scholarly journals Sliding Mode Control Based on Observer for a Class of State-Delayed Switched Systems with Uncertain Perturbation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Zhaolan He ◽  
Xue Wang ◽  
Zongwei Gao ◽  
Jingjie Bai
Keyword(s):  
Sliding Mode Control ◽  
Switched Systems ◽  
Sliding Mode ◽  
Estimation Error ◽  
Matching Condition ◽  
State Observer ◽  
Sliding Surface ◽  
State Variables ◽  
Parameter Uncertainties ◽  
Mode Control

This paper is concerned with a state observer-based sliding mode control design methodology for a class of continuous-time state-delayed switched systems with unmeasurable states and nonlinear uncertainties. The advantages of the proposed scheme mainly lie in which it eliminates the need for state variables to be full accessible and parameter uncertainties to be satisfied with the matching condition. Firstly, a state observer is constructed, and a sliding surface is designed. By matrix transformation techniques, combined with Lyapunov function and sliding surface function, a sufficient condition is given to ensure asymptotic stability of the overall closed-loop systems composed of the observer dynamics and the estimation error dynamics. Then, reachability of sliding surface is investigated. At last, an illustrative numerical example is presented to prove feasibility of the proposed approaches.

Adaptive sliding mode control for stochastic switched systems with actuator faults

2018 ◽  
Vol 41 (7) ◽  
pp. 1880-1887
Author(s):  
Yonghui Liu
Keyword(s):  
Sliding Mode Control ◽  
Switched Systems ◽  
Sliding Mode ◽  
Sufficient Conditions ◽  
Adaptive Sliding Mode Control ◽  
Sliding Surface ◽  
Actuator Faults ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Actuator Degradation

The problem of adaptive sliding mode control is considered for a class of stochastic switched systems with actuator degradation. In this work, the input matrix for each subsystem is unnecessarily the same. Thus, a weighted sum approach of the input matrices is introduced such that a common sliding surface is designed. By online estimating the loss of effectiveness of the actuators, an adaptive sliding mode controller is designed. It can not only compensate the effect of the actuator degradation effectively, but also reduce the conservatism that the bound of the actuator faults should be known in advance. Moreover, it is shown that the reachability of the sliding surface can be guaranteed. Furthermore, sufficient conditions on the mean-square exponential stability of the sliding mode dynamics are obtained via the average dwell time method. Finally, a numerical simulation example is given to demonstrate the effectiveness of the proposed method.

scholarly journals Efficient Control of a Non-Linear System Using a Modified Sliding Mode Control

2019 ◽  
Vol 9 (7) ◽  
pp. 1284 ◽  
Author(s):  
Saad Abbasi ◽  
Karam Kallu ◽  
Min Lee
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Sliding Surface ◽  
Parameter Uncertainties ◽  
Pass Filter ◽  
Mode Control ◽  
Efficient Control ◽  
Non Linear ◽  
Non Linear System

Trajectory tracking is an essential requirement in robot manipulator movement and localization applications. It is a current research topic of interest, and several researchers have proposed different schemes to achieve the task accurately. This research proposes efficient control of a hydraulic non-linear robot manipulator using a modified sliding mode control, named proportional derivative sliding mode control with sliding perturbation observer (PDSMCSPO), to overcome parameter uncertainties and non-linearity. The proposed new control strategy achieves higher accuracy and better time convergence than the previous one. A positive derivative gain, which has a value less than one, is multiplied with the velocity error term of the sliding surface. The proposed control (PDSMCSPO) also achieves robustness. Results show that by introducing the derivative gain, the chattering from the system has been reduced more than classical sliding mode control (SMC). The reason is that during reaching phase this small gain multiplies with the perturbation and minimizes the effect of perturbation on the system. A smaller value of switching gain K is required as compared to SMC, and the transfer function between sliding surface and perturbation in proportional derivative sliding mode control (PDSMC)has low pass filter characteristics. The proposed PDSMCSPO has a faster response than previous sliding mode control with sliding perturbation observer (SMCSPO), and the output and sliding surface convergence to the desired value is much quicker than conventional logic. Some other characteristics such as error in the output are small because of more attenuation of the perturbation signal. Simulation and experimental results are presented for a link between the hydraulic robot manipulator and the mass damper system.

scholarly journals Novel Adaptive Sliding Mode Control with Nonlinear Disturbance Observer for SMT Assembly Machine

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Rongrong Qian ◽  
Minzhou Luo ◽  
Yao Zhao ◽  
Jianghai Zhao
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Adaptive Sliding Mode Control ◽  
Sliding Surface ◽  
Parameter Uncertainties ◽  
Nonlinear Disturbance Observer ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Nonlinear Disturbance

