抄録
Introduction
We developed the turn-by-turn voice navigation system for blind people with high accuracy and using their smartphone. Many navigation tools have been proposed so that visually impaired people can walk independently in unfamiliar places, but they did not have sufficient accuracy and required specialized devices. We verified the effectiveness of our voice navigation system in the environment with few physical clues
Method
We conducted 2 types of test: A) walking skill test and B) walking test using the navigation, with 10 blind and low vision participants.
A) Walking skill test: we measured their walking skill such as distance sense, direction sense, walking speed and veering of straight line walking.
B) Walking test using the navigation: we measured their walking path, walking distance and duration time in 2 areas with few landmarks (Piloti and Lobby in Fig. 2).
Result
The test results are as follows:
1) The more error they had in direction sense test, the more error they had in straight line walking test (Fig. 7). It is presumed that the relation between veering and direction sense error. The more error they had in straight line walking test, the longer distance they walked in Piloti (Fig. 11). Most of the low vision participants got to the entrance directly because they found the doormat in front of the entrance. Meanwhile, some participants who tend to veer off the route, walked meanderingly although the system tried to correct their position. This result suggests the voice navigation is hard to correct their veering.
2) When the turning point was deviated from the route, low vision participants corrected their position, confirming visually. Fig. 13 shows the low vision participants stopped walking in a short time to look for the stairs when they turned. Meanwhile, most of the blind participants corrected their position, using cane technique, but some participants didn't because turning point was too deviated to cane reach. Therefore, we consider that localization error has to be within about 1 meter that one's cane reaches.
Discussion
All participants succeeded in walking in the environment with few landmarks by using the voice navigation system. However, some participants missed turning or walked meanderingly because the system didn't correct their wrong positon or direction perfectly. It is assumed that we should improve not only localization accuracy but also usability by personalization based on user's walking skill.
