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Limit checking is very simple and intuitive method that can be applied for fault detection. Concept and variants of limit checking are briefly reviewed in this paper. This includes limit checking of absolute values, trend checking, fixed and adaptive thresholds, use of hysteresis and change detection.

Control problem of systems actuated by the smart material based actuators are quite challenging, because of its intrinsic hysteresis nonlinear behaviors. This paper deals with such systems preceded with unknown hysteresis actuators. When the actuator with unknown hysteresis is cascaded with the uncertain dynamic system, the output of the actuators is also not measurable. Besides, such systems usually suffer from the disturbances. In this paper, the Prandtl-Ishlinskii (PI) hysteresis model is analyzed. Utilizing the properties raised, the fusion of PI model and Adaptive Robust Control (ARC) approach is provided. The proposed controller is able to deal with actuators with unknown hysteresis, uncertain system dynamics. Also, disturbances are also taken into consideration for such systems. The stability of the closed-loop system has been guaranteed and the simulation is provided to demonstrate the performance of the controller developed.

This paper addresses the problem of adaptive compensation event-triggered control for uncertain nonlinear systems with input hysteresis. The communication resources cannot be saved effectively for the considered systems, as traditional event-triggered mechanisms do not consider input hysteresis with nonlinear gain. In a network control system, how to simultaneously overcome the problem of input hysteresis and save communication resources remains a challenge. In this paper, an extended fuzzy approximation method is proposed to estimate uncertain items for control design. The method considers the time-varying error of the approximation instead of viewing the error as a bounded constant. Furthermore, in combination with the extended fuzzy approximation method, an adaptive event-triggered compensation control method for uncertain nonlinear systems with input hysteresis is designed. Under the proposed event-triggered mechanism, the control method can effectively compensate for the input hysteresis and simultaneously save communication resources. Finally, this method is verified through two simulation experiments that the occupation of communication source has been reduced and the stability of the considered system can be guaranteed effectively.

In this paper, an adaptive iterative learning control scheme is propsed for a class of nonparametric systems with hysteresis input described by Bouc-Wen model. First, based on analyzing the property of Bouc-Wen model, the adaptive learning controller is designed by using Lyapunov synthesis. In the control design, the nonparametric uncertainty and hysteresis nonlinearity is compensated by robust strategy and iterative learning strategy together, according to the property of Bouc-Wen model. As the iteration increases, the system state can track its reference signal accurately over the whole period. Numerical results demonstrate the effectiveness of the adaptive learning control scheme.

The problem of time delay control (TDC) for a uncertain linear systems with input hysteresis is studied in this paper. To mitigate the effectiveness of input hysteresis, a controller based on TDC is proposed. Particularly, the time delay estimation (TDE) is used to estimate the uncertainty and the unknown nonlinear part of the hysteresis. Then, a time delay controller is designed to obtain high performance without modeling the hysteresis. Finally, compared with an adaptive sliding mode controller, the simulation results show the effectiveness and superiority of the proposed controller.

Discussion on the hysteresis control with double synchronization (HDS-control) represents one of the most illustrative examples of striking influence of the bifurcation theory on the comprehension of regulator peculiarities. On the one hand, the HDS-regulator provides efficiency, simplicity and stability of energy conversion at the expense of the successful combination of advantages of both hysteresis control and pulse control. On the other hand, it turned out, that the HDS-operating regime can not be explained completely from the control theory only. Simplistically, any system under the HDS-control will inevitably demonstrate nonlinear dynamics; and HDS-operating regime represents various alternations between several operating processes (so-called elementary processes) with equal frequency (the synchronization frequency) and different orders of structural changes caused by four synchronizing surfaces. From the bifurcation theory, the following nontrivial points appear: how many elementary processes and how to treat alternations? Perhaps, due to these circumstances HDS-regulators are practically ignored in industrial applications after 2009 (after quarter-of-a-century accident-free usage of HDS-regulators in the control system of the high-speed railway train ER200 exploited on the railway line Moscow - St. Petersburg from year 1984, Russia). Revival interest in the HDS-dynamics nonlinear picture was initiated by the novel results when accents were shifted from the desired operating performance towards potential nonlinear phenomena. Here we comment briefly HDS-control basis and discuss these accents with attracting both computer simulations and experimental tests.

