抄録
In an aging society, electric wheelchairs have become indispensable assistive devices for older adults with physical limitations, helping them maintain and improve their quality of life by enabling activities such as shopping, visiting hospitals, and participating in the local community. This study presents an intuitive human-machine interface (HMI) for situation awareness by vibration stimulation using tactile apparent motion for handle-type electric wheelchairs. The HMI has a total of eight vibration devices attached to the handle of the electric wheelchair, two at the front, two at the rear, and two on each side. Experiments were conducted at an intersection with vehicles approaching from four directions (left, right, front, and rear), and the correct response rates and response times were compared across three conditions: tactile apparent movement, normal vibration, and no vibration. Results showed that the correct response rate for tactile apparent motion in the left-right scenarios were as high as or higher than that in the no vibration condition, in which the surrounding situation was perceived visually. Similarly, response times for the tactile apparent motion condition in the left-right scenarios were the fastest compared to the normal vibration and no vibration conditions. Additionally, the result of a five-point subjective evaluation regarding sense of security granted by tactile apparent motion and normal vibration showed a significantly higher score for tactile apparent motion. These findings suggest that tactile apparent motion is particularly effective for alerting users of the presence of vehicles approaching from the left and right.
