G UILLAIN-BARRéSYNDROME(GBS)is an uncommon disorder,but one whose impact is far out of proportion to its incidence.Despite a usually good prognosis,GBS is a particularly frightening and often life- altering experience for those diagnosed with the disorder.Many patients are acutely aware of the rapid loss of control of their muscular function, including vital functions such as breathing and swallowing,and fre- quently feel that they are dying.The experience is almost as unnerving for the families of affected individuals.During the acute phase of the ill- ness GBS patients experience the indignity of helplessness in addition to their fear of death or permanent disability.Prolonged disability is com- mon and some permanent residual effects are becoming increasingly recognized.It has been our experience in meeting patients at support groups,that individuals who have been affected by GBS have a great desire for a better understanding of the disorder,even years after the acute experience.
標簽: UILLAIN-BARR proportion SYNDROME disorder
上傳時間: 2017-07-11
上傳用戶:cuibaigao
設計了一種基于PIC16C71單片機的數字水溫配制閥。該配制閥采用NTC熱敏電阻作溫度傳感器,與固定電阻組成簡單分壓電路作為水溫測量電路,利用PIC16C71單片機內置的8位A/D轉換器把熱敏電阻上的模擬電壓轉換為數字量,PIC16C71單片機控制直流電機驅動混水閥調節冷熱水的混合比例實現水溫調節。給出了控制電路圖,對水溫測量電路的參數選擇和測溫精度作了詳細討論。實驗和分析表明,選用阻值較大的NTC熱敏電阻和分壓電阻可較好地解決熱敏電阻因功耗較大造成的熱擊穿問題。 Abstract: A digital valve for controlling water temperature based on PIC16C71 was presented in this paper.A bleeder circuit which consisted of a NTC thermistor as temperature sensor and a fixed resistance was designed as water temperature measuring circuit.The analog voltage on the thermistor was converted into digital signal by a 8-bit A/D converter embedded in PIC16C71. Based on the digital signal, the MCU PIC16C71 drived the valve by a DC motor to adjust the water temperature through adjusting the proportion of hot water and cold water.The circuit diagram of controller was given,the principle,the component parameters and the accuracy of measuring temperatures were also dissertated in detail. It was found by experiment and analysis that thermal breakdown of thermistor caused by high power could be solved by selecting thermistor and fixed resistance with high impedance value.
上傳時間: 2013-11-08
上傳用戶:Yue Zhong
對于PID初學者頗有指導,將偏差的比例(proportion)、積分(Integral)和微分(Differential)通過線性組合構成控制量, 用這一控制量對被控對象進行控制,這樣的控制器稱 PID 控制器。
標簽: PID
上傳時間: 2016-04-27
上傳用戶:547453159
pid控制 #ifndef _PID_H #ifndef _PID_H #ifdef _PID_C #define PID_EXT #else #define PID_EXT extern #endif typedef struct PID { int SetPoint; unsigned char BitMove; float proportion; float Integral; float Derivative; int iError; int iIncpid; int LastError; int PrevError; int Uk; }PID,*pPID; PID_EXT PID sPID; PID_EXT pPID sptr; void IncPIDInit(void); int IncPIDCalc(int NextPoint); #endif
上傳時間: 2019-08-02
上傳用戶:stcwzy
The family of recent wireless standards included the optional employment of Multiple-Input Multiple-Output(MIMO)techniques.This was motivatedby the observationaccordingto the classic Shannon–Hartley law that the achievable channel capacity increases logarithmically with the transmit power. In contrast, the MIMO capacity increases linearly with the number of transmit antennas, provided that the number of receive antennas is equal to the number of transmit antennas. With the further proviso that the total transmit power is increased in proportion to the number of transmit antennas, a linear capacity increase is achieved upon increasing the transmit power, which justifies the spectacular success of MIMO systems.
