bzhan's profile - activity

Is there a ROS package that uses IMU data to determine positional movement (for example, relative to the start location), based on the existing IMU data like acceleration?

Hi, I'm hoping to create a virtual joystick or use my android phone as a joystick so that I don't need the physical joystick to be with me at all times, but couldn't figure out how to do so online. In particular, the app I'm creating reads out of the buttons and axes. Are there any suggestions? I am using ROS indigo

I was reading this guide: http://wiki.ros.org/rtabmap_ros/Tutor...

I am unsure whether rtabmap supports moving objects (for example, after generating a map, if a chair moves, or if the mapping captured a person who is moving, do these things throw off rtabmap's localization)?

Hi, I am trying to use visual odometry to do localization. Is there any code/ROS library that enables you to get visual odometry data before the map is built? Or automatically starts when enough locations has been detected?

I'm looking at the Rtabmap library and it asks that a map (with at least 30 locations) is first built before localization is performed, as per this guide. I am open to using other libraries too.

I just tried this: for me, it only artificially zeros out the angular velocities? Basically, when the condition is satisfied, the items will be published as 0, but when it is not, the values will be published incorrectly again?

I was wondering whether robot_localization package merges RPY and quaternion orientation data for you (from 2 different sensors), or whether this needs to be done manually prior to sending it to the package?

probably because of IMU, you should output its data to see whether that is drifting significantly enough that it was primary cause of the drift; I calibrated mine using the husky_robot code (here it is for reference) https://github.com/brianzhan/husky_ro...

Got it, thank you so much for the help!

I actually couldn't figure out where/how the while or if condition there checks for threshold of zeros values in the code you linked?

Thank you so much!

Thanks a lot! May I ask, what you changed to zero out the values? I'm not sure what part of the code to alter

Hi, I am trying to figure out how to zero out the orientation and linear acceleration of my IMU, so that when I launch it, the x and y values begin at 0, rather than at some value like orientation of 0.126.

Anything would help, but my code for using my IMU is here for reference: https://github.com/brianzhan/husky_ro...

Below is a sample of the message when I launch my um6.launch script, where orientation and linear acceleration don't begin at 0. It is necessary for me get it to 0 to fuse it with my wheel odometry data and other tasks:

header: 
  seq: 456
  stamp: 
  secs: 1463184035
  nsecs: 667352940
  frame_id: imu_link
orientation: 
  x: 0.0279296576
  y: 0.1263548452
  z: -0.9905964737
  w: 0.0441436295
orientation_covariance: [0.01596195437014103, -0.0012914746766909957, -0.0005610909429378808, -0.0012914201943203807, 0.012185076251626015, 0.00017108242900576442, -0.0005610864027403295, 0.0001710832875687629, 0.011863413266837597]
angular_velocity: 
  x: 0.00319579559884
  y: -0.00106526519961
  z: -0.00106526519961
angular_velocity_covariance: [2.5e-05, 0.0, 0.0, 0.0, 2.5e-05, 0.0, 0.0, 0.0, 2.5e-05]
linear_acceleration: 
  x: -0.03952058
  y: 0.4311336
  z: -10.28073997
linear_acceleration_covariance: [0.0036, 0.0, 0.0, 0.0, 0.0036, 0.0, 0.0, 0.0, 0.0036]

Hi, I am currently using the following two files to calibrate my IMU.

https://github.com/husky/husky_robot/...

https://github.com/husky/husky_robot/...

Where I run ./calibrate_compass, which calls compute_calibration. I was wondering what the IMU should be doing while calibration is occurring. Should it be spinning precisely around its center or should it be stationary?

Hi, I am currently using roslaunch to launch the following to use the imu_filter_madgwick package:

<node pkg="imu_filter_madgwick" type="imu_filter_node" name="IMU_node2" output="screen">
    <param name="use_mag" value="false"/>
    <param name="publish_tf" value="false"/>
    <param name="fixed_frame" value="odom_combined"/>
    <remap from="imu/data" to="imu_data"/>    
  </node>

I am using the UM6 IMU. After launching, I get the following messages in terminal, which indicates the package was indeed run:

[ INFO] [1462574747.547080189]: Starting ImuFilter [ INFO] [1462574747.549628034]: Using dt computed from message headers [ INFO] [1462574747.555848218]: Imu filter gain set to 0.100000 [ INFO] [1462574747.555877373]: Gyro drift bias set to 0.000000 [ INFO] [1462574747.555897099]: Magnetometer bias values: 0.000000 0.000000 0.000000

However, when I try to run rostopic echo imu/data or rostopic echo imu_data, there is no output. I was wondering if someone can help guide me on what I did wrong? Thank you in advance.

Hi, I'm currently trying to compute my IMU's calibration. The IMU is UM6r2--the vendor only provides a way to calibrate on Windows--I am running the robot on Ubuntu.

I saw in a previous post that a generic IMU calibrator that would work would be the one found here: https://github.com/husky/husky_robot/...

My interpretation was that this code should set HUSKY_MAG_CONFIG,https://github.com/husky/husky_robot/blob/indigo-devel/husky_bringup/CMakeLists.txt. (I ran this code by cloning the husky_robots directory, adding husky_bringup directory into the src folder, then calling catkin_make)

When I then try calling um6.launch, I get the following bug message: environment variable 'HUSKY_MAG_CONFIG' is not set

I believe that HUSKY_MAG_CONFIG will do the calibration because of it references mag_config.yaml, which is found in calibrate_compass

Much appreciated if someone could help. I am also open to other ways of calibration