Perceptual Attraction Force: The Sixth Force

A novel handheld force-feedback device that exploits the nonlinearity of human haptic perception. The device generates asymmetric acceleration in one cycle, a pushing or pulling sensation, to support nonverbal communication.

Enhanced Life
Most force-feedback devices must use heavy worn devices, huge air compressors, or some mechanical linkage to establish a fulcrum relative to the ground. None of them can be used freely outside the laboratory. This device is the first handheld force-feedback device that can be used outdoors. It could embedded in mobile devices such as cellular phones and iPods to create a new tool for communicating with gestures, guiding users along a path, teaching the perfect golf swing, and dancing.

The ultimate goal of this project is to enable many people to communicate with anyone, anywhere, anytime by using nonverbal information that can be easily shared beyond cultures and languages. The project examines the characteristics of human haptic perception (theory) and designs compact practical devices (implementation).

The most important innovation of this demonstration system is the novel force-feedback interface, which was designed and developed to generate asymmetric acceleration. The device induces the illusion of a pushing or pulling force with no external fulcrum. With a rotational motor for pan motion, the device can create a virtual force in an arbitrary direction on a two-dimensional plane.

Commercial angular sensors allow the device to measure the orientation of participants. The orientation data from two devices (or participants) are sent to the main computer wirelessly. The orientation of the devices is controlled to ensure that the tracks of participants intersect (they meet). The device also captures the trajectory of the participants with an infrared camera; each device is equipped with an infrared LED. By matching the trajectories, virtual footprints of the participants are displayed on the ground from overhead projectors.

The device is suitable for applications such as communication, entertainment, and education through mobile devices. In the future, all mobile devices will include this technology. Cellular phones that include this device and GPS will intuitively guide you to where you want to go even if you do not watch the screen. We also plan to use this technology to extend the capability of visually impaired people.

Emerging Technologies Sketch

Tomohiro Amemiya
NTT Communication Science Laboratories
t-amemiya (at)

Hideyuki Ando
Taro Maeda
NTT Communication Science Laboratories