残差
由预积分
[pwbjqwbjvjwbjabjg]=[pwbi+viwΔt−12gwΔt2+qwbiαbibjqwbiqbibjviw−gwΔt+qwbiβbibjbiabig]
\left[\begin{array}{c}
\mathbf{p}_{w b_{j}} \\
\mathbf{q}_{w b_{j}} \\
\mathbf{v}_{j}^{w} \\
\mathbf{b}_{j}^{a} \\
\mathbf{b}_{j}^{g}
\end{array}\right]=\left[\begin{array}{c}
\mathbf{p}_{w b_{i}}+\mathbf{v}_{i}^{w} \Delta t-\frac{1}{2} \mathbf{g}^{w} \Delta t^{2}+\mathbf{q}_{w b_{i}} \boldsymbol{\alpha}_{b_{i} b_{j}} \\
\mathbf{q}_{w b_{i}} \mathbf{q}_{b_{i} b_{j}} \\
\mathbf{v}_{i}^{w}-\mathbf{g}^{w} \Delta t+\mathbf{q}_{w b_{i}} \boldsymbol{\beta}_{b_{i} b_{j}} \\
\mathbf{b}_{i}^{a} \\
\mathbf{b}_{i}^{g}
\end{array}\right]
pwbjqwbjvjwbjabjg=pwbi+viwΔt−21gwΔt2+qwbiαbibjqwbiqbibjviw−gwΔt+qwbiβbibjbiabig
把上式左侧状态移到右侧,残差为:
[rprqrvrbarby]=[pwbj−pwbi−viwΔt+12gwΔt2−qwbiαbibj2[qbibj∗⊗(qwbi∗⊗qwbj)]xyzvjw−viw+gwΔt−qwbiβbibjbja−biabjg−big]
\left[\begin{array}{c}
\mathbf{r}_{p} \\
\mathbf{r}_{q} \\
\mathbf{r}_{v} \\
\mathbf{r}_{b a} \\
\mathbf{r}_{b y}
\end{array}\right]=\left[\begin{array}{c}
\mathbf{p}_{w b_{j}}-\mathbf{p}_{w b_{i}}-\mathbf{v}_{i}^{w} \Delta t+\frac{1}{2} \mathbf{g}^{w} \Delta t^{2}-\mathbf{q}_{w b_{i}} \boldsymbol{\alpha}_{b_{i} b_{j}} \\
2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} \\
\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t-\mathbf{q}_{w b_{i}} \boldsymbol{\beta}_{b_{i} b_{j}} \\
\mathbf{b}_{j}^{a}-\mathbf{b}_{i}^{a} \\
\mathbf{b}_{j}^{g}-\mathbf{b}_{i}^{g}
\end{array}\right]
rprqrvrbarby=pwbj−pwbi−viwΔt+21gwΔt2−qwbiαbibj2[qbibj∗⊗(qwbi∗⊗qwbj)]xyzvjw−viw+gwΔt−qwbiβbibjbja−biabjg−big
其中, 关于姿态残差 rq\mathbf{r}_{q}rq部分,需要将四元数拆开来看, 根据四元数与等轴旋转矢量ϕ\phiϕ的关系:
q=cosϕ2+(uxi+uyj+uzk)sinϕ2=[cos(ϕ/2)usin(ϕ/2)]
\mathbf{q}=\cos \frac{\phi}{2}+\left(u_{x} i+u_{y} j+u_{z} k\right) \sin \frac{\phi}{2}=\left[\begin{array}{c}
\cos (\phi / 2) \\
\mathbf{u} \sin (\phi / 2)
\end{array}\right]
q=cos2ϕ+(uxi+uyj+uzk)sin2ϕ=[cos(ϕ/2)usin(ϕ/2)]
等效旋转矢量可以用向量 ϕ\phiϕ,并用单位向量u\mathbf{u}u表示它的朝向, ϕ\phiϕ表示它的大小, 因此有: ϕ=ϕu\phi=\phi \boldsymbol{u}ϕ=ϕu 其中,
rq=2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz
\mathbf{r}_{q}=2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z}
rq=2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz
[]xyz[]_{x y z}[]xyz就是取四元数的虚部 usin(ϕ/2)\mathbf{u} \sin (\phi / 2)usin(ϕ/2), 特别的,当旋转角度ϕ\phiϕ是小量时,sin(ϕ/2)≈ϕ/2\sin (\phi / 2) \approx \phi / 2sin(ϕ/2)≈ϕ/2 , 对其乘个 2 , 就得到了上面的姿态残差rq\mathbf{r}_{q}rq。
在上面的预积分误差中, 和预积分相关的量, 仍然与上一时刻的姿态有关, 如 rp\mathbf{r}_{p}rp, rv\mathbf{r}_{v}rv, 无法直接加减(啥意思), 因此, 把预积分残差进行修正, 得到:
[rprqrvrbarbg]=[qwbi∗(pwbj−pwbi−viwΔt+12gwΔt2)−αbibj2[qbibj∗⊗(qwbi∗⊗qwbj)]xyzqwbi∗(vjw−viw+gwΔt)−βbibjbja−biabjg−big]
\left[\begin{array}{c}
\mathbf{r}_{p} \\
\mathbf{r}_{q} \\
\mathbf{r}_{v} \\
\mathbf{r}_{b a} \\
\mathbf{r}_{b g}
\end{array}\right]=\left[\begin{array}{c}
\mathbf{q}_{w b_{i}}^{*}\left(\mathbf{p}_{w b_{j}}-\mathbf{p}_{w b_{i}}-\mathbf{v}_{i}^{w} \Delta t+\frac{1}{2} \mathbf{g}^{w} \Delta t^{2}\right)-\boldsymbol{\alpha}_{b_{i} b_{j}} \\
