core: remove neutral section hacks to improve reliability

The current implementation of neutral ranges has at least two troublesome hacks:

- when leaving a neutral section, the train takes time to start drawing power again.
  due to the design of the current implementation, this time is converted into an
  approximate distance
- power is cut ahead of time using an announce zone, instead of having the driver
  react to the signal. this zone is there regardless of routes

These hacks bring about several bugs:

- the length of neutral section is extended by an approximation of the distance
  required to start drawing power again. This approximation is always too high
  if the train is slowing down. If the train is slowing down to a stop, it can
  get stuck in this approximated extension. This issue will vanish once this
  gets simulated over time instead.
- if a train stops inside the neutral section announce zone, it has to start
  drawing power anyway to start back up, then cut power in the neutral section.
  this behavior is very hard to emulate with the current simulation engine.
- if a sign announces a neutral section just before a switch, the announce zone
  is directional. getting this right probably means treating annonce signs as
  signals, and treat those as route dependant. This is a lot of work, and needs
  to wait until trains can react to signals (train sim v3).

These hacks were a bad idea in the first place, and the features they were meant
to implement will be a lot easier to implement once trains:

- are simulated in a causal way
- can react to signals

Author: multun

core/kt-osrd-rjs-parser/src/main/kotlin/fr/sncf/osrd/RawInfraRJSParser.kt

@@ -753,7 +753,10 @@ fun parseRJSInfra(rjsInfra: RJSInfra): RawInfra {
 
     for (neutralSection in rjsInfra.neutralSections) {
         parseNeutralRanges(builder, false, neutralSection)
-        parseNeutralRanges(builder, true, neutralSection)
+
+        // FIXME: the current implementation of neutral section announcements breaks
+        //  some use cases, see https://github.com/OpenRailAssociation/osrd/issues/7359
+        // parseNeutralRanges(builder, true, neutralSection)
     }
 
     for (speedSection in rjsInfra.speedSections) {

core/src/main/java/fr/sncf/osrd/train/RollingStock.java

@@ -233,16 +233,6 @@ public CurvesAndConditions mapTractiveEffortCurves(
         return new CurvesAndConditions(ImmutableRangeMap.copyOf(res), ImmutableRangeMap.copyOf(conditionsUsed));
     }
 
-    protected Range<Double> computeDeadSectionRange(Range<Double> neutralRange, Neutral n, Envelope maxEffortEnvelope) {
-        var endRange = neutralRange.upperEndpoint();
-        var finalSpeed = maxEffortEnvelope.interpolateSpeedLeftDir(endRange, 1);
-        double additionalRange = finalSpeed * electricalPowerStartUpTime;
-        if (n.lowerPantograph) {
-            additionalRange += finalSpeed * raisePantographTime;
-        }
-        return Range.closed(neutralRange.lowerEndpoint(), neutralRange.upperEndpoint() + additionalRange);
-    }
-
     /**
      * Returns the tractive effort curves corresponding to the electrical conditions map with
      * neutral sections
@@ -268,7 +258,8 @@ public RangeMap<Double, TractiveEffortPoint[]> addNeutralSystemTimes(
                 // estimate the distance during which the train will be coasting, due to having
                 // respected the
                 // neutral section
-                var deadSectionRange = computeDeadSectionRange(elecCondEntry.getKey(), n, maxSpeedEnvelope);
+                Range<Double> neutralRange = elecCondEntry.getKey();
+                var deadSectionRange = Range.closed(neutralRange.lowerEndpoint(), neutralRange.upperEndpoint());
                 var curveAndCondition = findTractiveEffortCurve(comfort, n);
                 if (curveAndCondition.cond.mode == null) { // The train is effectively coasting
                     newCurves.put(deadSectionRange, curveAndCondition.curve);

core/src/test/java/fr/sncf/osrd/api/StandaloneSimulationTest.java

@@ -628,6 +628,8 @@ public void testElectrificationRangesInResultWithPowerRestriction() throws IOExc
 
