C51单片机设计的水箱温度PID控制系统的程序

此系统是基于PID的单片机温度控制系统，我在网上搜到一段完整的程序，并按他的程序做出了相应的proteus硬件仿真，但是并没有达到预期的效果.待提高。

程序如下：

#include＜reg51.h> #include＜intrins.h> #include＜math.h> #include＜string.h> struct PID { unsigned int SetPoint; // 设定目标 Desired Value unsigned int Proportion; // 比例常数 Proportional Const unsigned int Integral; // 积分常数 Integral Const unsigned int Derivative; // 微分常数 Derivative Const unsigned int LastError; // Error[-1] unsigned int PrevError; // Error[-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=P1^0; sbit clk=P1^1; sbit plus=P2^0; sbit subs=P2^1; sbit stop=P2^2; sbit output=P3^4; sbit DQ=P3^3; unsigned char flag,flag_1=0; unsigned char high_time,low_time,count=0;//占空比调节参数 unsigned char set_temper=35; unsigned char temper; unsigned char i; unsigned char j=0; unsigned int s; /*********************************************************** 延时子程序,延时时间以12M晶振为准,延时时间为30us×time ***********************************************************/ void delay(unsigned char time) { unsigned char m,n; for(n=0;n＜time;n++) for(m=0;m＜2;m++){} } /*********************************************************** 写一位数据子程序 ***********************************************************/ void write_bit(unsigned char bitval) { EA=0; DQ=0; /*拉低DQ以开始一个写时序*/ if(bitval==1) {   _nop_();   DQ=1; /*如要写1，则将总线置高*/ } delay(5); /*延时90us供DA18B20采样*/ DQ=1; /*释放DQ总线*/ _nop_(); _nop_(); EA=1; } /*********************************************************** 写一字节数据子程序 ***********************************************************/ void write_byte(unsigned char val) { unsigned char i; unsigned char temp; EA=0; TR0=0; for(i=0;i＜8;i++) /*写一字节数据，一次写一位*/ {   temp=val>>i; /*移位操作，将本次要写的位移到最低位*/   temp=temp&1;   write_bit(temp); /*向总线写该位*/ } delay(7); /*延时120us后*/ // TR0=1; EA=1; } /*********************************************************** 读一位数据子程序 ***********************************************************/ unsigned char read_bit() { unsigned char i,value_bit; EA=0; DQ=0; /*拉低DQ，开始读时序*/ _nop_(); _nop_(); DQ=1; /*释放总线*/ for(i=0;i＜2;i++){} value_bit=DQ; EA=1; return(value_bit); } /*********************************************************** 读一字节数据子程序 ***********************************************************/ unsigned char read_byte() { unsigned char i,value=0; EA=0; for(i=0;i＜8;i++) {   if(read_bit()) /*读一字节数据，一个时序中读一次，并作移位处理*/   value|=0x01＜＜i;   delay(4); /*延时80us以完成此次都时序，之后再读下一数据*/ } EA=1; return(value); } /*********************************************************** 复位子程序 ***********************************************************/ unsigned char reset() { unsigned char presence; EA=0; DQ=0; /*拉低DQ总线开始复位*/ delay(30); /*保持低电平480us*/ DQ=1; /*释放总线*/ delay(3); presence=DQ; /*获取应答信号*/ delay(28); /*延时以完成整个时序*/ EA=1; return(presence); /*返回应答信号，有芯片应答返回0,无芯片则返回1*/ } /*********************************************************** 获取温度子程序 ***********************************************************/ void get_temper() { unsigned char i,j; do {   i=reset(); /*复位*/ }while(i!=0); /*1为无反馈信号*/ i=0xcc; /*发送设备定位命令*/ write_byte(i); i=0x44; /*发送开始转换命令*/ write_byte(i); delay(180); /*延时*/ do {   i=reset(); /*复位*/ }while(i!=0); i=0xcc; /*设备定位*/ write_byte(i); i=0xbe; /*读出缓冲区内容*/ write_byte(i); j=read_byte(); i=read_byte(); i=(i＜＜4)&0x7f; s=(unsigned int)(j&0x0f); s=(s*100)/16; j=j>>4; temper=i|j; /*获取的温度放在temper中*/ } /*==================================================================================================== Initialize PID Structure =====================================================================================================*/ void PIDInit (struct PID *pp) { memset ( pp,0,sizeof(struct PID)); } /*==================================================================================================== PID计算部分 =====================================================================================================*/ unsigned int PIDCalc( struct PID *pp, unsigned int NextPoint ) { unsigned int dError,Error; Error = pp->SetPoint - NextPoint; // 偏差 pp->SumError += Error; // 