Control Subsystem

Data Structures
struct	pid_controller_t

Typedefs
typedef struct pid_controller_t	pid_controller_t
typedef struct pid_controller_t	pid_controller_t

Functions
void	PID_Reset (pid_controller_t *pid_handle)
int32_t	PID_Step (pid_controller_t *pid_handle, int32_t meas)
float	PID_Step (pid_controller_t *pid_handle, float meas)

Detailed Description

Created on: Mar 17, 2014

Author

: Bradley Ebinger Updated on: Feb 15, 2015

: Anthony Merlino

Version

2015.02.15

Typedef Documentation

typedef struct pid_controller_t pid_controller_t

Structure to hold PID controller data

• kp, ki, and kd are the gain coefficients of the proportional, integral and derivative terms respectively
• prev_error - the error computed last time step to be used for derivative computation
• accum_error - the total accumulated error of the system to be used for integral computation
• prev_time - the last time the PID was updated, to be used for integral and derivative computations

typedef struct pid_controller_t pid_controller_t

Structure to hold PID controller data

• kp, ki, and kd are the gain coefficients of the proportional, integral and derivative terms respectively
• prev_error - the error computed last time step to be used for derivative computation
• accum_error - the total accumulated error of the system to be used for integral computation
• prev_time - the last time the PID was updated, to be used for integral and derivative computations

Function Documentation

void PID_Reset

(

pid_controller_t *

pid_handle

)

Resets the error and previous timestep of the PID controller.

Sets the gain parameters, resets the error's and time

Parameters

pid_handle	- a handle to the PID structure to initialize
curr_time	- the current time for prev_time to be reset to

float PID_Step	(	pid_controller_t *	pid_handle,
		float	meas
	)

Updates the PID controller and returns the computed output

Parameters

pid_handle	- a handle to the PID structure to update
stpt	- the setpoint of the system
meas	- the current measurement of the value

Returns

int32_t PID_Step	(	pid_controller_t *	pid_handle,
		int32_t	meas
	)

Updates the PID controller and returns the computed output

Parameters

pid_handle	- a handle to the PID structure to update
stpt	- the setpoint of the system
meas	- the current measurement of the value

Returns