difficult to follow. Whats lost, I believe, are the interesting setups and pauses that illuminate the Chinese art of storytelling. Much of the plot is still there. It is the flavor that was sacrificed. The American edition uses the framework of the Empress Dowager in her senior years reminiscing at the beginning and the end of each episode, hinting at whats to come and recapping the key points. This device, not used in the original, is culturally understandable but artistically mediocre. What puzzles me is the two new songs for the opening and end credits. They were written in English, but sung by Chinese with an uncomfortable accent. They were obviously designed to appeal to an English-speaking base, but do not jibe with the Chinese dialogue. Speaking of the dialogue, the English translation, picked apart by some Chinese, is too literal for my taste. I can imagine a typical American hit by a flurry of royal ranks, addresses and greetings, even multiple names and titles for the same person. The first half hour must be a swamp to wade through, very much like my experience of getting through a Tolstoy tome with its endless inflections of names transliterated into lengthy Chinese. I see the choice of verbatim translation as an effort for conveying exotica. It is fairly competent, with no error that I could detect, but fails to rise above words or capture the essence of the language. A cultural product usually crosses over to a foreign territory first by an emphasis on the commonalities. But whether inside or outside China, the temptation to sell it for the differences is just too great. Sure, the sumptuous sets and costumes are a big attraction, but the narrative technique has becomehow shall I put it?a bit anglicized, which is necessary for cultural export. Judging by the responses, this legend, which, contrary to the claim of the English trailer, is totally fictitious, has departed from China but not yet landed on American shores. I am a big fan of Ralph Waldo Emersons essay titled Self-Reliance. If youve not yet read it, I strongly encourage you to do so. In this essay, the venerable Emerson talks about eschewing the trappings of society and finding ones own path. He urges the reader to find rectitude and lead a moral life. He professes that, only by being self reliant, as opposed to relying on the government and being dictated to by society, can one begin leading a decent and purposeful life. He avers that such a life is the only life worth living. I agree with him. This essay was written during a time of social upheaval in America, and it is rather odd that Emerson authored it, as he was a part of the upper crust of society at the time. It just so happened that he looked around him, at the indolence and the wantonness of the people in his circle; he wondered how in the world he came to belong there. Indeed his penning and publishing this essay caused his excommunication from high society and also caused him a lot of legal trouble. The legal trouble came