This paper presents a novel adaptive sliding mode control based on nonlinear sliding surface with disturbance observer (ANSMC-DOB) for precision trajectory tracking control of a surface mount technology (SMT) assembly machine. A two-degree-of-freedom model with time-varying parameter uncertainties and disturbances is built to describe the first axial mode of the pick-place actuation axis of the machine. According to the principle of variable damping ratio coefficient which makes the system have a nonovershoot transient response and a short settling time in the second-order system, the nonlinear sliding surface is designed for the sliding mode control (SMC). Since the upper bound value of the disturbances is unknown, the adaptive gain estimation is applied to replace the switching gain in the SMC. In order to settle the problem of SMC unrobust to the mismatched parameter uncertainties and disturbances, the nonlinear disturbance observer is introduced to estimate the mismatched disturbances and form the novel controller of ANSMC-DOB. The stability of sliding surfaces and control laws are verified by the Lyapunov functions. The simulation research and comparative experiments are conducted to verify the improvement of positioning accuracy and robustness by the proposed ANSMC-DOB in the SMT assembly machine.

scholarly journals Improved Nonlinear Extended State Observer-Based Sliding-Mode Rotary Control for the Rotation System of a Hydraulic Roofbolter

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 41
Author(s):  
Zhen Zhang ◽  
Yinan Guo ◽  
Xianfang Song
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Estimation Error ◽  
Dead Zone ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Mode Control ◽  
Rotation System ◽  
Nonlinear Extended State Observer

This paper develops a sliding-mode control with an improved nonlinear extended state observer (SMC-INESO) for the rotation system of a hydraulic roofbolter with dead-zones, uncertain gain, and disturbances, with the purpose of improving tracking performance. Firstly, the rotation system is modeled to compensate for dead-zone nonlinearity. Then, we present an improved nonlinear extended state observer to estimate disturbances of the rotation system in real time. Moreover, a proportional-integral-differential sliding-mode surface is introduced and an improved sliding-mode reaching law is designed. Based on this, a sliding-mode control law is developed. In order to eliminate the influence of estimation error and uncertain gain, we design two adaptation laws based on the sliding-mode surface and the estimated states. Finally, the effectiveness of the proposed SMC-INESO is verified through comparative simulation studies.

scholarly journals Neural network-based adaptive sliding mode control for underactuated dual overhead cranes suffering from matched and unmatched disturbances

2022 ◽  
Vol 2 (1) ◽  
Author(s):  
Tianci Wen ◽  
Yongchun Fang ◽  
Biao Lu
Keyword(s):  
Neural Network ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Adaptive Sliding Mode Control ◽  
Control Performance ◽  
State Variables ◽  
Parameter Uncertainties ◽  
Practical Applications ◽  
Adaptive Sliding Mode ◽  
Mode Control

AbstractTo improve transportation capacity, dual overhead crane systems (DOCSs) are playing an increasingly important role in the transportation of large/heavy cargos and containers. Unfortunately, when trying to deal with the control problem, current methods fail to fully consider such factors as external disturbances, input dead zones, parameter uncertainties, and other unmodeled dynamics that DOCSs usually suffer from. As a result, dramatic degradation is caused in the control performance, which badly hinders the practical applications of DOCSs. Motivated by this fact, this paper designs a neural network-based adaptive sliding mode control (SMC) method for DOCS to solve the aforementioned issues, which achieves satisfactory control performance for both actuated and underactuated state variables, even in the presence of matched and mismatched disturbances. The asymptotic stability of the desired equilibrium point is proved with rigorous Lyapunov-based analysis. Finally, extensive hardware experimental results are collected to verify the efficiency and robustness of the proposed method.

Sliding mode control for uncertain switched systems subject to state and input delays

2017 ◽  
Vol 40 (10) ◽  
pp. 3232-3238
Author(s):  
Yonghui Liu ◽  
Yugang Niu
Keyword(s):  
Sliding Mode Control ◽  
Control Systems ◽  
Switched Systems ◽  
Sliding Mode ◽  
Sliding Surface ◽  
Mode Control ◽  
Sliding Motion ◽  
State And Input Delays ◽  
Input Delays ◽  
Projection Strategy

This paper considers sliding mode control for a class of uncertain switched systems with state and input delays. In the control systems, each subsystem is not required to share the same input channel, which is usually assumed in previous works. By employing a weighted sum of the input matrices, a common sliding surface is designed. The sliding surface includes a predictor to compensate for the input delay of the control systems. To guarantee the asymptotic stability of the sliding motion, a switching signal based on the min-projection strategy is proposed. Moreover, it is shown that the state trajectories can be driven onto the specified sliding surface despite the presence of state and input delays and external disturbances. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.