2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} \\
\mathbf{q}_{w b_{i}}^{*}\left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)-\boldsymbol{\beta}_{b_{i} b_{j}} \\
\mathbf{b}_{j}^{a}-\mathbf{b}_{i}^{a} \\
\mathbf{b}_{j}^{g}-\mathbf{b}_{i}^{g}
\end{array}\right]
rprqrvrbarbg=qwbi∗(pwbj−pwbi−viwΔt+21gwΔt2)−αbibj2[qbibj∗⊗(qwbi∗⊗qwbj)]xyzqwbi∗(vjw−viw+gwΔt)−βbibjbja−biabjg−big
rp\mathbf{r}_{p}rp对i时刻状态的雅克比:
- 对i\mathrm{i}i时刻 pbiw\mathrm{p}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}pbiw的导数:
∂rp∂pbiw=−Rwbi \frac{\partial r_p}{\partial \mathrm{p}_{b_{i}}^{w}}=-\mathrm{R}_{\mathrm{w}}^{b_{i}} ∂pbiw∂rp=−Rwbi - 对i\mathrm{i}i时刻vbiw\mathrm{v}_{\mathrm{b_i}}^{\mathrm{w}}vbiw的导数:
∂rp∂vbiw=−RwbiΔt \frac{\partial r_p}{\partial \mathrm{v}_{b_{i}}^{w}}=-R_{w}^{b_{i}} \Delta t ∂vbiw∂rp=−RwbiΔt - 对i\mathrm{i}i时刻qbiw\mathrm{q}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}qbiw的导数:
∂rpδθbiw=∂Rwbiexp([δθbiw]×)(pbjw−pbiw−viwΔt+12 gwΔt2)∂δθbiw≈∂Rwbi(I+[δθbiw]×)(pbjw−pbiw−viwΔt+12 gwΔt2)∂δθbiw=∂−[δθbiw]×Rwbi(pbjw−pbiw−viwΔt+12 gwΔt2)∂δθbiw=∂[Rwbi(pbjw−pbiw−viwΔt+12 gwΔt2)]×δθbiw∂δθbkw=[Rwbi(pbjw−pbiw−viwΔt+12 gwΔt2)]x \begin{array}{l} \frac{\partial r_p}{\delta \theta_{b_i}^{w}}=\frac{\partial \mathrm{R}_{\mathrm{w}}^{\mathrm{b}_{\mathrm{i}}} \exp \left(\left[\delta \theta_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}\right]_{\times}\right)\left(\mathrm{p}_{\mathrm{b}_{j}}^{\mathrm{w}}-\mathrm{p}_{\mathrm{b}_{i}}^{\mathrm{w}}-\mathrm{v}_{i}^{\mathrm{w}} \Delta \mathrm{t}+\frac{1}{2} \mathrm{~g}^{\mathrm{w}} \Delta \mathrm{t}^{2}\right)}{\partial \delta \theta_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}} \\ \approx \frac{\partial \mathrm{R}_{\mathrm{w}}^{\mathrm{b}_{i}}\left(\mathrm{I}+\left[\delta \theta_{\mathrm{b}_i}^{\mathrm{w}}\right]_{\times}\right)\left(\mathrm{p}_{\mathrm{b}_j}^{\mathrm{w}}-\mathrm{p}_{\mathrm{b}_{i}}^{\mathrm{w}}-\mathrm{v}_{i}^{\mathrm{w}} \Delta \mathrm{t}+\frac{1}{2} \mathrm{~g}^{\mathrm{w}} \Delta \mathrm{t}^{2}\right)}{\partial \delta \theta_{\mathrm{b}_i}^{\mathrm{w}}} \\ =\frac{\partial-\left[\delta \theta_{\mathrm{b}_{i}}^{\mathrm{w}}\right]_{\times} \mathrm{R}_{\mathrm{w}}^{\mathrm{b}_{i}}\left(\mathrm{p}_{\mathrm{b}_j}^{\mathrm{w}}-\mathrm{p}_{\mathrm{b}_i}^{\mathrm{w}}-\mathrm{v}_i^{\mathrm{w}} \Delta \mathrm{t}+\frac{1}{2} \mathrm{~g}^{\mathrm{w}} \Delta \mathrm{t}^{2}\right)}{\partial \delta \theta_{\mathrm{b}_i}^{\mathrm{w}}} \\ =\frac{\partial\left[\mathrm{R}_{\mathrm{w}}^{\mathrm{b}_i}\left(\mathrm{p}_{\mathrm{b}_j}^{\mathrm{w}}-\mathrm{p}_{\mathrm{b}_i}^{\mathrm{w}}-\mathrm{v}_i^{\mathrm{w}} \Delta \mathrm{t}+\frac{1}{2} \mathrm{~g}^{\mathrm{w}} \Delta \mathrm{t}^{2}\right)\right]_{\times} \delta \theta_{\mathrm{b}_i}^{\mathrm{w}}}{\partial \delta \theta_{\mathrm{b}_{\mathrm{k}}}^{\mathrm{w}}} \\ =\left[\mathrm{R}_{\mathrm{w}}^{\mathrm{b}_i}\left(\mathrm{p}_{\mathrm{b}_j}^{\mathrm{w}}-\mathrm{p}_{\mathrm{b}_i}^{\mathrm{w}}-\mathrm{v}_i^{\mathrm{w}} \Delta \mathrm{t}+\frac{1}{2} \mathrm{~g}^{\mathrm{w}} \Delta \mathrm{t}^{2}\right)\right]_{\mathrm{x}} \end{array} δθbiw∂rp=∂δθbiw∂Rwbiexp([δθbiw]×)(pbjw−pbiw−viwΔt+21 gwΔt2)≈∂δθbiw∂Rwbi(I+[δθbiw]×)(pbjw−pbiw−viwΔt+21 gwΔt2)=∂δθbiw∂−[δθbiw]×Rwbi(pbjw−pbiw−viwΔt+21 gwΔt2)=∂δθbkw∂[Rwbi(pbjw−pbiw−viwΔt+21 gwΔt2)]×δθbiw=[Rwbi(pbjw−pbiw−viwΔt+21 gwΔt2)]x - 对i\mathrm{i}i时刻 ba\mathrm{b}_{\mathrm{a}}ba和 bw\mathrm{b}_{\mathrm{w}}bw的导数:
∂rp∂ba=∂rp∂αbjbi∂αbjbi∂ba=−Jbaα∂rp∂bw=∂rp∂αbjbi∂αbjbi∂bw=−Jbwα \begin{array}{l} \frac{\partial r_p}{\partial b_{a}}=\frac{\partial r_p}{\partial \alpha_{b_j}^{b_{i}}} \frac{\partial \alpha_{b_j}^{b_{i}}}{\partial b_{a}}=-J_{b_{a}}^{\alpha} \\ \frac{\partial r_p}{\partial b_{w}}=\frac{\partial r_p}{\partial \alpha_{b_j}^{b_i}} \frac{\partial \alpha_{b_j}^{b_i}}{\partial b_{w}}=-J_{b_{w}}^{\alpha} \end{array} ∂ba∂rp=∂αbjbi∂rp∂ba∂αbjbi=−Jbaα∂bw∂rp=∂αbjbi∂rp∂bw∂αbjbi=−Jbwα
rp\mathbf{r}_{p}rp对j时刻状态的雅克比:
∂rp∂pbjw=Rwbi∂rp∂vbjw=0∂rpδθbjw=0∂rp∂ba=0∂rp∂bw=0 \begin{array}{l} \frac{\partial r_p}{\partial \mathrm{p}_{b_{j}}^{w}} = \mathrm{R}_{\mathrm{w}}^{b_{i}}\\ \frac{\partial r_p}{\partial \mathrm{v}_{b_{j}}^{w}} = 0\\ \frac{\partial r_p}{\delta \theta_{b_j}^{w}} = 0\\ \frac{\partial r_p}{\partial b_{a}} = 0\\ \frac{\partial r_p}{\partial b_{w}} = 0 \end{array} ∂pbjw∂rp=Rwbi∂vbjw∂rp=0δθbjw∂rp=0∂ba∂rp=0∂bw∂rp=0
rq\mathbf{r}_{q}rq对i时刻状态的雅克比:
∂rq∂pbiw=0∂rq∂vbiw=0∂rq∂bia=0 \begin{array}{l} \frac{\partial r_q}{\partial \mathrm{p}_{b_{i}}^{w}} = 0 \\ \frac{\partial r_q}{\partial \mathrm{v}_{b_{i}}^{w}} = 0\\ \frac{\partial r_q}{\partial \mathrm{b_{i}}^{a}} = 0 \end{array} ∂pbiw∂rq=0∂vbiw∂rq=0∂bia∂rq=0
- 对i\mathrm{i}i时刻 θbiw\mathrm{\theta}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}θbiw的导数:
∂rq∂θbiw=∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz∂θbiw=∂2[qbibj∗⊗(qwbi⊗[112δθbiw])∗⊗qwbj]xyz∂θbiw=∂−2[(qbibj∗⊗(qwbi⊗[112δθbiw])∗⊗qwbj)∗]xyz∂θbiw=∂−2[qwbj∗⊗(qwbi⊗[112δθbiw])⊗qbibj]xyz∂θbiw=∂−2[qwbj∗⊗(qwbi⊗[112δθbiw])⊗qbibj]xyz∂θbiw=−2[0I]∂qwbj∗⊗(qwbi⊗[112δθbiw])⊗qbibj∂θbiw=−2[0I]∂qwbj∗⊗qwbi⊗[112δθbiw]⊗qbibj∂θbiw=−2[0I]∂L(qwbj∗⊗qwbi)R(qbibj)[112δθbiw]∂θbiw=−2[0I]L(qwbj∗⊗qwbi)R(qbibj)[012I]=−L(qwbj∗⊗qwbi)R(qbibj) \begin{align} \frac{\partial r_q}{\partial \theta ^{w}_{b_i}} & = \frac{\partial 2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} }{\partial \theta ^{w}_{b_i}} \\ & = \frac{\partial 2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix}\right)^{*} \otimes \mathbf{q}_{w b_{j}}\right]_{x y z} }{\partial \theta ^{w}_{b_i}} \\ & = \frac{\partial -2\left[\left(\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix}\right)^{*} \otimes \mathbf{q}_{w b_{j}}\right)^{{\color{Red} *} }\right]_{x y z} }{\partial \theta ^{w}_{b_i}} \\ & =\frac{\partial - 