Tow Tractor + Trailers

Hi

I am currently working on a material handling simulation. I need to simulate transporters of varying lengths. Currently I am changing the length of the fork-truck object when it loads a flow item. This works fine but the graphics look poor.

I am trying to represent tow tractors with varying quantities of trailers. Is there an easy way to do this? The tow tractors are small single man vehicles that can pull between zero and 9 trailers. I appreciate this will probably be difficult to simulate however it would be a great addition to Flexsim if this was a simple option as most manufacturing plants use tow tractors that pull trailers.

Many Thanks

Anth

We recently developed the ability to simulate multi-car train movement along a track as part of a larger rail yard simulation project for one of our clients. We hope to find the time during Q1 of 2008 to wrap the functionality into a package that we can share with our users. It might be an overkill for the tow tractor and trailer scenario you're referring to however. I might have a couple simple suggestions for you, but let me first ask you a few questions:

1) have you chosen to model the vehicles as Flowitems, TaskExecuters or TaskExecuterFlowitems?
2) how important is articulated (individual car) movement?
3) do you have 3D shapes for the tractor and trailers, or are you simply using boxes?

Without giving a lot of detail, here are some different ideas for you:

1) Hierarchically place trailer objects into the tractor object.
2) Use flowitems to represent tractor and trailers traveling along a conveyor.
2) Use separate taskexecuters for tractor and each trailer. Give all taskexecuters making up the train a tasksequence to travel at the same time but to slightly offset destinations.

Cliff

Thanks for the reply Cliff.

I have finshed working on the model for now and we got some satisfactory results.

I'll quickly answer your questions before I explain what I did.

1) I used the Transporter object to represent the transporter and trailer/s.
2) Individual car movement is only important from a graphical point of view.
3) I don't have any 3D shapes for the tracotor and trailers as yet. The tow tractors look like slightly smaller versions of the ones you get at DisneyLand that help transport people everywhere.

I simulated the tractor and trailer using the transporter object. I set a label called 'length' on the flow item the transporter was carrying, as the transporter loaded the flow item I altered the length and colour of the transporter. The varying lengths were to represent different quantities of trailers.

Graphically this doesn't look very good but it performs the task to the required level for this simple model.

I've attached the model in case you want to view it.

Anth