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EN
In order to improve the accuracy and robustness of path following control for an Unmanned Surface Vehicle (USV) suffering from unknown and complex disturbances, a variable speed curve path following a control method based on an extended state observer was proposed. Firstly, the effect of the environmental disturbances on the USV is equivalent to an unknown and time-varying sideslip angle, and the sideslip angle is estimated by using the extended state observer (ESO) and compensated in the Line of Sight (LOS) guidance law. Secondly, based on the traditional LOS guidance law, the design of the surge velocity guidance law is added to enable the USV to self-adjust the surge velocity according to the curvature of the curve path, thus further improving the tracking accuracy. Finally, the heading and speed controller of the USV is designed by using a sliding mode control to track the desired heading and speed accurately, and then the path following control of the USV’s curve path is realised. Simulation results verify the effectiveness of the proposed method.
EN
In this work, we have developed a new 4-D dynamical system with hyperchaos and hidden attractor. First, by introducing a feedback input control into the 3-D Ma chaos system (2004), we obtain a new 4-D hyperchaos system with no equilibrium point. Thus, we derive a new hyperchaos system with hidden attractor. We carry out an extensive bifurcation analysis of the new hyperchaos model with respect to the three parameters. We also carry out probability density distribution analysis of the new hyperchaotic system. Interestingly, the new nonlinear hyperchaos system exhibits multistability with coexisting attractors. Next, we discuss global hyperchaos self-synchronization for the new hyperchaos system via Integral Sliding Mode Control (ISMC). As an engineering application, we realize the new 4-D hyperchaos system with an electronic circuit via MultiSim. The outputs of the MultiSim hyperchaos circuit show good match with the numerical MATLAB plots of the hyperchaos model. We also analyze the power spectral density (PSD) of the hyperchaos of the state variables using MultiSim.
EN
The case studied in this paper relates to the control of a system photovoltaic. As the output characteristic of a photovoltaic (PV) module is nonlinear and changes with solar irradiance and the load, its maximum power point (MPP) is not constant. Therefore, a (MPPT) technique is needed to draw peak power from the PV module to maximize the produced energy and voltage delivered by the PV system constant under varying conditions. In our study, we used two MPPT algorithms, the algorithm “Perturb and Observe” (P & O), then the algorithm “Increment of Conductance” (IncCond). For this, a control system is presented. The methods used for the simulation of this system are based on the use of a sliding mode control. Simulation results are presented to verify the simplicity, the stability and the robustness of this control technique against changes in weather conditions.
PL
Przypadek opisany w tym artykule dotyczy kontroli fotowoltaiki systemowej. Ponieważ charakterystyka wyjściowa modułu fotowoltaicznego (PV) jest nieliniowa i zmienia się wraz z natężeniem promieniowania słonecznego i obciążeniem, jego maksymalna wartość mocy (MPP) nie jest stała. Dlatego technika (MPPT) jest potrzebna do pobrania mocy szczytowej z modułu fotowoltaicznego w celu zmaksymalizowania wytworzonej energii i napięcia dostarczanego przez stałą systemu PV w różnych warunkach. W naszym badaniu wykorzystaliśmy dwa algorytmy MPPT, algorytm "Perturb and Observe" (P & O), a następnie algorytm "Increment of Conductance" (IncCond). W tym celu przedstawiono system kontroli. Metody użyte do symulacji tego systemu opierają się na zastosowaniu sterowania w trybie ślizgowym. Przedstawiono wyniki symulacji, aby zweryfikować prostotę, stabilność i odporność tej techniki sterowania przed zmianami warunków pogodowych.
PL
Strategie sterowania ślizgowego są cenione za swoją całkowitą niewrażliwość na klasę zakłóceń i niepewności modelu. Uzyskanie tej właściwości jest możliwe przez sprowadzenie punktu opisującego dynamikę układu na pewną hiperpowierzchnię przełączeń zdefiniowaną w przestrzeni stanów. W początkowym etapie sterowania, w którym punkt opisujący zbliża się do tej hiperpowierzchni, układ pozostaje wrażliwy na zakłócenia, co utrudnia projektowanie skutecznych strategii sterowania ślizgowego. Aby zapewnić odporność układu na zakłócenia i niepewności modelu na wszystkich etapach procesu sterowania liczni autorzy zaproponowali zastosowanie ruchomych hiperpowierzchni przełączeń. Celem niniejszego artykułu przeglądowego jest przedstawienie najważniejszych osiągnięć z zakresu sterowania ślizgowego z wykorzystaniem takich hiperpowierzchni. Omówione są pionierskie prace proponujące zastosowanie ruchomych hiperpowierzchni przełączeń oraz przedstawione są metody ich projektowania. Następnie podkreślone są najważniejsze osiągnięcia z zakresu sterowania ślizgowego wykorzystującego ruchome hiperpowierzchnie przełączań zarówno dla układów ciągłych jak i dyskretnych.
