On-off Control Research Articles

An Inverter Circuit Configuration Suitable for Vessels of Different Material for Multiload Induction Cooking Application

In heating applications, induction heating (IH) is a dominant technology in the market due to several advantages over conventional heating techniques. Most of the research in the past has focused on heating ferromagnetic material type vessels. Now, there is an increase in research for proposing topologies suitable for heating ferromagnetic (FM) and Non-ferromagnetic (N-FM) type vessels. In this paper, an inverter circuit is proposed for heating FM and N-FM material vessels. A simple ON-OFF control is used for obtaining simultaneous as well as independent control for both the loads. It offers linear power control. The range of power control for N-FM load is increased by using frequency based control. The proposed inverter circuit has been simulated in OrCAD PSpice and experimentally verified with a prototype for 1624 W. It offers a peak experimental efficiency of 94.3%. It can also be extended for multiple loads by adding a low frequency operated switch and a diode combination for additional IH load. A detailed loss analysis for the proposed inverter has been carried out using PSIM software. The simulation and experimentation results are in good accord with each other. Hence, the proposed inverter circuit is a suitable solution for heating FM and N-FM material vessels for multi-load applications.

On-Off and Proportional Closed-Loop Adaptive Deep Brain Stimulation Reduces Motor Symptoms in Freely Moving Hemiparkinsonian Rats

ObjectivesClosed-loop adaptive deep brain stimulation (aDBS) continuously adjusts stimulation parameters, with the potential to improve efficacy and reduce side effects of deep brain stimulation (DBS) for Parkinson’s disease (PD). Rodent models can provide an effective platform for testing aDBS algorithms and establishing efficacy before clinical investigation. In this study, we compare two aDBS algorithms, on-off and proportional modulation of DBS amplitude, with conventional DBS in hemiparkinsonian rats. Materials and MethodsDBS of the subthalamic nucleus (STN) was delivered wirelessly in freely moving male and female hemiparkinsonian (N = 7) and sham (N = 3) Wistar rats. On-off and proportional aDBS, based on STN local field potential beta power, were compared with conventional DBS and three control stimulation algorithms. Behavior was assessed during cylinder tests (CT) and stepping tests (ST). Successful model creation was confirmed via apomorphine-induced rotation test and Tyrosine Hydroxylase–immunocytochemistry. Electrode location was histologically confirmed. Data were analyzed using linear mixed models. ResultsContralateral paw use in parkinsonian rats was reduced to 20% and 25% in CT and ST, respectively. Conventional, on-off, and proportional aDBS significantly improved motor function, restoring contralateral paw use to approximately 45% in both tests. No improvement in motor behavior was observed with either randomly applied on-off or low-amplitude continuous stimulation. Relative STN beta power was suppressed during DBS. Relative power in the alpha and gamma bands decreased and increased, respectively. Therapeutically effective adaptive DBS used approximately 40% less energy than did conventional DBS. ConclusionsAdaptive DBS, using both on-off and proportional control schemes, is as effective as conventional DBS in reducing motor symptoms of PD in parkinsonian rats. Both aDBS algorithms yield substantial reductions in stimulation power. These findings support using hemiparkinsonian rats as a viable model for testing aDBS based on beta power and provide a path to investigate more complex closed-loop algorithms in freely behaving animals.

Optimal Power Quality Control Model of Magnetic Latching Relay for Charging Station Based on Adaline

In order to eliminate the internal harmonics of the magnetic latching relay caused by the load input, an ADALINE-based magnetic latching relay power quality optimal control model for charging stations was constructed. Calculate the sampling point of the input signal through the ADALINE neural network, obtain the error signal between the input signal and the measured signal, use the VSLMS algorithm to continuously adjust the weight value to update the spectrum in real time, detect the harmonics existing in the magnetic latching relay, and use the harmonics. The droop control strategy calculates the amount of harmonic voltage that needs to be compensated, and participates in the on-off control of the magnetic latching relay by calculating the modulation wave difference formed by the fundamental wave and the harmonic voltage closed loop, eliminating the harmonics generated by the nonlinear load, and realizing electric energy optimal quality control. The experimental results show that the model can accurately detect and eliminate the internal harmonics of the magnetic latching relay caused by the load input, and has a better control effect on the power quality of the magnetic latching relay used in the charging station.

