Since the information given with tactile sense hardly disturbs people's activities, it is suited for daily use in mobile environment. However, many of existing systems don't transmit multiple information with tactile sense. Most of them send only simple signals, such as vibration of cellular phones. ActiveBelt is a novel belt-type wearable tactile display that can transmit multiple directional information. We have developed prototype systems and some applications, evaluated the system performance and usability, and confirmed the possibility of practical use.

The main concepts of ActiveBelt are as follows:

1. Tactile display that enables users to intuitively obtain directional information
2. Belt-type wearable device optimized for mobile use
3. Various applications especially for location-aware information services.

The first concept means that ActiveBelt can enable users to intuitively obtain directional information in the real world only by activating vibrators, since it is worn around use's torso. Since a user can easily match tactile information and direction in the real world, ActiveBelt can transmit effective information with tactile sense.
The second concept means that ActiveBelt doesn't increase a user's load on wearing, since it attaches vibrators in a usual belt worn by many people in daily life.
The third concept means that ActiveBelt can be used for various applications especially for location-aware information services like human navigation systems.

We developed a prototype system of ActiveBelt based on the above concepts. The prototype system consists of four factors: (1)ActiveBelt hardware, (2)a GPS, (3)a directional sensor, and (4) a microcomputer (Fig. 3). Fig. 4 shows the system architecture of ActiveBelt.
We attached eight vibrators (FM23A by TPC) and LEDs 3 in the belt. The diameter of FM23A is about 18 mm, and the thickness is about 3 mm. We attached four vibrators in center of abdomen, in center of back, near a left sidebone, and near
a right sidebone. We also attached other four vibrators in middle points between above four points.
We used the geomagnetic sensor(TMC3000NF by NEC Tokin) to detect an orientation of a user. We used IPS-5100G (by Sony) as a GPS. We used the spherical trigonometry to calculate a relative direction and distance to a destination.
We used a microcomputer (PIC18F452 by MicroChip) to control sensors and vibrators. The functions of the microcomputer are as follows: (1) controlling vibrators and LEDs based on input data from sensors, and (2) communicating with host PC/PDA.

We have proposed four applications, that is, (1) FeelNavi for human navigation systems, (2) FeelSense for
location-aware information services, (3) FeelSeek for search of lost properties, and (4)FeelWave for entertainments.

FeelNavi is an application of a human navigation system using tactile information. We aim at realizing a novel human navigation system with which users can intuitively reach destinations only by walking toward the direction of vibration. In the prototype system, a user register a latitude and a longitude of her/his destination with a host PC/PDA, then the ActiveBelt activates the specified vibrator based on a current position and an orientation of the user. We express a distance to a destination using pulse intervals of vibration. When a user comes nearer to the destination, pulse intervals of vibration become shorter.

- Brief explanation and usage of ActiveBelt. (Introduced in a NHK BS TV program.)

activebelt-bs-e.mov (QuickTime，320 x 240, 1min 30 sec，20 M)

#You can play these videos with QuickTimePlayer6.0 or later.

• Tsukada, K. and Yasumrua, M.: ActiveBelt: Belt-type Wearable Tactile Display for Directional Navigation, Proceedings of UbiComp2004, Springer LNCS3205, pp.384-399 (2004). [PDF]