积分 dError = pp->LastError - pp->PrevError; // 当前微分 pp->PrevError = pp->LastError; pp->LastError = Error; return (pp->Proportion * Error // 比例项 + pp->Integral * pp->SumError // 积分项 + pp->Derivative * dError); // 微分项 } /*********************************************************** 温度比较处理子程序 ***********************************************************/ compare_temper() { unsigned char i; if(set_temper>temper) {   if(set_temper-temper>1)   {    high_time=100;    low_time=0;   }   else   {    for(i=0;i＜10;i++)    {     get_temper();     rin = s; // Read Input     rout = PIDCalc ( &spid,rin ); // Perform PID Interation    }    if (high_time＜=100)    {    high_time=(unsigned char)(rout/800);    }   else    {    high_time=100;      }   low_time= (100-high_time);   } } else if(set_temper＜=temper) {   if(temper-set_temper>0)   {    high_time=0;    low_time=100;   }   else   {    for(i=0;i＜10;i++)    {     get_temper();     rin = s; // Read Input     rout = PIDCalc ( &spid,rin ); // Perform PID Interation    }    if (high_time＜100)    {    high_time=(unsigned char)(rout/10000);    }   else    {    high_time=0;    }   low_time= (100-high_time);   } } // else // {} } /***************************************************** T0中断服务子程序，用于控制电平的翻转 ,40us*100=4ms周期 ******************************************************/ void serve_T0() interrupt 1 using 1 { if(++count＜=(high_time)) output=1; else if(count＜=100) {   output=0; } else count=0; TH0=0x2f; TL0=0xe0; } /***************************************************** 串行口中断服务程序，用于上位机通讯 ******************************************************/ void serve_sio() interrupt 4 using 2 { /* EA=0; RI=0; i=SBUF; if(i==2) { while(RI==0){} RI=0; set_temper=SBUF; SBUF=0x02; while(TI==0){} TI=0; } else if(i==3) { TI=0; SBUF=temper; while(TI==0){} TI=0; } EA=1; */ } void disp_1(unsigned char disp_num1[6]) { unsigned char n,a,m; for(n=0;n＜6;n++) { // k=disp_num1[n];   for(a=0;a＜8;a++)   {    clk=0;    m=(disp_num1[n]&1);    disp_num1[n]=disp_num1[n]>>1;    if(m==1)    data1=1;    else    data1=0;    _nop_();    clk=1;    _nop_();   } } } /***************************************************** 显示子程序 功能：将占空比温度转化为单个字符，显示占空比和测得到的温度 ******************************************************/ void display() { unsigned char code number[]={0xfc,0x60,0xda,0xf2,0x66,0xb6,0xbe,0xe0,0xfe,0xf6}; unsigned char disp_num[6]; unsigned int k,k1; k=high_time; k=k%1000; k1=k/100; if(k1==0) disp_num[0]=0; else disp_num[0]=0x60; k=k%100; disp_num[1]=number[k/10]; disp_num[2]=number[k%10]; k=temper; k=k%100; disp_num[3]=number[k/10]; disp_num[4]=number[k%10]+1; disp_num[5]=number[s/10]; disp_1(disp_num); } /*********************************************************** 主程序 ***********************************************************/ main() { unsigned char z; unsigned char a,b,flag_2=1,count1=0; unsigned char phil[]={2,0xce,0x6e,0x60,0x1c,2};; TMOD=0x21; TH0=0x2f; TL0=0x40; SCON=0x50; PCON=0x00; TH1=0xfd; TL1=0xfd; PS=1; EA=1; EX1=0; ET0=1; ES=1; TR0=1; TR1=1; high_time=50; low_time=50; PIDInit ( &spid ); // Initialize Structure spid.Proportion = 10; // Set PID Coefficients spid.Integral = 8; spid.Derivative =6; spid.SetPoint = 100; // Set PID Setpoint while(1) {   if(plus==0)   {    EA=0;    for(a=0;a＜5;a++)     for(b=0;b＜102;b++){}    if(plus==0)    {     set_temper++;     flag=0;    }   }   else if(subs==0)   {    for(a=0;a＜5;a++)     for(b=0;a＜102;b++){}    if(subs==0)    {     set_temper--;     flag=0;    }   }   else if(stop==0)   {    for(a=0;a＜5;a++)     for(b=0;b＜102;b++){}    if(stop==0)    {     flag=0;     break;    }    EA=1;   }   get_temper();   b=temper;   if(flag_2==1)   {   a=b;  }   if((abs(a-b))>5)   {   temper=a;  }   else   {     temper=b;  }   a=temper;   flag_2=0;   if(++count1>30)   {    display();    count1=0;   }   compare_temper(); } TR0=0; z=1; while(1) {   EA=0;   if(stop==0)   {    for(a=0;a＜5;a++)     for(b=0;b＜102;b++){}    if(stop==0)    disp_1(phil);    // break;   }   EA=1; } }