An Improved Sliding Mode Differentiator Combined with Sliding Mode Filter for Estimating First and Second-order Derivatives of Noisy Signals

Gyuho Byun,Ryo Kikuuwe 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.12

This paper proposes a new sliding mode differentiator combined with a sliding mode filter for estimating first and second-order derivatives of noisy signals. The proposed differentiator can be seen as a version of Slotine et al.’s sliding mode observer extended with an additional non-Lipschitz property, which is intended to realize a faster reaching to the sliding mode. It behaves as a noise-reduction filter that is composed of first, second and third-order low-pass filter in the sliding mode, but also employs the filter that is composed of second, third and fourth-order low-pass filter out of the sliding mode. Moreover, the differentiator effectively removes impulsive noises by combining a sliding mode filter and its discrete-time implementation is based on the implicit (backward) Euler discretization, which does not result in chattering and realizes the exact sliding mode. Experiments show that the proposed algorithm has a better balance between the noise attenuation and small phase lag than the linear-filtered Euler differentiation and previous sliding mode differentiators. It was validated through experiments using optical encoder signals of industrial robots.

Design and Implementation of an Adaptive Sliding-Mode Observer for Sensorless Vector Controlled Induction Machine Drives

Yanqing Zhang,Zhonggang Yin,Jing Liu,Xiangqian Tong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

An adaptive sliding-mode observer for speed estimation in sensorless vector controlled induction machine drives is proposed in this paper to balance the dilemma between the requirement of fast reaching transient and the chattering phenomenon reduction on the sliding-mode surface. It is well known that the sliding-mode observer (SMO) suffers from the chattering phenomenon. However, the reduction of the chattering phenomenon will lead to a slow transient process. In order to balance this dilemma, an adaptive exponential reaching law is introduced into SMO by optimizing the reaching way to the sliding-mode surface. The adaptive exponential reaching law is based on the options of an exponential term that adapts to the variations of the sliding-mode surface and system states. Moreover, the proposed sliding-mode observer considering adaptive exponential reaching law, which is called adaptive sliding-mode observer (ASMO), is capable for reducing the chattering phenomenon and decreasing the reaching time simultaneously. The stability analysis for ASMO is achieved based on Lyapunov stability theory. Simulation and experimental results both demonstrate the correctness and the effectiveness of the proposed method.

Adaptive second-order nonsingular terminal sliding mode power-level control for nuclear power plants

Jiuwu Hui,Jingqi Yuan 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.5

This paper focuses on the power-level control of nuclear power plants (NPPs) in the presence of lumpeddisturbances. An adaptive second-order nonsingular terminal sliding mode control (ASONTSMC) schemeis proposed by resorting to the second-order nonsingular terminal sliding mode. The pre-existingmathematical model of the nuclear reactor system is firstly described based on point-reactor kineticsequations with six delayed neutron groups. Then, a second-order sliding mode control approach isproposed by integrating a proportional-derivative sliding mode (PDSM) manifold with a nonsingularterminal sliding mode (NTSM) manifold. An adaptive mechanism is designed to estimate the unknownupper bound of a lumped uncertain term that is composed of lumped disturbances and system statesreal-timely. The estimated values are then added to the controller, resulting in the control system capableof compensating the adverse effects of the lumped disturbances efficiently. Since the sign function iscontained in the first time derivative of the real control law, the continuous input signal is obtained afterintegration so that the chattering effects of the conventional sliding mode control are suppressed. Therobust stability of the overall control system is demonstrated through Lyapunov stability theory. Finally,the proposed control scheme is validated through simulations and comparisons with a proportionalintegral-derivative (PID) controller, a super twisting sliding mode controller (STSMC), and a disturbance observer-based adaptive sliding mode controller (DO-ASMC)

Dynamic Integral Sliding Mode for MIMO Uncertain Nonlinear Systems

Qudrat Khan,Aamer Iqbal Bhatti,Sohail Iqbal,Mohammad Iqbal 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.1

