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Documentation of the rotational motion of reference frames #3619

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merged 14 commits into from
May 1, 2023

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@pleroy pleroy commented Apr 26, 2023

@pleroy pleroy changed the title Documentation of the rotation motion of reference frames Documentation of the rotational motion of reference frames Apr 27, 2023
\end{equation}
Injecting these expressions in the derivative formula (\ref{eqndv}) makes it possible to compute the trihedron of the derivatives $\pa{\dot{\vf}, \dot{\vn}, \dot{\vb}}$ of (\ref{eqnfbn}). The angular velocity is then written:
\[
\VectorSymbol{\gw} = \pascal{\scal{\dot{\vn}}{\vb}} \vf + \pascal{\scal{\dot{\vb}}{\vf}} \vn + \pascal{\scal{\dot{\vf}}{\vn}} \vb
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Document the derivation of 𝝎.

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Done.

\end{equation}
Injecting these expressions in the second derivative formula (\ref{eqnddv}) makes it possible to compute the trihedron of the second derivatives $\pa{\ddot{\vf}, \ddot{\vn}, \ddot{\vb}}$ of (\ref{eqnfbn}). The angular acceleration is then written:
\begin{align*}
\dot{\VectorSymbol{\gw}} &= \pascal{\scal{\ddot{\vn}}{\vb}} \vf + \pascal{\scal{\dot{\vn}}{\dot{\vb}}} \vf + \pascal{\scal{\dot{\vn}}{\vb}} \dot{\vf} \\
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Document the derivation of 𝝎̇.

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The derivation of 𝝎̇ is rather obvious once the formula for 𝝎 is known. It's just the formula for the derivative of products.

&+ \pascal{\scal{\ddot{\vf}}{\vn}} \vb + \pascal{\scal{\dot{\vf}}{\dot{\vn}}} \vb + \pascal{\scal{\dot{\vf}}{\vn}} \dot{\vb}
\end{align*}

\section*{Jerk}
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This is wrong.

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Fixed.

\pderiv{\vq}{\VectorSymbol{\gG}} \deriv{t}{\vq} +
\sum{k = 1}[n] \pderiv{\vq_k}{\VectorSymbol{\gG}} \deriv{t}{\vq_k} =
\pderiv{\vq}{\VectorSymbol{\gG}} \dot{\vq} +
\sum{k = 1}[n] \pderiv{\vq_k}{\VectorSymbol{\gG}} \dot{\vq_k}
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@eggrobin eggrobin May 1, 2023

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Put the dot over the q, rather than sticking out over the index: \dot{\vq}_k

@eggrobin eggrobin added the LGTM label May 1, 2023
@pleroy pleroy merged commit 61b2b3c into mockingbirdnest:master May 1, 2023
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2 participants