Issues with simulating using laws of a geneva gear on CATIA DMU kinematic 1

[akman88]

Hi everyone,

This is my first post and I am very excited to be a part of this community! please bare with me for any mistakes.

I am trying to simulate geneva gear mechanism on CATIA DMU Kinematics, I am using this tutorial as a guide

https://www.youtube.com/watch?v=xDyy21rtUPE

I have managed to simulate the kinematics using laws as demonstrated in the video (the bigger disk is the geneva wheel and it is moved by the geneva crank)

[VIDEO]

https://www.dailymotion.com/video/x7925vb

[/VIDEO]

However, the issues I am having is based on the movement of the geneva wheel (the bigger wheel) where it kept resetting its position. The motion is given by the equation in this document on page 8 "the position of the geneva wheel is given by" -

http://gpusupercomputing.com/adarsh/Geneva.pdf

I have written the law as below

if Geneva_drive\KINTime <=90s

Geneva_drive\Commands\Command.2\Angle =-atan(sin(Geneva_drive\Commands\Command.1\Angle )/(c_distance /`radius _crank`-cos(Geneva_drive\Commands\Command.1\Angle ) ) )


else

{

if Geneva_drive\KINTime>=260s

Geneva_drive\Commands\Command.2\Angle =-atan(sin(Geneva_drive\Commands\Command.1\Angle )/(c_distance /`radius _crank`-cos(Geneva_drive\Commands\Command.1\Angle ) ) )

}


One thing I have realised is that, when the Geneva wheel starts moving again after the "else" function at 260s, the position of the Geneva wheel resets itself to the original position instead of continuing on from where it stopped. see video on daily motion for reference and you can see towards the end when it reset. You can also view the reset on this time series image.

https://imgur.com/a/4NMgepZ.

My question is: Is it possible to create law so that the Geneva wheel continues from the last known position at 41s rather than re-setting at 319s and provide a continuous motion?

If not, do you know any other way?


Thanks a lot for reading this! Looking forward to hearing your inputs.