scholarly journals Design and experiment of adaptive modified super-twisting control with a nonlinear sliding surface for a quadrotor helicopter

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880493 ◽  
Author(s):  
Reesa Akbar ◽  
Naoki Uchiyama
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Sliding Mode Control ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Time Varying ◽  
Sliding Surface ◽  
Quadrotor Helicopter ◽  
Twisting Control ◽  
Super Twisting Control

Quadrotor unmanned aerial vehicle is a nonlinear system of 6-degree-of-freedom motion. In order to handle the nonlinearity that causes undesirable behavior, robustness of flight control has been studied. In this work, we consider the combination of higher order sliding mode control and nonlinear time-varying sliding surface for robustness and accuracy in tracking. An adaptive super-twisting control, a second-order sliding mode control, is utilized to compensate for the uncertainty and perturbation of a quadrotor system. A time-varying sliding surface is designed with a nonlinear function to provide varying properties of closed-loop dynamics and to improve control performance with energy consumption reduction. The proposed control system performance including energy consumption was compared among nonlinear adaptive super-twisting control algorithm, linear adaptive super-twisting control algorithm, and linear super twisting controllers, without and under wind disturbance. The robustness and effectiveness of the proposed control system are demonstrated by several times simulation and experiment using a quadrotor helicopter test bed.

scholarly journals New Time-Varying Sliding Surface for Switching Type Quasi-Sliding Mode Control

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3811
Author(s):  
Katarzyna Adamiak ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode Control ◽  
Continuous Time ◽  
Sliding Mode ◽  
Representative Point ◽  
Time Varying ◽  
Sliding Surface ◽  
External Disturbances ◽  
Mode Control ◽  
Switching Type ◽  
Time Systems

This study considers the problem of energetical efficiency in switching type sliding mode control of discrete-time systems. The aim of this work is to reduce the quasi-sliding mode band-width and, as follows, the necessary control input, through an application of a new type of time-varying sliding hyperplane in quasi-sliding mode control of sampled time systems. Although time-varying sliding hyperplanes are well known to provide insensitivity to matched external disturbances and uncertainties of the model in the whole range of motion for continuous-time systems, their application in the discrete-time case has never been studied in detail. Therefore, this paper proposes a sliding surface, which crosses the system’s representative point at the initial step and then shifts in the state space according to the pre-generated demand profile of the sliding variable. Next, a controller for a real perturbed plant is designed so that it drives the system’s representative point to its reference position on the sliding plane in each step. Therefore, the impact of external disturbances on the system’s trajectory is minimized, which leads to a reduction of the necessary control effort. Moreover, thanks to a new reaching law applied in the reference profile generator, the sliding surface shift in each step is strictly limited and a switching type of motion occurs. Finally, under the assumption of boundedness and smoothness of continuous-time disturbance, a compensation scheme is added. It is proved that this control strategy reduces the quasi-sliding mode band-width from O(T) to O(T3) order from the very beginning of the regulation process. Moreover, it is shown that the maximum state variable errors become of O(T3) order as well. These achievements directly reduce the energy consumption in the closed-loop system, which is nowadays one of the crucial factors in control engineering.

scholarly journals Super-twisting Control of Magnetic Levitation System

2020 ◽  
Vol 32 ◽  
pp. 01004
Author(s):  
Rupak Rokade ◽  
Deepti Khimani
Keyword(s):  
Sliding Mode Control ◽  
Magnetic Levitation ◽  
Sliding Mode ◽  
Second Order ◽  
Mode Control ◽  
Levitation System ◽  
Magnetic Levitation System ◽  
Twisting Control ◽  
Super Twisting Control ◽  
Second Order Sliding Mode

This article presents the implementation results of second order sliding mode control (SOSM) for magnetic levitation system. In practical systems, especially when the actuators are electro-mechanical, the conventional (first order) sliding mode control can not be used effectively as it exhibits chattering, which is highly undesirable. Therefore, for such systems, sliding mode control of higher order can be a suitable choice as the reduce the chattering significantly. In this article the super-twisting control, which isa second order sliding mode control, is designed and implemented for the experimental setup of Maglev system, Model 730 developed by ECP systems.

scholarly journals Robustness control for nonlinear systems based on homogeneous prescribed sliding mode control

2021 ◽  
Vol 4 (2) ◽  
pp. 1019-1035
Author(s):  
PHU XUAN DO ◽  
HUNG QUOC NGUYEN
Keyword(s):  
Energy Consumption ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Control Function ◽  
Linear Matrix ◽  
Sliding Surface ◽  
Seat Suspension ◽  
Mode Control ◽  
Input Control ◽  
Severe Disturbance

