Lib / PID regulator

Proportionnal-integral-derivative regulator with integrator saturation capability. More...

Data Structures
struct	pid_Pid
	PID regulator structure. More...

Functions
void	pid_Init (pid_Pid *pid, float32_t kp, float32_t ki, float32_t kd, float32_t arw, float32_t feedforward)
	Initialize the PID structure. More...
float32_t	pid_Step (pid_Pid *pid, float32_t current, float32_t target, float32_t dt)
	Step the PID structure. More...

Detailed Description

Proportionnal-integral-derivative regulator with integrator saturation capability.

First, instantiate a pid_Pid structure (e.g. "pid_Pid pid;"), then initialize it once with pid_Init(). Then, every time a new command needs to be computed (typically when a new measurement arrives), call pid_Step().

Function Documentation

pid_Init()

void pid_Init	(	pid_Pid *	pid,
		float32_t	kp,
		float32_t	ki,
		float32_t	kd,
		float32_t	arw,
		float32_t	feedforward
	)

Initialize the PID structure.

Parameters

pid	pointer to the PID structure.
kp	proportionnal coefficient of the PID. No effect if zero.
ki	integral coefficient of the PID. No effect if zero.
kd	derivative coefficient of the PID. No effect if zero.
arw	maximum value of the integrator (anti-reset windup). Disabled if negative.
feedforward	component proportional to the target (not the error). No effect if zero.

pid_Step()

float32_t pid_Step	(	pid_Pid *	pid,
		float32_t	current,
		float32_t	target,
		float32_t	dt
	)

Step the PID structure.

Parameters

pid	pointer to the PID structure.
current	current state of the system to control.
target	target state of the system to control.
dt	timestep (time since the last call of this function) [s].

Return values

command

to apply to the system.