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Old 08-27-2008
Nathan Dwyer Nathan Dwyer is offline
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Default Isolating Operator from overhead cranes

I am trying to model a couple of overhead cranes on a shared runway that are placing products on trucks.

They should not collide, and collision detection has not proven very robust for my application as setting the priority of the task or giving priority to an individual crane results in the lower priority crane respecting the higher priority crane and moving out of the way as I require, but the higher priority crane will ignore the lower priority crane if it is part way though executing an unload operation.

I also need to include an operator approaching the truck and roping down the load after each layer is packed. During this time neither crane may approach the truck (represented as a combiner) or try and pass over the top of the truck to get to the second truck "across the driveway", but should instead continue on with other tasks, like putting arriving product away to the rack.

At first I tried to set up collision detection between the operator and the crane but I could not get collision detection between them to work, and I think this may be becuase the operator doesn't have a task assisgned, nor a priority since he is not actually doing anything other than causing a delay.

I have tried to adapt Tom David's concept from Sample_3CraneControlTD4 of closing the path with Network Nodes, but my poor understanding of Flexscript has meant I have not been able to adapt it to work properly (as evidenced in the attached example.

Any help is greatly appreciated.


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Old 08-27-2008
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Tom David Tom David is offline
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Because I am very busy in the moment and did not know when I will find the time to have a look into your model, I will just give you the general idea how I did the section control in my sample model.

Important is that the cranes and operator use one network system. If one taskexecuter (crane or operator) goes in the special section, close the NetworkNodes for the others (closenodeedge()). So you might need some additional NetworkNodes like I used in my sample model. It is important to find out which is the right nodeedge() (e.g. by a message or print out in the Output Console). If the taskexecuter leaves the special section he opens the NetworkNodes for the others again. You might need one NetworkNode for the control and an additional one for the closing/opening.

I hope this will give you a point to start. Maybe you can have a deeper look into my sample model to get a better understanding on how I did it there.

Or maybe someone else has the time and give you some further hints or can help you with your model.

Good success!
tom the (A)tom: "We have solved our problems ... now we have to fight the solutions."

Thread Thread Starter Forum Replies Last Post
Can’t stop cranes colliding Kenny Macleod Q&A 8 07-16-2008 10:18 AM

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