**2.2 Passage assistance technology for the visually impaired of Primpo Co. (Isonic-Primpo)**

In order to overcome the limitation that the existing canes for the visually impaired could not detect obstacles higher than waist height, as shown in **Figure 4**,

## **Figure 3.**

*Smart cane configuration diagram of NAVIWALK model [14, 25].*

#### **Figure 4.**

*Isonic-Primpo voice recognition support for the visually impaired [15].*

Isonic-Primpo is characterized by attaching an ultrasonic sensor to support a wider detection range [15]. It can detect obstacles located within 2 m from the user and even thin and slender obstacles with a thickness of 3 cm, and it can recognize up to an angle of 25° left and right. It can inform the user of the color of obstacles with a voice and can inform the user of brightness level with a voice. User-centered voice support is possible while delivering obstacle location information with a stronger vibration as it gets closer. In particular, as an obstacle detection electronic cane, it has the great advantages in its strong vibration tactile system and voice recognition support that can overcome visual limitations.
