/// <summary>
/// Method to compute new speed and new position for the current platoon based on
/// speed limit restrictions and maintaining minimum required distance with predecessor.
/// </summary>
/// <param name="prev">Reference to previous platoon</param>
/// <param name="newPosn">New tentative position to move to</param>
/// <param name="newSpeed">New speed to move to newPosn</param>
private void computeNewSpeedAndPosition(Platoon prev, out int newPosn, out int newSpeed)
{
int distToTravel = 0; // Distance to travel through in one time slot
/**
* If there's no platoon ahead of this platoon then in one time unit, a platoon
* can move as much as the speedLimit.
*/
if(prev == null)
{
distToTravel = speedLimit;
}
else
{
/**
* If there is a platoon ahead of this platoon, compute distToTravel
* such that it maintains "interPlatoonDist" with it.
*/
if(this.dirn == Direction.NS || this.dirn == Direction.EW)
{
distToTravel = prev.rearPosition() - currPosn;
}
if(this.dirn == Direction.SN || this.dirn == Direction.WE)
{
distToTravel = currPosn - prev.rearPosition();
}
distToTravel = distToTravel - interPlatoonDist;
/**
* However, speedLimit can't be exceeded. So if distToTravel > speedLimit, then
* reduce distToTravel to speedLimit.
*/
if(distToTravel > speedLimit)
distToTravel = speedLimit;
}
/**
* Compute newSpeed and newPosn.
*/
newSpeed = distToTravel;
if(this.dirn == Direction.NS || this.dirn == Direction.EW)
{
newPosn = currPosn + newSpeed;
}
else
if(this.dirn == Direction.SN || this.dirn == Direction.WE)
{
newPosn = currPosn - newSpeed;
}
else
{
/**
* Written ONLY to satisfy the compiler
*/
newPosn = -100000;
newSpeed = -100000;
}
}
/// <summary>
/// Algorithm used by the platoons to move
/// </summary>
/// <param name="prev">Previous platoon's reference</param>
/// <param name="currTime">Current time</param>
/// <returns></returns>
public void move(Platoon prev, int currTime)
{
int newSpeed = -1; // New speed
int newPosn = -1; // New position
bool canMerge = true; // Can merge with previous platoon
int nextXPosn; // Position of next intersection
bool moveSucceeded; // Move to new position succeeded
int nextIntxnNum = -2000; // Number of next intersection - NOT USED RIGHT NOW
/**
* Compute new speed and new position for the platoon
*/
computeNewSpeedAndPosition(prev, out newPosn, out newSpeed);
/**
* If newSpeed was zero, that means that the platoon cannot move due to predecessor platoon
* blocking it's path in this iteration, so return without moving.
*/
if(newSpeed == 0)
{
return;
}
moveSucceeded = checkIfMoveAllowed(currTime, newPosn, newSpeed, out nextXPosn);
if(moveSucceeded == true)
{
currPosn = newPosn;
currSpeed = newSpeed;
}
else
{
currPosn = nextXPosn;
currSpeed = 0;
}
}
/// <summary>
/// Helper method used by createPlatoon to create platoons.
/// </summary>
/// <param name="currTime">Current time</param>
/// <param name="laneID">Lane ID for which platoon must be created 0 - downLane, 1 - upLane</param>
private void createPlatoonHelper(int currTime, int laneID)
{
Platoon p; // Temp object Platoon
int posn; // Rear position of last platoon on that lane
int numVeh; // Number of vehicles to add in platoon
int startPt; // Starting position for platoon
Vehicle []v; // Array of vehicles to add to platoon
int platoonDirn;// Platoon's direction
Queue waitQ; // Waiting queue
ArrayList lane; // Lane
/**
* Select values corresponding to either downlane or uplane
*/
if(laneID == 0)
{
lane = downLane;
waitQ = downQueue;
startPt = this.startPos;
// For downlane, direction is either NS or EW
if(orient == RoadOrientation.NS)
platoonDirn = Direction.NS;
else
platoonDirn = Direction.EW;
}
else
{
lane = upLane;
waitQ = upQueue;
startPt = this.endPos;
// For upLane, direction is either SN or WE
if(orient == RoadOrientation.NS)
platoonDirn = Direction.SN;
else
platoonDirn = Direction.WE;
}
/**
* If this is the time to create a platoon and some vehicles are waiting to join a platoon
* then only create a platoon.
*/
if((currTime % period == 0) && (waitQ.Count > 0))
{
/**
* Get the position of the last platoon on that lane.
