Switching System Research Articles

Coordinated Control Strategy for Drive Mode Switching of Double Rotor In-Wheel Motor Based on MPC and Control Allocation

To overcome the problems existing in the practical application of traditional in-wheel motors used for electric vehicles, an integrated double rotor in-wheel motor was proposed, which can realize three drive modes to meet variable operating condition requirements of the vehicle. The process of switching between different drive modes affects the ride comfort of a vehicle. Taking the mode switching from a single inner motor drive to a dual-motor coupling drive as a research object, a dynamic modeling method of drive mode switching based on the switching system was proposed. According to the critical conditions of each state transition, the switching rules expressed by the segmental constant function were designed. At the engagement stage of electromagnetic clutch II, the torque coordination control strategy based on model predictive control (MPC) and control allocation was proposed. The simulation results show that the proposed strategy can effectively reduce the impact degree of a vehicle and the slipping-friction work of the clutch on the premise of ensuring the fast response of mode switching and the steady increase in vehicle speed. The switching quality of the mode-switching process is effectively improved. In addition, the drive mode switching control of the double rotor in-wheel motor prototype was tested, which proves its ability to operate in multi-drive mode.

Организация самостоятельной работы студентов, направленной на развитие их публикационной деятельности, с использованием проектного и научно-исследовательского методов

The aim of the research is to substantiate the necessity of organising first-year students’ independent work aimed at developing their publication activities when studying Humanities. In the paper, the author describes her own experience of organising the publication activities of the first-year students of the Institute of Telecommunications, training programme 11.03.02 Infocommunication technologies and communication systems (educational programme specialisation “Communication networks and switching systems”) as a form of the students’ independent work as exemplified by teaching “Russian language and the basics of business communication”. The scientific novelty of the research lies in characterising the ways of organising students’ independent work aimed at developing their publication activities based on the joint use of scientific research and project methods; in demonstrating the possibility of combining the educational format involving lectures and seminars and the independent work of the largest possible number of students aimed at developing their publication activities. As a result, the necessity of combining scientific research and project methods in organising students’ independent work aimed at developing their publication activities when studying the discipline “Russian language and the basics of business communication” has been substantiated; the skills and abilities the formation of which is mandatory for each student involved in publication activities have been identified and the competencies that are necessary for students who plan to conduct active publication activities in the future have been identified.

Microscopic insights to spin transport-driven ultrafast magnetization dynamics in a Gd/Fe bilayer.

Laser-induced spin transport is a key ingredient in ultrafast spin dynamics. However, it remains debated to what extent ultrafast magnetization dynamics generates spin currents and vice versa. We use time- and spin-resolved photoemission spectroscopy to study an antiferromagnetically coupled Gd/Fe bilayer, a prototype system for all-optical switching. Spin transport leads to an ultrafast drop of the spin polarization at the Gd surface, demonstrating angular-momentum transfer over several nanometers. Thereby, Fe acts as spin filter, absorbing spin majority but reflecting spin minority electrons. Spin transport from Gd to Fe was corroborated by an ultrafast increase of the Fe spin polarization in a reversed Fe/Gd bilayer. In contrast, for a pure Gd film, spin transport into the tungsten substrate can be neglected, as spin polarization stays constant. Our results suggest that ultrafast spin transport drives the magnetization dynamics in Gd/Fe and reveal microscopic insights into ultrafast spin dynamics.

Neural network-based adaptive controller design for robotic manipulator subject to varying loads and unknown dead-zone

In this article, aiming at handling the trajectory tracking issue of industrial manipulator system (IMS) with modeling uncertainty, varying loads (VL) and unknown dead-zone characteristic, a compensation-based adaptive switching controller synthesis is proposed. In this scheme, the dynamic model of the IMS under VL is regarded as a switched system (SS) with a specified modal set. The nonlinear term related to plant model in each subsystem is approximated by radial basis function neural network (RBFNN) so as to avoid the reliance of the controller on the accurate model, and the unknown dead-zone is estimated and compensated by NN, from which the corresponding NN robust compensation term is developed to eliminate the potential perturbations and estimated errors. The designed controller with switching mechanism effectively solves the problem of degradation of the tracking accuracy caused by VL. Finally, the uniform ultimate boundedness of error signals is analyzed by the average dwell time (ADT) approach, multi-Lyapunov function method and the synthesized adaptive control law, and the effectiveness of the developed scheme is verified by simulation.