In this paper, by incorporating implicit inverse technique into a dynamic surface based adaptive control design framework, we have developed a robust adaptive dynamic surface implicit inverse control for a class of nonlinear systems with unknown Prandtl-Ishilinskii (PI) hysteresis. Our development one hand is to eliminate the problem of “explosion of complexity” inherent in the backstepping method, on the other hand, instead of constructing the hysteresis inverse model to eliminate the hysteresis in the system, we eliminate the hysteresis by finding the optimal value of the PI performance index. And solve the difficulty of solving the hysteresis model by optimizing the method. In addition, the stability analysis shows that the system is semi-globally consistent and ultimately bounded, and the effectiveness of the proposed method is proved by simulation results.

The use of the tendon-sheath mechanism (TSM) is common in flexible surgery robots, because it can flexibly work in limited spaces and provides efficient power transmission. However, hysteresis from nonlinearities such as friction and backlash poses a challenge in controlling precise motion in the surgical instrument. Moreover, this hysteresis is also affected by changes in the various configurations of sheath which limits traditional model-based compensation approaches. Recently, feedback approach using an endoscopic camera is presented, but they use markers which are not appropriate for applying to a real surgical instruments. In this paper, a novel hysteresis compensator with learning-based pose estimation is proposed. Unlike previous studies, the proposed compensator can reduce hysteresis of the surgical instrument in various sheath configurations without using markers. In order to estimate an actual angle of the surgical instrument’s joint, we employ the learning-based pose estimation using a siamese convolutional neural network (SCNN). The proposed compensator reduces hysteresis by partially controlling the position command, similar to the instinctive adjustments that physicians make with their visual feedback. To validate the proposed method, a testbed was constructed considering several requirements of flexible surgery robots. As a result, the results show the proposed method reduces hysteresis to less than 10°, for various configurations of sheath. In addition, we confirmed that the learning-based pose estimation is sufficient to apply to the proposed compensator for reducing hysteresis in real-time.

The paper is devoted to one of directions of scalable physical experiments, where it is supposed that there is a mathematical model in the form of a dynamical system to describe conceptually the physical phenomena which are surely observed but beyond-the-limits outlined by the traditional theories. In particular, we focus on the phenomenon of the interannual temperature variability in local climate dynamics known over the period of meteorological observations, and make studies with the assumption that this phenomenon is excused by the regularities which are typical for the specific dynamical system with a variable structure. Namely, we consider so-called HDS-hypothesis, in accordance to which this variability follows from the competing amplitude quantization (limited by the temperature Hysteresis) and time quantization (the Double Synchronization); and this specific is described by the mathematical model of the hysteresis regulator with double synchronization (so-called HDS-model). So, the experimental setup of this hysteresis regulator is used to generate the scalable data on regularities and evolution scenarios which are typical and potential for the analyzed dynamics. The presented results demonstrate novel experimentally verified facts about HDS-dynamics taking into account the context of the discussion on the physical basis of local climate dynamics that seems to be interesting for scientists in this field.

Specialized data processing aimed to the emergency forecasting on local climate dynamics over last century from the bifurcation analysis viewpoint can suppose analytics on specific phenomena which were out of considerations until recently. The paper discusses a pilot version of the computer software, where one of such phenomena (namely, so-called interannual temperature variability) is involved into the consideration in daily terms for time and temperature coordinates. Cycling is organized per a local climate system, where five logically independent procedures operate with specialized 3D-structure. Each 3D-structure consists of 20-50 thousands samples of the meteorological observations on land surface air temperature daily means. The theoretical base is provided by the conceptual model on local climate dynamics (so-called HDS-model), where both the amplitude quantization (limited by the temperature Hysteresis) and the time quantization (the Double Synchronization) compete. Thus alternations between three elementary dynamical processes with the same period (one year) and different patterns of annual warming-cooling cycles exist instead of traditional trend estimations calculated for the annual and/or monthly means. We believe that the results could be interesting for scientists and specialists in the research and practical fields connected with consequences of the climate changes.

