Switching Logic Research Articles

Current-Limiting Soft Starting Method for a High-Voltage and High-Power Motor

Focusing on the starting problems of a high-voltage and high-power motor, such as large starting current, low power factor, waste of resources, and lack of harmonic control, this paper proposes a current-limiting soft starting method for a high-voltage and high-power motor. The method integrates functions like autotransformer voltage reduction–current limiting starting, magnetron voltage regulation–current limiting starting, and reactive power compensation during starting, and then the power filtering subsystem is turned on to filter out harmonics in power system as the starting process terminates. According to the current-limiting starting characteristic curve, the topological structure of the integrated device is established and then the functional logic switching strategy is put forward. Afterwards, the mechanisms of current-limiting starting, reactive compensation and dynamic harmonic filtering are analyzed, and the simulation and experimental evaluation are completed. In particular, the direct starting and the current-limiting are performed by developing a simulation system. In addition, a 10 kV/19,000 kW fan-loaded motor of a steel plant is chosen as the subject to verify the performance of the current-limiting soft starting method. As shown by the experimental results, the motor’s starting current is about 2 times that of its rated current, the power factor is raised to over 0.9 after the reactive power compensation, and the harmonic filter can effectively eliminate current harmonics and reduce the total harmonic distortion (THD) of supply currents.

Asymmetric bipolar switch device for electrochemical processes

New strategies for the intensification of industrial electromembrane processes are needed, especially to reduce equipment size and operational costs. To intensify those processes and to decrease fouling and scale occurrence in such systems, we propose operation with very short asymmetric pulses (order of microseconds) of alternating polarity. Hence, a custom made Asymmetric Bipolar Switch was designed and built, operating with pulse widths in the 10-5-10-2 s range. Compared to traditional systems, we demonstrate the possibility of applying pulses with high intensities, up to three times higher than normal operation, using a frequency range between 0 (continuous operation) and 102 Hz. The proposed device was coupled to an electrodialysis cell for desalting a brine solution. When switching in desalination, a Back Electrochemical Force was identified, which could affect the integrity of the electronic systems due to spikes of reverse voltage. Hence, mitigation strategies were applied by changing the switching logic and incorporating new elements in the circuitry, similar to those in breaking methods in electrical motors. While desalting in electrodialysis, the experiments showed a limited power loss, up to 0.6% of the total power applied, attributed mainly to electrical disturbance (conduction and switching losses in the electronic components were minor at this scale). No significant variation in the desalination performance was observed at low current densities. The designed Asymmetric Bipolar Switch opens new possibilities for the operation with electromembranes and other electrochemical processes.

On a Robust, Sensitive Cell-Free Method for Pseudomonas Sensing and Quantification in Microfluidic Templated Hydrogels.

Through the use of droplet microfluidics to integrate cell-free activity into inert hydrogel beads, we have developed a platform that can perform biologically relevant functions without the need for cells. Specifically, cell-free lysates serve a utility in performing cellular functions and providing biologically relevant metabolic products without requiring the optimal biological conditions for cell growth and proliferation. By teasing out specific biological components that enable transcription and translation to occur, these cell-like functions can be reconstituted in vitro without requiring the entire cell and milieu of cellular organelles. This enables the optimization of synthetic biological circuits, either by concentration or logic switches, simply through the addition or removal of genetic components (plasmids, inducers, or repressors) of regulatory elements. Here, we demonstrate an application of cell-free processes that is robust and portable, independent of a substrate, to apply for sensing and reporting functions of a quorum-sensing molecule N-3-oxododecanoyl homoserine lactone (3OC12HSL) found crucial for pathological Pseudomonas aeruginosa infection. We develop an agarose bead platform that is easily adaptable and simply programmable to fit a variety of biological and chemical sensing applications for the utility of ease of delivery and activation in remote environments—even in conditions with very little hydration.

