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Question here

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^AR^B_{X' Y' Z'} ( \alpha, \beta, \gamma) =    \left[
         \begin{array}{ccc}
         c \beta c \gamma & - c \beta s \gamma & s \beta           \\
         s \alpha s \beta c \gamma + c \alpha s \gamma & - s \alpha s \beta s \gamma + c \alpha c \gamma & - s \alpha c \beta \\
         - c \alpha s \beta c \gamma + s \alpha s \gamma  & c \alpha s \beta s \gamma + s \alpha c \gamma & c \alpha c \beta
        \end{array}
    \right]

...

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body\alpha

...

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body\beta

...

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body\gamma

...

Info

This problem was contributed by Thomas Uchida at the University of Ottawa.


Frame A and point 

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bodyp
lie on the plane
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bodyz=0.3
:

Image Added

Note that unit vector 

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body--uriencoded--z_%7B\mathrm%7BA%7D%7D
is pointing out of the screen. The coordinates of point 
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bodyp
are (2.1, 0.5, 0) when expressed in frame A. Frame B lies in the same plane and has the orientation shown below:

Image Added


(a) Find the rotation matrix 

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body--uriencoded--%7B%7D%5e%7B\mathrm%7BA%7D%7D\!R_%7B\mathrm%7BB%7D%7D
that relates the orientation of frames A and B. Use any strategy to check your answer and explain why it is correct.

(b) For part (b) only, suppose the origins of frames A and B are coincident. Use your answer from part (a) and the expression 

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body--uriencoded--p_%7B\mathrm%7BA%7D%7D = %7B%7D%5e%7B\mathrm%7BA%7D%7D\!R_%7B\mathrm%7BB%7D%7D \ p_%7B\mathrm%7BB%7D%7D
to compute
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body--uriencoded--p_%7B\mathrm%7BB%7D%7D
. Recall that rotation matrices are orthogonal, which means that
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body--uriencoded--\left( %7B%7D%5e%7B\mathrm%7BA%7D%7D\!R_%7B\mathrm%7BB%7D%7D \right)%5e%7B-1%7D = \left( %7B%7D%5e%7B\mathrm%7BA%7D%7D\!R_%7B\mathrm%7BB%7D%7D \right)%5e%7B\operatorname%7BT%7D%7D
.

(c) Now suppose the origin of frame B is at 

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body--uriencoded--3.7 x_%7B\mathrm%7BA%7D%7D + 1.1 y_%7B\mathrm%7BA%7D%7D + 0 z_%7B\mathrm%7BA%7D%7D
relative to the origin of frame A. What is the transformation matrix 
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body--uriencoded--r_%7B11%7D
,
%7B%7D%5e%7B\mathrm%7BA%7D%7DT_%7B\mathrm%7BB%7D%7D
that relates frames A and B?

(d) Use your answer from part (c) and the expression below to compute

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body--uriencoded--r_%7B23%7D
, etc.) and clearly state any assumptions that you make
p_%7B\mathrm%7BB%7D%7D
:

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alignmentcenter
\begin{Bmatrix}p_{\mathrm{A}}\\1\end{Bmatrix} = {}^{\mathrm{A}}T_{\mathrm{B}} \begin{Bmatrix}p_{\mathrm{B}}\\1\end{Bmatrix}

(e) Sketch frame A, frame B, and point 

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bodyp
to confirm that your answer to part (d) is correct.


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titleSolution (only visible by instructors; please contact us to request access)

Include Page
S7.1 Extracting Euler angles from a rotation matrixS7.1 Extracting Euler angles from a rotation matrix3 Introduction to transformation matrices
S7.3 Introduction to transformation matrices