Moscow State Institute of Electronic Engineering

Collaborative assembly represents one of the most prevalent practical applications of collaborative robots in intelligent manufacturing. Developing intelligent systems to ensure safety of collaborative assembly processes requires a special attention. In this work, we introduce a visual safety system designed to monitor hazardous situations that may occur during collaborative assembly, potentially resulting in operator injuries. Unlike many other vision-based systems, we solely rely on data from two RGB cameras, without acquiring additional depth information from other sensors. These cameras provide top and side projections of a collaborative workspace. The safety system assesses a current level of a risk by employing two neural network YOLOv8-cls models. These models are pretrained on the ImageNet dataset and subsequently fine-tuned on our dataset. Upon identifying a potential hazard, the system employs our proposed algorithm to determine whether to slow down or halt a robot’s motion. Additionally, the system integrates with a visual control system that utilizes an operator gesture control throughout an assembly process. We further conduct experiments to compare our system’s assessment with an assessment of human experts. An analysis of the experiments demonstrated a high level of correlation between the evaluations of the autonomous system and the human experts. Benefits of the proposed system encompass its relative cost-effectiveness and ease of setup.

In this paper, we consider the equation $u_{xx}+Q(x)u+P(x)u^{3}=0$ where Q(x) and P(x) are periodic functions. It is known that, if P(x) changes sign, a “great part” of the solutions for this equation are singular, i. e., they tend to infinity at a finite point of the real axis. Our aim is to describe as completely as possible solutions, which are regular (i. e., not singular) on $\mathbb{R}$. For this purpose we consider the Poincaré map $\mathcal{P}$ (i. e., the map-over-period) for this equation and analyse the areas of the plane $(u,u_{x})$ where $\mathcal{P}$ and $\mathcal{P}^{-1}$ are defined. We give sufficient conditions for hyperbolic dynamics generated by $\mathcal{P}$ in these areas and show that the regular solutions correspond to a Cantor set situated in these areas. We also present a numerical algorithm for verifying these sufficient conditions at the level of “numerical evidence”. This allows us to describe regular solutions of this equation, completely or within some class, by means of symbolic dynamics. We show that regular solutions can be coded by bi-infinite sequences of symbols of some alphabet, completely or within some class. Examples of the application of this technique are given.

The article about problem of consensus as social dialogue basis. Necessary consensus condition is value core as world out-look attitudes community. Author analyses risks of both social community split because of extreme world out-look attitudes pluralism and social uniformity reaching to totalitarian form. Author highlights risk of transformation democracy into ideocracy because of subjection all aspects of civil life to political and ideological agenda.

The effect of inhibitory management is usually underestimated in artificial control systems, using biological analogy. According to our hypothesis, the muscle hypertonus could be effectively compensated via stimulation by bio-plausible patterns. We proposed an approach for the compensatory stimulation device as implementation of previously presented architecture of the neurointerface, where (1) the neuroport is implemented as a DAC and stimulator, (2) neuroterminal is used for neurosimulation of a set of oscillator motifs on one-board computer. In the set of experiments with five volunteers, we measured the efficacy of motor neuron inhibition via the antagonist muscle or nerve stimulation registering muscle force with and without antagonist stimulation. For the agonist activation, we used both voluntary activity and electrical stimulation. In the case of stimulation of both the agonist and the antagonist muscles and nerves, we experimented with delays between muscle stimulation in the range of 0–20 ms. We registered the subjective discomfort rate. We did not identify any significant difference between the antagonist muscle and nerve stimulation in both voluntary activity and electrical stimulation of cases showing agonist activity. We determined the most effective delay between the stimulation of the agonist and the antagonist muscles and nerves as 10–20 ms.