An efficient voltage to delay conversion method for DCVSL cells and its application in high speed all‐digital time‐based quantization

SummaryTranslating the analog input voltage to delay of delay cells is a necessity for realizing digital time‐based quantization. Usually, this conversion is done through additional elements, imposing extra power and area. This paper proposes a voltage to delay conversion method for cross‐coupled differential cascode voltage switch logic (DCVSL) cells, without adding any extra elements to their basic structures. Cross‐coupled delay cells are superior to conventional CMOS inverters in terms of lower power consumption, propagation delay, and area. However, controlling their delay is a demanding task due to their asynchronous charging and discharging. The key features of the proposed method are (a) controlling the delay of DCVSL cells just by see‐saw changing of PMOS transistors source voltages; (b) reducing the propagation delays of DCVSL cells by simultaneously accelerating the charging and discharging processes; (c) reducing the power consumption by decreasing both the switching time and short‐circuit current; (d) employing the proposed voltage to delay conversion method to develop a low power, small area, all‐digital time‐based analog to digital converter (ADC). The proposed 4‐bit ADC, implemented in TSMC 65‐nm CMOS technology, consumes 0.37 mW at conversion speed of 2 GHz with SNDR 20.9 dB and SFDR 30.2 dB, and occupies an active area of 0.0029 mm2.

Guaranteeing Global Asymptotic Stability and Prescribed Transient and Steady-State Attributes via Uniting Control

In this paper, we unite a controller designed via the prescribed performance control methodology, with a given, in a black box form, locally asymptotically stabilizing control scheme that encapsulates any prior knowledge related to the controlled system. In that perspective, we devise a hybrid control strategy, to guarantee the exponential convergence of the output tracking error to a prespecified neighborhood of the origin, with a predefined minimum convergence rate. Furthermore, the origin of the uncertain nonlinear error system is rendered globally asymptotically stable, while preserving the boundedness of all signals in the closed loop. Attention is paid to maintain the complexity of the resulted control solution at low levels. The developed switching logic prevents the appearance of Zeno behavior and guarantees the termination of switchings in finite time. Illustrative simulations clarify and verify the approach.

Optimal Placement of FACTs Devices in Iraqi National Super Grid System (INSGS) Using HLSI

Many of the power cuts in the electricity system in the last decade indicate that there is much work to be done to address the voltage instability and subsequent collapse. This study presents a method to find and select the optimum location of FACTs device using the hybrid line stability index (HLSI) that is appropriate for the prediction voltage collapse in power system networks. Such the HLSI was obtained by deriving expressions basics equivalent Line Stability Index (Lmn), and Fast Voltage Stability Index (FVSI) and mix theirs through a switch logic based on the voltage angle difference Where indicate the nearness voltage collapse. The HLSI has tested in Iraqi National Super Grid System (INSGS) it gives the same results as the other indicators (Lmn & FVSI). For the base state, INSGS was found to be stable with all the three indicators have approximately equal values least than 1 for all lines. The contingency state detects that ranks of bus 24 the weakest bus in the system with the lower maximum allowable reactive load of (490.371 Mvar) and the line critical concerning bus 24, the line connecting bus 20 to bus 24. The values the three indicators, Lmn, FVSI, and HSLI, approximately equal, increasing the accuracy of HLSI.

Electrically Controlled Logical Switch Based on a Step Yttrium–Iron Garnet Waveguide and a Piezoelectric Actuator

We have demonstrated the possibility of functioning a device based on a spin-wave waveguide containing two channels with different ferrite film thicknesses as a logical switch. For switching states, we have used the dependence of interference type (constructive or destructive) at the output converter common for two channels on the waveguide strain under action of the electrically controlled actuator.

Switching Logic-Based Nonlinear Feedback Control of Offshore Ship-Mounted Tower Cranes: A Disturbance Observer-Based Approach

