Ros integration
ADORe interfacing with ROS
ADORe core functionality is provided by the system-independent c++ library libadore.
The module adore_if_ros integrates library functionality into a ROS environment:
Control processes in libadore/apps are wrapped by corresponding ROS nodes.
The communication between different ROS nodes and their corresponding control processes is transported via messages defined in adore_if_ros_msg or in the ROS standard message packages.
The module adore_if_ros defines transformations between libadore internal c++ classes and ROS messages.
The ROS parameter server provides values for the libadore internal parameters.
Control Processes and ROS Nodes
The header adore_if_ros/baseapp.h defines a base class, which is used in adore_if_ros control process nodes in order to execute and schedule the control process defined in libadore/apps.
The most important ros nodes provided by the adore_if_ros package are:
| purpopse | ROS node | description |
|---|---|---|
| planning&control | adore_checkpoint_controller_node | monitors a predefined list of manual checkpoints and enforces driver interaction before vehicle may continue over a given checkpoint |
| planning&control | adore_feedback_controller_node | tracks the current trajectory and outputs steering and acceleration actuator values |
| planning&control | adore_lfbehavior_node | lane following only tactical layer |
| planning&control | adore_lvprovider_node | computes and publishes lane following and lane change views |
| planning&control | adore_mission_controller_node | vehicle's top level state automaton responsible for switching between driving/parking and next goal location |
| planning&control | adore_monitor0_node | computes some zero order logic propositions about vehicle state, e.g. IN_COLLISION |
| planning&control | adore_navigation_node | publishes navigation information (cost to go) for lanes near vehicle |
| planning&control | adore_tactical_planner_node | requests plans from trajectory planners and selects one of the results for execution |
| planning&control | adore_trajectory_planner_lc_node | plans lane change trajectories |
| planning&control | adore_trajectory_planner_lf_node | plans lane following trajectories |
| planning&control | adore_trajectory_planner_lm_node | plans lane merge trajectories (finalization of lane change maneuver) |
| environment model | adore_mapprovider_node | publishes static lane and precedence information near vehicle |
| environment model | adore_prediction_filter | filters traffic participant motion predictions for relevance to the ego vehicle |
| environment model | adore_prediction_provider | comutes motion predictions in form of occupied space time for traffic participants detected near ego vehicle |
| environment model | area_of_effect_provider | computes area that is accessible to ego vehicle |
| environment model | speedlimit_provider | publishes speedlimit information near ego vehicle |
| environment_model | adore_crosstraffic_provider | Monitors prediction of other traffic participants and tests for intersection of cross-traffic with lane following view. In case of crosstraffic intersecting the lane following view, the nearest intersection with a feasible stopping position is published on the topic ENV/ConflictSet. The node may be extended in the future to publish also all intersection points after the first potential stopping position. |
| simulation | adore_ci_terminator_node | terminates an automatic simulation |
| simulation | adore_objectdetectionmodel_node | simulation module, which transfers information about objects near vehicle from simulation topic to ego vehicle topic |
| simulation | adore_scheduler_node | controls simulation time and advances simulation time according to slowest process |
| simulation | adore_timer_node | constrols simulation time and advances simulation time according to system time (when not paused) |
| simulation | adore_vehiclemodel_node | controls vehicle state in simulation according to scenario initialization and control inputs |
| simulation | adore_odometrymodel_node | simulates typical errors for odometry based state estimates |
| simulation | adore_localizationmodel_node | simulates typical errors for GPS-localization based state estimates |
Communication Patterns
The header adore/mad/com_patterns.h in libadore defines different abstract communication pattners, which are realized in adore_if_ros/ros_com_patterns.h with the help of ROS's publisher/subscriber principle.
Data Exchange and Topic Definition
In order to define the availability of different data sources and sinks in a system independent way, libadore makes use of an abstract factory pattern. Three abstract factories are defined in libadore for the data exchange of the environment model adore/env/afactory.h, the control functions adore/fun/afactory.h and simulation data (ground truth) adore/sim/afactory.h.
The concrete factories in adore_if_ros, envfactory.h, funfactory.h and simfactory.h define the ROS topics on which data is exchanged, the message format in which data is exchanged, the transformation method to translate between ROS messages and c++ objects and create ROS Publisher and Subscriber instances to facilitate the transport. The concrete factories reference transformation classes defined in adore_if_ros/conversions
Parameters
The abstract factory defined in adore/params/afactory.h is realized by adore_if_ros/paramsfactory.h: The concrete instances define parameter paths and names used in the ROS environment and query the parameter server.
ROS Namespaces
ADORe discriminates namespaces of multiple vehicles. Nodes, communication topics and parameters of a given vehicle are grouped in a collective namespace, for example /vehicle0/. This allows to simulate multiple autonomous vehicles in the same namespace. An arbitrary namespace can be given to each vehicle, but it must be distinct. The namespace /SIM is reserved for simulation data, meaning the ground truth of the simulation. Accordingly the topic /SIM/traffic will contain all participant's error-free states, while /vehicle0/traffic contains observations of vehicle0 about other traffic participants. Similarly /SIM/v2x contains all transmitted V2X messages and /vehicle0/v2x/incoming contains messages received by vehicle0.