Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Yaw problem in my wall following algorithm

asked 2012-10-02 14:40:35 -0500

leivas_gabriel
1 ●1 ●2 ●1

updated 2014-04-20 14:09:41 -0500

ngrennan
1 ●1 ●1

Hi,

I'm trying to create a wall following algorithm, but I'm having some problem. Essentially my code use laser to extract a line and calculate the slope (locally to the robot, so from 0 to 2*pi) but to make the control I need the robot yaw (0 to 3.14 and -3.14 to 0) so when I have a negative yaw for example -1.59 and a slope of 1.61 my error that is error=(slope-yaw). Causes the robot turn to the wrong direction :(

Somebody already have the same problem with angles in ROS ?

Gabriel Oliveira

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2012-10-02 16:02:22 -0500

david.hodo

395 ●11 ●16 ●21 http://www.davidwhodo.com/

updated 2012-10-02 19:02:39 -0500

If you're using an error in an angle to feed a controller you generally need to wrap the error to be between -pi and pi as well. The way I normally do this is with the mod function in whatever language you're using. For example, the following will give an error that is always between -pi and pi

error=mod(slope-yaw+2*PI,2*PI)-PI

edit flag offensive delete link

add a comment

Question Tools

1 follower

Stats

Asked: 2012-10-02 14:40:35 -0500

Seen: 692 times

Last updated: Oct 02 '12

Yaw problem in my wall following algorithm edit

1 Answer

Question Tools

Stats

Related questions

Yaw problem in my wall following algorithm