public static QuadraticSpeedDistanceCurve Build_A_Safe_Backward(AccelerationSpeedDistanceSurface A_V_D, FlatSpeedDistanceCurve MRSP)
{
if (debug)
{
Log.InfoFormat("#######################################################");
Log.InfoFormat("## Build_A_Safe_Backward_Surface#######################");
Log.InfoFormat("#######################################################");
}
int debugging_counter = 0;
QuadraticSpeedDistanceCurve result = new QuadraticSpeedDistanceCurve();
/***********************************************************
The ending point is the first point in the MRSP
***********************************************************/
SiDistance end_position = MRSP[0].X.X0;
/***********************************************************
Go forward in the MRSP until we find the point with
minimal speed. This shall be our starting point
**********************************************************/
SiDistance current_position = SiDistance.Zero;
SiSpeed current_speed = SiSpeed.MaxValue;
if (debug)
Log.DebugFormat(" Search the position of the minimal speed in the MRSP");
for (int i = 0; i < MRSP.SegmentCount; i++)
{
ConstantCurveSegment<SiDistance, SiSpeed> segment = MRSP[i];
if (segment.Y < current_speed)
{
current_speed = segment.Y;
current_position = segment.X.X1;
if (debug)
Log.DebugFormat(" new start position V={0,7:F2} at={1,7:F2} ", current_speed.ToUnits(), current_position.ToUnits());
}
}
if (debug)
Log.DebugFormat(" end position is at={0,7:F2} ", end_position.ToUnits());
/*************************************************************************/
/* Starting from the right side of curves, go back to the left side. */
/* Build small curves arcs where the acceleration is constant on each one*/
/*************************************************************************/
while (current_position > end_position)
{
if (debug)
{
Log.DebugFormat("#######################################################");
Log.DebugFormat("### Loop {0} #########################################", debugging_counter);
Log.DebugFormat("#######################################################");
}
/************************************************************
Based on current speed and position, search on wich tile
of A_V_D tile we are
***********************************************************/
SurfaceTile current_tile = A_V_D.GetTileAt(current_speed + new SiSpeed(0.01), current_position - new SiDistance(0.1));
SiAcceleration current_acceleration = current_tile.V.Y;
/***************************************************************************/
/* If at previous loop wi did 'hit' the vertical part of the MRSP,
we might have a speed above the current MRSP segment.*/
/***************************************************************************/
if (current_speed > MRSP.GetValueAt(current_position - new SiDistance(0.1)))
{
current_speed = MRSP.GetValueAt(current_position - new SiDistance(0.1));
}
/*******************************************************************
We build a quadratic arc with current train position, speed
and acceleration. The arc domain [0..current_position] is not valid yet.
We must find out the domain left limit.
*****************************************************************/
QuadraticCurveSegment current_curve = new QuadraticCurveSegment(SiDistance.Zero,
current_position,
current_acceleration,
current_speed,
current_position);
if (debug)
{
Log.DebugFormat(" current_acceleration = {0,7:F2} from a_tile {1}", current_acceleration.ToUnits(), current_tile.ToString());
Log.DebugFormat(" current_speed = {0,7:F2} ", current_speed.ToUnits());
Log.DebugFormat(" current_position = {0,7:F2} ", current_position.ToUnits());
Log.DebugFormat(" --> current_curve = {0} ", current_curve.ToString());
}
/********************************************************************/
/* The current_curve may 'hit' one of these 4 items:
1) The upper border of the tile (because of a new acceleration)
2) The left border of the tile (because of a gradient?)
3) A vertical segment of the MRSP
4) An horizontal segment of the MRSP
Text all of them and update the next_position accordingly.