A novel observer design for friction estimation

In this paper, we propose a novel adaptive friction estimator for simple mechanical systems with Coulomb friction. We assume that the friction constant is unknown and we propose an adaptive observer for its estimation. We show that under certain conditions the observer structure is asymptotically stable. The proposed observer dynamics has two tuning parameters and essentially behaves as a second-order switching system. These parameters could be utilised to tune some time domain performance measures such as settling time, per cent overshoot. etc., under certain conditions. Lastly, simulations reveal that when the actual friction is not confined to Coulomb friction only, the proposed design improves the position tracking performance, especially when the position controller has low bandwidth.

Event-triggered H∞ robust filtering for nonlinear semi-Markov switching systems

This paper studies the filtering problem for a class of discrete-time semi-Markov switching repeated scalar nonlinear systems with an event-triggered scheme. Considering the limitation of bandwidth, the mode-dependent event-triggered mechanism is introduced to determine whether the currently sampled sensor data is transmitted to the filter, in which the parameters of the event generator depend on the system mode. By means of a constructed time-varying Lyapunov function, the two stages of the systems jump instant and mode residence are analysed, and a linear matrix inequality technique is used to ensure the mean-square stability and performance of the filter error system. Accordingly, the co-design method of the mode-dependent time-varying filter and the event-triggered mechanism is derived for semi-Markov switching systems. Finally, a numerical simulation is given to illustrate the effectiveness and feasibility of the method proposed in this paper.

Distributed event-based H∞ consensus filtering for 2-D T-S fuzzy systems over sensor networks subject to DoS attacks

This paper concentrates on the H∞ consensus filtering issue of a kind of nonlinear two-dimensional (2-D) systems over sensor networks, which are described by the Takagi-Sugeno fuzzy model. With consideration of the limited communication bandwidth and the malicious network attack behavior, a distributed event-triggered mechanism is considered for the sensor network under DoS attacks. Different from the implicit assumption of many previous results that detail information of the non-periodic DoS attacks is available, a switching-like distributed event-triggered mechanism is introduced under the 2-D framework, which could schedule the triggering strategy flexibly in the attack silent or active regions. By means of the switching system analysis method and the discontinuous Lyapunov functions, this paper aims to develop a proper distributed attack-resilient H∞ consensus filter based on the information from the local sensor and its neighbors. A set of sufficient conditions are presented so that the estimation error system can reach exponential stability and meet an expected H∞ performance. Finally, a numerical example is given to demonstrate feasibility of the filter designing method.

Handling mode and polarization in fiber by fs-laser inscribed (de)multiplexer and silicon switch array

The emergence of dynamic optical switching has opened up new perspectives for lightening the ever growing load on the electrical switches and routers, to meet the increasing demand on high-speed and flexible data processing and management in fiber-optic communications. Despite diversity schemes of optical switching in the single-mode regime, multi-mode switching of the hybrid fiber and chip system enabled by photonic integrated circuits, especially for the fiber-chip-fiber system, is still an outstanding challenge. Here, we propose and demonstrate the mode and polarization transmission and switching fiber-chip-fiber system with few-mode fibers (FMFs), including the FMF links for mode- and polarization-division multiplexing data transmission, the femtosecond (fs)-laser inscribed 3-dimensional (3D) photonic lantern silica chip for (de)multiplexing and coupling between FMFs and chip, and the topology-optimized N × N non-blocking 2-dimensional (2D) silicon switch array chip for switching and routing. Using 30-Gbaud quadrature phase-shift keying signals on wavelength-division multiplexing (WDM) channels, the WDM-compatible hybrid mode/polarization transmission, switching and routing system with FMFs, fs-laser inscribed silica (de)multiplexing chip and silicon switch array chip are demonstrated in the experiment with favorable operation performance. The demonstration may open the door for developing robust multi-dimensional optical data processing in fiber-optic communication systems with versatile fibers and chips.

