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I'm trying to simulate a door in gazebo but the revolute joint does not seem to work. Could someone take a look at my urdf file and see what might be possibly wrong with it

<robot name="door2">
  <link name="wall">
    <inertial>
      <origin xyz="0 0 1.2" /> 
      <mass value="100.0" />
      <inertia  ixx="1.0" ixy="0"  ixz="0"  iyy="1.0"  iyz="0"  izz="1.0" />
    </inertial>
    <visual>
      <origin xyz="0 0 1.2"/>
      <geometry>
        <box size="0.2 2.4 2.4" />
      </geometry>
    </visual>
    <collision>
      <origin xyz="0 0 1.2"/>
      <geometry>
        <box size="0.2 2.4 2.4" />
      </geometry>
    </collision>
  </link>

  <link name="door">
    <inertial>
      <origin xyz="-0.1 0.6 0" /> 
      <mass value="1.0" />
      <inertia  ixx="1.0" ixy="0"  ixz="0"  iyy="1.0"  iyz="0"  izz="1.0" />
    </inertial>
    <visual>
      <origin xyz="-0.1 0.6 0"/>
      <geometry>
        <box size="0.2 1.2 2.4" />
      </geometry>
    </visual>
    <collision>
      <origin xyz="-0.1 0.6 0"/>
      <geometry>
        <box size="0.2 1.2 2.4" />
      </geometry>
    </collision>
  </link>

  <joint name="hinge" type="revolute">
    <limit upper="0" lower="-1.57" velocity="10" effort="1"/>
    <origin xyz="0.1 1.2 1.2"/>
    <axis xyz="0 0 1" />
    <parent link="wall"/>
    <child link="door"/>
  </joint>   

  <gazebo reference="wall">
    <material>Gazebo/Blue</material>
    <static>true</static>
  </gazebo>
</robot>

This is the link the video I took http://www.youtube.com/watch?v=iCwonqFniqA&feature=youtu.be

I'm running Fuerte, Ubuntu 12.04

Thank you

EDIT: I tried a second time but this time with an extra block to prevent the thing from toppling: http://www.youtube.com/watch?v=l3gPdSxkyCU&feature=youtu.be The door managed to open but with much difficulty, have to move pr2 very slowly. Does anyone know how to make the joint more smooth?

*my velocity and effort for the revolute joint was 1000 and 10000 respectively for the second video if that makes any difference

Hi, I'm wondering if there's any way to adjust the speed of turtlebot. It's moving too fast for my preference.

I'm using a logitech dual action game pad. I can move it perfectly fine when I press button 5 and the arrow keys, except that the speed is really fast and it gets jerky when I press and let go.

Is there any way to get the right joystick of the game pad to control turtlebot. It seems that the right joystick is able to vary its speed depending on how far you move it. Otherwise, I would be happy if someone could teach me at least how to reduce the maximum speed.

Thank you.

When I type "roslaunch turtlebot_calibration calibrate.launch", the terminal shows

[INFO] [WallTime: 1308820084.864965] Estimating imu drift
[INFO] [WallTime: 1308820085.165909] Still waiting for imu
[INFO] [WallTime: 1308820085.466922] Still waiting for imu
[INFO] [WallTime: 1308820085.767989] Still waiting for imu

Eariler on, it showed

[INFO] [WallTime: 1308820084.864965] Estimating imu drift
[INFO] [WallTime: 1308820085.165909] Still waiting for scan
[INFO] [WallTime: 1308820085.466922] Still waiting for scan
[INFO] [WallTime: 1308820085.767989] Still waiting for scan

Does anybody know what these two messages might suggest? I can't understand the code.

Extra info:

-Using a bumblebee2 camera instead of a kinect

-I am using a MicroStrain 3DM-GX2 IMU for turtlebot, I changed the frame_id to gyro_link and the remapped the topic "imu/data" robot_pose_ekf subscribes to to "bumblebee2/bumblebee2/imu/data" so that the imu messages can reach robot_pose_ekf. Despite doing this, I'm not sure if the gyro is working properly as I still get "Bad Gyro Calibration" under diagnosis

Let me know if you require and extra information, I'm not too sure what is relevant. Thanks in advance!

Hi, I'm quite new to vslam and I was wondering if anyone who could help me with this problem. When I try to get live data using a bumblebee2 camera and rviz, the blue lines get all broken and scattered in weird places. like this:

I suspect the following error message below(it was reported in my rviz window) will show what is responsible for this, but I cannot interpret where the error is. Thanks for the help.

