Michael Ball / PID

This is a copy of the Reference Standard PID controller ala controlguru.com

Fork of PID by FRDM-K64F Code Share

PID.h@2:55bf0f813bb4, 2016-01-27 (annotated)

Committer:
unix_guru
Date:
Wed Jan 27 21:32:11 2016 +0000
Revision:
2:55bf0f813bb4
Parent:
1:117e0c36eb22
Child:
3:316f974b7f98
minor updates to comply with Brett Beauregard's Arduino PID library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
unix_guru 2:55bf0f813bb4 1 /**
unix_guru 2:55bf0f813bb4 2 * @author Aaron Berk
unix_guru 2:55bf0f813bb4 3 *
unix_guru 2:55bf0f813bb4 4 * @section LICENSE
unix_guru 2:55bf0f813bb4 5 *
unix_guru 2:55bf0f813bb4 6 * Copyright (c) 2010 ARM Limited
unix_guru 2:55bf0f813bb4 7 *
unix_guru 2:55bf0f813bb4 8 * Permission is hereby granted, free of charge, to any person obtaining a copy
unix_guru 2:55bf0f813bb4 9 * of this software and associated documentation files (the "Software"), to deal
unix_guru 2:55bf0f813bb4 10 * in the Software without restriction, including without limitation the rights
unix_guru 2:55bf0f813bb4 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
unix_guru 2:55bf0f813bb4 12 * copies of the Software, and to permit persons to whom the Software is
unix_guru 2:55bf0f813bb4 13 * furnished to do so, subject to the following conditions:
unix_guru 2:55bf0f813bb4 14 *
unix_guru 2:55bf0f813bb4 15 * The above copyright notice and this permission notice shall be included in
unix_guru 2:55bf0f813bb4 16 * all copies or substantial portions of the Software.
unix_guru 2:55bf0f813bb4 17 *
unix_guru 2:55bf0f813bb4 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
unix_guru 2:55bf0f813bb4 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
unix_guru 2:55bf0f813bb4 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
unix_guru 2:55bf0f813bb4 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
unix_guru 2:55bf0f813bb4 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
unix_guru 2:55bf0f813bb4 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
unix_guru 2:55bf0f813bb4 24 * THE SOFTWARE.
unix_guru 2:55bf0f813bb4 25 *
unix_guru 2:55bf0f813bb4 26 * @section DESCRIPTION
unix_guru 2:55bf0f813bb4 27 *
unix_guru 2:55bf0f813bb4 28 * A PID controller is a widely used feedback controller commonly found in
unix_guru 2:55bf0f813bb4 29 * industry.
unix_guru 2:55bf0f813bb4 30 *
unix_guru 2:55bf0f813bb4 31 * This library is a port of Brett Beauregard's Arduino PID library:
unix_guru 2:55bf0f813bb4 32 *
unix_guru 2:55bf0f813bb4 33 * http://www.arduino.cc/playground/Code/PIDLibrary
unix_guru 2:55bf0f813bb4 34 *
unix_guru 2:55bf0f813bb4 35 * The wikipedia article on PID controllers is a good place to start on
unix_guru 2:55bf0f813bb4 36 * understanding how they work:
unix_guru 2:55bf0f813bb4 37 *
unix_guru 2:55bf0f813bb4 38 * http://en.wikipedia.org/wiki/PID_controller
unix_guru 2:55bf0f813bb4 39 *
unix_guru 2:55bf0f813bb4 40 * For a clear and elegant explanation of how to implement and tune a
unix_guru 2:55bf0f813bb4 41 * controller, the controlguru website by Douglas J. Cooper (who also happened
unix_guru 2:55bf0f813bb4 42 * to be Brett's controls professor) is an excellent reference:
unix_guru 2:55bf0f813bb4 43 *
unix_guru 2:55bf0f813bb4 44 * http://www.controlguru.com/
unix_guru 2:55bf0f813bb4 45 */
unix_guru 2:55bf0f813bb4 46
arnaudsuire 0:d58c1b8d63d9 47 #ifndef PID_H
arnaudsuire 0:d58c1b8d63d9 48 #define PID_H
unix_guru 2:55bf0f813bb4 49
unix_guru 2:55bf0f813bb4 50 /**
unix_guru 2:55bf0f813bb4 51 * Includes
unix_guru 2:55bf0f813bb4 52 */
unix_guru 2:55bf0f813bb4 53 #include "mbed.h"
unix_guru 2:55bf0f813bb4 54
unix_guru 2:55bf0f813bb4 55 /**
unix_guru 2:55bf0f813bb4 56 * Defines
unix_guru 2:55bf0f813bb4 57 */
unix_guru 1:117e0c36eb22 58 #define MANUAL_MODE 0
unix_guru 1:117e0c36eb22 59 #define AUTO_MODE 1
unix_guru 2:55bf0f813bb4 60
unix_guru 2:55bf0f813bb4 61 /**
unix_guru 2:55bf0f813bb4 62 * Proportional-integral-derivative controller.
