PidIndustrial Class Reference

#include <efi_pid.h>

Inheritance diagram for PidIndustrial:

Collaboration diagram for PidIndustrial:

Public Member Functions
	PidIndustrial ()
	PidIndustrial (pid_s *pid)
float	getOutput (float target, float input, float dTime) override
float	getOutput (float target, float input)
virtual float	getOutput (float target, float input, float dTime)
Public Member Functions inherited from Pid
	Pid ()
	Pid (pid_s *parameters)
void	initPidClass (pid_s *parameters)
bool	isSame (const pid_s *parameters) const
float	getOutput (float target, float input)
float	getUnclampedOutput (float target, float input, float dTime)
void	updateFactors (float pFactor, float iFactor, float dFactor)
virtual void	reset ()
float	getP () const
float	getI () const
float	getD () const
float	getOffset () const
float	getMinValue () const
float	getIntegration (void) const
float	getPrevError (void) const
void	setErrorAmplification (float coef)
void	postState (pid_status_s &pidStatus) const
void	showPidStatus (const char *msg) const
void	sleep ()

Data Fields
float	antiwindupFreq = 0.0f
float	derivativeFilterLoss = 0.0f
Data Fields inherited from Pid
int	resetCounter
float	iTermMin = -1000000.0
float	iTermMax = 1000000.0
Data Fields inherited from pid_state_s
float	iTerm = (float)0
float	dTerm = (float)0
float	target = (float)0
float	input = (float)0
float	output = (float)0
float	errorAmplificationCoef = (float)0
float	previousError = (float)0

Private Member Functions
float	limitOutput (float v) const

Additional Inherited Members
Protected Member Functions inherited from Pid
virtual void	updateITerm (float value)
Protected Attributes inherited from Pid
pid_s *	parameters = nullptr

Detailed Description

A PID with derivative filtering (backward differences) and integrator anti-windup. See: Wittenmark B., Astrom K., Arzen K. IFAC Professional Brief. Computer Control: An Overview. Two additional parameters used: derivativeFilterLoss and antiwindupFreq (If both are 0, then this controller is identical to PidParallelController)

TODO: should PidIndustrial replace all usages of Pid/PidParallelController?

Definition at line 113 of file efi_pid.h.

Constructor & Destructor Documentation

PidIndustrial() [1/2]

PidIndustrial::PidIndustrial

(

)

Definition at line 243 of file efi_pid.cpp.

                             : Pid() {
}

PidIndustrial() [2/2]

PidIndustrial::PidIndustrial ( pid_s *  pid )

explicit

Definition at line 246 of file efi_pid.cpp.

                                                : Pid(p_parameters) {
}

Member Function Documentation

getOutput() [1/3]

float Pid::getOutput	(	float	p_target,
		float	p_input
	)

This version of the method takes dTime from pid_s

Parameters

Controller

input / process output

Returns

Output from the PID controller / the input to the process

Parameters

Controller

input / process output

Returns

Output from the PID controller / the input to the process

Definition at line 47 of file efi_pid.cpp.

                                                  {
  efiAssert(ObdCode::OBD_PCM_Processor_Fault, parameters != nullptr, "PID::getOutput nullptr", 0);
    float dTime = MS2SEC(GET_PERIOD_LIMITED(parameters));
    return getOutput(p_target, p_input, dTime);
}

getOutput() [2/3]

float Pid::getOutput ( float  p_target, float  p_input, float  dTime  )

virtual

Parameters

dTime

seconds probably? :)

Reimplemented from Pid.

Definition at line 48 of file efi_pid.cpp.

                                                               {
    float l_output = getUnclampedOutput(p_target, p_input, dTime);
 
    if (l_output > parameters->maxValue) {
        l_output = parameters->maxValue;
    } else if (l_output < getMinValue()) {
        l_output = getMinValue();
    }
    output = l_output;
    return output;
}

getOutput() [3/3]

float PidIndustrial::getOutput ( float  p_target, float  p_input, float  dTime  )

overridevirtual

Parameters

dTime

seconds probably? :)

Reimplemented from Pid.

Definition at line 249 of file efi_pid.cpp.

                                                                         {
    float ad, bd;
    float error = (p_target - p_input) * errorAmplificationCoef;
    float pTerm = parameters->pFactor * error;
 
    // calculate dTerm coefficients
    if (fabsf(derivativeFilterLoss) > DBL_EPSILON) {
        // restore Td in the Standard form from the Parallel form: Td = Kd / Kc
        float Td = parameters->dFactor / parameters->pFactor;
        // calculate the backward differences approximation of the derivative term
        ad = Td / (Td + dTime / derivativeFilterLoss);
        bd = parameters->pFactor * ad / derivativeFilterLoss;
    } else {
        // According to the Theory of limits, if p.derivativeFilterLoss -> 0, then
        //   lim(ad) = 0; lim(bd) = p.pFactor * Td / dTime = p.dFactor / dTime
        //   i.e. dTerm becomes equal to Pid's
        ad = 0.0f;
        bd = parameters->dFactor / dTime;
    }
 
    // (error - previousError) = (target-input) - (target-prevousInput) = -(input - prevousInput)
    dTerm = dTerm * ad + (error - previousError) * bd;
 
    updateITerm(parameters->iFactor * dTime * error);
 
    // calculate output and apply the limits
    float l_output = pTerm + iTerm + dTerm + getOffset();
    float limitedOutput = limitOutput(l_output);
 
    // apply the integrator anti-windup on top of the "normal" iTerm change above
    // If p.antiwindupFreq = 0, then iTerm is equal to PidParallelController's
    iTerm += dTime * antiwindupFreq * (limitedOutput - l_output);
 
    // update the state
    previousError = error;
 
    return limitedOutput;
}

Referenced by LuaIndustrialPid::get().

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limitOutput()

float PidIndustrial::limitOutput ( float  v ) const

private

Definition at line 288 of file efi_pid.cpp.

                                              {
    if (v < getMinValue())
        v = getMinValue();
    if (v > parameters->maxValue)
        v = parameters->maxValue;
    return v;
}

Referenced by getOutput().

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Field Documentation

antiwindupFreq

float PidIndustrial::antiwindupFreq = 0.0f

Definition at line 123 of file efi_pid.h.

Referenced by IdleController::getClosedLoop(), getOutput(), and LuaIndustrialPid::setAntiwindupFreq().

derivativeFilterLoss

float PidIndustrial::derivativeFilterLoss = 0.0f

Definition at line 124 of file efi_pid.h.

Referenced by IdleController::getClosedLoop(), getOutput(), and LuaIndustrialPid::setDerivativeFilterLoss().

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The documentation for this class was generated from the following files:

• util/math/efi_pid.h
• util/math/efi_pid.cpp