Improved fork of Proportional, integral, derivative controller library. Ported by Aaron Berk from the Arduino PID library by Brett Beauregard.

Fork of PID by Aaron Berk

Files at this revision

API Documentation at this revision

Comitter:
dzoni
Date:
Wed Mar 28 09:30:47 2018 +0000
Parent:
0:6e12a3e5af19
Commit message:
Solved all compile time warnings (floats).

Changed in this revision

PID.cpp Show annotated file Show diff for this revision Revisions of this file
--- a/PID.cpp	Thu Sep 02 16:48:10 2010 +0000
+++ b/PID.cpp	Wed Mar 28 09:30:47 2018 +0000
@@ -57,23 +57,23 @@
     //Default the limits to the full range of I/O: 3.3V
     //Make sure to set these to more appropriate limits for
     //your application.
-    setInputLimits(0.0, 3.3);
-    setOutputLimits(0.0, 3.3);
+    setInputLimits(0.0f, 3.3f);
+    setOutputLimits(0.0f, 3.3f);
 
     tSample_ = interval;
 
     setTunings(Kc, tauI, tauD);
 
-    setPoint_             = 0.0;
-    processVariable_      = 0.0;
-    prevProcessVariable_  = 0.0;
-    controllerOutput_     = 0.0;
-    prevControllerOutput_ = 0.0;
+    setPoint_             = 0.0f;
+    processVariable_      = 0.0f;
+    prevProcessVariable_  = 0.0f;
+    controllerOutput_     = 0.0f;
+    prevControllerOutput_ = 0.0f;
 
-    accError_ = 0.0;
-    bias_     = 0.0;
+    accError_ = 0.0f;
+    bias_     = 0.0f;
     
-    realOutput_ = 0.0;
+    realOutput_ = 0.0f;
 
 }
 
@@ -89,10 +89,10 @@
     accError_            *= (inMax - inMin) / inSpan_;
 
     //Make sure the working variables are within the new limits.
-    if (prevProcessVariable_ > 1) {
-        prevProcessVariable_ = 1;
-    } else if (prevProcessVariable_ < 0) {
-        prevProcessVariable_ = 0;
+    if (prevProcessVariable_ > 1.0f) {
+        prevProcessVariable_ = 1.0f;
+    } else if (prevProcessVariable_ < 0.0f) {
+        prevProcessVariable_ = 0.0f;
     }
 
     inMin_  = inMin;
@@ -112,10 +112,10 @@
     prevControllerOutput_ *= (outMax - outMin) / outSpan_;
 
     //Make sure the working variables are within the new limits.
-    if (prevControllerOutput_ > 1) {
-        prevControllerOutput_ = 1;
-    } else if (prevControllerOutput_ < 0) {
-        prevControllerOutput_ = 0;
+    if (prevControllerOutput_ > 1.0f) {
+        prevControllerOutput_ = 1.0f;
+    } else if (prevControllerOutput_ < 0.0f) {
+        prevControllerOutput_ = 0.0f;
     }
 
     outMin_  = outMin;
@@ -127,7 +127,7 @@
 void PID::setTunings(float Kc, float tauI, float tauD) {
 
     //Verify that the tunings make sense.
-    if (Kc == 0.0 || tauI < 0.0 || tauD < 0.0) {
+    if (Kc == 0.0f || tauI < 0.0f || tauD < 0.0f) {
         return;
     }
 
@@ -138,16 +138,16 @@
 
     float tempTauR;
 
-    if (tauI == 0.0) {
-        tempTauR = 0.0;
+    if (tauI == 0.0f) {
+        tempTauR = 0.0f;
     } else {
-        tempTauR = (1.0 / tauI) * tSample_;
+        tempTauR = (1.0f / tauI) * tSample_;
     }
 
     //For "bumpless transfer" we need to rescale the accumulated error.
     if (inAuto) {
-        if (tempTauR == 0.0) {
-            accError_ = 0.0;
+        if (tempTauR == 0.0f) {
+            accError_ = 0.0f;
         } else {
             accError_ *= (Kc_ * tauR_) / (Kc * tempTauR);
         }
@@ -161,7 +161,7 @@
 
 void PID::reset(void) {
 
-    float scaledBias = 0.0;
+    float scaledBias = 0.0f;
 
     if (usingFeedForward) {
         scaledBias = (bias_ - outMin_) / outSpan_;
@@ -173,7 +173,7 @@
     prevProcessVariable_  = (processVariable_ - inMin_) / inSpan_;
 
     //Clear any error in the integral.
-    accError_ = 0;
+    accError_ = 0.0f;
 
 }
 
@@ -191,7 +191,7 @@
 
 void PID::setInterval(float interval) {
 
-    if (interval > 0) {
+    if (interval > 0.0f) {
         //Convert the time-based tunings to reflect this change.
         tauR_     *= (interval / tSample_);
         accError_ *= (tSample_ / interval);
@@ -225,31 +225,31 @@
     //Pull in the input and setpoint, and scale them into percent span.
     float scaledPV = (processVariable_ - inMin_) / inSpan_;
 
-    if (scaledPV > 1.0) {
-        scaledPV = 1.0;
-    } else if (scaledPV < 0.0) {
-        scaledPV = 0.0;
+    if (scaledPV > 1.0f) {
+        scaledPV = 1.0f;
+    } else if (scaledPV < 0.0f) {
+        scaledPV = 0.0f;
     }
 
     float scaledSP = (setPoint_ - inMin_) / inSpan_;
-    if (scaledSP > 1.0) {
-        scaledSP = 1;
-    } else if (scaledSP < 0.0) {
-        scaledSP = 0;
+    if (scaledSP > 1.0f) {
+        scaledSP = 1.0f;
+    } else if (scaledSP < 0.0f) {
+        scaledSP = 0.0f;
     }
 
     float error = scaledSP - scaledPV;
 
     //Check and see if the output is pegged at a limit and only
     //integrate if it is not. This is to prevent reset-windup.
-    if (!(prevControllerOutput_ >= 1 && error > 0) && !(prevControllerOutput_ <= 0 && error < 0)) {
+    if (!(prevControllerOutput_ >= 1.0f && error > 0.0f) && !(prevControllerOutput_ <= 0.0f && error < 0.0f)) {
         accError_ += error;
     }
 
     //Compute the current slope of the input signal.
     float dMeas = (scaledPV - prevProcessVariable_) / tSample_;
 
-    float scaledBias = 0.0;
+    float scaledBias = 0.0f;
 
     if (usingFeedForward) {
         scaledBias = (bias_ - outMin_) / outSpan_;
@@ -259,10 +259,10 @@
     controllerOutput_ = scaledBias + Kc_ * (error + (tauR_ * accError_) - (tauD_ * dMeas));
 
     //Make sure the computed output is within output constraints.
-    if (controllerOutput_ < 0.0) {
-        controllerOutput_ = 0.0;
-    } else if (controllerOutput_ > 1.0) {
-        controllerOutput_ = 1.0;
+    if (controllerOutput_ < 0.0f) {
+        controllerOutput_ = 0.0f;
+    } else if (controllerOutput_ > 1.0f) {
+        controllerOutput_ = 1.0f;
     }
 
     //Remember this output for the windup check next time.