There are two cases when the nonlinear Schrödinger equation with an external complex potential is well known to support continuous families of localized stationary modes: the ‐symmetric potentials and the Wadati potentials. Recently, Kominis et al. have suggested that the continuous families can be also found in complex potentials of the form , where is an arbitrary real and is a real‐valued and bounded differentiable function. Here we study in detail nonlinear stationary modes that emerge in complex potentials of this type (for brevity, we call them W‐dW potentials). First, we assume that the potential is small and employ asymptotic methods to construct a family of nonlinear modes. Our asymptotic procedure stops at the terms of the order, where small characterizes amplitude of the potential. We therefore conjecture that no continuous families of authentic nonlinear modes exist in this case, but “pseudo‐modes” that satisfy the equation up to ‐error can indeed be found in W‐dW potentials. Second, we consider the particular case of a W‐dW potential well of finite depth and support our hypothesis with qualitative and numerical arguments. Third, we simulate the nonlinear dynamics of found pseudo‐modes and observe that, if the amplitude of W‐dW potential is small, then the pseudo‐modes are robust and display persistent oscillations around a certain position predicted by the asymptotic expansion. Finally, we study the authentic stationary modes that do not form a continuous family, but exist as isolated points. Numerical simulations reveal dynamical instability of these solutions.

Quantum cascade lasers (QCL) are widely adopted as prominent and easy-to-use solid-state sources of terahertz radiation. Yet some applications require generation and detection of very sharp and narrow terahertz-range pulses with a specific spectral composition. We have studied time-resolved light-current (L–I) characteristics of multimode THz QCL operated with a fast ramp of the injection current. Detection of THz pulses was carried out using an NbN superconducting hot-electron bolometer with the time constant of the order of 1 ns while the laser bias current was swept during a single driving pulse. A nonmonotonic behavior of the L–I characteristic with several visually separated subpeaks was found. This behavior is associated with the mode competition in THz QCL cavity, which we confirm by L–I measurements with use of an external Fabry–Perot interferometer for a discrete mode selection. We also have demonstrated the possibility to control the L–I shape with suppression of one of the subpeaks by simply adjusting the off-axis parabolic mirror for optimal optical alignment for one of the laser modes. The developed technique paves the way for rapid characterization of pulsed THz QCLs for further studies of the possibilities of using this approach in remote sensing.

Freestanding frequency-selective surfaces with cross-shaped aperture elements are investigated numerically and experimentally. Transmission characteristics of such two-dimensional periodic structures as functions of geometrical sizes are analyzed using the 3D finite element method. These structures find application in modern microwave and terahertz engineering as band-pass metal mesh filters. Utilizing the conjugate gradient method narrowband, 90 GHz filters have been developed and optimized numerically. The results of measurements carried out in the present study agree well with the obtained theoretical data. It is shown that some parameters of such metal mesh filters can be improved by the proper selection of structure periodicity. A single-layer filter with a fractional bandwidth of 5.3% and an insertion loss of − 0.5 dB at the central frequency is demonstrated.

Amorphous ferromagnetic microwires are quite promising for use in various biomedical fields. A microwire in a biocompatible shell can be introduced into soft tissues or into blood vessels to maintain the biofunctioning of magnetic nanoparticles or stem cells with magnetic markers circulating in the blood. The magnetic fields created by the lattices of microwires are characterized by strong spatial gradients and can change over time in a specified manner. Such fields are necessary for the development of various magnetophoretic analytical chips for controlling the kinetics of cells and also for controlled drug delivery. A system of diametrically magnetized microwires is suggested in this paper, which possesses an energy minimum necessary for the stable capture of diamagnetic cells. The suggested dipole system is also promising for the accelerated diffusion transfer of magnetic nanoparticles, which are located in a liquid carrier, due to a gradient magnetic field.

