A controller for driving a differential drive base to a pose goal or along a path specified by multiple poses. More...

#include <diff_drive_pose_controller_ros.hpp>

Inheritance diagram for yocs::DiffDrivePoseControllerROS:

Public Member Functions
	DiffDrivePoseControllerROS (ros::NodeHandle &nh, std::string &name)

bool	init ()
	Set-up necessary publishers/subscribers and variables. More...

void	spinOnce ()
	Calculates velocity commands to move the diff-drive base to the (next) pose goal. More...

virtual	~DiffDrivePoseControllerROS ()

Public Member Functions inherited from yocs::DiffDrivePoseController
	DiffDrivePoseController (std::string name, double v_max, double w_max, double dist_thres=0.01, double orient_thres=0.02, double dist_eps=0.01 0.2, double orient_eps=0.02 0.2, double orientation_gain=0.3, double k_1=1.0, double k_2=3.0, double beta=0.4, double lambda=2.0, double v_min=0.01, double v_min_movement=0.01, double w_min_movement=0.01)

virtual void	getControlOutput (double &v, double &w)
	Get controller result / output after spinning. More...

void	setCurrentLimits (double v_min, double w_min, double v_max, double w_max)

virtual void	setInput (double distance_to_goal, double delta, double theta)
	Set input of controller. Should be called before each spinOnce. More...

void	setVerbosity (const bool &verbose)

virtual bool	step ()
	Execute one controller step. More...

virtual	~DiffDrivePoseController ()

Public Member Functions inherited from yocs::Controller
	Controller ()

bool	disable ()

bool	enable ()

bool	getState ()

virtual void	spin ()

virtual	~Controller ()

Private Member Functions
void	controlMaxVelCB (const std_msgs::Float32ConstPtr msg)
	Callback for updating the controller's maximum linear control velocity. More...

void	disableCB (const std_msgs::EmptyConstPtr msg)
	Callback for disabling the controler. More...

void	enableCB (const std_msgs::StringConstPtr msg)
	Callback for enabling the controler. More...

bool	getPoseDiff ()
	Determines the pose difference in polar coordinates. More...

virtual void	onGoalReached ()
	Publishes goal is reached message. More...

void	setControlOutput ()
	Calculates the controller output based on the current pose difference. More...

Private Attributes
std::string	base_frame_name_
	frame name of the base More...

ros::Publisher	command_velocity_publisher_
	publisher for sending out base velocity commands More...

ros::Subscriber	control_velocity_subscriber_
	subscriber for setting the controller's linear velocity More...

ros::Subscriber	disable_controller_subscriber_
	subscriber for disabling the controller More...

ros::Subscriber	enable_controller_subscriber_
	subscriber for enabling the controller More...

std::string	goal_frame_name_
	frame name of the goal (pose) More...

std::string	name_

ros::NodeHandle	nh_

ros::Publisher	pose_reached_publisher_
	publishes the status of the goal pose tracking More...

tf::StampedTransform	tf_goal_pose_rel_
	transform for the goal pose relative to the base pose More...

tf::TransformListener	tf_listener_
	tf used to get goal pose relative to the base pose More...

Additional Inherited Members
Protected Member Functions inherited from yocs::DiffDrivePoseController
virtual void	calculateControls ()
	Calculates the controls with the set variables (speed, goal etc.) More...

virtual void	controlOrientation (double angle_difference)

virtual void	controlPose ()

virtual double	enforceMinMax (double &value, double min, double max)
	Enforce value to be between min and max. More...

virtual double	enforceMinVelocity (double value, double min)
	Enforce the minimum velocity. More...

Protected Attributes inherited from yocs::DiffDrivePoseController
double	beta_

double	cur_
	path to goal curvature More...

double	delta_
	current heading of the base [rad] More...

double	dist_eps_
	Error in distance above which pose is considered different. More...

double	dist_thres_
	lower bound for the distance (v = 0) More...

double	k_1_
	constant factor determining the ratio of the rate of change in theta to the rate of change in r More...

double	k_2_
	constant factor applied to the heading error feedback More...

double	lambda_

std::string	name_

double	orient_eps_
	Error in orientation above which pose is considered different. More...

double	orient_thres_
	lower bound for the orientation (w = 0) More...

double	orientation_gain_
	p gain for angle controller More...

bool	pose_reached_
	True, if pose has been reached (v == 0, w == 0) More...

double	r_
	distance to pose goal [m] More...

double	theta_
	direction of the pose goal [rad] More...

double	v_
	linear base velocity [m/s] More...

double	v_max_
	maximum linear base velocity [m/s] More...

double	v_min_
	(current) minimum linear base velocity [m/s] More...

double	v_min_movement_
	minimum linear base velocity at which we still move [m/s] More...

bool	verbose_
	Enable or disable ros messages. More...

double	w_
	angular base velocity [rad/s] More...

double	w_max_
	maximum angular base velocity [rad/s] More...

double	w_min_
	(current) minimum angular base velocity [rad/s] More...

double	w_min_movement_
	minimum angular base velocity at which we still move [rad/s] More...

Detailed Description

A controller for driving a differential drive base to a pose goal or along a path specified by multiple poses.

This controller implements a control law drives a differental drive base towards a planar pose goal, i.e. 2D position (x,y) + 1D orientation (theta). It also allows path following by specifying multiple pose goals. The control law contains a transition strategy, which insures that the base moves through each pose and transitions smoothly to the next pose goal.

This controller is an implementation of control law based on the following work: {DBLP:conf/icra/ParkK11, author = {Jong Jin Park and Benjamin Kuipers}, title = {A smooth control law for graceful motion of differential wheeled mobile robots in 2D environment}, booktitle = {ICRA}, year = {2011}, pages = {4896-4902}, ee = {http://dx.doi.org/10.1109/ICRA.2011.5980167}, crossref = {DBLP:conf/icra/2011}, bibsource = {DBLP, http://dblp.uni-trier.de} }

This controller can be enabled/disabled.

Definition at line 76 of file diff_drive_pose_controller_ros.hpp.