Double Integral Sliding Mode Controller Research Articles

Variable structure based control strategy for treatment of HCV infection

Hepatitis C is such a harmful disease which can lead to serious health problems and it is caused by the Hepatitis C Virus (HCV) which causes liver inflammation and sometimes liver cancer. In this work, the control treatment strategy for HCV infection has been proposed. The advanced nonlinear dynamical mathematical model of HCV that has two control inputs and three state variables such as virions, infected hepatocytes and uninfected hepatocytes are considered for controller design in this research work. Moreover, four nonlinear controllers such as the Fractional Order Terminal Sliding Mode Controller (FOTSMC), Integral Terminal Sliding Mode Controller (ITSMC), Double Integral Sliding Mode Controller (DISMC) and Integral Sliding Mode Controller (ISMC) have been proposed in this work for HCV infection control inside the human body. In order to control the amount of uninfected hepatocytes to its required maximum safe limit, controllers are designed for antiviral therapy in which the amount of virions and infected hepatocytes are tracked to zero. One control input is ribavirin which blocks virions production and the other is pegylated interferon (peg-IFN-α) that acts as reducing infected hepatocytes. By doing so, uninfected hepatocytes increase and achieve the required maximum safe limit. To prove the stability of the whole system, Lyapunov stability analysis is used in this work. Simulation results and comparative analysis are carried out by using MATLAB/Simulink. It can be depicted from the given results that the virions and infected hepatocytes are reduced to their required levels completely using FOTSMC and the Sustained Virologic Response (SVR) rate is also enhanced in it. It reduces the treatment period as compared to previous strategies introduced in the literature and also system behaves very nicely even in the presence of un-modeled disturbances.

Adaptive boundary layer double integral sliding mode controller design for leukemia therapy

SummaryPresence of leukocytes in huge amount in the bone marrow and blood causes blood cancer or leukemia. In leukemia, number of white blood corpuscles in blood increases rapidly. Chemotherapy treatment is the most useful treatment of leukemia. Although chemotherapy treatment can reduce the cancer cells effectively, it destroys the healthy cells of the body as well. Therefore, it is essential to develop a proper control structure to use the chemotherapy agent effectively to reduce the cancer cells and to keep the normal cells within specified limit. An adaptive boundary layer double integral sliding mode controller is designed in this article for treatment of acute leukemia using chemotherapy. The objective of the designed controller is to control the chemotherapy agent in such a way that the amount of leukemic cell become zero and at the same time, the number of healthy cells should be retained at a desired level. The stability of the designed controller is verified using a Lyapunov function. The consequences of chemotherapy treatment on both natural cells and cancer cell using the designed controller is observed in both monotonic and non‐monotonic therapy function. A comparative analysis is also carried out between the designed controller and some existing controller to verify the effectiveness of the proposed controller.

Variable Structure-Based Control for Dynamic Temperature Setpoint Regulation in Hospital Extreme Healthcare Zones

In critical healthcare units, such as operation theaters and intensive care units, healthcare workers require specific temperature environments at different stages of an operation, which depends upon the condition of the patient and the requirements of the surgical procedures. Therefore, the need for a dynamically controlled temperature environment and the availability of the required heating/cooling electric power is relatively more necessary for the provision of a better healthcare environment as compared to other commercial and residential buildings, where only comfortable room temperature is required. In order to establish a dynamic temperature zone, a setpoint regulator is required that can control the zone temperature with a fast dynamic response, little overshoot, and a low settling time. Thus, two zone temperature regulators have been proposed in this article, including double integral sliding mode control (DISMC) and integral terminal sliding mode control (ITSMC). A realistic scenario of a hospital operation theater is considered for evaluating their responses and performance to desired temperature setpoints. The performance analysis and superiority of the proposed controllers have been established by comparison with an already installed Johnson temperature controller (JTC) for various time spans and specific environmental conditions that require setpoints based on doctors’ and patients’ desires. The proposed controllers showed minimal overshoot and a fast settling response, making them ideal controllers for operation theater (OT) zone temperature control.