A plane isothermal problem of the internal contact between elastic cylindrical bodies separated by a thin layer of a viscous lubricating fluid under constant load and reverse motion is considered. To determine the deformations of the contacting bodies, solutions of the plane problems of the elasticity theory for a cylinder and a space with a cylindrical cut are used. Extreme cases of low load, high load, small and long periods of reverse motion are considered. The dependences of lubricant layer thickness and pressure on the angular coordinate at different times, as well as the dependence of the eccentricity and the minimum lubricant layer thickness on time are presented. It is shown that the minimum lubricant layer thickness as a function of time exhibits a decrease when braking the cylinder and continues to decrease for some time after a change in the direction of rotation and an increase in speed. It has been established that at the times when the speed is low, under high loads, the gap has narrow spots at the boundaries of the high-pressure area, preventing the lubricant from leaking out of the gap. At a low load and a long period of reverse motion, the maximum pressure in the lubricant layer can increase more than twice.

[Figure not available: see fulltext.] New fluorinated tetraketone derivatives of N-substituted carbazoles were synthesized and tested as ligands for fluorescence immunoassay. The spectral properties of the obtained heterocyclic tetraketones and their Eu(III) complexes were studied. The complexes showed longwave absorption at 360–380 nm, high extinction coefficient values, long lifetime of excited states, and intense luminescence, allowing to consider the use of such lanthanide complexes in immunofluorescence analysis. © 2018 Springer Science+Business Media, LLC, part of Springer Nature

This paper presents the use of a plasmonic sensing transducer on an embedded Mach-Zehnder interferometer (MZI) arm, allowing the sensing transducer to be formed through the stacked layers of the silicon-graphene-gold materials and embedded on a MZI arm with a gripping force to allow it to be used in sensing applications. The transduction process introduces an energy conversion between the input light and the excited electron mobility within the silicon and graphene layers. That way the electron drift velocity within the gold layer can drive the plasmonic wave group velocity induced through the interaction with the graphene layers, and as a consequence the electron mobility in the gold layer increases. The driven electron mobility in the gold layer, caused by the plasmonic waves from graphene in the embedded sensing layers, will affect the electron output mobility, where the relative change in the phase of the light in the silicon can be seen at the output port of the MZI. To optimize the key parameters of such a system, (especially input optical power and dimensions of the gold layer), simulations are performed at various input optical powers and the results are graphically represented. A maximum sensitivity of ~ 2x 10-14 m v-1 s-1 in electron mobility sensing is obtained through these simulations, designed to optimize the performance characteristics of the proposed sensor.

A compact broadband waveguide matched load based on Bragg structures has been developed. It contains alternating nanoscale metal and dielectric layers designed for the frequency range of 140–210 GHz. The voltage standing-wave ratios of less than 1.3 are experimentally obtained in this frequency range.

Frequency response functions of the microwave photonic crystals based on resonant irises with perturbed periodicity (n–i–p–i–n-diode array that serves as a conducting layer) are simulated and experimentally studied. The slot of the iris of the photonic crystal is electrically controlled with the aid of the n–i–p–i–n-diode structure. An electrically controlled modulator and a switch of microwave signal are constructed using the photonic crystal on resonant irises working in the direct and inverse regimes.

Eu(III) chelate-bonded polymer nanoparticles were used as phosphorescent labels to develop a highly sensitive phosphorescence analysis (PHOSPHANTM) for detection of human thyroid stimulating hormone (TSH). The phosphorescence was recorded in a time-resolved mode from microzones (microarrays) that were printed on the bottoms of the wells of standard polystyrene microplates. TSH was detected in paper discs (3.2 mm in diameter) that were punched from capillary blood that was dried on filter paper. The basic analytical and functional characteristics of this new method were similar to those of the commercial reagent kit for TSH detection in dried blood spots from newborns. Both methods made it possible to correctly detect the hormone concentration in the range of 0–250 μIU/mL blood. The analytical sensitivity of the Eu(III) nanoparticle label was 0.46 ± 0.1 μIU/mL (corresponded to approximately 17 fmol/L), which was comparable with the most sensitive assays. The matrix effect was insignificant. The coefficient of the variation of the results (up to 20%) was higher than in the commercial kit. This highly sensitive new test system could be integrated into PHOSPHAN-based multiplex tests to aid in simultaneous detection of markers for several congenital disorders in newborns.