When Reliability is Critical

Innovative PXI switching and simulation systems can sustain the test system throughout a long life. TOM SARFI explains

Тенденция перехода на удаленную работу и рынок труда в условиях цифровизации

Digital technologies are changing modern society. At the same time, the speed and scale of changes are increasing, which makes it necessary for almost all spheres of life to respond objectively to the processes taking place and rebuild them in accordance with new realities. The article examines the results of the impact of digital transformation on the labor market, employment, labor cost efficiency and significant competencies of employees. The author presents the results of the sociological research – a questionnaire survey of self-employed citizens. In the context of the active development of digitalization, the introduction of new technologies, a simplified system for switching to a remote mode of work, caused, among other things, by the COVID-19 coronavirus pandemic, the relevance of the chosen topic is due to the rapid renewal of the labor market and the changeability of in-demand professions, changes in practice and traditional ideas about employment. History and related processes are interdependent. Just as the transition from an agrarian society to an industrial one could not take place only positively or only negatively, so during the transition to a digital society, the influence of a new wave of information technologies radically changes people's lives, on the one hand – simplifying many processes, on the other hand – causing certain difficulties. Therefore, the state of a society based on digitalization cannot be viewed only from the positive or only from the negative side. Digitalization defines systemic risks and carries the threat of total unfreedom.

Real-time environmental radiation monitoring based on locally developed low-cost device and unmanned aerial vehicle

In this study, a low-cost local device based on an Unmanned Aerial Vehicle (UAV) for real-time environmental radiation monitoring is proposed. The device consists of a Geiger-Müller ZP 1200 counter for gamma radiation detection and an appropriate electronic circuit for processing and shaping the detected pulses. The Geiger-Müller detector used is low-cost, insensitive to environmental temperature variations, and can be operated continuously over a long period. Two different methods were performed to calibrate the designed device, namely the use of a programmable nuclear pulse generator for electronic calibration and a Cs-137 gamma-ray calibration source. A long flight time UAV is developed locally with suitable characteristics and adapted to carry the radiation detection device. The designed UAV mainly consists of a multi-flight controller having an intelligent switching system associated with a GPS Module for accurate position-keeping and four heavy lift motors. The use of UAVs has the advantage that it allows measurements to be taken over large areas, even those that are difficult to access, and avoids exposing people to radiation. The flight measurement tests were carried out in the urban area of Yaoundé-Cameroon, at an altitude of 15 to 100 meters with a sweeping speed of about 20 km/h for 36 days from January 01, 2023, to February 06, 2023. The tests showed that the concentrations collected varied between 0.00697 μSv/h and 0.8706 μSv/h, of which 85.71% of data have a concentration below the threshold (0.3 μSv/h) and 14.29% above this threshold. These tests confirm that the developed radiation detection system works properly and is suitable for environmental radiation protection and nuclear safety activities.

Distributed [formula omitted] filtering of replay attacks over sensor networks

A distributed H∞ filtering issue is addressed in this paper for discrete-time nonlinear systems in the face of replay attacks over sensor networks, where an indicator variable is introduced to describe whether a replay attack is launched by the adversaries. First, an interesting pattern dependent on three parameters including a time-varying one is established to account for the temporal behavior of malicious attacks. Then, taking advantage of such a model, the resulting filter dynamic is transformed into a switching system with a subsystem with time-varying delays. By means of the famous switching system theory, a sufficient condition guaranteeing the H∞ performance is derived to disclose the tolerant attack condition, that is, the attack-active duration and proportion. In addition, the applicable filter gains are achieved with the aid of the solutions of matrix inequalities. Finally, an example is purposively given to adequately illustrate the availability of the developed secure filtering strategy.