2\left[\mathbf{q}_{w b_{j}}^{*} \otimes \left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix}\right) \otimes \mathbf{q}_{b_{i} b_{j}} \right]_{x y z} }{\partial \theta ^{w}_{b_i}} \\ & =\frac{\partial - 2\left[\mathbf{q}_{w b_{j}}^{*} \otimes \left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix}\right) \otimes \mathbf{q}_{b_{i} b_{j}} \right]_{x y z} }{\partial \theta ^{w}_{b_i}} \\ & = - 2\begin{bmatrix} 0 & I \end{bmatrix}\frac{\partial \mathbf{q}_{w b_{j}}^{*} \otimes \left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix}\right) \otimes \mathbf{q}_{b_{i} b_{j}} }{\partial \theta ^{w}_{b_i}} \\ &= - 2\begin{bmatrix} 0 & I \end{bmatrix}\frac{\partial \mathbf{q}_{w b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix} \otimes \mathbf{q}_{b_{i} b_{j}} }{\partial \theta ^{w}_{b_i}} \\ & = - 2\begin{bmatrix} 0 & I \end{bmatrix}\frac{\partial \mathbf{L}\left( \mathbf{q}_{w b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} \right )\mathbf{R}\left( \mathbf{q}_{b_{i} b_{j}}\right) \begin{bmatrix} 1 \\ \frac{1}{2} \delta \theta^{w}_{b_i} \end{bmatrix} }{\partial \theta ^{w}_{b_i}} \\ & = - 2\begin{bmatrix} 0 & I \end{bmatrix}\mathbf{L}\left( \mathbf{q}_{w b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} \right )\mathbf{R}\left( \mathbf{q}_{b_{i} b_{j}}\right) \begin{bmatrix} 0 \\ \frac{1}{2}I \end{bmatrix} \\ &= -\mathbf{L}\left( \mathbf{q}_{w b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} \right )\mathbf{R}\left( \mathbf{q}_{b_{i} b_{j}}\right) \end{align} ∂θbiw∂rq=∂θbiw∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz=∂θbiw∂2[qbibj∗⊗(qwbi⊗[121δθbiw])∗⊗qwbj]xyz=∂θbiw∂−2[(qbibj∗⊗(qwbi⊗[121δθbiw])∗⊗qwbj)∗]xyz=∂θbiw∂−2[qwbj∗⊗(qwbi⊗[121δθbiw])⊗qbibj]xyz=∂θbiw∂−2[qwbj∗⊗(qwbi⊗[121δθbiw])⊗qbibj]xyz=−2[0I]∂θbiw∂qwbj∗⊗(qwbi⊗[121δθbiw])⊗qbibj=−2[0I]∂θbiw∂qwbj∗⊗qwbi⊗[121δθbiw]⊗qbibj=−2[0I]∂θbiw∂L(qwbj∗⊗qwbi)R(qbibj)[121δθbiw]=−2[0I]L(qwbj∗⊗qwbi)R(qbibj)[021I]=−L(qwbj∗⊗qwbi)R(qbibj)
- 对i\mathrm{i}i时刻 big\mathrm{b}_\mathrm{i}^\mathrm{g}big的导数:
由
αbk+1bk≈α^bk+1bk+Jbaαδbak+Jbwαδbwkβbk+1bk≈β^bk+1bk+Jbaβδbak+Jbwβδbwkγbk+1bk≈γ^bk+1bk⊗[112Jbwγδbwk] \begin{array}{l} \alpha_{b_{k+1}}^{b_{k}} \approx \hat{\alpha}_{b_{k+1}}^{b_{k}}+\mathbf{J}_{b_{a}}^{\alpha} \delta b_{a_{k}}+\mathbf{J}_{b_{w}}^{\alpha} \delta b_{w_{k}} \\ \beta_{b_{k+1}}^{b_{k}} \approx \hat{\beta}_{b_{k+1}}^{b_{k}}+\mathbf{J}_{b_{a}}^{\beta} \delta b_{a_{k}}+\mathbf{J}_{b_{w}}^{\beta} \delta b_{w_{k}} \\ \gamma_{b_{k+1}}^{b_{k}} \approx \hat{\gamma}_{b_{k+1}}^{b_{k}} \otimes\left[\begin{array}{c} 1 \\ \frac{1}{2} \mathbf{J}_{b_{w}}^{\gamma} \delta b_{w_{k}} \end{array}\right] \end{array} αbk+1bk≈α^bk+1bk+Jbaαδbak+Jbwαδbwkβbk+1bk≈β^bk+1bk+Jbaβδbak+Jbwβδbwkγbk+1bk≈γ^bk+1bk⊗[121Jbwγδbwk]
可得
