Remote Control Guidance Law Design Using Variable Structure Control

A method of sliding mode variable structure control for the missile body being a time varying system is presented. A remote control guidance law is designed. The method has strong robustness to target’s maneuver. To reduce the chattering phenomena, quasi-sliding mode variable structure control method is used. Simulation results show that the proposed method has small miss distance for any kind of maneuvering targets and requires small control energy.

Sliding Mode Variable Structure Control for Visual Servoing System

A visual servoing tracking controller is proposed based on the sliding mode control theory in order to achieve strong robustness against parameter variations and external disturbances. A sliding plane with time delay compensation is presented by the pre-estimate of states. To reduce the chattering of the sliding mode controller, a modified exponential reaching law and hyperbolic tangent function are applied to the design of visual controller and robot joint controller. Simulation results show that the visual servoing control scheme is robust and has good tracking performance.

Adaptive variable structure control based on backstepping for spacecraft with reaction wheels during attitude maneuver

An adaptive variable structure control method based on backstepping is proposed for the attitude maneuver problem of rigid spacecraft with reaction wheel dynamics in the presence of uncertain inertia matrix and external disturbances. The proposed control approach is a combination of the backstepping and the adaptive variable structure control. The cascaded structure of the attitude maneuver control system with reaction wheel dynamics gives the advantage for applying the backstepping method to construct Lyapunov functions. The robust stability to external disturbances and parametric uncertainty is guaranteed by the adaptive variable structure control. To validate the proposed control algorithm, numerical simulations using the proposed approach are performed for the attitude maneuver mission of rigid spacecraft with a configuration consisting of four reaction wheels for actuator and three magnetorquers for momentum unloading. Simulation results verify the effectiveness of the proposed control algorithm.

Adaptive Variable Structure Control of MIMO Nonlinear Systems with Time-varying Delays and Unknown Dead-zones

In this paper, adaptive variable structure neural control is presented for a class of uncertain multi-input multi-output (MIMO) nonlinear systems with state time-varying delays and unknown nonlinear dead-zones. The unknown time-varying delay uncer- tainties are compensated for using appropriate Lyapunov-Krasovskii functionals in the design. The approach removes the assumption of linear function outside the deadband without necessarily constructing a dead-zone inverse as an added contribution. By utilizing the integral-type Lyapunov function and introducing an adaptive compensation term for the upper bound of the residual and optimal ap- proximation error as well as the dead-zone disturbance, the closed-loop control system is proved to be semi-globally uniformly ultimately bounded. In addition, a modified adaptive control algorithm is given in order to avoid the high-frequency chattering phenomenon. Simulation results demonstrate the effectiveness of the approach.

ADAPTIVE VARIABLE STRUCTURE CONTROLLERS AND APPLICATION TO ENGINE IDLE SPEED CONTROL SIMULATION

A neural-network-based adaptive variable structure control methodology is proposed for the tracking problem of nonlinear discrete-time input-output systems.The unknown dynamics of the system are approximated via radial basis function neural networks.The control law is based on sliding modes and simple to implement.The discrete-time adaptive law for tuning the weight of neural networks is presented using the adaptive filtering algorithm with residue upper-bound compensation.The application of the proposed controller to engine idle speed control design is discussed.The results indicate the validation and effectiveness of this approach.

VARIABLE STRUCTURE CONTROL APPLIED IN ELECTRO-HYDRAULIC SERVO SYSTEM WITH ANN

可变结构控制(VSC ) 理论被用于这里的 theelectro 水力的伺服系统。VSC 控制法律用 Lyapunov 方法和杆放置被完成。消除啁啾的现象，浸透功能是。采用。proposedVSC 途径是相当柔韧的装载骚乱和系统参数变化。自从包括的失真，阶段 lag 和振幅变细发生在系统窦状隙反应，振幅和阶段基于 Adaline 神经网络并且用 LMSalgorithm，控制(APC ) 算法为失真取消被开发。APC 控制器简单并且装 on-lineadjust，因此，它给精确追踪。

An Approach to Polynomial NARX/NARMAX Systems Identification in a Closed-loop with Variable Structure Control

Many physical processes have nonlinear behavior which can be well represented by a polynomial NARX or NARMAX model.The identification of such models has been widely explored in literature.The majority of these approaches are for the open-loop identification.However,for reasons such as safety and production restrictions,open-loop identification cannot always be done.In such cases,closed-loop identification is necessary.This paper presents a two-step approach to closed-loop identification of the polynomial NARX/NARMAX systems with variable structure control(VSC).First,a genetic algorithm(GA) is used to maximize the similarity of VSC signal to white noise by tuning the switching function parameters.Second,the system is simulated again and its parameters are estimated by an algorithm of the least square(LS) family.Finally,simulation examples are given to show the validity of the proposed approach.