unix_guru 2:55bf0f813bb4 63 */
unix_guru 2:55bf0f813bb4 64 class PID {
unix_guru 2:55bf0f813bb4 65
arnaudsuire 0:d58c1b8d63d9 66 public:
unix_guru 2:55bf0f813bb4 67
unix_guru 2:55bf0f813bb4 68 /**
unix_guru 2:55bf0f813bb4 69 * Constructor.
unix_guru 2:55bf0f813bb4 70 *
unix_guru 2:55bf0f813bb4 71 * Sets default limits [0-3.3V], calculates tuning parameters, and sets
unix_guru 2:55bf0f813bb4 72 * manual mode with no bias.
unix_guru 2:55bf0f813bb4 73 *
unix_guru 2:55bf0f813bb4 74 * @param Kc - Tuning parameter
unix_guru 2:55bf0f813bb4 75 * @param tauI - Tuning parameter
unix_guru 2:55bf0f813bb4 76 * @param tauD - Tuning parameter
unix_guru 2:55bf0f813bb4 77 * @param interval PID calculation performed every interval seconds.
unix_guru 2:55bf0f813bb4 78 */
arnaudsuire 0:d58c1b8d63d9 79 PID(float Kc, float tauI, float tauD, float interval);
unix_guru 2:55bf0f813bb4 80
unix_guru 2:55bf0f813bb4 81 /**
unix_guru 2:55bf0f813bb4 82 * Scale from inputs to 0-100%.
unix_guru 2:55bf0f813bb4 83 *
unix_guru 2:55bf0f813bb4 84 * @param InMin The real world value corresponding to 0%.
unix_guru 2:55bf0f813bb4 85 * @param InMax The real world value corresponding to 100%.
unix_guru 2:55bf0f813bb4 86 */
unix_guru 2:55bf0f813bb4 87 void setInputLimits(float inMin , float inMax);
unix_guru 2:55bf0f813bb4 88
unix_guru 2:55bf0f813bb4 89 /**
unix_guru 2:55bf0f813bb4 90 * Scale from outputs to 0-100%.
unix_guru 2:55bf0f813bb4 91 *
unix_guru 2:55bf0f813bb4 92 * @param outMin The real world value corresponding to 0%.
unix_guru 2:55bf0f813bb4 93 * @param outMax The real world value corresponding to 100%.
unix_guru 2:55bf0f813bb4 94 */
arnaudsuire 0:d58c1b8d63d9 95 void setOutputLimits(float outMin, float outMax);
unix_guru 2:55bf0f813bb4 96
unix_guru 2:55bf0f813bb4 97 /**
unix_guru 2:55bf0f813bb4 98 * Calculate PID constants.
unix_guru 2:55bf0f813bb4 99 *
unix_guru 2:55bf0f813bb4 100 * Allows parameters to be changed on the fly without ruining calculations.
