Thank you very much for your answer guys! Actually I didn't think about the laser's position on the simulations. It is, in fact, mounted on top of each robot. Therefore, one laser does not see the body of other robots due to their heights. Eitan's idea to publish a point cloud of obstacle data sounds really nice. Nevertheless, I am going to try to adjust the laser's height firstly in the .world file on stage to check how the navigation stack handles the multi-robot case and if I feel that is necessary I will also implement Eitan's idea. My .world file is: ----------------------------------------------------------------------------------------------------- define hokuyo laser( range_max 2.0 fov 270.25 samples 1081 color "black" size [ 0.05 0.05 0.1 ] ) define robot position( size [0.33 0.33 0.1] # This block approximates a circular shape of a Robot block ( points 16 point[0] [ 0.225 0.000 ] point[1] [ 0.208 0.086 ] point[2] [ 0.159 0.159 ] point[3] [ 0.086 0.208 ] point[4] [ 0.000 0.225 ] point[5] [ -0.086 0.208 ] point[6] [ -0.159 0.159 ] point[7] [ -0.208 0.086 ] point[8] [ -0.225 0.000 ] point[9] [ -0.208 -0.086 ] point[10] [ -0.159 -0.159 ] point[11] [ -0.086 -0.208 ] point[12] [ -0.000 -0.225 ] point[13] [ 0.086 -0.208 ] point[14] [ 0.159 -0.159 ] point[15] [ 0.208 -0.086 ] color "gray50" ) hokuyo( pose [0 0 0.1 0] ) color "gray50" ) window( size [ 720 692 1] rotate [ 0.000 0.000 ] center [5.975 6.225 ] scale 35 show_data 1 ) define floorplan model ( # Sombre, sensible, artistic color "gray30" # Most maps will need a bounding box boundary 1 gui_nose 0 gui_grid 0 gui_move 0 gui_outline 0 gripper_return 0 fiducial_return 0 laser_return 1 ) floorplan ( size [11.95 12.45 1] pose [5.975 6.225 0 0] bitmap "1r-5-map.pgm" ) robot( # Can refer to the robot by this name name "robot0" pose [ 5.80 7.35 0 90.0 ] drive "diff" localization "gps" localization_origin [ 0 0 0 0 ] ) robot( # Can refer to the robot by this name name "robot1" pose [ 1.00 7.50 0 90.0 ] drive "diff" localization "gps" localization_origin [ 0 0 0 0 ] ) ----------------------------------------------------------------------------------------------------- I believe I just have to change the pose of the Hokuyo laser, right? Again, thank you very much for your hints. I hope to solve the problem soon :) Best Regards, David Portugal Mobile Robotics Laboratory Institute of Systems and Robotics University of Coimbra ________________________________________________________________________________ Junte todos os seus créditos no Único da Capital Mais... ...reduza as suas despesas mensais. Saiba mais em http://www.iol.pt/correio/rodape.php?dst=0901051