Approximation law for discrete-time variable structure control systems

为分离时间的可变结构控制系统滑动模式的二条近似法律被建议克服指数的近似法律和可变的率近似法律的限制。由使用滑动模式 todiscrete 时间变量结构控制系统的建议近似法律，起源的稳定性能被保证，并且沿着切换的表面啁啾由分离时间的可变结构控制引起了能有效地被制止。在近似法律设计，系统控制输入被限制的问题也被考虑，它在实际系统是很重要的。最后，一个模拟例子证明二条近似法律的有效性求婚了。

Variable structure control with sliding mode prediction for discrete-time nonlinear systems

新可变结构基于滑动模式预言控制算法因为分离时间的非线性的系统的一个类被介绍。由雇用一个特殊模特儿预言滑动模式价值的未来，；联合反馈修正；是的后退的地平线优化方法广泛地在预兆的控制策略上适用，一条分离时间的可变结构控制法律被构造。靠近环的系统被证明与未特别指出的边界有坚韧性到不确定性。数字模拟；摆钟实验结果说明靠近环的系统拥有需要的性能例如强壮的坚韧性，快集中；啁啾的消除。

Fault detection and accommodation via neural network and variable structure control

This paper proposes a novel idea that classifies faults into two different kinds: serious faults and small faults, and treats them with different strategies respectively. A kind of artificial neural network (ANN) is proposed for detecting serious faults, and variable structure (VS) model-following control is constructed for accommodating small faults. The proposed framework takes both advantages of qualitative way and quantitative way of fault detection and accommodation. Moreover, the uncertainty case is investigated and the VS controller is modified. Simulation results of a remotely piloted aircraft with control actuator failures illustrate the performance of the developed algorithm.

Adaptive variable structure control for large-scale time-delayed systems with unknown nonlinear dead-zone

The problem of adaptive fuzzy control for a class of large-scale, time-delayed systems with unknown nonlinear dead-zone is discussed here. Based on the principle of variable structure control, a design scheme of adaptive, decentralized, variable structure control is proposed. The approach removes the conditions that the dead-zone slopes and boundaries are equal and symmetric, respectively. In addition, it does not require that the assumptions that all parameters of the nonlinear dead-zone model and the lumped uncertainty are known constants. The adaptive compensation terms of the approximation errors are adopted to minimize the influence of modeling errors and parameter estimation errors. By theoretical analysis, the closed-loop control system is proved to be semi-globally uniformly ultimately bounded, with tracking errors converging to zero. Simulation results demonstrate the effectiveness of the approach.

A Novel Genetic Algorithm and Its Application in Variable Structure Control of Robot

A novel genetic algorithm (NGA) is proposed, which possesses micro-regulation and renascence operation. The optimized variable searching interval is regulated gradually according to the sub-group of excellent individuals. The NGA is used to optimize the parameters of the variable structure control (VSC), which satisfies the new reaching law and sliding mode. It is used in robot control systems. Simulation results are given.

Design of variable structure controller for uncertain time-delay singular system

To study the approximation theory of real sliding mode and the design of variable structure controller for time-invariant linear uncertain time-delay singular system,the approximation theory of real sliding mode was developed to provide foundation for obtaining sliding mode by equivalent control,and switching functions with integral dynamic compensators and variable structure controllers were designed respectively under two circumstances that the system without uncertain part was stabilized by delay-dependent and delay-independent linear state feedback. The design guarantees the asymptotical stablity of switching manifolds,and the variable structure controllers can force solution trajectory of the system to arrive at the switching manifolds in limited time. A numerical example is given to demonstrate the feasibility and simplicity of the design method.