A GM-Based Energy Management Strategy of Hybrid Power System for Hydrogen Fuel Cell Buses

Hydrogen energy is a clean, carbon-free, flexible, efficient, and widely used secondary energy source, which is an ideal alternative to promote the clean and efficient use of traditional fossil fuels. Hydrogen fuel cell bus has the advantages of a high-energy conversion rate, absolute pollution-free, sufficient raw materials, and convenient filling. The hybrid power system, composed of fuel cell and auxiliary energy source, is one of the key technologies to promote the development of hydrogen fuel cell vehicle. This study aims to propose an energy management strategy by analyzing the output characteristics and power allocation of fuel cell and power battery in the hybrid power mode with fuel cell as the main and battery as the auxiliary. A GM (1, N) power prediction strategy was proposed and compared with other strategies as an on-off control strategy and logical threshold value strategy in this study. The variation curves of the battery SOC and fuel cell output power under two working conditions of CCBC and real vehicle conditions were analyzed by using these three strategies, when the initial SOC of power battery is 30%, 70%, and 90%, respectively. Results showed that the power prediction strategy based on GM (1, N) has a better performance in output efficiency and fuel economy when compared to the other two strategies by analyzing the aspects of the battery in the SOC variation and equivalent hydrogen consumption and the fuel cell in the output power variation and hydrogen consumption. This research can be helpful to provide the suggested solution for energy management of the hybrid power system for hydrogen fuel cell buses.

A scaled-down model of a dairy barn to imitate a livestock building for modelling and control of environmental conditions

Heat stress has vital importance in livestock farming due to the physiological changes on the animals so that meat and milk production is significantly degraded. Recently, the hereditary and mental effects of environmental conditions have also been discussed for future generations. Therefore, high-level automation solutions are required to keep the environmental conditions in the barns as optimal as possible. In this paper, a hangar-type scaled-down barn was experimentally designed for modelling and control of the environmental conditions. First, the temperature-humidity index (THI) which is a measure of the heat stress, was stabilized to its critical value in two regions of the barn by using proportional-integrative-derivative (PID) controller. The ventilation fans were controlled at variable speeds so that energy efficiency was also provided when compared to the on-off control. Second, we proposed the state-space modelling of the coupled temperature and humidity dynamics for the interior space of the barn so that the obtained model can be utilized for mathematical analysis and accurate control. Specifically, state monitoring and prediction, optimal control, and observer-based sensor-less control are to be applied based on its state-space model. The parameters of the state-space model were here estimated with an Extended-Kalman Filter (EKF). Performances are calculated in terms of mean square error (MSE), and the performance values were found to be less than 5% for stabilization and less than 2% for modelling, respectively. The proposed scaled-down barn model is a low-cost design that can be used as an example for those who work in this field to conduct experimental studies before making large investments. Barn design can also be modified for modelling, analysis, and control of new heat stress measures in the future.

METAL-BASED THREE-DEGREE-OF-FREEDOM ACTUATOR WITH SHAPE MEMORY

A three-degree-of-freedom actuator was implemented using shape memory metals (SMA) for two-dimensional movement. In its design, a CAD software was used, analyzing the movements made by a ball joint, obtaining a conical body with a circular base. For its movement, a one-way SMA spring arrangement was implemented as opposed to a two-way one for displacement in each of the XY axes, and its rotation by means of a bearing coupled to the axis of the body that allows rotation in one direction. actuator. An on-off control was implemented based on a kinematic study that can be manipulated through an interface that, according to the temperature and position obtained, activates or deactivates the SMA elements. As a result, the working angle was determined in a two-dimensional plane of ±22.5° and 30º counterclockwise for its rotation, taking into account that its error grows as it moves away from its center.

Fast on-off jet control of aerosol jet printing (AJP) using internal rotary valve

Aerosol jet printing (AJP) has been used in additive manufacturing sectors because it has advantages over conventional printing due to its capability of micro-pattern printing on various surfaces including a non-flat (3D) substrate with higher aspect ratio. Since the aerosol systems rely on continuous jet stream, one of the key issues is how to control the on-off of the jets to obtain desired patterns. An external shuttering system outside the nozzle was used to block the jet on non-printing regions. However, there are some downsides, for example, non-optimal stand-off distance due to mechanical interference, unwanted accumulation of the ink on the shutter, and possible mechanical interference when printing on curved surface or surfaces with protrusions. The purpose of this study is to develop AJP system with an internal rotary valve to eliminate the problems of the external shutter. The proposed internal two-way rotary valve can select the jet direction for printing or diverting the jet stream to the air. However, there was jetting delay because it takes time to stabilize the internal pressure. This delay results in non-uniform printing especially when resuming printing from off. In this study, we investigate the pressure behaviors of the flow cell under internal shutter on-off conditions and proposed a new flow rate control method capable of fast on-off control for uniform printing.

