ATTENTION

This FlexSim Community Forum is read-only. Please post any new questions, ideas, or discussions to our new community (we call it Answers) at https://answers.flexsim.com/. Our new Question & Answer site brings a modern, mobile-friendly interface and more focus on getting answers quickly. There are a few differences between how our new Q&A community works vs. a classic, threaded-conversation-style forum like the one below, so be sure to read our Answers Best Practices.


flexsim.com

Go Back   FlexSim Community Forum > FlexSim Software > Q&A
Downloads

Q&A Using Flexsim and building models

  #1  
Old 02-12-2015
syseo's Avatar
syseo syseo is offline
Flexsim User
 
Join Date: Aug 2007
Location: Korea
Posts: 290
Downloads: 439
Uploads: 0
Thanks: 249
Thanked 63 Times in 41 Posts
Rep Power: 211
syseo has a spectacular aura aboutsyseo has a spectacular aura about
Default What's the difference of using ACC / DEC and not using them...?

I want to know the differences about when using Acceleration / Deceleration and Not using them.

I attached the example model file.

Their moving animations are same.
I want to know when using them and what will be different after setting acc / dec?
Attached Files
File Type: fsm AccDec.fsm (22.0 KB, 431 views)
  #2  
Old 02-12-2015
Jörg Vogel's Avatar
Jörg Vogel Jörg Vogel is offline
Flexsim User
 
Join Date: Sep 2007
Location: Hannover, Germany
Posts: 643
Downloads: 35
Uploads: 0
Thanks: 802
Thanked 665 Times in 410 Posts
Rep Power: 642
Jörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond repute
Default

Hello syseo,

you can change the traveling speed with a photo eye. The item reaches this speed with the deceleration or acceleration values. A value of Zero changes the speed instantly.

Jörg
The Following 2 Users Say Thank You to Jörg Vogel For This Useful Post:
syseo (02-12-2015)
  #3  
Old 02-12-2015
syseo's Avatar
syseo syseo is offline
Flexsim User
 
Join Date: Aug 2007
Location: Korea
Posts: 290
Downloads: 439
Uploads: 0
Thanks: 249
Thanked 63 Times in 41 Posts
Rep Power: 211
syseo has a spectacular aura aboutsyseo has a spectacular aura about
Default Dear. Vogel. Thanks, but It's same after three items moved.

Hi.

Thanks.
I set two or three photo-eyes in two lines.
Until two or three items moved on conveyors, It show some different moving feature

But after three items moved, moving speeds are same.

What's problem in my setting?
Attached Files
File Type: fsm AccDec_1.fsm (23.4 KB, 392 views)
  #4  
Old 02-17-2015
Anthony Johnson's Avatar
Anthony Johnson Anthony Johnson is offline
Manager of Product Development
 
Join Date: Jul 2007
Posts: 440
Downloads: 86
Uploads: 4
Thanks: 171
Thanked 899 Times in 288 Posts
Rep Power: 735
Anthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond repute
Default

I don't know exactly what else you would expect. If you set all conveyor speeds to 10, then even if their acc/dec is really small, they're eventually all going to get to a conveyor speed of 10, at which point all items will travel down the conveyor at the same rate.
Attached Files
File Type: fsm AccDec_1_with_Text.fsm (24.8 KB, 391 views)
  #5  
Old 02-18-2015
Jörg Vogel's Avatar
Jörg Vogel Jörg Vogel is offline
Flexsim User
 
Join Date: Sep 2007
Location: Hannover, Germany
Posts: 643
Downloads: 35
Uploads: 0
Thanks: 802
Thanked 665 Times in 410 Posts
Rep Power: 642
Jörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond reputeJörg Vogel has a reputation beyond repute
Unhappy

Hello Anthony,

you are looking at the conveyor module from the engineering view point.
If you set the conveyor to a new speed, then the motor has to accelarate or decelerate the conveyor wether there is an item on it or not. After some time the conveyor transports the items with the new set speed.
From the discrete event based view you can anticipate that there is a generell speed for every entering item, then the item travel with a new speed after a photo eye. We were able to implement such behaviour with the basic conveyor object. The other approach was setting a new speed with a command instantly. The effects of acceleration and deceleration are new. In the past was the focus on the item on the conveyor object not the object itself.
This new behaviour makes it difficult to work with the new module. Since it has got the bug with forking of items at the end of one conveyor into two different directions on other conveyors.
And we are not able to use the standard old conveyor objects from the library anymore if the conveyor module is loaded. If we load the module we are forced to use it. There is no choice. Something we have appreciated in the past. The possiblity to decide how to accomplish something is gone.
And the look of the object doesn't fit to the other objects. It is very abstract at the beginning. There are no legs, there is no texture. It is cold. It floats over the grid. To let it look like the standard objects we have to change it. Something we haven't had to do in the previous versions. Yes, I think we will love this object soon, but it looks strange with the other objects in a new model.

