Map Server / Saver¶

Source code on Github.

The Map Server implements the server for handling the map load requests for the stack and host a map topic. It also implements a map saver server which will run in the background and save maps based on service requests. There exists a map saver CLI similar to ROS 1 as well for a single map save.

Map Saver Parameters¶

save_map_timeout:

Type	Default
int	2.0

Description: Timeout to attempt saving the map (seconds).

free_thresh_default:

Type	Default
double	0.25

Description: Free space maximum probability threshold value for occupancy grid.

occupied_thresh_default:

Type	Default
double	0.65

Description: Occupied space minimum probability threshhold value for occupancy grid.

Map Server Parameters¶

yaml_filename:

Type	Default
string	N/A

Description: Path to map yaml file.

topic_name:

Type	Default
string	“map”

Description: Topic to publish loaded map to.

frame_id:

Type	Default
string	“map”

Description: Frame to publish loaded map in.

Costmap Filter Info Server Parameters¶

type:

Type	Default
int	0

Description

Type of costmap filter used. This is an enum for the type of filter this should be interpreted as. We provide the following pre-defined types:

0: keepout zones / preferred lanes filter
1: speed filter, speed limit is specified in % of maximum speed
2: speed filter, speed limit is specified in absolute value (m/s)

filter_info_topic:

Type	Default
string	“costmap_filter_info”

Description: Topic to publish costmap filter information to.

mask_topic:

Type	Default
string	“filter_mask”

Description: Topic to publish filter mask to. The value of this parameter should be in accordance with topic_name parameter of Map Server tuned to filter mask publishing.

base:

Type	Default
double	0.0

Description: Base of OccupancyGrid mask value -> filter space value linear conversion which is being proceeded as: filter_space_value = base + multiplier * mask_value

multiplier:

Type	Default
double	1.0

Description: Multiplier of OccupancyGrid mask value -> filter space value linear conversion which is being proceeded as: filter_space_value = base + multiplier * mask_value

Example¶

map_server:
  ros__parameters:
    yaml_filename: "turtlebot3_world.yaml"
    topic_name: "map"
    frame_id: "map"

map_saver:
  ros__parameters:
    save_map_timeout: 5.0
    free_thresh_default: 0.25
    occupied_thresh_default: 0.65

costmap_filter_info_server:
  ros__parameters:
    type: 1
    filter_info_topic: "costmap_filter_info"
    mask_topic: "filter_mask"
    base: 0.0
    multiplier: 0.25