Phase 2. Defining logic

Define the model logic using AnyLogic Rail Library blocks

1. Add the following blocks to the flowchart:  TrainSource,  TrainMoveTo,  TrainDecouple,  TrainCouple,  TrainDispose. We will use them to define the train logic.
2. Start the flowchart with the train generating  TrainSource block, then add  TrainMoveTo block placing it close to the first block so that they connect automatically. Proceed adding other blocks to the flowchart as shown on the figure below.

   

3. Specify parameters for the  TrainSource and  TrainMoveTo blocks.

   We will start with specifying trains to appear at the  stopLineEntry track point every 15 minutes.

   TrainSource:
   Interarrival time: 15 minutes
   # of cars (including loco): 11
   Position on track:  stopLineEntry
   Once generated, every train will head to the  stopLineArrival track point where it will decelerate and stop.
    TrainMoveTo
   Route is: Calculated automatically from current to target track
   Target is: A given position on track
   Position on track:  stopLineArrival
   Finish options: Decelerate and stop
4. We have also added  TrainDecouple block which is used to detach a given number of cars from the incoming train. In the block’s parameters you can see that it decouples one car from the train by default, namely the first car (which is a locomotive in our case). A loco leaves the block through its bottom port outDecoupled.
5.  TrainCouple block will be used to couple a loco with rail cars into a train.

Below you can find the description of the Rail Library blocks that we are using.

Modify the flowchart

Add more  TrainMoveTo blocks and connect them as shown on the picture by following the steps below to specify train’s behavior on the rail yard which will include loco decoupling and going back using the lead track for coupling with the rail cars again and moving them to the hump.

Start with connecting  TrainMoveTo block to the outDecoupled port (the one at the bottom) of the  TrainDecouple block as we will define the logic for the detached locomotive only.

1. Add one more  TrainMoveTo block into the flowchart (trainMoveTo1). Define parameters of the new block to move the locomotive to  stopLineHump and stop it there.
   Route is: Calculated automatically from current to target track
   Target is: A given position on track
   Position on track:  stopLineHump
   Finish options: Decelerate and stop
2. Add two more  TrainMoveTo blocks (trainMoveTo2, trainMoveTo3) by Ctrl + dragging (macOS: Cmd + dragging) the one you just edited.
3. Modify parameters of the trainMoveTo2 block. At this point the locomotive is on its own and we need it to push the rail cars to the hump, i.e. it should get back to the  stopLineEntry and then couple with the train end. The locomotive will move backwards omitting the  trackArrival track that the rail cars are on:
   Direction: Backward
   Route should not contain:  trackArrival
   Position on track:  stopLineEntry
4. Pay attention to the number of connections leading from the trainMoveTo3 block to  TrainCouple block. The bottom port in the  TrainMoveTo block, as compared to the out port on the right, is used for a train that hits another train. In our case the collision corresponds to coupling of the locomotive arriving to the  stopLineArrival track position with the rail cars which we have previously detached from this loco.
5. Now modify parameters of the trainMoveTo3 block to move the loco from its current position to the  stopLineArrival track position:
   Position on track:  stopLineArrival

   

   Now that we have moved the loco to the back of the train consisting of rail cars, we need to add another  TrainMoveTo block by Ctrl + dragging (macOS: Cmd dragging) trainMoveTo1 block. It will simulate loco pushing rail cars to the hump area, represented in our model by the  stopLineHump element.

6. Modify parameters of the trainMoveTo4: Position on track:  stopLineHump
   Cruise speed (0 for no change): 5 meters per second
7. Add  Delay block from the  Process Modeling Library palette to simulate a time delay and define its parameters:
   Delay time: 15 seconds

We have completed Phase 2. You can run the model to see how trains appear and move along our track.

Run the model

1. Click the  Run toolbar button and choose the experiment you want to run from the drop-down list. Your simulation experiment is called Hump Yard / Simulation.
   On starting the model, you will see the model window. It displays the presentation of the top-level agent type (by default, it’s  Main).
   Observe the process dynamics. If needed, adjust the execution speed to your needs using  slow down and  speed up controls.
   If you see the "The car being created must fully be on one track" error, it means that there is not enough space for the whole train to fit in on the railway track before the  stopLineEntry  element. In this case you will need to increase the length of the  trackEntry railway track and move the  stopLineEntry further from the track’s start point.

   

   The train stops at the stop line and the loco uses the lead track to couple with the train end.

   

You can see that the loco moves the rail cars to the hump and stops for decoupling and classification.

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