unix_guru 2:55bf0f813bb4 101 *
unix_guru 2:55bf0f813bb4 102 * @param Kc - Tuning parameter
unix_guru 2:55bf0f813bb4 103 * @param tauI - Tuning parameter
unix_guru 2:55bf0f813bb4 104 * @param tauD - Tuning parameter
unix_guru 2:55bf0f813bb4 105 */
arnaudsuire 0:d58c1b8d63d9 106 void setTunings(float Kc, float tauI, float tauD);
unix_guru 2:55bf0f813bb4 107
unix_guru 2:55bf0f813bb4 108 /**
unix_guru 2:55bf0f813bb4 109 * Reinitializes controller internals. Automatically
unix_guru 2:55bf0f813bb4 110 * called on a manual to auto transition.
unix_guru 2:55bf0f813bb4 111 */
arnaudsuire 0:d58c1b8d63d9 112 void reset(void);
unix_guru 2:55bf0f813bb4 113
unix_guru 1:117e0c36eb22 114 /**
unix_guru 1:117e0c36eb22 115 * Set PID to manual or auto mode.
unix_guru 1:117e0c36eb22 116 *
unix_guru 1:117e0c36eb22 117 * @param mode 0 -> Manual
unix_guru 1:117e0c36eb22 118 * Non-zero -> Auto
unix_guru 1:117e0c36eb22 119 */
unix_guru 1:117e0c36eb22 120 void setMode(int mode);
unix_guru 2:55bf0f813bb4 121
unix_guru 2:55bf0f813bb4 122 /**
unix_guru 2:55bf0f813bb4 123 * Set how fast the PID loop is run.
unix_guru 2:55bf0f813bb4 124 *
unix_guru 2:55bf0f813bb4 125 * @param interval PID calculation peformed every interval seconds.
unix_guru 2:55bf0f813bb4 126 */
unix_guru 2:55bf0f813bb4 127 void setInterval(float interval);
unix_guru 2:55bf0f813bb4 128
unix_guru 2:55bf0f813bb4 129 /**
unix_guru 2:55bf0f813bb4 130 * Set the set point.
unix_guru 2:55bf0f813bb4 131 *
unix_guru 2:55bf0f813bb4 132 * @param sp The set point as a real world value.
unix_guru 2:55bf0f813bb4 133 */
unix_guru 2:55bf0f813bb4 134 void setSetPoint(float sp);
unix_guru 2:55bf0f813bb4 135
unix_guru 2:55bf0f813bb4 136 /**
unix_guru 2:55bf0f813bb4 137 * Set the process value.
unix_guru 2:55bf0f813bb4 138 *
unix_guru 2:55bf0f813bb4 139 * @param pv The process value as a real world value.
unix_guru 2:55bf0f813bb4 140 */
unix_guru 2:55bf0f813bb4 141 void setProcessValue(float pv);
unix_guru 2:55bf0f813bb4 142
unix_guru 2:55bf0f813bb4 143 /**
unix_guru 2:55bf0f813bb4 144 * Set the bias.
unix_guru 2:55bf0f813bb4 145 *
unix_guru 2:55bf0f813bb4 146 * @param bias The bias for the controller output.
unix_guru 2:55bf0f813bb4 147 */
arnaudsuire 0:d58c1b8d63d9 148 void setBias(float bias);
unix_guru 2:55bf0f813bb4 149
unix_guru 2:55bf0f813bb4 150 /**
unix_guru 2:55bf0f813bb4 151 * PID calculation.
unix_guru 2:55bf0f813bb4 152 *
unix_guru 2:55bf0f813bb4 153 * @return The controller output as a float between outMin and outMax.
unix_guru 2:55bf0f813bb4 154 */
unix_guru 2:55bf0f813bb4 155 float compute(void);
unix_guru 2:55bf0f813bb4 156
arnaudsuire 0:d58c1b8d63d9 157 //Getters.
