Over constraints error during building the kinematics(joints) 2

[Abdelrahman bedo]

Greetings
I'm totally new to delmia software ,I started a week ago .
I have used this software to simulate a hybrid robot and had a simple guide from a thesis(chalmers).
In the beginning it was good until this error showed out of the blue "the mechanism is over constrained".
I searched the thesis well and find this paragraph "The reason of such a case is usually resulting from the fact that the algorithm behind DELMIA V5’s forward kinematics is not able to find a point in the working space to create the necessary constraints for the joint. In order to overcome such a problem, users can easily drag/rotate the respective part to a point that is close to the center of prospective joint. Usually, the relocation of these parts results in the successful assembly; however, the outcome may differ from what users expect. Even if the over-constraint case did not happen, the algorithm described above can cause unexpected problems such as the case in which the mobile parts of the robot are diving through each other"
I tried to do this but it doesn't change at all,so I'm grateful if someone can help me.

here is a pic of

I also uploaded file of robot and parts :

https://drive.google.com/open?id=1uZGOv-S5emuoAWGCrBFBXksHHK8PysqM

 

[Abdelrahman bedo]

seems I came to the wrong place

 

[LWolf]

your mechanism still has 6 degrees of freedom?
and you have already three commands. try placing some rigid (fixed) constraints to get rid of the excessive DOF.

regards,
LWolf

 

[Abdelrahman bedo]

Hey LWolf
I tried to make the moblie platform rigid but one joint is impossible to create wherever I place it .
May I ask you to explain more ,I'm just a beginner .
if you can show me an example or the way to do it ,I'd be grateful .
my updated scene :

https://drive.google.com/open?id=1WC43BCXdY8WgUTdiBWnParc-jvlSrkoL

 

[Abdelrahman bedo]

guys please help me ,I'm running out of time and can't solve this problem yet .

 

[Abdelrahman bedo]

update :I have passed this error but now I can't simulate the mechanism and DOF=undefined ?!

 

[dougsnell]

from that display, it looks like the joint Prismatic.4 has no connection to geometry. Removing that would be the first step.

 

[Abdelrahman bedo]

yes when I modified other joint, seems that prismatic joint to be affected , I removed it but now I'm still at that over constrain error .

 

[Abdelrahman bedo]

update: I managed to solve this problem and just after I made last joint successfully ,I saw "too many commands " .
when I try to jog mechanism error shows up "unable to build the handle" although DOF=0. , so what should I do now ? .

 

[LWolf]

remove all your commands... how many DOF do you get then?...

regards,
LWolf

 

[Abdelrahman bedo]

when I remove all my commands then I have DOF=2

I uploaded a small video to explain :

https://drive.google.com/open?id=1o881QFBAyDwT0Unc4d-s6qxkgKpkO_VM

 

[LWolf]

so, you should implement two commands, not three. each command takes care of one DOF...

regards,
LWolf

 

[Abdelrahman bedo]

okay now I can simulate the platform with just 2 arms connected to it but what about the third arm ?
what should I do to provide 3 dof so 3 commands should be implemented ?
also for this 2 dof ,I can choose any of the three arms to activate but seems when I choose arm 2 with one of the other arms ,it doesn't act as wanted"it should move the mechanism up and down not right & left "

video explaining the motion :

https://www.youtube.com/watch?v=ofbftOPjcW0

 

[Abdelrahman bedo]

update:I tried to add another joints or redo the existing joints by another way but failed too.

 

[Abdelrahman bedo]

update: the reason why there just 2 dof is because to arms move together when I jog one of them , like switching on motor of prismatic joint then the other one works too

 

[Abdelrahman bedo]

what should I do ?

 

[Abdelrahman bedo]

it has been than more week since anyone replayed here , and I still can't solve the problem