Control your manipulator in any given frame, using only Twist messages.
twist_jogger lets you jog the end-effector of your manipulator with Twist
messages.
Clone and install
twist_jogger_demo to
your workspace. Requirements for running this demo are:
universal_robotmofpymofpy_demo- a PS4 controller (not necessary, but you'll need to change the
configurations in
mofpyif you're using some other joypads)
If you have your own ROS node for publishing TwistStamped to jog
manipulators, feel free to use that.
$ roslaunch twist_jogger_demo ur5.launch
This will bring up Gazebo with the UR5 manipulator loaded. You can control the
end-effector in the world frame as follows (if you're using a PS4 controller
with mofpy):
- X: left vertical stick
- Y: left horizontal stick
- Z: L2, R2
- pitch: right vertical stick
- roll: right horizontal stick
- yaw: L1, R1
Here are the features of twist_jogger that you might like.
The demo let you control the end-effector in the world frame. If you want to
control the end-effector in the end-effector frame (this is useful when you're
doing teleop through a camera mounted on the end-effector), simply change the
frame_id of the twist messages that are being sent to twist_jogger. This
also implies that you can dynamically change the frame of command without
restarting the node by simply modifying the value in frame_id.
twist_jogger enables stable execution of the commanded movement by taking
into account the fluctuations in the current joint values sent from the
motors. It does this by keeping the "ideal" state of the joints and commanding
the movements as if the previous commands were perfectly executed.
We use twist_jogger on our 6DOF manipulator and have found that it works
stably both on the simulator and on the actual robot.
twist_jogger uses the /compute_ik and /compute_fk services provided by
MoveIt! You can use twist_jogger on a 6DOF manipulator as well as 7DOF. You
can also test out different inverse kinematics solver, and you can even use
your own solver using IKFast.
In order to use twist_jogger on your robot, you'll need to make your robot
compatible with MoveIt! (more specifically, have the /compute_ik and
/compute_fk services available).
MIT
Naoki Mizuno (mizuno.naoki@rm.is.tohoku.ac.jp)