In this paper the authors propose a novel sliding mode control methodology for Multi-Input and Multi-Output (MIMO) uncertain nonlinear systems. The proposed approach synthesizes dynamic sliding mode and integral sliding mode control strategies into dynamic integral sliding mode. The new control laws establish sliding mode without reaching phase with the use of an integral sliding manifold. Consequently, robustness against uncertainties increases from the very beginning of the process. Fur-thermore, the control laws considerably alleviate chattering along the switching manifold. In addition, the performance of the controller boost up in the presence of uncertainties. A comprehensive compara-tive analysis carried out with dynamic sliding mode control and integral sliding mode control demon-strates superiority of the newly designed control law. A chatter free regulation control of two uncertain nonlinear systems with improved performance in the presence of uncertainties ensures the robustness of the proposed dynamic integral sliding mode controller.

Fractional-Order Adaptive Sliding Mode Control for Fractional-Order Buck-Boost Converters

Xie Lingling,Liu Zhipei,Ning Kangzhi,Qin Rui 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

In previous studies, the combination of fractional calculus (FC) and sliding-mode control (SMC) has been gaining more and more interest due to fusion characteristics of SMC and FC. But most study integer-order buck converters, and few study control strategies of fractional-order converters. In this paper, the sliding mode controller and fractional adaptive sliding mode controller for fractional-order buck-boost converters are proposed. An affi ne nonlinear system model of the fractionalorder buck-boost converter is built. Based on the diff erential geometry theory, the exact feedback linearization is performed on the affi ne nonlinear model of the fractional-order buck-boost converter. On this basis, a fractional adaptive sliding mode controller is designed by selecting a linear sliding surface and adaptive control law. The stability of the fractional controller is proved by the Mittag–Leffl er stability theorem. The simulation results show that the fractional adaptive sliding mode control has good dynamic response performance and small steady-stage error regulating characteristics. Compared with traditional sliding mode control and PI λ control, the control method demonstrates stronger robustness under various disturbances.

An Adaptive Complementary Sliding-mode Control Strategy of Single-phase Voltage Source Inverters

Bo Hou,Junwei Liu,Fengbin Dong,Anle Mu 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

In order to achieve the high quality output voltage of single-phase voltage source inverters, in this paper an Adaptive Complementary Sliding Mode Control (ACSMC) is proposed. Firstly, the dynamics model of the single-phase inverter with lumped uncertainty including parameter variations and external disturbances is derived. Then, the conventional Sliding Mode Control (SMC) and Complementary Sliding Mode Control (CSMC) are introduced separately. However, when system parameters vary or external disturbance occurs, the controlling performance such as tracking error, response speed et al. always could not satisfy the requirements based on the SMC and CSMC methods. Consequently, an ACSMC is developed. The ACSMC is composed of a CSMC term, a compensating control term and a filter parameters estimator. The compensating control term is applied to compensate for the system uncertainties, the filter parameters estimator is used for on-line LC parameter estimation by the proposed adaptive law. The adaptive law is derived using the Lyapunov theorem to guarantee the closed-loop stability. In order to decrease the control system cost, an inductor current estimator is developed. Finally, the effectiveness of the proposed controller is validated through Matlab/Simulink and experiments on a prototype single-phase inverter test bed with a TMS320LF28335 DSP. The simulation and experimental results show that compared to the conventional SMC and CSMC, the proposed ACSMC control strategy achieves more excellent performance such as fast transient response, small steady-state error, and low total harmonic distortion no matter under load step change, nonlinear load with inductor parameter variation or external disturbance.

