**4. Simulation test and user satisfaction evaluation**

For the evaluation of the system and algorithm presented in this chapter, a mobile app was produced based on the design presented in Section 3, and the user satisfaction was evaluated through a survey for the visually impaired before and after the application of the system of this chapter. For the user satisfaction survey, the waiting room of Busan City Hall Station was selected as an application target, and the nodes of the smart braille block were coded through the field survey, and route guidance information for the visually impaired to the destination could be provided through the connection of the coded nodes. **Figure 13** shows the mapping of IoT sensors and their connection status according to the smart braille block in the waiting room of Busan City Hall Station. The city hall, two ticket gates, toilets, and preferential ticketing machines, which are destinations that can be reached from ① of the station

*IoT-Based Route Guidance Technology for the Visually Impaired in Indoor Area DOI: http://dx.doi.org/10.5772/intechopen.105549*

**Figure 13.** *Mapping of IoT sensors in case Busan City hall station.*

exit gate 4, are displayed, and it can be confirmed that they are linked to each other. If a destination is selected from the location where the main facilities including the exit gate ①, which are each destination, are located, nodes are linked to the destination and route guidance is provided along the linked route.

**Figure 14** shows some part of the screen of the mobile app produced. The left first screen is the initial screen displayed when the user runs the app after arriving at the location of major facilities in the station; through voice recognition, the visually impaired people can easily select the destination they want to go to. Furthermore, it

#### **Figure 14.** *Developed mobile app windows (in Korean).*

was also produced to provide a user interface (UI) that allows users to select and set destinations through screen touch rather than voice recognition. When a destination is selected through voice recognition or screen touch, the route is set by linking the sensor nodes as shown in **Figure 13** to the destination route, and the route to the destination is sequentially guided as shown in the middle two screens in **Figure 14**. In this case, route information is sequentially provided to the visually impaired through the voice displayed in red as well as the image to be guided, and when they finally arrive at the destination, the voice guidance is terminated.

Based on the produced mobile app, a simulation test was conducted to evaluate the development system targeting 23 visually impaired people in Busan through the Busan Blind Union. Although it is necessary to evaluate through the use of the development system in actual station, due to the corona situation, evaluation was conducted through a satisfaction survey through a simulation test. In the simulation test, an environment was established where the visually impaired could experience the voice route guidance system through a mobile app rather than the actual Busan City Hall station site. In other words, node information of the sensors installed in the actual Busan station was built in the actual Busan City Hall station server, and when the user selects a destination, the sensor node according to the route to the destination is linked as in reality. However, for location confirmation according to the user's movement, the movement was simulated in the app in consideration of the average movement speed of the visually impaired, and the link with the server was constructed so that route information could be provided according to the node link set identical to the actual station.

The design of the questionnaire is important in the user satisfaction survey according to the use of the development system. In this chapter, the basic survey items were applied mutatis mutandis by reviewing the "2017 Transportation Convenience Survey Study" conducted annually by the Ministry of Land, Infrastructure and Transport for the system use satisfaction survey for the test subjects. In order to understand the user satisfaction and the effect of the system on route movement, the NASA-TLX survey items were reflected as items for the satisfaction survey through the review of experts in related fields [4, 6, 23]. **Figure 15(a)** shows a photograph of the user satisfaction survey conducted by the Busan Blind Union for the 23 visually