We propose, in this paper, an observer-based nonlinear feedback controller for four degrees of freedom (4-DOF) offshore ship-mounted tower cranes, which includes a robust-type term to address the observation uncertainty, and a switching logic tuning mechanism to update the involved unknown parameter. As a typical nonlinear underactuated mechatronic system, unlike the land-fixed tower cranes, an offshore ship-mounted tower crane also suffers from persistent disturbances caused by sea waves or currents, which leads to many difficulties and challenges in the controller design of such systems. Existing offshore crane control methods require either linearizations or approximations when performing analysis; moreover, most of them are only applicable for simplified 2-DOF crane models, and the ranges of system state errors cannot be guaranteed during the overall process. Motivated by these facts, to achieve simultaneous accurate jib/trolley positioning and fast payload swings suppression against complex unknown external disturbances, in particular, a disturbance observer is first designed in this paper, based on which a novel nonlinear switching logic-based control scheme for offshore cranes with jib rotation and horizontal transportation is proposed. As far as we know, the proposed method yields the first observer-based feedback closed-loop control without simplification operations to the original 4-DOF offshore tower crane dynamics and achieves the first asymptotic stability of the closed-loop system’s equilibrium point for offshore cranes. To support the theoretical derivation, the corresponding stability analysis of the closed-loop system’s equilibrium point is implemented by Lyapunov techniques. Numerous simulation and hardware experimental results are presented to demonstrate the superior performance of the proposed method. Note to Practitioners —This paper is motivated by the issue of controlling a four- degree-of-freedom (4-DOF) offshore ship-mounted tower crane system under the effects of unknown external disturbances. In practical applications, the persistent disturbances caused by sea waves or currents can always happen and make the offshore crane operation very challenging. Moreover, it brings more difficulties in the controller design for such a system due to its nonlinear underactuated property. Existing control approaches for offshore cranes are developed based upon linearized or oversimplified crane models or require exact model knowledge, and they may not work well in the presence of harsh sea conditions. Toward this end, this paper suggests a new control approach for 4-DOF offshore tower cranes suffering from sea wave effects to achieve a satisfactory performance. The asymptotic stability of the closed-loop system’s equilibrium point is derived, implying that the accurate jib/trolley positioning and fast payload swings suppression against complex unknown external disturbances are achieved simultaneously. Preliminary physical experiments implemented on a self-built offshore tower crane hardware test bed verify the effectiveness and the robustness of the proposed observer-based control method. In the future research, we will apply the suggested control approach to industrial offshore crane systems to improve their working efficiency.

A self-switching multi-strategic pedagogical agent

Multi-Strategic Pedagogical Systems (MSPSs) integrate multiple Pedagogical Strategies (PSs) and a Switching Logic (SL). They trigger the PS appropriate regarding the Student State (StS). However, the hard-coding and the monolithic integration of multiple PSs and a SL highly increase the complexity of the MSPSs. To overcome this deficiency, we recourse to the Self-* and the Component-Based Agents design approaches to engineer a Self-Switching Multi-Strategic Pedagogical Agent (Self-S MSPA). It is designed as two distinct interacting Manager (MrSS) and Managed (MdSS) Sub-Systems. The MdSS implements the PSs. The MrSS implements the SL in the form of an Autonomic Control Loop (ACL) to (re)configure the MdSS. To experiment the usefulness of the proposed model, a framework is constructed using SAFRAN.

A Variation-Aware Robust Gated Flip-Flop for Power-Constrained FSM Application

Advancement in technology towards mobile computing and communication demands longer battery life, which mandates the low power design methodologies. In this paper, we have presented a novel low-power 8T flip-flop (FF) architecture, which has outsmarted the existing well-known dynamic, semi-dynamic and explicit pulsed flip-flops in terms of power and delay. The major ingredient of this architecture is a voltage keeper, which is incorporated to achieve reliable logic switching at the propagating nodes of the design. However, we have also come up with two new approaches of gated clock generation based on transmission gate (TG) and pass transistor logic (PTL) as a modification of LECTOR-based gating. These gating logics have proved themselves to be competent enough to reduce both the static and dynamic power dissipations and hence are employed to the proposed flip-flop to achieve further reduction in power than its nongated correspondent. The performance of this proposed gated flip-flop is tested in a finite state machine with its application in low-power serial adder design. All the simulations are carried out using 65-nm and 90-nm CMOS technologies with a power supply of 1.1[Formula: see text]V at 6.6[Formula: see text]GHz clock frequency. The gated FF saves 52.12%, 6.36% and 28.18% average power-using LECTOR, TG and PTLs, respectively, with respect to its nongated counterpart in 65-nm technology. The performance metrics of gated and nongated proposed designs are affirmed in the environment of commercialized CMOS foundry.

Hybrid Flocking Control Algorithm for Fixed-Wing Aircraft

This paper investigates the fixed-wing aircraft flocking problem with nonholonomic constraints, speed limits, conflict avoidance, and the efficient use of airspace taken into account. It is challenging to simultaneously address all of these issues with less restrictive requirements on the initial configuration of the aircraft, and yet, there are few theoretically rigorous works explicitly considering the fixed-wing aircraft flocking problem. Proposed here is a hybrid flocking control algorithm with three modes of decentralized flocking control protocol and a state-dependent switching logic. The three modes of control protocol are designed using artificial potential fields to address the collective flight behavior subject to the constraints of fixed-wing aircraft. The mode switching logic is designed based on the invariance principle, such that the desired convergence properties are guaranteed to be achieved. In addition, the proposed hybrid flocking control algorithm avoids undesirable fast mode switching.

