Update second cycle section

content/appendix_specifications.tex

@@ -16,7 +16,7 @@
             \item When a wipe-signal is send to the Writer, the Writer shall wipe the board clean.
             \item The Writer shall not damage itself.
             \item While writing, the SCARA shall have a writing speed of at least 1.5 characters per second.
-            \item When the Carriage/base of the SCARA is at a static position, the SCARA shall be able to write at least three characters at that position.
+            \item When the Carriage/base of the SCARA is at a static position, the SCARA shall be able to write at least three characters at that position. \label{threecharspec}
             \item When the SCARA finished writing at their current position, the Carriage shall move the SCARA to it's next position where it can write the subsequent characters.
             \item When the SCARA has to be moved to a new position, the Carriage shall perform this movement within one second.
             \item When the system changes from writing to wiping or vice-versa, the SCARA and End-effector should change the tool within ten seconds.

content/case_experiment_scara.tex

@@ -43,23 +43,30 @@
         The following steps is to increase the detail of the model.
         This is done according to the steps in the previous section.
 
-        \subsubsection{Basics implementation}
+        \subsubsection{Basic Kinematics Model}
             \begin{marginfigure}
                     \centering
                     \includegraphics[width=0.9\linewidth]{graphics/scara_arm_kinematics.pdf}
-                    \caption{Basic kinematics of the SCARA}
+                    \caption{Basic kinematics of the SCARA. The arm consists of two linkages $a$ and $b$; two joints $\alpha$ and $\beta$; and a point mass $m$ which represents the end-effector/tool.}
                     \label{fig:scaraarm}
             \end{marginfigure}
-            The first four detail steps are just creating the basics dynamics of the SCARA as shown in \autoref{fig:scaraarm}
-            It start with the kinematics model that is used to test the forward and inverse kinematics of the design.
-            It gave a general idea of angles and arm lengths that are required in the design.
-            The second detail iteration adds the basic physics of the model.
-            This model was in the form of a double pendulum, with to powered joints.
-            The ideal motors in the joints made it that it could move with almost infinite speed.
-            To get a better idea of the forces in the model, the ideal motors are replaced with a better motor model.
-            As the system did not operate with infinite gain anymore it the path planning was updated as well.
-            A simple PID-controller was implemented to make the SCARA follow a rectangular path.
+            The development starts with a basic model model as shown in \autoref{fig:scaraarm}.
+            It consists of the forward and inverse kinematics of the design.
+            With this kinematics model it was easy to find a good configuration of the SCARA.
+            I tested if the SCARA could reach the required operating area, to be able to satisfy specification \ref{threecharspec}.
+            The operating area is not a couple of centimeters away from the base of the SCARA.
+            This is to avoid the singularity point that lies at the base of the SCARA.
+            Resulting in longer arms than strictly necessary but this reduces the operating angles of the joints allowing for simpler construction.
             
+            At this point, there are already multiple design decisions made about the position of the operating area and the arm lengths.
+            The second detail iteration adds the basic physics of the model.
+            This model was in the form of a double pendulum, with two attenuated joints.
+            The ideal motors in the joints made gave the SCARA almost unlimited acceleration.
+            As the one of the goals is to get an indication on what the required torque for these joints is, the ideal motors are replaced with basic DC-motors.
+            Implementing a simple PID-controller allowed the SCARA to follow the rectangular path as described in system test \ref{test1}.
+            Based the simulation, it was possible to determine minimum specifications of the motors.
+            The motors must be able to deliver at least \SI{0.2}{\newton\meter} of torque and reach an angular velocity of at least \SI{12}{\radian\per\second}.
+
             \begin{marginfigure}
                 \centering
                 \includegraphics[width=0.9\linewidth]{graphics/scara_20sim_model.png}
@@ -96,20 +103,22 @@
             The actuation of the arm is done with stepper motors.
             The advantage of stepper motors over simple DC-motors is that they hold a specific position.
             There is no extra feedback loop required to compensate for external forces.
-            However, they are heavier and more expensive.
-            But the extra mass is probably beneficial as adds momentum to the base.
-            Reducing the counter movement of the base when the arm is actuated.
+            They are heavier and more expensive as well.
+            The additional mass is probably beneficial as adds momentum to the base, reducing the counter movement of the base when the arm is actuated.
+            The extra costs are easily compensated as it save development time due to the simplified control law.
 
         \subsubsection{Implementing details}
             The first step was to replace the DC-motor with a stepper motor model.
             This based on a model by \textcite{karadeniz_modelling_2018}.
-            The controller is updated as well, to accommodate for the behavior of the steppers,
-
+            The controller is updated as well, to accommodate for the behavior of the steppers.
             The next step is to implement a dynamic model of the configuration (4) as shown in \autoref{fig:scaradesign}.
             The dynamics of the SCARA are based on a serial link structure \autocite{dresscher_modeling_2010}.
 
+        \subsubsection{Evaluation}
+
+
 
-        \subsubsection{3D Modeling}
+        \subsection{Prototype Construction}
             With a full dynamics model in 20-sim, the next step was to design the system in OpenSCAD.
             Although 20-sim has a 3D editor, it is significantly easier to build components with OpenSCAD.
             Furthermore, for prototyping the OpenSCAD objects can be exported for 3D printing.