private static void CreateTrackingInfo(Trolley trolley)
{
var newTrackingInfo = new TrolleyTrackingInfo(trolley);
if (activeRoutes.Count == 1)
{
// For a single active route, all trolleys follow that route
newTrackingInfo.CurrentRoute = activeRoutes.First().Value;
}
trolleyTrackingInfo.Add(trolley.ID, newTrackingInfo);
}
private static void UpdateStopTime(TrolleyTrackingInfo trackingInfo)
{
// See if trolley has moved far enough to justify a full stop distance check
var currentLocation = new Coordinate((double)trackingInfo.CurrentTrolley.CurrentLat, (double)trackingInfo.CurrentTrolley.CurrentLon);
if (currentLocation.Distance(trackingInfo.LastReportedLocation) > MinMoveDistance)
{
// Heading will be integer 0..359
trackingInfo.CurrentHeading = ((int)(trackingInfo.LastReportedLocation.DirectionToward(currentLocation) + 0.5)) % 360;
CheckForStopInRange(trackingInfo, currentLocation);
trackingInfo.LastReportedLocation = currentLocation;
}
}
/// <summary>
/// Find stop index in the ordered stop list
/// </summary>
/// <param name="trackingInfo"></param>
/// <param name="stopID"></param>
/// <returns>Stop index or -1 if not found</returns>
private static int FindRouteStopIndex(TrolleyTrackingInfo trackingInfo, int stopID)
{
var stopIndex = -1;
for (int i = 0; i < trackingInfo.CurrentRoute.RouteStops.Count; i++)
{
if (trackingInfo.CurrentRoute.RouteStops[i].StopID == stopID)
{
stopIndex = i;
break;
}
}
return(stopIndex);
}
/// <summary>
/// Test that route path next to this stop is heading in the same direction as trolley,
/// and not the return path
/// </summary>
/// <param name="trackingInfo">Tracking info - CurrentRouteStop and PreviousRouteStop will be assigned here</param>
/// <param name="currentLocation"></param>
/// <param name="stopSummary"></param>
/// <returns></returns>
private static bool StopIsOnRight(TrolleyTrackingInfo trackingInfo, Coordinate currentLocation, StopSummary stopSummary)
{
// Find route direction at our current location (stop)
var routeStopIndex = FindRouteStopIndex(trackingInfo, stopSummary.ID);
if (routeStopIndex < 0)
{
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Route Stop Index not found");
return(false);
}
var routeStop = trackingInfo.CurrentRoute.RouteStops[routeStopIndex];
var numStops = trackingInfo.CurrentRoute.RouteStops.Count;
trackingInfo.PreviousRouteStop = trackingInfo.CurrentRoute.RouteStops[(routeStopIndex + numStops - 1) % numStops];
trackingInfo.CurrentRouteStop = routeStop;
trackingInfo.CurrentRouteStopIndex = routeStopIndex;
var routeSegmentIndex = routeStop.RouteSegmentIndex;
if (routeSegmentIndex < 0)
{
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Route Stop Index not set");
return(false);
}
var segmentCount = trackingInfo.CurrentRoute.Shapes.Count;
var segmentEnd = trackingInfo.CurrentRoute.Shapes[routeSegmentIndex];
var segmentStart = trackingInfo.CurrentRoute.Shapes[(routeSegmentIndex + segmentCount - 1) % segmentCount];
var routeSegmentStart = new Coordinate(segmentStart.Lat, segmentStart.Lon);
var routeSegmentEnd = new Coordinate(segmentEnd.Lat, segmentEnd.Lon);
var routeDirection = routeSegmentStart.DirectionToward(routeSegmentEnd);
var trolleyDirection = trackingInfo.CurrentHeading;
// Convert directions from 0..360 to +/-180 for comparison
if (routeDirection > 180)
{
routeDirection = routeDirection - 360;
}
if (trolleyDirection > 180)
{
trolleyDirection = trolleyDirection - 360;
}
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Route direction: {routeDirection}, trolley heading: {trolleyDirection}");
if (Math.Abs((int)routeDirection - trolleyDirection) < 130)
{
return(true);
}
return(false);
}
/// <summary>
/// Calculate and update travel time from previous to current stop
/// </summary>
/// <param name="trackingInfo"></param>
private static void UpdateTravelTime(TrolleyTrackingInfo trackingInfo)
{
var routeStop = trackingInfo.CurrentRouteStop;
if (routeStop == null)
{
return;
}
var lastRouteStop = trackingInfo.PreviousRouteStop;
