search

tkkim-robot / SLAM_Wiki

Just some private study notes for SLAM
8 stars 1 forks source link

Clarification #3

Closed nyangshawbin closed 3 years ago

nyangshawbin commented 4 years ago

Hi @ktk1501, first of all huge thank you for the documentation on wikihow, really helped me to understand more about Hdl graph slam! I am running the slam offline on a rosbag, recorded from a Gazebo simulation. However, there are some points you mentioned in your documentation which i would like to clarify:

  1. I currently have "base_link" as the frame_id for my /imu/data. Is changing the frame_id to "velodyne" the only thing i need to do? Another reason im asking is because i am using my /imu/data as it is and i dont see anything errors.
  2. For setting the parameter distance_thres, is it recommeded that the red sphere always covers the start point at any instance of its entire trajectory? It seems that loop closure is done when not needed as shown in the picture below when the robot is making a left turn, does it mean i have to reduce the fitness_score_thresh?

Thank you in advance!!

improper_loop_closure

Following are some files which may help you to understand my setup: Husky URDF Hdl graph slam launch file

tkkim-robot commented 3 years ago

Hi @nyangshawbin. Sorry for very late reply..

  1. Yes. Or you need to set a TF between two frame_id. You can do it by static transform publisher or by ROS coding.
  2. Yes. You have to adjust parameters for the sensitivity of loop closing. You can do it by the way of you mentioned. If thing not going well, you must adjust some another params.

Thanks !