# WARM: Wearable AR and Tablet-Based Assistant Systems for Bus Maintenance
## 3 Solution Approach  
In this work, the use of wearable devices (tablet and AR device (e.g., smart headset)) is proposed. The devices do not need to be worn during the whole operation but just when required, to support the operator to complete the checklist and collect relevant multimedia data of the extraordinary facts of the activity.  
The maintenance system currently deployed in DBUS is the system GIM (Gestion Integral del Mantenimiento, Integral Maintenance Management in English), which is a Computerized maintenance management system (CMMS) developed and commercialized by the company TCMAN. Recently, TCMAN has introduced the software GIM Android App to ease the collection of maintenance data by nomadic users. This application could benefit from some of the innovations pursued by WARM, as it lacks a friendly and efficient graphic user interface (GUI) well adapted to mechanic's needs.  
Figure 1 shows a schematic of the WARM system. Once the maintenance worker receives the work order sheet from the maintenance system (back office) using Web Services, the wearable device of the WARM system connects to the bus on-board computer through the WiFi network on-board. Using this connection, the wearable device identifies the bus and reads the relevant data for the maintenance task. This connection uses a proprietary interface. Additionally, to complete the data read from the bus, a direct connection to the CAN is done. At this point, the wearable device starts guiding the work to be completed, accordingly to the work order sheet and collects all relevant information. This guidance is adapted to the \"work style\" and preferences of each maintenance worker participating in the study. The worker will use the wearable device for different purposes:  
* For dictating \"done/undone\" at the corresponding entries of the checklist form.
* For dictating annotations concerning the work done.
* For dictating the list of spares needed.
* For taking photographs and recording audio or video clips concerning the particularities of the reparation.  
Once the work is finished and the report complete, this document is sent to the back office. All communications are compliant with the standard EN13149 via WiFi.  
WARM system has been developed upon the application program interface (API) of the GIM system. Data collected with the WARM system are naturally uploaded and integrated in the DBUS maintenance servers running GIM. Besides, GIM API implements a communication layer to exchange information with GIM servers by means of Web Services. This layer has been adapted to comply with the standard EN13149. Finally, a new development was necessary to connect GIM Android APP with the bus (i.e., the CAN/FMS interface) using again the standard EN13149.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Name**} & **Asset** & **Mobile** & **Voice** & **Vehicle** & **Augmented** \\  & **Management** & **Devices** & **Recognition** & **Identification** & **Reality** \\ \hline IBM & Yes & Yes & No & Yes & No \\ Sisteplant & Yes & Yes & No & No & No \\ Idasa & Yes & Yes & No & No & No \\ Infor & Yes & Yes & No & No & No \\ Primavera & Yes & Yes & No & No & No \\ WARM & Yes & Yes & Yes & Yes & Yes \\ \hline \hline \end{tabular}
\end{table}
Table 1: Feature comparison among different maintenance management software.