自动驾驶中的SLAM技术
第2章: 基础数学知识回顾
习题 1
分别使用左右扰动模型,计算 ∂ R − 1 p ∂ R \frac{\partial \mathbf{R}^{-1}\mathbf{p}}{\partial \mathbf{R}} ∂R∂R−1p。
左扰动模型
∂ R − 1 p ∂ R = lim δ ϕ → 0 ( E x p ( δ ϕ ) R ) − 1 p − R − 1 p δ ϕ = lim δ ϕ → 0 R − 1 E x p ( − δ ϕ ) p − R − 1 p δ ϕ = lim δ ϕ → 0 R − 1 ( I − δ ϕ ∧ ) p − R − 1 p δ ϕ = lim δ ϕ → 0 − R − 1 δ ϕ ∧ p δ ϕ = lim δ ϕ → 0 R − 1 p ∧ δ ϕ δ ϕ = R − 1 p ∧ \begin{align*} \frac{\partial \mathbf{R}^{-1}\mathbf{p}}{\partial \mathbf{R}} &= \underset{\delta \boldsymbol{\phi} \rightarrow 0}{\lim}\frac{\left( \mathrm{Exp}\left( \delta \boldsymbol{\phi} \right) \mathbf{R} \right) ^{-1}\mathbf{p}-\mathbf{R}^{-1}\mathbf{p}}{\delta \boldsymbol{\phi}} \\ &= \underset{\delta \boldsymbol{\phi} \rightarrow 0}{\lim}\frac{\mathbf{R}^{-1}\mathrm{Exp}\left( -\delta \boldsymbol{\phi} \right) \mathbf{p}-\mathbf{R}^{-1}\mathbf{p}}{\delta \boldsymbol{\phi}} \\ &= \underset{\delta \boldsymbol{\phi} \rightarrow 0}{\lim}\frac{\mathbf{R}^{-1}\left( \mathbf{I}-\delta \boldsymbol{\phi} ^{\land} \right) \mathbf{p}-\mathbf{R}^{-1}\mathbf{p}}{\delta \boldsymbol{\phi}} \\ &= \underset{\delta \boldsymbol{\phi} \rightarrow 0}{\lim}\frac{-\mathbf{R}^{-1}\delta \boldsymbol{\phi} ^{\land}\mathbf{p}}{\delta \boldsymbol{\phi}} \\ &= \underset{\delta \boldsymbol{\phi} \rightarrow 0}{\lim}\frac{\mathbf{R}^{-1}\mathbf{p}^{\land}\delta \boldsymbol{\phi}}{\delta \boldsymbol{\phi}} \\ &= \mathbf{R}^{-1}\mathbf{p}^{\land} \end{align*} ∂R∂R−1p=δϕ→0limδϕ(Exp(δϕ)R)−1p−R−1p=δϕ→0limδϕR−1Exp(−δϕ)p−R−1p=δϕ→0limδϕR−1(I−δϕ∧)p−R−1p=δϕ→0limδϕ−R−1δϕ∧p=δϕ→0limδϕR−1p∧δϕ=R−1p∧
右扰动模型
∂ R − 1 p ∂ R = lim δ ϕ → 0 ( R E x p ( δ ϕ ) ) − 1 p − R − 1 p δ ϕ = lim δ ϕ → 0 E x p ( − δ ϕ ) R − 1 p − R − 1 p δ ϕ = lim