Behavior Server

Source code on Github.

The Behavior Server implements the server for handling various behavior, such as recoveries and docking, 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.

Behavior Server Parameters

`local_costmap_topic`

Type: string Default: "local_costmap/costmap_raw": Raw costmap topic for collision checking on the local costmap.

`global_costmap_topic`

Type: string Default: "global_costmap/costmap_raw": Raw costmap topic for collision checking on the global costmap.

`local_footprint_topic`

Type: string Default: "local_costmap/published_footprint": Topic for footprint in the local costmap frame.

`global_footprint_topic`

Type: string Default: "global_costmap/published_footprint": Topic for footprint in the global costmap frame.

`cycle_frequency`

Type: double Default: 10.0: Frequency to run behavior plugins.

`transform_tolerance`

Type: double Default: 0.1: TF transform tolerance.

`local_frame`

Type: string Default: "odom": Local reference frame.

`global_frame`

Type: string Default: "map": Global reference frame.

`robot_base_frame`

Type: string Default: "base_link": Robot base frame.

`introspection_mode`

Type: string Default: "disabled": The introspection mode for services and actions. Options are "disabled", "metadata", "contents".

`behavior_plugins`

Type: vector<string> Default: ["spin", "backup", "drive_on_heading", "wait"]

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.

Example:

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

When the behavior_plugins parameter is not overridden, the following default plugins are loaded:

Namespace	Plugin
"spin"	"nav2_behaviors::Spin"
"backup"	"nav2_behaviors::BackUp"
"drive_on_heading"	"nav2_behaviors::DriveOnHeading"
"wait"	"nav2_behaviors::Wait"

Spin Behavior Parameters

Spin distance is given from the action request

`simulate_ahead_time`

Type: double Default: 2.0: Time to look ahead for collisions (s).

`max_rotational_vel`

Type: double Default: 1.0: Maximum rotational velocity (rad/s).

`min_rotational_vel`

Type: double Default: 0.4: Minimum rotational velocity (rad/s).

`rotational_acc_lim`

Type: double Default: 3.2: Maximum rotational acceleration (rad/s^2).

`enable_stamped_cmd_vel`

Type: bool Default: true: Whether to use geometry_msgs::msg::Twist or geometry_msgs::msg::TwistStamped velocity data. true uses TwistStamped, false uses Twist.

BackUp Behavior Parameters

Backup distance, speed and time_allowance is given from the action request.

`simulate_ahead_time`

Type: double Default: 2.0: Time to look ahead for collisions (s).

`enable_stamped_cmd_vel`

Type: bool Default: true: Whether to use geometry_msgs::msg::Twist or geometry_msgs::msg::TwistStamped velocity data. true uses TwistStamped, false uses Twist.

`backup.acceleration_limit`

Type: double Default: 2.5: Maximum acceleration limit (m/s^2). This parameter limits the rate at which speed increases when moving backward.

`backup.deceleration_limit`

Type: double Default: -2.5: Maximum deceleration limit (m/s^2). Negative value. This parameter limits the rate at which speed decreases when moving backward.

`backup.minimum_speed`

Type: double Default: 0.1: Minimum speed to move, the deadband velocity of the robot behavior (m/s). Positive value.

DriveOnHeading Behavior Parameters

DriveOnHeading distance, speed and time_allowance is given from the action request.

`simulate_ahead_time`

Type: double Default: 2.0: Time to look ahead for collisions (s).

`enable_stamped_cmd_vel`

Type: bool Default: true: Whether to use geometry_msgs::msg::Twist or geometry_msgs::msg::TwistStamped velocity data. true uses TwistStamped, false uses Twist.

`bond_heartbeat_period`

Type: double Default: 0.25: The lifecycle node bond mechanism publishing period (on the /bond topic). Disabled if inferior or equal to 0.0.

`allow_parameter_qos_overrides`

Type: bool Default: true: Whether to allow QoS profiles to be overwritten with parameterized values.

`drive_on_heading.acceleration_limit`

Type: double Default: 2.5: Maximum acceleration limit (m/s^2).

`drive_on_heading.deceleration_limit`

Type: double Default: -2.5: Maximum deceleration limit (m/s^2). Negative value.

`drive_on_heading.minimum_speed`

Type: double Default: 0.1: Minimum speed to move, the deadband velocity of the robot behavior (m/s). Positive value.

AssistedTeleop Behavior Parameters

AssistedTeleop time_allowance is given in the action request

`projection_time`

Type: double Default: 1.0: Time to look ahead for collisions (s).

`simulation_time_step`

Type: double Default: 0.1: Time step for projections (s).

`cmd_vel_teleop`

Type: string Default: "cmd_vel_teleop": Topic to listen for teleop messages.

`enable_stamped_cmd_vel`

Type: bool Default: true: Whether to use geometry_msgs::msg::Twist or geometry_msgs::msg::TwistStamped velocity data. true uses TwistStamped, false uses Twist.

Example

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_tolerance: 0.1
    simulate_ahead_time: 2.0
    max_rotational_vel: 1.0
    min_rotational_vel: 0.4
    rotational_acc_lim: 3.2
    enable_stamped_cmd_vel: true