[AMR] Notes on tasks, improved layouts

This commit is contained in:
2026-08-01 15:15:02 +02:00
parent 76b6334433
commit 1f2ca7f5ab
7 changed files with 25 additions and 9 deletions
@@ -10,7 +10,8 @@ $ \begin{bmatrix}
}
Workspace $W$: $\theta_1, \theta_2 \in [-\pi, \pi]$.
Similar for $n$R sys (more angles, more lengths).
For 2D move in 3D space, last dim is sum of angles (or equiv). \bi{Jacobian}: see \ref{sec:ms-lin}
For 2D move in 3D space, last dim is sum of angles (or equiv).
The Jacobian of this $nD$ position is typically computed ($nD$ pos is a vec).
\bi{Jacobian}: see \ref{sec:ms-lin}.
\shortdefinition[Singularity] Loss of deg of Freed. $\det(\mat{J}(\vec{\theta})) = 0$
% TODO: Determinant computation
\shortdefinition[Singularity] Loss of deg of Freedom $\det(\mat{J}(\vec{\theta})) = 0$
@@ -2,7 +2,7 @@
\begin{wrapfigure}[10]{r}{0.35\columnwidth}
\includegraphics[width=0.35\columnwidth]{assets/inverse-kinematics.png}
\end{wrapfigure}
\bi{Option}: Solve Forward Kinematics for angles.\\
\bi{Option}: Solve FK for angles.\\
\bi{Better}: Law of cosine with polar coordinates. Compute angle using cosine rule,
$\theta_1 = \varphi \pm \alpha$, $\theta_2 = \pm(\pi - \beta)$
(Positive for {\color{ForestGreen} Elbow Down}, Neg. for {\color{red} Elbow Up})
@@ -10,5 +10,5 @@ $\theta_1 = \varphi \pm \alpha$, $\theta_2 = \pm(\pi - \beta)$
\bi{Extension to 6R}:
1. Waist: spherical coords (2 sol.)\\
2. 2 sols from 2R for shoulder + elbow\\
3. Solve for wrist joints (no influence on pos)
3. Solve for wrist joints (no infl. on pos)
@@ -9,3 +9,11 @@
${_B} \vec{v}_{CoM}$ vel. of CoM, ${_B}\omega$ rot. speed; both w.r.t. inert. frame
{\scriptsize Legged robots don't need to maintain stability!}
To determine dynamics:
\bi{(1)} Define control inputs (e.g. wheel speeds),
\bi{(2)} Assumptions / Simplifications about state \& inputs
\bi{(3)} List forces, torques, etc needed,
\bi{(4)} Express as func of states / inp
\bi{(5)} Reduce to the CoM
\bi{(6)} Plug into Newton-Euler eq combined with rigid body kinematics
@@ -19,6 +19,7 @@ To compute $\vec{c}$ in $\vec{c} \cdot {_B}\vec{v}_{WB} = \omega$
$c_i = [\sin(\alpha + \beta) \div r, -\cos(\alpha + \beta) \div r, -\cos(\beta) \cdot l \div r]$
\newpage
\bi{Maneuverability}
\begin{itemize}
\item Deg. of Mobility: $\delta_m = 3 - $\#constrained directions
@@ -26,7 +27,6 @@ $c_i = [\sin(\alpha + \beta) \div r, -\cos(\alpha + \beta) \div r, -\cos(\beta)
\item Deg. of Maneuverability: $\delta_M = \delta_m + \delta_s$
\end{itemize}
\newpage
\shade{ForestGreen}{Wheel Configurations}
\includegraphics[width=1\columnwidth]{assets/wheel-config.png}
@@ -64,3 +64,10 @@ $\vec{b}_s = {\scriptsize \begin{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 $i \in \{s, t\}$, respectively
\textbf{Swedish Wheels}: Have 3 DoF, typ. (3 pcs) equally spaced on circle.
Typ. Param. each: $\alpha, \beta, \gamma$ ($z$, $x$, $y$ axes, oriented along $x$, $z$ up)
\textbf{Wheel rot speed from movement} Typ. comp: $J \cdot \mat{R}(\theta) \cdot \vec{x} = \dot{\varphi}$,
with $\mat{R}(\theta) \cdot \vec{x}$ transform from base frame to robot frame.
% TODO: What's the second Jacobian from?? (See 2017 exam, question B.4)