Lidar scan not matching with obstacles when using AMCL in Nav2, specially when the robot is rotating

Question

I am taking ground-truth odom and lidar scan messages from gazebo garden and using custom nodes to change the time stamps to ros2 time.

I verified that messages are correct in both systems. When lanching AMCL, setting pose using rviz the robot moves to initial pose and then on hitting Nav2Goal robot starts moving slowly in translation but when rotational goal sent, it struggles and lidar scan do no match at all and remains static with the robot movement.

warning like AMCL lookup would require into future from base_link to odom comes but I have looked numerous issues and these are just ignored in them. Also when I set pose estimate completely opposite direction robot comes to that pose in rviz but not in gazebo.

One thing I suspect is the robot is skidding in gazebo might be that's why it is not moving properly?

In rqt, the scan topic is coming at 2hz while odom is at 10 hz and tf is 22hz is this all causing issue. But if these were issues then lookup warning should show [Error] instead of [WARN].

My question is I need to how to solve this issue as nav2 seems launched properly as I am using default launch.

If anybody could advice or any walkaround it will be helpful.@steven-macenski

One thing is that I want everything to work on system/wall time.

Answer 1

if you are using robot localization package for publishing odom->base_link tf then check transform_time_offset: 0.0 parameter if its high try to reduce it.

else you can try the transform_tolerance: 1.0 parameter in amcl config you can try to increase this value to future date the time stamps for the tfs.

for gazebo i dont know but it helped with the rotational drift in my real robot.

Answer 2

Often it is necessary to rotate the robot slowly so that the Lidar mapping can keep up with the movement.

I had a problem in Gazebo making the robot too heavy, and it wasn't moving properly. When I lightened it in the parameters, it moved better.