*/
if(lane.Count > 0)
{
p = (Platoon) lane[lane.Count - 1];
posn = p.rearPosition();
/**
* If there isn't place to create a new platoon such that minimum inter platoon distance
* is maintained with last platoon on that lane, don't attempt to create a platoon and return.
*/
if(laneID == 0)
{
if(posn < this.startPos + ip.interPlatoonDist)
{
/**
* Increment platoon not created counter.
*/
roadCntr.incrementPlatoonNotCreatedCount();
return;
}
}
else
{
if(this.endPos - posn < ip.interPlatoonDist)
{
/**
* Increment platoon not created counter.
*/
roadCntr.incrementPlatoonNotCreatedCount();
return;
}
}
}
// Get how many vehicles to add to this platoon
numVeh = Math.Min(numVehiclesInPlatoon, waitQ.Count);
v = new Vehicle[numVeh];
// Remove those many vehicles from the waiting queue
for(int i = 0; i < numVeh; i++)
{
v[i] = (Vehicle) waitQ.Dequeue();
// Set vehicles start journey time - this determines vehicle's wait time
v[i].setStartJourneyTime(currTime);
}
p = new Platoon(v, numVehiclesInPlatoon, platoonDirn, travelSpeed, startPt, this);
if(laneID == 1)
{
// Console.WriteLine("Platoon created at posn {0} Dirn {1} on Road {2} Orient {3}", startPt, platoonDirn, this.roadNum, this.orient);
}
lane.Add(p);
/**
* Update platoon arrival counter in road perf counter
*/
roadCntr.platoonCreated();
}
}
/// <summary>
/// This method is invoked by the platoon to merge with its predecessor platoon. The merging platoon
/// first obtains the capacity of the succeeding platoon and then merges all possible vehicles to its
/// predecessor. If this platoon merges all its vehicles to predecessor, then it gets itself removed from the road
/// ONLY COMPLETE MERGE IS ALLOWED.
/// A succeeding platoon can invoke this method when it is intra-platoon dist away from its predecessor. Distance check
/// is not done in this method.
/// </summary>
/// <param name="pred">Instance of preceding platoon</param>
/// <returns>A boolean value true if merge is possible, false otherwise</returns>
public bool mergeWithPredecessor(Platoon pred)
{
int predCapacity; // Additional capacity of predecessor platoon
/**
* Query the preceding platoon for additional platoons that it can accept.
* If it's not possible to merge more platoons then return false.
*/
predCapacity = pred.mergeCapacity();
/**
* ONLY COMPLETE MERGES ARE ALLOWED. Thus, if the number of vehicles in current platoon
* are greater than the capacity of preceding platoon, do not attempt to merge and return
* false.
*/
if(vehicles.Count > predCapacity)
return false;
// Add the removed vehicles into the preceding platoon
pred.acceptSuccessor(vehicles);
/**
* This loop removes all the vehicles from the vehicles array of this platoon
*/
vehicles.RemoveRange(0, vehicles.Count);
// while(vehicles.Count > 0)
// {
// vehicles.RemoveAt(0);
// }
// Update self length
platoonLen = 0;
// Set currposn to some invalid value
currPosn = -1000000;
return true;
}
/// <summary>
/// Computes the statistics for all the platoons in the system
/// </summary>
/// <param name="currTime">Current Time</param>
public void getRoadPlatoonStatistics(int currTime)
{
Platoon p;
/**
* Add the counters for all the platoons in transit.
*/
for(int i = 0; i < downLane.Count; i++)
{
p = (Platoon) downLane[i];
roadCntr.addPlatoonCounter(p.getCounters(currTime));
}
for(int i = 0; i < upLane.Count; i++)
{
p = (Platoon) upLane[i];
roadCntr.addPlatoonCounter(p.getCounters(currTime));
}
/**
* Create a new platoon containing all the vehicles in the holding queue and then
* add that to the roadCntr so that transit time of these vehicles get counted also.
*/
Vehicle []v = new Vehicle[downQueue.Count];
int cnt = downQueue.Count;
for(int i = 0; i < cnt; i++)
{
v[i] = (Vehicle) downQueue.Dequeue();
}
p = new Platoon(v, v.Length, Direction.NS, ip.speedLimit, 0, this);
roadCntr.addPlatoonCounter(p.getCounters(currTime));
/**
* Do the same for up queue
*/
v = new Vehicle[upQueue.Count];
cnt = upQueue.Count;
for(int i = 0; i < cnt; i++)
{
v[i] = (Vehicle) upQueue.Dequeue();
}
p = new Platoon(v, v.Length, Direction.SN, ip.speedLimit, 0, this);
roadCntr.addPlatoonCounter(p.getCounters(currTime));
}