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TF question about robot arm

asked 2014-04-25 20:21:36 -0500

Yantian_Zha gravatar image

Hi all, I have Groovy, a pincher arm, and turtlebot. I got success in "rosrun tf tf_echo base_link gripper_link", which shown TF data. But these data never change in accordance with time, though I changed the pose of gripper sometimes. Is it problematic? In my guess TF data should change and tell me the real-time pose of gripper. I don't know whether it's problem in URDF model issue(maybe URDF fails to connect with arm?). Thanks so much!

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answered 2014-04-27 14:35:41 -0500

Yantian_Zha gravatar image

I solved it. In launch file the joint publisher sentence should be commented out, because it's only used for fake robot.

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Yantian I too have ROS Groovy Turtlebot(create) & Dynamax Pincher Arm. I'm curious what packages u installed to control the arm? I did install the groovy dynamax packages but I understand older (pre Groovy) simple arm packages are depreciated and being updated to Moveit!

RobotRoss gravatar image RobotRoss  ( 2014-05-09 07:37:45 -0500 )edit

I'm actually using phantomx pincher arm, and I'm not sure now that it's the same with U(but maybe). I'm now just using arbotix grooy 4.0 package(the driver) to control the arm, because other package including simple_arms and turtlebot_arms were gone, as what U said. But I'm also truing to fix then.

Yantian_Zha gravatar image Yantian_Zha  ( 2014-05-09 13:07:23 -0500 )edit

Also, the arm.launch in turtlebot_arm_bringup package can be used to start the arbotix driver.

Yantian_Zha gravatar image Yantian_Zha  ( 2014-05-09 13:08:36 -0500 )edit

answered 2014-04-25 22:56:37 -0500

Yes, the transform between base_link and gripper_link is expected to change when you move the arm. You´ll have to post more information (for example the actual output of rosrun tf tf_echo base_link gripper_link or and/or your URDF model) for people to be able to give a more detailed answer.

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I changed the _robot.launch: add a "include file..." sentence, which mount an arm to turtlebot, and a sentence of "joint_state_publisher", and nothing is wrong if tested by "view_robot.launch". In rviz I can see the right model, right robot states which including TF.

Yantian_Zha gravatar image Yantian_Zha  ( 2014-04-26 12:40:43 -0500 )edit

Then I edit the arm_bring.launch, which launch two nodes: arbotix_driver node and gripper_controller node, then I can see the arbotix was connected after roslaunching it. I guess there should be a connection between this and edited published joint states based on urdf. Thanks!

Yantian_Zha gravatar image Yantian_Zha  ( 2014-04-26 12:45:04 -0500 )edit

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Asked: 2014-04-25 20:21:36 -0500

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Last updated: Apr 27 '14