Design and Implementation of an Adaptive Sliding-Mode Observer for Sensorless Vector Controlled Induction Machine Drives

Zhang, Yanqing,Yin, Zhonggang,Liu, Jing,Tong, Xiangqian The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

An adaptive sliding-mode observer for speed estimation in sensorless vector controlled induction machine drives is proposed in this paper to balance the dilemma between the requirement of fast reaching transient and the chattering phenomenon reduction on the sliding-mode surface. It is well known that the sliding-mode observer (SMO) suffers from the chattering phenomenon. However, the reduction of the chattering phenomenon will lead to a slow transient process. In order to balance this dilemma, an adaptive exponential reaching law is introduced into SMO by optimizing the reaching way to the sliding-mode surface. The adaptive exponential reaching law is based on the options of an exponential term that adapts to the variations of the sliding-mode surface and system states. Moreover, the proposed sliding-mode observer considering adaptive exponential reaching law, which is called adaptive sliding-mode observer (ASMO), is capable for reducing the chattering phenomenon and decreasing the reaching time simultaneously. The stability analysis for ASMO is achieved based on Lyapunov stability theory. Simulation and experimental results both demonstrate the correctness and the effectiveness of the proposed method.

Design of a novel adaptive fuzzy sliding mode controller and application for vibration control of magnetorheological mount

Phu, Do Xuan,Quoc, Nguyen Vien,Park, Joon-Hee,Choi, Seung-Bok Professional Engineering Publishing Ltd 2014 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>This paper presents vibration control of a mixed-mode magnetorheological fluid-based mount system using a new robust fuzzy sliding mode controller. A novel model of controller is built based on adaptive hybrid control of interval type 2 fuzzy controller incorporating with a new modified sliding mode control. The interval type 2 fuzzy is optimized for computational cost by using enhanced iterative algorithm with stop condition, and a new modified switching surface of sliding mode control is designed for preventing the chattering of the system. The controller is then experimentally implemented under uncertain conditions in order to evaluate robust vibration control performance. In addition, in order to demonstrate the effectiveness of the proposed controller, two fuzzy sliding mode control algorithms proposed by Huang and Chan are adopted and modified. The principal control parameters of three controllers are updated online by adaptation laws to meet requirements of magnetorheological mount system which has two operation modes: flow mode and shear mode. It is shown from experimental realization of three controllers that the proposed control strategy performs the best under uncertain conditions compared with two other modified controllers. This merit is verified by presenting vibration control performances in both time and frequency domains.</P>

A Hybrid of Sliding Mode Control and Fuzzy Gain Scheduling PID Control using Fuzzy Supervisory Switched System for DC Motor Speed Control System

Husain Ahmed,Abha Rajoriya 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5

This paper shows another way to deal with speed control of DC Motor. Two nonlinear controllers, one of sliding mode control and the other Fuzzy gain scheduling PID, characterize another control structure. Essentially, in this configuration procedure, the SMC and Fuzzy gain scheduling PID controller have been consolidated by a switching system which is chosen by the Fuzzy supervisory system. The sliding-mode controller acts essentially in a transient state while the fuzzy gain scheduler PID controller acts in the steady state. The new structure epitomizes the favorable circumstances that both nonlinear controllers offer: a sliding-mode controller provides the fast rise time and fuzzy gain scheduling PID controllers lessening the chattering in the steady state. The simulation results show that utilizing the new hybrid SMC fuzzy gain scheduling PID controller gives "better" system response as far as transient and steady state are concerned when compared with the SMC or fuzzy gain scheduling PID controller’s applications. The controller parameters are tuned with the help of fuzzy logic.

Sliding Mode Control for a Class of Nonlinear Positive Markov Jumping Systems with Uncertainties in a Finite-time Interval

Chengcheng Ren,Shuping He 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

This paper studies the finite-time sliding mode control problem for a class of nonlinear positive Markovjumping systems with uncertain parameters. Firstly, a mode-dependent sliding mode surface is designed to guarantee the positiveness and finite-time boundedness of the closed-loop Markov jumping systems. Then, a suitablefinite-time sliding mode controller is given to guarantee the closed-loop MJSs can drive onto the specified slidingmode surface during a given finite-time interval and then maintain on the sliding surface. Based on the stochasticLyapunov-Krasovskii functional approach and linear matrix inequalities technique, sufficient conditions on the existence of the finite-time controller are proposed and proved. Finally, a simulation example is given to illustrate theeffectiveness of the proposed method