PID controller

Collaboration diagram for PID controller:

Data Structures
struct	pid_controller_t
	PID controller instance data. More...

Functions
void	PidInit (struct pid_controller_t *Pid, float K, float Ti, float Td, float MinIntegral, float MaxIntegral)
	Initialize PID controller data. Function gets standard coefficients from PID formula: f(n) = K * ( Error(n) + SUM(Error(0) * dt(0)...Error(n) * dt(n)) / Ti + Td * Error(n) / dt(n)) More...
void	PidReset (struct pid_controller_t *Pid)
	Reset PID controller. More...
float	PidFunc (struct pid_controller_t *Pid, float Error, float ErrorDiff, float TimeDelta)
	Calculate PID function. More...

Detailed Description

Function Documentation

void PidInit	(	struct pid_controller_t *	Pid,
		float	K,
		float	Ti,
		float	Td,
		float	MinIntegral,
		float	MaxIntegral
	)

Initialize PID controller data. Function gets standard coefficients from PID formula: f(n) = K * ( Error(n) + SUM(Error(0) * dt(0)...Error(n) * dt(n)) / Ti + Td * Error(n) / dt(n))

Parameters

Pid	Pointer to PID controller data
K	K coefficient from standard PID formula.
Ti	Ti coefficient from standard PID formula.
Td	Td coefficient from standard PID formula.
MinIntegral	Minimal allowed integrated part value.
MaxIntegral	Maximal allowed integrated part value.

void PidReset ( struct pid_controller_t *  Pid )

inline

Reset PID controller.

Parameters

Pid	Pointer to PID controller data

Definition at line 91 of file pid-controller.h.

References pid_controller_t::IntegralValue, PidFunc(), and pid_controller_t::PreviousErrorDiff.

float PidFunc	(	struct pid_controller_t *	Pid,
		float	Error,
		float	ErrorDiff,
		float	TimeDelta
	)

Calculate PID function.

Parameters

Pid	Pointer to PID controller data
Error	Desired value minus current value
ErrorDiff	Error for differencial part. For classic PID it should be set equal to Error. To avoid peak output on sharp desired value change, tis can be set to (-) current value.
TimeDelta	Time between this and previous Error calculation/measurement.

Returns

Calculated PID value

Referenced by PidReset().