The tendon-sheath mechanism (TSM) is applied to most flexible surgery robot systems because of its inherent advantages, such as small size, low weight, flexibility, and efficient power transmission. However, several uncertainties, friction, and backlash can cause hysteresis, which interferes with control of a surgical instrument. In this paper, the image-based hysteresis compensator is proposed. This compensator adjusts the position reference input using the visual-feedback concept. The proposed compensator utilizes learning-based pose estimation using a siamese convolutional neural network (Siamese CNN). It estimates the instrument position without using markers. The proposed method is evaluated in a testbed that is designed by considering the several requirements for an actual surgical instrument. As a result, we confirm that the image-based hysteresis compensator is able to decrease hysteresis. Moreover, the learning-based poses estimation works well without the use of markers. This result shows the feasibility of applying the proposed method to a real surgical robot system to facilitate hysteresis reduction.

© 2017 IEEE. We study the problem of secondary frequency regulation where ancillary services are provided via load-side participation. In particular, we consider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to Zeno-like behavior, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteresis on-off policy and provide stability guarantees in this setting. We provide numerical investigations of the results on a realistic power network.

Wireless Sensor Networks (WSNs) play very important role in development of smart cities and communication infrastructure. However due to its open nature WSNs are vulnerable to several kinds of attacks. One of the most important concern is a node inside the network getting compromised and behaving against the network policy. This leads to taking up wrong decisions by the nodes and the purpose of the sensor network is not served. Trust computation models are very effective to mitigate the internal attacks. In this paper we propose a differential method for evaluation of direct trust which uses the hysteresis curve for effective trust evaluation. We use the property of hysteresis curve to assess the trust value of a neighboring node based on its forwarding behavior. We compare the proposed method with the cos function.

Car accidents caused by driver's fatigue, inattention, drowsiness and illness are one of the leading reasons for preventable fatalities and injuries on the road. This paper studies the assistant driving problem for the nonlinear lateral dynamic model of vehicles in the lane keeping case. By means of the developed controller the car is able to keep itself in a given lane even if the human driver does not drive properly. The shared-control algorithm is based on a hysteresis switch and the formal properties of the closed-loop system are established via a Lyapunov-like analysis. Simulation results are presented to show the effectiveness of the driving assistant system.

This paper discusses a nonlinear Kelvin-Voigt-based (hysteresis) disturbance force model used in the estimation and compensation of both the hysteresis and dynamic forces caused by a cable-slab-stage system. The hysteresis model features rate-, position- and direction-dependent properties while also taking into account the time-varying/moving mass effect that is introduced by the motion of the cable slab. In terms of control, a model-based inferential feedforward approach is pursued that aims at attenuation of the hysteresis phenomenon such as experienced at the point-of-interest. The potential benefits of the proposed approach will be demonstrated by means of measurement results obtained from a sensor stage of an industrial in-line metrology system.

We study a class of optimal control problems for measure-driven differential equations with rate independent hysteresis. The hysteresis is modeled by an evolution variational inequality equivalent to the action of play operator generalized to the case of discontinuous inputs of bounded variation. A method to obtain optimality conditions for impulsive processes is proposed.

In this paper, impulsive control systems described by measure-driven differential equations with rate independent hysteresis are considered. Approximation results for impulsive processes are presented.

A hysteresis regulator with double synchronization (hereafter, HDS-regulator) realizes one of the promising ways to satisfy efficiency, simplicity and stability of pulse energy conversion. Here we focus on research of peculiar bifurcation-like effects in dynamics of HDS-regulators. Usually, bifurcations and states about bifurcation points mean either beginning or development of abnormal tendencies in pulse system dynamics towards technological risk. However, the bifurcation-like effects systematized and discussed in the paper seem to be rather useful than dangerous ones. We attract the technology of computer-based bifurcation analysis specialized for dynamical systems with variable structures in order to make clear this issue. A practical conclusion on the revealed peculiarities of HDS-regulators dynamics is formulated. We believe that the results could be interesting for researches and engineers in the field of pulse system control.

