The common parameters of the local and global costmaps are discussed in this section. The costmap is created using the obstacles present around the robot. Fine tuning the parameters of the costmap can increase the accuracy of map generation. The customized file costmap_common_params.yaml of Chefbot follows. This configuration file contains the common parameters of both the global and the local cost maps. It is present in the chefbot_bringup/param folder. For more about costmap common parameters, check http://wiki.ros.org/costmap_2d/flat.

#The maximum value of height which has to be taken as an obstacle  
max_obstacle_height: 0.60   
 
#This parameters set the maximum obstacle range. In this case, the robot will only look at obstacles within 2.5 meters in front of robot  
obstacle_range: 2.5 
 
#This parameter helps robot to clear out space in front of it upto 3.0 meters away given a sensor reading 
raytrace_range: 3.0 
 
#If the robot is circular, we can define the robot radius, otherwise we need to mention the robot footprint 
 
robot_radius: 0.45 
#footprint: [[-0.,-0.1],[-0.1,0.1], [0.1, 0.1], [0.1,-0.1]] 
 
#This parameter will actually inflate the obstacle up to this distance from the actual obstacle. This can be taken as a tolerance value of obstacle. The cost of map will be same as the actual obstacle up to the inflated value.  
 
inflation_radius: 0.50   
 
#This factor is used for computing cost during inflation 
cost_scaling_factor: 5   
 
#We can either choose map type as voxel which will give a 3D view of the world, or the other type, costmap which is a 2D view of the map. Here we are opting voxel. 
map_type: voxel 
 
#This is the z_origin of the map if it voxel 
origin_z: 0.0 
 
#z resolution of map in meters 
z_resolution: 0.2 
 
#No of voxel in a vertical column 
z_voxels: 2 
 
#This flag set whether we need map for visualization purpose 
publish_voxel_map: false 
 
#A list of observation source in which we get scan data and its parameters 
observation_sources: scan 
 
#The list of scan, which mention, data type of scan as LaserScan, marking and clearing indicate whether the laser data is used for marking and clearing costmap.  
 
scan: {data_type: LaserScan, topic: scan, marking: true, clearing: true, min_obstacle_height: 0.0, max_obstacle_height: 3} 

After discussing the common parameters, we will now look at the global costmap configuration.