# Optimizing Automated Detection of Cross-Recessed Screws in Laptops Using a Neural Network
## 2 Materials and Methods
### Screw Characteristic Analysis Methodology  
To gain deeper insights into the data regarding the detection and misidentification of individual screws, it is essential to identify potential trends among screws with varying detection rates. In pursuit of this goal, a comprehensive analysis was conducted using all 115 screws sourced from the seven different laptops. Each screw was examined to gather data on specific attributes. These attributes were categorized into four primary categories:  
1. Depth: Screws were classified as either deep or surface screws.
2. Location: The location of each screw was categorized as either belonging to the corner, exterior, or interior of the laptops.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Categories** & **Abbreviations** \\ \hline Velocity & 4 choices ( 5, 10, 15, 20 mm/s) & V5, V10, V15, V20 \\ Number of scans & 2 choices (15, 25 scans) & S15, S25 \\ Lighting & 2 choices (with light, no light) & wl, nl \\ Neural network size & 2 choices (YOLOv5-small, YOLOv5-Extra large) & S, XL \\ \hline \hline \end{tabular}
\end{table}
Table 2: Testing parameters and their corresponding testing abbreviations used throughout the study.  
Figure 4: The coordinate system of different subsystems used for trial testing. These are shown when the robot is at its home position. The spacer and offsets allow for the camera to cover the entire laptop.  
3. Color difference: The extent of color contrast between the laptop case and the screw head was assessed and grouped into categories of large, medium, or small color differences.
4. Taper presence: An evaluation was made to determine whether each screw hole exhibited a taper or not.  
In the depth category, screws were categorized based on whether they were recessed more than 0.10 inches (2.5 mm) from the laptop cover's surface. Additionally, screws were designated as \"exterior screws\" if they were positioned within 0.785 in (approx 20 mm) from the laptop's side. Within the exterior screws category, a specific subset was identified as \"corner screws\", referring to screws situated between two sides of the laptop near the edges. The presence of a taper on a screw was noted when the laptop's surface exhibited an uneven depth around it. The screws were also subject to an evaluation of their color, which included the options of silver, black, or light black. Additionally, the laptops themselves were examined for their color, which could fall into categories blue, black, or silver. These combinations were then organized into three distinct color difference categories:  
1. Large color difference: This category included instances in which black screws were paired with a silver laptop or silver screws were matched with a black laptop.
2. Medium color difference: This category encompassed situations where light black screws were paired with a black laptop or light black screws were matched with a blue laptop.
3. No color difference: This category involved cases in which black screws were matched with a black laptop or silver screws were paired with a silver laptop.