최적 절환 초평면을 갖는 슬라이딩 모드에 의한 DC모터의 강인한 속도제어

—Stability, robust and reliability are the main objectives to design a controller for highly nonlinear spherical motor. Most of linear and nonlinear controllers are stable, model-base controllers are reliable but in this group sliding mode controller is a robust controller. Therefore in this research sliding mode controller is used to design stable, robust and reliable controller. For intelligence part, the minimum rule base Proportional Integral Derivative (PID) Fuzzy hybrid guidance Controller for three dimensions spherical motor is presented in this research. Guidance control in a three dimensions spherical motor is performed by the robust sliding mode controllers producing the control signals which are applied to systems torque. Sliding mode controller has an important problem, namely chattering. In this research, chattering-free sliding mode controller is design as a robust guidance controller to their robust performance in a wide range of operating conditions. In this research the PID-like fuzzy controller can be constructed as a parallel structure of a PD-like fuzzy controller and a PI-like controller to have the minimum rule base. Nonlinear type robust sliding mode controller is used to modify PID fuzzy logic theory to design robust and reliable hybrid guidance methodology. This research is used to reduce or eliminate the fuzzy and conventional sliding mode controller problem based on minimum rule base fuzzy logic theory and modified it by sliding mode method to control of spherical motor system.

To improve the performance of vehicle-grid system under multiple operation conditions and suppress the low-frequency oscillation (LFO) in electrified railways, this paper proposed a control strategy of electric multiple units (EMUs) traction line-side converter (LSC) based on sliding mode control (SMC). First, the accurate model of EMUs is established and then the mathematical model of it in the d-q frame is derived. Then, the application of sliding mode variable structure control strategy in the LSC of EMUs is presented in detail, which includes the design of outer loop voltage sliding mode surface and inner loop current control law. Moreover, the control performance for EMUs based on SMC and traditional linear proportional integral (PI) control is compared under multiple operation conditions in the case of one traction drive unit of EMUs and multi-EMUs, respectively. Finally, experiments are implemented on the hardware in the loop simulation platform based on software StarSim. The experiments results show that, compared with PI control, SMC owns better control performance, such as the lower total harmonic distortion of traction line-side current under multiple conditions, lower voltage fluctuation when braking occurs, better anti-interference ability with the change of system parameters, and can effectively suppress the LFO occurs under operation mode.

The interval type-2 fuzzy Proportional-Integral (PI) controller (IT2-FPI) might be able to handle high levels of uncertainties to produce a satisfactory control performance, which could be potentially due to the robust performance as a result of the smoother control surface around the steady state. However, the transient state and disturbance rejection performance of the IT2-FPI may degrade in comparison with the type-1 fuzzy PI (T1-FPI) counterpart. This drawback can be resolved via general type-2 fuzzy PI controllers which can provide a tradeoff between the robust control performance of the IT2-FPI and the acceptable transient and disturbance rejection performance of the type-1 PI controllers. In this paper, we will present a zSlices-based general type-2 fuzzy PI controller (zT2-FPI), where the secondary membership functions (SMFs) of the antecedent general type-2 fuzzy sets are adjusted in an online manner. We will examine the effect of the SMF on the closed-system control performance to investigate their induced performance improvements. This paper will focus on the case followed in conventional or self-tuning fuzzy controller design strategies, where the aim is to decrease the integral action sufficiently around the steady state to have robust system performance against noises and parameter variations. The zSlices approach will give the opportunity to construct the zT2-FPI controller as a collection of IT2-FPI and T1-FPI controllers. We will present a new way to design a zT2-FPI controller based on a single tuning parameter where the features of T1-FPI (speed) and IT2-FPI (robustness) are combined without increasing the computational complexity much when compared with the IT2-FPI structure. This will allow the proposed zT2-FPI controller to achieve the desired transient state response and provide an efficient disturbance rejection and robust control performance. We will present several simulation studies on benchmark systems, in addition to real-world experiments that were performed using the PIONEER 3-DX mobile robot that will act as a platform to evaluate the proposed systems. The results will show that the control performance of the self-tuning zT2-FPI control structure enhances both the transient state and disturbance rejection performances when compared with the type-1 and IT2-FPI counterparts. In addition, the self-tuning zT2-FPI is more robust to disturbances, noise, and uncertainties when compared with the type-1 and interval type-2 fuzzy counterparts.

Robust control of an industrial boiler system; a comparison between two approaches: Sliding mode control & [formula omitted] technique

In this work, the genetic algorithm (GA) and input estimation approach (IE) are proposed to design a sliding mode controller (SMC) that hold ability of disturbance torque estimation and the robust control performance. The IE approach is an on-line recursive inverse estimation method based on the Kalman filter (KF) and recursive least square estimator method (RLSE), which estimates the disturbance torque without additional torque sensor. The sliding mode control theory has the characteristics of low sensitivity with variable system parameters. Furthermore, the genetic algorithm is proposed to search the optimal controller design parameters for SMC that it can promote the control performance.

The main objective of this paper is to control the speed of separately excited DC Motor using a Sliding mode controller based on VSS approach. This controller is based on variable structure systems which aim at reducing the peak overshoot, steady state error and settling time of a DC Motor. In the first stage, PI controller is used to control the speed of DC Motor. A model is developed and simulated using MATLAB/SIMULINK. Later on the same is done with sliding mode controller. The speed control of DC Motor using both PI and Sliding mode controllers is studied and the results are compared. The simulation results show that Sliding mode controller is superior than PI for speed control of DC motor. Since the SMC is robust in presence of disturbances, the desired speed is perfectly tracked.

