Papers by Keyword: Sliding Mode Control

Abstract: The application of photovoltaic (PV) system in different sectors increases dramatically since it is clean, sustainable, and easy to maintain. However, PV systems have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP), which depends on environmental factors like temperature and irradiation. Maximum power point tracking (MPPT) is crucial for PV power systems to consistently extract the maximum power from solar panels as it optimizes power output under varying conditions. In this paper, a standalone PV-powered water pumping system is designed for Bahir Dar University Health Science College. Then fuzzy sliding mode control (FSMC) is designed for MPPT. The proposed controller is simulated in MATLAB/ SIMULINK and the controller's performance for optimizing the system's power output under different environmental and load conditions is evaluated. The effectiveness of the proposed MPPT algorithm is validated by comparing its performance with fuzzy logic control (FLC) and sliding mode control (SMC). Based on the simulation result FSMC has an MPPT efficiency of 99.13% compared with 80.21% in FLC and 97.81% in SMC.

Abstract: Renewable energy sources, such as photovoltaic, fuel cell and wind energy are becoming a sustainable alternative to non-renewable sources like fossil fuel. However, to integrate these energies into the grid, power electronic converters plays major role due to their power conditioning capability, reliability and effectiveness. In this paper, design, modeling and analysis of a DC-DC boost converter with robust controlling technique, fuzzy sliding mode controlling strategy has been developed and a brief comparison has been performed with a sliding mode controller and a clasical PID controller which employed both current and a voltage control loop. The system is designed to achieve a fast dynamic response, zero steady-state error, and satisfactory stability. To realize that a detailed mathematical derivation of sliding mode fuzzy logic controller and a linearized small signal model of the power electronic converter around its DC steady state operating point is performed. Finally, in order to evaluate the designed system, a software simulation based on MATLAB/ Simulink environment is developed and results of the simulation shows the effectiveness of the proposed techniques.

Abstract: The paper presents active and semi-active vibration reduction systems applying sliding mode control systems. Calculations were completed for a laboratory system with two masses moving in a vertical direction. Support of the system is connected with the moving part of the exciter. The proposed system may be a simple model of many vibroisolated objects. In order to apply the control system of vibrations in the suspension of the upper mass, an actuator was implemented together with a spring. The role of the actuator was played by a linear inductive motor.Active and semi-active sliding mode controllers are proposed for the vibration reduction system. Theoretical analysis focused on applying of the sliding mode control in this system was carried out and, moreover, conditions to be met by the controllers were determined. The results of simulations and experiments are presented in tables and plots.

Abstract: Numerical modeling and a tracking control of angular velocity of a rotor measured in the assumed sliding contact bearing subject to a discontinuous dynamical loading has been performed in this contribution. A contact interface in the direct current motor’s sleeve bearing has been treated as a dynamical system with dry friction, including a few sources of the stick-slip and creep-slip effects. The object of control is subject to an irregularly changing torque generated by another discontinuous dynamical system with friction. The loading comes from a block-on-belt model of a conveyer system with intensification of friction force, which has been elastically coupled with the direct current rotor’s shaft by means of the transmission belt. Therefore, the dynamic loading of the DC motor changes because of time-varying linear velocity of two belts. If such additional torque oscillates while the rotational velocity of the motor’s shaft is small due to a requirement, then it significantly affects the entire system’s dynamics producing stronger nonlinear response of the motor’s speed.

Abstract: DC servo systems which are utilized in many industries require efficient and robust control strategies for achieving specific duties accurately. An integral sliding mode control (ISMC) is designed for position control of DC servo-driven conveyor system in this work. The ISMC which maintains the robustness, linearization and systematic design procedure of the conventional sliding modes is aimed to solve robust position control problem under load uncertainties. Performance and robustness of the ISMC are compared with the PID controller. Numerical and experimental results are presented to demonstrate the validity, feasibility and effectiveness of the designed control technique.

Abstract: The sliding mode control approach based on double power exponential reaching law is proposed for the hydraulic servo system. With the example of the hydraulic servo system in the lab, the mathematic model is established and the new controller is presented and simulated. Simulation results show that: the proposed approach has high track precision, fast response, small chattering and ensures dynamic quality of the system.

Abstract: This paper considers the sliding mode control for discrete uncertain system with time delay. First, the discrete uncertain system is transformed into a simplified form; then some sufficient conditions of guaranteeing the asymptotic stability of the uncertain system are given; finally the effectiveness of the proposed method is confirmed by the simulations.

Abstract: This Paper deals with the sliding mode control of a class of uncertain Markov switched systems. By using linear transformation, the system is transformed into standard type. A sufficient condition of the existence of a sliding mode dynamics is derived, and an explicit parameterization of desired sliding surface is also given. A sliding mode controller is then designed to guarantee exponential stability of the overall switched closed-loop system. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approaches.

Abstract: The switched mode dc-dc converters are some of the most widely used power electronics circuits because of high conversion efficiency and flexible output voltage. Many methods have been developed for the control of dc-dc converters. This paper deals with design of controller for dc-dc buck converter using various control techniques. The first two control techniques are based on classical or linear control methods i.e. PI and PID control, while the other two control technique are based on non linear control method i.e. Sliding Mode Control (SMC) and Sliding Mode Proportional Integral Derivative Control (SMC-PID). The output voltage and the inductor current of the applied control techniques are analyzed and compared in transient and steady state region. Also the robustness of the buck converter system is tested for load changes and input voltage variations. Matlab/Simulink is used for the simulations. The detailed simulation results are presented, which compare the performance of the designed controllers for various cases. The results show that the non linear control for DC/DC Buck converter proves to be more robust than linear control especially when dynamic tests are applied.

Abstract: In this paper, a vehicle stability control system is proposed to improve vehicle comfort, handling and stability. The control system includes reference model, DYC controller and Distributer. Reference model is used to obtain the desired yaw rate. DYC controller determines the desired yaw moment by means of sliding-mode technique. Distributer, based on maneuverability and comfort, distributes driving torque or braking torque according to the desired yaw rate. Simulation result shows that the proposed control algorithm can improve vehicle handling and stability effectively.