On Dynamic Extension Controller for Stabilizing a Two Link Planar Flexible Manipulator

Toshimi Shimizu,MinoruSasaki 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper derives a tip position controller for a two link planar flexible manipulator based on the dynamic extension technique and the potential enegy shaping technique. Dynamics of the manipulator being described by a set of non-linear ordinary and partial differential equations is expanded by connecting a nexternal system that has it sown dynamics and generalized coordinats. Then the potential energy shaping technique for the combined system derives a novel tip position controller that ensures stability of a desired confiuration in the sense of Lyapunov. A numerical simulation confirms the validity of the proposed controller.

Two-Degree-of-Freedom Control of a Stacker Crane

Minoru Sasaki,Toshimi Shimizu,Kengo Suzuki,Shingo Naito,Satoshi Ito 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper presents a motion control of a stacker crane applying a two-degree-of-freedom control. The two-degree-of-freedom control system consists of a feed forward controller based on an inverse system and a feed backcontroller with suppressing the vibration effectively and stabilizing. Feedback control of the motion of the stacker crane is derived by considering the time rate of change of the total energy of the system. This approach has the advantage overthe conventional methods in the respect that it allows one to deal directly with the system’s partial differential equations without resorting to approximations. The paper concludes by presenting some numerical results and experimental results for a special case using a proposed control system. These results show that the two-degree-of-freedom control system can realize faster and precise tracking control of the flexible stacker crane system.

Self-Tuning Control of a Two-Link Flexible Manipulator using Neural Networks

Minoru Sasaki,Akihiro Asai,Toshimi Shimizu,Satoshi Ito(편집자) 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In this paper, a self-tuning control of a two-link flexible manipulator using neural networks is presented. The neural networks learn the gains of PI controllers for the flexible manipulator. Numerical results show that this presented neural network control system can suppress the vibration of the flexible manipulator and track the desired joint angles.Simulation results show that the self-tuning control system using neural network can be used effectively for the position control of the two-link flexible manipulator.

Novel Silica Nanotubes Using a Library of Carbohydrate Gel Assemblies as Templates for Sol-Gel Transcription in Binary Systems

정종화,이심성,Seiji Shinkai,Rika Iwaura,Toshimi Shimizu* 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

Self-assembly of glycolipids on silica nanotube templates yielding hybrid nanotubes with concentric organic and inorganic layers

Ji, Qingmin,Kamiya, Shoko,Jung, Jong-Hwa,Shimizu, Toshimi Royal Society of Chemistry 2005 Journal of materials chemistry Vol.15 No.7

<P>The fabrication of organic–inorganic hybrid nanotubes organized into concentric layers is described. Self-assembly of glycolipids inside the confined nanospace of hollow cylindrical silica nanotubes produced a hybrid nanotube consisting of two concentric layers, one of silica and one of lipid. Addition of glucopyranosyl ammonium cation induced concomitant self-assembly of lipid layers on both the inner and the outer surfaces of the silica nanotube, producing hybrid nanotubes with concentric lipid–silica–lipid walls. Subsequent sol–gel reaction using these lipid–silica–lipid nanotubes resulted in the formation of more complex hybrid nanotubes with a concentric five-layered structure of silica–lipid–silica–lipid–silica. Scanning transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, and Fourier-transform infrared spectroscopy were used to confirm the formation of the concentric alternating layers of organic and inorganic materials in the hybrid nanotubes.</P> <P>Graphic Abstract</P><P>A variety of organic–inorganic hybrid nanotube structures with concentric layers have been fabricated by using a silica nanotube as a starting template. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b412725k'> </P>

Self-Assembling Structures of Long-Chain Sugar-Based Amphiphiles Influenced by the Introduction of Double Bonds

Jung, Jong Hwa,Do, Youngkyu,Lee, Young-A,Shimizu, Toshimi WILEY-VCH Verlag 2005 Chemistry Vol.11 No.19