[ERROR] [1306481857.228246721]: TF_NAN_INPUT: Ignoring transform for child_frame_id "/visual_odom" from authority "/bumblebee2/stereo_vslam_node" because of a nan value in the transform (nan nan nan) (-nan nan nan -nan)

I'm trying to set up turtlebot but I'm using a bumblebee camera instead of a kinect. I was wondering if anyone has done this before and how to go about doing it.

So far what I have done is commenting out the kinect node in robot.launch and adding a bumblebee node in there which looks like this

  <!-- Bumblebee2 -->
  <node pkg="bumblebee2" type="bumblebee2" name="bumblebee2"
    output="screen" respawn="true">
    <param name="video_mode" value="FORMAT7_3" />
    <param name="fps" value="15" />
    <param name="gain" value="auto" />  
    <param name="brightness" value="auto" />
    <param name="whitebalance" value="auto" /> 
    <param name="shutter" value="auto" />   
    <param name="bayer_pattern" value="BGGR" /> 
    <param name="bayer_method" value="NONE" /> 
  </node>
  <env name="ROS_NAMESPACE" value="bumblebee2" />
  <node pkg="stereo_image_proc" type="stereo_image_proc" name="stereo_image_proc" />

When I start turtlebot, I will get a Bad Gyro Callibration under Sensors Error in Diagnostics from the turtlebot dashboard. Another anomaly I observed is that [kinect_breaker_enabler-8] process has finished cleanly in the terminal where I'm running robot.launch (Well, I did comment out the entire kinect node so this might happen but would this lead to any problems? and how do you solve it?) Logfile attached:kinect_breaker_enabler-8.log.jpg(change .jpg to .log after download, they won't let me upload log files)

I'm still quite new to this and I do not understand how openni is used in turtlebot(it seems to appear several times in the launch file, so I'm not sure if changing the camera would require me to reconfigure some things in openni)

I would be really grateful to anyone who could help me with this.

I'm in the midst of trying to set up turtlebot and I have encountered this problem.

When I type "roslaunch turtlebot_bringup robot.launch" on my laptop, the following message appears

Unable to contact my own server at [http://10.217.252.66:58698/].
This usually means that the network is not configured properly.

I tried pinging myself and it works. Any ideas what might be wrong? Thanks

Hi, I understand from here that you can use the Jacobian function from the KDL library to calculate a the torque to input for a desired force at the tip. i.e. Torque = Jac(j,i)*Force

However, does anyone know a way to do the opposite, to measure the actual force exerted at the end tip by reading the respective measured joint torques. i.e. Measured Force = [some function?]*measured torque at joints.

I tried using the pr2_mechanism_model::JointState to get the measured effort of each joint and use back the Jacobian Transform to get the measured force,

     for (unsigned int i = 0 ; i < 6 ; i++)
  {
    F_measured_(i) = 0;
    for (unsigned int j = 0 ; j < kdl_chain_.getNrOfJoints() ; j++)
      F_measured_ += J_(i,j) * tau_measured_(j);
  }

However, when I can't compile it as the type for the JointState's measured force(double) is different from KDL::Wrench.

In member function ‘virtual void my_controller_ns::MyCartControllerClass::update()’:
  /home/c/fuerte_workspace/sandbox/my_controller_pkg/src/my_cart_controller_file.cpp:112:47: error: no match for ‘operator+=’ in ‘((my_controller_ns::MyCartControllerClass*)this)->my_controller_ns::MyCartControllerClass::F_measured_ += (((my_controller_ns::MyCartControllerClass*)this)->my_controller_ns::MyCartControllerClass::J_.KDL::Jacobian::operator()(i, j) * ((my_controller_ns::MyCartControllerClass*)this)->my_controller_ns::MyCartControllerClass::tau_measured_.KDL::JntArray::operator()(j, 0u))’
  /home/c/fuerte_workspace/sandbox/my_controller_pkg/src/my_cart_controller_file.cpp:112:47: note: candidate is:
  /opt/ros/fuerte/stacks/orocos_kinematics_dynamics/orocos_kdl/install_dir/include/kdl/frames.inl:209:9: note: KDL::Wrench& KDL::Wrench::operator+=(const KDL::Wrench&)
  /opt/ros/fuerte/stacks/orocos_kinematics_dynamics/orocos_kdl/install_dir/include/kdl/frames.inl:209:9: note:   no known conversion for argument 1 from ‘double’ to ‘const KDL::Wrench&’

Can anyone advise me on how do I go about measuring the force of the tip of pr2's arm using the Jacobian function in KDL? Thank you in advance.

EDIT: Thanks Peter, I appreciate any help as I am not very familiar with coding or robotics. Anyway, I realised I made a very silly mistake. The code should be

  for (unsigned int i = 0 ; i < 6 ; i++)
  {
    F_measured_(i) = 0;
    for (unsigned int j = 0 ; j < kdl_chain_.getNrOfJoints() ; j++)
      F_measured_(i) += J_(i,j) * tau_measured_(j);
  }

I forgot the I wrote "F_measured_" instead of "F_measured_(i)" earlier. It can compile now but not sure if it actually works. Will let you know my results afterwards.

