roboren's profile - activity

Hi all,

I'm trying to control pr2's head (i.e., moving up and down, left and right) in simulation, but couldn't get it working. To this effort, I start with playing with controlling right gripper as in the tutorial ( http://www.ros.org/wiki/pr2_simulator... ). However, publishing a command does not seem to work (?!). It did not change anything. Actually I do not know what to expect..

Can anyone give me some directions of controlling pr2's head? Thanks a lot.

All,

I'm using pr2_teleop to move pr2 in gazebo simulator. The robot moves fine in gazabo, but the movement does not show up in RViz. Are these two not synchronized? Or these two serve different purposes?

Thank you!

Hi all,

I just started to play with ROS and gazebo. I've went through the gazebo tutorial and wanted to move to pr2_gazebo tutorial. But now, I'm have problems of installing pr2_gazebo.

First, I checked out the pr2_simulator at ( https://code.ros.org/svn/wg-ros-pkg/s... ) Then, I tried "rosdep install pr2_gazebo", but got a bunch of error messages (e.g., Failed to find stack for package [joint_trajectory_action]).

Where should I get those dependency packages? I appreciate any pointers to get me started with pr2 simulator.

Thanks!

Yes, it is definitely possible.

You just define the service in any package (e.g. package A) and make package A a dependency for the packages using the service. Of course, a package can use its own service, too.

This question is the same in principle (just for messages):

Hi all, The tutorial gives an example of communication between nodes in the same package. Is it possible to use service to communicate between nodes in different package? Does that mean I should load two manifests?

Thanks!

For moving the gripper, if you're running diamondback and newer, did you follow this link?

For moving the head, check out this tutorial.

if you want to control the head of the PR2 you should send goals to the pr2_head_action (http://www.ros.org/wiki/pr2_head_action). The pr2_controllers and pr2_common_actions packages many of the basic actions available for controlling the PR2

Do you have a transform from the world or map frame to your robot? In the tutorial I looked at it appears that robot localisation is performed by the fake localisation package. When I tried it out it looks like the localisation package is not generating transforms from the world to the robot frame.

I ended up with manually download all missing dependency packages, and it seems working now.

The parameter is only stored in the parameter server (that lives with roscore). When you change it the program does not necessarily know about this and will not react to a change.

The clear service call just triggers the program to redraw and in the process acquire the current (newly set) parameter.

For parameter changes that should take effect immediately there is dynamic_reconfigure.

I'm going through this tutorial ( http://www.ros.org/wiki/ROS/Tutorials... ) and am unclear about one thing. After setting a new parameter (rosparam set background_r 150), why we need to call clear service (rosservice call clear) to make the change take effect?

How do they work? Thanks!