Pinning control of social fairness in the ultimatum game

Decent social fairness is highly desired both for socio-economic activities and individuals, as it is one of the cornerstones of our social welfare and sustainability. How to effectively promote the level of fairness thus becomes a significant issue to be addressed. Here, by adopting a pinning control procedure, we find that when a very small fraction of individuals are pinned to be fair players in the ultimatum game, the whole population unexpectedly evolves into the full fairness level. The basic observations are quite robust in homogeneous networks, but the converging time as a function of the pinning number shows different laws for different underlying topologies. For heterogeneous networks, this leverage effect is even more pronounced that one hub node is sufficient for the aim, and a periodic on-off control procedure can be applied to further save the control cost. Intermittent failures are seen when the pinning control is marginally strong, our statistical analysis indicates some sort of criticality. Our work suggests that the pinning control procedure could potentially be a good strategy to promote the social fairness for some real scenarios when necessary.

A Physics-Based Modelling and Control of Greenhouse System Air Temperature Aided by IoT Technology

The need to reduce energy consumption in greenhouse production has grown. Thermal heating demand alone accounts for 80% of conventional greenhouse energy consumption; this significantly reduces production profit. Since microclimate affects crop metabolic processes and output, it is essential to monitor and control it to achieve both quantity and quality production with minimum energy consumption for maximum profit. The Internet of Things (IoT) is an evolving technology for monitoring and controlling environments that have recently been adopted to boost greenhouse efficiency in many applications by integrating hardware and software solutions; therefore, its adoption is thus critical in enabling greenhouse energy consumption minimisation. The first objective of this study is to improve and validate a greenhouse dynamic air temperature model required to simulate or predict indoor temperature. To achieve the first objective, therefore, an existing model was enhanced and a closed loop test experimental data from the IoT cloud-based control system platform deployed in the prototype greenhouse built in Cranfield University was used to validate the model using an optimisation-based model fitting approach. The second goal is to control the greenhouse air temperature in simulation using relatively simple PI and on-off control strategies to maintain the grower’s desired setpoint irrespective of the inevitable disturbances and to verify the potential of the controllers in minimising the total energy input to the greenhouse. For the second objective, the simulation results showed that the two controllers maintained the desired setpoint; however, the on-off strategy retained a sustainable oscillation, and the tuned PI effectively maintained the desired temperature, although the average energy used by the controllers is the same.

A Study on the Control System of Electric Water Heaters for Decarbonization

Greenhouse gas (GHG) emissions have significantly increased in recent years as a result of population rise and the increase in the number of residences, with high levels of energy use in homes and household appliances. It is crucial to move the housing industry away from high-carbon sources and toward low-carbon sources in order to minimize greenhouse gas emissions as a precaution. One of the most crucial systems that needs to be provided in order to achieve energy efficiency is the electric water heater (EWH), as they rank among the top electricity consumers. In this study, a double-tank EWH model was developed and simulated at various tank sizes (100 L, 200 L, 300 L and 400 L) and power ratios (1 kW, 2 kW, 3kW and 4 kW) in order to demonstrate energy efficiency. To obtain information for the simulation analysis of the tanks, the hourly water usage of 25 houses was measured. The single-tank and the double-tank models created for this study were both run in the Matlab/Simulink environment with an on-off controller applied, and their energy consumption was compared. Amounts were also determined based on how much energy both tanks consumed. It has been noted that the amount of GHG emissions is also reduced because the double tank uses less energy than the single tank does. The simulation showed that compared to the single tank, the dual tank produced 46.62% less GHG emissions at 45 W power and 47.51% less GHG emissions at 80 W.

Dual-Band CMOS Low-Noise Amplifier Employing Transformer-Based Band-Switchable Load for 5G NR FR2 Applications

This letter presents a dual-band complementary metal–oxide–semiconductor (CMOS) low-noise amplifier (LNA) for fifth-generation (5G) new radio (NR) frequency range 2 (FR2) applications. The proposed design utilizes a transformer-based band-switchable load to tune resonance conditions in the 26–30- and 37–40-GHz bands. Through ON–OFF control of the transformer functionality, the primary inductance can be adjusted with lesser quality-factor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -factor) degradation compared to the conventional direct inductor switching approach. The proposed design is implemented using a 65-nm CMOS process. At 28 and 39 GHz, respectively, the gains of 13.7 and 13.1 dB, noise figures (NFs) of 3.8 and 4.1 dB, input 1-dB compression points of −15.2 and −16 dBm, and input third-order intercept points of −7.15 and −6.85 dBm are realized. The implemented design draws a bias current of 11.6 mA with a 1-V supply.

