Man-machine interface for modular robot systems

A modular robot is composed of multiple modules, each comprising a sensor, an actuator, and a control system. Each module accumulates information about its own sensor, actuator, and connections to other modules, as well as communication information between adjoining modules. The user obtains this information via an interface, and can thus recognize the state of the robot and issue commands. However, when the number of modules becomes large, the amount of information sent from the modules becomes too much for the user to deal with effectively. Naturally, it also becomes more difficult for the user to issue commands to the modular robot as the number of modules increases. In this study, we developed an interface to present, in a simple manner, information aggregated in a certain module from other modules, and we examined its effectiveness in a modular robot composed of these modules.     

Autonomous reconfiguration of robot shape by using Q-learning

A modular robot can be built with a shape and function that matches the working environment. We developed a four-arm modular robot system which can be configured in a planar structure. A learning mechanism is incorporated in each module constituting the robot. We aim to control the overall shape of the robot by an accumulation of the autonomous actions resulting from the individual learning functions. Considering that the overall shape of a modular robot depends on the learning conditions in each module, this control method can be treated as a dispersion control learning method. The learning object is cooperative motion between adjacent modules. The learning process proceeds based on Q-learning by trial and error. We confirmed the effectiveness of the proposed technique by computer simulation.     

Nanosize Cation‐Disordered Rocksalt Oxides: Na2TiO3–NaMnO2 Binary System

To realize the development of rechargeable sodium batteries, new positive electrode materials without less abundant elements are explored. Enrichment of sodium contents in host structures is required to increase the theoretical capacity as electrode materials, and therefore Na‐excess compounds are systematically examined in a binary system of Na₂TiO₃–NaMnO₂. After several trials, synthesis of Na‐excess compounds with a cation disordered rocksalt structure is successful by adapting a mechanical milling method. Among the tested electrode materials, Na_1.14Mn_0.57Ti_0.29O₂ in this binary system delivers a large reversible capacity of ≈200 mA h g^?1, originating from reversible redox reactions of cationic Mn³⁺/Mn⁴⁺ and anionic O^2?/O^n? redox confirmed by X‐ray absorption spectroscopy. Holes in oxygen 2p orbitals, which are formed by electrochemical oxidation, are energetically stabilized by electron donation from Mn ions. Moreover, reversibility of anionic redox is significantly improved compared with a former study on a binary system of Na₃NbO₃–NaMnO₂ tested as model electrode materials.     

FFS‐mode OS‐LCD for reducing eye strain

In order to reduce eye strain, a driving method for reducing flickers of liquid crystal display (LCD) is devised. For this driving, an oxide semiconductor (OS) is used in a backplane, liquid crystal and alignment layer materials are optimized, and a fringe field switching (FFS) mode with a structurally formed storage capacitor is used. This work reveals that suitable usages of positive and negative liquid crystals differ from each other according to their characteristics. This work also describes an OS‐LCD with a touch sensor we fabricated for mobile devices, which proves the possibility of reducing‐eye‐strain technology (REST) with reduced flickers.     

Microhardness and Transparency of an La-Si-O-N Oxynitride Glass

An oxynitride glass containing 18 at.% N was prepared under high N₂ pressure. The glass was transparent and very hard, with a Vickers hardness of 12.0 GPa.     

Thermal behavior and reactivities of prepolymers prepared from aromatic biscyanamides and bismaleimide

Novel polymers obtained by reaction of aromatic biscyanamide and bismaleimide compounds were investigated. By heating 4,4′-methylene bis(o-methylphenylcyanamide) (BMCA) with 4,4′-methylene bis (phenylmaleimide) (BMI) at 120°C in N,N-dimethylformamide (DMF), prepolymers were obtained by the conversion of cyanamide to cyanoguanidine and the addition of an imino group on the double bond of maleimide. The prepolymer showed suitable behavior for thermosetting resin used in molding, i.e., it melted temporarily and then polymerized in an isochronal heating process (5°C/min). On heating above 170°C, the prepolymer could polymerize with ring formation of melamine and isomelamine. The cured product had good heat-resistant properties.     

Dynamic mechanical properties and adhesive strengths of epoxy resins modified with liquid rubber. I. Modification with ATBN

The dynamic mechanical properties and the adhesive strengths of Epikote 828 and Epikote 828-ATBN blend systems were investigated. The ATBN blend systems were proved to be completely incompatible with the dynamic mechanical measurement and also fitted well with Takayanagi's model which was designed for completely incompatible two-phase systems. The epoxy resin had a nonreacted part when cured at room temperature. The blending of ATBN reduced the nonreacted part of the epoxy resin, and made contributions to the adhesive strengths. In the case of tensile test of crosslap specimens using aluminium as adherends, the adhesive strengths of ATBN blend systems were almost 1.5-fold of those of epoxy resin without blending of ATBN. As for wood adherends, the maximum of the adhesive strengths was found at 60°C for epoxy resin without blending of ATBN, and at 0°C for ATBN blend systems. The facts meant that there were mutual interactions between the adhesive strengths and the viscoelastic behavior of the adhesive polymers in the two-phase systems as observed in completely miscible polymer blends. There was not pronounced distinction between epoxy resins without blending of ATBN and ATBN blend system, as to the shear adhesive strengths.     

