mirror of
https://github.com/janishutz/eth-summaries.git
synced 2026-07-27 21:29:09 +02:00
[AMR] Improve kinematics summary
This commit is contained in:
@@ -9,7 +9,7 @@
|
||||
\begin{itemize}
|
||||
\item \textit{Driving straight} all $\vec{v}$ equal
|
||||
\item \textit{Turning} Wheel axis must intersect the \bi{Instant Centre of Rotation} (ICR),
|
||||
speeds: $v_i \div R_i = \Omega$ ($R_i$ dist. wheel-ICR, $\Omega$, vehicle body rotation rate)
|
||||
speeds: $v_i \div R_i = \Omega$ ($R_i$ = dist. wheel-ICR; $\Omega$: vehicle body rotation rate)
|
||||
\end{itemize}
|
||||
|
||||
\bi{Maneuverability}
|
||||
@@ -19,7 +19,8 @@
|
||||
\item Deg. of Maneuverability: $\delta_M = \delta_m + \delta_s$
|
||||
\end{itemize}
|
||||
|
||||
\bi{Wheel Configurations}
|
||||
\newpage
|
||||
\shade{ForestGreen}{Wheel Configurations}
|
||||
|
||||
\includegraphics[width=1\columnwidth]{assets/wheel-config.png}
|
||||
|
||||
@@ -32,27 +33,27 @@
|
||||
\end{tabular}
|
||||
\end{scriptsize}
|
||||
|
||||
\bi{Differential Drive Kinematics}
|
||||
\shortdefinition[Differential Drive Kinematics]
|
||||
|
||||
\bi{State vec} $\vec{x} = [x_1, x_2, \theta]^\top$,
|
||||
\bi{Inputs} $\vec{u} = [\omega_l, \omega_r]^\top$, $r_r$ radius of right wheel, $w$ width of robot
|
||||
\bi{Inputs} $\vec{u} = [\omega_l, \omega_r]^\top$, radius of right (left) wheel $r_r$ ($r_l$), $w$ width of robot
|
||||
|
||||
\bi{Gen. eq. of Motion} $\dot{x}_1 = v\cos(\theta)$, $\dot{x}_2 = v\sin(\theta)$, $\dot{\theta} = \Omega$,
|
||||
with $v = 0.5\cdot(\omega_l r_l + \omega_r + r_r)$, $\Omega = \frac{\omega_r r_r - \omega_l r_l}{w}$
|
||||
|
||||
% TODO: Consider adding wheel constraints (planar) here as well (from W05 slides)
|
||||
\textit{Straight}: $v = \omega_l r_l = \omega_r r_r$, $\Omega = 0$, $D = v\Delta t$.\\
|
||||
$\vec{b}_s = \begin{bmatrix}
|
||||
$\vec{b}_s = {\scriptsize \begin{bmatrix}
|
||||
D \cos(\theta) \\
|
||||
D \sin(\theta) \\
|
||||
0
|
||||
\end{bmatrix}$
|
||||
$\vec{b}_t = \begin{bmatrix}
|
||||
R(\sin(\Delta \theta + \theta) - \sin(\theta))\\
|
||||
-R(\cos(\Delta \theta + \theta) - \cos(\theta))\\
|
||||
\Delta \theta
|
||||
\end{bmatrix}$
|
||||
\end{bmatrix}}
|
||||
\quad \vec{b}_t = {\scriptsize \begin{bmatrix}
|
||||
R(\sin(\Delta \theta + \theta) - \sin(\theta)) \\
|
||||
-R(\cos(\Delta \theta + \theta) - \cos(\theta)) \\
|
||||
\Delta \theta
|
||||
\end{bmatrix}}$
|
||||
|
||||
\textit{Turning}: $\Omega = (\omega_l r_l) / R_l\! =\! (\omega_r r_r) / R_r$, $R\! =\! v / \Omega$, $\Delta \theta\! =\! \Omega \Delta t$
|
||||
|
||||
\textbf{Discretized}: $\vec{x}_k = \vec{x}_{k - 1} b_i$ with $i \in \{s, t\}$. ($\int \ldots \dx \Delta t$)
|
||||
\textbf{Discretized}: $\vec{x}_k = \vec{x}_{k - 1} b_i$ with $i \in \{s, t\}$, respectively
|
||||
|
||||
Reference in New Issue
Block a user