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[足式机器人]Part3 机构运动学与动力学分析与建模 Ch00-2(2) 质量刚体的在坐标系下运动

2026/9/26 11:46:44 拓冰建站 浏览量
[足式机器人]Part3 机构运动学与动力学分析与建模 Ch00-2(2) 质量刚体的在坐标系下运动

本文仅供学习使用,总结很多本现有讲述运动学或动力学书籍后的总结,从矢量的角度进行分析,方法比较传统,但更易理解,并且现有的看似抽象方法,两者本质上并无不同。

2024年底本人学位论文发表后方可摘抄
若有帮助请引用
本文参考:
黎 旭,陈 强 洪,甄 文 强 等.惯 性 张 量 平 移 和 旋 转 复 合 变 换 的 一 般 形 式 及 其 应 用[J].工 程 数 学 学 报,2022,39(06):1005-1011.

食用方法
质量点的动量与角动量
刚体的动量与角动量——力与力矩的关系
惯性矩阵的表达与推导——在刚体运动过程中的作用
惯性矩阵在不同坐标系下的表达
务必自己推导全部公式,并理解每个符号的含义

机构运动学与动力学分析与建模 Ch00-2质量刚体的在坐标系下运动Part2

      • 2.2.3 欧拉方程 Euler equation


2.2.3 欧拉方程 Euler equation

对式 H ⃗ Σ M / O F \vec{H}_{\Sigma _{\mathrm{M}}/\mathrm{O}}^{F} H ΣM​/OF​进一步分析,有:
H ⃗ Σ M / O F = ∫ R ⃗ O P i F × ( d m i ⋅ d R ⃗ P i F d t ) = ∫ ( ( R ⃗ P i F − R ⃗ O F ) × V ⃗ P i F ) d m i = ∫ ( R ⃗ P i F × V ⃗ P i F ) d m i − ∫ ( R ⃗ O F × V ⃗ P i F ) d m i = H ⃗ Σ M F − R ⃗ O F × P ⃗ G F \begin{split} \vec{H}_{\Sigma _{\mathrm{M}}/\mathrm{O}}^{F}&=\int{\vec{R}_{\mathrm{OP}_{\mathrm{i}}}^{F}\times \left( \mathrm{d}m_i\cdot \frac{\mathrm{d}\vec{R}_{\mathrm{P}_{\mathrm{i}}}^{F}}{\mathrm{d}t} \right)}=\int{\left( \left( \vec{R}_{\mathrm{P}_{\mathrm{i}}}^{F}-\vec{R}_{\mathrm{O}}^{F} \right) \times \vec{V}_{\mathrm{P}_{\mathrm{i}}}^{F} \right) \mathrm{d}m_i} \\ &=\int{\left( \vec{R}_{\mathrm{P}_{\mathrm{i}}}^{F}\times \vec{V}_{\mathrm{P}_{\mathrm{i}}}^{F} \right) \mathrm{d}m_i}-\int{\left( \vec{R}_{\mathrm{O}}^{F}\times \vec{V}_{\mathrm{P}_{\mathrm{i}}}^{F} \right) \mathrm{d}m_i} \\ &=\vec{H}_{\Sigma _{\mathrm{M}}}^{F}-\vec{R}_{\mathrm{O}}^{F}\times \vec{P}_{\mathrm{G}}^{F} \end{split} H ΣM​/OF​​=∫R OPi​F​×(dmi​⋅dtdR Pi​F​​)=∫((R Pi​F​−R OF​)×V Pi​F​)dmi​=∫(R Pi​F​×V Pi​F​)dmi​−∫(R OF​×V Pi​F​)dmi​=H ΣM​F​−R OF​×P GF​​
对上式进一步求导,则有:
d H ⃗ Σ M / O F d t = d H ⃗ Σ M F d t − d ( R ⃗ O F × P ⃗ G F ) d t = d H ⃗ Σ M F d t − V ⃗ O F × P ⃗ G F − m t o t a l ⋅ R ⃗ O F × a ⃗ G F \frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}/\mathrm{O}}^{F}}{\mathrm{d}t}=\frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}}^{F}}{\mathrm{d}t}-\frac{\mathrm{d}\left( \vec{R}_{\mathrm{O}}^{F}\times \vec{P}_{\mathrm{G}}^{F} \right)}{\mathrm{d}t}=\frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}}^{F}}{\mathrm{d}t}-\vec{V}_{\mathrm{O}}^{F}\times \vec{P}_{\mathrm{G}}^{F}-m_{\mathrm{total}}\cdot \vec{R}_{\mathrm{O}}^{F}\times \vec{a}_{\mathrm{G}}^{F} dtdH ΣM​/OF​​=dtdH ΣM​F​​−dtd(R OF​×P GF​)​=dtdH ΣM​F​​−V OF​×P GF​−mtotal​⋅R OF​×a GF​
其中:
H ⃗ Σ M F = ∫ R ⃗ P i F × p ⃗ P i F = ∫ ( R ⃗ G F + R ⃗ G P i F ) × ( d m i ⋅ ( V ⃗ G F + V ⃗ G P i F ) ) = ∫ R ⃗ G F × V ⃗ G F d m i ⏟ m t o t a l ⋅ R ⃗ G F × V ⃗ G F + ∫ R ⃗ G F × V ⃗ G P i F d m i ⏟ 0 + ∫ R ⃗ G P i F × V ⃗ G F d m i ⏟ 0 + ∫ R ⃗ G P i F × V ⃗ G P i F d m i ⏟ ∫ R ⃗ G P i F × ( ω ⃗ M F × R ⃗ G P i F ) d m i = m t o t a l ⋅ R ⃗ G F × V ⃗ G F + ∫ R ⃗ G P i F × ( ω ⃗ M F × R ⃗ G P i F ) d m i = m t o t a l ⋅ R ⃗ G F × V ⃗ G F + ∫ ( R ⃗ G P i F ⋅ R ⃗ G P i F ) ω ⃗ M F d m i − ∫ ( R ⃗ G P i F ⋅ ω ⃗ M F ) R ⃗ G P i F d m i \begin{split} \vec{H}_{\Sigma _{\mathrm{M}}}^{F}&=\int{\vec{R}_{\mathrm{P}_{\mathrm{i}}}^{F}\times \vec{p}_{\mathrm{P}_{\mathrm{i}}}^{F}}=\int{\left( \vec{R}_{\mathrm{G}}^{F}+\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \times \left( \mathrm{d}m_i\cdot \left( \vec{V}_{\mathrm{G}}^{F}+\vec{V}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \right)} \\ &=\begin{array}{c} \underbrace{\int{\vec{R}_{\mathrm{G}}^{F}\times \vec{V}_{\mathrm{G}}^{F}}\mathrm{d}m_i}\\ m_{\mathrm{total}}\cdot \vec{R}_{\mathrm{G}}^{F}\times \vec{V}_{\mathrm{G}}^{F}\\ \end{array}+\begin{array}{c} \underbrace{\int{\vec{R}_{\mathrm{G}}^{F}\times \vec{V}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_i}\\ 0\\ \end{array}+\begin{array}{c} \underbrace{\int{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\times \vec{V}_{\mathrm{G}}^{F}}\mathrm{d}m_i}\\ 0\\ \end{array}+\begin{array}{c} \underbrace{\int{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\times \vec{V}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_i}\\ \int{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\times \left( \vec{\omega}_{\mathrm{M}}^{F}\times \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right)}\mathrm{d}m_i\\ \end{array} \\ &=m_{\mathrm{total}}\cdot \vec{R}_{\mathrm{G}}^{F}\times \vec{V}_{\mathrm{G}}^{F}+\int{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\times \left( \vec{\omega}_{\mathrm{M}}^{F}\times \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right)}\mathrm{d}m_i \\ &=m_{\mathrm{total}}\cdot \vec{R}_{\mathrm{G}}^{F}\times \vec{V}_{\mathrm{G}}^{F}+\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \vec{\omega}_{\mathrm{M}}^{F}}\mathrm{d}m_i-\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_i \end{split} H ΣM​F​​=∫R Pi​F​×p ​Pi​F​=∫(R GF​+R GPi​F​)×(dmi​⋅(V GF​+V GPi​F​))= ∫R GF​×V GF​dmi​​mtotal​⋅R GF​×V GF​​+ ∫R GF​×V GPi​F​dmi​​0​+ ∫R GPi​F​×V GF​dmi​​0​+ ∫R GPi​F​×V GPi​F​dmi​​∫R GPi​F​×(ω MF​×R GPi​F​)dmi​​=mtotal​⋅R GF​×V GF​+∫R GPi​F​×(ω MF​×R GPi​F​)dmi​=mtotal​⋅R GF​×V GF​+∫(R GPi​F​⋅R GPi​F​)ω MF​dmi​−∫(R GPi​F​⋅ω MF​)R GPi​F​dmi​​
将 H ⃗ Σ M F \vec{H}_{\Sigma _{\mathrm{M}}}^{F} H ΣM​F​进一步求导,则有:
d H ⃗ Σ M F d t = { R ⃗ G F × m t o t a l ⋅ a ⃗ G F + 2 ∫ ( V ⃗ P i F ⋅ R ⃗ G P i F ) ω ⃗ M F d m i + ∫ ( R ⃗ G P i F ⋅ R ⃗ G P i F ) α ⃗ M F d m i − ∫ ( V ⃗ G P i F ⋅ ω ⃗ M F ) R ⃗ G P i F d m i − ∫ ( R ⃗ G P i F ⋅ α ⃗ M F ) R ⃗ G P i F d m i − ∫ ( R ⃗ G P i F ⋅ ω ⃗ M F ) V ⃗ G P i F d m i = { R ⃗ G F × m t o t a l ⋅ a ⃗ G F + ( ∫ ( R ⃗ G P i F ⋅ R ⃗ G P i F ) α ⃗ M F d m i − ∫ ( R ⃗ G P i F ⋅ α ⃗ M F ) R ⃗ G P i F d m i ) − ∫ ( R ⃗ G P i F ⋅ ω ⃗ M F ) ( ω ⃗ M F × R ⃗ G P i F ) d m i = { R ⃗ G F × m t o t a l ⋅ a ⃗ G F + ( ∫ ( R ⃗ G P i F T R ⃗ G P i F ) ⋅ E 3 × 3 α ⃗ M F d m i − ∫ ( R ⃗ G P i F T α ⃗ M F ) R ⃗ G P i F d m i ) − ∫ ( R ⃗ G P i F T ω ⃗ M F ) ( ω ⃗ M F × R ⃗ G P i F ) d m i = { R ⃗ G F × m t o t a l ⋅ a ⃗ G F + α ⃗ M F ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T ) d m i − ω ⃗ M F × ( ∫ ( R ⃗ G P i F R ⃗ G P i F T ) d m i ⋅ ω ⃗ M F ) \begin{split} \frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}}^{F}}{\mathrm{d}t}&=\begin{cases} \vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+2\int{\left( \vec{V}_{\mathrm{P}_{\mathrm{i}}}^{F}\cdot \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \vec{\omega}_{\mathrm{M}}^{F}}\mathrm{d}m_{\mathrm{i}}+\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \vec{\alpha}_{\mathrm{M}}^{F}}\mathrm{d}m_{\mathrm{i}}\\ -\int{\left( \vec{V}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_{\mathrm{i}}-\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\alpha}_{\mathrm{M}}^{F} \right) \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_{\mathrm{i}}-\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \vec{V}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_{\mathrm{i}}\\ \end{cases} \\ &=\begin{cases} \vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\left( \int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \vec{\alpha}_{\mathrm{M}}^{F}}\mathrm{d}m_{\mathrm{i}}-\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\alpha}_{\mathrm{M}}^{F} \right) \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_{\mathrm{i}} \right)\\ -\int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \left( \vec{\omega}_{\mathrm{M}}^{F}\times \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \mathrm{d}m_{\mathrm{i}}}\\ \end{cases} \\ &=\begin{cases} \vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\left( \int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \cdot E^{3\times 3}\vec{\alpha}_{\mathrm{M}}^{F}}\mathrm{d}m_{\mathrm{i}}-\int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{\alpha}_{\mathrm{M}}^{F} \right) \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}\mathrm{d}m_{\mathrm{i}} \right)\\ -\int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{\omega}_{\mathrm{M}}^{F} \right) \left( \vec{\omega}_{\mathrm{M}}^{F}\times \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F} \right) \mathrm{d}m_{\mathrm{i}}}\\ \end{cases} \\ &=\begin{cases} \vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\vec{\alpha}_{\mathrm{M}}^{F}\int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\\ -\vec{\omega}_{\mathrm{M}}^{F}\times \left( \int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right)\\ \end{cases} \end{split} dtdH ΣM​F​​​=⎩ ⎨ ⎧​R GF​×mtotal​⋅a GF​+2∫(V Pi​F​⋅R GPi​F​)ω MF​dmi​+∫(R GPi​F​⋅R GPi​F​)α MF​dmi​−∫(V GPi​F​⋅ω MF​)R GPi​F​dmi​−∫(R GPi​F​⋅α MF​)R GPi​F​dmi​−∫(R GPi​F​⋅ω MF​)V GPi​F​dmi​​=⎩ ⎨ ⎧​R GF​×mtotal​⋅a GF​+(∫(R GPi​F​⋅R GPi​F​)α MF​dmi​−∫(R GPi​F​⋅α MF​)R GPi​F​dmi​)−∫(R GPi​F​⋅ω MF​)(ω MF​×R GPi​F​)dmi​​=⎩ ⎨ ⎧​R GF​×mtotal​⋅a GF​+(∫(R GPi​F​TR GPi​F​)⋅E3×3α MF​dmi​−∫(R GPi​F​Tα MF​)R GPi​F​dmi​)−∫(R GPi​F​Tω MF​)(ω MF​×R GPi​F​)dmi​​=⎩ ⎨ ⎧​R GF​×mtotal​⋅a GF​+α MF​∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T)dmi​−ω MF​×(∫(R GPi​F​R GPi​F​T)dmi​⋅ω MF​)​​
其中:
⇒ − ω ⃗ M F × ∫ ( R ⃗ G P i F R ⃗ G P i F T ) d m i ⋅ ω ⃗ M F = ω ⃗ M F × ( ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T − R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 ) d m i ⋅ ω ⃗ M F ) = ω ⃗ M F × ( ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T ) d m i ⋅ ω ⃗ M F ) − ω ⃗ M F × ( ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 ) d m i ⋅ ω ⃗ M F ) ⏟ 0 \begin{split} \Rightarrow &-\vec{\omega}_{\mathrm{M}}^{F}\times \int{\left( \vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \\ &=\vec{\omega}_{\mathrm{M}}^{F}\times \left( \int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}-{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \\ &=\vec{\omega}_{\mathrm{M}}^{F}\times \left( \int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) -\begin{array}{c} \underbrace{\vec{\omega}_{\mathrm{M}}^{F}\times \left( \int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) }\\ 0\\ \end{array} \end{split} ⇒​−ω MF​×∫(R GPi​F​R GPi​F​T)dmi​⋅ω MF​=ω MF​×(∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T−R GPi​F​TR GPi​F​⋅E3×3)dmi​⋅ω MF​)=ω MF​×(∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T)dmi​⋅ω MF​)− ω MF​×(∫(R GPi​F​TR GPi​F​⋅E3×3)dmi​⋅ω MF​)​0​​

