ArtBrakeModel Class Reference

#include <model_brake.h>

Public Member Functions
	ArtBrakeModel (float init_pos)
int	interpret (const char string, char status, int nbytes)
	~ArtBrakeModel ()
Private Member Functions
double	getAccel (double direction)
	Get acceleration constant from direction of movement (-, 0, +).
void	move (double start, double finish)
double	plan (double dx)
void	update (void)
void	update_sensors (float position)
Private Attributes
double	a_
double	actuator_accel_
double	actuator_max_vel_
Animatics *	am_
float	brake_position_
int	digital_potentiometer_
int	digital_pressure_
int	encoder_goal_
double	last_update_time_
ros::NodeHandle	node_
ActuatorPlan	plan_
int	sim_encoder_
int	sim_status_
double	v_
double	x_

Detailed Description

Definition at line 107 of file model_brake.h.

Constructor & Destructor Documentation

ArtBrakeModel::ArtBrakeModel ( float init_pos )

Constructor

Definition at line 30 of file model_brake.cc.

ArtBrakeModel::~ArtBrakeModel ( )

Definition at line 60 of file model_brake.cc.

Member Function Documentation

double ArtBrakeModel::getAccel ( double direction ) [inline, private]

Get acceleration constant from direction of movement (-, 0, +).

Definition at line 146 of file model_brake.h.

int ArtBrakeModel::interpret	(	const char *	string,
		char *	status,
		int	nbytes
	)

Interpret actuator command and return response.

interpret brake command and return response

Only certain commands require interpretation. All others are just accepted, acknowledged, and ignored.

Definition at line 70 of file model_brake.cc.

void ArtBrakeModel::move	(	double	start,
		double	finish
	)			`[private]`

Move simulated actuator.

Parameters:

	start	time for simulation
	finish	time.

The Animatics Smart Motor provides a constant acceleration and deceleration up to a maximum velocity.

Definition at line 154 of file model_brake.cc.

double ArtBrakeModel::plan ( double dx ) [private]

Plan actuator relative move.

Parameters:

dx

= encoder ticks to move.

Returns:: time (in seconds) required to get there.

This calculation assumes a triangular velocity profile with constant acceleration |a|, applied first in one direction, then in the other.

Erase any previous plan, then move the actuator in two steps:

(1) accelerate in direction requested; (2) decelerate to zero velocity

The real device supports a trapezoidal velocity profile with a maximum velocity (actuator_max_vel_). Since it takes a long time to reach actuator_max_vel_, this model ignores that detail, which does not seem to matter much in practice.

Definition at line 206 of file model_brake.cc.

void ArtBrakeModel::update ( void ) [private]

update brake actuator model for start of cycle

Definition at line 243 of file model_brake.cc.

void ArtBrakeModel::update_sensors ( float position ) [private]

Definition at line 285 of file model_brake.cc.