∂rq∂big=∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz∂big=∂2[(qbibj⊗[112Jbigqδbig])∗⊗(qwbi∗⊗qwbj)]xyz∂big=∂−2[((qbibj⊗[112Jbigqδbig])∗⊗(qwbi∗⊗qwbj))∗]xyz∂big=∂−2[qwbj∗⊗qwbi⊗(qbibj⊗[112Jbigqδbig])]xyz∂big=−2[0I]∂qwbj∗⊗qwbi⊗(qbibj⊗[112Jbigqδbig])∂big=−2[0I]∂L(qwbj∗⊗qwbi⊗qbibj)[112Jbigqδbig]∂big=−2[0I]L(qwbj∗⊗qwbi⊗qbibj)[012Jbigq]=−L(qwbj∗⊗qwbi⊗qbibj)Jbigq
\begin{align}
\frac{\partial r_q}{\partial b ^{g}_{i}} & = \frac{\partial 2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} }{\partial b ^{g}_{i}} \\
& = \frac{\partial 2\left[\left (\mathbf{q}_{b_{i} b_{j}} \otimes {\color{Red} \begin{bmatrix}
1 \\ \frac{1}{2}J^q_ {b_i^g}\delta b_{i}^g
\end{bmatrix}}\right)^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} }{\partial b ^{g}_{i}} \\
& = \frac{\partial -2\left[\left (\left (\mathbf{q}_{b_{i} b_{j}} \otimes \begin{bmatrix}
1 \\ \frac{1}{2}J^q_ {b_i^g}\delta b_{i}^g
\end{bmatrix}\right)^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right)^{\color{Red} *} \right]_{x y z} }{\partial b ^{g}_{i}} \\
& = \frac{\partial -2\left[\mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\otimes \left (\mathbf{q}_{b_{i} b_{j}} \otimes \begin{bmatrix}
1 \\ \frac{1}{2}J^q_ {b_i^g}\delta b_{i}^g
\end{bmatrix}\right)\right]_{x y z} }{\partial b ^{g}_{i}} \\
& = -2\begin{bmatrix}
0 & I
\end{bmatrix}\frac{\partial \mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\otimes \left (\mathbf{q}_{b_{i} b_{j}} \otimes \begin{bmatrix}
1 \\ \frac{1}{2}J^q_ {b_i^g}\delta b_{i}^g
\end{bmatrix}\right)}{\partial b ^{g}_{i}} \\
& = -2\begin{bmatrix}
0 & I
\end{bmatrix}\frac{\partial \mathbf{L}\left ( \mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\otimes \mathbf{q}_{b_{i} b_{j}} \right ) \begin{bmatrix}
1 \\ \frac{1}{2}J^q_ {b_i^g}\delta b_{i}^g
\end{bmatrix}}{\partial b ^{g}_{i}} \\
& = -2\begin{bmatrix}
0 & I
\end{bmatrix}\mathbf{L}\left ( \mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\otimes \mathbf{q}_{b_{i} b_{j}} \right ) \begin{bmatrix}
0\\ \frac{1}{2}J^q_ {b_i^g}
\end{bmatrix} \\
& = -\mathbf{L}\left ( \mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\otimes \mathbf{q}_{b_{i} b_{j}} \right ) J^q_ {b_i^g}
\end{align}
∂big∂rq=∂big∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz=∂big∂2[(qbibj⊗[121Jbigqδbig])∗⊗(qwbi∗⊗qwbj)]xyz=∂big∂−2[((qbibj⊗[121Jbigqδbig])∗⊗(qwbi∗⊗qwbj))∗]xyz=∂big∂−2[qwbj∗⊗qwbi⊗(qbibj⊗[121Jbigqδbig])]xyz=−2[0I]∂big∂qwbj∗⊗qwbi⊗(qbibj⊗[121Jbigqδbig])=−2[0I]∂big∂L(qwbj∗⊗qwbi⊗qbibj)[121Jbigqδbig]=−2[0I]L(qwbj∗⊗qwbi⊗qbibj)[021Jbigq]=−L(qwbj∗⊗qwbi⊗qbibj)Jbigq
rq\mathbf{r}_{q}rq对j时刻状态的雅克比:
- 对j\mathrm{j}j时刻 θbjw\mathrm{\theta}_{\mathrm{b}_{\mathrm{j}}}^{\mathrm{w}}θbjw的导数:
