Development of the Walk Navigation System for Blind People by Using 3D Sound User Interface - Constructing a Testbed

摘要

In Japan, the chance of going out for blind people is increasing. This progresses the study of walk navigation system by using the speech language for blind people. However, it seems to be difficult for the blind people to understand the indicated direction and the surrounding geographical spatial information. Then, for example, the blind people cannot trace correct route. Eventually, there is possibility that the blind people lose one's way. To solve these problems, the authors developed walk navigation system by using the 3D sound user interface. And the authors constructed the testbed of the walk navigation system by using the 3D sound user interface. 3D sound user interface uses 3D sound's characteristic that 3D sound is able to display a sound from all directions. Workings of the 3D sound user interface are (1) Displaying 3D sound image coming from a direction that the user should direct to, (2) Displaying 3D sound images coming from the position of the indoor equipment and the barrier for the user. The user can understand surrounding geographical space information by using the 3D sound user interface that the user can reach the destination Illustration of the walk navigation system by using 3D sound user interface is as follows. First, user's actual location was measured by the RFID system and the gyro sensor. The RFID system and the gyro sensor were assembled at the top of the cane. The coordinate data of user's actual location was calculated from cane's location and attitude. Secondly, navigational directional information was derived from user's actual location and the map information. The map information was stored in the memory of the control computer. Thirdly, 3D sound was generated based on navigational directional information. Lastly, it was displayed to the user via the stereo headphone And the usability evaluation experiment of walk navigation system by using the 3D sound user interface was performed. The purpose of this experiment is measuring usability of developed walk navigation system. Therefore, the usability of development navigation system to conventional navigation system was compared. This conventional navigation system was walk navigation system by using the speech language. The subjects were blind peoples and sighted peoples. Sighted peoples were reduced to pseudo blind people by loaded the eye mask. The method was tracing the navigated root. The experimental measurements are route tracing accuracy, achievement rate, achievement time, walking distance, mental workload(NASA-TLX)and evaluation grid method. As a result of achievement time and walking distance, development navigation system was lower than conventional navigation system. And, as a result of mental workload and evaluation grid method, development navigation system was much higher in terms of quality of usability than conventional navigation system. As a result of these experiments, it was suggested that the blind people could walk smoothly and understudied surrounding geographical space information by using the 3D sound user interface.