Development of Programming Teaching Materials that show the Effect of Feedback Control

Feedback control, which is said to originate from a speed governor that controls the rotation of a steam engine, is widely used. However, the effect of the feedback control may be difficult to understand for beginner. This paper reports the results of developing teaching materials that show how feedback control improves control performance compared to simple ON-OFF control.

Co-Optimization of Design and Control of Energy Efficient Hybrid Electric Vehicles Using Coordination Schemes

AbstractDesign and control co-optimization studies for hybrid vehicles have been proposed in the past. However, such works suffer from difficulties arising due to (a) diverse real- and integer-valued variables, (b) complex nonlinear powertrain dynamics and design interconnections, (c) conflicting objective functions with path constraints, and (d) high computational resources requirements. To meet these challenges, this study presents an efficient co-optimization framework for hybrid electric vehicles (HEVs) which is built using existing algorithms and coordination schemes. Particular emphasis is given to the simultaneous scheme and the decomposition-based scheme. The decomposition-based scheme with the problem decomposition proposed in this work can efficiently handle multitime scale state variables and both integer- and real-valued design and control optimization variables. This is demonstrated by solving the mixed-integer optimal design and control problem of a series hybrid vehicle over a 1-h long drive cycle with time discretization of 1 s. The problem complexity is elevated by using an increasing number of state variables (including battery state of charge, battery energy, and after-treatment system temperature), control variables (such as the engine power and engine on/off), and design parameters (such as the number of battery cells and the type and size of the engine). In addition, a multi-objective cost function is used to find a tradeoff solution between fuel consumption and emissions minimization. The results show that in terms of optimality of the solution, the decomposition-based scheme is comparable with the simultaneous but can give a 14% improvement in computational performance. The effectiveness of the proposed framework is demonstrated by comparing the co-optimization results against a baseline case in which only the optimal control problem is solved. The co-optimized solution yields up to 3.7% average genset efficiency improvement and a fuel consumption reduction to 1.6 kg from 2.5 kg, which is further reduced to 1.5 kg by adding the engine on-off control. Finally, a decision matrix is developed to provide guidance on the selection of the optimization algorithm and coordination scheme for any problem at hand.

Revealing the nature of the graphene on-off control of the electrolyte gating effect in WO3 film phase transition

Electrolyte gating-induced metallization has been broadly observed in various transition metal oxides for decades, while the gating mechanism is still under debate. In this work, we realize the Insulator-Metal Transition (IMT) control of WO3 film by inserting a few-layer graphene. It's found that a sharp IMT process in WO3 film emerges if applying an electrolyte gating treatment, while this IMT behavior will be strikingly suppressed if inserting a graphene layer between the WO3 film and ionic liquid. Interestingly, the pronounced IMT behavior can be always observed if substituting the ionic liquid by acid solution, regardless of graphene layer insertion or not. According to the first-principles calculations, the diffusion energy barriers for the hydrogen or oxygen propagating graphene layer are extracted, and then the mechanism of electrolyte gating in WO3 films is proposed. Moreover, the roles of hydrogen and oxygen vacancy on the WO3 IMT process are further discussed based on the band structure calculations. Our current study will boost the development of electrolyte gating technique and bring deeper understanding of the electrolyte gating treatment for other transition metal oxides.

Integrated Design Fabrication and Control of a Bioinspired Multimaterial Soft Robotic Hand.

Machines that mimic humans have inspired scientists for centuries. Bioinspired soft robotic hands are a good example of such an endeavor, featuring intrinsic material compliance and continuous motion to deal with uncertainty and adapt to unstructured environments. Recent research led to impactful achievements in functional designs, modeling, fabrication, and control of soft robots. Nevertheless, the full realization of life-like movements is still challenging to achieve, often based on trial-and-error considerations from design to fabrication, consuming time and resources. In this study, a soft robotic hand is proposed, composed of soft actuator cores and an exoskeleton, featuring a multimaterial design aided by finite element analysis (FEA) to define the hand geometry and promote finger's bendability. The actuators are fabricated using molding, and the exoskeleton is 3D-printed in a single step. An ON-OFF controller keeps the set fingers' inner pressures related to specific bending angles, even in the presence of leaks. The FEA numerical results were validated by experimental tests, as well as the ability of the hand to grasp objects with different shapes, weights, and sizes. This integrated solution will make soft robotic hands more available to people, at a reduced cost, avoiding the time-consuming design-fabrication trial-and-error processes.

