3 DOF pneumatic simulator

[simulatorslo]

Hello!

We are a group of 3 high school students working on our 3-DOF simulator project.
The build is now finished and all that is left is making a great x-sim converter profile.

We have a testing profile made that uses our rear actuator to simulate acceleration and braking forces and a front left and a front right actuator to simulate lateral forces. It is a very basic profile but it did the job for testing the chasis strenght.

Everything was made from materials that our school could provide for us.
That is why we use pneumatic cylinders, a k8055n and have a low-end PC and display panel.
In the future if we will have enough funds (or hopefully get someone to sponsor our project) we will replace actuators with electrical ones and get a proper PC with eyefinity display setup.

Here is a video demonstration of how it currently looks and works:

you can even see our mentors helping us with some electronic issues

We already recieved a WHOLE LOT OF HELP on other threads of this forum and we are grateful for all of it!
However we would still like to ask you for more help or some of your ideas on how to do a proper x-sim converter profile.
If you could share screenshots of your working profiles, give links to useful existing threads on the forum or share your thoughts and tips on how to adjust ours that would be great.

Also a lot of thanks to sirnoname for making such great software and giving it out there for free!

EDIT:
We have two sets of valves but don't have two speeds set up in the converter yet!
We will try to do that tommorow so any tips on that would be much appreciated also!

[motiondave]

Looks good.
Just do not ask for funding , without considering the remarks back.
As for profiles , I will let some one else handle that.

[simulatorslo]

Just do not ask for funding , without considering the remarks back.

I see what you did there

[motiondave]

Just do not ask for funding , without considering the remarks back.

I see what you did there

not just me,
anyhoo...just ask questions as needed....
supply us with info properly and .....who knows...

[simulatorslo]

Okay thanks to yokoyoko I was able to make a basic profile that works as it should (I followed his youtube guide and some of his own tips).
Now the problem is when our pneumatic actuators try to center. They get into center position and then istead of stopping they go down waay too much and have to cener again. That makes the whole simulator move like a horse

Here is an example of how it does it:
http://www.youtube.com/watch?v=x9zIjkcndGI

[yokoyoko]

Hi all,

these students contacted me @ youtube. They are really nice guys with an impressiv motivated teacher! (I don't want to think back... burning some magnesium is the most thrillling experience of my school days )

I skyped with them today and wanted to help them on their profile BUT the profile seem not to be the key of the problem.

If you look at the last youtube video they posted - to me it seems like the simulator "centers" after every math round, or something else weird??? Can't really explain what is going on - I have to say that I know absolutly NOTHING about the k8055n! Somewhere in the Output setup I suggest the problem. Simulatorslo will post some screenshots later.

Perhaps someone more experienced can help these guys? Thx in advance.

edit: I watched your other videos - the motion in the first videos seems "ok" in comparision to the last video (can't see the screen but I guess). Did you change anything else than the profile between these videos?

Best regards
yokoyoko

[yokoyoko]

Could you please re upload your profile with only the math selected so we can see that at least.

- I reup just the math of their used profile. Its basicly the profile of the video tut (I didn't save program tasks - so no sliders).

I double checked ist and can't imagine the profile is causing the "horselike" behaviour.
But I agree

I can think of is that you might have the fall back to 0 function selected(washout)

it is looking like exact this is happening after every math-round.

I gave them an other profile - but school was closing in 15mins and I don't know if they had the time to test this.

reup_math.rar

(1.02 KiB) Downloaded 670 times

[yokoyoko]

I double checked

on third look ---> the effect 27 of you rear /zadnji/ axis is one time inverted and one time not. Normally both should to the same.

[simulatorslo]

I double checked

on third look ---> the effect 27 of you rear /zadnji/ axis is one time inverted and one time not. Normally both should to the same.

Yeah I think that was still messed up in the profile I sent you.
Unfortinatly I did not have any time to test the new profiles you sent me because we rather adjusted ours a little bit more for the weekend (there are so called "information days" when middle school students come to high schools they want to attend and they will be driving around in our simulator too).
So I won't be able to do any real adjustments to it untill next week

We reduced the problem where the cylinder tries to stop but instead drops down like 10cm (just a little bit so its not as noticable as before), but I beleave that is not the ultimate solution to our problem.

However here is a video update of how it currently works (profile attached):
http://www.youtube.com/watch?v=6q08ftX7L8s (the last actuator is not as much adjusted to remove the "horse riding effect" as the front ones where it is almost completley removed).

Here is a close up of how the same front actuator works in the same enviroment as the one in the video in the previus post but with our adjustments:
http://www.youtube.com/watch?v=0YKetkesai8 The big movements are caused by lateral and longitudinal forces, the movements that are only a few mm long are the ones that are "stopping" the actuator
This is however not so good for real driving because the movements are a little to slow because of the additional sequencesteps (you can see them in the screenshots or in the profile attached) so we found a "sweetspot" between a good motion behavour and stabilisation.

I think that math is not the problem (it does the same thing with any math setup) but maybe the output section is (maybe I have to adjust something special for penumatic cylinders?) or some k8055 setting.

In my observations it seems that when the actuator is in a such position that it should stop moving, the pot tells it that it went a little bit too high (like a few % of the path too much) and then it wants to lower it to the correct position again and the signal our Velleman k8055n sends to our actuator tells it exactly that - to lower again. But that signal is too long so it lowers the actuator too much. Therefore the actuator has to rise again to get to the proper position and when it gets raised a little bit too much the problem occurs all over again.

Also here are some screenshots of the current profile settings if the profile won't load for some reason:

NAMES OF OUR AXIS IN ENGLISH:
levi cilinder - left cylinder ; desni cilinder - right cylinder ; zadnji cilinder - rear cylinder

[simulatorslo]

but re reading your profile, there is a lot of pauses (ms of breaks between movements) that could be causing the issue to intensify

That was actually our "quickfix" for the issue which made it a little bit better. Thanks a lot for the reply it made things a lot clearer for us!
So from what you said I see no point in continuing with the Velleman (at least in the future).
Which board would you recommend to use that would act much better for pneumatics?