pid_lib.h File Reference

Public Interface for the Proportional-Integral-Derivative (PID) Controller. More...

#include <linux/aquosa/qos_types.h>

Defines
#define	PID_DEF_TARGET_SE 0
	Default target scheduling error for PID controller.
#define	PID_DEF_Z1 0.01
	Default first pole (Z1) for PID controller.
#define	PID_DEF_Z2 0.4
	Default second pole (Z2) for PID controller.
Functions
qos_rv	pid_set_defaults ()
	Configures a Proportional-Integral-Derivative controller with default parameters.
qos_rv	pid_set_target_se (qres_time_t target_se)
	Sets the target scheduling error value.
qos_rv	pid_set_poles (double z1, double z2)
	Sets the two control poles.
qos_rv	pid_register_lib (void)
	Registration of the submodule with the library.

Detailed Description

Public Interface for the Proportional-Integral-Derivative (PID) Controller.

The PID controller aims at choosing the next bandwidth assignment $ b_k $ such that the expected next-step scheduling error, conditioned to the current system state, be equal to a prefixed target value $\hat{\epsilon}$ , i.e. such that $E \big[ \mathcal{E}_{k+1} | \mathcal{E}_k = \epsilon_k \big] =\hat{\epsilon}$ . In the discrete-time, state-continuous model for the system evolution this corresponds to setting:

$b_k=\frac{\mu_k}{T+\hat{\epsilon}}$ , if $\epsilon_k \leq 0$ ;
$b_k=\frac{\mu_k}{T+\hat{\epsilon}-\epsilon_k}$ , if $0 < \epsilon_k \leq T+\hat{\epsilon}-\frac{\mu_{C_k}}{B_H}$ ;
, if $\epsilon_k > T+\hat{\epsilon}-\frac{\mu_{C_k}}{B_H}$

Requires a predictor that only provides the get_exp_value() statistic.

Definition in file pid_lib.h.

Function Documentation

qos_rv pid_register_lib ( void )

Registration of the submodule with the library.

pid_lib.h File Reference

Defines

Functions

Detailed Description

Function Documentation