This paper presents a new homogeneous control using dual sliding mode control, and robustness control using linear matrix inequality (LMI) constraints. The controller is applied for the severe disturbance. A sliding surface function, which relates to an exponential function and itself t-norm, is applied to save the energy consumption of the control system. The constraints related LMI are proposed with the matrices and vectors of the systems following the chosen matrices in control the energy for control. Solution of the constraints is also presented with new approach to save the time of calculation. In addition, the proof for the proposed controller is also presented by using the candidate Lyapunov function. In the input control function, the t-norm type is embedded to improve its performance in control disturbance. Besides of the t-norm, the modified sliding surface in the input control is also improve the energy for controlling. The combination of these robustness control elements would bring a new view for the design of control. The advantages of the controller are demonstrated via computer simulation for a seat suspension system. A magneto-rheological fluid seat suspension with its random disturbances is used. To prove the flexibility of the controller, the proposed approach is compared with an existing controller. The compared control has the same structure as shown in the proposed model. However, its design has a disadvantage in control the severe disturbance. The comparison between two controls is a clear view of distinct improvement. The results of simulations show that the controller provides better performance and stability of the system. The stability is also analyzed through the variation of the input control and power spectral density related energy consumption.

Fractional-Order Variable-Gain Super-Twisting Control With Application to Wafer Stages of Photolithography Systems

2020 ◽  
Author(s):  
Zhian Kuang ◽  
Liting Sun ◽  
Huijun Gao ◽  
Masayoshi Tomizuka
Keyword(s):  
Fractional Order ◽  
Sliding Mode ◽  
Response Speed ◽  
Tracking Performance ◽  
Sliding Surface ◽  
Variable Gain ◽  
Equivalent Control ◽  
Order Variable ◽  
Twisting Control ◽  
Super Twisting Control

Abstract In this paper, a novel fractional-order variable-gain super-twisting control (FVSTC) scheme is proposed and applied to improve the tracking performance of wafer stages in the photolithography systems. The FVSTC overcomes the drawbacks of the super-twisting control (STC) such as slow response speed and incomplete compensation to disturbances. First, to improve the dynamics of the states on the sliding surface, a fractional-order sliding surface is designed. Moreover, to improve the dynamics of the sliding mode variable, an equivalent-control-based method is utilized, and a switching controller based on a variable-gain super-twisting algorithm is deployed. Via such designed schemes, the proposed controller is robust against external disturbances and model uncertainties. Stability proof of the closed-loop system is provided. Numerical simulations to track a sinusoidal signal and experiments on a wafer stage testbed are conducted. The results show that the proposed FVSTC scheme can achieve much better tracking performance than conventional methods.

Finite-time H∞ sliding mode control of uncertain T-S fuzzy system with time-varying delay based on observer

2021 ◽  
Vol 40 (1) ◽  
pp. 983-999
Author(s):  
Huan Li ◽  
Pengyi Tang ◽  
Yuechao Ma
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Time Interval ◽  
Sliding Mode Controller ◽  
Time Varying ◽  
Sliding Surface ◽  
State Estimator ◽  
Mode Control

In this paper, a class of observer-based sliding mode controller is designed, and the finite-time H∞ control problem of uncertain T-S fuzzy systems with time-varying is studied. Firstly, an integral-type sliding surface function with time-delay is devised based on the state estimator, and sufficient criteria of finite-time bounded and finite-time H∞ bounded can be obtained for the T-S systems. Moreover, the proposed sliding mode control law is integrated to ensure the dynamics of controlled system into the sliding surface in a finite-time interval. Then, according to the linear matrix inequalities (LMIs), the desired gain matrices of fuzzy sliding mode controller and state estimator are derived. Finally, effectiveness gives some illustrative examples may be used to display the value of the current proposed method as well as a significant improvement.

PMLSM Nonlinear Integral Sliding Mode Control Based on Gain Time- Varying Reaching Law

2020 ◽  
Vol 13 (5) ◽  
pp. 743-750
Author(s):  
Chao Zhang ◽  
Liwei Zhang ◽  
Bo Peng ◽  
He Zhao
Keyword(s):  
Sliding Mode Control ◽  
Permanent Magnet ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Linear Motor ◽  
Time Varying ◽  
Sliding Surface ◽  
Reaching Law ◽  
Mode Control ◽  
Global Robustness

Background: The permanent magnet synchronous linear motor is a strongly coupled, nonlinear system. It has been applied in many fields, especially in the field of machining lathes and rail transportation. In order to ensure the permanent magnet synchronous linear motor has good dynamic performance and robustness, sliding mode control is gradually applied to the control system of permanent magnet synchronous linear motor. However, in the traditional sliding mode control, the convergence speed is slow, and the robust performance is poor when the sliding surface is not reached. Objective: The main purpose of this paper is to improve the dynamic performance and robustness of the permanent magnet synchronous linear motor during the process of approaching the sliding surface. Methods: Firstly, the type of nonlinear curve with "small error reduction, large error saturation" is introduced to design a nonlinear integral speed controller with global robustness. Secondly, the gain rate time-varying reaching law is introduced to reduce "chattering". Finally, using a symbolic tangent function instead of a sign function in designing a sliding mode observer reduces fluctuations in load observations. Results: Finally, the correctness and effectiveness of the control method are proved by simulation. Conclusion: The results of the simulation show that the nonlinear integral sliding mode controller based on gain time-varying reaching law is shown to have good global robustness and dynamic performance.

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