Stochastic Linear-Quadratic Optimal Control Problems with Random Coefficients and Markovian Regime Switching System

Stochastic Linear-Quadratic Optimal Control Problems with Random Coefficients and Markovian Regime Switching System

Event-Triggered Extended Dissipativity Fuzzy Filter Design for Nonlinear Markovian Switching Systems against Deception Attacks

This article is concerned with the adaptive-event-triggered filtering problem as it relates to a class of nonlinear discrete-time systems characterized by interval Type-2 fuzzy models. The system under investigation is susceptible to Markovian switching and deception attacks. It is proposed to implement an improved event-triggering mechanism to reduce the unnecessary signal transmissions on the communication channel and formulate the extended dissipativity specification to quantify the transient dynamics of filtering errors. By resorting to the linear matrix inequality approach and using the information on upper and lower membership functions, stochastic analysis establishes sufficient conditions for the existence of the desired filter, ensuring the mean-squared stability and extended dissipativity of the augmented filtering system. Further, an optimization-based algorithm (PSO) is proposed for computing filter gains at an optimal level of performance. The developed scheme was finally tested through experimental numerical illustrations based on a single-link robot arm and a lower limbs system.

A computational model of prefrontal and striatal interactions in perceptual category learning

Work on multiple-system theories of cognition mostly focused on the systems themselves, while limited work has been devoted to understanding the interactions between systems. Generally, multiple-system theories include a model-based decision system supported by the prefrontal cortex and a model-free decision system supported by the striatum. Here we propose a neurobiological model to describe the interactions between model-based and model-free decision systems in category learning. The proposed model used spiking neurons to simulate activity of the hyperdirect pathway of the basal ganglia. The hyperdirect pathway acts as a gate for the response signal from the model-free system located in the striatum. We propose that the model-free system’s response is inhibited when the model-based system is in control of the response. The new model was used to simulate published data from young adults, people with Parkinson’s disease, and aged-matched older adults. The simulation results further suggest that system-switching ability may be related to individual differences in executive function. A new behavioral experiment tested this model prediction. The results show that an updating score predicts the ability to switch system in a categorization task. The article concludes with new model predictions and implications of the results for research on system interactions.

Contactless Switching System Based on Gesture Recognition

ith the downgrading of COVID-19, the public affairs we contact in our daily life still cause potential indirect transmission risks, so we should pay more Gesture recognition is used to safely and quickly control these objects, so as to avoid them becoming the "hotbed" of virus transmission, reduce the chance of virus infection, and ensure the safety of public health. Gesture recognition is used to safely and quickly control these objects, so as to avoid them becoming the "hotbed " of virus transmission, reduce the chance of virus infection, and ensure the safety of users. Based on this, we propose to develop a contactless switching system using low cost and high reliability infrared gesture recognition.

A comparative study of data-driven electro-thermal models for reconfigurable lithium-ion batteries in real-time applications

Reconfigurable battery systems can change the cell topology, which allows novel applications that are not possible with conventional battery systems. However, reconfiguration complicates monitoring of the individual cell state since greater variances in temperature and SOC are introduced. Especially critical for a safe operation and adequate performance is the thermal behavior, which needs to be determined for every single cell in real-time. In this work, four different reduced-order lumped models and four artificial neural network models are compared in a surrogate modeling approach for the practical application in a reconfigurable battery system. The comparison includes the representation of serial and serial–parallel topologies. Furthermore, different coupling variants of single cell models are investigated in order to find the best representation of the physical model of a reconfigurable battery systems in an automotive application. While a separate observation of individual cells in switching systems is shown to be no longer sufficient, good results are already evident with simple models and adequate coupling approaches. The data-driven surrogate approaches achieved errors as low as 0.1 K while at the same time reducing the computational effort drastically compared to a physics-based model.

