Ask Your Question
1

Robot moves forward only

asked 2016-02-04 07:16:39 -0600

Orhan gravatar image

updated 2016-02-05 08:43:28 -0600

Hi everyone,

Robot goes into narrow place but it can't go back to first position. It is trying to escape with moving a bit backward (then forward) infinitely at corridor's end. How can I make it escape all the way backwards? My Local Planner : base_local_planner/TrajectoryPlannerROS Gmapping's Hokuyo Laser is in the front of robot. And There is a small rplidar on the robot's rear for avoiding obstacles:

obstacle_layer:
     observation_sources: rplidar_back_scan scan
     rplidar_back_scan: {data_type: LaserScan, sensor_frame: /base_lidar_back_link, clearing: true, marking: true, topic: /rplidar_back_scan}
     scan: {data_type: LaserScan, sensor_frame: /base_laser_link, clearing: true, marking: true, topic: /scan}

Here is Rviz screenshot:

image description

Thank you.

EDIT1: Am I need to merge lasers? (And how to merge?) move_base updating costmap with all laser's scans but Gmapping uses only front laser.

EDIT2: I've set escape_vel to 0.0. Now robot just stopping at the corridor's end.

edit retag flag offensive close merge delete

Comments

1
F.Brosseau gravatar imageF.Brosseau ( 2016-02-05 06:39:57 -0600 )edit

Thank you. But escape_reset_theta and escape_reset_dist parameters aren't useful. Now it is 0.01. If I set this to 1.0, robot tries escape one meter for every obstacle.

Orhan gravatar imageOrhan ( 2016-02-05 07:03:35 -0600 )edit

And with the oscillation_reset_dist parameter?

F.Brosseau gravatar imageF.Brosseau ( 2016-02-05 07:07:26 -0600 )edit

I've tried before, It doesn't make sense too. :/

Orhan gravatar imageOrhan ( 2016-02-05 07:15:44 -0600 )edit

1 Answer

Sort by ยป oldest newest most voted
1

answered 2016-02-08 00:51:04 -0600

Orhan gravatar image

I have found solution. From David Lu's this answer: how to remove forward bias in move_base

I've changed local planner to dwa_local_planner/DWAPlannerROS and setted min_vel_x to negative value. Now robot goes backward succesfully.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower

Stats

Asked: 2016-02-04 07:16:39 -0600

Seen: 885 times

Last updated: Feb 08 '16