This model simulates cars pulling up to pumps at a gas/petrol station. I have a custom car agent 'MyCar' that passes through an upstream stopline. At this stopline it calls the agent's function which checks the availability of the two pump stations in the roadNetwork in Main. This function returns a RoadNetworkConstant 'PASS_THROUGH_STOP_LINE' or 'STOP_BEFORE_STOP_LINE'.
I'm unable to pass this constant value back into the 'Stop line behavior' property in a CarMoveTo block (for a different stop line further downstream but before the car reaches the pumps) in Main even when I start typing the name of my agent 'MyCar'.
Is it possible to change the Stop Line Behavior dynamically? If so, is this a resonable approach? If not, what would you suggest?
You need to use 'car', not 'MyCar'. Check out the magic light bulb and how keywords work for you: https://www.google.com/url?q=https://www.benjamin-schumann.com/blog/2016/2/4/the-magic-lightbulb-and-how-it-can-help-your-anylogic-modelling&sa=U&ved=2ahUKEwiuz-ytq9D8AhWsSvEDHZccDTUQFnoECAkQAg&usg=AOvVaw3XapUwKyi_Bi9_2JjGrN0b
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In my model I am transporting (path guided) several types of products (motors) by an agv trough a manufacturing line with 27 cycles. It´s a flowing manufacturing line. That means the product gets manufactured while the agv is constantly running.
To model that I created an agent population called "motors" with parameter "axelType" (string) which is loaded from column "axel_type" in database "manufacturing_sequence" (local excelsheet) and is placed on Main.
Each motor is placed on an transporter "agvAssembly" (in Flowchart as: Transporter) and runs from node "locationCycle1" all the way to "locationCycle27".
Now I want to change the transporters speed at each of the 27 cycle nodes dependent on the currently loaded motor. To do that I got another database called "speeds_axel" which includes all the needed speeds for the cycles and respective parameter name for axelType (column axel_type).
So now, when the transporter enters a node I have to check first the nodes name. Than I want to read out the parameter "axelType" of the currently in that node entered agent "Motor" and search in the database for the respective speed.
In the block "transporter Fleet" - "On enter node:" I wrote as an example for cycle 1 the following:
if (node == locationCycle1) {
unit.setMaximumSpeed(
selectFrom(speeds_axel)
.where(speeds_axel.axel_type.eq(motor.axelType))
.firstResult(false, speeds_axel.cycle1)/60.0,MPS);
}
When running the model I get the following error:
"motor cannot be resolved to a variable"
(location: TransporterFleet)
I think that error accures because my approach doesn't specify which motor I mean. How can I clarify to AnyLogic that I always mean the current motor which enters the node?
I need something like this:
if (node == locationCycle1) {
unit.setMaximumSpeed(
selectFrom(speeds_axel)
.where(speeds_axel.axel_type.eq("get motor which is currently in locationCycle1".axelType))
.firstResult(false, speeds_axel.cycle1)/60.0,MPS);
}
the biggest problem in your model is that you don't follow conventions. An agent type should be named with an uppercase first letter
Why is this important? Because you want to make the difference between Motor, motor, and motors
Motor is the class (or Agent Type)
motor is an instance of that class (or agent type)
motors is a population.
Since you don't follow this convention, you make mistakes of this kind since motor is a class
in your case when you do motor.cycle1
if you followed the conventions, you would be doing
Motor.cycle1 (which is obvioulsy wrong)
Note that Motor is the Agent Type name, and what you really want is to know for a particular motor what the value of cycle1 is
The first thing you need to do with this model, is get back to using the conventions, and this will probably solve this problem and many problems in the future.
Just because you have a population called motors (which the agents within your flow 'come from' --- though it looks like they don't actually; see later), this does not mean that you can 'magically' refer to the current agent via the singular form motor at any point in the code. (And, similarly, your agent type being Motor does not mean you can use the lower-case form to refer to 'the current one'.)
In Transporter Fleet block "On enter node" actions, you refer to the current transporter via the unit keyword; see the help page. The motor is not the transporter; it's the thing being transported.
So, just use the "On exit" (or, better, "On at exit") actions of your MoveByTransporter blocks (which trigger on arrival at the destination node), where you can refer to the current motor (the agent in the flow) via the agent keyword; again, see the block help.
But, from a quick glance, there appear to be a few important changes/simplifications you should also make (though hard to definitively tell without details of all your code):
You are using a Source block to add agents (motors) to the flow when you have already created the motors in your population. You should be using an Enter block instead to add the (already-existing) Motor agents to the flow at the appropriate time (triggered by code: I imagine you want one to start at model start time, requiring code in Main's "On startup" action, and then others added either at certain simulation times or when earlier motors reach a certain stage in the process...). If your population was actually just for 'templates' of data for each motor axle type (and you would then potentially create multiple instances of motors for a given axle type) then your current logic might make sense, but your screenshot of your manufacturing_sequence table makes clear that isn't the case. (If you did go that route, you would want to rename your population so that its purpose was clear.)
