Seki Inoue

Active touch perception produced by airborne ultrasonic haptic hologram

A method to present volumetric haptic objects in the air using spatial modulation of ultrasound is proposed. Previous methods of airborne ultrasonic tactile display were based on vibrotactile radiation pressure and sensor feedback systems, which result in low spatial receptive resolution. The proposed approach produces a spatially standing haptic image using stationary ultrasonic waves that enable users to touch 3D images without depending on vibrotactile stimulation and sensor feedback. The omnidirectional spatial modulated haptic images are generated by a phased array surrounding a workspace, which enables enough power to feel shapes without vibrotactile technique. Compared with previous methods, the proposed method can create a completely silent image without temporal ultrasonic modulation noise that is free of the problems caused by feedback delay and errors. To investigate the active touch profiles of an ultrasonic image, this paper discusses a method to synthesize a haptic holographic image, the evaluation of our algorithm, and the results of pressure measurement and subjective experiments.

HaptoClone (Haptic-Optical Clone) for Mutual Tele-Environment by Real-time 3D Image Transfer with Midair Force Feedback

In this paper, we propose a novel interactive system that mutually copies adjacent 3D environments optically and physically. The system realizes mutual user interactions through haptics without wearing any devices. A realistic volumetric image is displayed using a pair of micro-mirror array plates (MMAPs). The MMAP transmissively reflects the rays from an object, and a pair of them reconstructs the floating aerial image of the object. Our system can optically copy adjacent environments based on this technology. Haptic feedback is also given by using an airborne ultrasound tactile display (AUTD). Converged ultrasound can give force feedback in midair. Based on the optical characteristics of the MMAPs, the cloned image and the user share an identical coordinate system. When a user touches the transferred clone image, the system gives force feedback so that the user can feel the mechanical contact and reality of the floating image.

HORN: the hapt-optic reconstruction

In this paper we propose a system that superposes a haptic sensation on a mid-air floating image based on ultrasonic standing waves. Conventional approaches of using airborne traveling ultrasounds could only apply weak pressure to the finger surface from a certain angle and thus a limited haptic sensation. Also, the ultrasounds generated air flow as a side-effect [Hoshi et al. 2009].

A pinchable aerial virtual sphere by acoustic ultrasound stationary wave

In this paper, we propose a system to generate aerial virtual spheres which invokes tactile sensation and is omni-directionally pinchable. The acoustic radiation force of ultrasound stationary waves is known in the field of non-contact micro manipulation. This force applied to a small object in the stationary wave is in proportion to the gradient of the square of the acoustic pressure and directing from anti-node to node. We demonstrate a prototype system consisting of 996 transducers which generates a focal anti-node point at the center of the workspace. We performed the acoustic pressure distribution analysis and subjective experiments. As a result, it is discovered that the virtual sphere was sensed as the same size as theoretically expected.

Electronically steerable ultrasound-driven long narrow air stream

Acoustic streaming, which is the unidirectional movement of a medium driven by its internal intense acoustic vibrations, has been known for more than a century. Despite the long history of research, there have been no scientific reports on the creation of long stretching steerable airflows in an open space, generated by ultrasound. Here, we demonstrated the creation of a narrow, straight flow in air to a distance of 400 mm from an ultrasound phased array emitting a Bessel beam. We also demonstrated that the direction of the flow could be controlled by appropriately tuning the wavefronts of the emission from the phased array. Unlike conventional airflows such as those generated by jets or fans, which decelerate and spread out as they travel farther, the flow that we created proceeded while being accelerated by the kinetic energy supplied from the ultrasound beam and keeping the diameter as small as the wavelength. A flow of 3 m/s with a 10 mm diameter extended for several hundreds of millimeters in a room ...

Producing airborne ultrasonic 3D tactile image by time reversal field rendering

In this paper, we propose a method to render ultrasound pressure distribution in an inhomogeneous field by surrounding phased array especially for the purpose of invoking tactile sensation to human skins. Our previous work showed that ultrasound stationary radiation force can invoke tactile sensation for users finger in 3D cavity which is surrounded by ultrasound transducers. However, disturbance of an acoustic wave field by users hand is not negligible and therefore the sensed haptic force decreases. In addition, ways to present arbitrary spatial form are also desired. The proposed method renders the pressure field and reconstructs it by finite element method and time reversal method. This method can be applied to inhomogeneous field with the presence of fingers or palms and can create complicated images.

High Spatial Resolution Midair Tactile Display Using 70źkHz Ultrasound

We fabricated a midair tactile display using a 70i?źkHz airborne ultrasound. The spatial resolution of the display was improved 1.75 times compared with the conventional 40i?źkHz ultrasound tactile display. Since the focal spot diameter was smaller than a finger pad, the user could perceive a localized spot on the finger pad. In the experiment determining the physical properties, we found that the ultrasound attenuation at 70i?źkHz was comparable to that at 40i?źkHz. The small focal spot was successfully created as expected using the theory. The psychophysical experimental results showed that the minimum perceivable radiation force for the focal spot of 70i?źkHz was smaller than that for the 40i?źkHz case in average under 40 or 100i?źHz modulations, and the smaller focal spot was easier to perceive. We also conducted a comparison test of the perceived force area with real contacts.

Designing stationary airborne ultrasonic 3D tactile object

In this paper we denote the system to display aerial 3D virtual tactile object by using airborne ultrasound. By controlling acoustic pressure distribution in the cavity surrounded by ultrasonic phased array, stationary and freely touchable aerial virtual object can be achieved without counting on sensor feedback. We address a method to render pressure distribution to obtain some specific forms. We implemented phased array system mounting about four thousand transducers three-dimensionally. Aerial three dimensional haptic image superimposed on three dimensional optic image are achieved with this device.

VibVid: VIBration Estimation from VIDeo by using Neural Network.

Along with advances in video technology in recent years, there is an increasing need for adding tactile sensation to it. Many researches on models for estimating appropriate tactile information from images and sounds contained in videos have been reported. In this paper, we propose a method named VibVid that uses machine learning for estimating the tactile signal from video with audio that can deal with the kind of video where video and tactile information are not so obviously related. As an example, we evaluated by estimating and imparting the vibration transmitted to the tennis racket from the first-person view video of tennis. As a result, the waveform generated by VibVid was almost in line with the actual vibration waveform. Then we conducted a subject experiment including 20 participants, and it showed good results in four evaluation criteria of harmony, fun, immersiveness, and realism etc. CCS Concepts •Human-centered computing → Haptic devices; •Theory of computation → Models of learning; •Hardware → Haptic devices;

HaptoCloneAR: mutual haptic-optic interactive system with 2D image superimpose

In our previous study called HaptoClone, a user can interact with optically copied objects from the adjacent workspace with haptic feedback. In this study, we added two displays and two half mirrors in the system, so that users can see and touch not only cloned real objects but also 2D superimposed virtual screens. This system enables users to experience more various contents such as a videophone, fighting games, and other entertainments so called AR (Augmented Reality) or MR (Mixed Reality) with haptic feedback.