EN
Sliding mode control strategies are valued for their total insensitivity to the class of disturbances and uncertainty of the model. Obtaining this property is possible by bringing a point describing the dynamics of the system to a certain switching hypersurface defined in the state space. At the initial stage of control, where the description point approaches this hypersurface, the system remains sensitive to interferences, which hinders the design of effective sliding mode control strategies. To ensure the system’s resistance to interference and model uncertainty at all stages of the control process, many authors proposed the use of mobile switching hypersurfaces. The purpose of this review article is to present the most important achievements in the area of sliding mode control using such hypersurfaces. Discussed are pioneering works proposing the use of mobile switching hypersurfaces and methods of their design are presented. Next, the most important achievements in the area of sliding mode control using movable switching hypersurfaces for both continuous and discrete systems are highlighted.
EN
A description is given of an application of the sliding mode control (SMC) for stabilizing the static and dynamic characteristics of an anti-aircraft missile. The solution provides effective separation of the control process from the dynamics of the missile airframe. In the equivalent part of the stabilization system, a linear-quadratic regulator (LQR) is considered, and an analytical method of selecting the weighting elements of the gain matrix is proposed. This eliminates the need for an iterative solution of the Riccati equation. A nonlinear switching component is introduced into the control signal to provide smoothness of the system response. In simulation tests, the proposed solution was evaluated against selected quantity indices. The paper ends with observations and conclusions.
EN
The drive system of a switched reluctance motor (SRM) is a nonlinear one with coupling between the rotor position, inductance, and flux linkage. Moreover, the system parameters change with the external environment such as temperature, humidity, and pressure. At the same time, uncertain factors including friction, torque fluctuation, and external interference in the system, reduce system stability and reliability. To effectively improve the influence of uncertain factors on the performance of an SRM system, this study proposes an auxiliary sliding position tracking method, under the condition of limited control input. First, the mathematical model of the system was established according to the structure and characteristics of an SRM.Second, an auxiliary sliding mode position tracking controller was designed by constructing the auxiliary system and utilizing the sliding mode control theory. Finally, the effectiveness and superiority of the proposed method were verified through comparison with proportional integral differential (PID) control and the traditional sliding mode control using simulation. Results demonstrate that under limited control input, the auxiliary sliding position tracking control method still delivers rapid and error-free tracking of the position and speed for the change of model parameters. The recommended scheme has a response time 2.9 times shorter than that of PID control. Furthermore,the steady-state errors of the PID control position and speed are 0.66 rad and 1.62 rad/s, respectively. The control input of the traditional sliding mode control has greater chattering than the proposed method. When the system has interference, the designed method under the condition of limited control in-put can achieve the desired tracking command within 1.7 s. The steady-state error is 0.0044 rad, and the steady-state accuracy of the developed scheme is 10.3 times higher than that of PID control. Therefore, the proposed method enjoys both high position tracking accuracy and strong robustness to external disturbances.
EN
This paper deals with a possible approach to controlling marine fish stocks using the prey‐predator model described by the Lotka‐Volterra equations. The control strategy is conceived using the sliding mode control (SMC) approach which, based on the Lyapunov theorem, offers the possibility to track desired functions, thus guaranteeing the stability of the controlled system. One of the most important aspects of this model is the identification of some parameters which characterizes the model. In this work two cascaded and Extended Kalman Filters (EKFs) are proposed to estimate them in order to be utilized in SMC. This approach can be used for sustainable management of marine fish stocks: through the developed algorithm, the appropriate number of active fishermen and the suitable period for fishing can be determined. Computer simulations validate the proposed approach.
EN
This paper deals with the design of an adaptive-fuzzy-PD-Sliding mode controller to achieve stabilization of a quadrotor aircraft in the presence of wind disturbance. Firstly, the dynamic system modeling is carried out using Euler-Lagrange formalism. Then, an adaptive PD-sliding mode control system with an integral-operation switching surface is investigated for quadrotor desired trajectory tracking. Finally, an adaptive fuzzy-PD-sliding mode controller is proposed to achieve control objectives and system stabilization where the fuzzy logic system used to dynamically control parameters settings of the PD-sliding mode equivalent control law. Effectiveness and robustness of the proposed control scheme is verified through simulation results taking into account external disturbances. The simulation results of a quadrotor aircraft control with the proposed controller demonstrate the high performance during flight such as null tracking error and robustness in the presence of external disturbances.