Gate-tunable polariton superlens in 2D/3D heterostructures

Polaritons in polar-dielectrics and van der Waals (vdW) materials provide a channel for strong photon confinement. Precise control of their propagation could lead to deep sub-wavelength photonic devices. Here, we report negative refraction of hybrid surface phonon-hyperbolic polaritons (SPh-HP) at the interface of two-dimensional (2D) van der Waals layers such as hexagonal boron nitride (h-BN) and 3D semiconductors such as germanium and silicon carbide. These hybrid polariton modes have naturally negative group velocity arising from the intrinsic Type-I hyperbolicity of h-BN resulting in negative refraction at interfaces with positive group velocity. Using this phenomenon, we demonstrate an in-plane superlensing effect in an ultrathin (~10 nm) slab with spatial confinement of long Infrared wavelengths to below 200 nm focal spots. We further demonstrate electrical tunability of the superlens by controlling the Fermi level of graphene, thereby offering potential for miniaturized infrared to THz modulators, photodetectors as well as logic switches.

MiSAL - A minimal quality representation switch logic for adaptive streaming

Quality of Experience is affected by many parameters. For this reason, client-side adaptation logic algorithms often adopt the strategy of optimizing a subset of parameters in the hope of improving the overall QoE. However, as shown here, this approach ends up degrading parameters that are crucial to good Quality of Experience. To resolve this conundrum, we present a new approach for improved Quality of Experience dubbed: Minimal Switch AL (MiSAL). This algorithm substantially reduces the number of quality level switches by monitoring the client buffer level and carefully estimating the channel bandwidth and the Round Trip Time. A comparison of MiSAL against leading ALs demonstrates that this approach successfully in optimizes several important parameters that affect Quality of Experience without negatively affecting other parameters. It is shown that MiSAL can provide a close to optimal QoE under many different network conditions.

Employing graphene acoustoelectric switch by dual surface acoustic wave transducers

We implement a logic switch by using a graphene acoustoelectric transducer at room temperature. We operate two pairs of inter-digital transducers (IDTs) to launch surface acoustic waves (SAWs) on a LiNbO3 substrate and utilize graphene as a channel material to sustain acoustoelectric current Iae induced by SAWs. By cooperatively tuning the input power on the IDTs, we can manipulate the propagation direction of Iae such that the measured Iae can be deliberately controlled to be positive, negative, or even zero. We define the zero-crossing Iae as {I}_{ae}^{off}, and then demonstrate that Iae can be switched with a ratio {I}_{ae}^{on}/{I}_{ae}^{off}, sim ,{10}^{4} at a rate up to few tens kHz. Our device with an accessible operation scheme provides a means to convert incoming acoustic waves modulated by digitized data sequence onto electric signals with frequency band suitable for digital audio modulation. Consequently, it could potentially open a route for developing graphene-based logic devices in large-scale integration electronics.

LQ Secure Control for Cyber-Physical Systems Against Sparse Sensor and Actuator Attacks

This paper investigates the problem of secure control for cyber-physical systems (CPSs) under sensor and actuator attacks. The attacks are assumed to be sparse but arbitrary. The strong detectability under the sparse attacks is characterized by computing the rank of the so-called structural matrix pencil. An adaptive hybrid control strategy is proposed by automatically excluding the tampered measurement and input data. First, a hybrid system consisting of all possible combinations of models is implemented. Then, combining classical linear quadratic control theory, an adaptive switching logic is designed to online locate the proper system mode by observing the optimal performance index. As a result, the closed-loop system is ensured to be asymptotically stable in the presence of the attacks, while the performance loss can be mitigated. Also, the performance degradation under attacks is also analyzed quantificationally based on the quadratic cost function. Simulation results on an aircraft system are given to substantiate the proposed method.

