Jacob Lambert's profile - activity

Thanks! bit strange to have to chmod +x your node.py files when coming over from python to c++..

I had this error because I had a newer version of cmake installed. libeigen3-dev had installed FindEigen3.cmake in usr/s

Decreased step size dramatically, increased number of iterations. Gravity vector is well behaved but accelerations in the plane are still crazy. Played around with the model but it didn't seem to help, I'll take a look at how the Jackal does it.

I thought it might be something like that but wasn't sure what to do about it. I'll see how much I can mitigate these effects and report back. TY

Updated. I guess you had no luck fixing it? I tried finding a model that includes a hector IMU but could not find one. I haven't seen any examples out there, just this guy who seems to have managed to get it to behave

Hi,

I am trying to use the IMU plugin in Gazebo (v2.2.5) but am seeing weird behavior. I am running the IMU without biases or noise, and the acceleration/rate outputs integrate to trajectories I expect, but the measurements are nevertheless erratic: they are constantly switching sign. I publish sinusoidal velocities in gazebo so I know what to expect from the acceleration measurements, but they look like this:

Whole dataset (a_x, a_y, w)

Zoomed in

I don't expect perfectly smooth trajectories but 50m/s^2 accels at times seems too unstable, something must be wrong. If I just look at the gravity vector in rviz it jumps all over the place. I tried to set everything to zero...

<!-- Chassis -->
    <link name="base_link">
        <inertial>
            <mass value="10.0"/>
            <origin xyz="0 0 0.177"/>
            <inertia 
                 ixx="0.3338" ixy="0.0" ixz="0.0"
                 iyy="0.4783" iyz="0.0"
                 izz="0.3338"/>
        </inertial>
        <visual name="base_visual">
            <origin xyz="0 0 0.177" rpy="0 0 0"/>
            <geometry name="pioneer_geom">
                <mesh filename="package://dopebot_description/meshes/chassis.stl"/>
            </geometry>
            <material name="ChassisRed">
                <color rgba="0.851 0.0 0.0 1.0"/>
            </material>
        </visual>
        <collision>
            <origin xyz="0 0 0.177" rpy="0 0 0"/>
                <geometry>
                    <mesh filename="package://dopebot_description/meshes/chassis.stl"/>
                </geometry>
        </collision>
    </link> 

<!-- IMU -->
<link name="imu_link">
  <inertial>
    <mass value="0.001"/>
    <origin rpy="0 0 0" xyz="0 0 0"/>
    <inertia ixx="0.0001" ixy="0" ixz="0" iyy="0.0001" iyz="0" izz="0.0001"/>
  </inertial>

  <visual>
    <origin rpy="0 0 0" xyz="0 0 0"/>
    <geometry>
      <box size="0.1 0.1 0.1"/>
    </geometry>
  </visual>

  <collision>
    <origin rpy="0 0 0" xyz="0 0 0"/>
    <geometry>
      <box size="0.1 0.1 0.1"/>
    </geometry>
  </collision>
</link>

<!-- IMU Joint -->
  <joint name="imu_joint" type="fixed">
    <axis xyz="1 0 0"/> <!-- 0 1 0 -->
    <origin xyz="0 0 0.28"/>
    <parent link="base_link"/>
    <child link="imu_link"/>
  </joint>

      <plugin name="imu_plugin" filename="libhector_gazebo_ros_imu.so">
            <updateRate>1000</updateRate>
            <bodyName>base_link</bodyName>
            <topicName>/imu</topicName>
            <serviceName>/imu/calibrate</serviceName>
            <accelOffset>0.0 0.0 0.0</accelOffset>
            <accelDrift>0.0 0.0 0.0</accelDrift>
            <accelDriftFrequency>0.0 0.0 0.0</accelDriftFrequency>
            <accelGaussianNoise>0.0 0.0 0.0</accelGaussianNoise>
            <rateOffset>0.0 0.0 0.0</rateOffset>
            <rateDrift>0.0 0.0 0.0</rateDrift>
            <rateDriftFrequency>0.0 0.0 0.0</rateDriftFrequency>
            <rateGaussianNoise>0.0 0.0 0.0</rateGaussianNoise>
            <headingOffset>0.0</headingOffset>
            <headingDrift>0.0</headingDrift>
            <headingDriftFrequency>0.0</headingDriftFrequency>
            <headingGaussianNoise>0.0</headingGaussianNoise>
            <rpyOffset>0.0 0.0 0.0</rpyOffset>
            <xyzOffset>0.0 0.0 0.0</xyzOffset>
            <gaussianNoise>0.0</gaussianNoise>
        </plugin>

but the problem remains. Any ideas?

Thank you,

Jacob