It looks like you have a 'looping' process (with the same process behaviour for all your in-sequence nodes), so you should look to make your process generic with an explicit loop (so you don't have near-copies of blocks for every node in your sequence). There is a fair amount of detail in terms of how you do this but roughly:
Track the node the motor is currently in (or its sequence number) via a variable in the Motor agent.
Use a collection (List) which contains the nodes-in-order to determine where it has to go to next.
Your process would have a MoveByTransporter --> Delay --> SelectOutput sequence (plus TimeMeasureStart/End if you're using them), where SelectOutput loops back to the MoveByTransporter if the motor is not yet at the last node.
I have a single-lane road expanding into a multi-lane road with a stop line at the end of it. As the car moves from the single-lane section to the multi-lane section it selects the lane seemingly randomly. However, this causes the multi-lane section to back up much quicker than what would happen in real life as one lane will fill up while the other is still empty.
Is there a way to control this behaviour?
I use the following approach in this type of situations:
define a function called fnSelectLane(car)
manually assign the lane by conditions
You can also check how many cars are in each lane with this function int nCarsOnLane(boolean isOnForwardSide, int laneIndex).
Long story short, you can manually assign the lanes, if you don't like the default setup.
Anylogic: This should be simple but I just cannot find it in the help files..
On creating a new agent instance, we know there are four parameters and what they are, but not in what order they were defined. Lets say parameters are "type_of_car" (String), "number_of_pax" (Integer), "automatic" (boolean), "fuel_capacity" (double). Now when calling: new myagenttype("ford", 5, false, 55) the agent gets created as a ford with 55 pax, manual and 5 liter fuel capacity - which is all wrong. (it seems the definition order of the parameters in the agent definition are in a different order)
How do we include the parameter name (or definition) when we call new agenttype() to avoid this problem, ensuring the right value gets assigned to the right parameter?
The problem originates because of a bug in Anylogic's logic in triggering functions. We have a Split which creates a new agent and assigns the agent properties on the "On exit copy" - event, however what Anylogic does is it creates the agent, forward it to the next logical block (a decision node), then execute the code of the decision - all wrong now for the agent's properties are undefined - and only then executes the "On exit copy" event which assigns the agent's properties. Very frustrating.
This is actually not a bug, this is defined in the simulation experiment properties, in the randomness section, with the "selection mode for simultaneous events" property. The default is LIFO, but if you want the opposite behavior in your case you should use FIFO... I always use LIFO too, and in these cases, sometimes I might use a 1milisecond auxiliary delay between the split and the next block in order to control the order manually... if you do that, you will solver your problem in fact... just use a 0.001 miliseconds delay after your split
Now from your Agent Type problem, the arguments for your class constructor should be written in order, and the only way to know the correct order is by using the autocomplete feature when you write new agenttype()... the autocomplete will tell you the order in which you should write your constructor arguments.
I have an airlock (small room called AL_2216) between 2 areas. The airlock has many different agent types passing through it (cart, product, operator, etc). There are queuing areas on either side of the airlock.
Because the space is small, I built a short flowchart that has a queue and restricted area blocks that all agents must pass through when going through this space. If the restricted area's capacity is full, the agents wait in either the InsideQueueArea or OutsideQueueArea depending on the direction they're going.
I send agents via Exit and Enter blocks to this flowchart and it works great on the top portion of the flowchart.
BUT if I try to use an Enter or Exit block in the prepare flowchart, I get this error:
I tried using a custom block instead of Enter and Exit blocks, but that creates a new instance of the code each time and the restrictions don't work together across the multiple custom blocks.
This airlock is just one of many in my model. Without referring to the same code, I'll have multiple copies that need to refer to each other's restricted areas and the flowcharts become huge and complicated. Is there a way to get around this?
EDIT:
I'm not sure what to do with these ports. They have no properties that do anything:
EDIT2:
Here's a file to see the behavior - Model2.zip
The Prepared flowchart portion is set to "ignore" so the code will run. You can see the operators and the carts passing through AL_2216 with only 2 being allowed at a time. If you uncheck "ignore" for the prepare flowchart, the error will trigger.
AnyLogic sent the right answer!!
So I was asking Anylogic a different question and they recognized my name from this post! They sent a fix to me and it works exactly the way it should! The exception error message I was getting "out: 0 isn't supported for..." made me think the exit/enter blocks were not supported in perparation flowcharts.
But actually, the seizeCart block didn't know where to start the prep flowchart because it wasn't directly connected to the resource task start block. A quick setting change under the Advanced section of the seizeCart block defining which resource task start block to start at did the trick! Here's the email from AnyLogic:
-The error text and documentation are not sufficient for understanding this (the error text is confusing), I suppose it is obsolete error text. We will rectify the description;
-Under the question there is a more generic discussion which seems to be unrelated to the initial problem. Please let me know if I miss something or if your model does not work as you expect even after adjustment of seizeCart block property.
