Research on dynamic performance and motion control of robot manipulator

Amongst the robotics and autonomous systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. In this paper, the purpose is to research on dynamic performance and motion control of robot manipulator for the more precise, crucial and critical tasks in industry. Firstly, the forward and inverse kinematics was accurately described by obtaining the link transformation matrices from each joint in robot manipulator. To find admissible solutions along the path, the workspace of the manipulator was determined by joint limit condition and validated by actual measurement. And then, the dynamic performance of robot manipulator is researched by using the forming flexible multi-body system. Furthermore, the frequency response curves are obtained by exciting vibration simulation based on vibration model, which the predicted method was validated by comparing simulation and experimental results. Finally, the control system architecture was given and the grasping process was conducted by gripper based on motion trajectory control in the workspace

Urban building energy modeling (UBEM): a systematic review of challenges and opportunities

In recent decades, urban energy consumption and carbon emissions have expanded rapidly on a global scale. Building sector, in particular, accounts for approximately 40% of overall energy use. Urban planners and decision-makers have a significant responsibility to achieve sustainable energy and cli- mate objectives. Urban building energy modeling (UBEM) has increased in popularity in recent years as a tool for calculating urban-scale energy use in buildings with limited resources, and that facilitated the formulation of new energy policies. However, published studies of UBEM methodologies and tools lack comprehensive examinations of the potential limitations of research and the prospects of future opportunities. This paper provides a complete conceptual framework for UBEM based on extensive literature reviews and prior researchers’ work. In addition to providing a comprehensive understanding of the various UBEM approaches and tools, future research directions are explored. The results demonstrate that earlier researches did not adequately account for input uncertainty and lacked proper simulation and calibration control for algorithms/models. These challenges not only increased the workload and computational burden of modelers but also diminished the precision of model calculations. In response, this paper provides targeted recommendations for each essential phase of the present UBEM workflow, namely model input, model development, and model calibration, to address these limitations, as well as a comprehensive analysis of future prospects. The main aim of the research is to further UBEM development as a faster, more accurate and multiscale supportive tool and establish a framework for future UBEM methods

Radiation Induced Surface Modification of Nanoparticles and Their Dispersion in the Polymer Matrix

Polymer grafted inorganic nanoparticles attract significant attention, but pose challenges because of the complexity. In this work, a facile strategy to the graft polymer onto the surface of nanoparticles have been introduced. The vinyl functionalized SiO2 nanoparticles (NPs) were first prepared by the surface modification of the unmodified SiO2 using γ-methacryloxy propyl-trimethoxylsilane. The NPs were then mixed with polyvinylidene fluoride (PVDF), which was followed by the Co-60 Gamma radiation at room temperature. PVDF molecular chains were chemically grafted onto the surface of SiO2 nanoparticles by the linking of the double bond on the NPs. The graft ratio of PVDF on SiO2 NPs surface can be precisely controlled by adjusting the absorbed dose and reactant feed ratio (maximum graft ratio was 31.3 wt%). The strategy is simple and it should be applied to the surface modification of many other nanoparticles. The prepared PVDF-grafted SiO2 NPs were then dispersed in the PVDF matrix to make the nanocomposites. It was found that the modified NPs can be precisely dispersed into the PVDF matrix, as compared with pristine silica. The filling content of modifications SiO2 NPs on the PVDF nanocomposites is almost doubled than the pristine SiO2 counterpart. Accordingly, the mechanical property of the nanocomposites is significantly improved

Benzoate Anion-Intercalated Layered Cobalt Hydroxide Nanoarray: An Efficient Electrocatalyst for the Oxygen Evolution Reaction

Efficient oxygen evolution reaction (OER) catalysts are highly desired to improve the overall efficiency of electrochemical water splitting. We develop a benzoate anion-intercalated layered cobalt hydroxide nanobelt array on nickel foam (benzoate-Co(OH)(2)/NF) through a one-pot hydrothermal process. As a 3D electrode, benzoate-Co(OH)(2)/NF with an expanded interlayer spacing (14.72 angstrom) drives a high OER catalytic current density of 50mAcm(-2) at an overpotential of 291mV, outperforming its carbonate anion-intercalated counterpart with a lower interlayer spacing of 8.81 angstrom (337mV overpotential at 50mAcm(-2)). Moreover, this benzoate-Co(OH)(2)/NF can maintain its catalytic activity for 21h

Ultrafine PtO2 nanoparticles coupled with a Co(OH)F nanowire array for enhanced hydrogen evolution

In this communication, we report the in situ formation of ultrafine PtO2 nanoparticles coupled with a Co(OH)F nanowire array (PtO2-Co(OH)F NA/TM) via a facile hydrothermal treatment. The PtO2-Co(OH)F NA/TM possesses interfacial synergy derived from its favorable composition and structure. It can greatly promote water dissociation and optimize the free energy of H* adsorption, indicating high catalytic activity towards the alkaline HER

A NiCo2O4@Ni-Co-Ci core-shell nanowire array as an efficient electrocatalyst for water oxidation at near-neutral pH

It is attractive but still remains challenging to develop efficient water oxidation electrocatalysts working in a carbonate (Ci) electrolyte. In this communication, we report that a Ni-Co-Ci layer can be developed on a NiCo2O4 nanowire array supported on carbon cloth (NiCo2O4/CC) via electrochemical surface derivation of NiCo2O4. The resulting NiCo2O4@ Ni-Co-Ci core-shell nanowire array on carbon cloth (NiCo2O4@ Ni-Co-Ci/CC) exhibits high activity toward water oxidation in 1.0 M KHCO3 (K-Ci, pH = 8.3) with the over-potential requirement of 309 mV to drive 10 mA cm(-2). NiCo2O4@ Ni-Co-Ci/CC also shows long-term electrochemical stability for 20 h and a high turnover frequency of 0.464 mol O-2 s (1) at an over-potential of 600 mV

Surface Modification of a NiS₂ Nanoarray with Ni(OH)₂ toward Superior Water Reduction Electrocatalysis in Alkaline Media

Interface engineering has been demonstrated to be effective in promoting hydrogen evolution reaction (HER) in an alkaline solution. Herein, we report that the HER activity of a NiS₂ nanoarray on a titanium mesh (NiS₂/TM) in alkaline media is greatly boosted by the electrodeposition of Ni­(OH)₂ onto NiS₂ [Ni­(OH)₂–NiS₂/TM]. Ni­(OH)₂–NiS₂/TM only needs an overpotential of 90 mV to deliver 10 mA cm^–2 in 1.0 M KOH. Density functional theory calculations confirm that Ni­(OH)₂–NiS₂ has a lower water dissociation free energy and a more optimal hydrogen adsorption free energy than NiS₂