Implementation of all-optical active low/high tri-state buffer logic using the micro-ring resonator structures

Implementation of high-speed switching activity in the all-optical domain is one of the required necessities for modern high-speed technology and secured communication. The paper includes the interesting method describing micro-ring resonator structures as switching logic, exploring it to implement the active low tri-state buffer in the all-optical domain structures. The paper shows the switching activity of micro-ring resonator structures along with the corresponding graphs are discussed, including what happens when enabling the effective active high/low all optical tri-state buffer logic functionality. The application and advantage of tri-state buffer logic in the all-optical domain are explained.

Fatigue load mitigation in wind turbine using a novel anticipatory predictive control strategy

Wind energy has become a recent evolving source of renewable energy which needs an extensive exploration. The increased configuration of wind turbine instantaneously increases the structural loading of wind turbine components. The prolonged loading on structural components imposes a great impact on the lifetime of the wind turbine and reduces the feasibility of thinner rotor blade. These economical detriments due to the structural damage of turbine are dealt effectively by proposing an anticipatory preview-based control strategy for individual pitching of blades. The proposed multiple point model predictive controller with fuzzy logic switching, exploits the preview wind measurement from the light detection and ranging system which predicts the wind speed in advance. The utmost objective of the proposed controller is its optimized individual blade pitching to reduce the fatigue loads on the wind turbine components using the preview wind data. The blade root bending moment of individual blades and the tower fore-aft deflection which are chosen as the parameters of fatigue stress to be analyzed and controlled. The National Renewable Energy Laboratory’s Fatigue, Aerodynamics, Structures and Turbulence 5 MW baseline onshore wind turbine is used for validating the proposed controller in MATLAB simulation. The non-linear wind field is simulated using the TurbSim software, and the short-term and lifetime damage equivalent loads of the wind turbine for the simulated wind field is analyzed using the MLife software of the National Renewable Energy Laboratory. The proposed controller is compared with the typical model predictive controller and linear quadratic-based controller.

Guaranteeing Disturbance Rejection and Control Signal Continuity for the Saturated Super-Twisting Algorithm

The saturated super-twisting algorithm is a second order sliding-mode control law for robust control in the presence of a bounded control input. Its implementation is based on a switching logic and the resulting control signal typically exhibits a single jump discontinuity. This contribution presents novel stability conditions that allow for tuning the algorithm such that perturbation amplitudes up to the control input bound are rejected with a continuous control signal. A simplified control law is furthermore proposed, which is equivalent to the original algorithm while being easier to implement.

Robust tracking control of aero-engine rotor speed based on switched LPV model

Thrust control in aero-engines is achieved indirectly due to the lack of thrust sensing technologies. A related variable must be chosen for the control, typically high or low pressure rotor speeds. In this paper, an H∞ controller is designed for the rotor speed tracking in aero-engines. First, a small deviation linear model at steady state is obtained from the experimental data. Then, sets of small-deviation linear models are used to construct a linear parameter-varying (LPV) model with gain-scheduled parameters that capture the nonlinearity of the aero-engine dynamics. The LPV model is then converted to a switched convex polytopic form with hysteresis switching logic. Next, a theoretical sufficiency criterion is provided to guarantee H∞ performance based on linear matrix inequalities (LMIs). Relevant theoretical results are applied to prove stability when switching between subsystems. Simulation results are given to show the validity of the proposed design method, where the proposed the strategy with hysteresis switching logic can reduce the computational cost and avoid false switching due to disturbances.

Control of dark and anti-dark solitons in the (2+1)-dimensional coupled nonlinear Schrödinger equations with perturbed dispersion and nonlinearity in a nonlinear optical system

In this paper, we investigate the (2+1)-dimensional coupled nonlinear Schrodinger equations with perturbed dispersion and nonlinearity, which govern the transverse effects in a nonlinear optical system. Using symbolic calculation, the vector one- and two-soliton solutions are obtained via the Hirota method. By choosing the perturbation $$\alpha (t)$$ of the dispersion rate of soliton transmission as different functions, we observe different dark and anti-dark soliton structures. Among other, the parabolic dark soliton, m-shaped and w-shaped anti-dark solitons, two kinds of s-shaped anti-dark solitons with different curvatures and an anti-dark soliton with a peak are displayed. Moreover, the effects of other free parameters on the phase shift and pulse width, and collision of solitons are discussed. These results are of potential significance for the study of ultrashort pulse lasers and optical logic switches.