tests: add ETCS LoA (slowdown) tests on speed-space chart

Signed-off-by: Pierre-Etienne Bougué <[email protected]>

Author: bougue-pe

tests/tests/test_train_schedule.py

@@ -206,10 +206,10 @@ def test_etcs_schedule_result_stop_brake_from_mrsp(etcs_scenario: Scenario, etcs
                 "rolling_stock_name": etcs_rolling_stock_name,
                 "start_time": "2024-01-01T07:00:00Z",
                 "path": [
-                    {"id": "zero", "track": "TA0", "offset": 862000},
-                    {"id": "first", "track": "TD0", "offset": 17156000},
-                    {"id": "second", "track": "TH1", "offset": 1177000},
-                    {"id": "last", "track": "TH1", "offset": 3922000},
+                    {"id": "zero", "track": "TA0", "offset": 862_000},
+                    {"id": "first", "track": "TD0", "offset": 1_7156_000},
+                    {"id": "second", "track": "TH1", "offset": 1_177_000},
+                    {"id": "last", "track": "TH1", "offset": 3_922_000},
                 ],
                 "schedule": [
                     {"at": "zero", "stop_for": "P0D"},
@@ -283,17 +283,187 @@ def test_etcs_schedule_result_stop_brake_from_mrsp(etcs_scenario: Scenario, etcs
     )
     offset_start_second_brake = 40_663_532
     speed_before_second_brake = _get_current_or_next_speed_at(simulation_final_output, offset_start_second_brake)
-    assert abs(speed_before_second_brake - kph2ms(141.984)) < 1e-2
+    assert abs(speed_before_second_brake - kph2ms(141.9984)) < 1e-2
     assert (
         _get_current_or_next_speed_at(simulation_final_output, offset_start_second_brake + 1)
         < speed_before_second_brake
     )
 