EN
In the hybrid multiple H-bridge topology of beam supply, the load change of a DC/DC full-bridge converter can greatly affect the output voltage during onsite operation. An improved sliding mode control (SMC) strategy is thus proposed in this paper, where the rate of switching control is added to the law of system equivalent control to create a law that can realize a complete sliding mode control. Considering the special operating conditions of the load can have an influence on the performance of the controller, the impact of uncertainty existing in onsite conditions is suppressed with the proposed strategy utilized. The validity of the proposed strategy, finally, is verified by simulation, which proves the outperformance of the system in both robustness and dynamics.
EN
In order to control joints of manipulators with high precision, a position tracking control strategy combining fractional calculus with iterative learning control and sliding mode control is proposed for the control of a single joint of manipulators. Considering the coupling between joints of manipulators, a fractional-order iterative sliding mode crosscoupling control strategy is proposed and the theoretical proof of its progressive stability is given. The paper takes a two-joint manipulator as the research object to verify the control strategy of a single-joint manipulator. The results show that the control strategy proposed in this paper makes the two-joint mechanical arm chatter less and the tracking more accurate. The synchronous control of the manipulator is verified by a three-joint manipulator. The results show that the angular displacement adjustment times of the threejoint manipulator are 0.11 s, 0.31 s and 0.24 s, respectively. 3.25 s > 5 s, 3.15 s of a PD cross-coupling control strategy; 2.85 s, 2.32 s, 4.22 s of a PD iterative cross-coupling control strategy; 0.14 s, 0.33 s, 0.28 s of a fractional-order sliding mode cross-coupling control strategy. The root mean square error of the position error of the designed control strategy is 6.47 × 10−6 rad, 3.69 × 10−4 rad, 6.91 × 10−3 rad, respectively. The root mean square error of the synchronization error is 3.96×10−4 rad, 1.36×10−3 rad, 7.81×10−3 rad, superior to the other three control strategies. The results illustrate the effectiveness of the proposed control method.
EN
A new 4-D dynamical system with hyperchaos is reported in this work. It is shown that the proposed nonlinear dynamical system with hyperchaos has no equilibrium point. Hence, the new dynamical system exhibits hidden hyperchaotic attractor. An in-depth dynamic analysis of the new hyperchaotic system is carried out with bifurcation transition diagrams, multistability analysis, period-doubling bubbles and offset boosting analysis. Using Integral Sliding Mode Control (ISMC), global hyperchaos synchronization results of the new hyperchaotic system are described in detail. Furthermore, an electronic circuit realization of the new hyperchaotic system has been simulated in MultiSim software version 13.0 and the results of which are in good agreement with the numerical simulations using MATLAB.
EN
Although the multitude benefit of wind power, the randomness of wind speed and the fluctuations of wind power are the most disadvantages of wind energy. So, for more efficiency and better performances, wind rotor must be driven at specific optimal rotational speed under each particular wind speed. Therefore, to extract the maximum power from wind turbine, a Maximum Power Point Tracking (MPPT) controller is required. In this paper, modeling of wind energy conversion system WECS using tip speed ratio (TSR) MPPT controller using PID controller tuned by genetic algorithm is investigated. The wind energy conversion is based on a doubly-fed induction generator (DFIG), which it is controlled by robust sliding mode control technique using a generator of 3.6 MW . The obtained results are presented and analyzed, where the performances of both proposed control strategies (MPPT based PID-GA, sliding mode control) have been shown.
PL
W pracy przedstawiono system energii wiatrowej wykorzystujący sterownik śledzący szcztową prędkość . W sterowniku zastosowano regulator PID strojony z wykorzystaniem algorytmu generycznego. Jako generator wykorzystano układ DFIG sterowany za pośrednictwem sterownika ślizgowego.
EN
Payload transportation with UAV’s (Unmanned Aerial Vehicles) has become a topic of interest in research with possibilities for a wide range of applications such as transporting emergency equipment to otherwise inaccessible areas. In general, the problem of transporting cable suspended loads lies in the under actuation, which causes oscillations during horizontal transport of the payload. Excessive oscillations increase both the time required to accurately position the payload and may be detrimental to the objects in the workspace or the payload itself. In this article, we present a method to control a quadrotor with a cable suspended payload. While the quadrotor itself is a nonlinear system, the problem of payload transportation with a quadrotor adds additional complexities due to both input coupling and additional under actuation of the system. For simplicity, we fix the quadrotor to a planar motion, giving it a total of 4 degrees of freedom. The quadrotor with the cable suspended payload is modelled using the Euler-Lagrange equations of motion and then partitioned into translation and attitude dynamics. The design methodology is based on simplifying the system by using a variable transformation to decouple the inputs, after which sliding mode control is used for the translational and pendulum dynamics while a feedback linearizing controller is used for the rotational dynamics of the quadrotor. The sliding mode parameters are chosen so stability is guaranteed within a certain region of attraction. Lastly, the results of the numerical simulations created in MATLAB/Simulink are presented to verify the effectiveness of the proposed control strategy.