One of the most popular and easy to implement control strategy for the inverter in induction motor drive system is the hysteresis current control. The most drawbacks associated with the conventional hysteresis current controller is the variable switching frequency due to the constant hysteresis band. This paper aims to develop variable hysteresis band with fuzzy logic controller which can produce constant switching frequency. Matlab/Simulink environment was utilized to conduct the simulation of induction motor drives with three different configuration of hysteresis control; fixed hysteresis band, variable hysteresis band and fuzzy hysteresis band. The obtained results shows that, fuzzy hysteresis band produce better results than the fixed and variable band in which constant switching frequency, less ripple and reduced harmonics contents in the current waveforms. Hence fuzzy based hysteresis current controller proved to be superior in terms of switching frequency and harmonics contents.

This research attempts to extract and quantify dynamic emotion transition (DET) psychophysiological features. The DET features are defined and explored based on neurophysiological dynamics underlying emotion hysteresis theory, which could potentially explain individual differences in emotion processing of environmental changing stimuli. Directional changing stimuli probes are used for attentive and preattentive stimuli-induced emotional processing. Three progressive paradigms examine hysteresis with multimodal emotion detection techniques including central and peripheral physiological measurements. The DET, an individualized feature, representing abrupt changes in emotion responses, could lead to an enhanced Brain-Computer Interface system for monitoring stress and detecting changes in emotion. This could then provide timely restorative feedback stimuli for emotion regulation training. Moreover, this approach is promising for mental disorder diagnostic and prognostic tools.

An adaptive tracking control is proposed for a class of constrained nonlinear systems with hysteresis and uncertainty. Hysteresis and uncertainty may limit system performance such as giving rise to undesirable accuracy or oscillations, even leading to instability. First, Bouc-Wen model is used to describe the hysteresis, and the upper bound is derived. Then, a Barrier Lyapunov Function (BLF) is adopted to ensure the boundness and achieve the output-constrained conditions. Finally, the adaptive technique is used to approximate the uncertainty of the system and the backstepping controller is proposed to eliminate oscillation and overshoot caused by hysteresis. Furthermore, this controller eliminates the influence of the hysteresis, constraint and uncertain constants simultaneously. The simulation results are presented to illustrate the effectiveness of the proposed method.

Great deficiency of meteorological data seems to be one of its main features from the viewpoint of climate dynamics estimations. The deficiency is caused by non-renewable losses in past together with slow gathering in present. So, here we discuss one of the way how to use the available observations of land surface air temperature in order to get estimations on evolution of local climate dynamics. Since such dynamics is characterized by too high variety of nonlinear behaviors, then the bifurcation analysis remains the main tool to provide reasonable and impartial results concerning evolutional processes. In this context, we develop the approach to model-based reconstruction of the dynamics on the basis of so-called HDS-model (the model of a Hysteresis regulator with Double Synchronization). At present, only this conceptual model allows to describe the cause-and-effect relations between hysteresis phenomena and feed backs in a local space scale from the bifurcation analysis viewpoint. The idea of the research consists in the attempt to use the HDS-model in order to reconstruct nonlinear dynamics tendencies concerning the most actual fundamental points at least. In particular, we demonstrate the novel abilities concerning how to reveal constituents of latent evolutional processes which can not be recognized by other ways. We believe that the presented discussion could help to pay attention on local peculiarities of inevitable climate changes, and, after, could help to assess impartially climate and economic effects caused by such changes, especially, in relation to a point of no return.

