CartesianPoseController

A controller which drives a Cartesian pose of a target_frame toward a target pose given relative to a specified base_frame.

NOTE: This controller requires a controller_manager update_rate of at least 500Hz.

Usage

Create an entry in your controllers.yaml and add it to your launch file infrastructure. Set base_frame and target_frame accordingly. Do not activate on startup.
Activate the controller -> It claims the position (and, if command_velocities is true, also velocity) interfaces of all joints between base_frame and target_frame.
Publish a target pose -> The end effector should now move towards it, respecting the configured cartesian velocity/acceleration limits.

Configuration example

cartesian_pose_controller:
  ros__parameters:
    base_frame: "base_link"
    target_frame: "flange"
    command_velocities: true
    limits:
      velocity:
        linear: 1.0
        angular: 6.283
      acceleration:
        linear: 2.0
        angular: 12.566

Interaction

Publish target poses relative to base_frame on /<topic_prefix>/<target_frame>/<target_topic_suffix> (geometry_msgs/msg/PoseStamped).

If topic_pub_frequency is greater than zero, the current target pose/twist relative to base_frame are published on /<topic_prefix>/<target_frame>/pose and /<topic_prefix>/<target_frame>/twist.

topic_prefix defaults to the controller name if left empty.

Parameters

Name	Description	Default	Bounds
`base_frame`	Name of the base frame	`base_link`	-
`target_frame`	Name of the target frame to be controlled	-	may not be empty
`target_filter`	Exponential target filter time constant [s]	0.1	[0.0, 10.0]
`command_velocities`	If true, also claims and commands the joints’ velocity interface	true	-
`limits.velocity.linear`	Maximum linear velocity [m/s]	1.0	[0.0, 10.0]
`limits.velocity.angular`	Maximum angular velocity [rad/s]	6.283	[0.0, 62.83]
`limits.acceleration.linear`	Maximum linear acceleration [m/s^2]	2.0	[0.0, 100.0]
`limits.acceleration.angular`	Maximum angular acceleration [rad/s^2]	12.466	[0.0, 628.3]
`topic_prefix`	Prefix to all topics. If empty, the controller name is used	-	-
`target_topic_suffix`	Suffix added to the target frame topic for receiving control inputs	`target`	-
`topic_pub_frequency`	Frequency of the published end effector pose/twist topics. Zero disables publishing	10.0	[0.0, 1000.0]

Debug parameters

Name	Description	Default	Bounds
`enable_introspection`	Enable ros2control introspection for internal state monitoring	false	-
`dry_run`	If true, the controller will not claim command interfaces	false	-

Expert-only parameters

Name	Description	Default	Bounds
`velocity_feedback`	Filter weight for the joint velocity feedback. 0 disables it	0.001	[0.0, 1.0]
`motion_horizon`	Time horizon [s] used to scale the IK solver’s joint displacement variable	0.01	[0.001, 1.0]
`ik_damping`	Weight to dampen all joint motions and stabilize the IK solution	0.01	[0.000001, 1.0]
`ik_meter_to_revolution_error_correlation`	Correlation between linear (one meter) and angular (one revolution) errors in the IK solver	25.0	[1.0, 100.0]
`ik_precision`	Precision of the inverse kinematics solver	0.0001	[0.000001, 0.1]
`ik_max_iterations`	Maximum number of iterations for the inverse kinematics solver	10	[3, 30]

Notes

Every joint not on the direct path between base_frame and target_frame is treated as fixed.
A correctly configured URDF is needed (correct frame names and joint types).
This controller only support hinge (revolute) joints to be controlled.

References

Pinocchio library