control_msgs¶

Message types¶

• control_msgs/JointControllerState
• control_msgs/JointTrajectoryControllerState
• control_msgs/JointTolerance
• control_msgs/GripperCommand

control_msgs/JointControllerState¶

Field:	header (std_msgs/Header) – set_point (float64) – process_value (float64) – process_value_dot (float64) – error (float64) – time_step (float64) – command (float64) – p (float64) – i (float64) – d (float64) – i_clamp (float64) –

Header header
float64 set_point
float64 process_value
float64 process_value_dot
float64 error
float64 time_step
float64 command
float64 p
float64 i
float64 d
float64 i_clamp

control_msgs/JointTrajectoryControllerState¶

Field:	header (std_msgs/Header) – joint_names[] (string) – desired (trajectory_msgs/JointTrajectoryPoint) – actual (trajectory_msgs/JointTrajectoryPoint) – error (trajectory_msgs/JointTrajectoryPoint) –

Header header
string[] joint_names
trajectory_msgs/JointTrajectoryPoint desired
trajectory_msgs/JointTrajectoryPoint actual
trajectory_msgs/JointTrajectoryPoint error  # Redundant, but useful

control_msgs/JointTolerance¶

Field:	name (string) – position (float64) – velocity (float64) – acceleration (float64) –

The tolerances specify the amount the position, velocity, and accelerations can vary from the setpoints. For example, in the case of trajectory control, when the actual position varies beyond (desired position + position tolerance), the trajectory goal may abort.

There are two special values for tolerances:

• 0 - The tolerance is unspecified and will remain at whatever the default is

• -1 - The tolerance is “erased”. If there was a default, the joint will be

  allowed to move without restriction.

# The tolerances specify the amount the position, velocity, and
# accelerations can vary from the setpoints.  For example, in the case
# of trajectory control, when the actual position varies beyond
# (desired position + position tolerance), the trajectory goal may
# abort.
# 
# There are two special values for tolerances:
#  * 0 - The tolerance is unspecified and will remain at whatever the default is
#  * -1 - The tolerance is "erased".  If there was a default, the joint will be
#         allowed to move without restriction.

string name
float64 position  # in radians or meters (for a revolute or prismatic joint, respectively)
float64 velocity  # in rad/sec or m/sec
float64 acceleration  # in rad/sec^2 or m/sec^2

control_msgs/GripperCommand¶

Field:	position (float64) – max_effort (float64) –

float64 position
float64 max_effort

Service types¶

• control_msgs/QueryTrajectoryState
• control_msgs/QueryCalibrationState

control_msgs/QueryTrajectoryState¶

Field (Request):
	time (time) –
Field (Response):
	name[] (string) – position[] (float64) – velocity[] (float64) – acceleration[] (float64) –

time time
---
string[] name
float64[] position
float64[] velocity
float64[] acceleration

control_msgs/QueryCalibrationState¶

Field (Response):
	is_calibrated (bool) –

---
bool is_calibrated

Action types¶

• control_msgs/GripperCommand
• control_msgs/SingleJointPosition
• control_msgs/FollowJointTrajectory
• control_msgs/JointTrajectory
• control_msgs/PointHead

control_msgs/GripperCommand¶

Field (Goal):	command (control_msgs/GripperCommand) –
Field (Result):	position (float64) – effort (float64) – stalled (bool) – reached_goal (bool) –
Field (Feedback):
	position (float64) – effort (float64) – stalled (bool) – reached_goal (bool) –

