finding principal axis and moments of inertia tensor using eig function
조회 수: 41 (최근 30일)
이전 댓글 표시
Good Morning,
I am trying to calculate the principal moment of inertia as well as the principal axis of inertia.
If I am given a tensor matrix of the rotational moment of inertia:
I=[Jx -Jxy -Jxz; -Jxy Jy -Jyz; -Jxz -Jyz Jz];
And wish to find the principal moments and principal axis of inertia then I would simply use matlab eig.
[Axes,Moments]=eig(I);
And then diagonal of the Moments matrix is the principal moments. Now say I want to find the cosine of the angle of the principal axis of inertia with the three axes X,Y,Z that are center at the CG...how would I go about this?
Is it cos(Axes(:,1)), cos(Axes(:,2)), cos(Axes(:,3)??
Thank you.
댓글 수: 0
채택된 답변
Roger Stafford
2013년 8월 27일
"Is it cos(Axes(:,1)), cos(Axes(:,2)), cos(Axes(:,3)??"
No, the components of the eigenvectors themselves, Axes(:,1)), Axes(:,2), Axes(:,3), are already the cosines of the angles between the three principal axes of inertia respectively and the x, y, and z axes, provided the eigenvectors are normalized.
Of course there is an ambiguity about the sense of each of these vectors depending on which of two opposite directions are to be considered as the positive directions of these axes of inertia.
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 3-D Scene Control에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!