<P>Nine phenyl glucoside or galactoside amphiphiles possessing a saturated or unsaturated long alkyl-chain group as the self-assembling unit of a highly organized molecular architecture were synthesized. Their self-assembly properties were investigated by using energy-filtering TEM (EF-TEM), SEM, CD, XRD, and FT-IR techniques. Compound 2, possessing one cis double bond in the lipophilic portion, exhibited twisted helical fibers, which formed a bilayered structure with a 3.59 nm period, while 3 exhibited helical ribbons and left-handed nanotubular structures with 150–200 nm inner diameters and a wall thickness of approximately 20 nm. Very interestingly, 4, possessing three cis double bonds, exhibited a nanotubular structure with an inner diameter of approximately 70 nm and a d spacing value of 4.62 nm. On the other hand, 7, possessing two trans double bonds in the lipophilic region, exhibited crystal- or plate-like structures, which formed a bilayer structure with a d spacing value of 3.93 nm. These results indicate that the self-assembly properties are strongly dependent on the type of double bond. Furthermore, 8 and 9, with the galactopyranose moiety, revealed helical ribbon and well-defined double helical fiber structures, respectively. These findings support the view that the orientation of the intermolecular hydrogen-bonding interaction between the sugar moieties plays a critical role in producing the nanotubular structures. According to CD and powder XRD experiments, the relatively strong intermolecular hydrogen-bonding interaction of the glucopyranoside moiety in 3 and 4 provided a highly ordered chiral packing structure. Even though these compounds formed a weak hydrophobic interaction between lipophilic groups, it led to the formation of the nanotubular structure.</P> <B>Graphic Abstract</B> <P>Sugar twists and tubes: A variety of nanostructures can be created in water by self-assembly from glucopyranosides, as well as galactopyranosides, through the introduction of cis double bonds in long alkyl-chain groups (see structures). The self-assembled nanostructures of sugar-based amphiphiles were controlled by the number of cis double bonds in the lipophilic region. <img src='wiley_img/09476539-2005-11-19-CHEM200401288-content.gif' alt='wiley_img/09476539-2005-11-19-CHEM200401288-content'> </P>

Novel Silica Nanotubes Using a Library of Carbohydrate Gel Assemblies as Templates for Sol-Gel Transcription in Binary Systems

Jung, Jong-Hwa,Lee, Shim-Sung,Shinkai, Seiji,Iwaura, Rika,Shimizu, Toshimi Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

Sugar-based gelator p-dodecanoyl-aminophenyl- ${\beta}$-D-aldopyranosides (1-3) have been shown to self-assemble in the presence of p-aminophenyl aldopyranosides. The hydrogel 1+4 showed the double-helical structure with 3-25 nm outer diameters, which is quite different from that of 1. The gel 2+5 revealed twisted ribbon structure with 30-50 nm in widths and a few micrometers of length whereas the gel 3+4 revealed the single and the bundled fiber structures. The difference in these gel supramolecular structures has successfully been transcribed into silica structures by sol-gel polymerization of tetraethoxysilane (TEOS), resulting in the doublehelical, the twisted-ribbon, the single and the multiple (lotus-shaped) hollow fiber structures. These results indicate that novel silica structures can be created by transcription of various superstructures formed in binary gels through the hydrogen-bonding interaction, and the amino group of the p-aminophenyl aldopyranosides acts as an efficient driving force to create novel silica nanotubes. Furthermore, electron energy-loss spectroscopy (ELLS) provided strong evidence for the inner hollow structure of the double-helical silica nanotube. This is a novel and successful example that a variety of new silica structures can be created using a library of carbohydrate gel fibers as their templates.

Hydrogel behavior of a sugar-based gelator by introduction of an unsaturated moiety as a hydrophobic group

Jung, Jong Hwa,Rim, Jeong Ah,Han, Won Seok,Lee, Soo Jin,Lee, Young Joo,Cho, Eun Jin,Kim, Jong Seung,Ji, Qingmin,Shimizu, Toshimi Royal Society of Chemistry 2006 Organic & Biomolecular Chemistry Vol.4 No.10

<P>The new sugar-based gelators 1 and 2 were synthesized, and their gelation abilities were evaluated in organic solvents and in water. Compound 1 gelates both water and organic solvents whereas 2 gelates only organic solvents. Superstructural difference between hydrogel 1 and organogel 2 was investigated by CD, TEM, AFM, <SUP>1</SUP>H NMR and XRD. Hydrogel 1 displays a well-developed helical ribbon structure with 20–150 nm diameter and a length of several hundred µm whereas organogel 2 shows a twisted fiber structure of diameter 20 nm. CD measurements of hydrogel 1 and organogel 2 indicate that hydrogel 1 maintains a well-ordered chiral structure whereas organogel 2 maintains a relatively disordered chiral structure. The <SUP>1</SUP>H NMR and XRD results suggest that the hydrophobic interaction in hydrogel 1 are relatively weak, with a relatively small region interdigitated between lipophilic alkyl groups. In addition, upon irradiation at 254 nm wavelength, hydrogel 1 reveals a red coloration at 540 nm. These results indicate that the self-assembled hydrogel 1 was polymerized by UV-irradiation. The intensity of the CD spectrum of the polymerized hydrogel markedly decreased. This result indicates that upon polymerization the highly ordered chiral structure of hydrogel 1 changes to a disordered molecular packing structure.</P> <P>Graphic Abstract</P><P>The sugar-based gelator 1 possessing an unsaturated alkyl chain group formed both a hydrogel and organogels. Hydrogel 1 displays a well-developed helical ribbon structure 20–150 nm in diameter and several hundred µm in length. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b602279k'> </P>