標簽: Multi-Functional Systems MIMO
上傳時間: 2020-05-31
上傳用戶:shancjb
首先介紹一下原理,其實很簡單,磁力對懸浮物的控制,其基本原理是:霍爾傳感器在浮子的正下方,當檢測到浮子向左運動時,兩邊的線圈一個吸一個拉,把它推向右;反之如果浮子想右運動,那么兩個線圈的電流都反向,總共兩組共四個這樣的線圈,就可以把浮子限制在二維平面之內了。但是線圈產生的力是比較小的,因此只能夠推動浮子在水平面移動,要克服浮子的重力讓它懸浮起來,就要在四個線圈下面再加一個大的環形磁鐵提供斥力。為了讓懸浮更加穩定,我們采用了PID控制的平衡算法,對PID算法的了解有助于我們對整個實驗原理的理解,借用網上對PID的一段介紹:在工程實際中,PID控制是應用最為廣泛的調節器控制機制。PID控制中得P代表比例,即proportion;I代表積分,即integral;D代表微分,即differential;因此,PID控制,即比例-積分-微分控制。當被控對象的結構和參數不能完全掌握,或者得不到精確的數學模型時,其他的控制方法難以采用,那么控制器的結構和參數必須結合經驗和現場調試來決定,在這種情況下采用PID調節最為方便。首先,比例控制是一種最簡單的控制方式,就像胡克公式中的比例系數一樣,當控制器的輸出與輸入信號成比例關系,那么就可以得到一個比例系數。其次,積分控制是指控制器的輸出與輸入的誤差信號的積分有關。就如同電路中的電感元件,某個時刻的電壓與電流的積分有關。類似的,有時候信號的輸出必須綜合之前信號的輸入,而這種綜合往往是求和關系,因此使用積分控制簡單易行。最后,微分控制是指控制器的輸出與輸入信號的微分有關。最簡單的微分關系就是速度是位矢的微分。我們在控制懸浮物的平衡時,光知道懸浮物偏離平衡位置的位移從而采用比例控制是不夠的,對于同樣的偏離位移,懸浮物可能有不同的速度,那么要求我們對懸浮物有不同的處理方法,而恰恰速度是位矢的微分,于是我們可以通過對位移輸入數據進行微分操作,來實現對懸浮物的精確實時控制。可見,PID控制器是一種那個動態的控制機制。 以上就是實現下推式磁懸浮的基本原理,借助以上的基本原理,結合一定的軟件算法實現,我們就可以對懸浮物進行動態控制。
上傳時間: 2022-06-07
上傳用戶:canderile
#nclude<reg51.h>#include<intrins.h>#銷nclude<math.h>#include<string.h>struct PID{unsigned int SetPoint;//設定目標 Desired Value unsigned int proportion;//比例常數proportional Const unsigned int integral;//積分常數Integral Const unsigned int Derivative://微分常數Derivative Const unsigned int LastError;//Emorl-1]unsigned int PrevError;//Errorl-2]unsigned int SumError;//Sums of Errors struct PID spid;//PID Control Structure unsigned int rout;//PID Response(Output)unsigned int rin://PID Feedback(Input)sbit data1=P100;sbit clk=P141;sbit plus=P240;sbit subs=P241:sbit stop=P22;sbit output=P34;sbit DQ=P33;unsigned char flag,flag_1=0;unsigned char high_time,low_time,.count=0,/占空比調節參數unsigned char set_temper=35;unsigned char temper;unsigned chari:unsigned charj=0;unsigned ints;
上傳時間: 2022-07-02
上傳用戶:xsr1983
將偏差的比例(proportion)、積分(Integral)和微分(Differential)通過線性組合構成控制量,用這一控制量對被控對象進行控制,這樣的控制器稱PID控制器。1.1模擬PID控制原理在模擬控制系統中,控制器最常用的控制規律是PID控制。為了說明控制器的工作原理,先看一個例子。如圖1-1所示是一個小功率直流電機的調速原理圖。給定速度n(f)與實際轉速進行比較n(),其差值e()=n(0-n(),經過PID控制器調整后輸出電壓控制信號u),u)經過功率放大后,驅動直流電動機改變其轉速。常規的模擬PID控制系統原理框圖如圖1-2所示。該系統由模擬PID控制器和被控對象組成。圖中,r()是給定值,y(f)是系統的實際輸出值,給定值與實際輸出值構成控制偏差e(t)e()作為PID控制的輸入,以)作為PID控制器的輸出和被控對象的輸入。所以模擬PID控制器的控制規律為
標簽: pid控制
上傳時間: 2022-07-04
上傳用戶: