get set point
Fork of PID by
PID.h
- Committer:
- vsutardja
- Date:
- 2016-04-24
- Revision:
- 2:ee6bcde54713
- Parent:
- 0:6e12a3e5af19
File content as of revision 2:ee6bcde54713:
/** * @author Aaron Berk * * @section LICENSE * * Copyright (c) 2010 ARM Limited * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. * * @section DESCRIPTION * * A PID controller is a widely used feedback controller commonly found in * industry. * * This library is a port of Brett Beauregard's Arduino PID library: * * http://www.arduino.cc/playground/Code/PIDLibrary * * The wikipedia article on PID controllers is a good place to start on * understanding how they work: * * http://en.wikipedia.org/wiki/PID_controller * * For a clear and elegant explanation of how to implement and tune a * controller, the controlguru website by Douglas J. Cooper (who also happened * to be Brett's controls professor) is an excellent reference: * * http://www.controlguru.com/ */ #ifndef PID_H #define PID_H /** * Includes */ #include "mbed.h" /** * Defines */ #define MANUAL_MODE 0 #define AUTO_MODE 1 /** * Proportional-integral-derivative controller. */ class PID { public: /** * Constructor. * * Sets default limits [0-3.3V], calculates tuning parameters, and sets * manual mode with no bias. * * @param Kc - Tuning parameter * @param tauI - Tuning parameter * @param tauD - Tuning parameter * @param interval PID calculation performed every interval seconds. */ PID(float Kc, float tauI, float tauD, float interval); /** * Scale from inputs to 0-100%. * * @param InMin The real world value corresponding to 0%. * @param InMax The real world value corresponding to 100%. */ void setInputLimits(float inMin , float inMax); /** * Scale from outputs to 0-100%. * * @param outMin The real world value corresponding to 0%. * @param outMax The real world value corresponding to 100%. */ void setOutputLimits(float outMin, float outMax); /** * Calculate PID constants. * * Allows parameters to be changed on the fly without ruining calculations. * * @param Kc - Tuning parameter * @param tauI - Tuning parameter * @param tauD - Tuning parameter */ void setTunings(float Kc, float tauI, float tauD); /** * Reinitializes controller internals. Automatically * called on a manual to auto transition. */ void reset(void); /** * Set PID to manual or auto mode. * * @param mode 0 -> Manual * Non-zero -> Auto */ void setMode(int mode); /** * Set how fast the PID loop is run. * * @param interval PID calculation peformed every interval seconds. */ void setInterval(float interval); /** * Set the set point. * * @param sp The set point as a real world value. */ void setSetPoint(float sp); /** * Set the process value. * * @param pv The process value as a real world value. */ void setProcessValue(float pv); /** * Set the bias. * * @param bias The bias for the controller output. */ void setBias(float bias); /** * PID calculation. * * @return The controller output as a float between outMin and outMax. */ float compute(void); //Getters. float getInMin(); float getInMax(); float getOutMin(); float getOutMax(); float getInterval(); float getPParam(); float getIParam(); float getDParam(); float getSetPoint(); private: bool usingFeedForward; bool inAuto; //Actual tuning parameters used in PID calculation. float Kc_; float tauR_; float tauD_; //Raw tuning parameters. float pParam_; float iParam_; float dParam_; //The point we want to reach. float setPoint_; //The thing we measure. float processVariable_; float prevProcessVariable_; //The output that affects the process variable. float controllerOutput_; float prevControllerOutput_; //We work in % for calculations so these will scale from //real world values to 0-100% and back again. float inMin_; float inMax_; float inSpan_; float outMin_; float outMax_; float outSpan_; //The accumulated error, i.e. integral. float accError_; //The controller output bias. float bias_; //The interval between samples. float tSample_; //Controller output as a real world value. volatile float realOutput_; }; #endif /* PID_H */