Robust nonlinear control of regenerative fuel cell, supercapacitor, battery and wind based direct current microgrid

Due to their simple structure and tremendous energy efficiency, direct current (DC) microgrids are becoming popular. The recent transition in power generation and consumption is based on the integration of renewable energy sources using DC microgrids. To facilitate this integration, a multi-source DC microgrid structure with five different sources including hybrid photoelectrochemical and photovoltaic (HPEV) cell, fuel cell, supercapacitor, battery and wind is presented in this paper. All the sources are linked to the DC bus via DC–DC power converters. Maximum power points for HPEV and wind have been obtained using artificial neural network. Nonlinear sliding mode controller, integral sliding mode controller, double integral sliding mode controller and super-twisting sliding mode controller have been presented for the output voltage regulation of the power sources. Global asymptotic stability of the framework has been verified using Lyapunov stability analysis. For load-generation balance, energy management system based on fuzzy logic has been devised. The proposed nonlinear controllers have been simulated and compared using MATLAB/Simulink®. Real-time hardware in the loop (HIL) experiment has been performed on the C2000 Delfino Microcontroller F28379D Launchpad for the validation of the proposed nonlinear controllers framework and compared with simulation results to validate the performance of the designed system.

Capability Exploration of Extended-State Observer-Based Control Under the Uncertain Case of Disturbance and Actuator Saturation

Considering a class of nonlinear systems subject to actuator saturation and uncertain control input, this article explored the control capability of an extended-state observer-based active disturbance rejection controller in the presence of disturbances and uncertainties. First, the actuator saturation is handled with the convex hull in the extended-state observer-based control scheme, and an ellipsoid invariant set inside the domain of attraction for control systems is obtained using the Lyapunov method. Second, the enlargement problem of the invariant set is also studied, which illustrates that the convex hull of the ellipsoid invariant sets is also an enlargement invariant set. Finally, comprehensive comparisons with existing methods on a brushless dc motor demonstrate the stronger capability of the designed controller on disturbance rejection and actuator saturation. The results show that the disturbance offset and performance index (integrated time and absolute error and integral absolute error) are about half of the classical proportional–integral–derivative(PID) and double-integral sliding-mode control, or the disturbance rejection capability is about twice in this case.

Flower pollination global peak search algorithm for partially shaded solar photovoltaic system

Photovoltaic (PV) systems are required to function at their maximum power point (MPP) to fully utilize solar energy. Solar PV panels are configured with maximum power point tracking (MPPT) systems to enhance the generation and supply of the maximum available power. However, owing to external environmental factors and partial shading conditions (PSCs), the tracking process becomes complex. Conventional MPPT methods cannot always achieve the global MPP. Thus, an advanced metaheuristic MPPT scheme for PV systems, the flower pollination algorithm (FPA), is implemented in this study to find the best global duty cycle to obtain the maximum power output, and a Levy flight is utilized to enhance FPA convergence. The FPA MPPT model was established, and its performance was compared with the conventional, and some meta-heuristic-based MPPT techniques; perturb and observe (PO), incremental conductance (INC), particle swarm optimization (PSO), cuckoo search (CS), grey wolf optimization (GWO), genetic algorithm (GA), double integral sliding mode control (DISMC), and hill-climbing (HC). Different scenarios were considered for the simulation: partial shading, complex partial shading, long-width, and long-length partial shading, and different temperature conditions employing series and series-parallel PV array configurations. In addition, real-world field atmospheric irradiance data for Daejeon city is used for the study. In terms of efficiency, the FPA attains at most 83%–96% of the expected GMP from the PV array as compared with the other MPPT techniques in all scenarios considered. The adopted FPA obtained the following root mean square error (RMSE), mean relative error (MRE), and mean absolute error (MAE) values respectively for each Scenario as follows: Scenario I: RMSE: 0.0061, MRE: 0.0463, MAE: 6.0745e-06, Scenario II: RMSE: 0.0116, MRE: 0.0430, MAE: 1.0738e-05, Scenario III: RMSE: 0.0640, MRE: 0.206, MAE: 4.8239e-05, Scenario IV (varying temperature conditions): RMSE: 0.0062–0.0074, MRE: 0.0460–0.0548, MAE: 6.1333e-06 – 7.4922e-06. A unique sensitivity performance comparison analysis is done employing the power spectral analysis to validate the effectiveness of the adopted FPA to the other MPPT techniques. The FPA performs better than all the techniques in all scenarios in comparing their maximum power tracked, convergence speed and accuracy, system efficiency, and optimum statistical results attained.

