scholarly journals Sliding Mode Control Based on Disturbance Observer for Greenhouse Climate Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Lijun Chen ◽  
Shangfeng Du ◽  
Dan Xu ◽  
Yaofeng He ◽  
Meihui Liang
Keyword(s):  
Sliding Mode Control ◽  
Feedback Linearization ◽  
Disturbance Observer ◽  
Control Method ◽  
Sliding Mode ◽  
Control Technique ◽  
Integral Sliding Mode ◽  
Greenhouse Climate ◽  
Mode Control ◽  
Temperature And Humidity

Greenhouses are closed environments that require careful climatic control, which can benefit from a system control method to cope with the high nonlinearity, complex coupling, and robustness of unknown disturbances. This paper presents a general framework for an integral sliding mode controller based on a disturbance observer combined with feedback linearization for a greenhouse temperature and humidity system. The first-principle greenhouse climate model is described as a standard affine nonlinear system. The feedback linearization control law is used to achieve a system consisting of two separate integrator channels for temperature and humidity. System compound disturbances are estimated by applying a sliding mode disturbance observer. Based on the observer, an integral sliding mode control is incorporated to enhance the robustness against uncertainties and guarantee satisfactory tracking performance even when there are unknown estimation errors. The validity and efficacy of the proposed control technique for greenhouse climate tracking were verified by comparison with simulation results obtained using the common sliding mode control method using feedback linearization without the disturbance observer. Based on this comparison, the developed controller shows a faster system response speed, higher control precision, and stronger anti-interference ability. This method can be applied to improve greenhouse climate control systems.

Tracking control of an underwater manipulator using fractional integral sliding mode and disturbance observer

2020 ◽  
pp. 1-12
Author(s):  
Lijun Han ◽  
Guoyuan Tang ◽  
Ruikun Xu ◽  
Hui Huang ◽  
De Xie
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Fractional Integral ◽  
Controller Design ◽  
Sliding Mode ◽  
Parameter Uncertainties ◽  
Integral Sliding Mode ◽  
Finite Time Stability ◽  
Mode Control ◽  
Underwater Manipulator

In this paper, a fractional integral sliding mode control (FISMC) strategy with a disturbance observer (DO) is proposed for the trajectory tracking problem of the underwater manipulator, under lumped disturbances namely parameter uncertainties and external disturbances. The modified fractional integral sliding mode surface (FISMS) is designed to guarantee the fast convergence of system states. The DO method and the second-order sliding mode control law are used in the controller design, in which the former is introduced to compensate the effect of the lumped disturbances. Also, a saturated function is selected to replace the sign function to attenuate the chattering phenomenon. The stability of the overall closed-loop system is proved via Lyapunov’s finite-time stability theory. Numerical simulations are performed on a 6 degree of freedom (DOF) underwater manipulator. Simulation results demonstrate that the proposed control scheme can achieve better tracking performance and stronger robustness against disturbances, by comparing with the DO-based PD control and the DO-based PID-type linear sliding mode control (SMC).

Global sliding mode control for the underactuated translational oscillator with rotational actuator system

2020 ◽  
pp. 095965182094613
Author(s):  
Xianqing Wu ◽  
Kexin Xu
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Sliding Mode ◽  
Nonlinear Disturbance Observer ◽  
Mode Control ◽  
Global Sliding Mode Control ◽  
Actuator System ◽  
Nonlinear Disturbance ◽  
Rotational Actuator

This article is motivated by the control issues of the translational oscillator with rotational actuator system in the existence of uncertain disturbances. A nonlinear disturbance observer and a global sliding mode control method are proposed for the disturbance estimation and stabilization of the translational oscillator with rotational actuator system. Compared with the existing control methods, uncertain disturbances are estimated by the proposed nonlinear disturbance observer. In addition, the sliding mode control method is continuous and global robustness with respect to disturbances. Specifically, to facilitate the controller design, the dynamics of the translational oscillator with rotational actuator system are rearranged as the cascade form first. Then, a virtual signal is constructed and corresponding error dynamics are derived. Subsequently, a nonlinear disturbance observer and a continuous global sliding mode control method are proposed for the disturbance rejection and stabilization of the translational oscillator with rotational actuator system. Finally, simulation results are provided to verify the effectiveness and robustness of the proposed controller.

