| @@ -1,34 +1,11 @@ | |||||
| To ensure that the design method resulted in a functional system, a prototype will be build from the current state of the design. | To ensure that the design method resulted in a functional system, a prototype will be build from the current state of the design. | ||||
| Although the development only implemented a very small portion of the full design, I determined that a prototype is more valuable than repeating the development cycle for the next feature. | |||||
| Although the development resulted in only a partial design, I determined that a prototype is more valuable than repeating the development cycle for the next feature. | |||||
| For the construction of the prototype \ac{ots}-parts are used as much as possible and the mechanical linkages of the SCARA will be printed. | For the construction of the prototype \ac{ots}-parts are used as much as possible and the mechanical linkages of the SCARA will be printed. | ||||
| To write characters on a whiteboard, drivers and controlloop have to be implemented in software. | |||||
| To write characters on a whiteboard; drivers and controlloop are implemented in software. | |||||
| \subsection{Construction} | |||||
| The construction of the SCARA consists of a 3D printed mechanical structure that is actuated with stepper motors. | |||||
| The type of stepper motor was already chosen during the development of the SCARA. | |||||
| For the mechanical part I used OpenSCAD as CAD software, based on prior experience with the software. | |||||
| As the inverse kinematics were already determined in basic model of the SCARA they could be easily parsed to the CAD software. | |||||
| This allowed me to check for clearance between the mechanical parts, while repeating \autoref{test1}. | |||||
| The test revealed that there was collision between some parts. | |||||
| These collisions were resolved by adding a indentation and moving linkage and are shown in \autoref{fig:scad_clearance} | |||||
| The configuration with the stepper motors, servo and marker is shown in \autoref{fig:scad_carriage}. | |||||
| \begin{figure} | |||||
| \centering | |||||
| \includegraphics[width=0.8\linewidth]{graphics/scad_scara_circles.png} | |||||
| \caption{CAD of the SCARA configuration, with the end-effector orientated in the lower left corner of the operating area. | |||||
| The configuration has been adapted at the two circled points, to resolve collisions in this orientation. | |||||
| An indentation was made to ensure that the arm could make the required corner. | |||||
| Furthermore, the bottom linkage has been moved from above to below the actuated joints, as this linkage would otherwise collide with the end-effector.} | |||||
| \label{fig:scad_clearance} | |||||
| \end{figure} | |||||
| \subsection{Mechanical Construction} | |||||
| \begin{figure} | |||||
| \centering | |||||
| \includegraphics[width=0.8\linewidth]{graphics/scad_carriage.png} | |||||
| \caption{Rendered 3D model of the SCARA, including steppers, marker and servo.} | |||||
| \label{fig:scad_carriage} | |||||
| \end{figure} | |||||
| \subsection{Implementing Behavior} | \subsection{Implementing Behavior} | ||||
| Now with a physical SCARA, the last step is to implement the behavior. | Now with a physical SCARA, the last step is to implement the behavior. | ||||