Double-integral sliding mode control of the switched-inductor quasi-Z source boost converter

Compared with the traditional converter, the switching inductance quasi-Z source DC-DC boost converter has the characteristics of wide output voltage, small capacitor size and more reliable circuit. However, in the process of DC voltage boost, the system is prone to high startup impulse voltage, output voltage fluctuation, and other problems. Therefore, a double integral sliding mode control (DISMC) method is proposed. The control method takes the capacitance voltage error, the inductance current error and their sum of single integral and double integral as state variables, and derives the equivalent control law from the sliding mode surface. A Lyapunov function is constructed to analyze the existence conditions of DISMC method. And the effects of abrupt changes of input voltage, negative reference voltage and load power on transient oscillation, steady state error and overshoot of the system are analyzed. This control method solves the non-minimum phase problem of capacitor voltage, so as to improve the start-up performance of the controller and speed up the response of the system. Finally, the superiority and effectiveness of the control method are verified by simulation.

ANFIS based double integral sliding mode control for a grid-integrated hybrid power system

Hybrid Power System (HPS), an promising power generation strategy, has gained much popularity in recent years, thanks to its fundamental mechanism that taps the abundantly-available renewable energy sources. HPS comprises of a photovoltaic (PV) panel, a Battery Storage System (BSS) and a Solid Oxide Fuel Cell (SOFC). Here, PV is the chief power source whereas SOFC and BSS are used as backup generators to supply the required power in case when PV energy is deficient. All these sources, with distinct DC-DC converters, are integrated parallel to a same DC bus. A 3-phase Voltage Source Inverter (VSI) is used in this setup to convert DC voltage into AC. Different modes of operations have been demonstrated with conventional Sliding Mode Controller (SMC). The proposed Double Integral Sliding Mode Controller (DI-SMC)-trained Adaptive Neural Fuzzy Inference System (ANFIS) is utilized to enhance the performance and anti-interference ability of the hybrid system. Further, the HPS is also verified and validated in terms of achieving the preferred power supervision between DG sources, grid, and the load. Both modeling and control strategies of the hybrid scheme were simulated in MATLAB/Simulink. The aim of the proposed management scheme is to supply maximum-quality power to the grid under varying loading conditions and solar irradiance with FC state under consideration. Further, the management algorithm was also implemented to stabilize DC bus voltage under load variations.

Double integral sliding mode controller based bridge-type flux-coupling non-superconducting fault current limiter to protect DFIG-based multi-machine power system under transient-state

This paper proposes a double-integral sliding mode controller (DISMC) based bridge-type flux-coupling non-superconducting fault current limiter (BFC-NSFCL) to enhance the fault ride-through (FRT) capability of a DFIG-based wind farm connected to a multi-machine power system. At first, a complete modeling of the BFC-NSFCL is derived to understand its behavior during the normal and fault period more accurately. Then, the DISMC is designed based on that dynamic model obeying the double-integral theory, along with the single-integral sliding mode controller (SISMC) and non-integral sliding mode controller (NISMC) for comparison purpose. Finally, the performance of the DISMC in controlling the BFC-NSFCL has been analyzed and verified by comparing with that of the SISMC and the NISMC. The DISMC removes the chattering problems induced by the traditional SMCs and improves the transient performance by reducing the overshoot and steady-state error by implementing double-integral action. All the graphical and mathematical analyzes favor the DISMC based BFC-NSFCL under symmetrical and unsymmetrical fault (both temporary and permanent) scenarios.

