Pulley with two hanging masses

Question

Pin-Hao Cheng 2020-5-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/522151-pulley-with-two-hanging-masses

回答： IGNACIO 2024-4-28

two_mass_pulley.slx

Hello all,

I have been trying to simulate the classic physics problem: a pulley with two hanging masses. I am not sure which part did I messed up, but even though I set the weight for the two masses significantly different, the slipping does not occur, and the body just swings left and right, but not one up one down as expected.

I have uploaded my simulink document below. I should also state that I am using gravity in the -Y direction.

Any help would be greatly appreciated!

3 个评论
显示 1更早的评论隐藏 1更早的评论

Eren Sarioglu 2020-8-23

I had the same problem, thanks a lot for the feedback !

Pin-Hao Cheng 2020-8-25

Hey Eren, glad I could help! Totally get that feeling when you found someone else is having the same problems with you! :)

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Pin-Hao Cheng 2020-11-17

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/522151-pulley-with-two-hanging-masses#answer_546798

See comment and attachment above.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

IGNACIO 2024-4-28

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/522151-pulley-with-two-hanging-masses#answer_1449026

two_mass_pulley0x2820x29_modified_mass_positions.slx

Hello,

I've tried the model above, just changed the masses initial position so they are vertically aligned with the pulley ends (see attachment). The behavior is strange:

Initial positions are fine, the centers of the masses are aligned with the pulley ends:
When starting simulation, the masses start to separate from each other, their frames not aligned with the cords, then they oscillate until a final position where one cord length is zero, an error condition is met, and the simulation is finished:
I tried to restrict the movement of the hanging masses by inserting joints (prismatic, etc.) between the belt cable ends and the hanging masses, but in this case I always get some kind of error (singularity, etc.).