Hideyuki Ando

Lead-me interface for a pulling sensation from hand-held devices

When a small mass in a hand-held device oscillates along a single axis with asymmetric acceleration (strongly peaked in one direction and diffuse in the other), the holder typically experiences a kinesthetic illusion characterized by the sensation of being continuously pushed or pulled by the device. This effect was investigated because of its potential application to a hand-held, nongrounded, haptic device that can convey a sense of a continuous translational force in one direction, which is a key missing piece in haptic research. A 1 degree-of-freedom (DOF) haptic device based on a crank-slider mechanism was constructed. The device converts the constant rotation of an electric motor into the constrained movement of a small mass with asymmetric acceleration. The frequency that maximizes the perceived movement offered by the haptic device was investigated. Tests using three subjects showed that for the prototype, the best frequencies were 5 and 10 cycles per second.

Virtual force display: direction guidance using asymmetric acceleration via periodic translational motion

This paper describes the development of a handheld haptic display based on a new force perception method. The method uses periodic translational motion to create asymmetric acceleration leading to a virtual force vector. The method is based on the sigmoidal relationship between perception and physical quantities (tactile and proprioceptive sensations); humans more strongly feel rapid acceleration than slow acceleration. A prototype of the haptic display that generates one-directional force using a relatively simple mechanism is fabricated and evaluated. Experiments verify the feasibility of the proposed method by examining the effect of the frequency of acceleration and amplitude of the force on the perception of the virtual force vector.

Shaking the world: galvanic vestibular stimulation as a novel sensation interface

We developed a novel sensation interface device using galvanic vestibular stimulation (GVS). GVS alters your balance. Our device can induce vection (virtual sense of acceleration) synchronized with optic flow or musical rhythms. The device can also induce lateral walking towards the anode while human walking.

Wearable robotics as a behavioral interface - the study of the Parasitic Humanoid

The Parasitic Humanoid (PH) is a wearable robot for modeling nonverbal human behavior. This anthropomorphic robot senses the behavior of the wearer and has the internal models to learn the process of human sensory motor integration, thereafter it begins to predict the next behavior of the wearer using the learned models. When the reliability of the prediction is sufficient, the PH outputs the errors from the actual behavior as a request for motion to the wearer. Through symbiotic interaction, the internal model and the process of human sensory motor integration approximate each other asymptotically.

Virtual acceleration with galvanic vestibular stimulation in a virtual reality environment

This study describes the relation between the vection produced by optical flow and that created by galvanic vestibular stimulation. Vection is the illusion of self motion and is most often experienced when an observer views a large screen display containing a translating pattern. This illusion has only limited fidelity and duration unless it is reinforced by confirming vestibular information. Galvanic vestibular stimulation (GVS) can directly produce the sensation of vection.

Application of a multi-DOF ultrasonic servomotor in an auditory tele-existence robot

A multi-degree-of-freedom (DOF) ultrasonic motor can rotate in three DOFs and does not generate noise. In addition, with an appropriate preloading mechanism, it can generate high torque for its size. The multi-DOF ultrasonic motor is, therefore, anticipated for use as a servomotor in the next generation of robots. However, for several reasons, there have been few applications of multi-DOF ultrasonic motors. One reason is the difficulty in designing a proper preloading mechanism for the motor and the limitation of the size of the stators. Another is the difficulty in developing a control algorithm, due to the motors complex and changing dynamical characteristics, and the serious jaggy motion caused by its very quick response. This paper proposes a preloading mechanism and control algorithm for a multi-DOF ultrasonic motor, considering the motors application to an actual auditory tele-existence robot, TeleHead. TeleHead is an elaborate dummy head robot that has a 3-DOF neck mechanism. The proposed methods achieve smooth and fast multi-DOF rotating motion of the dummy head with little time delay. In the preloading method, tensioned springs generate high preloading force and make up for the lack of torque by compensating for the resistance torque generated by the inclining motion of the dummy head. In the control algorithm, high-DOF motion is managed by high-frequency switching of the rotating axis, and smooth and quick trajectory tracking motion is achieved by introducing feed-forward control using an inverse model, with multiresolution acquired by feedback-error learning. Experimental results verify the high performance of these methods.

Phantom-DRAWN: direction guidance using rapid and asymmetric acceleration weighted by nonlinearity of perception

This paper describes the design of a novel force perception method and the development of a handheld force display based on the method. The method is based on the nonlinear characteristics of human tactile perception; humans feel rapid acceleration more strongly than slow acceleration. The method uses periodic prismatic motion to create asymmetric acceleration leading to a virtual force vector. A prototype of the handheld force display that generates one-directional force using a relatively simple mechanism was built, and its performance tested in terms of both physical and perceptual characteristics. We verify the feasibility of the proposed method through experiments that determine the displays motors rotational frequency that maximizes the perception of the virtual force vector.

Shoe-shaped interface for inducing a walking cycle

We propose a shoe-shaped interface designed to induce a specific walking cycle, and investigate stimulation techniques for effective induction of the walking cycle. The proposed interface is useful for walking navigation system, which enables the wearers locomotion without paying attention to surrounding circumstances. The interface consists of a vibration motor for stimulation and pressure sensors for measuring walking cycle. Using sensory-motor synchronization of human body, this interface can induce a walking cycle effectively without mechanical constraint. The results of our experiments indicate that vibration stimuli at heel grounding timing enable effective induction and that wearers can smoothly shift their walking cycles to the indicated cycle, if the shift of the stimulation cycle is within the range of -100 and +150 ms from their walking cycle.

Mechanisms Underlying Referral of Thermal Sensations to Sites of Tactile Stimulation

When three stimulators are simultaneously touched with the middle three fingers of one hand but only the outer two stimulators are cooled or heated, the central (neutral) stimulator is also perceived to be cold or warm. This phenomenon is known as thermal referral and it shares phenomenological similarities with filling-in, in which the discontinuity in the signals of interest can be compensated perceptually on the basis of the spatially adjacent context. Although the mechanisms underlying filling-in have been well substantiated, those underlying thermal referral are still poorly understood. In the present study, we examined the intensity perception of the sensation resulting from thermal referral with human participants. We found that the sensation was uniform among the three fingers, but its apparent intensity was always lower than the physical intensity applied to the outer two fingers. These results indicate that the thermal uniformity perceived under thermal referral is not created by the brains interpolating the thermal changes applied to the outer two fingers, as one would expect for those induced by typical filling-in. Instead, the thermal changes applied to the outer two fingers are summated and redistributed to all the fingers in contact. Our findings suggest that thermal referral is mediated by two separate processes. One determines the apparent intensity from the physical intensity and the areal extent of the thermal stimulation; the other determines the localization of the resulting sensation from the apparent sites of tactile stimulation.

Nail-mounted tactile display for boundary/texture augmentation

We developed a device that can superimpose tactile information onto an object displayed on a computer monitor. With this device, we can present tactile sensations of boundaries or textures corresponding to the visual image. The device is composed of a small voice coil, and the tactile sensations are generated by controlling the modulation of the waveforms. For demonstration proposes, the device is integrated with a tool that allows users to draw a picture easily with their fingertips while experiencing tactile feedback.