*************************************************************************/
SiDistance next_position = SiDistance.Zero;
/* 1) The distance at wich our temporary arc intersects the top (V2) segment of the AVD tile */
{
SiDistance d = current_curve.IntersectAt(current_tile.V.X.X1);
if (debug)
Log.DebugFormat(" intersection with tile (V_TOP) at {0,7:F2} ", d.ToUnits());
if (d >= next_position)
{
if (debug)
Log.DebugFormat(" --> case_1 next_position {0,7:F2} -> {1,7:F2}", next_position.ToUnits(), d.ToUnits());
next_position = d;
}
}
/* 2) The distance at wich our temporary arc intersects the left (D0) segment of the AVD tile */
{
SiDistance d = current_tile.D.X.X0;
if (debug)
Log.DebugFormat(" intersection with tile (D0) at {0,7:F2} ", d.ToUnits());
if (d >= next_position)
{
if (debug)
Log.DebugFormat(" --> case_2 next_position {0,7:F2} -> {1,7:F2}", next_position.ToUnits(), d.ToUnits());
next_position = d;
}
}
/*Since the MRSP is continous, the following cannot fail. */
ConstantCurveSegment<SiDistance, SiSpeed> speed_limit_here = MRSP.Intersect(current_position - new SiDistance(0.1), current_curve);
if (debug)
Log.DebugFormat(" MRSP segment {0} ", speed_limit_here.ToString());
/* 3) Do we hit the vertical segment of the MRSP ? */
{
if (speed_limit_here.X.X0 >= next_position)
{
if (debug)
Log.DebugFormat(" --> case_3 next_position {0,7:F2} -> {1,7:F2}", next_position.ToUnits(), speed_limit_here.X.X0.ToUnits());
next_position = speed_limit_here.X.X0;
}
}
/* 4) Do we hit the horizontal segment of the MRSP */
{
if (current_speed + new SiSpeed(0.01) < speed_limit_here.Y)
{
SiDistance d = current_curve.IntersectAt(speed_limit_here.Y);
if (d >= next_position)
{
if (debug)
Log.DebugFormat(" --> case_4a next_d {0,7:F2} -> {1,7:F2}", next_position.ToUnits(), d.ToUnits());
next_position = d;
}
}
else
{
if (debug)
Log.DebugFormat(" --> case_4b next_acc_0 {0,7:F2} -> {1,7:F2}", next_position.ToUnits(), speed_limit_here.X.X0.ToUnits());
current_acceleration = SiAcceleration.Zero;
next_position = speed_limit_here.X.X0;
}
}
/* Finally we can add the segment because next_position has been computed. */
result.Add(next_position, current_position, current_acceleration, current_speed, current_position);
result.Dump("result so far ");
/* Next loop starts from our new position.
We do not need to update current_acceleration because
it is done at the beginning of the loop*/
current_position = next_position;
current_speed = result.GetValueAt(current_position);
/*************************************************************/
/* If this exception is thrown, you'd better call Juan */
/*************************************************************/
if (debugging_counter++ > 200)
{
throw new Exception("Algorithm is broken");
}
}
return result;
}
/// <summary>
/// Finds the tile edge that is intersected in the chosen direction
/// </summary>
/// <param name="current_tile"></param>
/// <param name="current_curve"></param>
/// <param name="dir"></param>
/// <returns></returns>
private static SiDistance Tile_Intersect(SiDistance current_position, SurfaceTile current_tile,
QuadraticCurveSegment current_curve, BrakingCurveDirectionEnum dir)
{
SiDistance result = SiDistance.Zero;
SiDistance SpdEdge = Speed_Edge_Location(current_tile, current_curve, dir);
SiDistance DistEdge = Distance_Edge(current_tile, dir);
result = Closest_To(current_position, DistEdge, SpdEdge);
return result;
}
/******************************************************************************************************/
