Tony Lin
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BX-car
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Diff: controller.h
- Revision:
- 7:fd976e1ced33
- Child:
- 8:8e49e21d80a2
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/controller.h Sun Jun 22 13:58:01 2014 +0000 @@ -0,0 +1,119 @@ +#include "mbed.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_; + +};