Skip to content

Commit

Permalink
Add buff force coupler angle calculation
Browse files Browse the repository at this point in the history
  • Loading branch information
@peternewell
peternewell committed Oct 20, 2021
1 parent 780b0e8 commit 918960c
Showing 1 changed file with 85 additions and 2 deletions.
87 changes: 85 additions & 2 deletions Source/Orts.Simulation/Simulation/RollingStocks/TrainCar.cs
View file
Expand Up @@ -572,7 +572,10 @@ public Direction Direction
public float TotalWagonLateralDerailForceN;
public float LateralWindForceN;
public float WagonFrontCouplerAngleRad;
public float WagonFrontCouplerBuffAngleRad;
public float WagonRearCouplerAngleRad;
public float WagonRearCouplerBuffAngleRad;
public float CarTrackPlayM = Me.FromIn(2.0f);
public float AdjustedWagonFrontCouplerAngleRad;
public float AdjustedWagonRearCouplerAngleRad;
public float WagonFrontCouplerCurveExtM;
Expand Down Expand Up @@ -1196,6 +1199,10 @@ public virtual void UpdateTunnelForce()
///
/// Hence these calculations provide a "generic" approach to determining whether a car will derial or not.
///
/// Buff Coupler angle calculated from this publication: In-Train Force Limit Study by National Research Council Canada
///
/// https://nrc-publications.canada.ca/eng/view/ft/?id=8cc206d0-5dbd-42ed-9b4e-35fd9f8b8efb
///
/// </summary>

public void UpdateTrainDerailmentRisk(float elapsedClockSeconds)
Expand Down Expand Up @@ -1336,6 +1343,69 @@ public void UpdateTrainDerailmentRisk(float elapsedClockSeconds)
AdjustedWagonRearCouplerAngleRad = WagonRearCouplerAngleRad;
CarBehind.AdjustedWagonFrontCouplerAngleRad = CarBehind.WagonFrontCouplerAngleRad;
}

// Only process this code segment if coupler is in compression
if (CouplerForceU > 0 && CouplerSlackM < 0)
{

// Calculate Buff coupler angles. Car1 is current car, and Car2 is the car behind
// Car ahead rear coupler angle
var ThiscarCouplerlengthft = Me.ToFt(CarCouplerFaceLengthM - CarBodyLengthM) + CouplerSlackM / 2;
var CarbehindCouplerlengthft = Me.ToFt(CarBehind.CarCouplerFaceLengthM - CarBehind.CarBodyLengthM) + CouplerSlackM / 2;
var A1 = Math.Sqrt(Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBogieCentreLengthM), 2) / 4.0f);
var A2 = (Me.ToFt(CarCouplerFaceLengthM) / 2.0f) - ThiscarCouplerlengthft;
var A = (float)Math.Atan(A1 / A2);

var B = (float)Math.Asin(2.0f * Me.ToFt(CarTrackPlayM) / Me.ToFt(CarBogieCentreLengthM));
var C1 = Math.Pow(ThiscarCouplerlengthft + CarbehindCouplerlengthft, 2);

var C2_1 = Math.Sqrt(Math.Pow(Me.ToFt(CarCouplerFaceLengthM) / 2.0f - ThiscarCouplerlengthft, 2) + Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBogieCentreLengthM), 2) / 4.0f);
var C2_2 = (2.0f * Me.ToFt(CarTrackPlayM) * (Me.ToFt(CarCouplerFaceLengthM) / 2.0f - ThiscarCouplerlengthft)) / Me.ToFt(CarBogieCentreLengthM);
var C2 = Math.Pow((C2_1 + C2_2), 2);

var C3_1 = Math.Sqrt(Math.Pow(Me.ToFt(CarBehind.CarCouplerFaceLengthM) / 2.0f - CarbehindCouplerlengthft, 2) + Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBehind.CarBogieCentreLengthM), 2) / 4.0f);
var C3_2 = (2.0f * Me.ToFt(CarBehind.CarTrackPlayM) * (Me.ToFt(CarBehind.CarCouplerFaceLengthM) / 2.0f - CarbehindCouplerlengthft)) / Me.ToFt(CarBehind.CarBogieCentreLengthM);
var C3 = Math.Pow((C3_1 + C3_2), 2);

var C4 = 2.0f * (ThiscarCouplerlengthft + CarbehindCouplerlengthft) * (C2_1 + C2_2);

var C = (float)Math.Acos((C1 + C2 - C3) / C4);

WagonRearCouplerBuffAngleRad = MathHelper.ToRadians(180.0f) - A + B - C;


// Trace.TraceInformation("Buff - CarId {0} Carahead {1} A {2} B {3} C {4} 180 {5}", CarID, CarAhead.WagonRearCouplerBuffAngleRad, A, B, C, MathHelper.ToRadians(180.0f));