protected void Emit_Quadratic_Segment(StreamWriter swd, QuadraticCurveSegment aSegment, SiSpeed v_offset, SiDistance d_offset)
{
SiDistance d0 = aSegment.X.X0;
SiDistance d1 = aSegment.X.X1;
Emit_d_V(swd, d0 + d_offset, aSegment.Get(d0) + v_offset);
if (d1 - d0 > SiDistance.One)
{
SiDistance delta = SiDistance.One;
SiDistance d = d0 + delta;
do
{
Emit_d_V(swd, d + d_offset, aSegment.Get(d) + v_offset);
d += delta;
} while (d < d1);
}
Emit_d_V(swd, d1 + d_offset, aSegment.Get(d1) + v_offset);
}
/// <summary>
/// Provides the distance at which the curve intersects the horizontal edge of the tile in the given direction
/// </summary>
/// <param name="current_tile"></param>
/// <param name="current_curve"></param>
/// <param name="dir"></param>
/// <returns></returns>
private static SiDistance Speed_Edge_Location(SurfaceTile current_tile, QuadraticCurveSegment current_curve,
BrakingCurveDirectionEnum dir)
{
SiDistance result = SiDistance.Zero;
SiSpeed limit = SiSpeed.Zero;
switch (dir)
{
case BrakingCurveDirectionEnum.Backwards:
limit = current_tile.V.X.X1;
break;
case BrakingCurveDirectionEnum.Forwards:
limit = current_tile.V.X.X0;
break;
}
result = current_curve.IntersectAt(limit);
return result;
}
/// <summary>
/// Provides the distance limit of a tile in the requested direction
/// </summary>
/// <param name="current_tile"></param>
/// <param name="dir"></param>
/// <returns></returns>
private static SiDistance Distance_Edge(QuadraticCurveSegment current_curve, BrakingCurveDirectionEnum dir)
{
SiDistance result = SiDistance.Zero;
switch (dir)
{
case BrakingCurveDirectionEnum.Backwards:
result = current_curve.X.X0;
break;
case BrakingCurveDirectionEnum.Forwards:
result = current_curve.X.X1;
break;
}
return result;
}
/// <summary>
/// Method to return the curve segment at the current location and speed, going in the specified direction.
/// </summary>
/// <param name="current_tile"></param>
/// <param name="current_position"></param>
/// <param name="current_speed"></param>
/// <param name="MRSP"></param>
/// <param name="dir"></param>
/// <returns></returns>
private static QuadraticCurveSegment Build_One_Curve_Segment(SurfaceTile current_tile,
SiDistance current_position,
SiSpeed current_speed,
FlatSpeedDistanceCurve MRSP,
BrakingCurveDirectionEnum dir)
{
SiAcceleration current_acceleration = current_tile.V.Y;
SiDistance MRSP_end = MRSP[MRSP.SegmentCount - 1].X.X1;
SiDistance curve_start = new SiDistance();
SiDistance curve_end = new SiDistance();
switch (dir)
{
case BrakingCurveDirectionEnum.Backwards:
curve_start = SiDistance.Zero;
curve_end = current_position;
break;
case BrakingCurveDirectionEnum.Forwards:
curve_start = current_position;
curve_end = MRSP_end;
break;
}
QuadraticCurveSegment current_curve = new QuadraticCurveSegment(curve_start,
curve_end,
current_acceleration,
current_speed,
current_position);
if (debug)
{
Log.DebugFormat(" current_acceleration = {0,7:F2} from a_tile {1}", current_acceleration.ToUnits(),
current_tile.ToString());
Log.DebugFormat(" current_speed = {0,7:F2} ", current_speed.ToUnits());
Log.DebugFormat(" current_position = {0,7:F2} ", current_position.ToUnits());
Log.DebugFormat(" --> current_curve = {0} ", current_curve.ToString());
}
/********************************************************************/
/* The current_curve may 'hit' one of these 4 items:
1) The upper border of the tile (because of a new acceleration)
2) The left border of the tile (because of a gradient?)
3) A vertical segment of the MRSP
4) An horizontal segment of the MRSP
Text all of them and update the next_position accordingly.