Rule-Based On-Off Traffic Control Strategy for CAVs on Motorway Networks: Assessing Cooperation Level and Driving Homogeneity

Connected and automated vehicles (CAVs) attract much attention due to their unique behavioral characteristics and the promise to transform road transport systems as we know them today. However, the behavior of such vehicles on the road is not homogeneous since each manufacturer offers different implementations. Cooperation is essential to homogenize the traffic flow of CAVs and prevent delays on congested networks with high demand. This work proposes a rule-based decentralized on-off cooperation strategy at merging locations on freeway networks using CAVs as mobile actuators. The proposed strategy handles bilateral conflicts at on-ramps between vehicles with conflicting trajectories, taking actions at the vehicle level in a lateral or longitudinal direction, to minimize the disturbance for the following vehicles. Furthermore, heterogeneity among such vehicles is assessed through different parameter distributions among CAVs to demonstrate the importance of ensuring homogeneous dynamics in the vehicle operation design. Microscopic simulation is used to demonstrate the robustness of the proposed strategy and the value of homogeneous dynamics. The results show that the average network delay time decreased by up to 46%. Homogeneous driving behavior amplifies the benefit of the cooperative strategy significantly.

Light controlled reversible Michael addition of cysteine: a new tool for dynamic site-specific labeling of proteins.

Cysteine-based Michael addition is a widely employed strategy for covalent conjugation of proteins, peptides, and drugs. The covalent reaction is irreversible in most cases, leading to a lack of control over the process. Utilizing spectroscopic analyses along with X-ray crystallographic studies, we demonstrate Michael addition of an engineered cysteine residue in human Cellular Retinol Binding Protein II (hCRBPII) with a coumarin analog that creates a non-fluorescent complex. UV-illumination reverses the conjugation, yielding a fluorescent species, presumably through a retro-Michael process. This series of events can be repeated between a bound and non-bound form of the cysteine reversibly, resulting in the ON-OFF control of fluorescence. The details of the mechanism of photoswitching was illuminated by recapitulation of the process in light irradiated single crystals, confirming the mechanism at atomic resolution.

Kontrol Nutrisi Tanaman Hidroponik Berbasis Monitoring Internet of Things

Hydroponics is a way of farming that does not use soil, but only uses water that contains nutrients. The growth of hydroponic plants can be influenced by various factors, one of which is a lack of water nutrition in hydroponic plants. Therefore, this study aims to create a system that functions to control water nutrition, as well as the availability of sufficient water in hydroponic reservoirs. This control process uses NodeMCU esp8266 and processes sensor data and then sends it to firebase which will be displayed to Android with Internet of Thing (IoT) technology. If the nutritional condition being monitored is reduced, this nutrition control device will receive input from the sensor to add nutrients automatically. The addition of nutrients uses an on-off control system, when the TDS sensor reads the water nutrients are reduced the nutrient pump will be on until it reaches the initial nutrient setpoint, then the nutrient pump will be off. The result of reading sensor data obtains the percentage error for the Total Dissolve Solid (TDS) sensor with a comparison of TDS meter of 5.746%.

A frequency-dependent variable damping control method for base-isolated structures under ground motions with different frequency characteristics

The base isolation technique is commonly adopted to protect important structures from earthquake damages. Typically, a high damping ratio for the base isolation layer is useful in reducing the structure's resonance effect under low-frequency (long-period) ground motions, and a low damping ratio is preferred in minimizing the acceleration response under high-frequency (short-period) ground motions while not causing significant displacement response. To realize optimal control for base-isolated structures under ground motions with different frequency characteristics, the semi-active control is adopted and a frequency-dependent variable damping (FVD) control method based on a transmissibility weighted fast Fourier transform (TWFFT) spectrum is newly proposed. The FVD control method considers the influences of different frequency components of ground motions on base-isolated structures by developing the TWFFT spectrum of the detected ground accelerations. A series of shaking table tests for a base-isolated steel frame structure with semi-active control were carried out to evaluate the effectiveness of the FVD control method. The test results demonstrated that the FVD control method could realize optimal control of the structure under various types of ground motions, and it was more effective than the ON-OFF control method which only considered the dominant frequency characteristics of the ground motions.

Embedded remote monitoring system based on NBIOT

With the rapid development of information technology, the remote control has become an important means to improve production efficiency and intelligence level. In this paper, an embedded remote control system based on NBIoT technology is designed and produced. Based on STM32F427 as the control core, the system can collect the current and voltage of each branch and perform data analysis, data processing, and branch on-off control. It connects multiple smoke sensors to realize the fire warning function. Data transmission is realized through NBIoT technology and the OneNet platform, and users can realize remote control through APP. Multiple built-in communication interfaces can be extended for different scenarios. It has a good effect on the test and can meet the requirements of remote control. It has high application value in industrial control, smart city, and other fields.