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北科大自动控制理论课程设计

题目:天线接收卫星信号的PID研究摘要PID控制器是目前工业过程控制中,应用最广泛的工业控制器之一。

本篇文章以大型天线接收卫星信号,跟踪卫星运动系统为基础构造数学模型,设计PID控制器进行控制并进行MA TLAB仿真。

ABSTRACT PID controller is the industrial process control, one of the most widely used industrial controller. This article to the large antenna for receiving satellite signal, tracking satellite motion system based on structure mathematical model, design of PID controller and MA TLAB simulation关键词关键词一:卫星信号; 关键词二:准确定向; 关键词三:PID控制器; 关键词四:matlab仿真; 关键词五引言:当今的自动控制技术都是基于反馈的概念。

反馈理论的要素包括三个部分:测量、比较和执行。

测量关心的变量,与期望值相比较,用这个误差纠正调节控制系统的响应。

PID控制器由比例单元(P)、积分单元(I)和微分单元(D)组成。

其输入e (t)与输出u (t)的关系为:u(t)=kp[e(t)+1/TI∫e(t)dt+TD*de(t)/dt] 式中积分的上下限分别是0和t,因此它的传递函数为:G(s)=U(s)/E(s)=kp[1+1/(TI*s)+TD*s],其中kp为比例系数;TI为积分时间常数;TD为微分时间常数INTRODUCTION:The automatic control technology is based on the notion of feedback. Feedback theory consists of three parts: measurement, comparison and implementation. Measurement of variables of interest, and expected value are compared, with the error correction control system response. PID controller by proportional unit (P ), integral unit ( I ) and differential unit ( D ). The input and output e ( T ) U ( T ) relationship is: u (T) =kp[e ( T ) +1/TI∫ e ( T ) dt+TD*de ( T ) /dt] type integral limits were 0 and T, so its transfer function : G ( s ) =U ( /E ( s ) s ) =kp[1+1/ ( TI*s ) +TD*s], where KP is proportional coefficient; TI integral time constant; TD differential time constant大型天线可以接收卫星信号,为了能跟踪卫星的运动,必须保证天线的准确定向。

天线指向控制系统采用电枢控制的电机驱动天线,讨论PID控制器的设计,以达到对系统的更高的品质要求。

R(s)1.1 原系统模型参数:没加PID调节器时的反馈系统:单位阶跃曲线:系统很不稳定Bode图:Matlab函数:>> g=tf([10],[1 15 50 10])Transfer function: 10 ------------------------ s^3 + 15 s^2 + 50 s + 10 >> margin(g)-150-100-50M a g n i t u d e (d B )101010101010-270-180-90P h a s e (d e g )Bode DiagramGm = 37.4 dB (at 7.07 rad/sec) , P m = -180 deg (at 0 rad/sec)Frequency (rad/sec)幅值裕度:37.4db 穿越频率:7.07rad/sec 相角裕度:-180 截止频率:0零极点分布图:P ole-Zero MapReal AxisI m a g i n a r y A x i s根轨迹:-40-30-20-1001020-30-20-10102030Root LocusReal AxisI m a g i n a r y A x i s在虚轴右侧有根轨迹图形,系统不稳定,需添加PID 调节1.2添加PID 调节参数:传递函数Gc(s)=Kp+Kds= KpPID参数整定:使系统由Ⅰ型系统转化为Ⅱ型系统增加开环零点使极点尽量靠近虚轴根据公式计算控制器参数。

0.50.125GAIN=10Gain=30Gain=60Gain=75调出了等幅震荡则取Km=75,整合出PID三个值结合原系统参数整定得PID参数得:则添加PID后的开环函数为:闭环函数为:则Kp=10.01 Ki=0.1 Kd=1 Simulink仿真界面:.阶跃响应:可以看出,系统稳定了许多整定后的Bode 图:M a g n i t u d e (d B )10-310-210-110101102P h a s e (d e g )Bode DiagramGm = Inf dB (at Inf rad/sec) , P m = 167 deg (at 0.439 rad/sec)Frequency (rad/sec)幅值裕度:无穷大 穿越频率:无穷大 相角裕度:167截止频率:0.439rad/sec整定前后bode 图对比:(蓝色:整定前。

