A new adaptive fractional sliding mode control of a MEMS gyroscope

Microsystem Technologies - The Micro-Electro-Mechanical System (MEMS) gyroscope is a well-known device, which has been widely used in medicine due to its small size. In this study, a new adaptive...     

A novel adaptive high-order sliding mode control based on integral sliding mode

This paper presents an adaptive high-order sliding mode control scheme targeting for uncertain minimum phase nonlinear single-input-single-output (SISO) systems, which can be equivalently formulated as the finite-time stabilization of high-order input-output dynamics subject to the uncertainties of parameters such as a chain of integrators. The proposed controller is derived from the concept of integral sliding mode and consists of two parts, one part of which achieves the finite-time stabilization of the high-order input-output dynamics without uncertainties by solving a finite-horizon optimal control problem with a free-final-state. The other part adopts the adaptive sliding mode control technique considering the practical bounded uncertainties, by which a modified switching gain adaptation algorithm is developed so that the on-line switching gain selection can be executed and the upper bounds of the uncertainties are not requisite in advance. As a result, a high-order sliding mode is established, ensuring the sliding variables and its high-order derivatives converge to an arbitrarily small vicinity of the origin in finite time. Therefore, the proposed controller achieves fixed convergence time and further improves strong robustness against bounded uncertainties with lower chattering and the easy implementation. Simulation results are presented in detail to verify the effectiveness and feasibility of the proposed algorithm.     

Robust adaptive neural sliding mode control of MEMS triaxial gyroscope with angular velocity estimation

In this paper, a robust adaptive sliding mode control strategy of micro electro-mechanical system (MEMS) triaxial gyroscope using radial basis function (RBF) neural network is presented for the system identification of MEMS gyroscope. A key property of this scheme is that the prior knowledge of the upper bound of the system uncertainties is not required. An adaptive RBF neural network controller is used to learn the unknown upper bound of model uncertainties and external disturbances. The adaptive RBF neural network is incorporated into the adaptive sliding mode control in the Lyapunov sense, and the stability of the proposed adaptive neural sliding mode control can be established. The dynamics and angular velocities of gyroscope can be identified in real time. Numerical simulations are investigated to verify the effectiveness of the proposed adaptive neural sliding mode control scheme, showing that the designed control system has better robust performance in its insensitivity to system nonlinearities; moreover, system parameters including angular velocity can be consistently estimated and tracking errors converge to zero asymptotically.     

一类非线性不确定系统的自适应积分滑模控制

针对一类具有不确定参数的复杂非线性系统,提出了一种自适应积分滑模控制方法。控制器的设计分两步进行：首先,基于被控对象模型构造一个简化子系统,设计出该子系统的一个全局渐近稳定控制律;然后构造一个积分滑模面,设计自适应积分滑模补偿器以处理系统中含有不确定参数的部分,保证了滑模面的可达性和原系统的闭环稳定性。补偿后,系统的完整自适应控制律由简化子系统的控制律加补偿控制器两部分组成。所提设计方法简单,便于工程实现。最后,通过仿真结果验证了设计方案的有效性。     

A novel continuous fractional sliding mode control

A new fractional-order controller is proposed, whose novelty is twofold: (i) it withstands a class of continuous but not necessarily differentiable disturbances as well as uncertainties and unmodelled dynamics, and (ii) based on a principle of dynamic memory resetting of the differintegral operator, it is enforced an invariant sliding mode in finite time. Both (i) and (ii) account for exponential convergence of tracking errors, where such principle is instrumental to demonstrate the closed-loop stability, robustness and a sustained sliding motion, as well as that high frequencies are filtered out from the control signal. The proposed methodology is illustrated with a representative simulation study.     

Optimal novel super-twisting PID sliding mode control of a MEMS gyroscope based on multi-objective bat algorithm

Microsystem Technologies - This paper proposes a novel super-twisting PID sliding mode controller (STPIDSMC) using a multi-objective optimization bat algorithm (MOBA-STPIDSMC) for the control of a...     

一种无模型自适应积分终端滑模控制方法

针对一类包含扰动的非线性离散时间系统,提出一种新的无模型自适应离散积分终端滑模控制算法.该算法基于紧格式动态线性化数据模型,利用离散积分终端滑模控制算法设计无模型自适应控制器,并采用扰动估计技术估计系统的扰动项,其中动态线性化方法中“伪偏导数”的估计算法仅依赖于被控系统的I/O测量数据.理论分析证明了系统输入输出有界,并通过仿真实验验证了所提算法的有效性.     

