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"WARNING: no messages received and simulated time is active. Is /clock being published?" - Force Torque

asked 2018-03-20 23:18:05 -0500

lr101095 gravatar image

updated 2018-03-21 17:40:24 -0500

Running ubuntu 16.04, ROS kinetic, gazebo 7.

Trying to implement a force torque sensor model onto the end-effector of a sawyer robot. Model was successfully implemented, but plugin doesn't publish any data. I get the warning from the question title. Yes, /clock is being published because calling "rostopic echo /clock" will show the simulation clock.

warning occurs when i call "rostopic echo /right_hand_ft_sensor/ft_sensor_topic

I've found solutions where it suggests to call the following: "rosparam set use_sim_time false" and that hasn't fixed anything.

I've also seen solutions where it says to set the update_rate of the sensor to 0 in the robot.urdf. I can't try this solution because my sawyer.urdf does not contain the relevant section in the code where i would can set it the update rate to 0. the sensor package is based on xacro and i just include in the launch file of the sawyer robot.

any suggestions or advice would be much appreciated.

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What command are you running that causes the warning message to be published?

imcmahon gravatar image imcmahon  ( 2018-03-21 09:10:31 -0500 )edit

@imcmahon please see edited post

lr101095 gravatar image lr101095  ( 2018-03-21 17:39:41 -0500 )edit

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answered 2018-03-21 09:20:39 -0500

imcmahon gravatar image

updated 2018-03-21 09:33:50 -0500

(Hopefully) you shouldn't need to implement your own force-torque sensor for Sawyer in Gazebo. The sawyer_gazebo package actually simulates the torque values being experienced by each joint in the arm directly. You can see each of these torques on the topic /robot/joint_states. A force-torque sensor is usually used to measure the force experienced at the end effector of the robot. Part of the simulation is a handy topic that reports all of these joint torques are transformed into the endpoint frame on the /robot/limb/right/endpoint_state topic using the intera_core_msgs/EndpointState message.

The following is the RViz rendering of the effort portion of the /robot/joint_states topic: Sawyer RViz Torques in Gazebo

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i forgot to mention that i'm implementing the ft sensor on the end-effector of sawyer. made the correction in my post.

lr101095 gravatar image lr101095  ( 2018-03-21 17:41:30 -0500 )edit

Ah, I see. I would recommend looking at the endpoint_state topic I mentioned above. It should give you the same data that a FT sensor would give in the endpoint frame.

imcmahon gravatar image imcmahon  ( 2018-03-21 18:06:05 -0500 )edit

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Asked: 2018-03-20 23:18:05 -0500

Seen: 2,804 times

Last updated: Mar 21 '18