∂rq∂θbjw=∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz∂θbjw=∂2[qbibj∗⊗qwbi∗⊗qwbj⊗[112δθbjw]]xyz∂θbjw=2[0I]∂qbibj∗⊗qwbi∗⊗qwbj⊗[112δθbjw]∂θbjw=2[0I]∂L(qbibj∗⊗qwbi∗⊗qwbj)[112δθbjw]∂θbjw=2[0I]L(qbibj∗⊗qwbi∗⊗qwbj)[012I]=L(qbibj∗⊗qwbi∗⊗qwbj) \begin{align} \frac{\partial r_q}{\partial \theta ^{w}_{b_j}} & = \frac{\partial 2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\left(\mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right)\right]_{x y z} }{\partial \theta ^{w}_{b_j}} \\ & = \frac{\partial 2\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} ^{*} \otimes \mathbf{q}_{w b_{j}}\otimes \begin{bmatrix} 1 \\ \frac{1}{2\delta \theta^{w}_{b_j}} \end{bmatrix}\right]_{x y z} }{\partial \theta ^{w}_{b_j}} \\ &= 2\begin{bmatrix} 0& I \end{bmatrix}\frac{\partial\mathbf{q}_{b_{i} b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} ^{*} \otimes \mathbf{q}_{w b_{j}}\otimes \begin{bmatrix} 1 \\ \frac{1}{2\delta \theta^{w}_{b_j}} \end{bmatrix} }{\partial \theta ^{w}_{b_j}} \\ &= 2\begin{bmatrix} 0& I \end{bmatrix}\frac{\partial\mathbf{L}\left ( \mathbf{q}_{b_{i} b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} ^{*} \otimes \mathbf{q}_{w b_{j}}\right) \begin{bmatrix} 1 \\ \frac{1}{2\delta \theta^{w}_{b_j}} \end{bmatrix} }{\partial \theta ^{w}_{b_j}} \\ &= 2\begin{bmatrix} 0& I \end{bmatrix}\mathbf{L}\left ( \mathbf{q}_{b_{i} b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} ^{*} \otimes \mathbf{q}_{w b_{j}}\right) \begin{bmatrix} 0 \\ \frac{1}{2} I \end{bmatrix} \\ &=\mathbf{L}\left ( \mathbf{q}_{b_{i} b_{j}}^{*} \otimes\mathbf{q}_{w b_{i}} ^{*} \otimes \mathbf{q}_{w b_{j}}\right) \\ \end{align} ∂θbjw∂rq=∂θbjw∂2[qbibj∗⊗(qwbi∗⊗qwbj)]xyz=∂θbjw∂2[qbibj∗⊗qwbi∗⊗qwbj⊗[12δθbjw1]]xyz=2[0I]∂θbjw∂qbibj∗⊗qwbi∗⊗qwbj⊗[12δθbjw1]=2[0I]∂θbjw∂L(qbibj∗⊗qwbi∗⊗qwbj)[12δθbjw1]=2[0I]L(qbibj∗⊗qwbi∗⊗qwbj)[021I]=L(qbibj∗⊗qwbi∗⊗qwbj) - 对j\mathrm{j}j时刻 pbjw\mathrm{p}_{\mathrm{b}_{\mathrm{j}}}^{\mathrm{w}}pbjw、vbjw\mathrm{v}_{\mathrm{b}_{\mathrm{j}}}^{\mathrm{w}}vbjw、bja\mathrm{b_{j}}^{a}bja 、bjg\mathrm{b_{j}}^{g}bjg的导数:
∂rq∂pbjw=0∂rq∂vbjw=0∂rq∂bja=0∂rq∂bjg=0 \begin{array}{l} \frac{\partial r_q}{\partial \mathrm{p}_{b_{j}}^{w}} = 0 \\ \frac{\partial r_q}{\partial \mathrm{v}_{b_{j}}^{w}} = 0\\ \frac{\partial r_q}{\partial \mathrm{b_{j}}^{a}} = 0 \\ \frac{\partial r_q}{\partial \mathrm{b_{j}}^{g}} = 0 \end{array} ∂pbjw∂rq=0∂vbjw∂rq=0∂bja∂rq=0∂bjg∂rq=0
rv\mathbf{r}_{v}rv对i时刻状态的雅克比:
-
对i\mathrm{i}i时刻 θbiw\mathrm{\theta}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}θbiw的导数:
∂rv∂θbiw=∂qwbi∗(vjw−viw+gwΔt)∂θbiw=∂(qwbi⊗[112δθbiw])∗(vjw−viw+gwΔt)∂θbiw=∂(I−δθbiw∧)RwbiT(vjw−viw+gwΔt)∂θbiw=∂−δθbiw∧RwbiT(vjw−viw+gwΔt)∂θbiw=(RwbiT(vjw−viw+gwΔt))∧ \begin{align} \frac{\partial r_v}{\partial \theta _{b_i}^w} & = \frac{\partial \mathbf{q}_{w b_{i}}^{*}\left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)}{\partial \theta _{b_i}^w} \\ & = \frac{\partial \left(\mathbf{q}_{w b_{i}} \otimes \begin{bmatrix} 1\\ \frac{1}{2}\delta \theta _{b_i}^w \end{bmatrix}\right)^{*}\left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)}{\partial \theta _{b_i}^w} \\ &=\frac{\partial \left ( I- {\delta \theta^w_{b_{i}}}^\wedge \right )R_{wb_i}^T \left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)}{\partial \theta _{b_i}^w} \\ &=\frac{\partial - {\delta \theta^w_{b_{i}}}^\wedge R_{wb_i}^T \left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)}{\partial \theta _{b_i}^w} \\ &= \left (R_{wb_i}^T \left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)\right )^{\wedge } \end{align} ∂θbiw∂rv=∂θbiw∂qwbi∗(vjw−viw+gwΔt)=∂θbiw∂(qwbi⊗[121δθbiw])∗(vjw−viw+gwΔt)=∂θbiw∂(I−δθbiw∧)RwbiT(vjw−viw+gwΔt)=∂θbiw∂−δθbiw∧RwbiT(vjw−viw+gwΔt)=(RwbiT(vjw−viw+gwΔt))∧ -
对i时刻vbiw\mathrm{v}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}vbiw的导数
∂rv∂vbiw=−RwbiT \frac{\partial r_v}{\partial v _{b_i}^w}=-R^{T}_{wb_i} ∂vbiw∂rv=−RwbiT -
对i时刻bia\mathrm{b_{i}}^{a}bia、big\mathrm{b_{i}}^{g}big的导数
∂rv∂ba=∂rv∂βbjbi∂βbjbi∂ba=−Jbaβ∂rv∂bg=∂rv∂βbjbi∂βbjbi∂bg=−Jbgβ \begin{array}{l} \frac{\partial r_v}{\partial b_{a}}=\frac{\partial r_v}{\partial \beta_{b_j}^{b_{i}}} \frac{\partial\beta_{b_j}^{b_{i}}}{\partial b_{a}}=-J_{b_{a}}^{\beta} \\ \frac{\partial r_v}{\partial b_{g}}=\frac{\partial r_v}{\partial \beta_{b_j}^{b_i}} \frac{\partial \beta_{b_j}^{b_i}}{\partial b_{g}}=-J_{b_{g}}^{\beta} \end{array} ∂ba∂rv=∂βbjbi∂rv∂ba∂βbjbi=−Jbaβ∂bg∂rv=∂βbjbi∂rv∂bg∂βbjbi=−Jbgβ -
对i时刻pbiw\mathrm{p}_{\mathrm{b}_{\mathrm{i}}}^{\mathrm{w}}pbiw的导数
∂rv∂pbiw=0 \frac{\partial r_v}{\partial p_{b_i}^w}=0 ∂pbiw∂rv=0
rv\mathbf{r}_{v}rv对j时刻状态的雅克比:
∂rq∂pbjw=0∂rq∂vbjw=RwbiT∂rq∂θbjw=0∂rq∂bja=0∂rq∂bjg=0 \begin{array}{l} \frac{\partial r_q}{\partial \mathrm{p}_{b_{j}}^{w}} = 0 \\ \frac{\partial r_q}{\partial \mathrm{v}_{b_{j}}^{w}} = R_{wb_i}^T\\ \frac{\partial r_q}{\partial \mathrm{\theta}_{b_{j}}^{w}} = 0\\ \frac{\partial r_q}{\partial \mathrm{b_{j}}^{a}} = 0 \\ \frac{\partial r_q}{\partial \mathrm{b_{j}}^{g}} = 0 \end{array} ∂pbjw∂rq=0∂vbjw∂rq=RwbiT∂θbjw∂rq=0∂bja∂rq=0∂bjg∂rq=0
总结
- 对i\mathrm{i}i 时刻[δpbiw,δθbiw]\left[\delta p_{b_{i}}^{w}, \delta \theta_{b_{i}}^{w}\right][δpbiw,δθbiw]求偏导
J[0]=[∂r∂pbiw∂r∂θbiw]=[−Rbiw[Rbiw(pwbj−pwbi−viwΔt+12gwΔt2)]×0−2[0I][qwbj∗⊗qwbi]L[qbibj]R[012I]0[Rbiw(vjw−viw+gwΔt)]×0000]∈R15×7 \mathbf{J}[0]=\begin{bmatrix} \frac{\partial r}{\partial \mathrm{p}_{b_{i}}^{w}} & \frac{\partial r}{\partial \mathrm{\theta }_{b_{i}}^{w}} \end{bmatrix}=\left[\begin{array}{cc} -\mathbf{R}_{b_{i} w} & {\left[\mathbf{R}_{b_{i} w}\left(\mathbf{p}_{w b_{j}}-\mathbf{p}_{w b_{i}}-\mathbf{v}_{i}^{w} \Delta t+\frac{1}{2} \mathbf{g}^{w} \Delta t^{2}\right)\right]_{\times}} \\ \mathbf{0} & -2\left[\begin{array}{cc} \mathbf{0} & \mathbf{I} \end{array}\right]\left[\mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}\right]_{L}\left[\mathbf{q}_{b_{i} b_{j}}\right]_{R}\left[\begin{array}{c} \mathbf{0} \\ \frac{1}{2} \mathbf{I} \end{array}\right] \\ \mathbf{0} & {\left[\mathbf{R}_{b_{i} w}\left(\mathbf{v}_{j}^{w}-\mathbf{v}_{i}^{w}+\mathbf{g}^{w} \Delta t\right)\right]_{\times}} \\ \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} \end{array}\right] \in \mathbb{R}^{15 \times 7} J[0]=[∂pbiw∂r∂θbiw∂r]=−Rbiw0000[Rbiw(pwbj−pwbi−viwΔt+21gwΔt2)]×−2[0I][qwbj∗⊗qwbi]L[qbibj]R[021I][Rbiw(vjw−viw+gwΔt)]×00∈R15×7 - 对i\mathrm{i}i时刻[δviw,δbia,δbig]\left[\delta v_{i}^{w}, \delta b_{i}^{a}, \delta b_{i}^{g}\right][δviw,δbia,δbig]求偏导
