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基于AVR ATMega16 的PID 控制算法程序

作者: 時(shí)間:2016-11-18 來源:網(wǎng)絡(luò) 收藏
最近由于有些時(shí)間,于是想起了做一個(gè)PID設(shè)計(jì),在網(wǎng)上收集了不少關(guān)于PID控制的理論,于是計(jì)劃用mega16L做一個(gè)PID測(cè)試程序,發(fā)現(xiàn)一些意想不到的誤差,不知各位同仁是否有遇到與我的類似的現(xiàn)象:我定義了一個(gè)PID結(jié)構(gòu)體,在初始化的時(shí)候無法把每個(gè)元素的初始化值設(shè)置為0(見下面的仿真圖),而且,PID結(jié)構(gòu)體中的部分參數(shù)是應(yīng)該不變的,在整個(gè)PID運(yùn)算中,但是不應(yīng)該變化的參數(shù)卻在PID運(yùn)算發(fā)生了變化,不知道是什么原因,到現(xiàn)在也無法查出原因。有興趣的朋友可以一起參與討論或有經(jīng)驗(yàn)的朋友 給與相關(guān)幫助,謝謝!
詳細(xì)的代碼和仿真情況如下:(我的硬件系統(tǒng)是本站的min Mega16/32 + JTAG ICE)
  1. #include "config.h"
  2. struct _PID
  3. {
  4. float PVn; //反饋信號(hào)變量
  5. float SPn; //設(shè)定值
  6. float Mn; //PID運(yùn)算結(jié)果
  7. float Kc; //比例系數(shù)
  8. float Ts; //采樣時(shí)間(ms)
  9. float Ti; //積分時(shí)間(ms)
  10. float Td; //微分時(shí)間(ms)
  11. float Mx; //積分項(xiàng)調(diào)整參數(shù)
  12. float PVn_1;//前一次反饋?zhàn)兞?/li>
  13. float MPn; //比例項(xiàng)的結(jié)果值
  14. float MIn; //積分項(xiàng)的結(jié)果值
  15. float MDn; //微分項(xiàng)的結(jié)果值
  16. };
  17. struct _PID *myPID;
  18. void init_myPID(void);
  19. void init_ports(void);
  20. void init_device(void);
  21. float MPn_value(struct _PID *PID);
  22. float MIn_value(struct _PID *PID);
  23. float MDn_value(struct _PID *PID);
  24. float Mx_value(struct _PID *PID);
  25. float Mn_value(struct _PID *PID);
  26. void main (void)
  27. {
  28. init_device();
  29. init_myPID();
  30. myPID->SPn = 155.5;
  31. myPID->Kc = 13.2;
  32. myPID->Ts = 0.2;
  33. myPID->Ti = 600.0;
  34. myPID->Td = 0.0;
  35. myPID->PVn = 108.2;
  36. while(1)
  37. {
  38. myPID->MPn = MPn_value(myPID);
  39. myPID->MDn = MDn_value(myPID);
  40. myPID->Mx = Mx_value(myPID);
  41. myPID->MIn = MIn_value(myPID);
  42. myPID->Mn = Mn_value(myPID);
  43. myPID->PVn_1 = myPID->PVn;
  44. }
  45. }
  46. /******************************************************************************/
  47. void init_myPID(void)
  48. {
  49. myPID->PVn = 0.0;
  50. myPID->SPn = 0.0;
  51. myPID->Mn = 0.0;
  52. myPID->Kc = 0.0;
  53. myPID->Ts = 0.0;
  54. myPID->Ti = 0.0;
  55. myPID->Td = 0.0;
  56. myPID->Mx = 0.0;
  57. myPID->PVn_1 = 0.0;
  58. myPID->MPn = 0.0;
  59. myPID->MIn = 0.0;
  60. myPID->MDn = 0.0;
  61. }
  62. //------------------------------------------------------------------------------
  63. void init_ports(void)
  64. {
  65. PORTA = 0x00; //If ADC Function was be used,the PORTA could`t set bit 1
  66. DDRA = 0x00; //the port set input mode.
  67. PORTB = 0x00;
  68. DDRB = 0x00;
  69. PORTC = 0x00; //m103 output only
  70. DDRC = 0x00;
  71. PORTD = 0x00;
  72. DDRD = 0x00;
  73. }
  74. //------------------------------------------------------------------------------
  75. void init_device(void)
  76. {
  77. CLI();
  78. init_ports();
  79. MCUCR = 0x00; //Set Power control(State:Close)
  80. GICR = 0x00; //Set boot guide(State:Close).
  81. SEI(); //re-enable interrupts
  82. //all peripherals are now initialized
  83. }
  84. // 計(jì)算 比例項(xiàng)的值
  85. //------------------------------------------------------------------------------
  86. float MPn_value(struct _PID *PID)
  87. {
  88. float myMPn = 0.0;
  89. myMPn = PID->Kc *( PID->SPn - PID->PVn);
  90. return myMPn;
  91. }
  92. //計(jì)算積分項(xiàng)的值
  93. //------------------------------------------------------------------------------
  94. float MIn_value(struct _PID *PID)
  95. {
  96. float myMIn = 0.0;
  97. myMIn = PID->Kc*(PID->Ts/PID->Ti)*(PID->SPn - PID->PVn) + PID->Mx;
  98. return myMIn;
  99. }
  100. //計(jì)算微分項(xiàng)的值
  101. //------------------------------------------------------------------------------
  102. float MDn_value(struct _PID *PID)
  103. {
  104. float myMDn = 0.0;
  105. myMDn = PID->Kc * (PID->Td/PID->Ts) * (PID->PVn_1 - PID->PVn);
  106. return myMDn;
  107. }
  108. //計(jì)算PID的結(jié)果
  109. //------------------------------------------------------------------------------
  110. float Mn_value(struct _PID *PID)
  111. {
  112. float myMn = 0.0;
  113. myMn = PID->MPn + PID->MIn + PID->MDn;
  114. return myMn;
  115. }
  116. //計(jì)算積分項(xiàng)的調(diào)整值
  117. //------------------------------------------------------------------------------
  118. float Mx_value(struct _PID *PID)
  119. {
  120. float myMx = 0.0;
  121. if(PID->Mn > 1.0)
  122. {
  123. myMx = 1.0 - (PID->MPn + PID->MDn);
  124. }
  125. else if(PID->Mn < 0.0)
  126. {
  127. myMx = -(PID->MPn + PID->MDn);
  128. }
  129. return myMx;
  130. }

本文引用地址:http://m.butianyuan.cn/article/201611/315722.htm

運(yùn)行到PID初始化函數(shù):void init_myPID(void)時(shí)的仿真結(jié)果如下:無法全部初始化為0

運(yùn)行到:
myPID->SPn = 155.5;
myPID->Kc = 13.2;
myPID->Ts = 0.2;
myPID->Ti = 600.0;
myPID->Td = 0.0;
myPID->PVn = 108.2;

重新賦值后,部分參數(shù)Ts并不為0.2



關(guān)鍵詞: AVRATMega16PID控制算

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