VARIABLE STRUCTURE CONTROL OF AIRCRAFTFOR ATMOSPHERIC DISTURBANCE

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Compensation for secondary uncertainty in electro-hydraulic servo system by gain adaptive sliding mode variable structure control

Based on consideration of the differential relations between the immeasurable variables and measurable variables in electro-hydraulic servo system,adaptive dynamic recurrent fuzzy neural networks(ADRFNNs) were employed to identify the primary uncertainty and the mathematic model of the system was turned into an equivalent linear model with terms of secondary uncertainty.At the same time,gain adaptive sliding mode variable structure control(GASMVSC) was employed to synthesize the control effort.The results show that the unrealization problem caused by some system's immeasurable state variables in traditional fuzzy neural networks(TFNN) taking all state variables as its inputs is overcome.On the other hand,the identification by the ADRFNNs online with high accuracy and the adaptive function of the correction term's gain in the GASMVSC make the system possess strong robustness and improved steady accuracy,and the chattering phenomenon of the control effort is also suppressed effectively.

Design of Model Following Variable Structure Controller for Three-axle Vehicle

An optimal control procedure is developed for the front and rear wheels of a three-axle vehicle moving on a complex typical road based on model following variable structure control strategy. The actual vehicle may be considered as an uncertain system. Cornering stiffness of front and rear wheels and external disturbances are varied in a limited range. The model-following variable structure control method is used to control both front and rear wheels steering operations of the vehicle, so that steering responses of the vehicle follow from those of the reference model. By numerical results obtained from computer simulation, it is demonstrated that the control system model can cope with the effects of parameter perturbations and outside disturbances.

VARIABLE STRUCTURE CONTROL OF INDEFINITE-DIMENSIONAL SYSTEMS

ＶＡＲＩＡＢＬＥＳＴＲＵＣＴＵＲＥＣＯＮＴＲＯＬＯＦＩＮＤＥＦＩＮＩＴＥ－ＤＩＭＥＮＳＩＯＮＡＬＳＹＳＴＥＭＳＬｉＷｅｎ－ｌｉｎ（李文林）ＢｉａｎＷｅｎ－ｍｉｎｇ（边文明）（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｔｈｅｍａｔｉｃｓ，ＨｅｎａｎＮｏｒｍａｌＵｎｉ...

Use of nonlinear variable structure control with equivalent term in design of coordinated controls for turbo generators

Presents the coordinated controls of nonlinear variable structure with an equivalent control term designed for turbo generators following the theory of nonlinear variable structure control, which integrates the valve control with the excitation control and reduce the problem of high frequency shiver with conventional variable structure control in addition to a simplified design, and concludes from simulation results that the use of this control can improve the transient of the system.

DISCRETE VARIABLE STRUCTURE CONTROL OF LINEAR TIME-INVARIANT SYSTEMS WITH TIME DELAY

A discrete variable structure control(DVSC) method for the linear time invariant systems with time delay was presented. The continuous time delay systems are first transformed into the standard discrete form which contains no time delay by augmenting the state variables. Then the switching surface is determined by using the ideal quasi sliding mode. As it is difficult for the state trajectory to reach the switching surface exactly, the reaching condition in the form of approach law is used to design the controller. The deduced switching surface and controller contain not only the current step of state feedback but also some former steps of controls. Stability analysis with and without time delay information is also investigated in this paper. Numerical simulation was carried out to demonstrate the effectiveness and feasibility of the presented control method.

Study of Integral Variable Structure Control Method for Stability of SI Engine Idling Speed

The intake air control system of a gasoline engine is a typical nonlinear system, and included among the adverse fac-tors that always induce poor idle-speed control stability are dead time and disturbances in the intake air control process. In this paper, to improve the responsiveness when idling with regard to disturbances, a mean-value engine model (MVEM) with dead time was constructed as the control object, and the two servo structures of sliding mode control (SMC) were studied for better idle control performance, especially in transient process of speed change. The simulation results confirmed that under the constraint condition of control input, the robustness of idle speed control that is being subjected to torque disturbances and noise disturbances can be greatly improved by use of the servo structure II.