Profiles

At some point, one has to bind everything together. We have so far a bunch of models, and a way to specify our actual needs. What we are now looking for is a way to provide a consistent set of predefined component networks that will be the actual robot function.

This consistent set of definitions is called a profile. Profiles are defined inside a module with:

module Profiles
  profile "ProfileName" do
  end
end

This creates a ProfileName object in the enclosing module.

syskit gen profile name/of_profile

syskit gen profile rovers/localization

Naming Profiles are by convention defined under the BundleName::Profiles namespace (e.g. Rock::Profiles for the rock bundle).

Filesystem Profiles are defined in models/profiles/. The file names should be the snake_case version of the profile name (e.g. models/profiles/my_project.rb for the profile defined above). Any task context, composition or data service used in the profile file should be required first with either the using_task_library statement (for task contexts) or a simple require of the relevant file. Use syskit browse to find out what is defined where.

The first thing one can do in a profile is to give names to instance requirements. For instance, following the example above, one would probably create a pose estimation definition:

profile "Base" do
  define "pose_estimation", Compositions::PoseEstimation.
    use('orientation' => OroGen::XsensImu::Task.with_conf('default', 'high_sampling_rate'))
end

Once this definition is created, it can be referred to by using the _def suffix. For instance, one would add the corridor servoing definition from the previous examples with:

profile "Base" do
  define "pose_estimation", Compositions::PoseEstimation.
    use('orientation' => OroGen::XsensImu::Task.with_conf('default', 'high_sampling_rate'))
  define "servoing", Compositions::CorridorNavigation::CorridorServoing.
    use('pose' => pose_estimation_def)
end

Profile-wide selections

The “use” statement allows to provide selections at the level of a profile, e.g. for all the definitions in that profile. Each definition can, of course, override that profile-wide setting. For instance:

profile "Base" do
  define "pose_estimation", Compositions::PoseEstimation.
    use('orientation' => OroGen::XsensImu::Task.with_conf('default', 'high_sampling_rate'))
  use Services::Pose => pose_estimation_def
end

A common usage for this statement is to give some default configuration for a class of type contexts. For instance:

profile "Base" do
  use OroGen::PoseEstimator::Task =>
    OroGen::PoseEstimator::Task.use_conf('default', 'low_latency')
end

Reusing Profiles

Profiles are often an extension of existing “generic” profiles. For instance, Rock’s rock_ugv_nav bundle defines the RockUGVNav::Profiles::Skid4 profile that gives common definitions for any system that is a four-wheeled, skid-steered system. This is a great way to provide pre-integrated functionality for some classes of systems, leaving only the “binding to the specific platform” to the system’s integrator.

Reusing such a profile is done in two steps. First, one must require the file of the parent profile

require 'rock_ugv_nav/models/profiles/skid4.rb'

Second, one has to declare that the “child” profile must reuse the definitions from the “parent” profile.

profile "Robot do
  use_profile RockUGVNav::Profiles::Skid4
end

However, the whole purpose of reusing profiles in this case is the ability to leave some “inflexion points” in profiles, that are then selected for the particular robot it gets applied to. These inflexion points are defined in the parent profile with the ‘tag’ statement:

profile "Skid4" do
  # This profile has a tag of the provided type
  tag "wheel_control", Services::JointController
  # The tag can be used as a service would
  define "manual_control", Compositions::ManualControl.
    use('controller' => wheel_control_tag)
end

then, when reused, the child profile must say what to use for which tag:

profile "Robot" do
  use_profile RockUGVNav::Profiles::Skid4,
    'wheel_control' => OroGen::Robot::ControllerTask
end

Ensuring that all the inflexion points of a given profile are properly using tags is not done every time the profile gets loaded (it would be too costly). Instead, this is done at testing time with the it_should_be_self_contained statement (which is enabled by default if you use syskit gen).