Production line with long products

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neutral
Posts: 6
Joined: Thursday 09 June, 2011 - 13:59

Production line with long products

Post by neutral »

Hi,

So I need to model a production line which consists of conveyors that are 4 meters long each. Between these conveyors there are usually some type of servers. The products that go through this production line vary in length from 2 meters to 10 meters. Now my question is, how would model this in a way that prevents the products from colliding each other?
In real life, of course, the products could move with very little space in between them, but so far from what I've managed to figure out, I have 2 options: 1) "reserve" the conveyor for one product, only freeing it after it has completely left the conveyor. The downside of this is that the gap between two products can get very long. 2) form the conveyors from 1 meter long pieces and open and close these as the product moves. This, however, probably gets very very hard to maintain if the length of the conveyors is anything more than 10 meters.

The easiest way to clarify this problem is by having 2 conveyors of 5 meters each, and set the first conveyor to a much higher speed than the second one. Now when you let the source pump up products of say 7 meters, the faster conveyor will "push the second product through the first one". This is obviously not how the line works in real life.

So is there some kind of way to prevent the collision, even when the products are longer than the conveyor (ie. the "end" of the product is still on top of the previous conveyor even when it is moving on top of the next one)?
Jeroen
Posts: 9
Joined: Monday 17 January, 2011 - 10:02

Re: Production line with long products

Post by Jeroen »

Hi,

If you use the advanced conveyors a product overlapping several conveyors is handled automatically.
Each conveyor will allow a next product when the end of the previous product is passed the beginning of this conveyor.
If required it is also possible to set a desired gap between products which can be different each conveyor.
The speed of each conveyor can also be different. The product gets the same speed as the speed of the conveyor on which the front side of the product is.

Internally we keep track of the distance a product still has to travel on a conveyor on the table of the product; so you cannot use this table for other purposes.

Regards,
Jeroen
neutral
Posts: 6
Joined: Thursday 09 June, 2011 - 13:59

Re: Production line with long products

Post by neutral »

Thank you for the reply!

Now I feel a little silly for not finding that myself :) Thanks!

I have one additional question though. Let's say that I have a server that represents a machine that operates on a product while the product in real life is still on the conveyor (maybe the product stops on the conveyor while a robot attaches some extra parts?). How would I model this with ED? If I just have a server representing the robot, the product will leave the advanced conveyor and move into the server, which in turn means that another product will "run it over". So is there a way to have the product "reserve" the space in the conveyor while the server operates on it? The conveyor belt will continue after the said server, so the server is just in the middle of a long production line.
Jeroen
Posts: 9
Joined: Monday 17 January, 2011 - 10:02

Re: Production line with long products

Post by Jeroen »

No problem, luckily not all solutions are hard ;) .

To model working on product which is on a conveyor you can use the sensors of the advanced conveyors. You can position one at any location on the conveyor, where ever you want to stop the product. You then have to activate a trigger and write code on that. Some tips for the code, you can:
  • Use the ED variable s to refer to the product.
  • Use the ED variable c to refer the conveyor on which the product is.
  • Use the function Conveyors_StopConveyor(c, 1) to stop the conveyor the conveyor. The second parameter ensures that the conveyor can only be restarted again manually (e.g. be creating an event).
  • Create an event with eventcode CONVEYORS_START_CONVEYOR_EVENT after x seconds to start the conveyor again. You don't need to pass an involved atom (5th paramater of CreateEvent).
Regards,
Jeroen
neutral
Posts: 6
Joined: Thursday 09 June, 2011 - 13:59

Re: Production line with long products

Post by neutral »

Ok so the advanced conveyor was actually the solution to all the problems. I think the features of the conveyor could be slightly better documented though :)
Thanks for the tips!
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