scholarly journals Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Guoliang Zhao ◽  
Kaibiao Sun ◽  
Hongxing Li
Keyword(s):  
Sliding Mode Control ◽  
Tensor Product ◽  
Model Transformation ◽  
Control Method ◽  
Sliding Mode ◽  
Product Model ◽  
Integral Sliding Mode Control ◽  
Integral Sliding Mode ◽  
Mode Control ◽  
Equivalent Control

This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.

scholarly journals Smooth Sliding Mode Control for Vehicle Rollover Prevention Using Active Antiroll Suspension

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Duanfeng Chu ◽  
Xiao-Yun Lu ◽  
Chaozhong Wu ◽  
Zhaozheng Hu ◽  
Ming Zhong
Keyword(s):  
Sliding Mode Control ◽  
Load Transfer ◽  
Control Method ◽  
Sliding Mode ◽  
Dynamics Simulation ◽  
Control Technique ◽  
Simulating Experiment ◽  
Mode Control ◽  
Rollover Prevention ◽  
Robust Stability Analysis

The rollover accidents induced by severe maneuvers are very dangerous and mostly happen to vehicles with elevated center of gravity, such as heavy-duty trucks and pickup trucks. Unfortunately, it is hard for drivers of those vehicles to predict and prevent the trend of the maneuver-induced (untripped) rollover ahead of time. In this study, a lateral load transfer ratio which reflects the load distribution of left and right tires is used to indicate the rollover criticality. An antiroll controller is designed with smooth sliding mode control technique for vehicles, in which an active antiroll suspension is installed. A simplified second order roll dynamic model with additive sector bounded uncertainties is used for control design, followed by robust stability analysis. Combined with the vehicle dynamics simulation package TruckSim, MATLAB/Simulink is used for simulating experiment. The results show that the applied controller can improve the roll stability under some typical steering maneuvers, such as Fishhook and J-turn. This direct antiroll control method could be more effective for untripped rollover prevention when driver deceleration or steering is too late. It could also be extended to handle tripped rollovers.

scholarly journals Control of Chaos in Rate-Dependent Friction-Induced Vibration Using Adaptive Sliding Mode Control and Impulse Damper

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Ehsan Maani Miandoab ◽  
Aghil Yousefi-Koma ◽  
Saeed Hashemnia
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Control Technique ◽  
Adaptive Sliding Mode Control ◽  
Control Law ◽  
Adaptive Sliding Mode ◽  
Chaotic Vibration ◽  
Mode Control ◽  
Rate Dependent

Two different control methods, namely, adaptive sliding mode control and impulse damper, are used to control the chaotic vibration of a block on a belt system due to the rate-dependent friction. In the first method, using the sliding mode control technique and based on the Lyapunov stability theory, a sliding surface is determined, and an adaptive control law is established which stabilizes the chaotic response of the system. In the second control method, the vibration of this system is controlled by an impulse damper. In this method, an impulsive force is applied to the system by expanding and contracting the PZT stack according to efficient control law. Numerical simulations demonstrate the effectiveness of both methods in controlling the chaotic vibration of the system. It is shown that the settling time of the controlled system using impulse damper is less than that one controlled by adaptive sliding mode control; however, it needs more control effort.

A novel second-order sliding mode control based on the Lyapunov method

2018 ◽  
Vol 41 (4) ◽  
pp. 1068-1078 ◽  
Author(s):  
Lu Liu ◽  
Shihong Ding ◽  
Li Ma ◽  
Haibin Sun
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Disturbance Observer ◽  
Control Method ◽  
Sliding Mode ◽  
Second Order ◽  
Lyapunov Theory ◽  
Mode Control ◽  
Mismatched Disturbance ◽  
Second Order Sliding Mode

In this paper, a novel discontinuous second-order sliding mode control approach has been developed to handle sliding mode dynamics with a nonvanishing mismatched disturbance by using Lyapunov theory and a finite-time disturbance observer. Firstly, the finite-time disturbance observer is designed to estimate the nonvanishing mismatched disturbance. Secondly, a virtual controller has been constructed based on the estimated value such that the sliding variable can be stabilized to zero in a finite time. Then, the real discontinuous controller is designed to guarantee that the virtual controller can be well tracked in a finite time. Lyapunov analysis also verifies the finite-time stability of the closed-loop sliding mode control system. The developed discontinuous second-order sliding mode control method possesses two appealing features including strong robustness with respect to the matched and mismatched nonvanishing disturbances, and relaxation on the constant upper bound of uncertainties widely used in a conventional second-order sliding mode. Finally, an academic example is illustrated to verify the effectiveness of the proposed method.

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