I think you should replace the Enter and Exit blocks that lead to the bottom input of your seizeCart Seize block with simple Port objects (from the Agent palette).
As per the help for Seize:
So it wants a direct link to a ResourceTaskStart flow and your Enter/Exit combinations might be ... not "direct" enough... Try it.
So here's what I ended up doing. It's the best I could come up with that could be easily replicated for lots of airlocks.
I've added a wait block (dummyThruAL_2216) to my Product flowchart prior to seizing the cart. This wait block injects a new Agent into sourceDummy at the cartHome node. The dummy then seizes a cart and moves through the airlock and it's restriction. Upon exiting the restriction, I check what type of agent and direct the agent to the correct exit block. The dummy agent and cart move to the Product where the dummy agent releases the cart and sinks. The sink frees the wait block and the Product seizes the cart that is right next to it and continues on it's journey.
It's an easy copy/paste to add more airlocks. Not as nice as my original, but what are you going to do... Thanks for everyone's help and suggestions.
As others have said, there are (not really documented) restrictions on what blocks you can use in preparation and wrap-up flowcharts, which mean what you're attempting won't work.
As you say, it's important to keep a single 'instance' of the airlock flow so that the restrictions (queue and restricted area) are 'global' when this represents the same physical airlock. (Otherwise a repeated custom block is precisely what you should use for each different physical airlock.)
Your best option (and assuming you needed to attach the Cart resource to the Product) is probably to
Add dummy agents (via Source block inject calls) to a separate mini-process that represents your resource preparation requirement (but now not attached to the Seize block).
Replace the Seize in your main process with a Seize-Wait-Release-Seize combination:
The Seize block seizes the cart as normal (without moving or attaching it; no 'Send seized resources' or 'Attach seized resources' options) and then injects an agent into your mini-process (which can use Exit and Enter blocks to use the airlock sub-process). This agent represents the seized resource agent (Cart) and thus should start where it starts and be animated so it looks like it. (You can make the actual Cart temporarily non-visible during this mini-process.)
When the agent reaches the end of the mini-process (at a Sink block), instantly move the related Cart to your node (use jumpTo), make it visible again and free the Product agent from the Wait block
Release the seized Cart and then immediately re-Seize it, but now attaching it (so the animation looks correct). If you use the Resource selection 'Nearest to the agent' option you should be guaranteed to seize the correct cart. (You can also use the 'Customise resource choice' option with some code to ensure that you absolutely always choose the same Cart.)
(It is simpler than the above if you don't care about having a correct animation, and you can use custom blocks to make this block combination reusable and thus not too clunky.)
Edit: A very similar alternative which also works (and is the basis for your own answer) is to have a dummy agent representing your Product in the sub-flow which seizes (and attaches) the actual Cart agent, leaving it at the Product's location to be immediately seized as above. This is slightly better since you don't have to worry about the visibility and 'jumping' of the real resource agent, plus you can move a Seize and a Release from the main flow (which now just has Wait-Seize) to the sub-flow (thus 'hiding them away').
I want to implement a connected autonomous vehicle fleet in AnyLogic. Because of this, a vehicle agent has the ability to change its route. My understanding is that using the standard "MoveTo" block lets you move the vehicle agent only once by telling it what road to move the agent to.
For example:
Any vehicle following the above block can be created on any road that is specified in road4Source, then move to another road specified in moveToRoad2 block and then will be destroyed/deleted/discarded when it reaches the endOfRoute block.
However, since the vehicle can choose the route for itself, I only know the Origin and the Destination of the vehicle and not sure what route it will take. So, the number of MoveTo blocks should ideally be dynamic.
Considering this, is it possible to reuse MoveTo blocks (consider it a kind of a while loop) so that that the vehicle remains in the MoveTo block until it reaches the Destination (a particular road in my case)?
Something like this:
So that in the Road argument of moveToRoad2, I can put something like(could be wrong just for illustration):
car.getRoad() == car.destination ? endOfRoute : car.getRoad()
where car.getRoad() would return the road that the vehicle wants to go to and if it is equal to the destination of the car then it would go the endOfRoute block.
EDIT 1
I understand now that if there are two connections to the same port, AnyLogic will throw an error:
Out port can't be connected with more than one In Port.
So is there any other way to achieve what I want to do here?
First, this is the configuration you want:
Then you need to generate a collection of roads that the car will take... This collection is generated in the carSource... or you can update it as you progress in the "loop".
the car agent must have a variable that will start with 0 and will increment +1 every time it exits carMoveTo...
So the new road that the car will take is:
collection.get(car.variable)
And on exit of carMoveTo:
car.variable++;
In the selectOutput the condition for true would be:
agent.variable==collection.size()
I hope this helps...
Nevertheless, if you have too much traffic, you will see big problems in your model because the car doesn't necessarily recognize traffic after the destination in the carMoveTo so you may have crushes... or maybe not... depends on different factors.