A5067119577- Nuclear Physics and Applications
- Robotic Locomotion and Control
- Atomic and Subatomic Physics Research
- Optical Coatings and Gratings
- Adaptive optics and wavefront sensing
- Advanced Measurement and Metrology Techniques
- Photonic and Optical Devices
- Advanced Surface Polishing Techniques
- Electrowetting and Microfluidic Technologies
- Advanced MEMS and NEMS Technologies
- Quantum, superfluid, helium dynamics
- Advanced optical system design
- Nuclear reactor physics and engineering
- Optical Systems and Laser Technology
- High-pressure geophysics and materials
- Radiation Detection and Scintillator Technologies
- Prosthetics and Rehabilitation Robotics
- Optical measurement and interference techniques
- Innovative Energy Harvesting Technologies
- Nonlinear Optical Materials Research
- Robotic Mechanisms and Dynamics
- Photorefractive and Nonlinear Optics
- Control and Dynamics of Mobile Robots
- Laser-Matter Interactions and Applications
- Interactive and Immersive Displays
RIKEN Center for Advanced Photonics
2015-2024
Nitto RIKEN (Japan)
2016-2024
RIKEN
2014-2020
Nippon Soken (Japan)
2019
The University of Tokyo
2009-2014
Waseda University
2003-2007
Kanagawa University
2005
Kanagawa Institute of Technology
2004
This paper describes the mechanism of biped locomotor, WL-16 (Waseda Leg No. 16), its compliance control method and experiments carrying a human. robot is developed based on WL-15's basic design using new gimbals' mechanisms with small backlash linear actuators dealing heavy payload wide movable range. Walking human are successfully completed effectiveness WL-16's confirmed.
Abstract Full elements of second-order nonlinear optical (NLO) tensor can be completely characterized for an organic NLO crystal the first time. As-grown bulk N-benzyl-2-methyl-4-nitroaniline (BNA) was processed to expose (100) and (010) orientations with fine surfaces by using precision lathe diamond blade. Then, every five nonvanishing coefficient BNA determined quantitatively precisely crystals based on 1st-kind Maker fringe measurements. Our method makes it possible clarify uncertain...
Single-shot optical imaging based on ultrashort lasers has revealed nonrepetitive processes in subnanosecond timescales beyond the recording range of conventional high-speed cameras. However, nanosecond photography without sacrificing short exposure time and image quality is still missing because gap recordable between ultrafast electronic Here, we demonstrate ultrawide time-range using a spectrum circuit that produces interval-tunable pulse trains while keeping durations. We capture shock...
Biped walking is easily adaptable to rough terrain such as stairs and stony paths, but the walk speed energy efficiency on flat ground not so effective compared with wheeled locomotion. In this paper, we propose a biped robot be able or wheel according conditions. For locomotion, WS-2 (Waseda Shoes -No. 2) developed which composed of DC motor, spherical caster two rubber pads each foot. attached feet WL-16 Leg 16) that world's first biped-walking capable carrying human. Also, path planning...
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We present sequentially timed all-optical mapping photography (STAMP) with a slicing mirror in branched 4f system for an increased number of frames without sacrificing pixel resolution. The spectrally separates the laser light path into multiple paths by placed Fourier plane. Fabricated ultra-precision end milling process, has 18 facets differing angles. used boosted STAMP to observe dynamics ablation two image sensors which captured subsequent at frame rate 126 billion per second,...
Integral Field Spectroscopy (IFS) is an observational method to obtain spatially resolved spectra over a specific field of view (FoV) in single exposure. In recent years, near-infrared IFS has gained importance observing objects with strong dust attenuation or at high redshift. One limitation existing instruments their relatively small FoV, less than 100 arcsec$^2$, compared optical instruments. Therefore, we have developed (0.9-2.5 $\mathrm{\mu}$m) image-slicer type integral unit (IFU)...
This paper reports a development of transparent planar electrostatic actuator, which is useful for constructing interactive human-computer interfaces on flat panel displays. The actuator pair plastic films with strip electrodes in three-phase connections. Half the each film are X electrodes, and rest Y electrodes; forces excited by applying voltage to these drive at speeds proportional excitation frequency. stator has its alternately arranged four-by-four checkerboard pattern. slider square...
This paper reports the modeling and analysis of a linear resonant electrostatic induction motor, with an imbalance in capacitance taken into consideration. The motor is asynchronous consisting film-type stator slider three-phase electrodes, driven by voltage applied to stator. electrodes are connected three coils, which enable rise high at resonance, producing large thrust force. highly sensitive capacitance, particularly resonance. A model developed relate each formed among symmetrical...