绿色:整定后)Matlab 函数:>> s=tf([10 0.1],[1 5 10 0.1])Transfer function: 10 s + 0.1 ------------------------ s^3 + 5 s^2 + 10 s + 0.1>> margin(s) >> hold on >> margin(g) >> grid on-150-100-5050M a g n i t u d e (d B )10-310-210-110101102103-270-180-90P h a s e (d e g )Bode DiagramGm = 37.4 dB (at 7.07 rad/sec) , P m = -180 deg (at 0 rad/sec)Frequency (rad/sec)根轨迹图:-6-5-4-3-2-101-1.5-1-0.50.511.5Root LocusReal Axis I m a g i n a r y A x i s可以看出:零极点全到了虚轴的左侧,系统稳定2.1 有改良的PID :(添加一前置滤波器)可以看出:系统更加趋于平缓,甚至无震荡,超调量明显减小,很稳定Bode图:绿色:原系统的bode图红色:增加PID调节器的bode图紫色:添加前置滤波器的bode图-200-150-100-50050M a g n i t u d e (d B)10-410-310-210-1100101102103-270-180-900P h a s e (d e g)Bode DiagramGm = 54 dB (at 3.16 rad/sec) , P m = -180 deg (at 0 rad/sec)Frequency (rad/sec)幅值裕度:54db穿越频率:3.16rad/sec相角裕度:-180截止频率:0参 考 文 献[1] Du Z J, Yang K Z, Gu Y Y , et al. Hydrothermal preparation and microstructure analysis of silver tin oxide contact materials. J Univ Sci Technol Beijing , 2007, 29(10): 1023(杜作娟, 杨开足, 古映莹, 等. 银氧化锡触点材料的水热制备及组织分析. 北京科技大学学报, 2007, 29(10): 1023)[2] Araki H, Saji S, Okabe T, et al. Solidation of mechanically alloyed Al -10.7%Ti powder at low temperature and high pressure of 2 GPa. Mater Trans JIM , 1995, 36 (3): 465[3] Wu C J, Chen G L, Qiang W J. Metal Material Science . Beijing: Metallurgical Industry Press, 2000(吴承建,陈国良,强文江. 金属材料学. 北京:冶金工业出版社,2000)[4] Shen C, Shi X L, Tang S G , et al. The application of dynamic control steelmaking with gas analysis in Masteel // Proceedings of China Iron & Steel Annual Meeting . Beijing, 2005: 165(沈昶,施雄梁,汤曙光,等. 烟气分析动态控制炼钢在马钢的应用//中国钢铁年会论文集. 北京,2005:165)[5] Wang L B. A Study on the Bars ’ Cooling Equipment and the Cooling Parameters [Dissertation]. Beijing: University of Science and Technology Beijing, 2009: 2(王令宝. 棒材控冷设备结构及其参数研究[学位论文]. 北京: 北京科技大学,2009:2)[6] Ni W, Zheng Y C, Guo Z N, et al. A Method of Making High Strength Structural Material with Iron Ore Tailing : China Patent, 200710177294. 2008-05-21(倪文,郑永超,郭珍妮, 等. 一种利用铁尾矿制备高强结构材料的方法:中国专利, 200710177294. 2008-05-21)[7] Professional Standard s Compilation Group of People’s Republic of China. SL264-2001 Specifications for Rock Tests in WaterConservancy and Hydroelectricengineering. Beijing: China Water Power Press, 2001(中华人民共和国行业标准编写组.SL264-001水利水电工程岩石实验规程.北京:中国水利水电出版社,2001)注:(1) 所有非英文文献均须同时列出相应的英文.(2)各参考文献均需列出3位作者之后,再加“等”, 页号只要起始页.(3)会议论文集必须标明会议地点,专著必须标明出版地点和出版社.(4) 以上分别列出:期刊、专著、会议论文、学位论文、专利、标准的著录格式.。

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