Control schemes employing inverse-based hysteresis compensation are successful in accurate position control of smart material actuators. However, the effectiveness of the inverse hysteresis model in cancelling hysteresis is not addressed in the evaluation of these control schemes. Classical methods rely on closed-loop tracking error analysis which does not allow evaluation of the inverse model independent of the controller. This leads to lack of a deterministic measure of the amount of hysteresis cancelled by the model, while the influence of an inaccurate model on the overall tracking error also remains unclear. This paper proposes a framework to verify the effectiveness and accuracy of inverse hysteresis models by quantifying the hysteresis non-linearities remaining after hysteresis compensation. Further, by estimating the linear and residual non linear dynamics, valuable information is provided for controller design. The framework is experimentally validated for a Shape Memory Alloy (SMA) actuator. The framework can be seen as a tool to explore and compare different inverse hysteresis models prior to controller design.

In recent years, Hardware-In-the-Loop (HIL) simulation such as RT-LAB, RTDS are widely used in power electronic system study. In order to keep the simulation accuracy, the main concern of researchers normally focuses on the minimum simulation step size of the simulator, while neglects the role of input-to-output delay of the simulator. Concentrating on the study of hysteresis current control of grid connected converter, this paper investigates the importance of the simulator delay. With theoretical analysis, simulation and experiments, it is found out that the delay of the simulator seriously affects the control performance: it can apparently increase the hysteresis current band, reduce the switching frequency, increase the current THD (Total Harmonic Distortion) and therefore deteriorate the control. With the input-out-delay, even if the simulation step is kept small, the simulation results are neither accurate nor trustable. Upgrading the simulator hardware to reduce the delay might be feasible in future but definitely very costly. While upgrading hardware is not a final solution, as an alternative software solution, this paper proposes a novel time expansion method. The experimental results prove that the proposed time expansion method can effectively cope with simulator delay in the HIL study of hysteresis current control, making it possible to achieve satisfactory performance with an ordinary simulator.

Hysteresis is basically a circuit nonideality but in some applications it is used to prevent the comparator's outputs from toggling back and forth between logic levels when solving small inputs in noisy environments. This paper presents an enhanced latch comparator where hysteresis can be handled and adjusted to specific values. A frequency domain analysis of the latch comparator operating at the beginning of the comparison process is performed and has shown to be efficient in predicting hysteresis and circuit behavior at high clock frequencies. In the light of the predicted features, a new latch comparator has been proposed to enhance hysteresis and speed and was designed using a commercially available 0.18μm CMOS technology. It operates under a power supply of 1.8 V, with a clock frequency of 800MHz and consumes an average power of about 90μW. Compared to the common basic structure when considering a 1.4mV hysteresis, simulation results of the proposed comparator have shown that hysteresis can be easily adjusted to about 300μν without trading design complexity or time delays.

This work presents a novel Model Predictive Hysteresis Current Control scheme for Synchronous Reluctance machine.

In this paper, a non-smooth control scheme is proposed for control of mechanical transmission systems with gearbox demonstrating nonsmooth hysteresis. In order to handle the control of mechanical systems with hysteresis, a nonsmooth predictive control strategy is proposed. It is noted that the method of conventional optimization is not suitable for the minimization of objective function due to the nonsmooth property of hysteresis. In this paper, a non-smooth nonlinear programming based nonsmooth receding horizon strategy is proposed to tackle the problem of on-line predictive control.

This paper considers the fusion of hysteresis constraint with the image-based visual servoing(IBVS) manipulator system. Compared with the conventional IBVS system, we fully consider the unknown hysteresis nonlinearity which widely exists in the real mechanical systems. To eliminate the effect arisen by the actuator hysteresis constraint, we propose a novel adaptive algorithm to estimate the unknown hysteresis parameters on-line. Without knowing the uncertain parameters intervals and the bound of the disturbance term, an adaptive robust controller is developed. Simulations are carried out to test the performance of the proposed controller.

In this paper, convergence rate and accuracy are studied for self-optimization systems. It was also shown that the estimate of the accuracy is higher than previously published studies. The convergence rate is compared with a modified algorithm which implies a decreasing rate of reference input.