GripperCommand command
---
float64 position  # The current gripper gap size (in meters)
float64 effort    # The current effort exerted (in Newtons)
bool stalled      # True iff the gripper is exerting max effort and not moving
bool reached_goal # True iff the gripper position has reached the commanded setpoint
---
float64 position  # The current gripper gap size (in meters)
float64 effort    # The current effort exerted (in Newtons)
bool stalled      # True iff the gripper is exerting max effort and not moving
bool reached_goal # True iff the gripper position has reached the commanded setpoint

control_msgs/SingleJointPosition¶

Field (Goal):	position (float64) – min_duration (duration) – max_velocity (float64) –
Field (Feedback):
	header (std_msgs/Header) – position (float64) – velocity (float64) – error (float64) –

float64 position
duration min_duration
float64 max_velocity
---
---
Header header
float64 position
float64 velocity
float64 error

control_msgs/FollowJointTrajectory¶

Field (Goal):	trajectory (trajectory_msgs/JointTrajectory) – path_tolerance[] (control_msgs/JointTolerance) – goal_tolerance[] (control_msgs/JointTolerance) – goal_time_tolerance (duration) –
Field (Result):	error_code (int32) – error_string (string) –
Constant (Result):
	SUCCESSFUL (int32):0 – INVALID_GOAL (int32):-1 – INVALID_JOINTS (int32):-2 – OLD_HEADER_TIMESTAMP (int32):-3 – PATH_TOLERANCE_VIOLATED (int32):-4 – GOAL_TOLERANCE_VIOLATED (int32):-5 –
Field (Feedback):
	header (std_msgs/Header) – joint_names[] (string) – desired (trajectory_msgs/JointTrajectoryPoint) – actual (trajectory_msgs/JointTrajectoryPoint) – error (trajectory_msgs/JointTrajectoryPoint) –

The joint trajectory to follow

# The joint trajectory to follow
trajectory_msgs/JointTrajectory trajectory

# Tolerances for the trajectory.  If the measured joint values fall
# outside the tolerances the trajectory goal is aborted.  Any
# tolerances that are not specified (by being omitted or set to 0) are
# set to the defaults for the action server (often taken from the
# parameter server).

# Tolerances applied to the joints as the trajectory is executed.  If
# violated, the goal aborts with error_code set to
# PATH_TOLERANCE_VIOLATED.
JointTolerance[] path_tolerance

# To report success, the joints must be within goal_tolerance of the
# final trajectory value.  The goal must be achieved by time the
# trajectory ends plus goal_time_tolerance.  (goal_time_tolerance
# allows some leeway in time, so that the trajectory goal can still
# succeed even if the joints reach the goal some time after the
# precise end time of the trajectory).
#
# If the joints are not within goal_tolerance after "trajectory finish
# time" + goal_time_tolerance, the goal aborts with error_code set to
# GOAL_TOLERANCE_VIOLATED
JointTolerance[] goal_tolerance
duration goal_time_tolerance

---
int32 error_code
int32 SUCCESSFUL = 0
int32 INVALID_GOAL = -1
int32 INVALID_JOINTS = -2
int32 OLD_HEADER_TIMESTAMP = -3
int32 PATH_TOLERANCE_VIOLATED = -4
int32 GOAL_TOLERANCE_VIOLATED = -5

# Human readable description of the error code. Contains complementary
# information that is especially useful when execution fails, for instance:
# - INVALID_GOAL: The reason for the invalid goal (e.g., the requested
#   trajectory is in the past).
# - INVALID_JOINTS: The mismatch between the expected controller joints
#   and those provided in the goal.
# - PATH_TOLERANCE_VIOLATED and GOAL_TOLERANCE_VIOLATED: Which joint
#   violated which tolerance, and by how much.
string error_string

---
Header header
string[] joint_names
trajectory_msgs/JointTrajectoryPoint desired
trajectory_msgs/JointTrajectoryPoint actual
trajectory_msgs/JointTrajectoryPoint error

control_msgs/JointTrajectory¶

Field (Goal):	trajectory (trajectory_msgs/JointTrajectory) –

trajectory_msgs/JointTrajectory trajectory
---
---

control_msgs/PointHead¶

Field (Goal):	target (geometry_msgs/PointStamped) – pointing_axis (geometry_msgs/Vector3) – pointing_frame (string) – min_duration (duration) – max_velocity (float64) –
Field (Feedback):
	pointing_angle_error (float64) –

geometry_msgs/PointStamped target
geometry_msgs/Vector3 pointing_axis
string pointing_frame
duration min_duration
float64 max_velocity
---
---
float64 pointing_angle_error