*************************************************************************/
SiDistance next_position = SiDistance.Zero;
/* The distance at which our temporary arc intersects a segment of the AVD tile */
{
next_position = Tile_Intersect(current_position, current_tile, current_curve, dir);
}
/* The MRSP checks only need to be performed if the curve is being computed backwards */
if (dir == BrakingCurveDirectionEnum.Backwards)
{
/*Since the MRSP is continous, the following cannot fail. */
ConstantCurveSegment<SiDistance, SiSpeed> speed_limit_here =
MRSP.Intersect(current_position - new SiDistance(0.1), current_curve);
if (debug)
Log.DebugFormat(" MRSP segment {0} ", speed_limit_here.ToString());
/* 3) Do we hit the vertical segment of the MRSP ? */
{
next_position = IntersectMRSPSpeed(next_position, speed_limit_here);
}
/* 4) Do we hit the horizontal segment of the MRSP */
{
if (current_speed + new SiSpeed(0.01) < speed_limit_here.Y)
{
SiDistance d = current_curve.IntersectAt(speed_limit_here.Y);
if (d >= next_position)
{
if (debug)
Log.DebugFormat(" --> case_4a next_d {0,7:F2} -> {1,7:F2}",
next_position.ToUnits(), d.ToUnits());
next_position = d;
}
}
else
{
if (debug)
Log.DebugFormat(" --> case_4b next_acc_0 {0,7:F2} -> {1,7:F2}", next_position.ToUnits(),
speed_limit_here.X.X0.ToUnits());
current_acceleration = SiAcceleration.Zero;
next_position = speed_limit_here.X.X0;
}
}
}
SiDistance result_start = new SiDistance();
SiDistance result_end = new SiDistance();
switch (dir)
{
case BrakingCurveDirectionEnum.Backwards:
result_start = next_position;
result_end = current_position;
break;
case BrakingCurveDirectionEnum.Forwards:
result_start = current_position;
result_end = next_position;
break;
}
QuadraticCurveSegment result = new QuadraticCurveSegment(result_start,
result_end,
current_acceleration,
current_speed,
current_position);
return result;
}
/// <summary>
/// Provides the graph of this function if it has been statically defined
/// </summary>
/// <param name="context">the context used to create the graph</param>
/// <returns></returns>
public override Graph createGraph(Interpreter.InterpretationContext context, Parameter parameter)
{
Graph retVal = null;
Graph MRSPGraph = null;
Function speedRestriction = context.findOnStack(SpeedRestrictions).Value as Function;
if (speedRestriction != null)
{
Parameter p = (Parameter)speedRestriction.FormalParameters[0];
int token = context.LocalScope.PushContext();
context.LocalScope.setGraphParameter(p);
MRSPGraph = createGraphForValue(context, context.findOnStack(SpeedRestrictions).Value, p);
context.LocalScope.PopContext(token);
}
if (MRSPGraph != null)
{
Function deceleratorFactor = context.findOnStack(DecelerationFactor).Value as Function;
if (deceleratorFactor != null)
{
Surface DecelerationSurface = deceleratorFactor.createSurface(context);
if (DecelerationSurface != null)
{
FlatSpeedDistanceCurve MRSPCurve = MRSPGraph.FlatSpeedDistanceCurve(MRSPGraph.ExpectedEndX());
AccelerationSpeedDistanceSurface accelerationSurface = DecelerationSurface.createAccelerationSpeedDistanceSurface(double.MaxValue, double.MaxValue);
QuadraticSpeedDistanceCurve BrakingCurve = null;
try
{
BrakingCurve = EtcsBrakingCurveBuilder.Build_A_Safe_Backward(accelerationSurface, MRSPCurve);
}
catch (System.Exception e)
{
retVal = new Graph();
retVal.addSegment(new Graph.Segment(0, double.MaxValue, new Graph.Segment.Curve(0, 0, 0)));
}
if (BrakingCurve != null)
{
retVal = new Graph();
// TODO : Remove the distinction between linear curves and quadratic curves
bool isLinear = true;