         ElectrificationUsage[] expected = {
             new ElectrifiedUsage("1500V", true, "O", false),
+            // the C2 power restriction reduces the power class, so no electrical profile is found
+            new ElectrifiedUsage("1500V", true, null, true),
             new NeutralUsage(true),
             new ElectrifiedUsage("25000V", true, "25000V", true),
             new ElectrifiedUsage("25000V", true, "20000V", true),

core/src/test/kotlin/fr/sncf/osrd/pathfinding/PathPropEndpointTest.kt

@@ -50,7 +50,7 @@ class PathPropEndpointTest : ApiTest() {
         assertEquals(
             parsed.electrifications,
             RangeValues(
-                listOf(1800.meters, 1950.meters),
+                listOf(1910.meters, 1950.meters),
                 listOf(Electrified("1500V"), Neutral(true), Electrified("25000V"))
             )
         )

core/src/test/kotlin/fr/sncf/osrd/pathfinding/constraints/ElectrificationConstraintsTest.kt

@@ -54,7 +54,7 @@ class ElectrificationConstraintsTest {
             // section
             Arguments.of(
                 1,
-                mutableSetOf(Pathfinding.Range(Offset<Block>(0.meters), Offset(30.meters)))
+                mutableSetOf(Pathfinding.Range(Offset<Block>(0.meters), Offset(140.meters)))
             ), // Fully corresponding electrification ranges without dead
             // sections
             Arguments.of(2, HashSet<Any>())

core/src/test/kotlin/fr/sncf/osrd/sim_infra_adapter/EnvelopeTrainPathTest.kt

@@ -205,16 +205,8 @@ class EnvelopeTrainPathTest {
         putInElectrificationMapByPowerClass(
             expected,
             800.0,
-            850.0,
-            Electrified("1500V"),
-            "A",
-            false
-        )
-        putInElectrificationMapByPowerClass(
-            expected,
-            850.0,
             960.0,
-            Neutral(true, Electrified("1500V"), true),
+            Electrified("1500V"),
             "A",
             false
         )
@@ -310,16 +302,8 @@ class EnvelopeTrainPathTest {
         putInElectrificationMapByPowerClass(
             expectedElectrificationPowerClass1,
             2_600.0,
-            2_900.0,
-            Electrified("1500V"),
-            "B",
-            false
-        )
-        putInElectrificationMapByPowerClass(
-            expectedElectrificationPowerClass1,
-            2_900.0,
             2_910.0,
-            Neutral(false, Electrified("1500V"), true),
+            Electrified("1500V"),
             "B",
             false
         )
@@ -372,16 +356,8 @@ class EnvelopeTrainPathTest {
         putInElectrificationMapByPowerClass(
             expectedElectrificationPowerClass2,
             2_700.0,
-            2_900.0,
-            Electrified("1500V"),
-            "C",
-            false
-        )
-        putInElectrificationMapByPowerClass(
-            expectedElectrificationPowerClass2,
-            2_900.0,
             2_910.0,
-            Neutral(false, Electrified("1500V"), true),
+            Electrified("1500V"),
             "C",
             false
         )
@@ -422,11 +398,7 @@ class EnvelopeTrainPathTest {
                     Direction.INCREASING,
                     ImmutableRangeMap.Builder<Double, Electrification>()
                         .put(Range.closedOpen(0.0, 300.0), NonElectrified())
-                        .put(Range.closedOpen(300.0, 1_350.0), Electrified("1500V"))
-                        .put(
-                            Range.closedOpen(1_350.0, 1_460.0),
-                            Neutral(true, Electrified("1500V"), true)
-                        )
+                        .put(Range.closedOpen(300.0, 1_460.0), Electrified("1500V"))
                         .put(
                             Range.closedOpen(1_460.0, 1_500.0),
                             Neutral(true, Electrified("1500V"), false)
@@ -442,11 +414,7 @@ class EnvelopeTrainPathTest {
                     ImmutableRangeMap.Builder<Double, Electrification>()
                         .put(Range.closedOpen(0.0, 350.0), Electrified("25000V"))
                         .put(Range.closedOpen(350.0, 450.0), NonElectrified())
-                        .put(Range.closedOpen(450.0, 1_450.0), Electrified("1500V"))
-                        .put(
-                            Range.closedOpen(1_450.0, 1_460.0),
-                            Neutral(false, Electrified("1500V"), true)
-                        )
+                        .put(Range.closedOpen(450.0, 1_460.0), Electrified("1500V"))
                         .put(
                             Range.closedOpen(1_460.0, 1_600.0),
                             Neutral(false, Electrified("1500V"), false)