Implementation:CARLA simulator Carla RssCheck

Knowledge Sources	CARLA
Domains	Safety, RSS, Autonomous Driving
Last Updated	2026-02-15 05:00 GMT

Overview

RssCheck is the core implementation of Responsibility-Sensitive Safety (RSS) checks for the CARLA simulator, performing safety evaluations of ego vehicle dynamics against other actors in the simulation environment.

Description

The RssCheck class implements the actual RSS checks based on the CARLA world description. It integrates with the ad-rss-lib (Intel's RSS library) and ad-map-access to perform map-based safety analysis. The implementation provides:

• Default vehicle dynamics configuration for ego vehicles, other vehicles, and pedestrians, including longitudinal/lateral acceleration limits, braking parameters, response times, and unstructured settings.
• Actor constellation callbacks that allow per-frame, per-actor configuration of RSS calculation modes and dynamics parameters.
• Route management including routing targets, road boundary enforcement, and route dropping for random rerouting.
• Ego dynamics computation on the current route, decomposing velocity and acceleration into lateral and longitudinal components relative to the route.
• RSS world model creation by matching actors to the HD map and creating RSS scenes via RssSceneCreation.
• Multi-threaded object checking via the inner RssObjectChecker class, optionally leveraging TBB for parallel processing.

Key supporting structures include EgoDynamicsOnRoute (ego vehicle state relative to the route), ActorConstellationResult (RSS configuration per actor), and ActorConstellationData (map-matched information for ego and other actors).

Usage

Use RssCheck when integrating RSS safety monitoring into autonomous driving scenarios within CARLA. It is typically instantiated and invoked by the RssSensor which calls CheckObjects each simulation tick. The class can be configured with custom actor constellation callbacks for fine-grained control over RSS parameters per actor.

Code Reference

Source Location

• Repository: CARLA
• File: LibCarla/source/carla/rss/RssCheck.cpp (1017 lines)

Signature

namespace carla {
namespace rss {

class RssCheck {
public:
  using ActorConstellationCallbackFunctionType =
      std::function<::carla::rss::ActorConstellationResult(carla::SharedPtr<ActorConstellationData>)>;

  RssCheck(float max_steering_angle);
  RssCheck(float max_steering_angle, ActorConstellationCallbackFunctionType rss_actor_constellation_callback,
           carla::SharedPtr<carla::client::Actor> const &carla_ego_actor);
  ~RssCheck();

  bool CheckObjects(carla::client::Timestamp const &timestamp,
                    carla::SharedPtr<carla::client::ActorList> const &actors,
                    carla::SharedPtr<carla::client::Actor> const &carla_ego_actor,
                    ::ad::rss::state::ProperResponse &output_response,
                    ::ad::rss::state::RssStateSnapshot &output_rss_state_snapshot,
                    ::ad::rss::situation::SituationSnapshot &output_situation_snapshot,
                    ::ad::rss::world::WorldModel &output_world_model,
                    EgoDynamicsOnRoute &output_rss_ego_dynamics_on_route);

  static ::ad::rss::world::RssDynamics GetDefaultVehicleDynamics();
  static ::ad::rss::world::RssDynamics GetDefaultPedestrianDynamics();
  static RoadBoundariesMode GetDefaultRoadBoundariesMode();

  void SetLogLevel(const spdlog::level::level_enum &log_level);
  void SetMapLogLevel(const spdlog::level::level_enum &map_log_level);
  const ::carla::rss::RoadBoundariesMode &GetRoadBoundariesMode() const;
  void SetRoadBoundariesMode(const ::carla::rss::RoadBoundariesMode &road_boundaries_mode);
  void AppendRoutingTarget(const ::carla::geom::Transform &routing_target);
  void ResetRoutingTargets();
  void DropRoute();
};

} // namespace rss
} // namespace carla

Import

#include "carla/rss/RssCheck.h"

I/O Contract

Inputs

Name	Type	Required	Description
max_steering_angle	float	Yes	Maximum steering angle of the ego vehicle in radians
timestamp	carla::client::Timestamp	Yes	Current simulation timestamp for the RSS check
actors	SharedPtr<ActorList>	Yes	List of all actors in the current simulation world
carla_ego_actor	SharedPtr<Actor>	Yes	The ego vehicle actor to evaluate RSS for
rss_actor_constellation_callback	ActorConstellationCallbackFunctionType	No	Optional callback for per-actor RSS configuration

Outputs

Name	Type	Description
output_response	ad::rss::state::ProperResponse	The proper RSS response indicating safe actions
output_rss_state_snapshot	ad::rss::state::RssStateSnapshot	Snapshot of all RSS states for all actor pairs
output_situation_snapshot	ad::rss::situation::SituationSnapshot	Snapshot of all RSS situations
output_world_model	ad::rss::world::WorldModel	The RSS world model used for the check
output_rss_ego_dynamics_on_route	EgoDynamicsOnRoute	Ego vehicle dynamics decomposed along the route
return	bool	True if the RSS check was performed successfully

Usage Examples

// Create RssCheck with default constellation callback
carla::rss::RssCheck rss_check(max_steering_angle);

// Configure road boundaries mode
rss_check.SetRoadBoundariesMode(carla::rss::RoadBoundariesMode::On);

// Add routing targets
rss_check.AppendRoutingTarget(target_transform);

// Perform RSS check
ad::rss::state::ProperResponse response;
ad::rss::state::RssStateSnapshot rss_state_snapshot;
ad::rss::situation::SituationSnapshot situation_snapshot;
ad::rss::world::WorldModel world_model;
carla::rss::EgoDynamicsOnRoute ego_dynamics;

bool success = rss_check.CheckObjects(
    timestamp, actors, ego_actor,
    response, rss_state_snapshot, situation_snapshot,
    world_model, ego_dynamics);

Related Pages

• Environment:CARLA_simulator_Carla_Simulation_Runtime
• Implementation:CARLA_simulator_Carla_RssCheck_Interface - Header file and class interface definition
• Implementation:CARLA_simulator_Carla_RssSensor - Sensor that drives the RssCheck lifecycle
• Implementation:CARLA_simulator_Carla_Vehicle_Class - Vehicle class used as ego actor