Double integral sliding mode controller for wirelessly charging of fuel cell-battery-super capacitor based hybrid electric vehicle

In this paper, a double integral sliding mode controller is proposed for a hybrid electric vehicle comprised of the Fuel cell as the main energy source along with supercapacitor and battery as the auxiliary power source. To charge these energy storage units, an LCC-S compensation network-based wireless charging system has been proposed. An energy management system has been presented to efficiently distribute the power during the driving and charging modes. The stability of the proposed control structure has been verified by Lyapunov stability theory. The proposed control scheme has been verified by simulating the electric vehicle under the European extra-urban driving cycle in MATLAB/Simulink platform. To check the robustness and effectiveness, the proposed controller has been compared against PID and Lyapunov controllers. The real-time implementation of the proposed controller has been validated by controller hardware-in-loop experiments.

Robust Control for Buck dc to dc Converter by Using Double Integral Sliding Mode Control

In this paper, the performance concerning the sliding mode control approach for DC/DC converters is explored. The step-down kind switch regulator buck converter is used in many devices that utilize batteries as a source of power, such as laptops, electric vehicles and cell phones. Recently, it has been employed in renewable power processing, whereas it can gain maximum production power with high performance. In this work, a buck converter is developed with a proportional-integral-derivative sliding mode control (PID SMC) and a double complete sliding mode control (DISMC), and response for appropriate control parameters are determined. The performance parameters of the system have been tested and analyzed, demonstrating that DC to DC converter planned through the sliding mode control possess a speedy dynamic response and is so effective in many applications.

Simulation on staggered parallel boost converter with double integral sliding mode control

As a non-linear input power source, fuel cells have soft output characteristics, slow dynamic response, and short service life. In order to improve the service life of the fuel cell, this paper conducts a simulation study on an interleaved parallel boost circuit based on double integral sliding mode control. The interleaved parallel structure is used to reduce the input current ripple of the fuel cell, and the state space average equation is used for modeling. At the same time, the double integral sliding mode control can improve the dynamic performance of the Boost converter. A hysteresis control is added after the sliding mode control to weaken the chattering effect of the sliding mode control. Matlab simulations show that the interleaved parallel Boost circuit with double integral sliding mode control can control the output current ripple of the fuel cell within 1% and make the output voltage have good dynamic performance.

Design of a Nonlinear Stability Controller for Ground Vehicles Subjected to a Tire Blowout Using Double-Integral Sliding-Mode Controller

Design of a Nonlinear Stability Controller for Ground Vehicles Subjected to a Tire Blowout Using Double-Integral Sliding-Mode Controller

Variable Structure Based Control for the Chemotherapy of Brain Tumor

Brain Tumor is an unwanted mass when cells grow abnormally. It puts pressure on certain areas of the brain which dangerously affects its functioning. For severe tumors like malignant, surgery is not a good option because they do not have definite boundaries and are closely attached with the other healthy tissues of the brain. So chemotherapy is preferable in this case to avoid damaging the healthy cells. The primary intention of this research is to suggest a controller for drug injection so that the tumor cells may reach the desired reference value of zero. In this paper, variable structure based nonlinear control algorithms: sliding mode control, integral sliding mode control, double integral sliding mode control and super-twisting sliding mode controllers have been proposed to reduce the tumor cells, maintain a safe number of healthy cells, keep the immune cells above a certain value and ensure suitable amount of chemotherapy drug. Lyapunov based stability theory has been used to prove stability of SMC, ISMC, DISMC and ST-SMC. MATLAB/Simulink environment has been used to analyze the performance of the proposed controllers on the basis of chattering, rate of convergence, undershoot/overshoot etc. and on the basis of these results drug through most suitable controller is advised. Among the proposed controllers, due to its better convergence, reduced chattering and less amount of drug used, ST-SMC is suggested for the chemotherapy of brain tumor.