陀螺仪系统同步控制的参数自适应滑模控制

针对带有内部不确定性及外部扰动的陀螺仪混沌系统的同步问题,提出了一种参数自适应滑模控制方法,并给出参数自适应律.该方法不依赖被控混沌系统的数学模型,可以快速跟踪主混沌系统.时域及复频域理论分析表明,由参数自适应滑模控制器组成的闭环控制系统是全局渐近稳定的,而且参数自适应滑模控制器具有良好的抗扰动鲁棒性.仿真结果表明该控制方法计算量小、响应速度快、控制精度高、抗扰动鲁棒性强,在非线性不确定系统控制领域具有广泛的应用价值.     

A novel fixed-time fractional order nonsingular terminal sliding mode control

In order to reduce the convergence time of permanent magnet linear synchronous motor (PMLSM) and improve the robustness of system, a fixed-time fractional order nonsingular terminal sliding mode control (FTFONTSMC) strategy is designed to realize the rapidity and accuracy of PMLSM position tracking response. Firstly, an improved fixed-time terminal sliding mode (FTTSM) reaching law is proposed to reduce the time of convergence. Secondly, due to the uncertainty of the disturbance in PMLSM system, an exponential convergent disturbance observer (DO) is designed to observe the disturbance. Further, finite time stability of the control system is proved by Lyapunov stability theory. Finally, the above control algorithm is applied to PMLSM, and the proposed control method's effectiveness and superiority are validated by comparing with existing control methods.     

自适应模糊全局快速Terminal滑模控制方法

提出了一种自适应模糊全局快速Terminal滑模控制方法,在参数不确定性和外干扰情况下,为解决系统的非线性不确定性提供了一种新途径。与传统模糊Terminal滑模控制相比,通过采用模糊逻辑系统来逼近未知系统函数和开关项;鲁棒自适应律用来减小逼近误差,从而有效降低抖振;证明了该控制方案的稳定性,并将该方案应用在倒立摆系统中。仿真结果验证了该方案的有效性。     

Chattering-free sliding mode control-based disturbance observer for MEMS gyroscope system

Microsystem Technologies - This paper proposes a novel disturbance observer (DOB) based on the free-chattering sliding-mode control (SMC) to compensate the changing of the disturbance and uncertain...     

一类非线性大滞后系统自适应积分滑模控制

针对一类非线性大滞后系统, 基于伪偏导数概念的动态线性化非线性系统模型, 利用离散时间预测器技术, 实现了系统原始表达式中滞后环节的隐性表达, 并结合离散积分滑模控制(discrete integral sliding mode control, DISMC)方法, 提出了一种新的无模型自适应离散积分滑模控制(model-free adaptive discrete integral sliding mode control, MFA-DISMC)方案. 该方法的主要特点是控制器设计仅取决于被控对象的输入和输出测量数据. 通过理论分析证明了算法的稳定性, 仿真研究表明, 相比于无模型自适应控制(model-free adaptive control, MFAC)、Smith预估控制、改进的MFAC控制以及比例–积分–微分(proportional-integral-derivative, PID) 控制方法, 本文方法具有更快的响应速度和更强的鲁棒性. 最后, 通过双容水箱液位控制系统的实验研究, 验证了所提出方法的有效性.     

Synchronization of uncertain MEMS resonators via adaptive time-varying terminal sliding mode control

Microsystem Technologies - The main goal of this study addresses the synchronization between two MEMS resonators with cubic and quintic mechanical stiffness under the existence of system...     

Higher order sliding mode control based on integral sliding mode

A higher order sliding mode control scheme for uncertain nonlinear systems is proposed in the present paper. It is shown that the problem is equivalent to the finite time stabilization of higher order input-output dynamics with bounded uncertainties (r∈N). The controller uses integral sliding mode concept and contains two parts. A part achieves finite time stabilization of the higher order input-output dynamics without uncertainties. The other part rejects bounded uncertainties throughout the entire response of the system. As a result, a higher order sliding mode is established. The advantages of the method are that its implementation is easy, the time convergence is chosen in advance and the robustness is ensured. An illustrative example of a car control shows the applicability of the method.     

