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foot print non circular move base

asked 2020-11-23 02:44:06 -0500

dinesh gravatar image

I have a robot which has a rectangular body i.e 50*80 cm. How to use this robot in move base such that while autonomously navigating it don't collides with any object. For better result right now i've placed the 2d lidar at the center of the robot.

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answered 2020-11-23 08:09:24 -0500

tryan gravatar image

Set the footprint parameter of your costmap configuration to a list of points defining the bounding box as described in the navigation robot setup tutorial. Here's the example costmap configuration file given there:

obstacle_range: 2.5
raytrace_range: 3.0
footprint: [[x0, y0], [x1, y1], ... [xn, yn]]
#robot_radius: ir_of_robot
inflation_radius: 0.55

observation_sources: laser_scan_sensor point_cloud_sensor

laser_scan_sensor: {sensor_frame: frame_name, data_type: LaserScan, topic: topic_name, marking: true, clearing: true}

point_cloud_sensor: {sensor_frame: frame_name, data_type: PointCloud, topic: topic_name, marking: true, clearing: true}
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will it make the robot avoid obstacles? cas as i saw the local and global costmap are defined by the minimum measurement of robot. in case of rectngular robot its breath.

dinesh gravatar image dinesh  ( 2020-11-24 01:20:34 -0500 )edit

The footprint parameter defines a bounding polygon. It's then up to the planner (and its tuning) to ensure the robot doesn't collide with obstacles. As described in the costmap_2d documentation, the global and local costmaps usually have an inflation layer that adds a prohibited zone (lethal cost) near obstacles based on the smallest dimension of the footprint (automatically determined). Physically, the robot cannot possibly be within that zone without colliding, so it is forbidden to the planner. The robot is allowed to be close as it may avoid collisions depending on its orientation, though. Therefore, the planner should check that the footprint does not intersect (collide) with an obstacle along a trajectory before selecting that course. Furthermore, the planner tuning determines the cost of approaching obstacles, which you can set high to encourage the planner to choose routes farther from obstacles where available.

tryan gravatar image tryan  ( 2020-11-24 08:09:49 -0500 )edit

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Asked: 2020-11-23 02:44:06 -0500

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Last updated: Nov 23 '20