Power systems are nonlinear multidimensional and multichannel complex objects. There are some structure and parameter uncertainties in power systems. For uncertainties compensation are used robust and adaptive control methods. The sliding mode control theory is one type of the robust control theories, which can obtain low sensitivity to object parameters changes. Therefore, new approach of nonlinear sliding mode control theory is shown in this paper. It's called synergetic sliding mode control. Here is described the procedure of synergetic sliding mode control for nonlinearly controlled objects. Proposed procedure is based on aggregated regulators analytical design (ARAD) method - the basic method of synergetic control theory. Application of this theory has been reviewed for synthesis of synchronous generator (SG) excitation nonlinear robust control law. Robustness and control performance of the proposed method are examined by numerical simulations.

Currently, the main control strategy of the modular multi‐level converter (MMC) is a combination of vector control (VC) and proportional‐integral (PI) control, which allows decoupling active and reactive power control and maintaining the power balance within the high voltage direct current (HVDC) system. Although the existing PI control or conventional sliding mode control (SMC) shows a satisfactory control performance under steady state, its robust performance is poor when parameter uncertainty occurs, which greatly affects the stable operation of MMC. Therefore, a novel interval sliding mode control (ISMC) for MMC‐based HVDC systems is proposed in this paper, along with the stability criterion and design procedure. The proposed method can attenuate the influence of the parameter uncertainty, make the system robust and stable, and achieve both satisfactory transient and steady‐state performance under parameter uncertainty. The comparative simulation experiments of PI control, conventional SMC, and ISMC for MMC were conducted in PSCAD/EMTDC, demonstrating that the proposed ISMC shows better robustness and tracking performance than either PI control or SMC under different disturbance working conditions.

The rising demand for high-performance permanent magnet synchronous motors (PMSMs) is responsible for the development of PMSM speed control. Although the proportional-integral controller is often used in field-oriented control (FOC) for motor speed regulation, it has drawbacks like slow response and instability. This paper proposed an enhanced sliding mode controller with a modified sliding surface to achieve better speed control performance. In comparison to proportional-integral or PI controller, fuzzy logic controller, conventional sliding mode controller, the proposed control approach uses a reaching law that incorporates a fuzzy logic controller. A smoother and faster response time is targeted by the proposed approach compared to conventional sliding mode control. Practical small-scale PMSM experiments certify the effectiveness of our proposed enhanced sliding mode control.

In this paper, a robust speed controller for an induction motor is proposed. The speed controller consists of a fuzzy sliding adaptive controller (FSAC) and a sliding mode torque observer (SMTO). The FSAC removes the problem of oscillations caused by discontinuous inputs of the sliding mode controller. The controller also provides robust characteristics against parameter and sampling time variations. Although, however, the performance of FSAC is better than the PI controller and fuzzy controller in robustness, it generates the problem of slow response time. To alleviate this problem, a compensator, which performs feedforward control using torque signals produced by the SMTO, is added. The simulation and hardware implementation results show that the proposed system is robust to the load disturbance, parameter variations, and measurement noises.

Sliding Mode – PI controller is recognized as robust controller with a high stability in a wide range of operating conditions, although it suffers from chattering problem. In addition, it cannot be directly applied to multi switches power converters. This paper concerns a sliding controller design with the proportional-integral (PI) control form. First, a theoretical analysis of the considered sliding PI controller is provided. Our analysis reveals that the proportional control term of the sliding PI controller, i.e., sliding proportional controller, can reduce the chattering problem and thus, the robustness can be established. Second, the chattering problem is eliminated by smoothing the control law in a narrow boundary layer, and a pulse width modulator produces the fixed frequency switching law for the inverter. The smoothing procedure is based on limitation of pulse width modulator. Therefore, the chattering problem of the proportional gain is resolved and the valuable robust control property of the sliding integral controller is illustrated again. The simulation model has been developed and tested using MATLAB software.

An effective method, adaptive fuzzy sliding-mode (SM) PI Control to design full-bridge inverter is proposed in this paper. For practical applications, sliding mode control (SMC) with chattering phenomenon is a large hindrance. The modified model of the PI controller is built by the plant extension scheme, in order to relieve the chattering. Also, the fuzzy logic is applied to find the appropriate parameter values of the PI controller, and can adapt to plant parameter variations and external load disturbances. The proposed method has been realized for the actual full-bridge inverters controlled by DSP and CPLD. Simulation and experimental results of the closed-loop system show that the proposed method yields system performance improvement, such as low total harmonic distortion (THD), fast dynamic response, reduced steady-state error, and reduced chattering.

Robust internal model control of servo motor based on sliding mode control approach

Multiport DC-DC converters have been most commonly used in stand-alone renewable power systems to provide smooth and constant power to the loads. To supply the load without any interruption under various disturbances, the centralised controller in various typologies of multiport converter has been implemented only by using conventional proportional integral (PI) controller. This study presents the output voltage control of the three-port full-bridge converter interfacing photovoltaic (PV) system with three different controllers. The dynamic response of the proposed converter is analysed with the PI controller, fuzzy logic controller (FLC), and the sliding mode controller (SMC). The state space model of the three-port full-bridge converter is developed to analyse the performance using SMC. PI, FLC, and SMC-based control scheme is developed using the MATLAB/Simulink environment. The response of the PI, FLC, and SMC are analysed for line regulation, load voltage regulation, and for the converter parameter variation. The simulation results illustrate that the SMC gives a better steady state and dynamic response when compared with the PI and FLC. The results are presented to confirm the proposed control schemes.

This paper has aimed to design fractional-order sliding mode controller (FO-SM) for time delayed MIMO system. The proposed controller has many uncertain parameters so we used adaptive particle swarm optimization method to determine the parameters. The controller provides faster tracking and more stable structure than the integer order. The selection of the controller parameters is important for control performance so intelligent optimization can provide optimal control parameters. Simulation results show that FO-SM controller has robust control performance through change of time delay.