201. Unplanned Standing

The unplanned_standing_checker detects situations where the vehicle is standing still or driving at very low speeds without a valid reason. It flags situations where the vehicle hesitates, becomes stuck, or slows down unnecessarily, even though it is safe and appropriate to continue driving. This helps detect issues in autonomous driving systems, such as excessive caution or failure to proceed, which can disrupt traffic flow.

201.0.1 Start condition

An interval starts when all of the following conditions are met:

1. The vehicle's speed falls below the configured max_speed_threshold which indicates it is standing still or near-standstill.
2. The vehicle's speed has been below the max_speed_threshold for a minimum duration debounce_start_time to avoid flagging cases where the vehicle has slowed down or stopped normally.
3. The vehicle's longitudinal acceleration is below the configured max_acceleration_threshold to avoid flagging cases where the vehicle slowed or stopped but is already starting to accelerate again.
4. None of the justification conditions are met.

201.0.2 End condition

The interval ends when any of the following conditions occur:

1. The vehicle's speed exceeds the max_speed_threshold plus a configurable tolerance speed_threshold_tolerance.
2. The vehicle's longitudinal acceleration exceeds the max_acceleration_threshold, indicating it is starting to move.
3. Any of the justification conditions are met.

201.1 Attributes

The following attributes define the behavior and characteristics of the evaluator.

201.2 Configuration parameters

The following parameters can be configured to customize the evaluator's behavior.

201.3 Metrics

The following metrics are recorded and tracked by the evaluator.

201.4 Log and Error Messages

201.5 Usage

201.5.1 How to instantiate

The unplanned_standing_checker is built into the Ego via global modifier sut_vehicle.unplanned_standing_checker. It can be instantiated for any vehicle actor.

checker unplanned_standing_checker is unplanned_standing(vehicle: actor) 
keep(unplanned_standing_checker.unplanned_standing_checker_config == \
    ftlx_global_eval_config.ego_unplanned_standing_checker_config)

201.5.2 Set parameters at instantiation time

Bind unplanned_standing_checker_config with keep(...) when you declare the checker (see the example above).

201.5.3 Define and use a custom parameter set

Customize via unplanned_standing_checker_config (defaults in ftlx_global_eval_config):

const custom_unplanned_standing_config: unplanned_standing_checker_config = new
set custom_unplanned_standing_config.max_speed_threshold = 2kph
set custom_unplanned_standing_config.debounce_start_time = 1.0s
set custom_unplanned_standing_config.max_acceleration_threshold = 0.5mpsps
set custom_unplanned_standing_config.object_detection_range = 15m
set custom_unplanned_standing_config.issue_severity = error
set custom_unplanned_standing_config.enabled = true

extend ftlx_global_eval_config:
    set ego_unplanned_standing_checker_config.max_speed_threshold = \
        custom_unplanned_standing_config.max_speed_threshold
    set ego_unplanned_standing_checker_config.debounce_start_time = \
        custom_unplanned_standing_config.debounce_start_time
    set ego_unplanned_standing_checker_config.issue_severity = \
        custom_unplanned_standing_config.issue_severity

The Ego's unplanned_standing_checker already binds config with keep(unplanned_standing_checker.unplanned_standing_checker_config == ...). For a custom checker instance, use the same keep pattern with your config const.

201.5.4 Disabling the checker

To disable the checker, set the enabled flag to false in the ego_unplanned_standing_checker_config struct.

extend ftlx_global_eval_config:
    set ego_unplanned_standing_checker_config.enabled = false

extend sut_vehicle.unplanned_standing_checker:
    on @start:
        override(unplanned_standing_checker, run_mode: freeze)

201.6 Additional information

Justification conditions

• Traffic Blocking: An object ahead within object_detection_range is stopped or moving slower than blocking_object_speed_threshold.
• Pedestrians: A person is detected ahead near the path within pedestrian_detection_range.
• Control Devices: Presence of a stop sign, yield sign, or red light within traffic_control_detection_range.
• Intersections/Roundabouts: Vehicle is navigating or yielding at junctions or roundabouts within intersection_detection_range.
• Turn Indicators: Any turn signal state other than off is active.

When the vehicle stands still without any valid justification, an interval is triggered and an issue is reported.

Implementation notes:

• Object and pedestrian detection uses vehicle.global_distance(object, closest_compound, closest_compound) to calculate distances, followed by vehicle.local_distance(object, closest_compound, closest_compound, lon) to determine if objects are ahead of the vehicle (positive local distance indicates ahead).
• Intersection detection uses map.get_route_elements_ahead_of_type(from_pos, intersection_detection_range, path, element_type) to query for internal roads and roundabout elements within the detection range.
• Traffic control device detection uses map.get_signals_on_route(vehicle.state.msp_pos.road_position, vehicle.planned_path, traffic_control_detection_range) to identify stop signs, yield signs, and traffic lights along the planned route.