🚓D.16 Behavior Server

Source code on Github.

The Behavior Server implements the server for handling recovery behavior requests and hosting a vector of plugins implementing various C++ behaviors. It is also possible to implement independent behavior servers for each custom behavior, but this server will allow multiple behaviors to share resources such as costmaps and TF buffers to lower incremental costs for new behaviors.

Note: the wait recovery behavior has no parameters, the duration to wait is given in the action request. Note: pre-Rolling/Humble this was the Recovery server, not behavior server. Launch files, behaviors and tests were all renamed.

Behavior Server Parameters

Name	Description	Type	Default
local_costmap_topic	Raw costmap topic for collision checking on the local costmap.(costmap topic အကြမ်းမှာ collision တွေကို check လုပ်ပေးတယ် (local costmap မှာပေ့ါ)	string	“local_costmap/costmap_raw”
global_costmap_topic	Raw costmap topic for collision checking on the global costmap.(global costmap ပုံကြမ်းမှာ coll	string	“global_costmap/costmap_raw”
local_footprint_topic	Topic for footprint in the local costmap frame.( local costmap frame အတွက် footprint topic)	string	“local_costmap/published_footprint”
global_footprint_topic	Topic for footprint in the global costmap frame.( global costmap frame အတွက် footprint	string	“global_costmap/published_footprint”
cycle_frequency	Frequency to run behavior plugins. ( behavior plugin တွေ run ဖို့ အတွက် frequency)	double	10.0
transform_tolerance	TF transform tolerance.	Double	0.1
local_frame	Local reference frame.	string	"odom"
global_frame	Global reference frame.	string	"map"
robot_base_frame	Robot base frame.	string	"base_link"
behavior_plugins	List of plugin names to use, also matches action server names. Note: Each plugin namespace defined in this list needs to have a plugin parameter defining the type of plugin to be loaded in the namespace. ( plugin တိုင်းမှာ plugin parameter သက်မှတ်ပေးရပါမယ်။ plugin တွေမှာလည်း namespace type ထည့်ပေးရမယ်ပေါ့။)	vector<string>	{“spin”, “back_up”, “drive_on_heading”, “wait”}

behavior_server:
  ros__parameters:
    behavior_plugins: ["spin", "backup", "drive_on_heading", "wait"]
    spin:
      plugin: "nav2_behaviors/Spin"
    backup:
      plugin: "nav2_behaviors/BackUp"
    drive_on_heading:
      plugin: "nav2_behaviors/DriveOnHeading"
    wait:
      plugin: "nav2_behaviors/Wait"

Default Plugins

Spin Behavior Parameters

Name	Description	Type	Default
simulate_ahead_time	Time to look ahead for collisions (s).	double	2.00
max_rotational_vel	Maximum rotational velocity (rad/s).	double	1.0
min_rotational_vel	Minimum rotational velocity (rad/s).	double	0.4
rotational_acc_lim	maximum rotational acceleration (rad/s^2).	double	3.2

BackUp Behavior Parameters

Name	Description	Type	Default
simulate_ahead_time	Time to look ahead for collisions (s).	double	2.0

DriveOnHeading Behavior Parameters

Name	Description	Type	Default
simulate_ahead_time	Time to look ahead for collisions (s).	double	2.0

AssistedTeleop Behavior Parameters¶

Name	Description	Type	Default
projection_time	Time to look ahead for collisions (s).	double	1.0
simulation_time_step	Time step for projections (s).	double	0.1
cmd_vel_teleop	Topic to listen for teleop messages.	string	cmd_vel_teleop

နမူနာ

behavior_server:
  ros__parameters:
    local_costmap_topic: local_costmap/costmap_raw
    local_footprint_topic: local_costmap/published_footprint
    global_costmap_topic: global_costmap/costmap_raw
    global_footprint_topic: global_costmap/published_footprint
    cycle_frequency: 10.0
    behavior_plugins: ["spin", "backup", "drive_on_heading", "wait", "assisted_teleop"]
    spin:
      plugin: "nav2_behaviors/Spin"
    backup:
      plugin: "nav2_behaviors/BackUp"
    drive_on_heading:
      plugin: "nav2_behaviors/DriveOnHeading"
    wait:
      plugin: "nav2_behaviors/Wait"
    assisted_teleop:
      plugin: "nav2_behaviors/AssistedTeleop"
    local_frame: odom
    global_frame: map
    robot_base_frame: base_link
    transform_timeout: 0.1
    simulate_ahead_time: 2.0
    max_rotational_vel: 1.0
    min_rotational_vel: 0.4
    rotational_acc_lim: 3.2