# An Outdoor Navigation System for Blind Pedestrians Using GPS and Tactile-Foot Feedback
## 5 Conclusions  
Ubiquitous and wearable computing have ignited a new type of human-computer interaction with palpable applications in e-commerce, consumer electronics, business, education, and healthcare, among others. Assistive technology can benefit from these ubiquitous computing resources to improve the quality of life of people in need.  
In this context, this paper has presented the design, implementation, and experimental evaluation of a novel navigation assistive device for blind pedestrians based on GPS and tactile feedback.  
The device is intended to be used as a localization and guidance system complementary to the primary aids. Its approach relies on the haptic feedback provided by the white cane and the guide dog for detecting obstacles along a route.  
For user localization in an outdoor environment, the approach exploits the GPS coordinates provided by a smartphone. Guidance to a destination is achieved by dedicated navigation software that processes the GPS data and computes the optimal route of travel. Directions to a destination are conveyed to the user via an on-shoe tactile display. The aim of this system is to enhance outdoor navigation of visually impaired and blind people with a truly wearable, inconspicuous, reliable, and low-cost device.  
The prototype was evaluated in two stages. The first one verified the interface's ability to transmit tactile information to the user, and the user's comprehension level to this feedback. The results showed very high recognition rates, which suggests that the information displayed is intuitive and fast to understand. The second stage evaluated both the system and subjects' performances in real outdoor urban environments. The results showed that the system is capable of guiding users from a starting point to a destination by providing the pertinent directional instructions.  
Figure 7: An eventual situation involving GPS resolution.  
The prototype reported in this paper was recently featured by the BBC Horizons Series. Similar navigation experiments and blind users' testimonials can be seen in this documentary program [48].  
Future work will focus on the implementation of an Android application that fully runs in the smartphone, integrating the GIS and the route planner, and that generates the instructions for the tactile display. Figure 8 shows the proposed architecture. Note that a high-sensitivity GPS external chipset receiver will be used to increase the smartphone's position accuracy to the one-meter or sub-meter level (enhancement technologies to the GPS, such as differential GPS and satellite-based augmentation system (SBAS) will be evaluated as well). The RF module will be replaced by a Bluetooth one so that the smartphone can set directly the actuators in the tactile display. An embedded system is expected to replace the microcontroller. The cloud server and the remote station will no longer be essential modules of the system. However, they are expected to continue operating as they could be useful for the user's relatives or caretakers. Remote monitoring undoubtedly increases the user's safety and his/her family's peace of mind.  
**Author Contributions:** [PERSON] and [PERSON] conceived the system and designed the experiments. [PERSON] contributed to the tests with normally sighted and blind subjects. [PERSON] analyzed the data and advised on all aspects related to the GPS. [PERSON] and [PERSON] validated the experimental results and reviewed the paper. [PERSON] wrote the paper.  
**Conflicts of Interest:** The authors declare no conflict of interest.