arnaudsuire 0:d58c1b8d63d9 158 float getInMin();
arnaudsuire 0:d58c1b8d63d9 159 float getInMax();
arnaudsuire 0:d58c1b8d63d9 160 float getOutMin();
arnaudsuire 0:d58c1b8d63d9 161 float getOutMax();
arnaudsuire 0:d58c1b8d63d9 162 float getInterval();
arnaudsuire 0:d58c1b8d63d9 163 float getPParam();
arnaudsuire 0:d58c1b8d63d9 164 float getIParam();
arnaudsuire 0:d58c1b8d63d9 165 float getDParam();
unix_guru 2:55bf0f813bb4 166
arnaudsuire 0:d58c1b8d63d9 167 private:
unix_guru 2:55bf0f813bb4 168
arnaudsuire 0:d58c1b8d63d9 169 bool usingFeedForward;
unix_guru 1:117e0c36eb22 170 bool inAuto;
unix_guru 2:55bf0f813bb4 171
arnaudsuire 0:d58c1b8d63d9 172 //Actual tuning parameters used in PID calculation.
arnaudsuire 0:d58c1b8d63d9 173 float Kc_;
arnaudsuire 0:d58c1b8d63d9 174 float tauR_;
arnaudsuire 0:d58c1b8d63d9 175 float tauD_;
unix_guru 2:55bf0f813bb4 176
arnaudsuire 0:d58c1b8d63d9 177 //Raw tuning parameters.
arnaudsuire 0:d58c1b8d63d9 178 float pParam_;
arnaudsuire 0:d58c1b8d63d9 179 float iParam_;
arnaudsuire 0:d58c1b8d63d9 180 float dParam_;
unix_guru 2:55bf0f813bb4 181
arnaudsuire 0:d58c1b8d63d9 182 //The point we want to reach.
unix_guru 2:55bf0f813bb4 183 float setPoint_;
arnaudsuire 0:d58c1b8d63d9 184 //The thing we measure.
unix_guru 2:55bf0f813bb4 185 float processVariable_;
arnaudsuire 0:d58c1b8d63d9 186 float prevProcessVariable_;
arnaudsuire 0:d58c1b8d63d9 187 //The output that affects the process variable.
unix_guru 2:55bf0f813bb4 188 float controllerOutput_;
arnaudsuire 0:d58c1b8d63d9 189 float prevControllerOutput_;
unix_guru 2:55bf0f813bb4 190
arnaudsuire 0:d58c1b8d63d9 191 //We work in % for calculations so these will scale from
arnaudsuire 0:d58c1b8d63d9 192 //real world values to 0-100% and back again.
arnaudsuire 0:d58c1b8d63d9 193 float inMin_;
arnaudsuire 0:d58c1b8d63d9 194 float inMax_;
arnaudsuire 0:d58c1b8d63d9 195 float inSpan_;
arnaudsuire 0:d58c1b8d63d9 196 float outMin_;
arnaudsuire 0:d58c1b8d63d9 197 float outMax_;
arnaudsuire 0:d58c1b8d63d9 198 float outSpan_;
unix_guru 2:55bf0f813bb4 199
arnaudsuire 0:d58c1b8d63d9 200 //The accumulated error, i.e. integral.
arnaudsuire 0:d58c1b8d63d9 201 float accError_;
arnaudsuire 0:d58c1b8d63d9 202 //The controller output bias.
arnaudsuire 0:d58c1b8d63d9 203 float bias_;
unix_guru 2:55bf0f813bb4 204
arnaudsuire 0:d58c1b8d63d9 205 //The interval between samples.
unix_guru 2:55bf0f813bb4 206 float tSample_;
unix_guru 2:55bf0f813bb4 207
arnaudsuire 0:d58c1b8d63d9 208 //Controller output as a real world value.
arnaudsuire 0:d58c1b8d63d9 209 volatile float realOutput_;
unix_guru 2:55bf0f813bb4 210
unix_guru 2:55bf0f813bb4 211 };
unix_guru 2:55bf0f813bb4 212
unix_guru 2:55bf0f813bb4 213 #endif /* PID_H */
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