A Modified Double-Integral-Sliding-Mode-Controller for a Microgrid System With Uncertainty

Recently infiltration of large scale of microgrid systems into the power grid isrecorded. Among these systems, photovoltaic (PV) based microgrid systemsare more in demand due to its renewable, pollution free properties andabundantly available fuel. Grid integration of this microgrid system againenhanced its energy efficiency. But, dynamics of this PV based microgridsystem is highly nonlinear and uncertain in nature. It suffers from para-metric uncertainties. This kind of system can’t be controlled properly byconventional linear controllers. Sliding mode controller (SMC) is capableof controlling this kind of system with ease. However, SMC suffers from itsinherent chattering introduction in the system output waveform. To reduce thechattering from the output waveform, there is requirement of some modifica-tion in the existing SMC structure dynamics. This paper presents an extendedstate observer based double integral sliding mode controller (DISMC) for thisstudied system. By using DISMC, the chattering magnitude is diminishedgreatly. Parameter uncertainties of the system lead to some unknown controlstates. These unknown states are identified by the state observer. Therefore,the proposed controller is more efficient in reference tracking, disturbance rejection and robust stability. To test the efficacies of the proposed controller,results of the studied system with this controller are compared with that ofH∞ controller.

Robust non-linear control of a hybrid water pumping system based on induction motor

This contribution presents a non-linear control of a hybrid pumping system supplied with a photovoltaic generator and a battery. This system is employed for delivering a continuous volume of water whatever the climatic conditions. In the DC side, a boost converter is controlled with the indirect double integral sliding mode controller (DISMC) for maximum power point tracking (MPPT). The DISMC is suitable for MPPT because it gives a fast response and reduces the amplitude of power oscillations. Then, a bidirectional buck-boost converter is adopted to ensure the energy management between the battery and the DC-bus, and this converter is controlled with integral sliding mode control (ISMC) theory. The non-linear predictive control (NPC) is chosen to drive an induction motor (IM), the NPC is known by its fast dynamic and high capacity to reject disturbances. The hybrid system is modelled in MATLAB/Simulink software. During simulations, the DISMC-MPPT is compared with other techniques such as sliding mode controller (SMC) MPPT and integral SMC MPPT, the DISMC provides the best tracking performances under different irradiances. Moreover, the designed controller for the bidirectional converter regulates the DC-link voltage with better performances than the classical PI controller. Lastly, the NPC regulates the speed of the IM with high robustness.

Double Integral sliding mode control of Leukemia Therapy

Leukemia is a form of cancer caused by the presence of large number of leukocytes in the blood and bone marrow and is commonly known as cancer of blood and bone marrow. This form of cancer is responsible for the rapid production of abnormal white blood cells in the circulatory system. Chemotherapy is the most common treatment of cancer and generally kills the Leukemic as well as some normal cells. Three nonlinear controllers namely Sliding Mode Controller (SMC), Integral Sliding Mode Controller (ISMC) and Double Integral Sliding Mode Controller (DISMC) have been designed using the model of Acute Leukemia under the effect of Chemotherapy treatment. The effect of therapy on normal and Leukemic cells has been described by two therapy functions namely monotonic and non-monotonic therapy function. Monotonic therapy function is based on Michaelis–Menten equation in which the effect of therapy depends on the amount of therapeutic agent used whereas the non-monotonic therapy function has a threshold effect in which the effect of drug reaches maximum value at some point and then decreases after that point. The main objective of this research is to track the Leukemic cells to zero, track and retain normal cells to a safe number and ensure minimum safe application of total quantity of therapeutic agent during the therapy process. The system has been analyzed using Lyapunov based stability theory. The controllers have been simulated using Matlab/Simulink and their performance has been compared with each other on the basis of convergence of all states to their desired references and steady state accuracy.

