# Establishment and Application of Crowd-Sensing-Based System for Bridge Structural Crack Detection
## 3 Development of the Crowd Sensing Crack Collection System
### Development of Cloud Management Platform
#### 3.2.2 Interface Design  
For the convenience of users, this management platform realizes remote access through web login. Users can access it through various mainstream browsers such as the IE, the 360 browser, and the Google Chrome. The main login interface is shown in Figure 3. The interface of this cloud management system adopts account and password login. Initially, a set of account and password is set up for this system.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Overall** & **Sub-Category** & **Version** \\ \hline \multirow{3}{*}{Hardware} & Memory & 2 G \\  & Hard Drive & 40 G \\  & Bandwidth & 1 M/s \\ \cline{1-1}  & Operating system & Linux cent Os 7 \\ \cline{1-1}  & Database & MySQL 5.7 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Server hardware and software configuration.  
As shown in Figure 4 above, after logging in, the user enters the main interface of the management platform. The main interface contains three modules: account management module, record management module, and record query module. In the account management module, the number of accounts, names, phone numbers, creation time, account numbers, and passwords can be determined. The operations that can be performed on the accounts include editing, deleting, and adding. The interface for adding a new user is shown in Figure 5 below.  
The new user module can be used to increase the number of users and enhance the ability of crack detection. Privacy protection is an important part of crowd sensing systems, which can encourage participants to register and participate in sensing tasks. In order to protect the privacy of the participants, the cloud management platform only requires an account and a password to log in, and the user's name and phone number are optional, which also preserves the incentive mechanisms for future task rewards and other research purposes.  
Figure 4: Cloud management platform main interface.  
Figure 3: Cloud management platform login page.  
As shown in Figure 6, the record management interface can display the total number of images, the reporters and their respective reporting times for each image. The GPS-recorded latitude and longitude coordinates in the crack image information can reflect the location of the crack on the map. The pitch angle, heading angle, and roll angle recorded by the gyroscope can record the posture of the phone when taking pictures, thus assisting in inferring the location of the crack. The crack thumbnails allow users to have a visual understanding of the crack status. The buttons on the rightmost column of the interface can allow users to download or delete a single image or read text explanations of the crack through the details option. For convenience, the upper right corner of the record interface sets a batch processing button, where users can choose to download multiple images or download location information and text explanations in bulk, or download all at once. The crack images are downloaded in JPEG format, while other information is downloaded in Excel format, making it easy to handle through third-party software such as Matlab 9.11. Clicking the details button takes the user to the text description box, shown in Figure 7.  
Due to the complex and varied on-site situations, in addition to collecting crack images, and GPS coordinates, the system also retains the function of adding text remarks, as shown in Figure 7. Thus, participants can briefly describe the on-site situation and assist in determining the state of the bridge components or cracks.  
As shown in Figure 8, in order to visually display the crack images recorded by pedestrians, the cloud-based management platform set up a recording inquiry module. This module can provide a search function based on the photographing time and directly  
Figure 5: Adding user interface.  
Figure 6: Record management interface.