PID Class Reference

Generic PID controller class. More...

#include <common/common.hh>

Public Member Functions
	PID (double _p=0.0, double _i=0.0, double _d=0.0, double _imax=0.0, double _imin=0.0, double _cmdMax=-1.0, double _cmdMin=0.0)
	Constructor, zeros out Pid values when created and initialize Pid-gains and integral term limits:[iMax:iMin]-[I1:I2]. More...
virtual	~PID ()
	Destructor. More...
double	GetCmd ()
	Return current command for this PID controller. More...
double	GetCmdMax () const
	Get the maximum value for the command. More...
double	GetCmdMin () const
	Get the maximum value for the command. More...
double	GetDGain () const
	Get the derivative Gain. More...
void	GetErrors (double &_pe, double &_ie, double &_de)
	Return PID error terms for the controller. More...
double	GetIGain () const
	Get the integral Gain. More...
double	GetIMax () const
	Get the integral upper limit. More...
double	GetIMin () const
	Get the integral lower limit. More...
double	GetPGain () const
	Get the proportional Gain. More...
void	Init (double _p=0.0, double _i=0.0, double _d=0.0, double _imax=0.0, double _imin=0.0, double _cmdMax=-1.0, double _cmdMin=0.0)
	Initialize PID-gains and integral term limits:[iMax:iMin]-[I1:I2]. More...
PID &	operator= (const PID &_p)
	Assignment operator. More...
void	Reset ()
	Reset the errors and command. More...
void	SetCmd (double _cmd)
	Set current target command for this PID controller. More...
void	SetCmdMax (double _c)
	Set the maximum value for the command. More...
void	SetCmdMin (double _c)
	Set the maximum value for the command. More...
void	SetDGain (double _d)
	Set the derivtive Gain. More...
void	SetIGain (double _i)
	Set the integral Gain. More...
void	SetIMax (double _i)
	Set the integral upper limit. More...
void	SetIMin (double _i)
	Set the integral lower limit. More...
void	SetPGain (double _p)
	Set the proportional Gain. More...
double	Update (double _error, common::Time _dt)
	Update the Pid loop with nonuniform time step size. More...

Detailed Description

Generic PID controller class.

Generic proportiolnal-integral-derivative controller class that keeps track of PID-error states and control inputs given the state of a system and a user specified target state.

Constructor & Destructor Documentation

PID	(	double	_p = 0.0,
		double	_i = 0.0,
		double	_d = 0.0,
		double	_imax = 0.0,
		double	_imin = 0.0,
		double	_cmdMax = -1.0,
		double	_cmdMin = 0.0
	)

Constructor, zeros out Pid values when created and initialize Pid-gains and integral term limits:[iMax:iMin]-[I1:I2].

Disable command clamping by setting _cmdMin to a value larger than _cmdMax. Command clamping is disabled by default.

Parameters

[in]	_p	The proportional gain.
[in]	_i	The integral gain.
[in]	_d	The derivative gain.
[in]	_imax	The integral upper limit.
[in]	_imin	The integral lower limit.
[in]	_cmdMax	Output max value.
[in]	_cmdMin	Output min value.

virtual ~PID ( )

virtual

Destructor.

Member Function Documentation

double GetCmd

(

)

Return current command for this PID controller.

Returns

the command value

double GetCmdMax

(

)

const

Get the maximum value for the command.

Returns

The maximum value

double GetCmdMin

(

)

const

Get the maximum value for the command.

Returns

The maximum value

double GetDGain

(

)

const

Get the derivative Gain.

Returns

The derivative gain value

void GetErrors	(	double &	_pe,
		double &	_ie,
		double &	_de
	)

Return PID error terms for the controller.

Parameters

[in]	_pe	The proportional error.
[in]	_ie	The integral error.
[in]	_de	The derivative error.

double GetIGain

(

)

const

Get the integral Gain.

Returns

The integral gain value

double GetIMax

(

)

const

Get the integral upper limit.

Returns

The integral upper limit value

double GetIMin

(

)

const

Get the integral lower limit.

Returns

The integral lower limit value

double GetPGain

(

)

const

Get the proportional Gain.

Returns

The proportional gain value

void Init	(	double	_p = 0.0,
		double	_i = 0.0,
		double	_d = 0.0,
		double	_imax = 0.0,
		double	_imin = 0.0,
		double	_cmdMax = -1.0,
		double	_cmdMin = 0.0
	)

Initialize PID-gains and integral term limits:[iMax:iMin]-[I1:I2].

Disable command clamping by setting _cmdMin to a value larger than _cmdMax. Command clamping is disabled by default.

Parameters

[in]	_p	The proportional gain.
[in]	_i	The integral gain.
[in]	_d	The derivative gain.
[in]	_imax	The integral upper limit.
[in]	_imin	The integral lower limit.
[in]	_cmdMax	Output max value.
[in]	_cmdMin	Output min value.

PID& operator= ( const PID &  _p )

inline

Assignment operator.

Parameters

[in]

_p

a reference to a PID to assign values from

Returns

reference to this instance

References PID::Reset().

void Reset

(

)

Reset the errors and command.

Referenced by PID::operator=().

void SetCmd

(

double

_cmd

)

Set current target command for this PID controller.

Parameters

[in]

_cmd

New command

void SetCmdMax

(

double

_c

)

Set the maximum value for the command.

Parameters

[in]

_c

The maximum value

void SetCmdMin

(

double

_c

)

Set the maximum value for the command.

Parameters

[in]

_c

The maximum value

void SetDGain

(

double

_d

)

Set the derivtive Gain.

Parameters

[in]

_p

dertivative gain value

void SetIGain

(

double

_i

)

Set the integral Gain.

Parameters

[in]

_p

integral gain value

void SetIMax

(

double

_i

)

Set the integral upper limit.

Parameters

[in]

_p

integral upper limit value

void SetIMin

(

double

_i

)

Set the integral lower limit.

Parameters

[in]

_p

integral lower limit value

void SetPGain

(

double

_p

)

Set the proportional Gain.

Parameters

[in]

_p

proportional gain value

double Update	(	double	_error,
		common::Time	_dt
	)

Update the Pid loop with nonuniform time step size.

Parameters

_in]	_error Error since last call (p_state - p_target).
_in]	_dt Change in time since last update call. Normally, this is called at every time step, The return value is an updated command to be passed to the object being controlled.

Returns

the command value

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

• PID.hh