I have been reading the various packages that pr2 arm controls uses.

1)http://www.ros.org/wiki/pr2_mechanism_model

2)http://www.ros.org/wiki/pr2_mechanism/Tutorials/Coding%20a%20realtime%20Cartesian%20controller%20with%20KDL

3)http://ros.org/wiki/ee_cart_imped_control#

The API from the first link shows that you can get the measured force of the joint.

However, I can't find any of such members in the 2nd link(or in the KDL library). And from the 3rd link, it says that PR2 don't have force sensors on its joints.

Why do they contradict each other? Could someone clarify with me on this? Thank you in advance. :)

Also, if PR2 joints indeed cannot sense the force/torque on the joint. May I know what does "effort" mean in joint_states_listener Thanks!

EDIT: I'm running simulation on Gazebo if that makes any difference

I'm trying to build a door model but I can't seem to get the coding for revolute joints right. the "base_link" is the wall and "door" is the door.

My code "door.xml" is here

<?xml version="1.0"?>
<robot name="door">
  <link name="base_link">
    <visual>
      <geometry>
        <box size="0.6 0.05 0.6"/>
      </geometry>
      <origin rpy="0 0 0" xyz="0 0 0.3"/>
      <material name="white">
        <color rgba="1 1 1 1"/>
      </material>
    </visual>
    <!--<inertia  ixx="1.0" ixy="0.0"  ixz="0.0"  iyy="100.0"  iyz="0.0"  izz="1.0" />
    </inertia>-->
  </link>

  <link name="door">
    <visual>
      <geometry>
        <box size="0.3 0.05 0.6"/>
      </geometry>
      <origin rpy="0 0 0" xyz="0.15 -0.025 0"/>
    </visual>
  </link>

  <joint name="hinge" type="revolute">
    <limit upper="0" lower="-1.57"velocity="10" effort="10"/>
    <origin xyz="0.3 0.025 .3"/>
    <axis xyz="0 0 1" />
    <parent link="base_link"/>
    <child link="door"/>
  </joint> 
</robot>

I yield the following error

Traceback (most recent call last):
  File "/opt/ros/fuerte/stacks/robot_model_visualization/joint_state_publisher/joint_state_publisher", line 202, in <module>
    jsp = JointStatePublisher()
  File "/opt/ros/fuerte/stacks/robot_model_visualization/joint_state_publisher/joint_state_publisher", line 25, in __init__
    robot = xml.dom.minidom.parseString(description).getElementsByTagName('robot')[0]
  File "/usr/lib/python2.7/xml/dom/minidom.py", line 1930, in parseString
    return expatbuilder.parseString(string)
  File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 940, in parseString
    return builder.parseString(string)
  File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 223, in parseString
    parser.Parse(string, True)
xml.parsers.expat.ExpatError: not well-formed (invalid token): line 47, column 34

Here's a picture of how it looks like on rviz when I run roslaunch urdf_tutorial display.launch model:=door.xml door.png

The visualization on rviz works perfectly find when I use continuous or fixed joints. So I'm not sure whether it is due to my code or some python related script. I'm running on Ubuntu 12.04, Fuerte.

Thanks!

Hi, I'm currently trying to do this tutorial http://gazebosim.org/wiki/tutorials/plugins/simple_world

but at when I compile the code, 'cmake' works fine but 'make' produces the following error

/home/u0905937/fuerte_workspace/sandbox/gazebo_plugin_tutorial/hello_world.cc:1:21: fatal error: gazebo.hh: No such file or directory

I did a locate and found gazebo.hh in

/opt/ros/fuerte/stacks/simulator_gazebo/gazebo/gazebo/include/gazebo-1.0.2/gazebo/gazebo.hh

Does the problem has anything to do with my ROS_PACKAGE_PATH or ROS_WORKSPACE? I've tried adding the above location to my ROS_PACKAGE_PATH but to no avail. My ROS_WORKSPACE is /home/u0905937/fuerte_workspace if that is any help.

I'm running on Ubuntu 12.04

EDIT: Thanks Kai, I've tried using the rosmake method and at least it could partially build the package.

But I still face the problem of the computer not being able to find gazebo.hh. I've tried copying gazebo.hh into /usr/include/ but it came up with a new error of not being able to find the next header which is gazebo_core.hh. So I copy and pasted it again which brought up another new error of not being able to find the next header the previous one referred to. There's got to be an easier way right?

By the way, my system is downgraded to ubuntu 11.10.