if (!lastRouteStop.LastTimeAtStop.HasValue)
{
return;
}
var elapsedSeconds = (routeStop.LastTimeAtStop - lastRouteStop.LastTimeAtStop).Value.TotalSeconds;
if (elapsedSeconds > MaxTimeBetweenStops)
{
// Invalid time - likely from a long break or first stop of the day
return;
}
var newTravelTime = (int)elapsedSeconds;
if (routeStop.AverageTravelTimeToNextStop != 0)
{
// Average is approximted by a weighted moving average instead of true moving average
int percentWeight = 50;
var adjustment = (newTravelTime - routeStop.AverageTravelTimeToNextStop) * percentWeight / 100;
// Avoid having a single anomaly create a large swing
if (Math.Abs(adjustment) > (routeStop.AverageTravelTimeToNextStop / 2))
{
adjustment = (routeStop.AverageTravelTimeToNextStop / 2) * Math.Sign(adjustment);
}
newTravelTime = routeStop.AverageTravelTimeToNextStop + adjustment;
if (newTravelTime < MinTimeBetweenStops)
{
newTravelTime = MinTimeBetweenStops;
}
}
routeStop.AverageTravelTimeToNextStop = newTravelTime;
UpdateTravelTimeInDB(routeStop);
}
/// <summary>
/// Check for stop proximity - try to minimize number of polled stops
/// - First preference is the previous stop
/// Then loop through all stops
/// </summary>
/// <param name="trackingInfo"></param>
/// <param name="currentLocation"></param>
private static void CheckForStopInRange(TrolleyTrackingInfo trackingInfo, Coordinate currentLocation)
{
if (stopSummaries.ContainsKey(trackingInfo.LastStopID))
{
// Test if Still within stop zone
var stopSummary = stopSummaries[trackingInfo.LastStopID];
if (currentLocation.Distance(new Coordinate(stopSummary.Lat, stopSummary.Lon)) < StopRadiusCheck)
{
return;
}
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Left stop zone {stopSummary.Name}");
}
if (trackingInfo.CurrentRoute == null)
{
return; // No route found to assign to trolley
}
foreach (var routeStop in trackingInfo.CurrentRoute.RouteStops)
{
var stopID = routeStop.StopID;
var stopSummary = stopSummaries[stopID];
if (currentLocation.Distance(new Coordinate(stopSummary.Lat, stopSummary.Lon)) < StopRadiusCheck)
{
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Entered stop zone {stopSummary.Name}");
// Found new stop zone; validate that it's an upcoming stop on right side and not on the left side
// (which would be on the return trip)
if (StopIsOnRight(trackingInfo, currentLocation, stopSummary))
{
UpdateStopArrivalTime(trackingInfo.CurrentRouteStop);
UpdateTravelTime(trackingInfo);
PredictStopArrivalTimes(trackingInfo);
trackingInfo.LastStopID = stopSummary.ID;
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Stop was on right {stopSummary.Name}");
return;
}
else
{
Debug.WriteLine($"Trolley {trackingInfo.CurrentTrolley.Number} Stop not on right {stopSummary.Name}");
}
}
}
// Not currently in any stop zone
trackingInfo.LastStopID = -1;
}
/// <summary>
/// Set or refresh stop arrival times for all stops on this route based on just arriving at current stop
/// </summary>
/// <param name="trackingInfo"></param>
/// <param name="currentLocation"></param>
/// <param name="stopSummary"></param>
private static void PredictStopArrivalTimes(TrolleyTrackingInfo trackingInfo)
{
var trolleyNumber = trackingInfo.CurrentTrolley.Number;
var now = UTCToLocalTime.LocalTimeFromUTC(DateTime.UtcNow);
var stopsCount = trackingInfo.CurrentRoute.RouteStops.Count;
int travelSeconds = 0; // Total travel time from current stop
for (var i = 0; i <= stopsCount; i++)
{
var stopIndex = (trackingInfo.CurrentRouteStopIndex + i) % stopsCount;
var routeStop = trackingInfo.CurrentRoute.RouteStops[stopIndex];
if (routeStop.LastTimeAtStop.HasValue)
{
var timeAtStop = now.AddSeconds(travelSeconds);
var previousRouteStop = trackingInfo.CurrentRoute.RouteStops[(stopIndex + stopsCount - 1) % stopsCount];
var previousSummary = stopSummaries[previousRouteStop.StopID];
SetArrivalTime(trolleyNumber, previousSummary, timeAtStop);
travelSeconds += routeStop.AverageTravelTimeToNextStop;
}
}
}