Terminal sliding mode control strategy design for second-order nonlinear system

This study mainly focuses on the terminal sliding mode control (TSMC) strategy design, including an adaptive terminal sliding mode control (ATSMC) and an exact-estimator-based terminal sliding mode control (ETSMC) for second-order nonlinear dynamical systems. In the ATSMC system, an adaptive bound estimation for the lump uncertainty is proposed to ensure the system stability. On the other hand, an exact estimator is designed for exact estimating system uncertainties to solve the trouble of chattering phenomena caused by a sign function in ATSMC law in despite of the utilization of a fixed value or an adaptive tuning algorithm for the lumped uncertainty bound. The effectiveness of the proposed control schemes can be verified in numerical simulations.<br /

Position control of induction motor using indirect adaptive fuzzy sliding mode control

Author name used in this publication: K. W. E. ChengAuthor name used in this publication: H. F. HoVersion of RecordPublishe

Development of Fuzzy Applications for High Performance Induction Motor Drive

This chapter develops a sliding mode and fuzzy logic-based speed controller, which is named adaptive fuzzy sliding-mode controller (AFSMC) for an indirect field-oriented control (IFOC) of an induction motor (IM) drive. Essentially, the boundary layer approach is the most popular method to reduce the chattering phenomena, which leads to trade-off between control performances, and chattering elimination for uncertain nonlinear systems. For the proposed AFSMC, a fuzzy system is assigned as the reaching control part of the fuzzy sliding-mode controller so that it improves the control performances and eliminates the chattering completely despite large and small uncertainties in the system. A nonlinear adaptive law is also implemented to adjust the control gain with uncertainties of the system. The adaptive law is developed in the sense of Lyapunov stability theorem to minimize the control effort. The applied adaptive fuzzy controller acts like a saturation function in the thin boundary layer near the sliding surface to guarantee the stability of the system. The proposed AFSMC-based IM drive is implemented in real-time using digital signal processor (DSP) board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed AFSMC-based IM drive at different operating conditions such as load disturbance, parameter variations, etc

Hybrid Speed Controller Design Based on Sliding Mode Controller Performance Study for Vector Controlled Induction Motor Drives

The discontinuous control of the sliding mode control (SMC) law causes chattering phenomenon in system trajectories (the oscillation around the desired value), which results in various unwanted effects such as current harmonics and torque ripples. Therefore, this study aims to investigate the performance of a sliding mode speed controller for a three-phase induction motor (IM) controlled by a rotor flux orientation technique to obtain optimum performance. The study results show that the experimental control gains found in the control law have a clear effect on limiting chattering and the system response speed. According to the study results, a hybrid controller is designed based on the fuzzy logic control (FLC) approach to optimally tune these gains. The designed hybrid controller is verified by experimental approximation of simulations using Matlab/Simulink. The simulation results show that the hybrid controller reduces the chattering phenomenon and improves the system’s dynamic performance

State-dependent sliding mode control for three-phase induction motor drives

This research focuses on investigation and evaluation of the robust speed control for threephase induction motor. A sliding mode control, which offers great potential to deal with uncertainties such as parameter variation and external load disturbances, is examined. The main obstacle of conventional sliding mode control is caused by discontinuous function of high control activity which is known as chattering phenomenon. In this research, this chattering phenomenon is significantly reduced by a newly developed algorithm. A fast sigmoid function with varying boundary layer algorithm is designed as a state-dependent to replace the discontinuous function in conventional sliding mode control as well as to avoid steady state error compare with the use of fixed boundary layer. It is known that the switching gain of sliding mode control is proportional to the chattering level, and normally a large switching gain is applied to handle the uncertainties. This research proposes a state-dependent sliding mode control which is the switching gain is proportional to the sigmoid function of the sliding mode controller. As a result, the boundary layer and the switching gain will change depending on uncertainties of the motor drives system. In this research, the induction motor is controlled by vector control strategy, using indirect field orientation and Space Vector Pulse Width Modulation technique. Simulation result have proved that the proposed state-dependent sliding mode control was able to deal with external load disturbances as well as effectively free from chattering phenomenon compared to conventional sliding mode control. Finally, experimental investigation is performed in order to confirm the theoretical and simulation findings. The proposed algorithm and the vector control strategy are developed in digital signal processing board. The experimental results have confirmed that the state-dependent sliding mode control is superior with regard to external load disturbances and variation in the reference speed setting when compared to PI speed control and conventional sliding mode control

Application of Sliding Mode Control in Indirect Field Oriented Control (IFOC) for Model Based Controller

Indirect Field Oriented Control (IFOC) is one of the vector control methods that can be applied to induction motor in the industrial world rather than Direct Field Oriented Control (DFOC) because of the flux is obtained from the formulation. However, IFOC can not guarantee the robustness and stability of the systems. Stability analysis such as Lyapunov Stability Theory can be used to make the system stable but not the robustness. Model based controller that can guarantee the stability and robustness such as sliding mode control (SMC) and fuzzy needs to be added in IFOC system to achieve proportional response system. Robust current regulator using sliding mode control was designed in this paper from state space model for model based controller. In transient response and under disturbance SMC shows better performance than PID in rising time and robustness at rotor speed and stator current

Real Time Implementation of Fuzzy Adaptive PI-sliding Mode Controller for Induction Machine Control

In this work, a fuzzy adaptive PI-sliding mode control is proposed for Induction Motor speed control. First, an adaptive PI-sliding mode controller with a proportional plus integral equivalent control action is investigated, in which a simple adaptive algorithm is utilized for generalized soft-switching parameters. The proposed control design uses a fuzzy inference system to overcome the drawbacks of the sliding mode control in terms of high control gains and chattering to form a fuzzy sliding mode controller. The proposed controller has implemented for a 1.5kW three-Phase IM are completely carried out using a dSPACE DS1104 digital signal processor based real-time data acquisition control system, and MATLAB/Simulink environment. Digital experimental results show that the proposed controller can not only attenuate the chattering extent of the adaptive PI-sliding mode controller but can provide high-performance dynamic characteristics with regard to plant external load disturbance and reference variations.

Adaptive proportional-integral fuzzy logic controller of electric motor drive

This paper presents the indirect field vector control of induction motor (IM) which is controlled by an adaptive Proportional-Integral (PI) speed controller. The proposed solution can overcome the rotor resistance variation, which degrades the performance of speed control. To solve this drawback, an adaptive PI controller is designed with gains adaptation based on fuzzy logic in order to improve the performances of IM with respect to parameters variations, particularly the rotor resistance (Rr). The proposed control algorithm is validated by simulation tests. The obtained results show the robustness towards the load torque disturbances and rotor resistance variation of the adaptive Proportional-Integral fuzzy logic control with respect to classical PI control, and adaptive control based on rotor resistance observer

A New Induction Motor Adaptive Robust Vector Control based on Backstepping

In this paper, a novel approach to nonlinear control of induction machine, recursive on-line estimation of rotor time constant and load torque are developed. The proposed strategy combines Integrated Backstepping and Indirect Field Oriented Controls. The proposed approach is used to design controllers for the rotor flux and speed, estimate the values of rotor time constant and load torque and track their changes on-line. An open loop estimator is used to estimate the rotor flux. Simulation results are presented which demonstrate the effectiveness of the control technique and on-line estimation