Broadband polarization/mode insensitive 3-dB optical coupler for silicon photonic switches.

In this work, we experimentally demonstrate a four-mode polarization/mode insensitive 3-dB coupler based on an adiabatic coupler. The proposed design works for the first two transverse electric (TE) modes and the first two transverse magnetic (TM) modes. Over an optical bandwidth of 70 nm (1500 nm to 1570 nm), the coupler exhibits at most 0.7 dB insertion loss with a maximum crosstalk of -15.7 dB and a power imbalance not worse than 0.9 dB. A multimode photonic switch matrix using this optical coupler is proposed simultaneously exploiting wavelength division multiplexing (WDM), polarization division multiplexing (PDM), and mode division multiplexing (MDM). Based on the coupler experimental measurements, the switching system loss is estimated to be 10.6 dB with crosstalk limited by the MDM (de)multiplexing circuit.

Artificial Action Potential and Ionic Power Device Inspired by Ion Channels and Excitable Cell.

In vivo, the membrane potential of the excitable cell working by ion gradients plays a significant role in bioelectricity generation and nervous system operation. Conventional bioinspired power systems generally have adopted ion gradients, but overlook the functions of ion channels and Donnan effect to generate efficient ion flow in the cell. Here, cell-inspired ionic power device implementing the Donnan effect using multi-ions and monovalent ion exchange membranes as artificial ion channels is realized. Different ion-rich electrolytes on either side of the selective membrane generate the ion gradient potentials with high ionic currents and reduce the osmotic imbalance of the membrane. Based on this device, the artificial neuronal signaling is presented by the mechanical switching system of the ion selectivity like mechanosensitive ion channels in a sensory neuron. Compared with reverse electrodialysis, which requires a low concentration, a high-power device with ten times the current and 8.5 times the power density is fabricated. This device activates grown muscle cells by increasing power through serial connection like an electric eel, and shows the possibility of an ion-based artificial nervous system.

A multifunction flow channel switching module for multi-column capillary gas chromatography using silicon pneumatic microvalves

Decades ago, multi-column GC was developed for separating analytes which cannot be separated with a single column by switching the flow channels and introducing them into multiple columns. Formerly, a channel switching system consisted of stainless-tube-type packed columns and multi-port switching valves which were connected by stainless-steel pipes. These systems utilizing packed columns are still widely used today, mainly for gas analysis, especially for refinery gas analysis and natural gas analysis related to oil refining. However, there have been no new development updates in terms of hardware for decades. Since multi-port switching valves are used, there are problems such as the high frequency of valve replacements due to wear of seals, high running costs as well as long downtimes. In recent years, a heart-cutting multidimensional capillary GC using pressure switching devices such as the Deans switch has been put into practical use. Compared to the switching valves, the pressure switching devices have no wearing parts and are maintenance-free. Multi-dimensional capillary GC using the pressure-switching method cannot be applied to the analysis of low-boiling-point gasses because the retention capacity of the capillary column is low and the column inlet pressure is far from the optimum value for switching. Because of this another related factors, it has not been able to completely replace the traditional methods. In this study, an ON/OFF type silicon pneumatic microvalve was designed and fabricated by semiconductor manufacturing technology, and a flow channel switching module was developed by mounting microvalves on a metallic channel plate which is made by diffusion bonding. The flow channel switching module using silicon pneumatic microvalves has a heat resistance of up to 310 °C, can withstand pressures up to 1.5 MPA or more, and a durability that can withstand over 2 million opening and closing operations. In addition, the reproducibility of the gas sample analysis showed good reproducibility values of RSD 0.1% or less for peak areas and RSD 0.01 to 0.04% for retention time. Flow path switching without the use of pressure switching simplifies method development in several ways. For instance, by incorporating the use of valves that can be opened and closed independently, it was possible to integrate several methods such as heart cut, precut, column switching, and backflushing flow path layouts.