Joint Position Controller. More...

#include <joint_position_controller.h>

Inheritance diagram for velocity_controllers::JointPositionController:

Classes
struct	Commands
	Store position and velocity command in struct to allow easier realtime buffer usage. More...
Public Member Functions
void	getGains (double &p, double &i, double &d, double &i_max, double &i_min)
	Get the PID parameters.
std::string	getJointName ()
	Get the name of the joint this controller uses.
double	getPosition ()
	Get the current position of the joint.
bool	init (hardware_interface::VelocityJointInterface *robot, ros::NodeHandle &n)
	The init function is called to initialize the controller from a non-realtime thread with a pointer to the hardware interface, itself, instead of a pointer to a RobotHW.
	JointPositionController ()
void	printDebug ()
	Print debug info to console.
void	setCommand (double pos_target)
	Give set position of the joint for next update: revolute (angle) and prismatic (position)
void	setCommand (double pos_target, double vel_target)
	Give set position of the joint for next update: revolute (angle) and prismatic (position) Also supports a target velocity.
void	setGains (const double &p, const double &i, const double &d, const double &i_max, const double &i_min)
	Get the PID parameters.
void	starting (const ros::Time &time)
	This is called from within the realtime thread just before the first call to update.
void	update (const ros::Time &time, const ros::Duration &period)
	Issues commands to the joint. Should be called at regular intervals.
	~JointPositionController ()
Public Attributes
realtime_tools::RealtimeBuffer < Commands >	command_
Commands	command_struct_
hardware_interface::JointHandle	joint_
boost::shared_ptr< const urdf::Joint >	joint_urdf_
Private Member Functions
void	enforceJointLimits (double &command)
	Check that the command is within the hard limits of the joint. Checks for joint type first. Sets command to limit if out of bounds.
void	setCommandCB (const std_msgs::Float64ConstPtr &msg)
	Callback from /command subscriber for setpoint.
Private Attributes
boost::scoped_ptr < realtime_tools::RealtimePublisher < control_msgs::JointControllerState > >	controller_state_publisher_
int	loop_count_
control_toolbox::Pid	pid_controller_
ros::Subscriber	sub_command_

Detailed Description

Joint Position Controller.

This class controls positon using a pid loop.

ROS

Parameters:

type	Must be "velocity_controllers::JointPositionController"
joint	Name of the joint to control.
pid	Contains the gains for the PID loop around position. See: control_toolbox::Pid

Subscribes to:

command (std_msgs::Float64) : The joint position to achieve.

Publishes:

state (control_msgs::JointControllerState) : Current state of the controller, including pid error and gains.

Definition at line 85 of file joint_position_controller.h.

Constructor & Destructor Documentation

velocity_controllers::JointPositionController::JointPositionController ( )

Definition at line 49 of file joint_position_controller.cpp.

velocity_controllers::JointPositionController::~JointPositionController ( )

Definition at line 53 of file joint_position_controller.cpp.

Member Function Documentation

void velocity_controllers::JointPositionController::enforceJointLimits ( double & command ) [private]

Check that the command is within the hard limits of the joint. Checks for joint type first. Sets command to limit if out of bounds.

Parameters:

command - the input to test

Definition at line 245 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::getGains	(	double &	p,
		double &	i,
		double &	d,
		double &	i_max,
		double &	i_min
	)

Get the PID parameters.

Definition at line 104 of file joint_position_controller.cpp.

std::string velocity_controllers::JointPositionController::getJointName ( )

Get the name of the joint this controller uses.

Definition at line 114 of file joint_position_controller.cpp.

double velocity_controllers::JointPositionController::getPosition ( )

Get the current position of the joint.

Returns:: current position

Definition at line 119 of file joint_position_controller.cpp.

bool velocity_controllers::JointPositionController::init	(	hardware_interface::VelocityJointInterface *	robot,
		ros::NodeHandle &	n
	)		`[virtual]`

The init function is called to initialize the controller from a non-realtime thread with a pointer to the hardware interface, itself, instead of a pointer to a RobotHW.

Parameters:

robot	The specific hardware interface used by this controller.
n	A NodeHandle in the namespace from which the controller should read its configuration, and where it should set up its ROS interface.

Returns:: True if initialization was successful and the controller is ready to be started.

Reimplemented from controller_interface::Controller< hardware_interface::VelocityJointInterface >.

Definition at line 58 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::printDebug ( )

Print debug info to console.

Definition at line 109 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::setCommand ( double pos_target )

Give set position of the joint for next update: revolute (angle) and prismatic (position)

Parameters:

command

Definition at line 125 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::setCommand	(	double	pos_target,
		double	vel_target
	)

Give set position of the joint for next update: revolute (angle) and prismatic (position) Also supports a target velocity.

Parameters:

pos_target	- position setpoint
vel_target	- velocity setpoint

Definition at line 137 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::setCommandCB ( const std_msgs::Float64ConstPtr & msg ) [private]

Callback from /command subscriber for setpoint.

Definition at line 239 of file joint_position_controller.cpp.

void velocity_controllers::JointPositionController::setGains	(	const double &	p,
		const double &	i,
		const double &	d,
		const double &	i_max,
		const double &	i_min
	)