the Robot Construction Kit
This tutorial will show you how to use configuration files within bundles and how to apply configurations to compositions and components.
Configuration files are YAML files in which the properties are listed and some values are assigned to them. For instance, when looking at the interface of the random motion generator:
[...er/bundles/tutorial]% rock-inspect --show-tasks tut_brownian ========================================================== Task name: tut_brownian::Task defined in tut_brownian ---------------------------------------------------------- ------- tut_brownian::Task ------ no documentation defined for this task context model subclass of RTT::TaskContext (the superclass elements are displayed below) Ports [out]cmd:/base/MotionCommand2D [out]state:/int32_t No dynamic ports Properties max_angular_speed:/double, default: 0.314159265358979 max_speed:/double, default: 1.5 min_speed:/double, default: 0.5 straight_duration:/double, default: 5 turn_duration:/double, default: 5 No attributes No operations
We have 5 properties that configure our component. Let’s use a non-default value for the max_speed.
First, let’s use a tool to generate a file filled with default values. To do this, we first create configuration directory for our oroGen components in bundles/tutorials and then use the tool oroconf to generate default configuration files with the option:
mkdir -p config/orogen
oroconf extract tut_brownian::Task --save config/orogen/
The YAML files in config/orogen/ must follow the modelname.yml template to be picked up by the system. In this case, the generated file has automatically be called tut_brownian::Task.yml
Have a look at the freshly created config/orogen/tut_brownian::Task.yml, and compare it to the values reported by rock-inspect.
Start a controller with ‘random’ deployed by default
rock-roby run scripts/rockRoby3.rb random
Have a look at the configuration values:
In the configuration files, one can define multiple configuration blocks by giving them names. Let’s add two new configurations. Change config/orogen/tut_brownian::Task.yml to look like:
--- name:default # no documentation available for this property max_angular_speed: 0.314159265358979 # no documentation available for this property max_speed: 1.5 # no documentation available for this property min_speed: 0.5 # no documentation available for this property straight_duration: 5.0 # no documentation available for this property turn_duration: 5.0 --- name:slow max_speed: 0.5 min_speed: 0 --- name:fast max_speed: 4 min_speed: 2
The general concept here is that, by default, the ‘default’ configuration is applied. Configuration overlays can then be selected, where the parameters defined by some sections are overriden by other. For instance, the ‘default,slow’ configuration contains all values from default except for max_speed and min_speed that are set to the values in the ‘slow’ configuration.
When defining a deployable task or adding it, a configuration is selected with
define('random', Cmp::RockControl).use(TutBrownian::Task.use_conf('default', 'slow'))
One can also define configurations on compositions. Composition configurations forward configurations to children. For instance, the following declaration announces that Cmp::RockControl has a ‘slow’ configuration, in which the ‘cmd’ child (the Srv::CommandGenerator) should be configured with ‘default,slow’. The configuration of the RockTutorialControl task is left open.
composition 'RockControl' do # Any command generator add Srv::CommandGenerator, :as => "cmd" # And one rock add RockTutorial::RockTutorialControl, :as => "rock" # Create any unique possible connection. If ambiguities # exist, an error is generated autoconnect conf 'slow', 'cmd' => ['default', 'slow'] end
Advanced The configurations are part of the deployment constraints. This means, in practice that if two deployments request a task to be deployed with two different configurations, the deployment will fail.
There is, for now, no ways to select configurations from the shell.
In this tutorial you learned:
The next tutorial will introduce you to handling some more complex setups.