非线性不确定系统的非奇异快速终端滑模控制

针对存在非匹配干扰的非线性系统,设计了一种基于干扰观测器和反步法的非奇异快速终端滑模控制.引入非线性干扰观测器估计系统的不确定性,利用反步的思想处理高阶非线性系统,从而可以将非线性干扰观测器估计的干扰值引入反步法的虚拟控制量中,同时设计一种新颖的非奇异快速终端滑模控制律保证系统的收敛速度和精度.利用Lyapunov函数从理论上证明了所设计的控制器可以保证闭环系统的有限时间收敛.最后通过数值仿真验证了所设计的控制方法的有效性.     

Smooth indirect adaptive sliding mode control

In this paper, an indirect approach to the dual‐mode adaptive robust controller (DMARC) is proposed, which combines the typical transient and robustness properties of variable structure systems with a smooth control signal in steady state, typical of conventional adaptive controllers, as model reference adaptive controller. The aim of this indirect version, here named indirect DMARC, is to provide a more intuitive controller design, based on physical plant parameters, as resistances, inertia moments, capacitances, and so on, maintaining DMARC properties. In this paper, a stability analysis for the proposed controller and simulations to an unstable second‐order plant will be presented. Copyright © 2013 John Wiley & Sons, Ltd.     

一种新型逆变器及其滑模控制

提出一种新型逆变器,该逆变器具有拓扑结构简单和控制设计容易的优点,整个拓扑只有一个高频开关,故开关损耗小,且输出电压的幅值可以大于也可以小于输入电压。为了使新拓扑获得很好的动态和稳态性能,在分析其基本工作原理的基础上,对该拓扑的滑模控制进行了研究。最后进行了仿真验证。仿真结果表明,在滑模控制下,新型逆变器对负载扰动具有很好的抑制能力,表现出很好的动态和稳态性能,且输出电压波形谐波含量低,波形质量好,是一种高性能的逆变器。     

集成神经网络与自适应算法的分数阶滑模控制

针对被控对象的参数时变和外部扰动问题,本文融合神经网络的万能逼近能力和自适应控制技术,并结合分数阶微积分理论,提出了基于神经网络和自适应控制算法的分数阶滑模控制策略.本文采用等效控制的方法设计滑模控制律,并利用神经网络的万能逼近能力估测控制律的变化,结合自适应控制算法和分数阶微积分理论抑制传统滑模控制系统的抖震,同时根据Lyapunov稳定性理论分析了系统的稳定性,最后给出了实验结果.实验结果表明,本文提出的基于神经网络和自适应控制算法的分数阶滑模控制系统,能保持滑模控制器对系统外部扰动和参数变化鲁棒性的同时,也能有效地抑制抖震,使得系统获得较高的控制性能.     

基于自适应模糊滑模控制的分数阶混沌系统的投影同步

基于模糊控制理论和滑模控制理论以及自适应控制理论,研究了一类含有外部扰动的不确定分数阶混沌系统的混合投影同步问题.提出了一种自适应模糊滑模控制的分数阶混沌系统投影同步方法.模糊逻辑系统用来逼近未知的非线性函数和外部扰动,并且对逼近误差采用了自适应控制,同时构造了一种具有较强鲁棒性的分数阶积分滑模面.应用分数阶Barbalat引理设计了自适应模糊滑模控制器和参数自适应律.最后数值仿真结果验证了所提控制方法的有效性.     

Robust maneuvering of autonomous underwater vehicle: an adaptive fuzzy PI sliding mode control

The control issues in nonlinear trajectory tracking of an autonomous underwater vehicle (AUV) are a challenging task due to the complex oceanic environment, highly nonlinear coupled dynamics, imprecise hydrodynamic coefficients and unpredictable external disturbances such as ocean waves, current fluctuations and tides. This paper addresses an adaptive fuzzy PI sliding mode control (AFPISMC) for trajectory tracking control of AUV to achieve high precise maneuvering in undersea environment. An AFPISMC is basically comprised of an equivalent control based on approximately known inverse dynamic model output and continuous adaptive PI term is designed to eliminate chattering effect. Furthermore, it does not require a priori knowledge of upper bounds on uncertainties in the dynamic parameters of an AUV. In this approach, decoupled single input fuzzy PI control strategy is employed along with a reduced rule base and self-tuning control law is derived to modify hitting gain in order to enhance tracking response. The overall control scheme guarantees the global asymptotic stability based on Lyapunov theory. Finally, the effectiveness and robustness of the proposed approach are demonstrated through simulation and comparison studies.