EN
This study presents a new, reference trajectory based sliding mode control strategy for disturbed discrete time dynamical systems. The desired trajectory, which is generated externally according to an existing switching type reaching law, determines the properties of the emerging sliding motion of the system. It is proved that an appropriate choice of the trajectory generator parameters ensures the existence of the quasi-sliding motion of the system according to the definition by Gao et al. (1995) in spite of the influence of disturbances. Moreover, the paper shows that the application of the desired trajectory based reaching law results in a significant reduction in the quasi-sliding mode band width and errors of all state variables. Therefore, in comparison with Gao’s control method, the system’s robustness is increased. The paper also presents an additional modification of the reaching law, which guarantees a further reduction in the quasi-sliding mode band in the case of slowly varying disturbances. The results are confirmed with a simulation example.
EN
A sliding mode controller for the photovoltaic pumping system has been proposed in this paper. This system is composed of a?photovoltaic generator supplying a?three-phase permanent magnet synchronous motor coupled to a?centrifugal pump through a?three-phase voltage inverter. The objective of this study is to minimise the number of regulators and apply the sliding mode control by exploiting the specification of the field oriented control scheme (FOC). The first regulator is used to force the photovoltaic generator to operate at the maximum power point, while the second is used to provide the field oriented control to improve the system performance.The whole system is analysed and its mathematical model is done. Matlab is used to validate the performance and robustness of the proposed control strategy.
EN
The chaotic phenomena of coronary artery systems are hazardous to health and may induce illness development. From the perspective of engineering, the potential harm can be eliminated by synchronizing chaotic coronary artery systems with a normal one. This paper investigates the chaos synchronization problem in light of the methodology of sliding mode control (SMC). Firstly, the nonlinear dynamics of coronary artery systems are presented. Since the coronary artery systems suffer from uncertainties, the technique of derivative-integral terminal SMC is employed to achieve the chaos synchronization task. The stability of such a control system is proven in the sense of Lyapunov. To verify the feasibility and effectiveness of the proposed method, some simulation results are illustrated in comparison with a benchmark.
EN
This paper presents a robust control technique for small-scale unmanned helicopters to track predefined trajectories (velocities and heading) in the presence of bounded external disturbances. The controller design is based on the linearized state-space model of the helicopter. The multivariable dynamics of the helicopter is divided into two subsystems, longitudinallateral and heading-heave dynamics respectively. There is no strong coupling between these two subsystems and independent controllers are designed for each subsystem. The external disturbances and model mismatch in the longitudinal-lateral subsystem are present in all (matched and mismatched) channels. This model mismatch and external disturbances are estimated as lumped disturbances using extended disturbance observer and an extended disturbance observer based sliding mode controller is designed for it to counter the effect of these disturbances. In the case of heading-heave subsystem, external disturbances and model mismatch only occur in matched channels so a second order sliding mode controller is designed for it as it is insensitive to matched uncertainties. The control performance is successfully tested in Simulink.
EN
The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.
EN
The paper addresses an important issue in surface vessel motion control practice that the ship dynamics and sailing performance can be affected by speed loss. The vessel speed is significantly decreased by the added resistance generated by waves. An adaptive sliding mode course keeping control design is proposed which takes into account uncertain ship dynamics caused by forward speed variations, while avoiding performance compromises under changing operating and environmental conditions. The sliding mode control provides robust performance for time-varying wave disturbances and time-varying changes in ship parameters and actuator dynamics. After combining the unknown but bounded system uncertainties, the design of the adaptation law is obtained which is based on the Lyapunov’s direct method. Simulations on a ship with two rudders illustrate the effectiveness of the proposed solution.
20
Content available remote Porównanie wybranych algorytmów sterowania napędem PMSM w sterowaniu nadążnym
PL
W niniejszym artykule przedstawiono porównanie czterech regulatorów podczas zadania nadążania za zadaną trajektorią. Obiektem symulacji jest napęd z silnikiem PMSM, na którego wale umieszczono dodatkowo masę bezwładną oraz masę skupioną, poruszającą się promieniście. Regulator w żaden sposób nie jest informowany o położeniu masy skupionej. Dodatkowo na układ oddziałuje tarcie, które również nie zostało zamodelowane. Porównano ze sobą regulator PID, regulator ślizgowy w postaci klasycznej, quasi-ślizgowy oraz supertwisting. Na końcu wyniki przedstawiono w tabeli.
EN
This paper presents comparison of four selected tracking control algorithms. The simulated plant is a PMSM drive with additional well-balanced inertia load and a point mass, which is moving radially. The controller has no information about position of the point mass. Moreover, friction is present in the plant, but it is unmodelled in the controller. PID, classical sliding mode, quasi-sliding mode and super-twisting controllers are compared. The paper ends with the table of advantages and disadvantages of investigated control algorithms.
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