J[1]=[∂r∂vbiw∂r∂bia∂r∂big]=[−RbiwΔt−Jbiaα−Jbigα00−2[0I][qwbj∗⊗qwbi⊗qbibj]L[012Jbigq]−Rbiw−Jbiaβ−Jbigβ0−I000−I]∈R15×9 \mathbf{J}[1]=\begin{bmatrix} \frac{\partial r}{\partial \mathrm{v}_{b_{i}}^{w}} & \frac{\partial r}{\partial \mathrm{b_{i}}^{a}}&\frac{\partial r}{\partial \mathrm{b_{i}}^{g}} \end{bmatrix}=\left[\begin{array}{ccc} -\mathbf{R}_{b_{i} w} \Delta t & -\mathbf{J}_{b_{i}^{a}}^{\alpha} & -\mathbf{J}_{b_{i}^{g}}^{\alpha} \\ \mathbf{0} & \mathbf{0} & -2\left[\begin{array}{ll} \mathbf{0} & \mathbf{I} \end{array}\right]\left[\begin{array}{c} \mathbf{q}_{w b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}} \otimes \mathbf{q}_{b_{i} b_{j}} \end{array}\right]_{L}\left[\begin{array}{c} \mathbf{0} \\ \frac{1}{2} \mathbf{J}_{b_{i}^{g}}^{q} \end{array}\right] \\ -\mathbf{R}_{b_{i} w} & -\mathbf{J}_{b_{i}^{a}}^{\beta} & -\mathbf{J}_{b_{i}^{g}}^{\beta} \\ \mathbf{0} & -\mathbf{I} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & -\mathbf{I} \end{array}\right] \in \mathbb{R}^{15 \times 9} J[1]=[∂vbiw∂r∂bia∂r∂big∂r]=−RbiwΔt0−Rbiw00−Jbiaα0−Jbiaβ−I0−Jbigα−2[0I][qwbj∗⊗qwbi⊗qbibj]L[021Jbigq]−Jbigβ0−I∈R15×9 - 对j时刻[δpbjw,δθbjw]\left[\delta p_{b_{j}}^{w}, \delta \theta_{b_{j}}^{w}\right. ][δpbjw,δθbjw]求偏导
J[2]=[∂r∂pbjw∂r∂θbjw]=[Rbiw002[0I][qbibj∗⊗qwbi∗⊗qwbj]L[012I]000000]∈R15×7 \mathbf{J}[2]=\begin{bmatrix} \frac{\partial r}{\partial \mathrm{p}_{b_{j}}^{w}} & \frac{\partial r}{\partial \mathrm{\theta }_{b_{j}}^{w}} \end{bmatrix}=\left[\begin{array}{cc} \mathbf{R}_{b_{i} w} & \mathbf{0} \\ \mathbf{0} & 2\left[\begin{array}{ll} \mathbf{0} & \mathbf{I} \end{array}\right]\left[\mathbf{q}_{b_{i} b_{j}}^{*} \otimes \mathbf{q}_{w b_{i}}^{*} \otimes \mathbf{q}_{w b_{j}}\right]_{L}\left[\begin{array}{c} \mathbf{0} \\ \frac{1}{2} \mathbf{I} \end{array}\right] \\ \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} \end{array}\right] \in \mathbb{R}^{15 \times 7} J[2]=[∂pbjw∂r∂θbjw∂r]=Rbiw000002[0I][qbibj∗⊗qwbi∗⊗qwbj]L[021I]000∈R15×7 - 对j时刻[δvjw,δbja,δbjg]\left[\delta v_{j}^{w}, \delta b_{j}^{a}, \delta b_{j}^{g}\right][δvjw,δbja,δbjg]求偏导
J[3]=[∂r∂vbjw∂r∂bja∂r∂bjg]=[000000Rbiw000I000I]∈R15×9 \mathbf{J}[3]=\begin{bmatrix} \frac{\partial r}{\partial \mathrm{v}_{b_{j}}^{w}} & \frac{\partial r}{\partial \mathrm{b_{j}}^{a}}&\frac{\partial r}{\partial \mathrm{b_{j}}^{g}} \end{bmatrix}=\left[\begin{array}{ccc} \mathbf{0} & \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{0} \\ \mathbf{R}_{b_{i} w} & \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{I} & \mathbf{0} \\ \mathbf{0} & \mathbf{0} & \mathbf{I} \end{array}\right] \in \mathbb{R}^{15 \times 9} J[3]=[∂vbjw∂r∂bja∂r∂bjg∂r]=00Rbiw00000I00000I∈R15×9