Global Robust Sliding Mode Tracking Control for Helicopter with Input Time Delay

2013 ◽  
Vol 846-847 ◽  
pp. 434-437 ◽  
Author(s):  
Ling Cai ◽  
Fu Yang Chen ◽  
Fei Fei Lu
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sliding Surface ◽  
State Variables ◽  
Mode Control ◽  
Mode Function ◽  
Control Scheme ◽  
Input Time ◽  
Integral Sliding Surface

In this paper, a global sliding mode control scheme is proposed for a helicopter with input time delay and disturbance. We proposed a new method for integral sliding surface. By the design of dynamic nonlinear sliding mode function, the controller has the advantage of eliminating the reaching movement of traditional sliding mode control, overcoming the effect of the disturbance and time delay. The system state variables reached the sliding surface at the very beginning by means of designing a dynamic nonlinear sliding mode function, and moved to the expected state under the control of control law. The efficiency of the proposed method is demonstrated by simulation results.

scholarly journals Multi-Resonant-Based Sliding Mode Control of DFIG-Based Wind System under Unbalanced and Harmonic Network Conditions

2019 ◽  
Vol 9 (6) ◽  
pp. 1124
Author(s):  
Yu Quan ◽  
Lijun Hang ◽  
Yuanbin He ◽  
Yao Zhang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sliding Surface ◽  
State Variables ◽  
Tracking Errors ◽  
Current Harmonics ◽  
Grid Voltage ◽  
Mode Control ◽  
Torque Pulsations ◽  
Integral Sliding Surface

In general, the integral sliding mode control (ISMC) with an integral sliding surface would lead to tracking errors under unbalanced and harmonic grid voltage conditions. In order to eliminate tracking errors under these conditions, multi-resonant items are added to the conventional integral sliding surface in the proposed strategy, which can be called multi-resonant-based sliding mode control (MRSMC). A comparison of tracking precision on the ISMC and MRSMC is analyzed. In order to regulate the system powers directly, the errors of instantaneous active and reactive powers are selected as the state variables. Finally, the output current harmonics and a majority of the doubly-fed induction generator’s (DFIG) electromagnetic torque pulsations can be removed under unbalanced and harmonic grid voltage conditions. Simulation and experimental results are presented to verify the correctness and effectiveness of the proposed strategy.

scholarly journals Control of desalination plants using sliding mode scheme with state observer

2021 ◽  
Author(s):  
Bui Duc Hong Phuc ◽  
Sam-Sang You ◽  
Hwan-Seong Kim ◽  
Sang-Do Lee
Keyword(s):  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Water Productivity ◽  
State Observer ◽  
The State ◽  
State Variables ◽  
Mode Control ◽  
Product Water ◽  
Desalination Plants

Abstract This paper deals with real-time control with observer to manipulate desalination plants as well as to monitor system states for smart operations. The controller plays an important role in achieving stabilization of reverse osmosis (RO) systems to guarantee the desired water product and concentration. The super-twisting (STW) sliding mode control (SMC) algorithm guarantees performance while reducing chattering. Supposing that all the state variables are not available by sensors, the observer is implemented to provide state estimation. Since smart operations depend on control algorithm and sensor availability, the proposed strategy provides robustness to ensure the water productivity even under uncertainties or under failure of sensors. The robustness is guaranteed by active controller where 80% of disturbance is eliminated in product water flow and that of product water quality is approximately 95%. As well, the state observer can produce precise predictions of the unmeasured states. Sliding mode control with observer provides the system with stability, while assuring better performances against uncertainties. Finally, the active controller with state estimator can guarantee a robust control strategy and monitoring system to extend the life of the filters and membranes, while ensuring sustainability. This control strategy is highly recommended for smart operations of desalination plants.

Sliding mode control of uncertain dynamical systems with time delay using the continuous time approximation method

2011 ◽  
Vol 18 (9) ◽  
pp. 1254-1260 ◽  
Author(s):  
Bo Song ◽  
Jian-Qiao Sun
Keyword(s):  
Time Delay ◽  
Dynamical Systems ◽  
Sliding Mode Control ◽  
Continuous Time ◽  
Sliding Mode ◽  
Sliding Surface ◽  
State Variables ◽  
Time Approximation ◽  
Uncertain Dynamical Systems ◽  
Mode Control

A study of sliding mode control of uncertain dynamical systems with time delay is presented in this paper. The systems are assumed to have constant delay time and uncertain parameters with known upper and lower bounds. The method of continuous time approximation is applied to formulate the sliding mode control problem. The proposed treatment of the control delay leads to a higher-order control formulation for a system with additive uncertainties only. An optimal sliding surface is designed such that on the sliding surface, the controlled state variables act like a feedback control to the uncontrolled state variables. Examples of non-linear systems are presented to demonstrate the theoretical work.

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