Results of this study demonstrated that electroless nickel-phosphorus (NiP) plated metal substrate is an excellent material for producing large aspherical neutron-focusing supermirrors. A plano-elliptical supermirror comprising two metallic segments was fabricated using single-point diamond cutting, precision polishing and coating. The average surface roughness the substrates approximately 0.3 nm rms. For evaluation, focusing installed at SOFIA neutron reflectometer, showing high...
This paper details methods for the precision design and fabrication of neutron-focusing supermirrors, based on electroless nickel plating. We fabricated an elliptic mirror neutron reflectometry, which is our second improved from first. The a 550-millimeter-long segmented assembled using kinematic couplings, with each segment figured by diamond cutting, polished colloidal silica, supermirror coated through ion-beam sputtering. was evaluated beams, reflectivity found to be 68-90% at critical...
This paper describes a walking control method on inclined planes for biped locomotor. The consists of position control, virtual compliance and posture control. Parameters the are changed continuously in support swing phases. orientation robot's waist is kept level by Several experiments conducted using WL-16R (Waseda Leg - No. 16 Refined). has achieved stable unknown method, effectiveness confirmed.
This paper details the development of a precise assembly two supermirrors for neutron-focusing, designed installation in neutron reflectometer SOFIA at BL16 J-PARC MLF to intensify illumination small samples. The are sputtered on metal substrates, whose surfaces coated with amorphous Ni-P plating, and figured by diamond cutting polished subnanometer roughness. Special care is taken while polishing substrates reduce waviness surface roughness achieving sharp focusing spot uniform...
This paper describes a control method for stable biped walking on uneven terrain. The consists of position and compliance control. In order to realize dynamic human living environment, locomotor is controlled by the based compensatory motion. Also, in this research, reduce magnitude impact forces guarantee landing ground, position-based virtual introduced. Several experiments terrain are conducted using WL-15 (Waseda Leg-15) effectiveness confirmed.
This paper describes the development of support torque reduction mechanism for a biped locomotor with leg mechanisms using Stewart platforms, designed heavy payload and low power consumption during walking. The basic design this was decided through preliminary experiments. Each robot is equipped consisting 2 gas springs different reaction forces, which are switched according to swing/support phase. experiment measuring motor current walking maximum confirmed effectiveness mechanism.
This study entailed the successful deployment of a novel neutron interferometer that utilizes multilayer mirrors. The apparatus facilitates precise evaluation wavelength dependence interference fringes utilizing pulsed source. Our achieved an impressive precision 0.02 rad within 20-min recording time. Compared to systems using silicon crystals, measurement sensitivity was maintained even when simplified disturbance suppressor. By segregating beam paths entirely, we measurements...
Zero-gap-type reactors with gas diffusion electrodes (GDE) that facilitate the CO
To date, many control methods have been studied, assuming that the soles of a biped walking robot contact ground as four points. It is difficult for with rigid and flat to maintain four-point on uneven terrain. means can lose its balance. solve this kind problem, we should study not only stability but also foot mechanisms. In paper, new system, WS-1 (Waseda shoes $no.1), proposed contact. This system consists cam-type locking mechanism. attached feet WL-16 leg - no.16) world's first...
Neutron reflectometry (NR) is a powerful tool for providing insight into the evolution of interfacial structures, example via operando measurements electrode–electrolyte interfaces, with spatial resolution nanometres. The time NR, which ranges from seconds to minutes depending on reflection intensity, unfortunately remains low, particularly small samples made state-of-the-art materials even latest neutron reflectometers. To overcome this problem, large-area focusing supermirror manufactured...
Electrostatic film actuator is a thin, lightweight and flexible composed of two plastic films with fine-pitched electrodes embedded in them. In this paper, we report novel driving method for the actuator, which one (the slider film) are pre-charged DC high voltages, driven by AC voltages applied to other stator film). Typically, has been applying three-phase both films; method, required connections feeding wires, whose tensions causing disturbance its motion. The advantage pre-charging that...
As a transmission grating, surface-relief (SR) grating with sawtooth shaped ridges and volume phase holographic (VPH) are widely used for instruments of astronomical observations. However the SR is difficult to achieve high diffraction efficiency at angular dispersion, VPH has low in orders. We propose novel gratings that solve these problems. introduce hybrid grism which combines refractive index prism replicated an acute apex angle. The birefringence (B-VPH) contains anisotropic medium,...
This paper describes a mechanical design concept for large ellipsoidal neutron-focusing supermirror in full figure of revolution, which is currently under development its utilization neutron resonance spin echo spectrometer VIN ROSE at J-PARC/MLF.The mirror an assembly 54 segments, 900 mm long as whole.Each segment deposited on polished metallic substrate with electroless nickel plating.As base precise assembly, cagelike octadecagonal structure introduced.The exemplifies how free-form...