mcx::control3::PID Class Reference

The PID Control Object provides a PID controller with Proportional, Derivative and Integral action. More...

#include <ctrl_pid.h>

Public Member Functions
void	setError (double error)
	Sets the error input signal. More...
void	setActual (double actual)
	Sets the actual (feedback) signal. More...
double	getOutput () const
	Returns the output signal. More...
void	setKp (double kp)
	Sets the proportional gain. More...
void	setKi (double ki)
	Sets the integral gain. More...
void	setKd (double kd)
	Sets the derivative gain. More...
void	setIMax (double iMax)
	Sets the upper limit for the integral term. More...
void	setIReset (bool iReset)
	Sets the reset signal that zeros the integral action. More...

Detailed Description

The PID Control Object provides a PID controller with Proportional, Derivative and Integral action.

The controller acts on the error signal that is the input of the controller. The output \( u(t) \) is calculated according to:

\( u(t) = K_\text{p} e(t) + K_\text{i} \int_0^t e(t') \,dt' + K_\text{d} \frac{de(t)}{dt} \).

where \( e \) is the error signal, and \( K_\text{p} \), \( K_\text{i} \) and \( K_\text{d} \) are the proportional, derivative and integral gains respectively.

\u200b

Parameters

[in]	error	- the error signal, which is the difference between the reference (command value) and the actual value of signal we are trying to control
[in]	actual	- the actual value of signal we are trying to control, it is only used to determine if the actual signal is beyond the velocity threshold of the reference signal. If the velocity threshold is set to zer this input can be left at zero.
[in]	iReset	- reset signal for the integral action. The integrator output is set to zero when this signal is true.
[out]	output	- the controller output signal
[out]	iTerm	- the current value of the integral term
[out]	dTerm	- the current value of the derivative term
	kp	- the proportional gain
	ki	- the integral gain
	kd	- the derivative gain
	iMin	- lower limit value of the integral action
	iMax	- upper limit value of the integral action
	iPositionErrorThresholdNeg	- lower threshold value of the error for enabling the integral action
	iPositionErrorThresholdPos	- upper threshold value of the error for enabling the integral action
	iActualVelocityThresholdNeg	- lower threshold value of the actual velocity for enabling the integral action
	iActualVelocityThresholdPos	- upper threshold value of the actual velocity for enabling the integral action
	iMin	- lower limit for the integral action
	iMax	- upper limit for the integral action

Member Function Documentation

getOutput()

double mcx::control3::PID::getOutput ( ) const

inline

Returns the output signal.

Returns

actual value of the output.

setActual()

void mcx::control3::PID::setActual ( double  actual )

inline

Sets the actual (feedback) signal.

Parameters

actual

- new value of the actual signal.

setError()

void mcx::control3::PID::setError ( double  error )

inline

Sets the error input signal.

Parameters

error

- new value of the error signal.

setIMax()

void mcx::control3::PID::setIMax ( double  iMax )

inline

Sets the upper limit for the integral term.

Parameters

iMax	- new value of the upper limit for the integral gain.

setIReset()

void mcx::control3::PID::setIReset ( bool  iReset )

inline

Sets the reset signal that zeros the integral action.

Parameters

iReset

- reset signal

setKd()

void mcx::control3::PID::setKd ( double  kd )

inline

Sets the derivative gain.

Parameters

kd	- new value of the derivative gain.

setKi()

void mcx::control3::PID::setKi ( double  ki )

inline

Sets the integral gain.

Parameters

ki	- new value of the integral gain.

setKp()

void mcx::control3::PID::setKp ( double  kp )

inline

Sets the proportional gain.

Parameters

kp	- new value of the proportional gain.

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

• control/ctrl_pid.h
• control/ctrl_pid.cpp