 
+def test_etcs_schedule_result_slowdowns(etcs_scenario: Scenario, etcs_rolling_stock: int):
+    rolling_stock_response = requests.get(EDITOAST_URL + f"light_rolling_stock/{etcs_rolling_stock}")
+    etcs_rolling_stock_name = rolling_stock_response.json()["name"]
+    ts_response = requests.post(
+        f"{EDITOAST_URL}timetable/{etcs_scenario.timetable}/train_schedule/",
+        json=[
+            {
+                "train_name": "slowdowns to respect MRSP and safe approach speed",
+                "labels": [],
+                "rolling_stock_name": etcs_rolling_stock_name,
+                "start_time": "2024-01-01T07:00:00Z",
+                "path": [
+                    {"id": "zero", "track": "TA0", "offset": 0},
+                    {"id": "last", "track": "TH1", "offset": 5_000_000},
+                ],
+                "schedule": [
+                    {"at": "zero", "stop_for": "P0D"},
+                    {"at": "last", "stop_for": "P0D"},
+                ],
+                "margins": {"boundaries": [], "values": ["0%"]},
+                "initial_speed": 0,
+                "comfort": "STANDARD",
+                "constraint_distribution": "STANDARD",
+                "speed_limit_tag": "foo",
+                "power_restrictions": [],
+            }
+        ],
+    )
+
+    schedule = ts_response.json()[0]
+    schedule_id = schedule["id"]
+    ts_id_response = requests.get(f"{EDITOAST_URL}train_schedule/{schedule_id}/")
+    ts_id_response.raise_for_status()
+    simu_response = requests.get(
+        f"{EDITOAST_URL}train_schedule/{schedule_id}/simulation?infra_id={etcs_scenario.infra}"
+    )
+    simulation_final_output = simu_response.json()["final_output"]
+
+    assert len(simulation_final_output["positions"]) == len(simulation_final_output["speeds"])
+
+    # To debug this test: please add a breakpoint then use front to display speed-space chart
+    # (activate Context for Slopes and Speed limits).
+
+    # Check that the curves does respect Ends of Authority (EoA = stops), and that there is an
+    # acceleration then deceleration in between (maintain speed when reach the MRSP).
+    # This is the case here because MRSP is not doing ups-and-downs.
+    final_stop_offset = 47_000_000
+    stop_offsets = [
+        0,
+        final_stop_offset,
+    ]
+
+    # Check null speed at stops
+    for stop_offset in stop_offsets:
+        assert _get_current_or_next_speed_at(simulation_final_output, stop_offset) == 0
+
+    # Check only one acceleration then only one deceleration between begin and end
+    for offset_index in range(1, len(stop_offsets) - 1):
+        accelerating = True
+        prev_speed = 0
+        start_pos_index = bisect.bisect_left(simulation_final_output["positions"], stop_offsets[offset_index - 1])
+        end_pos_index = bisect.bisect_left(simulation_final_output["positions"], stop_offsets[offset_index])
+        for pos_index in range(start_pos_index, end_pos_index):
+            current_speed = simulation_final_output["speeds"][pos_index]
+            if accelerating:
+                if prev_speed > current_speed:
+                    accelerating = False
+            else:
+                assert prev_speed >= current_speed
+            prev_speed = current_speed
+
+    # Check that the braking curves for limits of Authority (LoA = slowdowns of the MRSP) start and end at the
+    # expected offset.
+    # Also check a bending point for the first curve (where Guidance curve's influence stops).
+    # Note: the end of the braking is upstream the actual MRSP slowdown's target as per the offset applied to
+    # LoA braking curves.
+
+    # First slowdown
+    offset_start_brake_288_to_142 = 35_051_929
+    speed_before_brake_288_to_142 = _get_current_or_next_speed_at(
+        simulation_final_output, offset_start_brake_288_to_142
+    )
+    assert abs(speed_before_brake_288_to_142 - kph2ms(288)) < 1e-2
+    assert (
+        _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_288_to_142 + 1)
+        < speed_before_brake_288_to_142
+    )
+
+    offset_bending_guidance_point = 38_176_509
+    speed_at_bending_guidance_point = _get_current_or_next_speed_at(
+        simulation_final_output, offset_bending_guidance_point
+    )
+    assert abs(speed_at_bending_guidance_point - kph2ms(235.901_491_880_851_1)) < 1e-2
+
+    offset_end_brake_288_to_142 = 40_724_374
+    speed_after_brake_288_to_142 = _get_current_or_next_speed_at(simulation_final_output, offset_end_brake_288_to_142)
+    assert (
+        _get_current_or_prev_speed_at(simulation_final_output, offset_end_brake_288_to_142 - 1)
+        > speed_after_brake_288_to_142
+    )
+    assert abs(speed_after_brake_288_to_142 - kph2ms(141.9984)) < 1e-2
+
+    # Second slowdown
+    offset_start_brake_142_to_120 = 44_313_934
+    speed_before_brake_142_to_120 = _get_current_or_next_speed_at(
+        simulation_final_output, offset_start_brake_142_to_120
+    )
+    assert abs(speed_before_brake_142_to_120 - kph2ms(141.9984)) < 1e-2
+    assert (
+        _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_142_to_120 + 1)
+        < speed_before_brake_142_to_120
+    )
+    offset_end_brake_142_to_120 = 44_848_053
+    speed_after_brake_142_to_120 = _get_current_or_next_speed_at(simulation_final_output, offset_end_brake_142_to_120)
+    assert (
+        _get_current_or_prev_speed_at(simulation_final_output, offset_end_brake_142_to_120 - 1)
+        > speed_after_brake_142_to_120
+    )
+    assert abs(speed_after_brake_142_to_120 - kph2ms(111.9996)) < 1e-2
+
+    # Slowdown for Safety Speed stop: should probably disappear for ETCS at some point
+    offset_start_brake_120_to_30 = 45_536_480
+    speed_before_brake_120_to_30 = _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_120_to_30)
+    assert abs(speed_before_brake_120_to_30 - kph2ms(111.9996)) < 1e-2
+    assert (
+        _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_120_to_30 + 1)
+        < speed_before_brake_120_to_30
+    )
+    offset_end_brake_120_to_30 = 46_554_045
+    speed_after_brake_120_to_30 = _get_current_or_next_speed_at(simulation_final_output, offset_end_brake_120_to_30)
+    assert (
+        _get_current_or_prev_speed_at(simulation_final_output, offset_end_brake_120_to_30 - 1)
+        > speed_after_brake_120_to_30
+    )
+    assert abs(speed_after_brake_120_to_30 - kph2ms(29.9988)) < 1e-2
+
+    # Slowdown for short slip stop: should probably disappear for ETCS at some point
+    offset_start_brake_30_to_10 = 46_597_240
+    speed_before_brake_30_to_10 = _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_30_to_10)
+    assert abs(speed_before_brake_30_to_10 - kph2ms(29.9988)) < 1e-2
+    assert (
+        _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_30_to_10 + 1)
+        < speed_before_brake_30_to_10
+    )
+    offset_end_brake_30_to_10 = 46_748_388
+    speed_after_brake_30_to_10 = _get_current_or_next_speed_at(simulation_final_output, offset_end_brake_30_to_10)
+    assert (
+        _get_current_or_prev_speed_at(simulation_final_output, offset_end_brake_30_to_10 - 1)
+        > speed_after_brake_30_to_10
+    )
+    assert abs(speed_after_brake_30_to_10 - kph2ms(10.0008)) < 1e-2
+
+    # Final slowdown: EoA (complete stop) braking curve is applied
+    offset_start_brake_10_to_0 = 46_953_914
+    speed_before_brake_10_to_0 = _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_10_to_0)
+    assert abs(speed_before_brake_10_to_0 - kph2ms(10.0008)) < 1e-2
+    assert (
+        _get_current_or_next_speed_at(simulation_final_output, offset_start_brake_10_to_0 + 1)
+        < speed_before_brake_10_to_0
+    )
+
+
 def kph2ms(kmh_speed: float) -> float:
     return kmh_speed / 3.6
 
 
 def _get_current_or_next_speed_at(simulation_final_output: Dict[str, Any], position: int) -> int:
     idx = bisect.bisect_left(simulation_final_output["positions"], position)
     return simulation_final_output["speeds"][idx]
+
+
+def _get_current_or_prev_speed_at(simulation_final_output: Dict[str, Any], position: int) -> int:
+    idx = bisect.bisect_left(simulation_final_output["positions"], position)
+    if simulation_final_output["positions"][idx] > position and idx > 0:
+        return simulation_final_output["speeds"][idx - 1]
+    else:
+        return simulation_final_output["speeds"][idx]