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Cannot control the joints using gazebo_ros_control plugin

asked 2016-05-30 03:40:04 -0600

wyxf007 gravatar image

Hi, I am modeling a walking robot in URDF with all the joints controlled by gazebo_ros_control plugin. It was made based on rrbot. Everything seems fine when run it in gazebo, and controller topics can be found. While when I want to use rostopic pub /halobject/Rl1_position_controller/command std_msg/Float64 10, the model has no response to it. Besides, when use rostopic echo /halobject/Rl1_position_controller/state to read the joint data, it also shows no response to my command. During the simulation, there is no error information about it, and my pid parameter is set to be 100,0.01,10. Joint state controller publish rate to be 20. The topics when running is as follows:

/clock
/gazebo/link_states
/gazebo/model_states
/gazebo/parameter_descriptions
/gazebo/parameter_updates
/gazebo/set_link_state
/gazebo/set_model_state
/halobject/Ll1_position_controller/command
/halobject/Ll1_position_controller/pid/parameter_descriptions
/halobject/Ll1_position_controller/pid/parameter_updates
/halobject/Ll1_position_controller/state
/halobject/Ll2_position_controller/command
/halobject/Ll2_position_controller/pid/parameter_descriptions
/halobject/Ll2_position_controller/pid/parameter_updates
/halobject/Ll2_position_controller/state
/halobject/Lla1_position_controller/command
/halobject/Lla1_position_controller/pid/parameter_descriptions
/halobject/Lla1_position_controller/pid/parameter_updates
/halobject/Lla1_position_controller/state
/halobject/Ml_position_controller/command
/halobject/Ml_position_controller/pid/parameter_descriptions
/halobject/Ml_position_controller/pid/parameter_updates
/halobject/Ml_position_controller/state
/halobject/Rl1_position_controller/command
/halobject/Rl1_position_controller/pid/parameter_descriptions
/halobject/Rl1_position_controller/pid/parameter_updates
/halobject/Rl1_position_controller/state
/halobject/Rl2_position_controller/command
/halobject/Rl2_position_controller/pid/parameter_descriptions
/halobject/Rl2_position_controller/pid/parameter_updates
/halobject/Rl2_position_controller/state
/halobject/Rla1_position_controller/command
/halobject/Rla1_position_controller/pid/parameter_descriptions
/halobject/Rla1_position_controller/pid/parameter_updates
/halobject/Rla1_position_controller/state
/halobject/joint_states
/rosout
/rosout_agg
/tf
/tf_static

If anyone else met similar problem before? My file is here https://www.dropbox.com/sh/ew8tkluu6jw1p2e/AABILHj-hwEAzYaDBIaiGfSCa?dl=0 first source the devel/setup.bash then roslaunch halobject_gazebo halobject_world.launch it should start working.

Thank you!

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I have the same problem with a different robot..

pap-x gravatar imagepap-x ( 2016-05-31 03:29:13 -0600 )edit

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answered 2016-06-03 05:25:40 -0600

pap-x gravatar image

I managed to get my robot to work. I have some suggestions for you. First when you spawn the urdf in your launch file you have to spawn it with the name of your robot not rrbot because I think gazebo creates the controllers in the robot name namespace. In your urdf you have in every joint "effort=0.0" which is wrong, this variable defines how much torque of the motor goes to the joint. It has to be more than 0 if the joint has to move. That's all I could suggest!

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Thank you! I use URDF PlugIns of Solidworks to generate the URDF. I didn't set the value of torque, that's why it is zero, I will do some changes based on it.

wyxf007 gravatar imagewyxf007 ( 2016-06-03 13:46:32 -0600 )edit

Now it works, the limit is just the problem. I thought the default setting in plugin won't hurt, while ... Thank you!

wyxf007 gravatar imagewyxf007 ( 2016-06-03 14:27:31 -0600 )edit

Hi. Sorry its already late for the question. I am also trying to move the joints of the biped robot. I had already set the effort values and also tuned the pid parameters. Now the robot is not collapsing but when I do 'rostopic pub joint', the joints wont move. Can you help me with this? Thanks in advance.

franklin_selva gravatar imagefranklin_selva ( 2019-01-09 23:25:24 -0600 )edit
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Asked: 2016-05-30 03:40:04 -0600

Seen: 1,811 times

Last updated: Jun 03 '16