tadityasrinivas's profile - activity

Could you please describe how to?

I am working with the turtlebot simulator. I have subscribed to the topic /Odometry to read the message on it. I compute the difference between the location in this message and the ground truth location of the robot. I subscribe to the /gazebo/model_states topic to obtain the ground truth location (the "mobile_base" component of the message).

This is the plot of the difference (2D euclidean distance) between the Odometry message and ground truth location: (the sample number increases linearly with time, so the x-axis is proportional to simulation time)

Are there parameters that can be tweaked to reduce this level of accuracy? The problem is that the odometry seems to be accurate within a few centimeters, which is unrealistic. This limits what we can study using the simulated model.

I tried to see if this command would work but it did not.

roslaunch turtlebot_gazebo turtlebot_empty_world.launch gui:=false

Is there an argument that can be used to disable the GUI for turtlebot simulator in Gazebo?

Is there a way to automate pre-determined movement (say around the periphery of the room 20 times) of the turtlebot in the turtlebot simulator? Basically, I'm wondering if there is a way to circumvent having to manually move the simulated robot around using teleop?

I was wondering if there is a way to know the accuracy of the map built using gmapping, in the turtlebot simulator. Also, how to use custom maps for the simulation?

Resolved the problem. The issue was with the graphics driver. Installing proprietary ATI drivers resolved it.

I am running ROS Hydro on Ubuntu 13.04, with kernel 3.8.0-35-generic. My graphics card info: ATI Seymour [Radeon HD 6400M/7400M Series], and I am using the Radeon driver.

I get an error while trying to run the following command from the turtlebot_simulator tutorial:

roslaunch turtlebot_gazebo turtlebot_playground.launch

(I get a similar error while trying to run "roslaunch turtlebot_gazebo turtlebot_empty_world.launch" also)

This is what I get in the terminal window:

process[cmd_vel_mux-6]: started with pid [13821] process[bumper2pointcloud-7]: started with pid [13840] Msg Waiting for master.process[robot_state_publisher-8]: started with pid [13859] Msg Waiting for master Msg Connected to gazebo master @ http:// 127.0.0.1:11345 Msg Publicized address: 10.227.80.208 process[laserscan_nodelet_manager-9]: started with pid [13920] process[depthimage_to_laserscan-10]: started with pid [13926] Floating point exception (core dumped)

[gazebo-2] process has died [pid 13782, exit code 136, cmd /opt/ros/hydro/lib/gazebo_ros/gzserver /opt/ros/hydro/share/turtlebot_gazebo/worlds/playground.world __name:=gazebo __log:=/home/fastslam/.ros/log/cf107f7c-020f-11e4-bfba-e4115b24feb2/gazebo-2.log]. log file: /home/fastslam/.ros/log/cf107f7c-020f-11e4-bfba-e4115b24feb2/gazebo-2*.log

.............................

Error [ConnectionManager.cc:116] Failed to connect to master in 30 seconds.

[gazebo_gui-3] process has died [pid 13787, exit code 255, cmd /opt/ros/hydro/lib/gazebo_ros/gzclient __name:=gazebo_gui __log:=/home/fastslam/.ros/log/cf107f7c-020f-11e4-bfba-e4115b24feb2/gazebo_gui-3.log]. log file: /home/fastslam/.ros/log/cf107f7c-020f-11e4-bfba-e4115b24feb2/gazebo_gui-3*.log