Variable structure-based control of fuel cell-supercapacitor-battery based hybrid electric vehicle

• Fuel Cell-Supercapacitor-Battery based Hybrid Electric Vehicle ahas been considered. • Double Integral Sliding Mode non-linear controller for output voltage regulation of DC Bus in HEVs has been proposed. • Using Lyapunov Stability Theory, asymptotic stability of the proposed controller has been proved. • The comparison is done with other controllers in the literature has been given. Hybrid electric vehicles (HEVs) are getting attention due to their importance in the transport Industry. Clean energy generation and effective utilization is rapidly growing research area. Fuel cell based electric vehicles have many advantages over conventional vehicles. The fuel cell is a massive source of clean energy that overcomes the issues of conventional vehicles such as; global warming and high fuel cost. The hybrid energy storage system (HESS) of the proposed vehicle consists of three power sources; fuel cell (FC), battery, and a supercapacitor (SC) which are connected to the DC bus through the DC-DC power converters. DC bus is further connected to DC-AC inverter which is used to run the electric motor of vehicle. In this paper, three nonlinear controllers namely; Sliding Mode Controller (SMC), Integral sliding mode controller (ISMC) and Double integral sliding mode controller (DISMC) have been proposed to achieve the desired control objectives. The purpose of ISMC and DISMC is to eliminate the steady-state error and mitigate the chattering effect inherent in SMC. The main objectives of proposed controllers are; tracking of battery and supercapacitor currents to their reference values, voltage regulation of DC bus and the global stability of the system. The proposed controllers have then been simulated using MATLAB/Simulink to analyze their comparative performance. It is noted that DISMC could alleviate the steady-state error significantly.

A novel control strategy for mode seamless switching of PV converter in DC microgrid based on double integral sliding mode control

With the photovoltaic (PV) penetration increases in dc microgrid, the traditional PV converters with maximum power point tracking (MPPT) control, which are equivalent to current sources, can hardly meet the needs of coordinated operation. The PV converter should operate in both MPPT and constant voltage control (CVC) modes. When the operation mode changes, the PV converter needs to switch between current and voltage sources. Inevitably, the bus voltage instability would be caused. This paper presents a novel switching strategy for the smooth and seamless operation of the PV converter between MPPT and CVC modes. The PV converter under these two modes is always controlled as a voltage source, and its control variables are both the output voltage of PV arrays. When its operation mode changes from MPPT to CVC, a small offset signal based on DC bus voltage would be introduced to the reference voltage of inner loop of the PV converter, so as to shift the maximum power point (MPP) voltage. Meanwhile in the voltage inner loop, a double integral sliding mode controller (DISMC) is used to improve the performance and anti-interference ability of the PV converter. This method unifies MPPT and bus voltage adjustment strategy without any communication and changing any hardware structure and control parameters. When mode switching occurs, only the reference value of voltage inner loop would be slightly adjusted near the maximum photovoltaic power point, so the seamless transition for PV converter between the two modes can be ensured. Finally, the effectiveness of the mode seamless switching control strategy is demonstrated by the simulation and experimental tests.

Voltage and Current Regulations of Bidirectional Isolated Dual-Active-Bridge DC–DC Converters Based on a Double-Integral Sliding Mode Control

In this paper, a novel control scheme of the bidirectional isolated dual-active-bridge (DAB) dc–dc converters is proposed to regulate the output voltage and current, based on a sliding mode (SM) control. At first, a mathematical model of the DAB converter is expressed in a state-space form. Then, the output voltage and current controllers of the DAB converter are designed with the double-integral SM control theory, which is robust to the model uncertainty and disturbance. The proposed control method provides not only the zero steady-state error without any chattering but also the fast transient response for load variations and reference changes. The validity of the proposed control algorithm has been verified by simulation and experimental results for a 1.5-kW DAB converter.