// This car front coupler angle
var X1 = Math.Sqrt(Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBehind.CarBogieCentreLengthM), 2) / 4.0f);
var X2 = (Me.ToFt(CarBehind.CarCouplerFaceLengthM) / 2.0f) - CarbehindCouplerlengthft;
var X = (float)Math.Atan(X1 / X2);

var Y = (float)Math.Asin(2.0f * Me.ToFt(CarBehind.CarTrackPlayM) / Me.ToFt(CarBehind.CarBogieCentreLengthM));

var Z1 = Math.Pow(ThiscarCouplerlengthft + CarbehindCouplerlengthft, 2);
var Z2_1 = Math.Sqrt(Math.Pow(Me.ToFt(CarBehind.CarCouplerFaceLengthM) / 2.0f - CarbehindCouplerlengthft, 2) + Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBehind.CarBogieCentreLengthM), 2) / 4.0f);
var Z2_2 = (2.0f * Me.ToFt(CarBehind.CarTrackPlayM) * (Me.ToFt(CarBehind.CarCouplerFaceLengthM) / 2.0f - CarbehindCouplerlengthft)) / Me.ToFt(CarBehind.CarBogieCentreLengthM);
var Z2 = Math.Pow((Z2_1 + Z2_2), 2);

var Z3_1 = Math.Sqrt(Math.Pow(Me.ToFt(CarCouplerFaceLengthM) / 2.0f - ThiscarCouplerlengthft, 2) + Math.Pow(Me.ToFt(CurrentCurveRadius), 2) - Math.Pow(Me.ToFt(CarBogieCentreLengthM), 2) / 4.0f);
var Z3_2 = (2.0f * Me.ToFt(CarTrackPlayM) * (Me.ToFt(CarCouplerFaceLengthM) / 2.0f - ThiscarCouplerlengthft)) / Me.ToFt(CarBogieCentreLengthM);
var Z3 = Math.Pow((Z3_1 + Z3_2), 2);

var Z4 = 2.0f * (ThiscarCouplerlengthft + CarbehindCouplerlengthft) * (Z2_1 + Z2_2);

var Z = (float)Math.Acos((Z1 + Z2 - Z3) / Z4);

CarBehind.WagonFrontCouplerBuffAngleRad = MathHelper.ToRadians(180.0f) - X + Y - Z;

// Trace.TraceInformation("Buff - CarId {0} Thiscar {1} A {2} B {3} C {4} 180 {5}", CarID, WagonFrontCouplerBuffAngleRad, X, Y, Z, MathHelper.ToRadians(180.0f));

// Trace.TraceInformation("Buff - CarId {0} StringThis {1} StringBehind {2} BuffThis {3} BuffAhead {4}", CarID, WagonRearCouplerAngleRad, CarBehind.WagonFrontCouplerAngleRad, WagonRearCouplerBuffAngleRad, CarBehind.WagonFrontCouplerBuffAngleRad);

}

}
else if (CarAhead != null)
{
Expand All @@ -1344,6 +1414,9 @@ public void UpdateTrainDerailmentRisk(float elapsedClockSeconds)
AdjustedWagonRearCouplerAngleRad = 0.0f;
CarBehind.AdjustedWagonFrontCouplerAngleRad = 0.0f;
WagonRearCouplerAngleRad = 0;
WagonFrontCouplerAngleRad = 0;
WagonRearCouplerBuffAngleRad = 0;
WagonFrontCouplerBuffAngleRad = 0;
CarBehind.WagonFrontCouplerAngleRad = 0;
CarAhead.WagonRearCouplerAngleRad = 0;
}
Expand Down Expand Up @@ -1424,7 +1497,16 @@ public void UpdateTrainDerailmentRisk(float elapsedClockSeconds)

if (IsPlayerTrain)
{
WagonCouplerAngleDerailRad = Math.Abs(WagonRearCouplerAngleRad);
if (CouplerForceU > 0 && CouplerSlackM < 0) // If car coupler is in compression, use the buff angle
{
WagonCouplerAngleDerailRad = Math.Abs(WagonRearCouplerBuffAngleRad);
}
else // if coupler in tension, then use tension angle
{
WagonCouplerAngleDerailRad = Math.Abs(WagonRearCouplerAngleRad);
}


var numAxles = LocoNumDrvAxles + WagonNumAxles;
var numWheels = numAxles * 2;

Expand Down Expand Up @@ -1504,7 +1586,8 @@ public void UpdateTrainDerailmentRisk(float elapsedClockSeconds)
}
else
{
DerailmentCoefficient *= 1.4f;
// DerailmentCoefficient *= 1.4f;
DerailmentCoefficient *= 2.0f;
}

var wagonAdhesion = Train.WagonCoefficientFriction;
Expand Down

0 comments on commit 918960c

Please sign in to comment.