How to center pneumatic cylinder

[TheAmunraaa]

Hello!

My 2 schoolmates and me are building 3DoF pneumatic simulator as a school project.
We are using Velleman k8055n control board using six outputs for 3 axis in x-sim converter (previous profiler) and we are testing with LFS.
On the hardware side everything works because we can manipulate with our simulator using buttons connected to pneumatic valves but we have hard time with software since we still don't know how to set up math setup.
We would like our cylinders to travel to mid point at start and to go back to mid point on the straights after a corner.
When we go into a corner it all works fine (rear cylinder rises for braking, one of front cylinders rises and one lowers) but the trouble occurs when we exit a corner. Instead of going back to normal position (what we want to achieve) front 2 cylinders stay in their position like we were still in the corner which affects every corner afterwards.

We would like if someone can help us setup math and if possible help us find a way to center cylinders (we do have some sort of sensors/switches that we can attach to cylinders and are activated by pistons when they pass by)

Here is a picture of our simulator gutted so you can see cylinder arrangement:


Kind regards, Aleksander

P.S. English is not my primary language (I am from Slovenia) so if there is anything that you don't understand please let me *

[sirnoname]

Calibration setup in the converter.
On a start of the software it will go from maximum to minimum and tehn center.
You can load the RnR example and see the script in the calibration setup for your reference.

[TheAmunraaa]

Calibration setup in the converter.
On a start of the software it will go from maximum to minimum and tehn center.
You can load the RnR example and see the script in the calibration setup for your reference.

Thanks for the reply!

We already tried this calibration setup and it managed to extend cylinders to maximum and lowered them to minimum but then it extended them to maximum instead of centering them. Could it be that we don't have math setup or output setup dialed in correctly (looking at RnR output screen it seems rather complicated to what we got).
We have output setup same as here for one speed:
http://www.x-sim.de/manual/synaptrix.html

[sirnoname]

I have corrected your link to the original page. Do not use other instruction than the original manual!
It seems you have messed up minimum and maximum.
You need a pot, you need in the synaptrix a movment setup and then the calibration will work.
No math setup needed.
You can setup the middle position manual for your first tries. But remember to choose the correct minimum and maximum, i.e. connect your pot inverted.
The rnr setup is indeed much complex because it is a pulse setup which is able to make slow movements. But the calibration area is the same.

[TheAmunraaa]

Does the "pot" means "potentiometer"? If so no wonder it doesn't work because we don't have any. And even if we did we could only connect 2 on the velleman k8055n.

[Riton]

Hi, Yes , and yes, for more pots you need a VM140 or a second K8055N/VM110.

[sirnoname]

Hmmm, the complete page you said you have read does talk about how to callibrate the pot.
Also there are pictures which shows you that you can use any joystick as feedback pot.
Please read it again! The first step may help you.
After your calibration is working you can continue to the math section.

[TheAmunraaa]

Wow!
How could I overlook that -.-
By turning pots on k8055n on calibration it wants to stay in center.
Luckily we got a second k8055n from our friend so we could connect 3 pots.
Can anyone recommend a linear potentiometer with about 500mm of travel that would work with k8055n (I also hear that linear pots get quite pricy).

Kind regards, Aleksander

EDIT: Is it possible to center cylinders by only using sensors on the center of a cylinder that gives an digital signal to k8055n? Could we somehow tell converter that signal given is 50% value in refference input calibration?

[simulatorslo]

Hey!

I'm writing from our 'for-work' account and we have obtained pots and connected them. Now the problem that occured is, that when we connected the second velleman k8055n it did not recognise it even after the hardware rescan. The program recognises both velleman board if connected individually. Any solutions?

[sirnoname]

ID Jumper on the board must be different