Numerical instability of spherical pendulum

1 次查看（过去 30 天）

显示更早的评论

Bas Siebers 2015-2-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/180298-numerical-instability-of-spherical-pendulum

评论： Mischa Kim 2015-2-26

采纳的回答： Mischa Kim

Hi,

I am trying to simulate a spherical pendulum. The equation of motion of the spherical pendulum are:

So far, I was able to simulate the equation of motion with a ode45 solver. However I experiencing numerical instabilities when the phi angle approach zero.

Does any one have an idea to get rid off these numerical instabilities?

Thank you in advance,

Bas

采纳的回答

Mischa Kim 2015-2-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/180298-numerical-instability-of-spherical-pendulum#answer_169289

Bas, the plus sign in your equation does look a bit strange. Shouldn't that be a minus instead?

8 个评论
显示 6更早的评论隐藏 6更早的评论

Bas Siebers 2015-2-26

编辑：Bas Siebers 2015-2-26

Thank you, I have still one question: Why is the line of the azimuth angle not straight? With other words, why is the velocity of the azimuth angle not constant? Because the initial value of the azimuth angle velocity is constant.