将上两式进行汇总,可得:
⇒ d H ⃗ Σ M F d t = { R ⃗ G F × m t o t a l ⋅ a ⃗ G F + ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T ) d m i α ⃗ M F + ω ⃗ M F × ( ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T ) d m i ⋅ ω ⃗ M F ) = R ⃗ G F × m t o t a l ⋅ a ⃗ G F + [ I ] Σ M / G F α ⃗ M F + ω ⃗ M F × ( [ I ] Σ M / G F ⋅ ω ⃗ M F ) \begin{split} \Rightarrow \frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}}^{F}}{\mathrm{d}t}&=\begin{cases} \vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\vec{\alpha}_{\mathrm{M}}^{F}\\ +\vec{\omega}_{\mathrm{M}}^{F}\times \left( \int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_{\mathrm{i}}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right)\\ \end{cases} \\ &=\vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\vec{\alpha}_{\mathrm{M}}^{F}+\vec{\omega}_{\mathrm{M}}^{F}\times \left( \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \end{split} ⇒dtdH ΣM​F​​​=⎩ ⎨ ⎧​R GF​×mtotal​⋅a GF​+∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T)dmi​α MF​+ω MF​×(∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T)dmi​⋅ω MF​)​=R GF​×mtotal​⋅a GF​+[I]ΣM​/GF​α MF​+ω MF​×([I]ΣM​/GF​⋅ω MF​)​

