TurtleBot3 moving opposite direction of the goal

asked 2022-09-13 11:13:06 -0500

gcc05 gravatar image

updated 2022-09-15 05:07:29 -0500

I have some TurtleBot3 (waffle pi), and I have observed some weird behavior both in simulation and in the real robot. I set up the navigation to move forward only, given that otherwise it will sometimes move backwards and the camera is in the front.

This works, however, I have observed that if I send a goal which is just behind the robot, the robot will start to move forward in the opposite direction of the goal until it finds an obstacle, and it will then turn and go towards the goal. This seems like a very strange behavior, but I have not managed to find out how to fix it. Has anyone else experienced this or knows how to fix it?

Thanks!

Edit: Adding videos of the issue: https://gifyu.com/image/SwezC Here, I send a goal just behind the robot, and the robot moves forward until it can't anymore and then turns. However, it could have turned way before reaching the other side.

In this other video: https://gifyu.com/image/Swepm the robot does the same but then does not turn and gets stuck there.

In both cases the global plan is fine, but the local plan moves the robot to the other direction.

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Comments

I would like to suggest you few troubleshooting steps. 1. How did you calibrated camera and robot transformations. 2. Check the command direction that you are publishing to move the robot simply by manually sending the commands using the terminal to see how does it react with the given values. 3. After this you will be able to make sure where you are doing it wrong, whether there is some error in data you are publishing to move the robot or camera transform.

I hope it helps

akumar3.1428 gravatar image akumar3.1428  ( 2022-09-13 15:07:22 -0500 )edit

Hi akumar, thanks for the reply! Just to clarify, the robot navigates correctly, it only happens when the goal is behind itself. This happens using the default turtlebot3 packages and in simulation and publishing the goal on rviz. Transforms look fine, and calibration I assume also fine as it navigates nicely when the goal is anywhere else. I'm quite confused at this one..!

gcc05 gravatar image gcc05  ( 2022-09-13 15:29:51 -0500 )edit

I added a video of the issue in case it helps.

gcc05 gravatar image gcc05  ( 2022-09-15 04:50:05 -0500 )edit