126. Coverage Utilities

126.1 Traffic scenarios

126.1.1 traverse_junction()

As shown in Figure 1, a vehicle's traversal of a junction can be decomposed into three sub-phases:

• Entering the junction.
• Driving within the junction.
• Exiting the junction.

vehicle.traverse_junction() is a ready-made scenario that accomplishes just that:

import "$FTX_PACKAGES/common/osc/utils/av_utility_scenarios.osc"

extend top.main:
    a_car: vehicle
    do a_car.traverse_junction()

Executed as above, Foretify chooses a junction, creates a path that enters and exits that junction, and moves a_car along that path.

For example, a_car enters the junction at a speed of 45kph and turns left:

do a_car.traverse_junction(approach_speed: 45kph, direction: left)

In this context, direction is used to randomly pick an exiting segment relative to the entering segment. For example, in Figure 1, direction is left and corresponds to any segment within a [250..290] degree interval, measured anti-clock wise, starting from the entering segment. See section Predefined AV enumerated types in the OSC2 LRM for more details.

126.1.2 traverse_highway_junction()

Entering and exiting a highway requires traversing a special kind of road junction, complete with ramps that allow traffic to pass through the junction without interruption, as shown in Figure 2.

Figure 2 Car entering a highway

vehicle.traverse_highway_junction() is similar to vehicle.traverse_junction(). You specify where a vehicle starts the scenario (for example, driving on a highway or just entering) and where it ends (on highway or an exit ramp).

import "$FTX_PACKAGES/common/osc/utils/av_utility_scenarios.osc"

extend top.main:
    a_car: vehicle
    a_junction: highway_junction
    a_in_road: highway_entry
    a_out_road: highway
    do a_car.traverse_highway_junction(a_junction, in_road: a_in_road, out_road: a_out_road)

126.2 Coverage utilities

126.2.1 sut_behavior_coverage()

You can attach this modifier to any scenario, as shown in this example.

extend sut.to_side_on_curve:
    sut_behavior_coverage(sub_scenario: p1_sut)

The following table shows the coverage items collected by sut_behavior_coverage().

The following table shows the KPIs collected by sut_behavior_coverage().

Notes:

• TTC-related items (sut_min_ttc and _on_collision) are sampled provided that the SUT was on a collision course with another car.

• Coverage items exist in the scope of the enclosing scenario and their names are suffixed as follows:

  • If sub_scenario is not specified, then the suffix is _self.
  • If a label is passed, then the suffix is that label.

126.2.2 cover_distance_speed()

You can attach this modifier to any scenario, as shown in this example.

extend sut.lead_vehicle_and_stop:
    cover_distance_speed(other_vehicle: lead_vehicle,
        at: end, distance_lower_range: 0,
        distance_upper_range: 200, distance_unit: m, distance_every: 10,
        rel_speed_upper_range: 1, rel_speed_lower_range: -50,
        abs_speed_lower_range: 0, abs_speed_upper_range: 150)

The following table shows the parameters for cover_distance_speed().

The following table shows the metric items collected by cover_distance_speed().

126.2.3 cover_convoy_same_path()

You can attach this modifier to any scenario, as shown in this example.

extend sut.slow_neighbors:
    cover_convoy_same_path(convoy: [car1, car2, car3])

The following table shows the metric items collected by cover_convoy_same_path().

126.2.4 traverse_junction_scenario_coverage()

You can attach this modifier to any scenario using a traverse_junction scenario, as shown in this example.

extend sut.merge_at_highway_entry:
    traverse_junction_scenario_coverage(other_car: car1,
        dut_in_road: dut_in_road,
        dut_junction: dut_junction,
        dut_out_road: dut_out_road,
        other_car_in_road: car1_in_road,
        other_car_out_road: car1_out_road,
        other_car_junction: car1_junction)

The following table shows the coverage items collected by traverse_junction_scenario_coverage().

126.3 Traffic rules utilities

126.3.1 sut_at_stop_sign_check_cov()

You can attach this utility to any scenario as shown:

extend sut.sut_approach_stop_sign:
    stop_for_stop_sign_check_failure_severity: issue_severity with:
        keep(default it == error)

    sut_at_stop_sign_check_cov(
        issue_severity: stop_for_stop_sign_check_failure_severity)

126.3.2 sut_at_yield_check_cov()

You can attach this utility to any scenario as shown:

extend sut.lead_vehicle_and_slow_junction:
      dut_at_yield_check_severity: issue_severity with:
          keep(default it == error)

      dut_at_yield_check_cov(
          interceptor: car2,
          sut_junction: dut_path.junction,
          interceptor_junction: car2_path.junction,
          sut_at_yield_check_severity: dut_at_yield_check_severity,
          interceptor_min_allowed_deceleration: interceptor_min_allowed_deceleration_when_dut_at_yield)