<Emphasis Type="SmallCaps">d</Emphasis>-Pinitol in Fabaceae: an Oviposition Stimulant for the Common Grass Yellow Butterfly, <Emphasis Type="Italic">Eurema mandarina</Emphasis>

The common grass yellow butterfly, Eurema mandarina (formerly Eurema hecabe mandarina) (Lepidoptera, Pieridae), recently has been separated taxonomically from a subtropical population of Eurema hecabe in Japan. This species is widely distributed in the temperate region of Japan, and feeds mainly on various ligneous plants within the Fabaceae. We attempted to identify an oviposition stimulant for E. mandarina from its primary hosts, Albizia julibrissin and Lespedeza cuneata. In both hosts, crude extract and an aqueous fraction elicited oviposition responses from gravid females. A polar subfraction of the aqueous fraction also stimulated high oviposition-stimulatory activity, comparable to the original aqueous fraction, suggesting that E. mandarina females use water-soluble compounds for host recognition. Subsequent activity-directed fractionation by ion exchange chromatography indicated that one of the key substances was contained in the neutral/amphoteric fraction. Chemical analyses revealed that the active fractions of both hosts contained d-(+)-pinitol as the major component. We examined female responses to authentic d-pinitol and found that it induced oviposition responses at concentrations greater than 0.1 %. Since this cyclitol is omnipresent in Fabaceae, we conclude that d-pinitol plays a role in mediating oviposition of E. mandarina on fabaceous plants.     

Seal spot welding of steel and aluminium alloy by resistance spot welding: dissimilar metal joining of steel and aluminium alloy by Zn insertion

This research concerns a dissimilar metal joining of steel and aluminium (Al) alloys by means of zinc (Zn) insertion. The authors propose a joining concept for achieving strong bonded joints between Zn-coated steel and Al alloys. A eutectic reaction between Zn in the Zn coating and uniform Al–Fe intermetallic compound (IMC) layer at the joint interface, leading to a strong bonded joint. The ultimate aim of this research was to apply this joining concept in the resistance spot welding process for manufacturing vehicle bodies. As a practical issue characteristic to joints of dissimilar metals, anticorrosion measures against electrochemical corrosion must be undertaken. If there is moisture near a joint interface of dissimilar metals, electrochemical erosion will progress. Therefore, a sealing function that could prevent moisture intrusion is required. By applying the above-mentioned welding process to a set of metals with thermosetting resin spread in between, we realized seal spot welding, which not only prevented moisture intrusion but also retained high tensile strength. In this research, first, a cyclic corrosion test was performed on the seal spot-welded joint of galvanized (GI) steel, a steel grade widely distributed in Japan, and Al alloy was bonded by seal spot welding, and the following topics are discussed. Complete removal of sealant from the joint interface is the key to realizing the high tensile stress joint, because remaining sealant will lead to reduction in tensile strength. Therefore, heat generation at the interface was monitored by measuring electrical current and potential difference between the two electrodes, and a precise temperature control was performed. Moreover, the bonding process was clarified by stepwise analysis of the joint interface using optical microscopy, and a guideline for producing strong joints was proposed. And finally, a TEM observation also confirmed that the interface structure of the seal spot-welded joint was the same as joints without the resin; a thin and uniform Al–Fe IMC layer was formed and a strong metallurgical bonding was achieved.     

Control strategy of developed mechanical actuator in measuring hole surface parameter

This paper presents the control strategy of a new type of mechanical actuator used to help in measuring hole surface parameter. The actuator can carry up to a load of 26 kg during measurement. Often, the measurement unit’s attitude is misaligned due to the force acting on it. Actuator is used in order to control the misalignment of such system during measurement. In this research, the complete measurement system consists of a servo motor, a laser diode, a laser interferometer, an optical system, as well as an integrated computer system. The main purpose of this research is to develop the new type of actuator which can control the attitude (position and inclination) of a measurement probe. The experimental results show that it is possible to carry mechanically the loads up to 26 kg of the measurement probe during measurement of deep surface. In this paper, the developed actuator’s control strategy has been discussed widely in order to measure the surface parameter successfully.