Diff: PID.h

Revision:

0:d58c1b8d63d9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PID.h	Wed Feb 26 08:46:04 2014 +0000
@@ -0,0 +1,123 @@
+#pragma once
+
+#ifndef PID_H
+#define PID_H
+
+class PID
+{
+public:
+
+    /*
+    * Constructeur
+    * Sets default limits, 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 how fast the PID loop is run.
+    * @param interval PID calculation peformed every interval seconds.
+    */
+    void setInterval(float interval);
+
+    /*
+    * 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(float pv, float sp);
+
+    //Getters.
+    float getInMin();
+    float getInMax();
+    float getOutMin();
+    float getOutMax();
+    float getInterval();
+    float getPParam();
+    float getIParam();
+    float getDParam();
+
+private:
+    
+    bool usingFeedForward;
+
+    //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 
+