Simple PID Controller with Integral Windup Supports creating a diagnostics message to send to a GUI Prints to Binary
Fork of PidControllerV2 by
Revision 6:99403113343f, committed 2018-05-07
- Comitter:
- batchee7
- Date:
- Mon May 07 05:15:19 2018 +0000
- Parent:
- 5:1206105e20bd
- Commit message:
- InitialRelease
Changed in this revision
PidController.cpp | Show annotated file Show diff for this revision Revisions of this file |
PidController.h | Show annotated file Show diff for this revision Revisions of this file |
diff -r 1206105e20bd -r 99403113343f PidController.cpp --- a/PidController.cpp Tue Oct 31 03:46:43 2017 +0000 +++ b/PidController.cpp Mon May 07 05:15:19 2018 +0000 @@ -1,37 +1,42 @@ #include "mbed.h" #include "PidController.h" -PidController::PidController(char c){ +PidController::PidController(){ elapsedTime =0; mode = MANUAL; - diagChar = c; } -float PidController::Calculate(float SP, float PV, float ManualMV) +float PidController::Calculate(float SP, float PV) { float CV; //(mm/s) Control Variable + float ProportionalAction; float IntegralAction; // Integral Contribution to Output float DerivativeAction; // Derivative Contribution to Output if (mode == MANUAL) { - CV = ManualMV; //Write Manual Manipulated Variable + CV = SP; //Write Directly to Output accumError = 0; prevError = 0; } else { //Calc error - error = SP - PV; + error = SP - PV; + ProportionalAction = K_p*error ; IntegralAction = K_i*(accumError + error); - //DerivativeAction = K_d*(PV - lastInput); DerivativeAction = K_d*(error - prevError); //-- PID Calculation if (SP) { - CV = bias + K_p*error + IntegralAction + DerivativeAction; + CV = bias + ProportionalAction + IntegralAction + DerivativeAction; if (CV>0) {CV = sqrt(CV);} + else if (CV<0) + { + CV = sqrt(CV*-1.0); + CV = CV*-1.0; + } } else { @@ -40,23 +45,27 @@ } //-- Only allow the Controller to integrate if the output isnt saturated - if ((CV < maxLimit) || (CV > minLimit)) - { - accumError += error; - } + if ((CV < maxLimit) || (CV > minLimit)){accumError += error;} //-- Save Current Input for Next Loop - //lastInput = PV; prevError = error; - - //Check to See Output is Within Limits - if (CV > maxLimit){CV= maxLimit;} - if (CV < minLimit){CV= minLimit;} } + + //Check to See Output is Within Limits + if (CV > maxLimit){CV= maxLimit;} + if (CV < minLimit){CV= minLimit;} - //-- Make message to send to GUI - if (collectDiagnostics){BuildDiagMessage(SP,PV, CV, K_p*error, IntegralAction, DerivativeAction);} + if (collectDiagnostics)//{BuildDiagMessage(SP,PV, CV, K_p*error, IntegralAction, DerivativeAction);} + { + int_to_byte(diagMsg, elapsedTime); + float_to_byte(diagMsg +2, &SP); + float_to_byte(diagMsg +6, &PV); + float_to_byte(diagMsg +10, &CV); + float_to_byte(diagMsg +14, &ProportionalAction); + float_to_byte(diagMsg +18, &IntegralAction); + float_to_byte(diagMsg +22, &DerivativeAction); + } return CV; } @@ -89,10 +98,18 @@ return; } -void PidController::BuildDiagMessage(float SetPoint, float ProcessVar, float PWM, float PropAction, float IntAction, float DifAction){ - //sprintf(diagMsg, "%c %d %0.4f %0.4f %0.1f %0.4f %0.4f %0.4f\n", diagChar, elapsedTime, SetPoint, ProcessVar, PWM, PropAction, IntAction, DifAction); - sprintf(diagMsg, "%c %d %0.4f %0.4f %0.1f 0.0 0.0 0.0\n", diagChar, elapsedTime, SetPoint, ProcessVar, PWM); - elapsedTime += RATE; +void PidController::GetDiagnosticsMessage(char *data){ + memcpy(data, &diagMsg, 27 ); return; } +//-- Helper Functions + +//-- Convert floating point to byte array +void PidController::float_to_byte(char *data, float *val) { + memcpy(data, val, sizeof(float)); +} +//-- Convert integer to byte array +void PidController::int_to_byte(char *data, uint16_t val) { + memcpy(data, &val, sizeof val); +}
diff -r 1206105e20bd -r 99403113343f PidController.h --- a/PidController.h Tue Oct 31 03:46:43 2017 +0000 +++ b/PidController.h Mon May 07 05:15:19 2018 +0000 @@ -28,22 +28,14 @@ * * * - - * @code -#include "mbed.h" -#include "PID.h" - - * @endcode */ - - #ifndef PidController_H #define PidController_H #include "mbed.h" //-- Constants used in system -const int RATE = 20; //--(ms) Time that Calculate mehtod is being called +const int RATE = 100; //--(ms) Time that Calculate mehtod is being called const int AUTOMATIC = 0; //-- In automatic then PID Controls Output const int MANUAL = 1; //-- In Manual then User Controls Output directly @@ -53,17 +45,15 @@ public: // Public Methods - /** Constructor - * - */ - PidController(char); + // Constructor + PidController(); /** Performs the PID Calculation * @param SP - Setpoint (target value) units depends on what PID is controlling * @param PV - Process Variable (feedback/ measure value) units depends on what PID is controlling - * @return Returns If Controller is in Automatic then returns PID controlled signal. In manual returns the user SP multipled by scalar. + * @return Returns If Controller is in Automatic then returns PID controlled signal. In manual returns the user SP. */ - float Calculate(float SP, float PV, float ManualMV); + float Calculate(float SP, float PV); /** Update Internal Settings * @param Bias - Added to the PID Calculation @@ -103,37 +93,37 @@ */ void EndDiag(void); - /** Build a string to send back to HMI to Graph PID - */ - void BuildDiagMessage(float SP, float PV, float PWM, float PropAction, float IntAction, float DifAction); - /** Check to see if the controller is collecting diagnostics data * @return true then a diagnostics message is been created. */ bool DiagnosticsEnabled(void){return collectDiagnostics;} - int GetElapsedtime(void){return elapsedTime;} - - // Made Public as im lazy - char diagMsg[65]; + /** Check to see if the controller is collecting diagnostics data + * @param Data - Starting address of target recieve buffer (must be at least 25char long) + */ + void GetDiagnosticsMessage(char *data); private: bool mode; - //-- For Diagnostics to GUI bool collectDiagnostics; - int elapsedTime; + uint16_t elapsedTime; + char diagMsg[28]; + + //-- Settings + float bias; + float minLimit, maxLimit; + float K_p,K_i,K_d; //-- For PID Calculations - char diagChar; - float bias; float error; - float lastInput; float accumError; - float minLimit, maxLimit; - float K_p,K_i,K_d; float prevError; - }; + + //-- Private Helper functions + void float_to_byte(char *data, float *val); + void int_to_byte(char *data, uint16_t val); + }; #endif