Jörg
The Following 3 Users Say Thank You to Jörg Vogel For This Useful Post:
syseo (02-20-2015)
  #6  
Old 02-18-2015
RalfGruber's Avatar
RalfGruber RalfGruber is offline
FlexSim Software Products
 
Join Date: Jul 2007
Location: Orem, UT, USA
Posts: 195
Downloads: 37
Uploads: 0
Thanks: 518
Thanked 294 Times in 124 Posts
Rep Power: 345
RalfGruber is a splendid one to beholdRalfGruber is a splendid one to beholdRalfGruber is a splendid one to beholdRalfGruber is a splendid one to beholdRalfGruber is a splendid one to beholdRalfGruber is a splendid one to beholdRalfGruber is a splendid one to behold
Default

Joerg,

one of the undocumented features of the new version is, that you can still use the "old" conveyor objects:
In the "Environment" tab of the "Global Preferences" GUI check the box for"Display Legacy Conveyors in the Library". This is switched off by default and switching it on will show the old conveyor objects in the drag-drop library grid as you are used to.

Best wishes

Ralf
FlexSim
The Following 2 Users Say Thank You to RalfGruber For This Useful Post:
Jörg Vogel (02-18-2015)
  #7  
Old 02-18-2015
Anthony Johnson's Avatar
Anthony Johnson Anthony Johnson is offline
Manager of Product Development
 
Join Date: Jul 2007
Posts: 440
Downloads: 86
Uploads: 4
Thanks: 171
Thanked 899 Times in 288 Posts
Rep Power: 735
Anthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond reputeAnthony Johnson has a reputation beyond repute
Default

Joerg,
I disagree with you on several points.

First, 90% of the time a conveyor system is a "pushed" system. What I mean by that is that the things on the system are usually pushed by the conveyor they're on, not by themselves. Therefore the things on the system follow the speed of the motor that is pushing them. If you want to change the speed of an item, you change the speed of the conveyor the item is on. If you have to do that in real life, why not have the simulation implement it that way as well? The only "standard conveyor" exceptions that I've seen so far is perhaps gravity flow conveyors and if you want to actually simulate slippage, but I think those are usually less critical elements of a simulation. So in implementing the new conveyor system where the items follow the speed of the conveyor, we are implementing to 90% of conveyor systems. The basic conveyor on the other hand implemented to 10% of cases, and for users to simulate the 90%, they often had to loop through the content of the conveyor to set item states whenever something changed. In the 10% of cases where items are actually self-driven, i.e. the motor is actually part of the item that is moving, I think the AGV module can cover a lot of that space (and if it doesn't, our development should be aimed to make it cover more). I think the AGV module and Conveyor modules split the space pretty well: if it's self-driven, use AGV's, if it's conveyor-driven, use conveyors. I do not regret the decision to make the new conveyor system conveyor-driven.

Secondly, we want people to use the new conveyor module, BY DEFAULT. So, when we asked ourselves, do we install the conveyor module by default, the answer was a definite yes. Then, do we leave in the old conveyors as well, so that new users will be presented with two completely different sets of conveyors to choose from in their library? To me the obvious answer to that is no, because we'd just be confusing new users. In addition, now that we have the new conveyor system, we want to push people to use the new system as much as possible, for tech support reasons. The fewer different types of objects that people are using (especially when their functionalities are redundant), the easier it is for our tech support staff to support our user base. So we want to get people up on the new stuff as quickly as possible. And I don't want to spend any more development time fixing bugs in the basic conveyor. For these reasons, I don't regret putting the new conveyor system in and removing the old conveyor system by default. Perhaps we're pushing our older users a bit fast, but that was our decision. Old users who have to have the old stuff can still tick the box in their preferences.

Regarding the look of the conveyors, I wanted to make the conveyors look awesome in render mode, with real rollers, not just a texture mapped onto a plane. The problem is, with FlexSim's current version of OpenGL, we can't use instanced rendering, which can significantly improve render speed for the rollers. Right now a big system in render mode will render pretty slow. So I decided to make it draw in "CAD" mode by default. Perhaps that will change once we get instanced rendering in. For now it is what it is. I personally think it looks clean and nice for laying a conveyor system out over a cad drawing. The only drawback may be that it's not consistent (although neither is our default flowitem box, or astar, or agv networks, or network nodes, or object connections...).

BTW, if you don't want the conveyor system to float above the grid, if you set the default conveyor type's leg height to 0, it will be put on the ground by default. Usually though I think you want it above the ground, because that's the way most conveyor systems are.

Last edited by Anthony Johnson; 02-18-2015 at 03:50 PM.
The Following 3 Users Say Thank You to Anthony Johnson For This Useful Post:
syseo (02-20-2015)


Thread Thread Starter Forum Replies Last Post
What's the difference between SQL mode and table mode when I use the command dbopen()? Rao Yuqing Q&A 3 01-07-2013 06:42 AM
difference between offset travel and travel? zhang xin Q&A 2 08-20-2012 07:11 AM
What is the difference between a Conveyor and Basic Conveyor shivrash Q&A 2 07-21-2009 04:09 AM
What is the difference of 'simulate' and 'emulate'? syseo Q&A 0 11-21-2007 04:12 PM


All times are GMT -6.
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Copyright 1993-2018 FlexSim Software Products, Inc.