Functions which handle the PID-control. More...

Macros
#define	RAMP
	ramp for speed [tics/s^2]

Functions
uint8_t	pid_control_init (float Kp, float Ki, float Kd, int freq)

void	pid_control_use_ramp (uint8_t ramp)

void	pid_control_set_sp (int16_t v_desired)

int16_t	pid_control_sp (void)

void	pid_control_set_Kp (float Kp)

void	pid_control_set_Ki (float Ki)

void	pid_control_set_Kd (float Kd)

float	pid_control_Kp (void)

float	pid_control_Ki (void)

float	pid_control_Kd (void)

void	pid_control_reset (void)

void	pid_control_stop (void)

Detailed Description

Functions which handle the PID-control.

This additional module is designed for simple pid-controller tests. It is only supposed to be a starting point for your own code. Therefore, all functions are not optimized at all. To underline the only supportive idea, the function have a slightly different API compared to the rest of the TUC-Bot library.

In order to use any of these functions, include tucbot_additionals/control.h into your code.

Some points you might keep in mind, while programming your own and better version of the controller:

Working with floats is very inefficient - use int16_t or int32_t instead! (There is no floating point unit available on the microcontroller.)
When accessing multi-byte variables (float, int16_t, ...) at the same time, you should guard them!
Interrupt routines should be as short and efficient as possible!

The folowin data packet is published via XBee: "%li %d %d %d %d %d\n"

time[ms]
desired speed [tics/s]
drive level left [%]
drive level right [%]
speed left [tics/s]
speed right [tics/s]

Function Documentation

◆ pid_control_init()

uint8_t pid_control_init	(	float	Kp,
		float	Ki,
		float	Kd,
		int	freq
	)

Activate the control loop. This adds the control loop to the queue which is processed each time a systick interrupt occures.

Parameters

Kp	proportional constant
Ki	integral constant
Kd	differential constant
freq	16-bit integer (1..100) The frequency is measured in Hz. Since the systick is internally used to cyclic call the controller, only multiple intervals of 10ms can be used. Therefore, the frequency should be choosen wisely. E.g. 17, 18, 19 and 20 will all result to an interval of 50ms.

◆ pid_control_Kd()

float pid_control_Kd ( void )

Get differential constant of the PID controller.

◆ pid_control_Ki()

float pid_control_Ki ( void )

Get integral constant of the PID controller.

◆ pid_control_Kp()

float pid_control_Kp ( void )

Get proportional constant of the PID controller.

◆ pid_control_reset()

void pid_control_reset ( void )

Reset the internal variables of the controller.

◆ pid_control_set_Kd()

void pid_control_set_Kd ( float Kd )

Set differential constant of the PID controller.

◆ pid_control_set_Ki()

void pid_control_set_Ki ( float Ki )

Set integral constant of the PID controller.

◆ pid_control_set_Kp()

void pid_control_set_Kp ( float Kp )

Set proportional constant of the PID controller.

◆ pid_control_set_sp()

void pid_control_set_sp ( int16_t v_desired )

Set a new setpoint for the velocity control in tics/s.

◆ pid_control_sp()

int16_t pid_control_sp ( void )

Get the current setpoint for the velocity control in tics/s..

◆ pid_control_stop()

void pid_control_stop ( void )

Deactivate the control loop. This removes the control loop from the queue which is processed each time a systick interrupt occures.

◆ pid_control_use_ramp()

void pid_control_use_ramp ( uint8_t ramp )

If use_ramp is active, the internal setpoint will change smoothly.
The stepsize is set by the constant RAMP.

Macros

Functions