Collision issue

asked 2017-02-05 14:08:43 -0500

burf2000 gravatar image

updated 2017-02-24 02:46:31 -0500

So I have just got my custom robot going around the Kitchen, its running Hector Slam, Lidar etc. /odom is from the Hector not encoders, however it is working quiet well.

The only issue is the when I navigate it to a place, the collision seems to be a little out, it gets too close to an obstacle. I have the footprint set-up I have a URDF with a base_frame set-up (the robot is about 18cm square). In RVIZ I have ticked the collision box on the model. I want to make sure the robot does not get a x amount of cm to an object

obstacle_range: 2.5 
raytrace_range: 3.0 
footprint: [ [0.10, 0.10], [-0.10, 0.10], [-0.10, -0.10], [0.10, -0.10] ] 
inflation_radius: 0.05 


      <link name="base_frame">
        <visual>
          <geometry>
            <box size="0.18 0.18 0.07"/>
          </geometry>
          <origin rpy="0 0 0" xyz="0 0 0.085"/>
          <material name="white">
            <color rgba="1 1 1 1"/>
          </material>
        </visual>
        <collision>
          <geometry>
            <box size="0.18 0.18 0.07"/>
          </geometry>
        </collision>
      </link>

I adjusted the values a little, below are some pictures before and afte crash Randomly, it worked fine the first and 3rd time

image description image description image description image description

local_costmap:
   global_frame: /map
   robot_base_frame: /scanmatcher_frame 
   update_frequency: 5.0 
   publish_frequency: 2.0
   static_map: false 
   rolling_window: true 
   width: 4.0 # The width of the map in meters. default 10
   height: 4.0 # The height of the map in meters. default 10
   resolution: 0.05 # The resolution of the map in meters/cell. default 0.05
   transform_tolerance: 0.5 

global_costmap:
   global_frame: /map
   robot_base_frame: /scanmatcher_frame 
   update_frequency: 1.0 
   publish_frequency: 0.5
   static_map: true # 
   transform_tolerance: 0.5


obstacle_range: 2.5 
raytrace_range: 3.0
footprint: [ [0.08, 0.08], [-0.08, 0.08], [-0.08, -0.08], [0.08, -0.08] ] 
inflation_radius: 0.3 
map_type: costmap 
observation_sources: scan bump 

scan: {data_type: LaserScan, topic: scan, marking: true, clearing: true, min_obstacle_height: 0.25, max_obstacle_height: 0.35}
bump: {data_type: PointCloud2, topic: mobile_base/sensors/bumper_pointcloud, marking: true, clearing: false, min_obstacle_height: 0.0, max_obstacle_height: 0.15}

TrajectoryPlannerROS:
# Robot Configuration Parameters
  max_vel_x: 0.5
  min_vel_x: 0.1

  max_vel_theta:  1.5  
  min_vel_theta: -1.5 
  min_in_place_vel_theta: 1.0

  acc_lim_x: 0.6
  acc_lim_theta: 1.0

# Goal Tolerance Parameters
  yaw_goal_tolerance: 3.14 
  xy_goal_tolerance: 0.15 

# Forward Simulation Parameters
  sim_time: 3.0
  vx_samples: 6
  vtheta_samples: 20 

# Trajectory Scoring Parameters
  meter_scoring: true
  pdist_scale: 0.6
  gdist_scale: 0.8 
  occdist_scale: 0.01 
  heading_lookahead: 0.325 
  dwa: true 

# Oscillation Prevention Parameters
  oscillation_reset_dist: 0.05 

# Differential-drive robot configuration
  holonomic_robot: false
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Comments

1

I think the footprint should be little bigger than your robot size. It will effect the dilation area of obstacles.

FrozenCh gravatar imageFrozenCh ( 2017-02-05 20:25:56 -0500 )edit

Thank you, so collision detection should just happen?

burf2000 gravatar imageburf2000 ( 2017-02-06 01:49:37 -0500 )edit
1

If you use the navigation stack, the collision detection would be processed into two parts, local cost map and local planner. Local cost map would use your footprint, inflation_radius, map etc. to generate a cost map. Thus, local planner can use the cost map to move robot.

FrozenCh gravatar imageFrozenCh ( 2017-02-06 02:48:49 -0500 )edit

I wonder why it is not working, https://github.com/burf2000/ROS_Robot...

burf2000 gravatar imageburf2000 ( 2017-02-06 03:05:07 -0500 )edit

Can you print screen on the rviz, in which showing the local cost map and footprint at the place your collision failed?

FrozenCh gravatar imageFrozenCh ( 2017-02-06 03:21:24 -0500 )edit

I can tonight mate :) is it worth emailing it to you?

burf2000 gravatar imageburf2000 ( 2017-02-06 04:13:05 -0500 )edit
3

Email is good, but I think if we solve this issue on this forum is better for this community.

FrozenCh gravatar imageFrozenCh ( 2017-02-06 04:48:38 -0500 )edit
1

Yes, please attach the image to your OP, @burf2000. You have enough karma to do it.

gvdhoorn gravatar imagegvdhoorn ( 2017-02-06 05:05:35 -0500 )edit