Hysteresis is the main thermal effect that must be compensated after bias and scale factor calibration for inertial grade accelerometers. If the hysteresis comes only from dynamic lag between the temperature and bias, this effect should disappear for an adiabatic change of the temperature. In this case the effect is referred to as rate dependent hysteresis. However, some sensors present a residual hysteresis even for a temperature quasi adiabatic change; we call this effect quasi rate dependent hysteresis. In this paper, we present an algorithm to compensate sensors for a quasi-rate dependent hysteresis. We describe the main ideas behind the hysteresis calibration process, and present a calibration example for a Tamam accelerometer.

We examine a data-dependent dwell-time switching algorithm in which the dwell-time is constrained to grow in proportion to the reciprocal of an adaptively-computed hysteresis variable ĥ(t) that converges to zero. This is in contrast to the Morse-Mayne-Goodwin (MMG) hysteresis switching algorithm in which usually a fixed hysteresis constant h > 0 is used. The algorithm is proved to be globally stabilizing assuming feasibility and τ c -cost-detectability. It has the attractive property that the gap between optimal and achieved unfalsified performance levels are at each time bounded above by the current value of the hysteresis variable ĥ(t), thereby ensuring asymptotically optimal performance. A simulation example demonstrating this performance improvement is presented.

The advantage of hysteresis regulators with double synchronization (HDS-regulator) is connected with the promising combination of the operational and ecological characteristics of the energy conversion process. It causes the increase in interest to study in more detail the HDS-regulator dynamics in application to technical and nature nonlinear systems. And the following question seems to be the most important: whether latent abnormalities in operating process dynamics are possible? The question is actual due to the dominant behavior represents the ensemble of several periodical processes with the same periodicity and different orders of structural changes. The paper focuses on the abnormalities stimulated by the regular interplay between noise and nonlinear effects at the moments of the structural changes. In particular, the mathematical model to describe the interplay is proposed based on the analysis of the experimental bifurcation diagrams. The model represents the variant how to describe the result of the specific effects observed during experimental researches. It is shown that the latent abnormalities can appear due to the amplification of the initially temporary subtle disturbances to the quite long discernible behavior which likes the forthcoming stage of an abnormal process. The scenarios of the HDS-regulator dynamics evolution with/without the proposed model are compared to estimate where the domains of the reveled latent abnormalities can be allocated in the parametrical space. Finally, the comments concerning the influence of the abnormalities on the HDS-regulator operating dynamics are presented.

The hysteresis of the outbound handover in heterogeneous networks (HetNets) with both a macrocell and small cells is investigated in this paper. The hysteresis has a significant effect on the handover performance in terms of the handover initiation delay and unnecessary handovers. Meanwhile, the User Equipment (UE) speed is a critical factor which has a dramatic influence on the handover performance in the mobility management. To determine the hysteresis value effectively, we propose a hysteresis automatic configuration (HAC) algorithm based on the UE speed aims to obtain an optimized hysteresis for the UE during the outbound handover process. System-level simulations are presented and the results reveal that our proposed algorithm outperforms existing approaches in terms of reducing the radio link failure rate and the call-drop rate and achieves a better utility of the outbound handover.

To achieve excellent multiple arms manipulation, it should not be possible to ignore the hysteresis nonlinearity in the actuator due to its wide existences in the mechanical systems and electrical devices. In this paper, an adaptive fuzzy control, which takes the input hysteresis into account, is constructed for the multiple arms system. Departing from the existing adaptive fuzzy approaches, the proposed method uses only one learning parameter to approximate the robotic dynamics. Therefore, it significantly reduces the computational burden in controlling the multiple arms manipulation.

DC renewable energy sources and dc loads are gaining attraction and they are preferably connected in dc microgrids. To increase the availability of dc microgrids, voltage dependent demand response should be used to switch off low priority loads in case of insufficient supply. This is possible even without communication with the loads. In this paper it is shown that using a voltage hysteresis with fixed thresholds to switch loads on and off, does not provide a general solution and oscillations can occur in specific cases. Dynamic hysteresis thresholds are introduced as a mean for devices to autonomously learn the present behavior of the grid to which they are connected.