其中:
[ I ] Σ M / G F = ∫ ( R ⃗ G P i F T R ⃗ G P i F ⋅ E 3 × 3 − R ⃗ G P i F R ⃗ G P i F T ) d m i \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}=\int{\left( {\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}}\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}\cdot E^{3\times 3}-\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}{\vec{R}_{\mathrm{GP}_{\mathrm{i}}}^{F}}^{\mathrm{T}} \right)}\mathrm{d}m_i [I]ΣM​/GF​=∫(R GPi​F​TR GPi​F​⋅E3×3−R GPi​F​R GPi​F​T)dmi​

[ I ] Σ M / G F \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F} [I]ΣM​/GF​被称为惯性矩阵inertia matrix(或称为惯量矩阵),为该物体在固定坐标系下相对于质心点 G G G的惯性张量。

进而可知:
d H ⃗ Σ M F d t = M ⃗ Σ M F = ∫ R ⃗ P i F × d F ⃗ P i F = R ⃗ G F × m t o t a l ⋅ a ⃗ G F + [ I ] Σ M / G F α ⃗ M F + ω ⃗ M F × ( [ I ] Σ M / G F ⋅ ω ⃗ M F ) \frac{\mathrm{d}\vec{H}_{\Sigma _{\mathrm{M}}}^{F}}{\mathrm{d}t}=\vec{M}_{\Sigma _{\mathrm{M}}}^{F}=\int{\vec{R}_{\mathrm{P}_{\mathrm{i}}}^{F}\times \mathrm{d}\vec{F}_{\mathrm{P}_{\mathrm{i}}}^{F}}=\vec{R}_{\mathrm{G}}^{F}\times m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F}+\left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\vec{\alpha}_{\mathrm{M}}^{F}+\vec{\omega}_{\mathrm{M}}^{F}\times \left( \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) dtdH ΣM​F​​=M ΣM​F​=∫R Pi​F​×dF Pi​F​=R GF​×mtotal​⋅a GF​+[I]ΣM​/GF​α MF​+ω MF​×([I]ΣM​/GF​⋅ω MF​)
上式被称为:欧拉方程在惯性坐标系下相对固定点的表达式;当固定点与质心点重合时(此时G点为固定点),则有:
M ⃗ Σ M / G F = M ⃗ Σ M F − R ⃗ G F × ( m t o t a l ⋅ a ⃗ G F ) = R ⃗ G F × ( m t o t a l ⋅ a ⃗ G F ) + [ I ] Σ M / G F α ⃗ M F + ω ⃗ M F × ( [ I ] Σ M / G F ⋅ ω ⃗ M F ) − R ⃗ G F × ( m t o t a l ⋅ a ⃗ G F ) = [ I ] Σ M / G F α ⃗ M F + ω ⃗ M F × ( [ I ] Σ M / G F ⋅ ω ⃗ M F ) \begin{split} \vec{M}_{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}&=\vec{M}_{\Sigma _{\mathrm{M}}}^{F}-\vec{R}_{\mathrm{G}}^{F}\times \left( m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F} \right) \\ &=\vec{R}_{\mathrm{G}}^{F}\times \left( m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F} \right) +\left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\vec{\alpha}_{\mathrm{M}}^{F}+\vec{\omega}_{\mathrm{M}}^{F}\times \left( \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) -\vec{R}_{\mathrm{G}}^{F}\times \left( m_{\mathrm{total}}\cdot \vec{a}_{\mathrm{G}}^{F} \right) \\ &=\left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\vec{\alpha}_{\mathrm{M}}^{F}+\vec{\omega}_{\mathrm{M}}^{F}\times \left( \left[ I \right] _{\Sigma _{\mathrm{M}}/\mathrm{G}}^{F}\cdot \vec{\omega}_{\mathrm{M}}^{F} \right) \end{split} M ΣM​/GF​​=M ΣM​F​−R GF​×(mtotal​⋅a GF​)=R GF​×(mtotal​⋅a GF​)+[I]ΣM​/GF​α MF​+ω MF​×([I]ΣM​/GF​⋅ω MF​)−R GF​×(mtotal​⋅a GF​)=[I]ΣM​/GF​α MF​+ω MF​×([I]ΣM​/GF​⋅ω MF​)​
此时为固定坐标系下相对固定点质心 G G G求解的欧拉方程。