for (int i = 0; i < BrakingCurve.SegmentCount; i++)
{
QuadraticCurveSegment segment = BrakingCurve[i];
if (segment.A.ToUnits() != 0.0 || segment.V0.ToUnits() != 0.0)
{
isLinear = false;
break;
}
}
for (int i = 0; i < BrakingCurve.SegmentCount; i++)
{
QuadraticCurveSegment segment = BrakingCurve[i];
Graph.Segment newSegment;
if (isLinear)
{
newSegment = new Graph.Segment(
segment.X.X0.ToUnits(),
segment.X.X1.ToUnits(),
new Graph.Segment.Curve(0.0, segment.V0.ToSubUnits(SiSpeed_SubUnits.KiloMeter_per_Hour), 0.0));
}
else
{
newSegment = new Graph.Segment(
segment.X.X0.ToUnits(),
segment.X.X1.ToUnits(),
new Graph.Segment.Curve(
segment.A.ToSubUnits(SiAcceleration_SubUnits.Meter_per_SecondSquare),
segment.V0.ToSubUnits(SiSpeed_SubUnits.KiloMeter_per_Hour),
segment.D0.ToSubUnits(SiDistance_SubUnits.Meter)
)
);
}
retVal.addSegment(newSegment);
}
}
}
else
{
Log.Error("Cannot create surface for " + DecelerationFactor.ToString());
}
}
else
{
Log.Error("Cannot evaluate " + DecelerationFactor.ToString() + " as a function");
}
}
else
{
Log.Error("Cannot create graph for " + SpeedRestrictions.ToString());
}
return(retVal);
}
/// <summary>
/// Creates a graph for the function
/// </summary>
/// <param name="context"></param>
/// <param name="parameter"></param>
/// <param name="explain"></param>
/// <returns></returns>
public override Graph CreateGraph(InterpretationContext context, Parameter parameter, ExplanationPart explain)
{
Graph retVal = new Graph();
StructureValue LocationStruct = context.FindOnStack(Target).Value as StructureValue;
SiDistance location;
SiSpeed speed;
if (LocationStruct != null)
{
IVariable locationField = LocationStruct.Val["Location"] as IVariable;
location = new SiDistance((locationField.Value as DoubleValue).Val);
IVariable speedField = LocationStruct.Val["Speed"] as IVariable;
speed = new SiSpeed((speedField.Value as DoubleValue).Val, SiSpeed_SubUnits.KiloMeter_per_Hour);
Function decelerationFactor = context.FindOnStack(DecelerationFactor).Value as Function;
if (decelerationFactor != null)
{
Surface DecelerationSurface = decelerationFactor.CreateSurface(context, explain);
if (DecelerationSurface != null)
{
AccelerationSpeedDistanceSurface accelerationSurface =
DecelerationSurface.createAccelerationSpeedDistanceSurface(double.MaxValue, double.MaxValue);
QuadraticSpeedDistanceCurve BrakingCurve = null;
try
{
BrakingCurve = EtcsBrakingCurveBuilder.Build_Deceleration_Curve(accelerationSurface, speed,
location);
}
catch (Exception e)
{
retVal.AddSegment(new Graph.Segment(0, double.MaxValue, new Graph.Segment.Curve(0, 0, 0)));
}
SiSpeed finalSpeed = new SiSpeed(GetDoubleValue(context.FindOnStack(EndSpeed).Value),
SiSpeed_SubUnits.KiloMeter_per_Hour);
for (int i = 0; i < BrakingCurve.SegmentCount; i++)
{
QuadraticCurveSegment segment = BrakingCurve[i];
SiSpeed endSpeed = Max(finalSpeed, segment.Get(segment.X.X1));
SiDistance endDistance;
if (endSpeed == finalSpeed)
{
// Ensures that a braking curve is calculated until the finalSpeed
// but not further than the end of the curve segment
SiSpeed tmp = Max(segment.Get(segment.X.X1),
endSpeed - new SiSpeed(0.001));
endDistance = segment.IntersectAt(tmp);
}
else
{
endDistance = segment.X.X1;
}
Graph.Segment newSegment = new Graph.Segment(
segment.X.X0.ToUnits(),
endDistance.ToUnits(),
new Graph.Segment.Curve(
segment.A.ToSubUnits(SiAcceleration_SubUnits.Meter_per_SecondSquare),
segment.V0.ToSubUnits(SiSpeed_SubUnits.KiloMeter_per_Hour),
segment.D0.ToSubUnits(SiDistance_SubUnits.Meter)
)
);
retVal.AddSegment(newSegment);
if (endSpeed == finalSpeed)
{
break;
}
}
}
}
}
return(retVal);
}