This paper is concerned with the problem of stabilization for positive switched delay systems. A hysteresis switching law is designed to stabilize positive switched systems with a time delay. On one hand, such switching laws can eliminate the chattering resulting from state-dependent switching laws. On the other hand, a constant time delay may sometimes lead to the instability of positive switched systems. Sufficient conditions on the existence of hysteresis switching laws are presented by making use of linear programming approach. The validity of the proposed approaches is illustrated by a numerical example.

In this paper, robust control for nonlinear uncertain systems with backlash-like hysteresis is considered by using operator based robust right coprime factorization approach. In details, a continuous backlash-like hysteresis operator is discussed and the existence of one-to-one hysteresis operator is proved under a sufficient condition. Moreover, an operator based control design structure is proposed for nonlinear uncertain system with backlash-like hysteresis. Based on the proposed design scheme, the designed system is robustly stable and the desired output tracking performance can be realized simultaneously. Finally, a simulation example on a nonlinear plant preceded by backlash is given to show the design procedure of the proposed method.

The optimal choice of switches within a hysteresis controller with a d-q-related constraint is discussed in this paper. The hysteresis controller controls a bidirectional two-level three-phase standard inverter. This paper expands the options of switching processes to a former published d-q-hysteresis controller. Despite a separate active and reactive hysteresis constraint which is offered, further advantages for the d-q-controller are evaluated. This Paper describes the main functionality of the floating d-q-hysteresis controller and demonstrates a comparison with the α-β-control-structure.

The paper develops a state-space model for the aggregate power drawn by a group of plug-in electric vehicle (PEV) chargers under hysteresis-based charging. The aggregate response of the PEV charging loads to changes in the hysteresis deadband is nonlinear, requiring detailed analysis to accurately capture the dynamics. Related work, which focused on thermostatically controlled loads (TCLs), addressed state-space modelling by dividing the hysteresis deadband into equally sized bins and keeping track of the inter-bin migration of loads. A system of PEV chargers can be treated similarly. A new modelling paradigm has been developed to allow for fast variation of the hysteresis deadband. This model tracks the distribution of PEV chargers within the hysteresis deadband, with the inter-bin migration of chargers used to capture the aggregate dynamics.

The paper develops a hysteresis-based charging control strategy for plug-in electric vehicles (PEVs) that is capable of regulating charging load to satisfy system-wide services, including filling the overnight demand “valley” and balancing fluctuations in renewable generation. The actual state-of-charge (SoC) of a PEV battery follows a nominal SoC profile within a small hysteresis band. This leads to a sequence of ON and OFF cycles for the charger. The paper shows that in steady-state the probability distributions of SoC in the ON and OFF states, normalized around the nominal profile, follow a uniform distribution over the hysteresis deadband. Based on this steady-state behavior, a linearized state-space model has been developed to capture the response of aggregate electricity demand to shifts in the nominal SoC profile. A feedback control law is designed based on this linearized model.

A practical concern with implementing the fixed band hysteresis current control in active power filters (APF) is its variable switching pattern that results in increasing the risk of occurrence of resonance in power systems. To avoid this situation, adaptive hysteresis current control methods with the variable hysteresis bands have been recommended in literature. However, these methods impose an absolutely huge amount of complex computations on the system which, in turn, slows down its response time and thereby, limits the switching frequency. This paper devises a novel fixed-band fixed-frequency (FBFF) hysteresis current control strategy that aims to eliminate completely the mentioned calculations while keeps merits of the adaptive methods. In other words, the suggested strategy employs an algorithm that is similar to the fixed-band variable-frequency hysteresis methods; however, the outcomes are identical to the variable-band fixed-frequency hysteresis current control techniques. Employing the proposed FBFF method to control an APF leads to an accurate modulation performance with the least possible calculations required in a filtering procedure. Several simulations are done using MATLAB/Simulink to verify validity of the proposed method.

