core: stdcm: set a min speed for engineering allowance check

We used to consider that we can add any amount of time if the train can basically stop, but this was too optimistic Signed-off-by: Eloi Charpentier <eloi.charpentier.42@gmail.com>
OpenRailAssociation · Jan 8, 2025 · 79b87f4 · 79b87f4
1 parent cae4d30
commit 79b87f4
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/EngineeringAllowanceManager.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/EngineeringAllowanceManager.kt
@@ -141,13 +141,21 @@ class EngineeringAllowanceManager(private val graph: STDCMGraph) {
                     //          /
                     // We need to set the first constant speed part to 0
                     // so that we can use it as floor constraint
+
+                    // The min speed value isn't entirely trivial to determine:
+                    // We need it to be strictly positive to avoid NaN issues,
+                    // but we're also too optimistic with allowance possibility
+                    // when we let it get close to 0. But if it's too high, we miss
+                    // out on solutions.
+                    // So this is a magic value that could be tweaked if needed.
+                    val minSpeed = 1.0
                     builder.addPart(
                         EnvelopePart.generateTimes(
                             mutableListOf<SelfTypeHolder?>(
                                 EnvelopeProfile.CONSTANT_SPEED,
                             ),
                             doubleArrayOf(0.0, lastAccelerationPosition),
-                            doubleArrayOf(1e-5, 1e-5) // >0 to avoid NaN time delta
+                            doubleArrayOf(minSpeed, minSpeed)
                         )
                     )
                 }
@@ -168,7 +176,6 @@ class EngineeringAllowanceManager(private val graph: STDCMGraph) {
             if (slowdownPartBuilder.stepCount() > 1)
                 slowdownBuilder.addPart(slowdownPartBuilder.build())
             val slowestEnvelope = slowdownBuilder.build()
-            if (slowestEnvelope.minSpeed <= 1.0) return Double.POSITIVE_INFINITY
             return slowestEnvelope.totalTime
         } catch (e: OSRDError) {
             // We can be pessimistic: simulation error = no allowance

diff --git a/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/PostProcessingSimulation.kt b/core/src/main/kotlin/fr/sncf/osrd/stdcm/graph/PostProcessingSimulation.kt
@@ -407,11 +407,14 @@ private fun handlePostProcessingConflict(
     updatedTimeData: TimeData,
     fixedPoints: TreeSet<FixedTimePoint>,
     conflictOffset: Offset<TravelledPath>,
-    isMareco: Boolean
+    isMareco: Boolean,
 ): Envelope {
     postProcessingLogger.error(
         "Conflicts detected in post-processing, mismatch with the exploration data"
     )
+    postProcessingLogger.error(
+        "NOTE: look through the logs for allowance issues, they may cause mismatches."
+    )
     val conflictTime = fixedPoints.first { it.offset == conflictOffset }.time
     postProcessingLogger.info(
         "    conflict happened at offset=$conflictOffset/${maxSpeedEnvelope.endPos.toInt()} " +