pmarinplaza's profile - activity

Very nice answer, I'll see that code and see what I can use. In my case, I am using pr2 manager to control the joints and I want to know if I can control the joint in velocity (like rpm) because torque force depends on weight. Thank you very much ;)

Hello,

I want to know how the joints work with gazebo. My problem is that I don't know what kind of physics laws are used for gazebo.

I am using one plugin for control the wheels on (4 wheel) differential car. I am using one class in the pkg pr2_controller/manager and one of my question is the next:

In this plugin, there are 3 states, star, update and stop. I configure update to 50 Hz. Every time to run this state, I send efforts to joints by this way:

std::string joint_blw;
  if (!n.getParam("joint_blw", joint_blw))
  {
    ROS_ERROR("No joint BLW given in namespace: '%s')",
              n.getNamespace().c_str());
    return false;
  }
  joint_state_blw_ = robot->getJointState(joint_blw);
  if (!joint_state_blw_)
  {
    ROS_ERROR("summit_xl_ctrl could not find joint named '%s'",
              joint_blw.c_str());
    return false;
  }
  ROS_DEBUG("summit_xl_ctrl found joint named '%s'", joint_blw.c_str());
...
...
joint_state_blw_->commanded_effort_ = ...

This joint is continuous and has this urdf:

.. ..

  <joint name="joint_back_left_wheel" type="continuous">
    <parent link="base_link"/>
    <child link="back_left_wheel"/>
    <origin xyz="-0.223 0.154 0" rpy="0 0 0" /> 
    <axis xyz="0 1 0" rpy="0 0 0" />
    <limit effort="100" velocity="100"/>
    <joint_properties damping="0.0" friction="0.0"/>
  </joint>

  <transmission name="joint_blw_trans" type="pr2_mechanism_model/SimpleTransmission">
     <actuator name="joint_blw_motor" />
     <joint name="joint_back_left_wheel" />
     <mechanicalReduction>1</mechanicalReduction>
     <motorTorqueConstant>1</motorTorqueConstant>
  </transmission>

Finally, I don't know where is this effort apply and what is the performance of this effort, like I send torque to make par or whatever in N or Nm?. Where can I find any documentation or tutorial about this?

By the Way this is for the Uc3m University

Yes. The people of Hector fix the problem and it works very well now.

Hello Team,

I am using the plugin hector_gazebo_ros_sonar.so of the package hector_gazebo_plugins but the performance is very bad.

My problem is describe here: link:here

I am looking for another sensor which works a little better. Anybody know another sonar sensor plugin?

It is to do a study to explain the best position of these sonar sensors around the robot vs Kinect in some cases.

Thanks a lot.