Focusing on a class of pure-feedback nonlinear time-delay systems with unknown hysteresis input, an adaptive control method is discussed in this paper. For such nonlinear systems, the nonaffine structure and the non-smooth hysteresis nonlinearities are the major challenges for the controller design. To deal with the nonaffine problem of pure-feedback systems, mean-value theorem is adopted to transform the systems as affine form, and neural network approximator is utilized to estimate the unknown system functions. For the unknown preceded hysteresis nonlinearities, the Backlash-like model is utilized as an illustration to show the way dealing with the unknown hysteresis input. Following the backstepping design procedure, a dynamic surface control approach is investigated to avoid the complexity of controller by applying the low-pass filters at each step, and the semiglobal uniform ultimate boundedness of the signals in the closed-loop system is ensured. The proposed control method explores the validity mitigating the negative effects caused by the unknown hysteresis, and the simulation results validate the effectiveness of the proposed design scheme.

Previous studies have shown hysteresis in transition from 1∶1 to 2∶2 rhythms in action potential durations (APD) during decreasing and increasing cycle length pacing. As cycle lengths were constant, when alternans of APD occurred, so did of preceding diastolic intervals (DIs), which engaged the restitution mechanism, i.e. dependence of APD on preceding DI, making it impossible to determine whether the hysteresis originates from the DI independent or dependent mechanism. By using pacing with explicit control of DI, in the present study we investigated whether hysteresis in activation threshold exists in DI independent mechanism of alternans of APD. Transmembrane potentials were recorded from the left ventricles of 6 farm pigs, and the state transition was obtained from two pacing protocols where DIs decreased and increased in steps of 10 msec between 50 and 20 msec with 30 (15) beats at each DI level. Results showed hysteresis: for the 30 (15) beats protocol, onset and termination of alternans occurred at 27 (33) and 47 (49) msec DIs; average alternans amplitude was 22 (13) and 26 (15) msec for decreasing and increasing DIs. Because constant DI pacing was used, restitution dependent effect was eliminated, therefore, observation of hysteresis in our results suggests that restitution independent mechanisms such as activation memory also contribute to the hysteresis in this state transition.

The self-oscillatory system with hysteresis has been widely studied. However, most research deal with one hysteresis element in the system, seldom discuss the multi-hysteresis controllers, not to mention interactions between them. In the paper, we take a simple model with two coupled hysteresis controlled integrators as an example to study a synchronous phenomenon, that is similar to that happened in the large-scale distributed hysteresis controlled system, e.g. the supermarket refrigeration system. In the paper, synchronization is interpreted as a limit cycle in a state space created by switching among piecewise-affine dynamical system. Stability of the resultant limit cycle is examined by a Poincar'e map. We show that the synchronization takes place if the corresponding Poincar'e map is stable.

Hysteresis smoothing is a filtering method for one-dimensional data, which removes waveform noise with a simple but powerful process. Although it may be applied in two-dimensional data, an inherent problem of severe artifacts makes it difficult to use this method on SAR imagery. In this paper, we take notice of a property appeared when hysteresis smoothing works well on homogeneous areas. We propose a simple rule to exploit this advantage without losing the merits of the original approach. The effectiveness of our approach is demonstrated quantitatively and qualitatively with simulated and real Ku-band SAR data.

Recently, robots not only have been researched and developed actively but also have replaced humans in several fields such as medical treatment and nursing. For robots to coexist with humans and provide support, they must have human-like dexterity and should be very safe. Therefore, pneumatic actuators are used to develop safe and lightweight robot hands. However, the relationship between the internal pressure and contraction ratio of pneumatic actuators is nonlinear, with a hysteresis characteristic and a dead zone. Moreover, the nonlinear characteristics of pneumatic actuators change with the applied load. In this study, we proposed a hysteresis model that can express the change in these hysteresis characteristics, and we constructed a control system that integrated this hysteresis compensation by using the proposed hysteresis model.