Mercurial > mbsePi-apps / file comparison
comparison: brewco/pid.c
brewco/pid.c
- changeset 434
- eb724767860d
- child 435
- 4b1ed6897d80
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| 433:1421ece29197 | 434:eb724767860d |
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| 1 /***************************************************************************** | |
| 2 * Copyright (C) 2015 | |
| 3 * | |
| 4 * Michiel Broek <mbroek at mbse dot eu> | |
| 5 * | |
| 6 * This file is part of the mbsePi-apps | |
| 7 * | |
| 8 * This is free software; you can redistribute it and/or modify it | |
| 9 * under the terms of the GNU General Public License as published by the | |
| 10 * Free Software Foundation; either version 2, or (at your option) any | |
| 11 * later version. | |
| 12 * | |
| 13 * mbsePi-apps is distributed in the hope that it will be useful, but | |
| 14 * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 16 * General Public License for more details. | |
| 17 * | |
| 18 * You should have received a copy of the GNU General Public License | |
| 19 * along with ThermFerm; see the file COPYING. If not, write to the Free | |
| 20 * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
| 21 *****************************************************************************/ | |
| 22 | |
| 23 #include "brewco.h" | |
| 24 #include "pid.h" | |
| 25 | |
| 26 | |
| 27 void InitPID(pid_var *pid) | |
| 28 { | |
| 29 pid->Err = pid->ErrLast = pid->iState = 0.0; | |
| 30 pid->Input = pid->OutP = pid->SetP = 0.0; | |
| 31 pid->pGain = pid->iGain = pid->dGain = 0.0; | |
| 32 pid->Mode = PID_MODE_NONE; | |
| 33 pid->iMax = 100.0; | |
| 34 } | |
| 35 | |
| 36 | |
| 37 | |
| 38 void UpdatePID(pid_var *pid) | |
| 39 { | |
| 40 if (pid->Mode == PID_MODE_AUTO) { | |
| 41 | |
| 42 double pTerm, dTerm, iTerm; | |
| 43 | |
| 44 pid->Err = pid->SetP - pid->Input; | |
| 45 | |
| 46 /* | |
| 47 * Calculate the integral state with appopriate limiting. | |
| 48 * Use ErrLastLast as iState | |
| 49 */ | |
| 50 pid->iState += pid->Err; | |
| 51 if (pid->iState > PID_WINDUP_GUARD) | |
| 52 pid->iState = PID_WINDUP_GUARD; | |
| 53 else if (pid->iState < -PID_WINDUP_GUARD) | |
| 54 pid->iState = -PID_WINDUP_GUARD; | |
| 55 | |
| 56 pTerm = pid->pGain * pid->Err; | |
| 57 iTerm = pid->iGain * pid->iState; | |
| 58 dTerm = pid->dGain * (pid->Err - pid->ErrLast); | |
| 59 | |
| 60 pid->OutP = pTerm + dTerm + iTerm; | |
| 61 pid->ErrLast = pid->Err; | |
| 62 | |
| 63 } else if (pid->Mode == PID_MODE_BOO) { | |
| 64 /* | |
| 65 * Mode Bang On Off | |
| 66 */ | |
| 67 pid->ErrLast = pid->Err; | |
| 68 pid->Err = pid->SetP - pid->Input; | |
| 69 | |
| 70 if (pid->OutP && (pid->Err <= 0.0)) | |
| 71 pid->OutP = 0.0; | |
| 72 else if ((pid->OutP == 0.0) && (pid->Err > 0.0)) | |
| 73 pid->OutP = pid->iMax; | |
| 74 | |
| 75 pid->iState = 0.0; | |
| 76 | |
| 77 } else { | |
| 78 /* | |
| 79 * While in manual mode, stay ready for bumpless switch to | |
| 80 * auto. | |
| 81 */ | |
| 82 pid->ErrLast = pid->Err = 0.0; | |
| 83 pid->OutP = pid->iState = 0.0; | |
| 84 } | |
| 85 | |
| 86 if (pid->OutP > pid->iMax) | |
| 87 pid->OutP = pid->iMax; | |
| 88 if (pid->OutP < 0.0) | |
| 89 pid->OutP = 0.0; | |
| 90 | |
| 91 } | |
| 92 | |
| 93 |
